I
do much of my work near Pinecrest lake in the Sierra Nevada Mountains just north
of Yosemite National Park.
This beautiful view shows the South fork of the Stanislaus river flowing past
my study area. I
do much of my work near Pinecrest lake in the Sierra Nevada Mountains just north
of Yosemite National Park.
This beautiful view shows the South fork of the Stanislaus river flowing past
my study area.
Much of the work I do up on the mountain is focused on Sceloporus lizards. Sceloporus lizards (affectionately known as "Scelops") are only about 15-20 cm. long, but don't let the small stature fool you. Their size beguiles their aggressive nature. Scelops are very territorial and are often seen displaying and fighting for territory and females. Males perform push up displays as a way to signal to other males and to attract females.
Check out some of the other wildlife at Pinecrest Lake
Particulary interesting are the potential ways in which body coloration determines a male's mating success. Females are thought to choose among different males based on the brightness of a males throat and his particular ways of courting the female. Males perform push up and headbob displays to try and entice females to mate with them. You can watch a typical male courthsip display in a movie.
Two different species of Sceloporus lizard live together near Pinecrest lake. The focus of my study is on S. occidentalis, which comes in two subspecies flavors. S.o.occidentalis and S.o. taylori may be hybridizing at Pinecrest lake. Pictured below are two male morphs which may represent different sub-specific groups.
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S.o occidentalis are somewhat smaller than S.o. taylori and live in the northern regions of the Sierras. You can see that the blue area is limited to their sides while their throats tend to be a rather dark. |  |
We also see male morphs that are quite a bit larger and live to the south of S.o. occidentalis. They have extremely bright blue throats and bellies as you can see in this picture. They use these colors to attract mates and keep other males at bay. |
One aspect of our study, determining how females may descriminate between males of the two different subspecies, is just now getting underway. Because this part of our project is just taking off, we'll be expanding our website and our study area as we learn more about this complex story. This map shows the known hybrid zones between sub-species of Sceloporus occidentalis lizards in California.
While much has been done to learn about the life histories of these lizards, there is still much to explore. We are currently studying the ecological and behavioural characteristics of these lizards as well as those of another lizard, Uta Stansburiana. In order to best understand the animals, it is necessary for us to spend time living and interacting with the lizards. As you can imagine, the life of a field biologis is not your typical day in the office.
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