Thank you for the input!
I thought April and early May might be a little too cold for the target species to be on the move.
No problem. No cost, and possibly equal value! Ha ha ha.
Re: target species, perhaps I fixated too much on geckos, Gilas and torts. But if you think they need it very warm, you are in for a surprise. A dead-calm sunny morning can have an air temp of say 62-65F, but the substrates (or a basking "object") can easily and quickly warm up to the high 80s/low 90s. Perfect operating range with little danger from overheating. Whereas air temps above the low 80s, with full-roasting sun, will quickly generate full-sun substrate temps of >>105, which is not much good to you. You'll be searching only in the shade, which is a smaller area but much of which is totally visually obscured by vegetation. Or actually underground...buh-bye.
Think some more on elevations and the lat/long distributions of your "real " target species. Maybe it's just those 3 species you mentioned, maybe you also wanna see more like chucks, desert iggys, Phrynos, I dunno. Whatever, that's all you man. My point is, elevations on the CO River are like 400-500', Phoenix is something like 1100', Tucson is ~2400', and the valley
floors in SE AZ are ~4500'. That right there is "montane" to an easterner. A useful rule of thumb is you lose/gain about 3 degrees F for every 1000' you go up/down. So if the daytime high in Tucson is gonna be 85, down in Parker or Yuma it's gonna be probably about 90 or a little more. And Wilcox or Sierra Vista might be in the high 70s. Don't get all hung up on that 3 degree number, it's often a little - occasionally a lot - off, but it's still a useful rule of thumb. It's usually pretty close.
Also consider seasonal climatic norms that drive seasonal herp activity patterns. If you want to field-herp the river corridor for diurnal lizards, you can do well in mid-late March (
if there's no cold wind from a dry cold front). Wait for perhaps late April or early May if you wanna do the same thing in Tucson. Most of the river's (paltry) precip comes in the winter, whereas at least half of SE AZ's precip comes in the summer. Most desert wildlife's life cycle is tied to the dependable growing season - when it's warm and there's some soil moisture.
- In the low western deserts, that is much more in the spring (March-May), much less summer (June-August).
- In SE, there's a spring window and a monsoon window. In between (always June, plus often/usually late May and early July) there's a hot dry season that's "less awesome" than either spring or monsoon. "Less awesome" can range from full-suck to meh. How lucky are you? Ha ha ha. Got a lot of time and money to gamble?
We are thinking about road cruising and hiking in the mornings until around noon.
- Morning walks are spot-on. Personally, for what (I think...) you're after, forget the car. Or leave it until after your walk, and maybe just use it to spot baskers for an hour or so before lunch, on the bigger roadside rocks. Walking a desert morning will delight you in
so many ways, don't give much of that away to the car, for God's sake. Are you really coming from NYC? Jesus,
get outside - afoot outside, not in the car outside - and absorb all the glory that is the desert in spring! Sights, smells, sounds, all of it.
- Work the washes, cut banks of which are good where there's holes in the bank and such. Look in and around the holes but don't stick your hand in them.
Make a habit of frequently switching your gaze from right around where you're stepping, slowly out to as far as you can see up to the next bend in the wash, and then back to your foreground on a different path. Periodically, stop moving completely and take a good slow long hard look all around you, at all distances, in full sun, in full bank- or boulder-shadow, in dappled shade under bushes. You're gonna probably see some big, medium, and small rattlesnakes both coiled up and stretched out, possibly uncomfortably close to your feet. Atrox are pretty camo, and really pretty mellow until or unless you scare them - so don't count on a buzz to keep yourself un-bit. Also FWIW, most of my on-foot Gila sightings are of them pretty far away from me, just motoring around a wash bottom doing their thing. It's a rush, of which I will never, ever tire. Don't try to touch them, it's illegal and dumb - they will
bite the hell out of you, given a chance.
- Take a temp gun
and use it to figure out what objects to flip and which to skip, as well as what the full-sun substrate temps are. You can flip up geckos real easy, as long as it hasn't all dried out yet. Usually if it's still cool nights and nice days, smaller and lighter objects (a bonus to your back!) will have better temps (say 68-80F) underneath. Garbage, woody stuff, and little rocks. Carpet is the bomb if you can find any! Watch out for scorpions and black widows,
leather gloves are your friend.
Don't forget to buy a license for herping. $20/day, get it online ahead of time, so as to not waste valuable vacation time indoors waiting in line. Chapstick and sunscreen - just sayin'.
Good hunting, be careful, let us know how you did.