Winter at the Desert Tortoise Conservation Center
Posted at 3:51 pm January 5, 2010 by Kirsten Dutcher
Spring Mountains, to the west of the DTCC, dusted in a layer of light winter snow in December 2009.
At the San Diego Zoo’s Desert Tortoise Conservation Center (DTCC) it is hard to imagine we have so many tortoises on site because all of them are underground sleeping in burrows.
This winter hibernation, called brumation for tortoises, is actually very important for the health of the desert tortoise, because it allows for substantially reduced metabolic activity and aids in normal growth patterns during the active season by providing a period of little or no growth in the winter. Temperatures can drop below freezing during the winter here, so to protect themselves, tortoises dig natural burrows that are often curved, providing wind and rain breaks.
Volunteer Kelly Garron constructing a berm in front of an artificial tortoise burrow.
Many people think of the desert as a hot, dry place, and for much of the year it is; however, during the winter the average highs are in the 50s while the lows are in the 30s. Chilling, seemingly relentless winds whip through the desert frequently and can exceed speeds of 40 mph. In December 2009, just last month, we saw snow at the DTCC! It didn’t stick, but the Spring Mountains to our west were dusted in a light blanket.
At this time of year we also receive roughly 2 inches (5 centimeters) of rainfall, which is pretty impressive considering that the Las Vegas area averages less than 5 inches (13 centimeters) per year! In 2010, we have had 0.29 inches (0.7 centimeters) of rain so far, but most of our rain usually falls in February (according to National Oceanic and Atmospheric Administration), so we are hopeful winter rains will be plentiful here. The winter rains are vital to the spring bloom, which can be very impressive, and they also support much needed food and water sources for tortoises when they come out of hibernation.
So while we finish berming tortoises in for the winter to keep them safe and protected, we will hope for more rain and a beautiful spring bloom to report!
Kirsten Dutcher is a research associate at the San Diego Zoo’s Desert Tortoise Conservation Center. Read her previous post, Reptile Diversity at Desert Tortoise Conservation Center.
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January 6th, 2010 at 8:25 am
How are the young tortoises doing that were found while digging a few months ago? I have not heard any updates on them in a while and the picture of them were just so cute! I never knew they were so small. I always thought of a tortoise as a much larger animal. I guess everything (except elephants) start of real small though. But a update on the babies and maybe a picture of them would be great! I hope they are ok! One other question, if the parents go into hibernation but the babies were so small… do you all keep them out at that time to make sure they are ok for their first winter? Minds want to know! We all love our babies!
Kirsten responds: The babies are doing great! They are living in their new predator-proof hatchling enclosures that we completed just a few months ago, and they are comfortably hibernating. We anticipate seeing them in early spring when they wake up, and we will be sure to take pictures and post them here on our blog.
Since adult tortoises do not provide protection or care to their young, tortoise hatchlings are on their own as soon as they hatch. The parents of our little hatchlings are now hibernating in adult burrows that are separate from the hatchlings, because we keep all our hatchlings in the predator-proof pens where they can grow up safe and sound.
If you or anyone you know has tortoises, remember that hibernating is an extremely important part of their lives, and this is especially true for tortoise babies – they are healthier as adults if they are allowed to hibernate naturally when they are young, even during their first winter of life!
January 12th, 2010 at 11:08 am
We were recently at the san Diego zoo and wild animal park and always love to be there.
I just now found the site for desert tortoises. Can you give info as to where you are located? We didnt know about this site when we were there.
Also, we have a 4 year old sulcata who weighs almost 90 pounds. She has never hibernated, eats almost every day, and seems healthy. we live in southern florida and the other 91 various turtles we have dont hibernated either. Can you tell us how and why they should? Hope to see your area the next time we are there.
Moderator’s note: The San Diego Zoo’s Desert Tortoise Conservation Center is located in Las Vegas and is not open to the public.
DTCC responds: Not all turtles hibernate, so you may have species that don’t. The best thing you can do is to look up on the Internet or in a book each species that you have and see what their specific needs are. Not all turtles and tortoises have the same food, water, shelter, and hibernation requirements, so you want to make sure each individual has their basic needs met.
I am a bit concerned that your 4-year-old sulcata weighs 90 pounds. Generally sulcata hatchlings weigh less than an ounce when they hatch and it takes 15-20 years for them to reach maturity and approach their full weight of 80-110 pounds. If your sulcata is four years old and weighs 90 pounds, I strongly recommend that you consult with an experienced tortoise veterinarian right away.