Hi Bob
I just used dogs, because everybody knows them so it's easy to explain, but you are completely correct that most of the problems dogs have, are because they were bred to have noses that are insufficient for effective breathing etc. What I should have said (was my bad I should have been clearer) is that in the same way that dogs were selected for specific traits, so antelope are now being selected for their colour (or for that matter selection based solely on horn length could be questioned too). The thing is that each chromosome in an animal carries multiple genes, so the chromosome carrying the gene for gold colour could also be carrying genes that affect the immune system or bone density or speed or...or...or..., we just don't know yet, but it could also carry positive effects.
I wouldn't compare them to labradors, since they have the advantage of being human companions and get to go to the vet and get great food etc. so less obvious negative impacts could easily be overlooked, and the same would apply to comparing it with cattle to a degree, but I have spoken to some vets and they have specifically told me that lighter coloured animals, irrelevant of shape or size, are more susceptible to developing skin cancer, because they have less melanin; this is an example of an unintended negative effect of selecting for a specific trait.
I would rather say let's look at the wolves that have been mentioned quite a few times in this thread, the wolf colour variants seem to occur relatively commonly nature, from what I understand from other comments and from what I have been able to see (unfortunately only on documentaries), we could also add boomslang (translated as tree snake, it has no English name) their colour ranges from brown to olive to bright green also under natural conditions and there are many other examples of animals that occur in different colour phases under natural conditions.
Taking the above into account then from a purely nature conservationist viewpoint we could the ask the following question: If colour variation holds no additional negative effects for the antelope why was the copper or coffee coloured springbok (which still blends nicely into the veld and with herds of normal animals and still has lots of melanin) or golden wildebeest or any other colour variant not the dominant/most common or at least just more common (such as the wolf colour phases) from the very start, and the normal colour phase the oddity?
Then I can give you some extra information that goes with what Jaco started with.
COLOR phases have more than just predator issues for game, here is one how will a black sprinbuck's body temp regulating be affected in the Kalahari or Namib, how will his brain temp regulating be influenced?
Predators are but a very small part of this.
Issues, issues, issues..
My best always
In another study on the thermoregulation behaviour of springbok (and in my own field research I observed similar behaviour) it was found that white springbok feed more often than other colour phases (espescially in winter time) and black springbok make use of shade more and feed less than the other colour phases, the study also measured body temperature of the animals they were observing. They then concluded that white springbok have more difficulty keeping their body temperature up since they absorb less heat from the sun and thus to maintain their body temp they have a higher metabolism and accordingly require more food. In the case of the black springbok they absorb so much heat from the sun that they have to start being inactive and utilize shade earlier in the day than the other colours. In my own research my results show that white springbok present their sides to the sun for longer periods than other colour phases so they can absorb max heat from the sun, and interestingly enough the black springbok avoided using the Karoo shrubland (no trees) on the farm entirely during the study period and remained in the Kalahari thornveld part of the farm where there is plenty of shade for them, whilst the white springbok never ventured far from the area where they were provided with lucerne and supplements to feed on.
All you have to do is legislate one child for population control and apparently you can make lots of girl babies disappear!
I would be interested to see if the animals themselves would select the variants as mates or not. They might just reduce themselves naturally.
Hi Brickburn
I initially wanted make this the focus of my study, from what some farmers said (unverified) it seemed that colour did influence sexual selection, unfortunately it was very difficult to study because of the high degree of management on game farms, where only the animals with the desirable traits are allowed to breed whilst the other animals are sold at auction or hunted. So on many occasions just as I thought this or that herd of bachelor springbok are now getting to be a nice size and will soon compete with the dominant males I would go back to the farm for my next period of fieldwork and all of those rams would be gone, leaving no competition for the existing males.
Thanks for all your inputs, I really enjoy it and find that seeing things through different eyes makes one think a bit further than just the obvious stuff.
