at Mon Aug 15 14:31:40 2011 [ Report Abuse ] [ Email Message ] [ Show All Posts by RichardFHoyer ]
I don't frequent the herp forum but once in awhile so didn't see you message until this morning. Now this is just a guess----so don't take my 'opinion' as if it were fact.
It is my view that a late melting snow pack might only marginally delay courtship, coupling, and onset of gestation but should not affect the overall reproductive output of a boa population. At higher elevations, the species likely occurs where optimal exposure to sunny conditions (south facing aspects), produces preferred temperatures. Even if the snow pack melts late, there should be openings where the species can carry on its life activities including mating. Early in the year, both here in Oregon and my son in Utah, have found boas thermoregulating near or next to snow from February into early May.
What might reduce overall production of neonates by a population at any elevation, but particularly at higher elevations, is unsuitable weather / temperature conditions during the gestation period. For instance, an early onset of periodic winter type storms, accompanying overcast conditions, and significantly cooler temperatures in late August and thereafter would likely have a negative effect.
In Calif., the species is found all along the coastal regions from San Luis Obispo Co. on north into southern Oregon. However, the species does not occur along most of the
Oregon and Washington coasts because there likely doesn't occur the minimum number of days with sunshine and suitable temperatures necessary for the species to successfully complete gestation. The same would apply at higher elevations.
As for the DOR, the coloration of the boa in the photo is medium brown and thus not typical of neonates which normally are a pinkish, orangish, or flesh color but just a bit darker on the dorsal surface. Parturition in the wild at lower elevations generally begins from late August and thereafter. I suggest it is far too early for boas to have produced a litter at this time of year at higher elevations.
May I ask where you found the DOR at 8000 ft. Too bad I wasn't there as I would have taken a tissue sample. In the works is another research project on the species that would use both molecular and nuclear DNA testing from samples throughout the species' distribution.
Richard F. Hoyer
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