An Amateur's Account of Breeding Asian Tortoises

Yvonne G

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Way back in 1996 I had an accidental mating between a very young male Mep and an aged Mee. With the help of my friend Jim Buskirk, I wrote the following article:

AN AMATEUR’S ACCOUNT OF

BREEDING ASIAN TORTOISES

(Manouria emys emys/Manouria emys phayrei)

by Yvonne M. Gomez and James R. Buskirk

(originally written in 1997 concerning the 1996 breeding season)


INTRODUCTION

The largest species of land tortoise found on the Asian continent is the Asian Giant or Mountain Tortoise, Manouria emys – Schlegel and Muller, 1844. Both an eastern and western race are recognized, M.e.emys and M.e.pahyrei (Blyth, 1853). Both subspecies, the larger and darker western as well as the smaller, more brownish eastern, are available in the pet trade and their requirements in captivity seem identical. Other than by maximum size (Obst – 1983, Blitz – 1989, Cox et al. 1998), these subspecies are differentiated by the blackish overall color of the former (Black Asian Giant Tortoise, M.e.p.) and the more yellowish-brown or brownish complexion of the nominate race (Brown Asian Giant Tortoise, M.e.e.). However, the most reliable difference between the two is the unique position of the pectoral scutes of M.e.e., which do not meet in the plastron midline as in other tortoises. In fact, they rather resemble oversized axillary scutes. The pectoral scutes of M.e.p. may taper narrowly, but do meet at the midline as do the other plastron scutes. Large, pointed thigh spurs are responsible for giving this tortoise the vernacular name “six-legged tortoise” and are usually larger and more numerous in M.e.e. For the sake of simplicity, in referring to either or both subspecies of Manouria emys, we shall simply call them M.e.e and M.e.p. from now on, and “I” refers to the senior author, unless otherwise indicated.

Manouria emys occurs from eastern India (Assam) and southeastern Bangladesh through much of Burma and Thailand to the Malayan Peninsula, and on the large islands of Sumatra and Borneo (Iverson, 1992, Cox et al. 1998). The tortoise is now very rare or extinct in much of its former range. The extent of natural intergradation between both subspecies is not known, and it was not my intention to cause the two sub species to interbreed. To tell the truth, I figured the male was too young. It is my opinion that breeding between the subspecies probably occurs in the wild where the territories overlap. I have one pair of Carolina triunguis. They are obviously three toed box turtles, light horn color, three toes on the back feet. But almost every baby I have raised from this pair ends up looking like Ornate box lturtles, with four toes on the back feet, and ornate markings top and bottom shells. These were purchased about fifteen years ago from a pet shop in a large shipment of box turtles obviously wild caught. Only thing I can figure is that one of them has an ornate parent.

I am trying to find a male M.e.e. and if I do, I’ll separate the different sub species, but until then…


The Tortoises

Because my friend took a job out of town and now lives in an apartment, I am keeping his large tortoises until he is able to take them. The collection consists of:

“the male” – M.e.p. - wild-caught in 1989, at which time it weighed 3kg; currently 43cm straight-line carapace length (CL), weight 16kg

“female A” – M.e.p. – captive bred in 1985, CL 48 cm, weight 21 kg;

“female B” – M.e.p. – probably wild caught, formerly in another collection until given to the senior author in September, 1996; CL 51 cm, weight 25 kg;

“female C” – M.e.e. – probably wild caught, a prior long term captive, CL 37 cm, weight 13 kg. Although the smallest of the group, she seems to be fully grown.


Housing

The tortoises are kept outside, in a pen that measures about 40’ x 50’ and is planted in Bermuda and Fescue. There are four trees in the pen, Mimosa, Modesto Ash, California Pepper and Fruitless Mulberry. These are full grown trees, so there is not much full sun, only patches here and there. I have constructed lines of fence inside the pen that don’t go anywhere, just to provide a visual barrier, so when they wake up in the morning and look out the door, they can’t see their whole world. Along one side of the pen I have put up a “Quonset hut” type structure made out of PVC pipe (bent in a hut shape) that is about 20’ long and 10’ wide. Shade cloth is draped over the hut, and misting pipe and emitters are attached to the underside of the PVC for a rain forest effect.

Their shelter consists of cement building blocks (cinder blocks) and measures about 4’ long, 4’ wide and 3’ deep. Plywood covered with roll roofing tops the structure, hinged for opening to clean and inspect. This is NOT large enough for this many tortoises, I only include the information here so that you can get the big picture. When all four tortoises are in their house at night there is not much floor space left over. The doorway is covered with vinyl strip door to keep out the wind, but lets the tortoises move in and out freely.



Breeding

Last summer, 1996, the male decided to try out his breeding skills and I saw him practicing at various times throughout the season. The females didn’t pay any attention to him, going about their business of marching and eating, treating him like a pesky fly.

This year, 1997, he became a little more aggressive with his advances, biting and clawing the females, sometimes inflicting minor scrapes and scratches on their front legs and eyelids. That got their attention, but I still didn’t think that real copulation was being accomplished. When I tried to get close to look they would stop and move apart. What I was able to see and hear was only that he was mounted on the female, making a hopping movement at about once every five or six seconds, and he emitted a low moaning sound to go along with the hop. (This is quite a bit slower than what I have observed in the Goperus Agazzisi in my collection.)

In early June, 1997, female A and female B started moving twigs and leaf litter around. They kind of go into “la-la land”, becoming oblivious to their surroundings and anyone in it. I provided a huge pile of leaves and twigs for them to use. They would go up to the pile and fling an armful over their backs with first one front foot and then the other. After the felt they had enough out behind them, they would start pushing the leaves with first one back foot and then the other. They continued in this manner several hours each day. They never actually built a nest mound, but moved the litter around the pen for about a week. After that, they both dribbled out their eggs one at a time for about two weeks. These eggs were incubated, but were not viable.

I should interject here that I took Female A to the vet when she first started dribbling out eggs and had her x-rayed to see how many eggs she had (25), and to get her a shot of oxytocin to see if we could get all the eggs out at once. Back at home she continued dribbling out eggs until all 25 of them were expelled in about two weeks. I have since learned that oxytocin doesn’t work on the Manouria;;/'.l. tortoises.

In July, female C started pushing and throwing leaf litter towards the concrete block shelter. She worked about two weeks building a large nest mound inside the shelter, sharing it each night with the other three tortoises. On July 25th, she disappeared inside of the mound. I checked the shelter periodically throughout the day, and after my evening chores found her laying on top of the pile with all four legs spread out as if to encompass the whole pile of litter. I knelt down and moved the vinyl strips aside and she flew off of the pile at me with her mouth agape. For my protection, I put her in a different pen and gently started digging through the leaves. She had laid 30 eggs in a small indentation at the bottom of the pile. the egg on the bottom was broken and I left it there for its scent. I removed the remaining 29 eggs and put “mom” back in her pen. she protected the mound for three days against all comers. During this time, female B was interested in what female C was doing and kept trying to share the mound with her. Prior to egg laying, female C just ignored her, but after the eggs were laid, no one was allowed near the mound. This was a difficult guarding task because the mound took up almost the whole inside of the shelter. It was about three feet square and the base and rose about 2 ½’.


Incubation and Hatching

The eggs looked exactly like Ping-Pong balls with a small dent in the top. Same size and shape as a Ping-Pong ball. I didn’t weigh any of them, but they felt heavy for their size. The literature that I have read about these eggs suggests that the dent would go away as the baby grew, but the dent in these eggs stayed the whole incubation period. I washed the eggs in tepid water and set them on moist perlite, which had been spread about an inch thick on the bottom of my Little Giant Bird Egg Brooder. The temperature was set at 83 degrees. About once a week I would look into the incubator to be sure it was remaining moist, but otherwise I left it alone. If there was no condensation on the window of the incubator it was too dry, so I would fill a spray bottle with warm water and spray lightly over the top of all the eggs. This was strictly a “by-the-seat-of-your-pants” method of checking the humidity, and it worked, but next time I’ll invest in an hygrometer to better assess the chamber’s humidity.

During this time I sold my house and moved to a different one. This was a “fixer-upper” and I was going to get new carpeting, etc. The previous owner warned me of a problem with bugs, so before I had the new carpeting installed, I pulled up all of the old stuff and tossed it, and really scrubbed the concrete floor good. I sprayed bug killer (Ortho Home Defense) on the floor and baseboards. After this dried I placed the incubator on the floor of the living room, in a quiet corner while I finished moving and painting. I promptly forgot about its existence.

One day in October, I think it was the third, I saw the incubator sitting there and said, “Oh my gosh!!!” I was horrified to see a swarm of tiny grease ants. These tiny ants are so small that you can barely see a single ant by itself. Fatal encounters with these tiny red ants elsewhere in California have been documented (Lemm, 1997).

What I found, some 70 days after starting incubation was two eggs had been covered with ants and the babies were eaten and dead. Several more eggs had tiny ant holes in them. I carefully broke open a small hole in each of the “ant hole eggs” and flushed the egg out with warmish water, holding it under the faucet until no more ants were washed out. I cleaned out the incubator, tossing the perlite, and set the eggs back in the incubator, just on the bare shelf. I covered the hole I had made in the five eggs with a moist paper towel. This time I put the incubator on the kitchen counter where I could keep my eye on it.

The yolk sac on the two dead babies was very large, almost as large as the baby itself, so I knew that the other babies were not quite ready to hatch.

After about two weeks all of the eggs had hatched except six, which proved to be clear. Three of the hatchlings were very tiny and didn’t live more than one day. The babies in the eggs that I had flushed with water were fine. You could see a slight discoloration on their heads and scutes where the ants had started eating a layer of skin and shell.


Care of the Hatchlings



The 18 hatchlings are almost two months old as of this writing and all except one are doing fine. The one looks like that picture you always see of the baby box turtle with his shell curled up on the edges that has a calcium problem. This baby hatched out of the egg this way. He doesn’t seem to be getting any more “normal” looking, but he eats well. I soak him every so often in vitamin/calcium water. At the front of his carapace one growth line between scutes was very deep, so you couldn’t see the bottom, but after several months of vitamin E therapy the spot is almost level with the rest of his carapace.

These hatchlings are kept in a glass terrarium with moist orchid bark as the substrate. I had been told that orchid bark is the cleanest, purest product you could find for substrate and it doesn’t cause impaction if ingested. I keep a shallow tray of water in the enclosure. Every morning before I feed them, I mist the enclosure with water. This is their wake-up call and it brings them out looking for food. I use peat flower pots cut in half lengthwise as hide shelters for the hatchlings. I have most of the top of the aquarium covered to keep in the moisture. The light is a “grow light” used for plants, and about once a week I take them out in the yard for some sun. When the weather warms up I will build them a screen covered pen so they can stay outside all the time. The temperature under the light gets quite hot, sometimes about 100 degrees, but the babies can get away from that spot. I never see them basking under the light like the desert type tortoises do. There is an “under-the-tank” heating pad stuck to the bottom of the aquarium under the hide area. Under the peat pots, where the heat pad is, the temperature is maintained at about 85 degrees. If it gets too hot under there, I just add a layer of orchid bark. If it’s not hot enough, I scrape a layer away.

The food I use consists of different vegetables chopped small: endive, romaine, mustard greens, radish greens, kale, squashes, carrots, rose petals, hibiscus, etc. Occasionally I offer them fruit and hard boiled egg (shell and all). They are little eating machines!

When I turn the babies over, six of them have the scute pattern arrangement of the M.e.e. and the rest of them look like the M.e.p. The mother’s pectoral scute is very small, hardly reaching under her plastron at all. The pectoral scutes of the six babies resembling the M.e.e. are quite a bit larger, but still don’t meet in the center.

July, 1998 note: All of the baby Manouria in this article were subsequently sold except five, four which I still have in my possession. They are nine months old and still have their “egg tooth”. They are healthy and active. They live outside with water dripping constantly into their water dish. (It is very hot here in the summer)

The fifth baby is in the junior author’s care and has thrived in a 60 cm x 60 cm low-sided glass terrarium (breeder flat) provided with potting soil and sphagnum moss as a substrate, containing 2 small water dishes, 3 hide boxes and 2 living plants. A Gro-Lux light provides illumination and the youngster often basks beneath it for an hour or more. However, except on the coolest days, when overnight temps may drop to around 60 degrees where the terrarium is located, he will emerge from his shelter ready to eat as soon as he detects nearby human presence. I have never seen him basking later than midday and so the light is usually turned off after only a few hours. Supervised outdoor sunning is also carried out for short periods. The diet of this youngster is perhaps less varied than that of his siblings, but also includes small garden snails and earthworms of which he seems extremely fond. A consistent, frequent, but unexpected behavioral trait has been to butt the hand that feeds him. He will withdraw his head and “charge” as if to discourage meddling in his food supply. A young female M.e.p. in the Junior author’s care since 1983 has never been observed butting. The little tortoise is capable of producing a surprisingly loud hiss. Between January and August, 1998 this tortoise increased its weight from 102 to 141g and has grown from 79mm to 94mm carapace length.

June, 2001 note: Every season since my “amateur” success story, all of the eggs laid have been dribbled out one at a time, and I have not been able to duplicate my breeding success.


The Senior author wishes to express her thanks to William Espenshade, III and to Vic Morgan for their help and expertise.
 
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