A month to herp the jungle...exploring human impacts?

Dedicated exclusively to field herping.

Moderator: Scott Waters

Post Reply
User avatar
jonathan
Posts: 3689
Joined: June 7th, 2010, 8:39 am
Contact:

A month to herp the jungle...exploring human impacts?

Post by jonathan »

If all goes well, I'm going to be spending a month in the Bangladeshi jungle next year. I'll be in a national park with a lot of latitude to do lots of things. It's Lawachara National Park, 12.5 square kilometers of disturbed forest and tea plantation. So far the Bangladesh Python Project in the area has been radiotracking 4 pythons and 7 tortoises, plus it has done a lot of herping that has identified 70+ species of herps in the park, many of them range extensions and even a few country records. There have also been two papers published primarily based on road-kill studies, incidental finds, and calls by villagers, which looked at the composition of the snake populations in the park and their yearly activity peaks. But my month in the park would enable me to do a kind of concentrated herping for an extended time period in a new way, where I'd be likely to produce an additional species or more. Also, I could try to collect enough systematic data during my time that I could write up a paper after I was done. So my questions are....

When should I go? There's a chance that I could go anywhere between April and October, though I may end up being limited to the June/July/August window. Monsoon hits near the beginning of June. A previous road-kill study on snakes in the park showed road-kill numbers peaking in April, July/August, and October. Of course, frogs and caecilians wouldn't have the same peak as snakes. Any thoughts?

If I did a research project, what should I do? I could herp every single day and night for 30 straight days pretty much, so what would be best?

I could do a certain kind of systematic herping on every day.....
Or just hit everything I can think of as hard as I can...
There's a chance I could set up pit-trap arrays or something like that...

any other ideas?
User avatar
jonathan
Posts: 3689
Joined: June 7th, 2010, 8:39 am
Contact:

Re: If you had a month to herp the jungle, what would you do

Post by jonathan »

If you want a better idea of what the place is like, here's my earlier post on the park based on my trip this year:

http://www.fieldherpforum.com/forum/vie ... 0&p=231141

http://www.livingalongsidewildlife.com/ ... oject.html
User avatar
Paul Freed
Posts: 130
Joined: November 10th, 2013, 12:14 pm
Location: Pacific Northwest (Oregon) U.S.

Re: If you had a month to herp the jungle, what would you do

Post by Paul Freed »

Hey Jonathan,
My first question to you would be: what is the purpose of your intended research; i.e. is it for school, for the park, or will you be trying to publish a paper privately? What and how you conduct a project would be based on why you're doing it. I can think of a number of potential projects however, they would be based on what the reason is for doing them. Feel free to shoot me a PM and we can discuss some possibilities. My wife and I are thinking of participating in the July survey at the Lawachara National Park so maybe we can meet up in the field.
-Paul
User avatar
klawnskale
Posts: 1211
Joined: June 7th, 2010, 7:09 pm

Re: If you had a month to herp the jungle, what would you do

Post by klawnskale »

I would do as you suggested in your original post: Set up pitfall trap arrays in predetermined plots. Record along with your species that you find
climate data, time of day you check traps, morphometric data and sex of each specimen, habitat data including vegetation and geographical assessments, any incidental take species representing non herp taxa. Also during your field search time any finds from flipping natural cover, incidental observations in situ from just walking and exploring your research area.
User avatar
Kelly Mc
Posts: 4529
Joined: October 18th, 2011, 1:03 pm

Re: If you had a month to herp the jungle, what would you do

Post by Kelly Mc »

I would be so swept with gratitude and happiness that I would probably cry a little every morning when I woke up. And I don't cry.
User avatar
dery
Posts: 1779
Joined: October 1st, 2011, 12:01 pm
Location: huntsville

Re: If you had a month to herp the jungle, what would you do

Post by dery »

I'd herp nonstop for 48-72 hours except to hydrate and stock up on calories.
User avatar
NatureStills
Posts: 42
Joined: March 19th, 2012, 4:36 pm
Location: Con Dao, Vietnam
Contact:

Re: If you had a month to herp the jungle, what would you do

Post by NatureStills »

You know what I would do Jon (If I had free time between expeditions)? I would do a series of ethograms. You could learn so much just by sitting and watching behavior. Also, its my experience that the quieter you are, the more you find...and you can't get quieter than sitting still. I've been in a lot of jungles and I always just want to sit down and absorb it all in. I think you'd be a perfect fit as you're patient and very detail-oriented. That's my .02 anyhow
User avatar
chrish
Posts: 3295
Joined: June 7th, 2010, 11:14 pm
Location: San Antonio, TX
Contact:

Re: If you had a month to herp the jungle, what would you do

Post by chrish »

If it is just recreational herping with some surveying, I would set aside a plan to herp as many diverse habitats as I could. I would also focus on trying to get good photographs of as many species as I could.

Get a small battery operated recorder (If you need suggestions, PM me). Not only can you record notes in the field, but you can also record the sounds of the jungle. I would record some amphibian calls/choruses. I suspect a lot of the amphibians in that area have never been recorded.

Be open minded. What if it rains 24 hours per day for weeks on end (a real possibility).....or what if the rains don't come and it is unseasonably hot and dry and not easy to herp? What is your plan B, C, D, E....etc. And then adapt those plans once you get there and find out things are not what you expected.

Don't let yourself get burned out by going too hard too fast. You have plenty of time to enjoy herping. Take some time to document the experience (write notes).

Take care of yourself physically while out there. Herping in habitats like that can be tough on a body (and your gear). Stay hydrated, avoid insect bites, make sure you drink and eat wisely (you don't want to spend days sick!).

Mostly savor every moment. It will be the sort of experience you will treasure for the rest of your life. Take great field notes. Write extensive notes daily. Write it all down. Write things you will want to read for yourself later. Years from now you will be glad for every moment you documented.....plus your posts here will be more detailed and enjoyable!
User avatar
jonathan
Posts: 3689
Joined: June 7th, 2010, 8:39 am
Contact:

Re: If you had a month to herp the jungle, what would you do

Post by jonathan »

Everyone has been giving fantastic input so far. I'm going to continue to consider all of it.

Paul also suggested over PM the possibility of studying stomach contents of DOR's, both for diet identification and for parasite identification.

Keep them coming.
User avatar
klawnskale
Posts: 1211
Joined: June 7th, 2010, 7:09 pm

Re: If you had a month to herp the jungle, what would you do

Post by klawnskale »

jonathan wrote:Everyone has been giving fantastic input so far. I'm going to continue to consider all of it.

Paul also suggested over PM the possibility of studying stomach contents of DOR's, both for diet identification and for parasite identification.

Keep them coming.

You can also perform and document this with live herps; especially snakes. As you probably know by now some snakes will voluntarily regurgitate when handled. If you have caught a snake that appears to have recently swallowed a meal you can palpate the snake to make it regurgitate too. I don't recommend doing this with crocodilians though unless it is a small baby :o :lol: It all depends on how far you are willing to go ethically with handling and possibly stressing the herp. Many researchers do perform this procedure because the diet of their study animal could be germane to their studies. You may want to also consider marking captured animals with something non invasive like a non toxic dye or paint dabbed on a toe or tail tip. Formulate some kind of ID code system with colors and varying numbers of toes or tail dabs to ID one individual from another of the same species. This way you will be able to tell later on if you may have previously captured or observed the same animal. Ofcourse, it is also good data to document recaptures and resightings.
User avatar
jonathan
Posts: 3689
Joined: June 7th, 2010, 8:39 am
Contact:

Re: If you had a month to herp the jungle, what would you do

Post by jonathan »

Thinking through the questions more, I've started to focus on a specific idea I want to explore (without pushing out a lot of the good ideas that have already been given).

Lawachara is a small national park. And it's been badly crowded in by human development - villages and rice paddies and tea plantations.

So a question that's really on my mind - is the forest in this park big enough? Are the forest-species that the park is trying to preserve possibly struggling to hold on in such a small protected area?

So one possible way to explore that would be to set up a bunch of standardized pit trap arrays and search transects at various locations close to the forest/human boundaries, and set up another bunch of pit trap arrays and search transects at locations much further from the boundaries, and take a look at how the herp assemblage differs.

I need to take a better look at the whole park in Google Earth to see how that idea might work (I've been looking at the park maps published in previous papers, but they make the lines between different 'natural' and 'human' habitats much neater than they are in real life). But does anyone have any input on this idea?
User avatar
Noah M
Posts: 2293
Joined: November 3rd, 2012, 7:00 pm
Location: Gainesville, FL
Contact:

Re: A month to herp the jungle...exploring human impacts?

Post by Noah M »

Your question of, "Is the forest big enough?" I would think would need a comparative part - looking at this forest and comparing it to one that is bigger and one that is smaller. Or a longitudinal study - are species counts and diversity in decline with human encroachment? A month isn't long enough to do this.

Your herp assemblage differentiation between near human settlement and interior may give you correlation but not causation. Perhaps people settle in certain areas because of better soils and access to water, which might produce a different set of herps than elsewhere. The herps may vary across space not because of the people but because of differences in habitats - the same reason people pick a spot might be the reason a group of herps pick it.

But, there are probably still hundreds of different things you could do.
Take high quality audio recording equipment and see if frog calls vary from one end of the park to the other - are there frog dialects? Genetic differences?

Pick a species and do stomach content analysis, as somebody suggested. This could be great for your human impact studies. Does disturbed forest and tea plantation support key prey species? Are prey species different near disturbed habitat then undisturbed habitat (that is, are the predators using what is available or they prefer a certain item, and how is encroachment affecting this?)

You could go human-environment interaction and look to see how the people encroaching manage the wildlife they encounter. Is there management? If so, what do they do? What are their concerns?

I don't know the area at all, so I don't know how feasible this is, but is the park protecting the species its intending to protect? Set up your pit trap arrays both on the park property and off of the park property, selecting for representative habitat. Is there higher diversity or higher numbers in the park than out? I suggest this because I think similar studies have been done on parks in Africa.

If I think of more, I'll put 'em up here.

Edit to add: Go in with several research plans in mind, but be ready to change or scrap all of it as conditions and situations change. Kinda like, 'Read the instruction manual even if you don't follow it.'
Jacob
Posts: 122
Joined: July 1st, 2010, 8:07 pm

Re: A month to herp the jungle...exploring human impacts?

Post by Jacob »

Maybe I have missed it, since I skimmed through most of this, but:

1. Pit falls take a lot of time and effort to set up.
2. Do you have permits to handle, touch, catch, examine, take and bring stomach contents out of India, etc.?
3. Pit falls take a lot of effort and time.

I would stay away from pit falls if you have not gathered and go with the auditory route. Pit falls require that you know the area properly and what will go on after you leave and even while you are there. Where will you get materials and how will you get said materials in to the park(s)? Will the park even let you start digging or planting these traps? Will this interfere with other wildlife, i.e. ungulates and monkeys? The rains will probably have a factor on the success of these traps. Many things to consider and ask before settling.

Go and make pvc quadrats to RANDOMLY survey leaf litter herps or record anurans in and around the park (disturbed and undisturbed). Then make plan C, D, or E as suggested above.
User avatar
Bryan Hamilton
Posts: 1234
Joined: June 10th, 2010, 9:49 pm

Re: A month to herp the jungle...exploring human impacts?

Post by Bryan Hamilton »

Hi Jacob,

Is there a citation for the PVC quadrat sampling? I've never heard of it and it sounds interesting.
User avatar
jonathan
Posts: 3689
Joined: June 7th, 2010, 8:39 am
Contact:

Re: A month to herp the jungle...exploring human impacts?

Post by jonathan »

Jacob wrote:Maybe I have missed it, since I skimmed through most of this, but:

1. Pit falls take a lot of time and effort to set up.
2. Do you have permits to handle, touch, catch, examine, take and bring stomach contents out of India, etc.?
3. Pit falls take a lot of effort and time.

I would stay away from pit falls if you have not gathered and go with the auditory route. Pit falls require that you know the area properly and what will go on after you leave and even while you are there. Where will you get materials and how will you get said materials in to the park(s)? Will the park even let you start digging or planting these traps? Will this interfere with other wildlife, i.e. ungulates and monkeys? The rains will probably have a factor on the success of these traps. Many things to consider and ask before settling.

Go and make pvc quadrats to RANDOMLY survey leaf litter herps or record anurans in and around the park (disturbed and undisturbed). Then make plan C, D, or E as suggested above.
To clarify:

* Everything is being done in collaboration with Bangladeshi scientists and field workers.
* Nothing will be done without the appropriate permits.
* I know the area to a decent degree and will be working with people who know the area very very well.
* It is certainly possible that other field workers will continue my work after I'm gone if there is a good reason to do so.

All that being said, the intense labor required for making the pitfalls (even with my working thought of 20 linear arrays) and the fact that I can only directly sample them myself for one month is certainly a drawback.

I'm reading some papers on pvc quadrats right now. My largest concern is that the actual number of herps sampled with this method would be too low, especially in Asia. Any random guesses out there on likely # of caecilians/frogs/lizards/snakes per square meter that would be sampled in a disturbed tropical forest with this method?
User avatar
jonathan
Posts: 3689
Joined: June 7th, 2010, 8:39 am
Contact:

Re: A month to herp the jungle...exploring human impacts?

Post by jonathan »

.......
User avatar
jonathan
Posts: 3689
Joined: June 7th, 2010, 8:39 am
Contact:

Re: A month to herp the jungle...exploring human impacts?

Post by jonathan »

captainjack and jacob - I really appreciate your constructive criticism here. Really really helpful.
captainjack0000 wrote:But, there are probably still hundreds of different things you could do.
Take high quality audio recording equipment and see if frog calls vary from one end of the park to the other - are there frog dialects? Genetic differences?

Pick a species and do stomach content analysis, as somebody suggested. This could be great for your human impact studies. Does disturbed forest and tea plantation support key prey species? Are prey species different near disturbed habitat then undisturbed habitat (that is, are the predators using what is available or they prefer a certain item, and how is encroachment affecting this?)

You could go human-environment interaction and look to see how the people encroaching manage the wildlife they encounter. Is there management? If so, what do they do? What are their concerns?

I don't know the area at all, so I don't know how feasible this is, but is the park protecting the species its intending to protect? Set up your pit trap arrays both on the park property and off of the park property, selecting for representative habitat. Is there higher diversity or higher numbers in the park than out? I suggest this because I think similar studies have been done on parks in Africa.
1) I don't know if I have the necessary skills on the frog calls. Another issue is that the habitat transitions along the longest axis of the park, so in my experience many of the frog species are concentrated towards one end of the park or the other. Interesting idea to keep considering though.

2) I'm not going to do stomach content analysis of living specimens, so this particular comparison would probably be too difficult.

3) This is something that the scientists working in the park are already heavily involved in. But I certainly could keep considering how I may help to further their work in this area.

4) This is an interesting thought and I will look at the maps to see if it is possible at all. I'm not sure about the legality or feasibility of doing things outside of park property in this case though.



Keep these ideas coming - they're really good ones. I really want to see if there is a way for me to do something meaningful on the "is this park large enough to protect its herptofauna?" question.
User avatar
jonathan
Posts: 3689
Joined: June 7th, 2010, 8:39 am
Contact:

Re: A month to herp the jungle...exploring human impacts?

Post by jonathan »

I've read a lot more studies now, and I'm seeing enough that make me think that while pitfalls can be productive in south/southeast Asia, quadrats simply aren't feasible for herptofauna. The numbers are low enough (often an order of magnitude below what you would find in Central America) that no real comparison seems possible.

If I can get approval, I'd certainly like to run some pitfalls at the very least in order to try to find species that haven't been recorded in the park.

I'm still looking for some way to design an experiment that would help to test anything related to the effect the the size of the park or the human impacts around the park are having on herptofauna. But, if there's no good way to do that in a month of sampling, oh well.
User avatar
jonathan
Posts: 3689
Joined: June 7th, 2010, 8:39 am
Contact:

Re: A month to herp the jungle...exploring human impacts?

Post by jonathan »

Okay, now I'm thinking about possibly just looking at edge effects. Similar to the study design I talked about earlier, but simply looking at the effects of habitat edges (older forest against disturbed forest and forest) without necessarily drawing conclusions about human influence.

Here is one interesting paragraph that I might want to interact with. This came from a paper specifically dealing with a fragmented urban habitat - in some ways a similar situation to the habitat I want to look at:

"Anthropogenic activities that cause fragmentation processes change the environment on the edges of the forest fragment, and can also cause alterations of some ecological factors, consequently affecting the biodiversity (Laurance & Vasconcelos 2009). Relatively few studies have examined edge effects in amphibian assemblages, despite the expectation that these organisms may be more vulnerable to desiccation in drier environments near edges (Lehtinen et al. 2003). According to Gardner et al. (2007), there is no strong support for the importance of edge effects for amphibians, with a number of studies finding different responses. Studies concerning edge effects on anuran assemblages in different tropical forests indicate reduction in abundance of some species or absence of effects (Gascon 1993, Pearman 1997, Marsh & Pearman 1997, Schlaepfer & Gavin 2001, Toral et al. 2002, Dixo & Martins 2008). Many ecological processes, for example, colonization rate, dispersion and breeding success, depend on the environment around the fragment (Gascon et al. 1999, Laurance & Vasconcelos 2009). Moreover, the fragmentation process reduces genetic diversity even to species with relatively high dispersal abilities, leading to local extinctions (Dixo et al. 2009)."

http://www.biotaneotropica.org.br/v11n2 ... 1022011+en
User avatar
klawnskale
Posts: 1211
Joined: June 7th, 2010, 7:09 pm

Re: A month to herp the jungle...exploring human impacts?

Post by klawnskale »

Jonathan: I heard on NPR there was a major power outage in Bangladesh (just about the entire country). I am assuming you are working off a battery powered laptop or other device. Is it affecting you in any way?
User avatar
jonathan
Posts: 3689
Joined: June 7th, 2010, 8:39 am
Contact:

Re: A month to herp the jungle...exploring human impacts?

Post by jonathan »

I live in India, herp in Bangladesh. Thanks for the concern though! But my Bangladeshi friends seem to be managing to message me still too...I'm guessing the power outage is less universal than it sounds.
User avatar
chrish
Posts: 3295
Joined: June 7th, 2010, 11:14 pm
Location: San Antonio, TX
Contact:

Re: A month to herp the jungle...exploring human impacts?

Post by chrish »

jonathan wrote:Okay, now I'm thinking about possibly just looking at edge effects. Similar to the study design I talked about earlier, but simply looking at the effects of habitat edges (older forest against disturbed forest and forest) without necessarily drawing conclusions about human influence.
If you are there with the beginning of the rainy season, it might be interesting to compare edge effects for amphibian choruses based on levels of anthropogenic noise. There are a couple of published articles about Anthropogenic masking of amphibian calls and their affect on breeding behavior.

You could gather data with inexpensive recorders, analyze it with free software (Audacity), and maybe sample tadpoles diversity/numbers as a measure of reproductive success.

And you always find snakes while you are searching for chorusing frogs. :lol:
User avatar
jonathan
Posts: 3689
Joined: June 7th, 2010, 8:39 am
Contact:

Re: A month to herp the jungle...exploring human impacts?

Post by jonathan »

That's an interesting idea. There is one main road that goes through the park, and LOTS of breeding frogs of quite a number of species breeding on the streams and ponds near it. I don't know how much traffic noise it takes to disturb frogs though - while it is a fairly trafficked road, it's not like there's a constant stream of cars coming through.
User avatar
Noah M
Posts: 2293
Joined: November 3rd, 2012, 7:00 pm
Location: Gainesville, FL
Contact:

Re: A month to herp the jungle...exploring human impacts?

Post by Noah M »

I know Bryan Pijanowski runs the soundscape lab at Purdue. http://ltm.agriculture.purdue.edu/soundscapes_theme.htm

I think he's done work with GIS mapping of sound interference. I would check articles by him if you go the human disturbance on frog chorusing route.
User avatar
jonathan
Posts: 3689
Joined: June 7th, 2010, 8:39 am
Contact:

Re: A month to herp the jungle...exploring human impacts?

Post by jonathan »

Thank you all much for the input you've given here. After getting lots of advice here and in PM's, and reading dozens and dozens of papers, I know tons more than when I started.

In the end I think I'm going to leave out stomach content analysis and frog call studies, due to my own limited skill set in those areas, my uncertainly that the frog call questions can be explored well on this particular site, and wanting to maximize my herping time.

I'm going to use much of the non-focused time on the ethograms idea. I also will take your advice to herp constantly, and be grateful for it all.

And here's the focused idea I'll potentially run with (consider it a work in progress). A few questions are in italics, but how does the main thrust sound?


Previous studies have measured edge effects on amphibians and reptiles in fragmented forest habitat. However, in tropical forests these studies have focused on visual surveys, which inherently select for species which choose exposure. It is possible that semi-fossorial and cryptic species which are rarely seen in visual surveys may respond to anthropomorphic habitat edges in a different manner than exposure-preferring species. This study will use day and night visual examination of strip transects, pit and funnel trap arrays, and arboreal snake traps to comprehensively sample the herptofauna in order to evaluate the herpetological assemblage and relative density at various distances from anthropomorphic habitat edges.

4 sets of study areas on forest habitat edges – (possibly do tea plantation edges on all four, or perhaps include a village/rice paddy edge). Each set will involve 3 linear drift fence arrays (12 meters of plastic fencing with 2 5-gallon buckets and 2 double-funnel traps), 3 arboreal snake traps, and 3 50 meter long strip transects. The drift fence arrays and arboreal snake traps will be separated by 50 meters with the strip transects alternating between the arrays. The three trap arrays will be placed at 10 meters, 20 meters, and 50 meters from the forest edge. Transects will extend for 50 meters perpendicular from the habitat edge. Still have a few questions on drift fence specifics.

8 study areas will be in forest interior, at least 250 meters from the nearest habitat edge. Each study area will involve 1 drift fence array, 1 arboreal snake trap, and 1 50 meter strip transect. There will be one pair of interior sites for each edge site, located in the same general part of the forest. Still working on exactly how to choose the sites.

Study will run for 24 days. 1 edge study area (3 transect strips) and 2 interior study areas will be visually sampled each day, resulting in every strip being visually sampled once every 4 days for 6 total samples at each site (half day, half night). Conceivably, I could double the sampling effort if necessary.

One more question - how much plant and microclimate sampling/analysis do I want to do in each site? I could of course go with "none", or do so much that it wiped out the herping. Is there a small amount that be useful in itself, or should I just forget about it?
User avatar
chrish
Posts: 3295
Joined: June 7th, 2010, 11:14 pm
Location: San Antonio, TX
Contact:

Re: A month to herp the jungle...exploring human impacts?

Post by chrish »

jonathan wrote:That's an interesting idea. There is one main road that goes through the park, and LOTS of breeding frogs of quite a number of species breeding on the streams and ponds near it. I don't know how much traffic noise it takes to disturb frogs though - while it is a fairly trafficked road, it's not like there's a constant stream of cars coming through.
You could compare frog densities and tadpole numbers at the different sites. Obviously with little in the way of control populations, you would need a big dataset but it might be do able.

You could also just score a chorus index for each species at each pond, although that many not be predictive of reproductive success. That's why some measure of egg/tadpole success might be useful. For direct developers it will be tougher.
User avatar
Bryan Hamilton
Posts: 1234
Joined: June 10th, 2010, 9:49 pm

Re: A month to herp the jungle...exploring human impacts?

Post by Bryan Hamilton »

jonathan wrote:One more question - how much plant and microclimate sampling/analysis do I want to do in each site? I could of course go with "none", or do so much that it wiped out the herping. Is there a small amount that be useful in itself, or should I just forget about it?
I think it depends on what you know. If you have some a priori reasons to think that vegetation and microclimate vary with distance from edge AND you have some reason to believe that these differences will affect herps, then go for it. Collect statistically defensible data along with your herp sampling. For example there might be less cover or more invasive plants near the edge of the park and this could affect herp diversity.

If however you are phishing, I wouldn't waste time on it. A lot of us, including myself, start out thinking that is some secret plant or temperature that can explain differences in herp diversity or distribution. We have no idea what we're looking for but we look anyway. Usually by collecting as much data that we can, water quality, temperature, plants, ect. Sometimes we find something but usually not. The better strategy IMO is to have some prior information THEN go out and see if there is a relationship.

Have you considered setting up your study in an occupancy framework? Then you can control for detectibility and avoid some of the issues you bring up. It might be a cleaner way to get at some of your questions.
User avatar
jonathan
Posts: 3689
Joined: June 7th, 2010, 8:39 am
Contact:

Re: A month to herp the jungle...exploring human impacts?

Post by jonathan »

Bryan Hamilton wrote:Have you considered setting up your study in an occupancy framework? Then you can control for detectibility and avoid some of the issues you bring up. It might be a cleaner way to get at some of your questions.
I think there may be aspects of setting it up within an occupancy framework that I don't understand yet.

From what I do understand, I would try to predetermine which factors will affect the detect-ability of my target species in any particular survey, and then try to select conditions/sites/target species with and without those factors in order to develop an equation that accurately predicts the relationship between detection and actual occupancy?

Or could I set up the data within an occupancy framework without that affecting the selection of sites?
User avatar
Bryan Hamilton
Posts: 1234
Joined: June 10th, 2010, 9:49 pm

Re: A month to herp the jungle...exploring human impacts?

Post by Bryan Hamilton »

jonathan wrote:I think there may be aspects of setting it up within an occupancy framework that I don't understand yet.

From what I do understand, I would try to predetermine which factors will affect the detect-ability of my target species in any particular survey, and then try to select conditions/sites/target species with and without those factors in order to develop an equation that accurately predicts the relationship between detection and actual occupancy?

Or could I set up the data within an occupancy framework without that affecting the selection of sites?
I don't know much about occupancy either I still need go to occupancy school but it seems to be a really nice sampling method, especially for shorter studies like yours. You can get a lot of baseline data, account for detectibility, and avoid some of the issues associated with using density or other population indices.

The beauty is that there won't be much change in your sample design, except for visiting your sites multiple times. By doing that you'll get detectibility and you can relate that back to the environmental variables.

edit- Your response variables are reduced to presence - absence with occupancy. But you would still want to keep track of abundance.
User avatar
jonathan
Posts: 3689
Joined: June 7th, 2010, 8:39 am
Contact:

Re: A month to herp the jungle...exploring human impacts?

Post by jonathan »

Okay, if I'm understanding your summary and the papers correctly now then that indeed is a rather easy way forward. I wonder how it would fit into a edge study though - I guess I would break down presence/absence at distinct distance ranges from the edge - 0 to 10 meters, 10 to 20 meters, etc.?
User avatar
Bryan Hamilton
Posts: 1234
Joined: June 10th, 2010, 9:49 pm

Re: A month to herp the jungle...exploring human impacts?

Post by Bryan Hamilton »

jonathan wrote:Okay, if I'm understanding your summary and the papers correctly now then that indeed is a rather easy way forward. I wonder how it would fit into a edge study though - I guess I would break down presence/absence at distinct distance ranges from the edge - 0 to 10 meters, 10 to 20 meters, etc.?
Something like that, you would want to bin the data somehow for comparison.
User avatar
gbin
Posts: 2292
Joined: June 10th, 2010, 4:28 pm

Re: A month to herp the jungle...exploring human impacts?

Post by gbin »

I see there are two threads currently running on more or less the same subject. This seems the more general thread (the other appears to be focusing specifically on drift fence and pitfall trapping), so I'll put my comments here. My apologies for chiming in so late, but I was traveling most of the time the thread has been up and I wanted to wait until I could give it the serious attention it deserves.

As always, jonathan, I absolutely love your passion and work ethic! Keep in mind, though, that sometimes the flip side of our personal strengths is our personal weaknesses. The bottom line: I think what you're laying out to do during your month in the Bangladeshi jungle is awfully ambitious, perhaps unrealistically so. I urge you to focus on something relatively small and aim to do that particularly well rather than on something large or many somethings which you'd end up doing much less well - and maybe so poorly that you're left simply frustrated and exhausted at the end of all your hard work. People who hurry and/or otherwise overdo in difficult working environments (which definitely include tropical forests) often end up downright hurt or worse, too.

You mentioned somewhere that getting official permission to do whatever you want to do will be no problem. I thought that way myself - once upon a time. I still thought that when it ended up taking months instead of weeks to get all my permits lined up before I headed for Guatemala to work in its Tikal National Park. I even still thought that when at the end of those months officials there said "We can only give you these permits before you get here," (yes, multiple permits from multiple offices were required), "but we can give you those permits just as soon as you arrive." I learned my lesson, though, when I had to make a special trip and fly down to get "those" permits - and it took weeks more to get them - just so I could fly back to the U.S., pick up all my stuff and finally drive down to begin my work. I've known too many other graduate students and professional scientists who have encountered similar difficulties in a variety of other locations too many other times to write off what happened to me as just bad luck. Indeed, I've come to think of it as the norm for wildlife field studies, especially those abroad.

I suppose it's possible you might be facing something extraordinarily streamlined, simple and sure, but for my part I wouldn't at all count any chickens before they've both hatched and I have them firmly in my possession. You're talking about working as a foreign biologist (even if on an amateur basis) in one of Bangladesh's national parks. I would expect that to require at least a couple of permits, more if you plan to collect specimens of anything, and still more if you plan to export any data or specimens back to the U.S.

And you can't completely trust Bangladeshi friends/colleagues there who say it will be no problem to get the necessary permits or who might even say they've already all such permits in hand. Ask for copies of the permits, and read them carefully (get them translated to English if necessary so that you can do so) to see if they really cover you and what you'll be doing specifically. Don't let yourself believe they will exist until they actually do. Don't let yourself believe they do exist until you actually have them in hand. My wife and I still adopt the voice and phrase of a Central American colleague who we tried hard to work with and who told us time and again "There's no problem!" (when there was in fact nothing but problems that said colleague actually had no idea how to overcome) whenever we think we or others are being naive, and then we laugh in a a not-very-happy way. Disregard this advice at your own peril.

And if you plan to make a career for yourself as some kind of wildlife biologist, I strongly urge you not to act in any way that circumvents Bangladeshi or U.S. law, e.g. to "stretch" a colleague's permit beyond reason or to simply try to work without a permit, i.e. "under the radar," nor to allow others to do so on your behalf. Yes, I know people who have smuggled data/samples back from foreign lands, and I know even more who have paid bribes to grease the wheels of whatever bureaucracy they're trying to deal with to enable them to obtain such data/samples. But 1) the ramifications of getting caught doing such - and people do get caught from time to time - would be terrible for your aspirations, 2) by doing such you would contribute to the already bad name U.S. field researchers have in some places (and to the onerous rules and regulations those places develop as a result), and 3) you wouldn't learn much about the proper way to do things, which in my opinion should be one of your main goals at this point. The permitting process can be a tremendous slog to get through, but it's worth doing things right.

Suppose you do have all the T's crossed and I's dotted on your paperwork just as soon as you arrive there. You're still faced with an awful lot to learn and an awful lot of work to do in a very short time. A month in the field goes by in the blink of an eye even when one is experienced in the tasks one must perform and the environment one must perform them in. It's awesome that you already have at least some experience where you'll be going. That will definitely improve the learning experience for you, maybe even quite a bit. Likewise the fact that you already know people there. But make no mistake, a learning experience is what it will first and foremost be. If you try to conduct any kind of actual study, think of it as at most a pilot study, meant to examine the feasibility and learn all the ins-and-outs that would be required for a larger, more meaningful study. For example, as much as you can learn from books and papers and the advice of others before you go, that's still only a starting point for you to try some things there to find out for yourself exactly where and in what kind of array to set up drift fences and pitfall traps, and what doing so will really entail. (I must say, the comment you made somewhere to the effect of "I don't think the ground there is very hard" smacked to me of famous last words, and that's just one small aspect of drift fence and pitfall trapping.)

On the topic of drift fence and pitfall trapping and other means of sampling herps, I think it's great that you've already read some focused papers. I worry a bit, though, that you're putting the cart before the horse in terms of not getting a better handle on the basics before seeking refinements appropriate to what you want to do and where you want to do it. I know these book titles were recommended elsewhere, but I want to repeat them because I think you should seriously consider getting your hands on and studying extensively from them:

Measuring and Monitoring Biological Diversity. Standard Methods for Amphibians (Biological Diversity Handbook), W.R. Heyer et al. (Eds.), 1994

Amphibian Ecology and Conservation: A Handbook of Techniques (Techniques in Ecology & Conservation), C.K. Dodd Jr. (Ed.), 2009

Reptile Biodiversity: Standard Methods for Inventory and Monitoring, R.W. McDiarmid et al. (Eds.), 2012

I recommend you study these books for three reasons. First, although the focused papers and advice you've been taking in so far are definitely useful, these will put what you've been learning thereby into much better context, as you'll much better understand why certain placements/arrays of drift fences and pitfall traps are particularly useful for these kinds of questions and why certain others are particularly useful for those kinds of questions. You'll also come across answers to all kinds of questions you haven't yet thought to ask and no one has yet thought to answer for you. In other words, your time in Bangladesh will be a solid part of a good overall understanding of this method for sampling herps rather than just your taking a stab at something you kind of understand and really want to learn about and apply. Second, these books will expose you in perhaps equally rigorous fashion to other methods which you just might end up deciding are more appropriate for studies you'd like to do in your Bangladeshi national park. Drift fence and pitfall trapping is great, to be sure, but there are other great techniques, too. The particular question being asked and the particular setting in which you hope to answer it should really dictate which method(s) should be applied. Third, these books will put all of this, from the initial formulation of questions all the way through the application of whatever methods to answering them, in a statistical context. I can't tell you how often I've tried to advise undergraduates, and even a couple of graduate students (and one professional scientist!), on how best to statistically analyze their study results only to find that the way they designed and carried out their studies resulted in them actually only having a sample size of N=1 (making no statistical tests possible) or in them having done things which violated essential components (e.g. randomness) of any of the statistical tests that otherwise could have been performed. You really don't want this to happen to you. The solution is to devise a study and choose its methodology with its statistical test(s) in mind from the start, and frankly I don't think you're ready to do that.

I don't mean to be a wet blanket, jonathan. I think it's wonderful that you have this opportunity and want to do as much with it as you possibly can. I want that for you, too. I just think you'll get much further if you walk with your two feet solidly beneath you before you try to run. Truthfully, if it were me headed there when I was still a graduate student I'd quite likely be hoping to do just as much as you're planning on. But time and experience lend wisdom. Now I'd aim much smaller and doubtless have a much more productive - and fun - trip. My recommendation to you:

Use the time between now and your trip to do general but in-depth study of herp sampling methods, and to make sure - and I mean absolutely sure - that all the paperwork is squared away that will allow you to do what you want to do there, be it drift fence and pitfall trapping or whatever. Then use the time there to actually explore the herp sampling methods that seem most promising to you for the kinds of questions that seem most interesting and relevant in that situation. Try some trap lines in various locations, orientations and arrays. Similarly try some transects of various sizes in various locations, smaller for critters in the leaf litter (again, I can tell you that finding tiny frogs in even just 1 sq. m. samples of leaf litter takes more time than you'd expect), larger for critters up on the surface and capable of being found by visual scanning. Think about, maybe even try (if permitted) cutting a transect or two, or using paths/roads/canals/what-have-you as transects already available at your location. Focus specifically on trying various techniques so you'll know just what works best and for what purposes on future visits. That would be a very productive trip given your time frame, I think.

I know, you really want something more tangible to show for your time there. I would, as well (back when I was still a graduate student and didn't know better). If you do as I suggest you'll certainly have something more tangible, too, though. I don't know whether your Bangladeshi national park currently has a herp species list, but if it does I bet it isn't at all thorough and you could add substantially to it during your exploration of sampling techniques. And if it doesn't you could use the results of your explorations to create one for them. That would be useful to them, and to you if you end up doing future studies there.

I wish you the best of luck whatever you end up trying to do or doing. I'm happy to give you more specific advice as you wish, too, but what I've offered above is I believe the best I have to offer you even if it's not what you want to hear. In any event, of course, please understand that it is my intent to give you the best advice I can and not to make you unhappy. Please understand, too, that I fully recognize how very bright and motivated you are. That's not the issue at all (or I wouldn't dream of recommending that you undertake home study of herp sampling methods/study design); it's simply that a month isn't enough time to learn everything you'll still need to learn once you get there and then put it to use in a meaningful scientific study. That's what I believe based on my own field work experience and that of others I've known through the years, anyway.

Gerry
User avatar
jonathan
Posts: 3689
Joined: June 7th, 2010, 8:39 am
Contact:

Re: A month to herp the jungle...exploring human impacts?

Post by jonathan »

Gerry - thanks for the huge amount of effort you expended writing up all of that for me! Very much appreciated!

gbin wrote:As always, jonathan, I absolutely love your passion and work ethic! Keep in mind, though, that sometimes the flip side of our personal strengths is our personal weaknesses. The bottom line: I think what you're laying out to do during your month in the Bangladeshi jungle is awfully ambitious, perhaps unrealistically so. I urge you to focus on something relatively small and aim to do that particularly well rather than on something large or many somethings which you'd end up doing much less well - and maybe so poorly that you're left simply frustrated and exhausted at the end of all your hard work. People who hurry and/or otherwise overdo in difficult working environments (which definitely include tropical forests) often end up downright hurt or worse, too.
Don't worry all too much about that. I will not go all the way to Bangladesh without spending most of my time herping, and I've gotten experienced enough in placing myself in very difficult working environments so I'm well aware of where my limits lie and how to maximize my own enjoyment. (one reason why I had to end up rejecting the stomach content idea among others). And I won't implement a study design unless I'm certainly that it's been planned tightly enough to do well, with plenty of leeway, within the constraints I'll have. Without knowing me better you couldn't know that of course, so it's certainly very good advice. I'll also likely have a couple advantages in terms of working environment and on-ground partners that I haven't mentioned (because I have to make sure they come through first).


gbin wrote:You mentioned somewhere that getting official permission to do whatever you want to do will be no problem.....
Just to partially alleviate your concerns in this direction...

1) I'm definitely not thinking that getting all the necessary permissions will be no problem. Getting permission to work in the park should be no problem unless something really extraordinary happens, but failing to get specific permission to run drift fence arrays is my biggest fear. What I'm tried to emphasize earlier is that I absolutely will not start something like a drift fence array without the proper approval. However, I'm ignoring that side of things in these threads because I have to have a clear plan for what I want to do before I can ask permission to implement the plan, and because no one here can help me with those specifics in this scenario.

2) As far as the comments you make about trusting my local partners on the ground, I can only say that I certainly understand where your concerns come from and where they would be applicable in many situations, but in this particular case there are people on the ground who I can trust more than I'd trust any American partner.

3) Also, it's not the typical "foreign scientist trying to do research overseas" sort of situation.
This isn't my first trip here - I've already down work at the site (with the official permission I needed) and am making this second trip after being personally invited to return. I live in close cultural (and lingual) proximity to Bangladesh and have more flexibility than most do in that regard - for instance, I'm only spending $60 on my flight to get there! I'm not starting a new research project, but merely revisiting and expanding an ongoing research project that has already been operating in the park for 4 years. It is the Bangladeshi friends of mine who are leading that project and who will be getting all the necessary permission in their names, not mine - the only point at which my name comes in will be in the document requesting permission for the foreign herpetologist to come and live in the park in order to assist in the project. And the relationship is already strong enough that the park should be covering my room and board for free, which gives you an idea of the partnership that is already in place.


gbin wrote:And if you plan to make a career for yourself as some kind of wildlife biologist, I strongly urge you not to act in any way that circumvents Bangladeshi or U.S. law, e.g. to "stretch" a colleague's permit beyond reason or to simply try to work without a permit, i.e. "under the radar," nor to allow others to do so on your behalf. Yes, I know people who have smuggled data/samples back from foreign lands, and I know even more who have paid bribes to grease the wheels of whatever bureaucracy they're trying to deal with to enable them to obtain such data/samples.....
I don't pay bribes in any circumstances. I won't put up any drift fences or dig any pit traps without specific permission to do exactly that. And all samples will be kept by local scientists - I have no need to bring samples back to India!


gbin wrote:If you try to conduct any kind of actual study, think of it as at most a pilot study, meant to examine the feasibility and learn all the ins-and-outs that would be required for a larger, more meaningful study...
Yeah, I'm aware that it might boil down to that in the end. On one hand, I'd like to design the study so that it could bear some completeness in itself for this month. On the other hand, I'm aware that the reality may be that in the end I have to make several trips back and change certain expectations in order to learn the things I really want to learn, or to get anything remotely publishable done.

And to be clear, I've dug in this ground before. Not everywhere in the park, and not to the depths required, but enough to get an initial feel for it. I also saw local guys dig five pits there in rapid fashion, with each pit large enough to fit several people, many times larger than anything I'll need. And other than possible root structure in some places, I haven't seen any reason to suspect that any other spot will be significantly more difficult to dig in. (The pits were fairly central the general area I'll want to be looking at. I checked them for several days until they were filled, and found 3 species of frog and 1 species of skink trapped in them in decent numbers.)


Thank you much for the book recommendations, and I certainly understand why you see them as a baseline for anything else. Unfortunately, it may simply be difficult to acquire them logistically from here. I can do anything electronically, but getting mail to arrive in my city is a crapshoot, and I won't be in the USA between now and the project. I think my Bangladeshi friends already own some or all of them, and see what we can work out in terms of communication with that. I get what you say about their importance as a baseline before any other specific questions are asked though.


Thank you much on the rest of your recommendations, and they certainly make a lot of sense. (I will throw in that that ongoing research project that I'll be entering into has already expanded the park's herp species list from 10 to 70+!)
User avatar
gbin
Posts: 2292
Joined: June 10th, 2010, 4:28 pm

Re: A month to herp the jungle...exploring human impacts?

Post by gbin »

Thanks in turn for taking my advice as it was intended (even where you felt it didn't really pertain to your situation), jonathan. :beer:

And for explaining the situation more fully to me, too. I do feel I understand better now. So, assuming for the sake of discussion here that you have or will acquire with your Bangladeshi colleagues whatever permits you need, let's drill down...

It sounds to me, too, as if the most useful focus for you would be on fossorial, arboreal or just plain cryptic species that don't often turn up on roads or in visual surveys. Drift fence and pitfall trapping might indeed be the way to go, but don't discount quadrat sampling - especially if you encounter any difficulties getting the trapping going. (And briefly on the subject of quadrat sampling: I had the good fortune to find in a market an hour away from my national park in Guatemala a big but lightweight metal tub with high sides - you know, as one might use for hauling/washing laundry or whatever - that had very nearly a 1-square-meter bottom. I carefully measured and cut the bottom out of it going up its sides just a smidgen to achieve a precisely 1-square meter opening, and used it for my quadrat sampling. It wasn't quite as easily portable as a wooden or PVC quadrat frame would have been, of course, but it wasn't difficult either, and I loved it because it worked perfectly to prevent escapes by the more mobile critters in my samples. You might take a look around the neighborhood of your national park to see if you can get equally lucky in finding something to use similarly.) I'm afraid I know virtually nothing about arboreal trapping.

Have you one or more decent maps of your national park and the area immediately surrounding? These could really help you with your planning where to sample, at the very least if they show water courses/bodies and some topography but especially if they include any information on habitat. For example, unless you collect an awful lot of samples, variance in results caused by differences in habitat type or the presence of edges or other disruptions in habitat could really swamp any investigation you try to make of a question such as "how do herp species/numbers compare between the park's edges and its center?"

Do you know fairly precisely where you'll be at in terms of your forest's seasonality? There's not anything you can do about this, of course, but it could certainly affect where/how you choose to sample, and you should go into it realizing it could hugely affect your sampling success no matter what you end up doing, too. Did I understand correctly that if you were to set up some traps then folks could continue to work them after you leave? That would help a heck of a lot with the seasonality issue. It could also affect trap placement, e.g. you probably wouldn't want to set traps in a place that would work fine for your visit but would be underwater when things get wetter. (Speaking of which, what about sampling for aquatic herps? I don't recall you mentioning anything about them.)

Are you sure there's no way some textbooks could get to you so you can study up more in advance? Even if we here were to try to help somehow? And/or if friends/colleagues where you currently are were consulted on the matter? I'm willing to help if I can, and I'm sure others here are, too.

One more comment before ending this post and leaving behind the topic of permits: If it's your colleague(s) with the permits, it could nonetheless help you to be specifically named in them rather than just having them cover you as some unnamed assistant. You should also avail yourself of any opportunities that arise to personally meet the permitting authorities, too, even if it pulls you out of the forest for a day or two here and there. Having your name, handshake and friendly smile get around among important people (and permitting authorities are important people no matter where exactly they stand in their bureaucracies' hierarchies) now could do much for you in the future.

Gerry

P.S. I figured from what I'd already learned of you here at FHF that you would want to do everything the right way, e.g. with respect to permits. I had to bring it up, though, because people have certainly surprised me in the past in this regard. I once attended a party with my fellow graduate students where a circle of them started bragging to one another how they'd cleverly sidestepped this or that legal requirement in their work abroad, and I was shocked and appalled. I let them all know what I thought of their misdeeds then and there, too, in no uncertain terms - talk about being a wet blanket! :lol: One or two of them determinedly avoided me thereafter, but some of them to their credit made a point to look me up to acknowledge their mistakes both in acting illegally and bragging about it at that party, and promised to do better henceforth. We're all role models or at least representatives of the various aspects of ourselves whether or not we wish to be, after all.
User avatar
jonathan
Posts: 3689
Joined: June 7th, 2010, 8:39 am
Contact:

Re: A month to herp the jungle...exploring human impacts?

Post by jonathan »

Thanks again Gerry!
gbin wrote:It sounds to me, too, as if the most useful focus for you would be on fossorial, arboreal or just plain cryptic species that don't often turn up on roads or in visual surveys. Drift fence and pitfall trapping might indeed be the way to go, but don't discount quadrat sampling - especially if you encounter any difficulties getting the trapping going.
The issue I'm fearful of there is that literally every paper I've read involving quadrat sampling for herps in Asia has turned up almost nothing. Sometimes it's even been abandoned mid-study because the results were so poor. Herp density here is just much lower, and that especially shows up in that method. When herps were found in quadrats, they were often pretty much the same herps that were found in visual searches. So I feel that making 50-meter strip transects (where I use a pre-determined time period to repeatedly visually search for every herp within a 3-meter or 6-meter strip) has a much better chance both of finding herps (the fun aspect) and of getting enough herp numbers that I can actually make comparisons.


gbin wrote:Have you one or more decent maps of your national park and the area immediately surrounding? These could really help you with your planning where to sample, at the very least if they show water courses/bodies and some topography but especially if they include any information on habitat. For example, unless you collect an awful lot of samples, variance in results caused by differences in habitat type or the presence of edges or other disruptions in habitat could really swamp any investigation you try to make of a question such as "how do herp species/numbers compare between the park's edges and its center?"
Previous studies have mapped the habitat and categorized it generally as disturbed forest, mature forest (which just means that it was disturbed a bit further in the past), tea plantation, rice paddy, and village. That mapping matches what I saw on the ground there, but I'm reading through a few other studies that might have even more specific vegetation data available for me. I also have a decent idea of the topography and waterways from Google Earth and my own time on the ground.

Here's a big issue though, and one that I'm going to have to spend a lot of time figuring out. Exactly what about the habitat matters enough to take into account? This goes past the vegetation issue. There are quite a lot of streams distributed well within the habitat, and they're uniformly rather small. So can stream proximity be considered to be a fairly homogeneous characteristic that can be ignored after a certain minimal distance? And what is that distance? How about hill slope? Is a certain slope okay, or do I need to find a flat spot, or do I need to go so far as to find a flat spot that also is not to proximate to a slope?

Or, with 12 edge plots and 8 interior plots, can I have enough replicates that random or systematic placement will be good enough to even out differences so long as everything's within the same forest type? (even in that case, I would make note of key differences and test the data with and without outliers afterwards to see if any of those differences indeed appeared to have skewed the data.)

So yeah, this is certainly something I need a lot more time on.

gbin wrote:Do you know fairly precisely where you'll be at in terms of your forest's seasonality? There's not anything you can do about this, of course, but it could certainly affect where/how you choose to sample, and you should go into it realizing it could hugely affect your sampling success no matter what you end up doing, too. Did I understand correctly that if you were to set up some traps then folks could continue to work them after you leave? That would help a heck of a lot with the seasonality issue. It could also affect trap placement, e.g. you probably wouldn't want to set traps in a place that would work fine for your visit but would be underwater when things get wetter. (Speaking of which, what about sampling for aquatic herps? I don't recall you mentioning anything about them.)
I will be there close to the beginning of monsoon, a very good time for many species. Whether or not other people will work the traps after I leave will be a matter for discussion and would be fantastic. However, if all goes well I might come back a different month the next year, and so on - perhaps replicating the study in an April (beginning of hot season), an August (end of monsoon), and an October (ideal post-monsoon, hatchling season) to get a full array of results from the major herp activity periods. The previous road-kill survey in the area ran for 14 months and gave a very good picture of the snake activity patterns in this particular forest. I also like the idea of repeating in the same month 5 years down the road and so on, so we eventually get some long-term longitudinal data.

From what I can tell, the only aquatic herps would be in the rice-paddies outside of the forest, where I will not be sampling.


gbin wrote:Are you sure there's no way some textbooks could get to you so you can study up more in advance? Even if we here were to try to help somehow? And/or if friends/colleagues where you currently are were consulted on the matter? I'm willing to help if I can, and I'm sure others here are, too.
That is very kind of you. If there's a way, I would be happy for anyone who wants to pitch in. My big concern is that I live in India, not near a major airport, and over 1/2 the international mail that is sent to me fails to arrive. So having someone purchase a pricey book, spend a bunch more money to airmail it across the world, and then have it not arrive would be a real downer.


gbin wrote:One more comment before ending this post and leaving behind the topic of permits: If it's your colleague(s) with the permits, it could nonetheless help you to be specifically named in them rather than just having them cover you as some unnamed assistant. You should also avail yourself of any opportunities that arise to personally meet the permitting authorities, too, even if it pulls you out of the forest for a day or two here and there. Having your name, handshake and friendly smile get around among important people (and permitting authorities are important people no matter where exactly they stand in their bureaucracies' hierarchies) now could do much for you in the future.
Yeah, last time we had a greet-and-meet with the local authority right when we got there and a little celebratory dinner with the big national guy on our way out. I would be certainly specifically named in the request to work on the project - that's necessary because I would live on-site - it's just that the request for my presence and the request for the trap permission would be two different requests. But because of a certain "in" that I have, it might end up being quite an advantage to name me on the trap request too.

Thanks again for the detailed thoughts!
User avatar
gbin
Posts: 2292
Joined: June 10th, 2010, 4:28 pm

Re: A month to herp the jungle...exploring human impacts?

Post by gbin »

Ok, I've looked over your responses here and by PM and thought things over a bit more. I hope you don't mind if I just respond here to try to keep everything in one place and to enable others to help you spot where I might be saying something that's actually irrelevant to your situation or just plain ignorant (hey, it happens from time to time ;) ). To save time, too, I'm not going to try very hard to organize my comments but instead just aim to cover everything that I think I have something to say about; sorry if that makes my comments harder to assimilate. I'll avoid discussing any information you might deem sensitive here.

As I understand you, your strip transects are actually going to be time-limited surveys; otherwise they're really just long, skinny quadrats. (I understand your concern about low herp densities making quadrat sampling ineffective, but you never really know until you try, and it's an easy, low-cost, -tech and -disturbance method that everyone readily understands, so I recommend that you keep it as a back-up, anyway.) To get at the herps living in or just beneath the leaf litter, though, how would a time-limited survey work? Sifting through leaf litter for potentially small organisms is time consuming, with the larger the area being searched of course being the more so. I don't know of any way around that short of trapping.

The (near-)surface activity of such organisms are so dependent on two things which vary seasonally - the amount of leaf litter and its moisture content (because of the food, water and cover they provide) - that you might want to measure those directly, too. Data on these tropical forest metrics can potentially do a lot better job of accounting for seasonal variance in results than can time of year, as years always vary at least somewhat from one another in terms of the beginning, ending and severity of their seasons, and some kinds of the vegetation that produce the leaf litter often follow their own supra-annual cycles, too (though this generally affects flower/fruit/nut production more than leaf production). What I did when I was sampling leaf litter organisms was to actually scoop up and bag a 1-sq-m quadrat sample, weigh the bag freshly collected, sort through it to find all the organisms visible to the naked eye (I was interested in invertebrates, too - and man, was that a lot of work!), spread the leaf litter out in a sunny spot protected from the wind until it was thoroughly dried, and then re-bag and reweigh it. That gave me data on leaf litter mass and leaf litter moisture content as well as on the organisms it contained. So you might want to collect such samples for leaf litter data even if not for herp data. ;)

Related to this topic, I don't know how much you've studied tropical forests in a more general sense, e.g. their ecology, seasonality and so forth, so I'm going to recommend another book title to you. This is one I found extremely useful for getting me up to speed. It stems from long-term studies at a particular Central American site, Panama's Barro Colorado Island, but the basic lessons are broadly applicable, and I reckon many of the specific methodologies are as well. Maybe this suggestion will prompt someone in the know to suggest a title more appropriate to your location, too:

The Ecology of a Tropical Forest: Seasonal Rhythms and Long-Term Changes, E.G. Leigh Jr. et al. (Eds.), 1996

And not to beat a dead horse, but you would greatly benefit from figuring out a way to get your hands on some of these books, even at your present location with its poor mail service. Maybe people you know who will be coming and going could carry books to you? Maybe you could use a (somewhat) more expensive but (hopefully much) more reliable shipper?...

I've more to say but suddenly no time now to say it; I'm being called away for errands. Sorry! One quick thing before I go, though, in case you want to respond to it before I return: As I understand you, you want to compare the number, type and abundance of herp species just within the park's borders to those in the park's center. All I've seen you write, though, is about "edges," which I think you're using for discussing both those borders and habitat changes. I'd recommend being careful to use "edge" strictly for discussing the habitat, and "border" (or "boundary," if you prefer) for discussing the geography.

More later, then...

Gerry
User avatar
jonathan
Posts: 3689
Joined: June 7th, 2010, 8:39 am
Contact:

Re: A month to herp the jungle...exploring human impacts?

Post by jonathan »

Thank you much for all your suggestions Gerry.
gbin wrote:As I understand you, your strip transects are actually going to be time-limited surveys; otherwise they're really just long, skinny quadrats. (I understand your concern about low herp densities making quadrat sampling ineffective, but you never really know until you try, and it's an easy, low-cost, -tech and -disturbance method that everyone readily understands, so I recommend that you keep it as a back-up, anyway.) To get at the herps living in or just beneath the leaf litter, though, how would a time-limited survey work? Sifting through leaf litter for potentially small organisms is time consuming, with the larger the area being searched of course being the more so. I don't know of any way around that short of trapping.
Yeah, I've seen it called a "belt transect" or other names and it's been used quite often for this kind of survey before. It will be a time-limited and area-limited, primarily visual search. Refugia sites will be investigated (though manipulable refuges are not common in this forest), but I won't be combing through all the leaf litter or doing any habitat-destructive searching. Basically, I'm not trying to reproduce the trap finds but to complement them, so the transect searches are really focused less on the leaf-litter herps and more on the herps that choose exposure.

Different studies have varied the degree to which "quadrat-searching techniques" are used during belt transects. The spectrum goes all the way from visual searches made without touching anything to the full "long skinny quadrat" possibility you mention, with points right in the middle too. This is something I'll continue to reconsider as I plan the study.

My desire is simply to use techniques that both have the highest likelihood of encountering a meaningful number of herps and that can be done in a systematic way such that results are comparable. Quadrats are systematic, but I have no faith that I can get the numbers through that method to make comparisons. At least one paper (Inger 1980) states that South Asian herp densities are the lowest in the world, and every single comparison paper I've seen showed South and Southeast Asian herp densities to lag far behind Central/South American densities. As a result, every South Asian study I've read that used quadrats to compare different habitats either gave up on them during the study, or failed to find enough herps to make meaningful comparisons even after carrying them through all the way to the end. I will indeed have it in hand as a backup option, but that would only be an emergency if I'm not allowed to trap and have nothing else left to complement visual transect searches.


And yeah, on the books thing, we've ferried books and gifts via visitors before, but we don't have any scheduled visitors between now and June coming from the West. We're kind of hard-core on the whole emissions thing and so we reduce our own flights extensively (haven't been outside of south Asia in two years by June) and discourage other people from making quick jaunts out just to see us.

The problem with more expensive shipping options is that when we ship something from State-side we can't actually control who they use India-side, and their liability doesn't even apply either. We bought something from Amazon, with tracking and everything, that never arrived. We told them and they tracked it to the Indian port. They claimed that at that point their tracking and their liability ended. We never got the product and still paid for it.

But I'm still taking your suggestion seriously on the books (more seriously than before, when I was just going to wait to I got to Bangladesh to read my friends' copies), I will continue trying to think of a way to make it happen. The last book you recommended was smaller and quite cheap used, so we might try to ship it and hope for the best. One of the books is kindle-available, so I may be able to buy it and then convert it to pdf (not having a kindle myself). A couple can be shipped within India for less cost than overseas and I may risk it, though they're still expensive for my budget to have such an uncertainty.
Post Reply