How do chams know what constitutes acceptable prey in the territories new for them?


Chameleons evolved approx. 100 millions of years ago in eastern Africa. During their long evolution, they naturally spread to neighboring territories and conquered parts of Southern and central Europe, east over Asia to India and China and to Madagascar. Due to climatic changes, they lost parts if the northern territories later on. They are the true old-world lizard family.

Thanks to the explosive development of herpetoculture at the end of 20th century until now, 2 chameleon species are now relatively well established in the captivity.

The vast majority of the food of captive chameleons consists of farmed captive insects.

However, people try with good right and for the benefit of the chameleons to utilize also local resources of food, local insects and invertebrates and even vertebrates (geckos, anolis, incidentally birds).

In paralell, feral populations based on escapees or intentionally introduced chameleons to the wild of not only USA, but also Taiwan and Canary islands are facing all new food items, which they have never met during their evolution.

So, how they know what to eat and what not?

They do not know.

They have their evolutionary experience in their homecountry that formed by the evolution the brutal darwinistic way:

Those who ate good food were stronger and more likely to forward their genes to next generations.

Those who ate wrong food died or were weaker and less likely to forward their genes…

So, we see now that if they eat predominantly flying insects and pollinators like flies, bees, wasps and small beetles, this is what is good for them. They do not eat adult big locusts at all. Because this is what made them to survive till now. (In each species it can be a bit different and as opportunistic feeders, they eat what is the local choice, even seasonally - but selectively, due to the mechanism explained in a simplified way above).

In captivity they have no clue what we give them, so they try.

So, WE must be the knowledgeable ones and regulate for them. Eg not feed lubbers and American firebugs as they are poisonous but they can misidentify them with something they have eaten in Madagascar, where there was no issue with it.

If you fees with local insects, get familiarized with the following constraints:

TOXICITY - learn about local poisonous and venomous potential feeders and avoid them. The e examples are: hairy caterpillars, ladybugs, fireflies and their larvae, lubbers, ants, spiders, some beetles, too big hymenopterans like hornets. Bees and wasps are usually fine.

POLLUTION - feed insects only which are from areas evidently not treated with pesticides or polluted by agricultural, industrial or urban pollution. In case of doubt either abscond or use the one-day-rule: what does bot die within one day, is very likely safe to feed and not poisoned.

CONSERVATION - do never fees with local fauna which is protected by law or otherwise endangered. In case of bees beware the global decline of them and feed only drones or parts of the beehive which are to be dismissed due to regulations of the hive population (like ild bees, drones slots etc) or to some bee disease. Alternatively breed your own bees.

Author: Petr Nečas