Studying Turtles at the Orange Grove Pond

Uploaded by CalStateNorthridge on 11.05.2011

DR. ESPINOZA: This is Biology 512, which is herpetology,
a senior-slash-graduate level class,
and we are doing a population survey of pond turtles.
They've been introduced here by lots of pet enthusiasts,
who probably got tired of their pets.
But it offers an opportunity for my students to understand
something about population biology.
The techniques we're applying are exactly like any professional herpetologist
would to a real population of natural living animals.
The first team is the capturers. We call them the wranglers.
They transfer the turtles once their captured into buckets
for the people that mark them.
BECK: I'm injecting it with a small pit tag, which can be read electronically
so that we can get an individual ID on this.
We're going to measure the mass and the overall size of this turtle,
so that when it's later caught, we can compare it's growth rate over the years.
And then we're going to use these initial taggings
to determine if the same individuals are still in this population
year after year and see how many new ones are being added.
NICHOLAS: This is a bullfrog tadpole.
This is another invasive species that is not native to California.
And the problem with these guys is that they grow to such an enormous size.
Most of our native frogs are about this big as a full grown adult.
So an organism that can be this large as a juvenile
can have an advantage over the native wildlife
and more easily displace them and even devour them.
So especially when it comes to invasive species, best thing to do is just
remove them from the area and give the native wildlife a chance.
DR. ESPINOZA: Looks like we've got probably close to forty, maybe close to fifty now,
and I estimated there's over a hundred here.
BECK: As soon as we're completely done with all of them
that we've caught, we're gonna put them back in.
We wanna make sure that we've gotten every single one of them today.