Hybrid tortoises

[Alan1]

Originally Posted by EJ

...and that is my point when you take animals out of the wild that have been imprinted. They have trouble acclimating to the conditions and diet we offer them.

When you are talking about second generation animals... it is a totally different story. As long as all the basic needs are met almost all tortoises can be kept under identical conditions.

Yes, it's the same with tropical fish, wild caught Angel Fish for example require a Ph of about 5 to 5.5 and live food, anything else and they will die but captive bred can tolerate anything between 5 and 7 and flaked food

[Geomyda]

Originally Posted by romski

“I don't have a great deal of first hand experience but it appears to be even easier with aquatic chelonia.
You only have to look in your own back yard at how well they establish themselves in the UK given the opportunity.”

Ed I am afraid you are guilty of trying to align popular notions on feral UK turts with your behavioural imprinting idea. You couldn’t be further from the truth.

In Langtons paper of 2011 he postulates that some 4000 animals may be wild in UK ponds and that London had a population of about a 1000. This is probably in the right order of magnitude. About 25,000 green turtles are imported annually into the UK with a considerable attrition rate. For the London area, of those that survive and are then no longer wanted as pets some 250 are estimated to be released each year. Recently, the Olympic clean-up work of London ponds did produce good statistics which were a base for Langtons paper. I have some of those animals and have exchanged and visited with naturalists working the projects in the borough.

The numbers hardly support a view that they have established themselves well in the UK, they are not even thriving but are just surviving with expectancy we think of less than a year for most of them after release. This year I have already taken receipt of one which survived only a few days.

Over the years, I have like others, taken on many animals to be rehomed, mostly Sliders, Cooters and Maps (green turts). These families are genetically very close and hybrids and integrades are commonly seen (bred, I suspect, for commercial reasons to overcome import restrictions).

As mentioned... all tortoises have the exact same basic needs. The need for different methods for keeping different species arises from trying to acclimate WC animals for the most part. Animals become behaviourally imprinted over time. Animals also obtain their nutrition through adaptation. If you don't have an animal that is imprinted and provide all its basic nutritional needs in a simple form you can keep almost all tortoises under identical environmental conditions and feed them identical foods... with very few exceptions.

Given your imprinting hypothesis above, one would think that the survival rate of the green turts would be the same across this closely related group - it is far from that. Even within the pseudemys genus there is a marked difference in survival capability say between the River Cooter and the Red Bellied Cooter. Some of the hybrid/integrades survive better than the pure species however it is impossible to determine which lineage contributes to the success.

In the lovely Atlanta climate with which you are blessed, your hypothesis may work, but put natural endemic stress on the animals and the hypothesis fails for those not in a home environment.

Andy and Yourself both add colour to the hobby with insight from your own perspectives - which is valued, please dont make it make it dogma.

Interesting post, the huge numbers of what appear to be hybrid Green terrapins that are currently in the trade suggests that hybridisation is a common in the breeding farms of the USA and China.
Some years ago, I attended a lecture about the diversity of Meditterranean tortoise species. From memory, the presentation indicated that cross breeding was unusual in the wild populations that overlap. I seem to remember that the anatomical differences in the genitalia of the different species made successful copulation unlikely.
That said, in some of the Freshwater and semi aquatic turtle species such natural geographical overlaps frequently seem to result in natural "inter grades".

[romski]

Ed you stated As mentioned... all tortoises have the exact same basic needs. The need for different methods for keeping different species arises from trying to acclimate WC animals for the most part. Animals become behaviourally imprinted over time.

The capability of survival by some animal species in their own environment is not behaviourally linked it is physiological. This was shown by D.Jackson in many of his papers and later his book when he compared the O2 uptake capabilities of different turtle species many within the same family.

The dogma comment comes from the continual almost religious push that behavioural imprinting is the (only) answer.

The Angel fish comment brings us back to the more interesting thread. In the seventies when discus breeding started the same problems were encountered and PH, food and tannins were all factors that were considered. I eventually bred them from a second generation stock.

The mechanism that enables the later generation successes is unlikely to be imprinting but merely rigorous genetic selection early in the breeding process. Those of the feral turtles that survive may not have been successful due to successful imprinting but rather to a more amenable genetic make-up compliant with the harsh UK environment.

Remember that the number of animals that survive the outdoors in the UK are a minute proportion of the number released and they may have genetic attributes that make that fraction of a difference. Taking this further, if those same animals were bred, then just like the Angels and Discus the likely proportion of the progeny surviving outside would be significantly better than seen by their parents.

The question developing now has to be; when you made the assertion above was it based on your experience with animals that are several generations into burn and had the genetic filter already happened?

I am in not disputing the imprinting concept as I have seen this myself with my animals and especially with fish, I just don’t think it as big a factor as you do.

This is a good debate and leads me ask; If a breeder were to take Red Foots into Kazakhstan and imprint them there, would they survive outside as do the Russians?

Rom

[EJ]

How is that dogmatic?

Last time I looked Testudo, Sulcata, Leopards, Aldabras... do not naturally occur in the UK yet there are people breeding these species in conditions that is nowhere near what they would experience in their natural environment. If you don't consider this proof it is at least evidence of their adaptability. I don't see how you can dispute the point.

Nowhere did I say you or anyone else had to believe or follow my thoughts...

Originally Posted by Geomyda

"The term derives from Greek δόγμα "that which seems to one, opinion or belief"[3] and that from δοκέω (dokeo), "to think, to suppose, to imagine".

Ed, some might suggest that the following statement made by you earlier is rather dogmatic:

"It's been pretty much proven that this is true with most species in captivity when you consider that many species thrive and breed in captive environments that are no where near to those they would encounter in the wild"?

[Geomyda]

In terms of adaptive behaviour Ed, there is work by the Austrian Zoologist Konrad Lorenz, which describes imprinting behaviour in Birds. Most famously, the clutch of Greylag Geese that imprinted on him decades ago. This involved him having to swim around Austrian Lakes trying to re establish natural Goose behaviour.
I have visions of You wandering around Atlanta with herds of fifteen species of Tortoise trying to teach them life skills!!

[EJ]

hmmm... interesting. Why would I try to imprint a tortoise to make it more difficult for me to keep them? I have no intention on releasing them into the wild.

Originally Posted by Geomyda

In terms of adaptive behaviour Ed, there is work by the Austrian Zoologist Konrad Lorenz, which describes imprinting behaviour in Birds. Most famously, the clutch of Greylag Geese that imprinted on him decades ago. This involved him having to swim around Austrian Lakes trying to re establish natural Goose behaviour.
I have visions of You wandering around Atlanta with herds of fifteen species of Tortoise trying to teach them life skills!!

[Balboa]

Great Thread,
I've suspected for a long time that the majority of tortoises actually have nearly identical "optimal" environmental and nutritional requirements, and what we tend to think of as their "typical" conditions are really just the extremes that they learn to tolerate through behavioral adaptation.

In other words, tortoises grow during the warm and humid times of the year when plants are actively growing, and simply "maintain" during cooler or drier seasons.

This is of course simply arm chair theory

[EJ]

Nothing wrong with this.

Originally Posted by Balboa

Great Thread,
I've suspected for a long time that the majority of tortoises actually have nearly identical "optimal" environmental and nutritional requirements, and what we tend to think of as their "typical" conditions are really just the extremes that they learn to tolerate through behavioral adaptation.

In other words, tortoises grow during the warm and humid times of the year when plants are actively growing, and simply "maintain" during cooler or drier seasons.

This is of course simply arm chair theory