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How Old is My Tortoise?
and Other Desert Tortoise Questions

by Michael J. Connor, PhD

Tortoise nesting
The author's desert tortoise nesting
Photograph by Michael J. Connor

How old is my tortoise?

Easily the most common question that I get asked, particularly by new CTTC members as they proudly show me their beloved Methuselah. Unfortunately, unless the tortoise was very small when acquired or has a known date of birth, it is almost impossible to tell its age accurately. Counting "growth rings" around the scutes may be useful in small tortoises. These rings are formed because the scutes (or shields) are a modified form of skin that is continually renewed. The new scute material grows under the old, and being larger shows at the edges of the scute as a "ring". Unlike trees, however, tortoises (especially well nourished captives) don't get a new "growth ring" every year. On the contrary, several "growth rings" may appear in a single season! In bad years, some wild tortoises may not show any growth at all. When a tortoise reaches adult size (at 10-20 years) growth continues, although new scute rings are almost imperceptible. In fact, in a recent attempted study of the age range of wild tortoises at the Desert Tortoise Natural Area one biologist resorted to using an electron microscope to count the minuscule scute layers found in mature animals!

Once a tortoise reaches adulthood its appearance continues to slowly change. The often beautiful scute-sculpturing of the youngster becomes progressively less distinct. The scutes become flattened, take on a dull sheen and eventually become a more uniform gray color. In extreme old age the scutes may appear sunken in, as calcium becomes depleted from the bony shell that lies underneath them.

My grandmother gave us her desert tortoise that she has had since 1956. Is it illegal for us to keep it? How should we look after it?

Because desert tortoises are endangered and are protected by state and federal laws, many people think that their ownership has been outlawed. This is simply not true. Tortoises can be possessed in the State of California providing that they were acquired legally (in this example the animal is a long term captive) and that a permit to possess a Gopherus tortoise is obtained. Permit forms can be obtained by calling the secretary of the CTTC Chapter closest to you.

As far as looking after this tortoise is concerned, I recommend two things. First, if possible consult your grandmother. Anyone who has successfully maintained a tortoise for nearly 40 years has obviously been doing the right thing for that particular animal! Second, contact your nearest CTTC Chapter for a desert tortoise care-sheet and other information. Even better, join CTTC, go along to your local meeting and talk to other experienced tortoise folk.

How can I get a desert tortoise?

Desert tortoises are listed as threatened species by both Federal and California State governments. It is therefore illegal for the general public to take or harm wild desert tortoises. Although desert tortoises are suffering desperately in the wild and their populations are collapsing, the desert tortoise is unusual for an endangered animal in that at the present time, tens of thousands of desert tortoises are held in captivity, mainly in southern California. Some are long term pets, many are captive bred offspring of captive parents. These animals cannot be returned to the wild. Where they came from is unknown, and even if their origin was known it is doubtful that after a long spell in captivity they would survive the rigors of the wild without intensive rehabilitation. It is also illegal to release desert tortoises.

California Department of Fish and Game allows organizations like CTTC to place homeless captive desert tortoises in new homes. Each year, CTTC adoption programs place several hundred adult tortoises that have been found lost or abandoned on city streets, or who's owners have been forced by circumstances to give up their beloved pets. CTTC also places many of the hatchlings bred by Club members.

To obtain a tortoise through the adoption program, contact your Chapter's adoption chair for an application form. Remember, CTTC will only place tortoises in suitable homes.

Why do I have to wait so long to adopt a tortoise?

Fortunately, for homeless tortoises at least, there are more people interested in adoption than there are tortoises that enter the adoption programs. Would-be adopters are therefore likely to find themselves placed on a waiting list. When a tortoise comes in for adoption, the adoption committee members, using information provided on the adoption form, place it in the most suitable home from the names on the list.

The Club has no control over when tortoises are turned in, but because they stress easily, efforts are made to place tortoises as soon as possible after receipt. Would-be adopters need to be prepared for this, and should be ready to provide suitable accommodations in advance. It is very frustrating for our hard-working adoption committee members to have to waste time waiting for phone calls to be returned, or worse, to spend time calling numbers that are no longer in service. Make sure that your application is up-to-date.

For various reasons, there is a greater demand for adult female tortoises than adult males. Hatchlings are more easily obtained than adults, but they require more elaborate care than many would-be tortoise owners care to give.

Each Chapter of CTTC operates an adoption program in its local area. Tortoises that are turned into a Chapter are normally adopted out to someone nearby because the local climate and environment are more likely to be similar to those the animal is accustomed to and has survived in over the years. Desert tortoises, as their name suggests, survive better in the warmer and drier inland areas within or close to their natural range. Fewer tortoises are found closer to the ocean, so fewer are turned in for adoption to Chapters located further away from the desert. For this reason, if you live in an area with few captive tortoises you may have to wait a very long time.

How can I tell when my female will lay her eggs?

Judging from the number of calls I get from excited tortoise keepers who have found a hatchling or two unexpectedly emerging from the ground this is not always easy! Some tortoise owners are lucky, their tortoise predictably lays at the same time each year.

I can tell when my female is getting ready to lay from her behavior. Normally, in the late afternoon she grazes on grass and then at about 5:00 pm moves over to near the garage where she sleeps. A week or two before laying she switches to hanging around a particular spot in the yard she has chosen until dusk, and only then does she return to her sleeping quarters. Once she seems happy with the chosen location she will sniff the ground, and make trial excavations. She never seems serious about nesting when making these trial nests, since she usually waits until fairly late in the day to start digging them. She spends a few minutes clearing the area with her front legs before excavating 1 inch deep holes with her back legs. She then retires for the night. After several days of this (this year I ended up with 5 large holes in my lawn) she will finally construct the real nest. I know when she is serious because she starts excavating earlier in the afternoon, by about 4:00 p.m. at the latest. It takes her 3-4 hours to construct, lay and fill in the nest. The next day she returns to her old routine.

Apart from watching its behavior, it is also possible to "palpate" your tortoise for eggs. This requires that you carefully press a finger into the body cavity on each side of the tortoise just in front of the tortoise's back legs. By gently rocking the tortoise from side to side you can feel mature eggs. However, palpation takes great care and some experience to accomplish successfully.

Why doesn't CTTC run a tortoise dating service? My tortoise is lonely and needs a mate.

The easiest way to kill your tortoise is to introduce it to another animal. Judging by the number of runny-nosed tortoises turned into the adoption program, upper respiratory tract disease affects and is carried by a large number of captive tortoises. Other problems such as intestinal parasites are prevalent. There is no way that CTTC could run such a service with out serious risk of making this problem worse.

That being said, producing hatchlings is one of the most rewarding aspects of keeping tortoises. If you do want to breed you should either adopt an animal of the opposite sex or reach an agreement with someone who has a single healthy tortoise that has been kept well away from other tortoises. Before introducing them, get both animals checked out by an experienced veterinarian.

If you obtain a partner for your tortoise through the adoption program remember to keep it in strict quarantine until you know that it is healthy. I strongly recommend not introducing your treasured tortoise to a new mate until you have kept and observed the newcomer for at least 1 year.

As far as being lonely is concerned, my experience has been that many captive tortoises suffer from the opposite problem. They are stressed out because they are forced to live in close in proximity to other tortoises. In the average backyard choice grazing, sunbathing, and burrowing sites, and opportunities for a tortoise to be alone are very limited. Wild desert tortoises almost never share burrows! Loneliness is a preoccupation of the (human) keeper, not the tortoise.

How can I tell when my tortoise is sick?

Like most reptiles, sick tortoises may take a long time to exhibit severe signs of illness. Therefore, it is very important that you take the time to carefully examine your tortoise regularly and get to know its behavior so that any problems can be detected early on.

Weigh it periodically to determine if it is gaining or at least maintaining its weight. Check its shell and skin for unusual lesions. Watch your tortoise, and get to know its routine. Changes in its eating and drinking habits, or even the way it walks around may be clues to the onset of illness. Check the tortoise's droppings. These should be firm, solid and well formed. Diarrhea is a common symptom of an incorrect diet or of an intestinal problem such as an excessive worm load. Constipation may also occur. Tortoises exhibiting severe straining or difficulty in passing feces need prompt medical treatment. Like birds, tortoises excrete nitrogenous waste derived from the breakdown of dietary protein as uric acid derivatives. The uric acid is voided in the urine, and is visible as white crystals or a white suspension. This may be discolored in sick animals. Runny noses or heavy wheezing are common symptoms of a variety of illnesses. Consult a veterinarian immediately should these symptoms appear.

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Originally published in the Tortuga Gazette 29(7): 1-3, July 1993

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