Reptile & Amphibian Forums

I've noticed that the blue color of wild western swifts in our local area changes dramatically dependent upon the location they are found in. Furthermore, some of the wc animals that were really blue years ago and are now running wild on the walls around my yard aren't as blue as they used to be. They seem to be prospering, in good health and breeding successfully, so I have to assume either their diet has changed, or something in their prey's diet has changed that is effecting their blue colors.

With that in mind, does anyone know of any research or scientific information on what dietary/environmental influences may be involved in the colors of these lizards, or generally what is in a lizard's diet that can enhance their natural blue colors?

Thanks,
Roger

Sceloporus sp. have brighter colors when looking for mates. Also males are more colorful then females outside of the breeding season. So your observation could have several possible implications. Consider the following:

1. You are seeing more females then males. The could be the result of pestesides or other polution. This very same effect has been noted in human populations in some locations.

2. you are observing shorter breeding seasons. Temperature related?

3. Natural selection, is there a new predator selecting the more colorful lizards? Human collection?

I would eliminate food as a possible cause given that captive bred Sceloporus sp. are just as colorful as wild caught given a diet of only crickets.