Some translated notes on G. sulcata

Testudoresearch

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A SUMMARY OF CLIMATIC AND BEHAVIOURAL DATA ON GEOCHELONE SULCATA

Published in French in ‘La Tortue’ 1988 – 2006

Translation by Jenny Robbins for the Tortoise Trust. www.tortoisetrust.org

This data is an unedited summary of raw data contained a series of comprehensive articles published in French in the journal ‘La Tortue’ over many years. This is uniquely reliable data in that it was written and compiled by people who have worked in the field with this species for more than two decades. The full articles are very well illustrated and contain a wealth not only of basic data, but extremely valuable commentary and first-hand observations of this species in the wild. It also paints a catastrophic picture of rapid population decline in recent years to collection and habitat destruction. There are some really interesting observations on behaviour here. Enjoy.


(1) LA TORTUE No 9 OCT 88
- SEE MAP
- Arid habitat (45 Celsius in shade in April) far from fresh water sources, difficult to access, does not rain every year.
- Lives in Rameroue area in the FERLO



(2) LA TORTUE No 10 FEB 89 JEAN-PIERRE POUVRAEU
- Males can weigh 100kgs, females 60 max
- Mating can occur several times a day & several days running with the same female
- Can lay several times in several days in different places, probably to foil predators
- The female lays her eggs using her back legs that she bends to soften the landing of the eggs Using them like a funnel. She then covers them with 4-5 cms of earth. Then she wets the nest with water that she has on either side of the cloaca. It appears that this is important for the eggs themselves. She then lays 2 or 3 more on the surface of the nest and then blocks up the nest completely and waters again. May be a ploy so that predators take the few and don’t look any further.
- At birth measure 20mm long x 47mm wide in general.
- Growth is very rapid. Great difference in size of juvenile and full adult size

(3) LA TORTUE No 10 JUNE 1989 J.P. POUVREAU
- SANDY REGION, NEARLY DESERTED, SCATTERING OF TREES AND DRY GRASSES.
- Between Dec & March violent winds & sand storms, especially in Feb & March windiest months in Senegal. Also coldest period with very low temps at night.
- In April can be 40 Celsius in shade at midday in the Ferlo.
- Sulcata active for a great part of year.
- When period of wind stays hiding in hole
- From Dec-April can be seen in daytime
- From May-Sep, very hot period, goes into semi-estivation. In day stays in hole protected from sun. Hole can be 5m deep. Comes out very early or even at night to feed.
- Instinctively digs very deep burrow. It is primarily a place of protection & estivation.
-This burrow, necessary for its survival, has unfortunately an inconvenience it makes the tort easy to find both by animal predators & humans.
- Adult can weigh between 40-100kg and due to this bulk the animal shifts heaps of sand, leaving tracks like jcb caterpillar marks. This makes his burrow easily identifiable especially as it is often located at the foot of a tree.
- This excavation also attracts carnivores and poisonous snakes (naja and desert viper)
- Jan 1989 temp variation from 12 Celsius at 7 am to 35 Celsius at 3.00 pm.

(4) LA TORTUE No13 JAN 1990
-Males have similar behaviour as Gopherus when mating. Both species Fouisseuses and habitat & way of life similar & morphologie.
-The males “Fight for the Lady” One male on seeing another coupling with a female will rush forward regardless of spectators and separate the “lovers”. He will provoke the other male and a fierce fight will ensue. The highly developed forked gular makes for resounding jousting. With locked gular they violently try to turn each other over. This combat most often ends with one of the males either being overturned or running away.
- Very often in the wild this will lead to the death of one of the combatants. This would appear to be a “waste” for the species, a sort of behavioural error. The gular is often so long and developed that it actually impedes the animal. The tortoise can only carry its head on one side of this fork or the other. This would seem to be a negative adaptation hindering the animal. Strange evolution?

(5) LA TORTUE No23
- Sulcata live in band 500 kms wide crossing central Africa from W to E.
Mauritania, Senegal, Mali, Nigeria, Tchad, Sudan & Ethiopia (Latitude 20 Degrees north)
- In Sengal lives between Gambie and Senegal rivers
- In Ethiopia seems to be partially eradicated
- In Sudan possible that relatively large populations survive
- Tchad, Nigeria & Mali has become rare, no longer seen along Niger
- Mauritania very few - climate more Sahara than Sehal
- Only place where found in original biotope is in triangle between RICARD TOLL, DJOURBELL and HAYE on Mali border
- About 30 specimens were released at RESERVE DES SIX – FORAGES also at RESERVE DU DOLI
- At slightest alert they rush to their shelter &burrow as fast as they can to bury themselves
- Live in vast territories with a low density per km2
- Calculated maximum of 10,000 specimens in whole territory
- Species which digs the deepest burrows, some more than 4 metres long burrow with fore paws with short, very rapid jerky movements
- Live like hermits in subterranean “palaces” which they will sometimes share with jackals, jerboas & vipers
- Hydric qualities similar to Camel; urine in powder, capacity to drink in one go more than 15% of its body weight
- Mating impressive! Bangs, bellows, forepaws deeply “rooted” on female. Surprising violence for such an animal
- Dates and length of laying season….. Senegal seasons fairly regular, alternate btw dry & wet “winter” corresponding to our summer….wet between July & Oct. Due to this thermal regularity the laying can be widely spread out through the year and depending on the frequency of the rains, incubation can vary from weeks to several months
- Breeding in Feb/March, laying in april, sometimes also from nov to feb
- Lay about 20 eggs although large females can up to 30 this is max poss
- Eggs 40mm , 35g approx.
- Incubation: 100 days for hatchings just after first rains, but can take 5 to 6 months if thermic disturbances due to early rains
- Opportunistically omnivorous - succulents, fruits, grasses also left overs & waste, lizards, crickets, gerboas and also carrion & rooting foodstuffs

( 6)LA TORTUE No 35 AUG 1996
- Sanitary Centre at Sangalkam plus nursery for juveniles 110 animals plus 95 babies at end of july, more expected , plus Village des Tortues at Noflaye is developing.
- Typically14-21 eggs per female -40-65g (6x more than Hermann egg)
- Incubation 97-190 days - average 110
- Laying season Dec to April, 2 per female
- Hatching Jun, Jul & Aug. Juveniles arrive just before the rains which aids survival due to hydration opportunities and plentiful shoots and grasses “in natura”.
- Contrary to European tortoises who lay in a hard and often clay substrate, these are laid in soft sand allowing easy exit and no need to soften ground
- The laying females were those reintroduced in 1995 from Holland, Mauritania and Paris. Animals had therefore completely adapted to new environment.
- Adults liked peanut leaves dry and not very nutritious

(7)LA TORTUE No36 NOV1996
- Sexual maturity 10-12 for males ,bit more for females
- Continues to grow rapidly until 20 years.

(8) LA TORTUE No44 NOV1998- B DEVAUX
- Appears that no longer any surviving in natural environment. Practically no juveniles found in the wild. Conservation programme to be started & monitored by gamekeepers & villagers in RANEROU village
- See map p19

(9) LA TORTUE No 48 NOV 1999- B DEVAUX interviews THOMAS DIAGNE
-Sahel means “shore” in Arabic and well describes this land between the dunes of Mauritania and the wetter southern part of the country
Sahel has varied biotopes ranging from the extreme desert aridity to the 1st savanahs of Niokolo-Koba.
- One of main roles of Sulcatas is the dispersal of seeds of local flora . Faidherbia albida, Acacia raddiana, Boscia senegalensis, Zizyphus Mauritania. They are great fertilisers – compost and the passage though their digestive system facilitates the germination of certain seeds.

(10) LA TORTUE No 49 FEB 2000 B DEVAUX
- Researching if genetic diff between Sudan sulcata and Senegal. Only visible diff is slight . Shell slightly less orange than in Senegal, Mali, Mauritania, and in Sudan greyer and more earthy: not enough evidence yet.

(11) LA TORTUE No75 NOV 2006
-Spectacularly powerful animals
- Takes dried grasses and straw into burrow as food store in dry season cf. 1904 Captain Vallier
- Known as the tortoise that cries - eyes often irritated by sand
- Most expressive and dynamic of big torts; galaps, aldbra. sulcats
- Excessively fearful, most curiosity of them, contrary to others who will hide for hours in their shells, sulcatas cannot resist putting an eye and then head out minutes after having puffed with rage at being handled, defying intruder that disturbed them.
- Probably the tortoise the closest to humans, cooperative behaviour, e.g., large male came to slap B. Deveau’s leg with gular both friendly and aggressive to show he wanted human attention, others come and will place paws in lap out of friendliness.
- Hate being manipulated
- A Cadi (researcher) says; these tortoises follow a cycle. One tortoise can live in several burrows, that several can live in the same burrow and that a tortoise can occupy a hole that it did not dig. Also they have a very precise knowledge of the countryside and the places where a certain number of burrows can be found. In the event of a landslide or the destruction of a hole by the rains, they are capable of walking 5 km to find an old burrow. With telemetric equipment it has been shown that the animal will find a precise burrow straight away, directly.
- Tortoises captive bred in Senegal at Noflaye appear to adapt to the wild but test will be if they still know how to burrow in dry season 2007. A. Cadi has reservations about the possibility of European captive bred sulcatas adapting to their original natural environment and if they can’t he questions their reproduction in captivity.
- There was release in July 06 in the reserve of Katane. The torts were fitted with radio-transmitters, students track them daily. This experiment will continue for one year to observe the ability of this species to adapt when returned to its original environment. End Nov 06 only one tort had not been found. The others have stabilized, dug holes and put on weight, indicating good adaptability. Researchers will continue to track each tort until end of 2007.
 

Yvonne G

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Most of what I've read of Tom's threads are proved correct in this interpretation. I especially enjoyed reading #6 where it says the babies hatch out right before the rains, ..."aids survival due to hydration opportunities and plentiful shoots and grasses “in natura”.
 

edwardbo

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Only got to read a few paragraphs,like I said nature is a beautiful song ,listen.........( you know they are going to lay their heads on the chopping block...).....much love....(and laughs))......much more to say but....time is not on my side...
 

Levi the Leopard

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Re: RE: Some translated notes on G. sulcata

Yvonne G said:
Most of what I've read of Tom's threads are proved correct in this interpretation. I especially enjoyed reading #6 where it says the babies hatch out right before the rains, ..."aids survival due to hydration opportunities and plentiful shoots and grasses “in natura”.

Yes! I liked this too.
 

Testudoresearch

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edwardbo said:
Only got to read a few paragraphs,like I said nature is a beautiful song ,listen.........( you know they are going to lay their heads on the chopping block...).....much love....(and laughs))......much more to say but....time is not on my side...

OK... more....

Here's a PDF with some distribution maps and (very rare) habitat photos.
 

nearpass

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Team Gomberg said:
Yvonne G said:
Most of what I've read of Tom's threads are proved correct in this interpretation. I especially enjoyed reading #6 where it says the babies hatch out right before the rains, ..."aids survival due to hydration opportunities and plentiful shoots and grasses “in natura”.

Yes! I liked this too.

How long do you suppose this 'humidity' lasts? Then what? No 'closed chambers' for a year or two in these arid areas, and even burrows probably only offer 30 something% humidity at best after a short while. Diet must also become pretty meager very quickly. I'd guess there would be much 'down time' and estivation fairly soon, and probably quite a limited survival rate.
 

Tom

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nearpass said:
How long do you suppose this 'humidity' lasts? Then what? No 'closed chambers' for a year or two in these arid areas, and even burrows probably only offer 30 something% humidity at best after a short while.

What do you base this on? I live in a very arid dry climate. We get very little rain and we don't have a humid or wet season at all. My three foot deep burrows hold a lot of humidity all summer long. They stay at 55-65% all by themselves and its easy to get them higher if I add some water. My adults dug a 22' long burrow and that one stays 65-75% at 10-15' from the surface. I wouldn't imagine that it would be more humid here than it would be in the Sahel. My climate is MUCH drier than theirs.


nearpass said:
Diet must also become pretty meager very quickly. I'd guess there would be much 'down time' and estivation fairly soon, and probably quite a limited survival rate.

My friend Tomas tells me that they drag vegetation down into their burrows at the end of the rainy season. He said they line the whole burrow with it, and then eat it all through the dry season. This info is also listed in the text that Andy posted above.


So even just a few feet below ground, temperatures are quite comfortable and humidity relatively high. There is also no shortage of food.

There will be info on this in Tomas' new sulcata book whenever it finally comes out. Soon we won't have to speculate.
 

edwardbo

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If it's about the temps why do they dig so far down,maybe they are not seeking humidity/ moisture BUT they are JUST trying to get out of the sun.


If they wanted water wouldn't they pitch the burrow to funnel water in and have a pool to play in.?


I know it will have moisture under ground in the tunnels.
 

mike taylor

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I think these guys eat more protein than I've read or seen here in the forum . I read here in this thead they eat lizards and bugs . So Tom do you feed animal protein to your sulcatas ? Or do you give plant proteins? I just find it hard to believe an animal of this size don't take in protein in a higher levels than some dietd suggests.
 

Testudoresearch

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nearpass said:
How long do you suppose this 'humidity' lasts? Then what? No 'closed chambers' for a year or two in these arid areas, and even burrows probably only offer 30 something% humidity at best after a short while. Diet must also become pretty meager very quickly. I'd guess there would be much 'down time' and estivation fairly soon, and probably quite a limited survival rate.

Absolutely correct. I am afraid too many people simply have no comprehension whatsoever of the realities of geography and climate and draw totally the wrong conclusions.

To give an example, I live quite close to the edge of Europe's only true desert (if you have ever watched Clint Eastwood in those "Fist Full of Dollars" movies you have seen it, they were filmed here). Our tortoises too hatch as the first rains of the "wet season" begin around mid-September. That term is relative. There is a rise in ground moisture levels... and a rise in general ambient RH, but only for a short period. Once the clouds pass, the sun is still strong, and warm, and very quickly dries things out again. The rain is enough to nurture the highly specialized desert plants (you see the same thing in Arizona), but if anyone believed that this meant that from the time of hatching onwards things for those tortoises were "wet" or "humid" they would be seriously mistaken.

Absolutely not.

This is all established geography and the terms "semi-arid", "xeric" and other terms used in those French publications have a very specific, technical meanings to geographers and biologists. It is worth getting familiar with them. If you read that material and skip over them, not entirely understanding them, you will reach erroneous conclusions.

Such erroneous conclusions are regrettably very common among pet keepers.

Burrows are a response to inhospitable conditions "above ground". They do indeed provide more humidity than on the surface - Gopherus and Testudo horsfieldii use the same strategy. As we have seen from Kirsten Berry's results, however, the levels in those burrows are still quite different from what many have claimed.


mike taylor said:
I think these guys eat more protein than I've read or seen here in the forum . I read here in this thead they eat lizards and bugs . So Tom do you feed animal protein to your sulcatas ? Or do you give plant proteins? I just find it hard to believe an animal of this size don't take in protein in a higher levels than some dietd suggests.

Always worth remembering that the world's largest animals are herbivores... Elephant, giraffe, Galapagos tortoises for example.

Evolutionary size is not related to protein intake in that way.

From my observations, arid-habitat tortoises will eat any available food source - but the key word here is "available". It is very rarely available. They are not hunters... and there are far more efficient animals out there that usually grab any "spare" delicacy long before a tortoise can get to it. So, intake tends to be very low indeed. They may well consume a bug on a leaf (if it does not get out of the way fast enough), but it is incidental intake. I have looked at fecal pellets from various wild tortoises over many years, and I have found odd examples where they have consumed such items, but it is certainly not routine. If a dead lizard is found, though... they would tend to eat it.

I would absolutely not go down the route of feeding animal protein to herbivores. It is a disaster area, and caused huge damage when the practice was widespread in the 60's and 70's.
 

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Re: RE: Some translated notes on G. sulcata

mike taylor said:
I think these guys eat more protein than I've read or seen here in the forum . I read here in this thead they eat lizards and bugs . So Tom do you feed animal protein to your sulcatas ? Or do you give plant proteins? I just find it hard to believe an animal of this size don't take in protein in a higher levels than some dietd suggests.

Read my diet threads then.
 

shaf1457

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One of the interesting statements I read is "Opportunistically omnivorous - succulents, fruits, grasses also left overs & waste, lizards, crickets, gerboas and also carrion & rooting foodstuffs". They are using the term omnivorous to describe the sulcatas they were observing. These guys were observed eating lizards, crickets, gerboas, and carrion. To me this does lean to more of an omnivore status than a straight herbivore status. Granted the term opportunistic is also used here meaning they are going to eat what is just in front of them than chasing/hunting these things down. But the point is they still do eat it, I would imagine that an animal that is a true herbivore would not eat these items even if it was laying right in front of them. So I would think that having protein serves some type of an importance in their diet otherwise why would they eat it.
 

Tom

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mike taylor said:
I think these guys eat more protein than I've read or seen here in the forum . I read here in this thead they eat lizards and bugs . So Tom do you feed animal protein to your sulcatas ? Or do you give plant proteins? I just find it hard to believe an animal of this size don't take in protein in a higher levels than some dietd suggests.


I don't intentionally feed any animal protein, but I'm not going to criticize anyone who does offer an occasional small amount. I don't think it is necessary or to be encouraged, but I don't think its harmful either. In years past, when everyone thought that protein caused pyramiding, I was maniacal about avoiding as much protein as I could. I would look up the protein content of everything and stick to the things I thought were lowest. It was often confusing and the info was often contradictory due to the multiple methods that can be used to measure protein levels in plants. Once I saw the 2003 Austrian study, and had a couple of interesting conversations with Richard Fife about this subject, I relaxed tremendously on the protein thing. I grow my own alfalfa and occasionally mix some in with my bucketfuls of grass, weeds and leaves. Likewise, some other legumes occasionally find their way into the grass mix, but not much and not often. Mine have on rare occasion had kidney, lima, garbanzo, white, and pinto beans, peas, green beans, etc. That may sound like a lot when listed this way, but understand ALL of these things make up a tiny fraction of one percent of what they eat in a year.

My friend Tomas from Senegal tells me that wild sulcatas regularly eat the dead animals that go into their burrows to escape the scorching African sun while they die. We have one keeper here on the forum who lives in FL that feeds whole fish to his sulcatas. My friend Dave Friend in Ojai has one sulcata the he has personally witnessed hunting, catching and eating live gophers. I saw a nature program on the Galapagos once where a big tortoise was standing up tall right at the waters edge. He would stand really still and all the little finches would come down to get a drink and take advantage of the shade he offered. He would suddenly drop down and smash as many as he could and then back up and eat the smashed birdies. Then he'd get right back in his spot, stand tall and still and wait... Last bit of anecdotal evidence: Apparently Bert Langerwurf used to toss leftover chicken and turkey parts, bones and all, into his sulcata pen. He seemed to think they really liked it and found amusement in people's notion that any protein was horribly bad for them.

There are so many unanswered questions about what is best for our tortoises...
 

Lilyloveslettuse

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Isn't that the truth!!!! And each tortoise is different from the next - just like people. :) We can only go by common sense, general information and what our own individual tortoise seems to go for. A comfortable, healthy, happy life. :)
 

mike taylor

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Re: RE: Some translated notes on G. sulcata

Will said:
mike taylor said:
I think these guys eat more protein than I've read or seen here in the forum . I read here in this thead they eat lizards and bugs . So Tom do you feed animal protein to your sulcatas ? Or do you give plant proteins? I just find it hard to believe an animal of this size don't take in protein in a higher levels than some dietd suggests.

Read my diet threads then.

Can you post a link ? Please sir.
 

mike taylor

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Re: RE: Some translated notes on G. sulcata

mike taylor said:
Will said:
mike taylor said:
I think these guys eat more protein than I've read or seen here in the forum . I read here in this thead they eat lizards and bugs . So Tom do you feed animal protein to your sulcatas ? Or do you give plant proteins? I just find it hard to believe an animal of this size don't take in protein in a higher levels than some dietd suggests.

Read my diet threads then.

Can you post a link ? Please sir.

Woukd really like to read your dietary threads sir .:D
 

Testudoresearch

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I have been making a few inquiries through various contacts, and in a few weeks, should have some quite relevant, factual information to add to the above. It is important to make one thing clear. When discussing the conditions a species experiences in nature, you do need to take full account of variables throughout the range. Sulcata has a huge geographical range. Some elements of this range are more typical than others of 'optimal' habitats, with some representing extremes - either higher, or lower than typical (whether we are speaking of temperature, or humidity, or any other factor). If you only concentrate on one area, you could well end up being seriously misled. How do you know you are not taking one of the 'extremes', and interpreting it as an average? This is like taking one piece of a jigsaw and convincing yourself that you know the details of the entire picture. In the absence of reliable information, it is best to keep an open mind, and await further evidence.
 

Jess53

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Thank you for what must have been a lot of work! I learned that some things I had inferred were correct, and learned a lot from the information!
 
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