Eyes on or hands on? A discussion of human interference

[peter]

(09-30-2014, 09:14 AM)'GuateGojira' Wrote: Good question Richardlri, besides it seems that those sensationalist news always avoid the fact that LESS than 5 tigers have died by radiocollaring in India, Nepal and Bangladesh, together.

Like you say, radiocollars do a very good job on lions, jaguars, leopards, cougars, lynx, elephants, donkeys, etc. etc. etc. [img]images/smilies/biggrin.gif[/img]

 

SEDATION IN CAPTIVE BIG CATS

Although the number of accidents is limited, it is a fact that sedation results in problems every now and then. There are many reasons.

In captivity, humans darting big cats disregard protocols at times. It isn't always the vet who darts, that is. I also noticed they seem to disregard the mood of an animal. Animals sometimes are aware of what is about to happen and they act accordingly, meaning the dose administered isn't always correct. Not in those circumstances. Three examples.

- One male captive lion of 400-420 pounds in excellent shape got the correct dose, but wouldn't go down. He got another dose. Same effect. After the third he collapsed, but it took a long time before we were able to transfer him to the stretcher. When we carried him to the operation theatre, he started to growl. Than he moved his muscles and head. On the operation table, we were unable to restrain him any longer. He got another dose and the vet started his work, only to discover the lion just didn't want to cooperate. Another dose was administered. Than we had to carry him back to his cage in a hurry. We moved him from the stretcher to the floor with six as fast as we could. When the door was closed and locked, he went for us with everything he had. Just in time. All this after a dose that would have killed a decent rhino. Exception?

- Two adult male Amur tigers had to be treated. I was to measure them, but assisted when they had to be moved to and from the theatre. One male was 211-215 kg. (weighed at Schiphol Airport a few years later). He got the correct dose, but I saw him smiling all the way. I measured him, but we decided against weighing because of the risks. His brother, only slightly smaller, went down fast, but was nearly fully awake during the treatment. When the vet was done, we carried him to his cage and unleashed him. Then I measured him. But I had to step over him when he suddenly woke. Another narrow escape.

I never saw a more angry animal later. I really thought he would destroy the cage and all the rest of it. That's when I accepted that a male tiger, in an open fight, probably stands a very decent chance against a bear of similar size and weight or even a larger animal. Not disgarding the great brown bear, but the big cats have something many overlook. Not character, temper or aggression (bears do not lack in these departments), but something different.  

- The big brown bear I was supposed to measure and weigh never went down. When I entered the building with my tape, I was overrun by those running for their life. The bear wasn't cooperating.

Some animals are fully awake when they are sedated and treated. Some respond and others don't. Some forget about it, but others do not. Some respond differently when they are sedated again later, but others do not. You just never know.


LESSONS

IN sedation and captive big cats, things can go wrong. There are different reasons. My guess is personality and individual variation are the most important. Than there is bad days, mistakes and coincidence. Even when everything goes well, a wild tiger sedated before, like the Sauraha male, might find something extra to run and hide. Stress?


SEDATION AND COLLARS IN WILD TIGERS

Is everything described above a good reason to refrain from sedation in wild tigers? No for two reasons. In the great majority of cases, things work out just fine. Two is sedation allows for measurements, blood samples, weights and (through collars) invaluable information on territory, social habits, hunting, food and a lot more. 

Is it worth it in wild tigers numbering about 3000 in total considering the potential risks? I again think yes.

A large part of what was known about wild tigers before radio-collars proved to be partly correct in some cases and plain incorrect in many others. With the information collected through collars, biologists and those responsible for management, reserves and everything connected were able to make adjustments. Maybe just enough to stop the collapse of tigers nearly everywhere.


MEASUREMENTS

PC said the new info didn't add a lot in general terms. True? I disagree. Some reasons:

- We now know tigers adjust to circumstances: bad conditions and stress seem to result in dwarfism, whereas good conditions and no stress result in the opposite. How does it work? We don't know. Why is it adult male Terengganu tigers, in less than half a century only, lose 6-8 inches in total length and even more weight if we know the natural conditions didn't change a lot? Why is it male tigers in more central parts of south-east Asia, exposed to similar factors as those in Terengganu, do not? Collaring might provide answers.

- We now know tigers in overpopulated smallish reserves with otherwise good conditions in India seem to get larger (heavier) than tigers in other, but otherwise similar, regions. A result of competition? If so, how does it work? Why foremost in Indian reserves? Collaring again might provide answers.

- We now know information collected by hunters a century ago (regarding size and weight) was close to what we see today in general terms, meaning many were accurate and trustworthy. This means we can use the information they collected. Information on the size of today's tigers can be compared when the method used was the same. Collaring over a long period of time might provide answers to questions regarding developments we didn't really know about. Do smaller tigers disappear in some regions or is there another factor we don't know about? Collars might again provide answers.

- We now know a bit about gene loss and the effect on size. We also know a a bit about the way in which tigers, in some regions, regenerate when conditions change again. Information about the size of wild Amur tigers has proved to be of great importance in many ways. The reason is collars.


THE MEANING OF MORPHOLOGICAL DATA

I've been collecting data for a long time. The averages I found are different from those who reported on averages a century ago. The main reasons seem to be sample size and no selection for size. What is the value of these data?

Well, I now know a bit about the morphological differences between wild and captive tigers of the same subspecies. Could be of use when tigers are re-introduced in new regions. Perhaps they could be selected or trained. Trained? Yes. Different facilities now use trainers and it seems to have an effect. 


RADIO-COLLARS AND WILD TIGERS

One day, when wild tigers exceed 10.000 again, we might decide against sedation and collars. Because we know enough. But not now.

As we continue, biologists will learn about sedation and collars. Just as they learned about the disadvantages of the Aldrich-snare. Maybe tigers react different to collars than other cats. My experience in captive animals suggests tigers are more sentitive to circumstances. Maybe biologists need a different device in tigers.

I definitely agree with PC on wild animals and humans. To see a wild big cat with a collar is sad and even degrading. But the advantages, like Guate said, outweigh the disadvantages and in species walking the edge, like the tiger, it could prove to be the difference. Let's hope we are not wrong. Reply