Bogotá's mountains are home of four species of lizards representatives of three different families. These lizards have been adapted to these "páramos" ecosystems which can extend up to 3200 meters above sea level and reach very cold temperatures. These lizards coexist in these environments by using different microhabitat levels such as under flat rocks, mosses, low shrubs, and trees.
Lizards in this community remain poorly studied and most of its natural history remains unknown. While working in Andes University herpetology collections, my colleague and friend Juan Salvador Mendoza and I dissected the stomach contents of several Dumérils Whorltail Iguana (Stenocercus trachycephalus). From our sample of lizards we observed bettles (Coleopetrans), ants and vespids (Hymenopterans), and crickets and grasshoppers (Orthopterans) were the most common prey item in their diet. Additionally we found its diet was composed of at least eight different insect orders. This is presumably the first attempt to quantify this species diet! |
Florida is currently classified as one of the regions with the highest number of introduced species in the world, especially herpetofauna. South Florida's tropical climate make it a hotspot for reptile invasions. Currently, at least 48 and 5 species of lizards and snakes respectively are established in the state! However, most of their ecological impacts and interactions remain unstudied.
As a master student advised by Dr. Steve Johnson, I evaluated the interaction between Brown Anoles (Anolis sagrei) and the Northern Curly-tailed Lizard (Leiocephalus carinatus). These two species are probably the most abundant species in South Florida reaching densities of at least 1 individual per square meter! Northern Curly-tailed Lizards (once called the T-Rex of the ground) enjoy bullying Brown Anoles by chasing them on parking lots and eating their babies.
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For this project, I chase and capture both species of lizards on eight shopping plazas in South Florida. I removed Northern Curly-tailed Lizards on 4 of these plazas to test the effects this predator can have on Brown Anoles. Therefore, I compared these plazas against similar ones where I did not conduct these removals. To evaluate Brown Anoles population, I measured and marked them using visible implant elastomers.
After a six-month period of being called "The Lizard Lady" by the locals, I was able to detect population and behavioral differences on Brown Anoles between the two type of sites. In absence of their tyrant predator, Brown Anoles had higher survival probability and consequently greater abundance. Interestingly, Brown Anoles shifted to lower perches a few months later after their predator was removed. These results suggest Northern Curly-tailed Lizard exert predator regulator role on Brown Anole urban populations.
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Frogs as all other amphibians, have a highly permeable and scaleless skin which is very vulnerable to water loss. Frogs must keep a moist skin to maintain a nice flow of oxygen, after all, frogs breathe through their skin! However, on any given day of a frog's life, environmental conditions can make it pretty tough for them. As frogs were moving from water to land ecosystems, they had behavioral and internal and external body modifications. These changes allowed them to survive in different ecosystems including cities and deserts!
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