Posted by:
FR
at Thu Feb 9 18:39:14 2012 [ Report Abuse ] [ Email Message ] [ Show All Posts by FR ]
This is an important question. And its one that has or should change over time. You know, as we learn and progress.
Many keepers critize methods of keeping based on a precieved longevity goal. When the methods of keeping are successful, I have to now question the importance of longevity or more importantly how it related to natural varanids and to captive varanids.
In captivity, longevity was a measure of success base of the fact, we in captivity could not keep them alive. So we measured days, then months, then years, then decades.
In 1970 I worked at Ross Allens Reptile inst. There was a researcher who visited and was doing a survey on longevity in snakes. He surveyed all the U.S. zoos.
He said, the average longevity for snakes( what I was interested in that at time) was two years. He followed that statement with, it took that long for snakes to perish when kept in poor conditions.
At that time I was several generations into breeding certain species of colubrids.
Years later, I worked at the Arizona-Sonora Desert Museum, ASDM.
I worked in both exhibits and the reptile department. At that time 1972 to 77, I was now more generations into many colubrids, much like I did with varanids.
One higher up was very interested in eggs, that was his major, so we talked extensively. He wondered why the folks in the reptile department were not ding snakes. So he hired me to do so and to critique on the department.
So I did, I researched the departments records and discovered the average lifespan was that aprox 2 years. What was odd was, there were many many individuals that were euthanized.
So I researched longevity records.
So in the past longevity was a yardstick of captive success. That was not considering events like reproduction. Which was rare at the time.
If you researched the records, all or nearly all long lived individuals were males. And in most cases, undermetabolized to a point they never reached normal adult size. I could not find a record for females, muchless breeding females.
Back to the present. So what do longevity records represent? How long an animal lives or how much life an animal has experienced.
So when I started working with monitors, I include, "basic life events" which include growth and reproduction, plus longevity.
It seems those concerned with fruitless longevity don't or rarely produce animal.
There are those like Crocdoc that keep a pair(?) and see how long they can control the same events over and over, many zoos did that as well, and there is nothing wrong with that, but theres nothing really right about it either.
For instance, its of great interest to me to explore there potential, for instance how many clutches can they produce in a lifetime, and it doesn't matter how long that may be, or not.
It becomes about selective reasoning, you pick success is how long an animal lives, and I think about how much an animal participates in its ecosystem. How much it contributes and for how long.
As I mentioned, there is little to no information on this from nature.
My bet is, the majority of wild female lacies, or any species for that matter, do not reproduce for more then five years in nature. And we exceeded that without problem. Even with our horrible desert conditions.
So any real thoughts on this folks? Thanks
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