Uncategorized

About Author: Jeanette Perry

Posts by Jeanette Perry

4

White Christmas for Juvenile Desert Tortoises

A tortoise burrow can be seen the morning after a nightfall of light snow. desert.

A tortoise burrow can be seen the morning after a nightfall of light snow. desert.

Juvenile desert tortoises released in September 2012 at the Nevada National Security Site are making their way through their first winter in the wild. The tortoises were snug tight in their burrows over the holidays when temperatures dropped below freezing and a light snow fell.

As ectotherms (cold-blooded animals), desert tortoises must utilize their surroundings to regulate their body temperature since they can’t warm their bodies on their own. Only a few inches of soil are enough to buffer air temperatures to allow the tortoises to hibernate through the winter without freezing. In a few more months, when the air temperatures begin to rise here in the desert, all of our translocated tortoises should emerge to heat themselves in the sun.

Jeanette Perry is a research assistant at San Diego Zoo Global’s Desert Tortoise Conservation Center in Las Vegas, Nevada. Read her previous post, Wandering Males, Jealous Boyfriends.

8

Wandering Males, Jealous Boyfriends

Jeanette removes a transmitter from one of the released desert tortoises.

We’re currently at the tail end of one of our desert tortoise translocation projects. It’s finally time to say goodbye to the desert tortoises we have been tracking for the past year and a half, and over the past month or so we’ve begun the task of removing their transmitters. However, this is easier said than done. This project happened to end during the mating season, a time when males move long distances in search of females. One of our males went missing for five weeks and was found almost three miles from his old burrow!

Before we remove the transmitters, we do a final health assessment. We noticed damage to the underside of the carapace (the top shell) on many males. They are known to fight other males utilizing their gular horns to attempt to flip their opponent onto their back. Some male tortoises are bolder than others, and we came across a very bold resident male searching for a female one sunny morning. As my coworker, Jason Rose, and I approached a burrow that female tortoise #619 was occupying, we heard movement inside the burrow. Assuming it was the female we were tracking, we checked the burrow and saw a male tortoise charging at us! He came straight out of the burrow and blocked its entrance, trying to keep us away from his mate. His chin glands were enlarged, and he looked mad!

Here is tortoise #619′s very ardent and determined suitor.

Jason put some gloves on and moved him 50 meters (165 feet) from the burrow so we could get to the female. While waiting for the female to come out of the burrow, the male snuck up behind us and attempted to re-enter the burrow. This time we moved him 100 meters (328 feet) from the burrow to give us some time with the female. Moments later, the male returned and charged Jason. Knowing the female was not going to exit the burrow with the aggressive male in the area, we packed up and allowed the male to re-enter the burrow. He positioned himself facing toward us, in front of the female. Claiming defeat to the jealous boyfriend, Jason and I left the site.

Jeanette Perry is a research assistant at San Diego Zoo Global’s Desert Tortoise Conservation Center in Las Vegas, Nevada.