Research on Green iguana, Iguana iguana
In 1988 I started my
undergraduate research by studying the diet of green iguanas. 
In the interest of studying their diet without hurting
or killing the animals, I caught the animals in
the field, climbing the trees where they lived or chasing them down when they
were on the ground. I developed a method to studying their diet by performing a
stomach wash to the animals and obtained the
information of what they have eaten lately. Luckily the iguanas do not
chew the leaves or flowers which allowed me to identify diet to the
species level in most cases. My work was followed by one of my colleagues
(Cesar Molina). Cesar and I caught a total of 365 animals of all sizes and
identified 125 different items in the diet.
I
continued studying iguanas for five more years. I studied population dynamics, sex differences, tick infestations, predation,
antipredator social behavior, 
nesting success, and farming . My experience with iguanas lead me
to fall in love for them and for all the
secrets that they have on hold for us to uncover in the future. For
example one of the the most interesting results of our research is the finding
that neonate iguanas have extremely complicated defensive mechanisms to avoid
predation involving group-based strategies that may result in the voluntary
sacrifice of some individuals for the benefit their sibblings. In
particular some males might attrack toward themselves the attention of
predators buying, this way, their sisters the possibility to survive and
reproduce. Kin selection as well as the complicated dynamics of
differntial survival, mating and reproduction of males and females seem to be
involved in the explanation of this phenomenon; but the last words is still far
from being said (click here to see the whole article).
I look forward have a little time to retake this line of research in the
future. Due to academic commitments most of this remains largely
unpublished. Some of the articles that I have managed to publish are
listed bellow, the remaining are in the proccess of being published.
Some of the articles that we have
published so far on iguana's biology are listed and linked bellow
-Rivas, J. A. and Levin, L. Sex differential
antipredator behavior in juvenile green iguanas, Iguana iguana: evidences for
fraternal care. In: Evolution Behavioral Ecology and Conservation of
Iguanas. University of California Press.