Question

When marking an animal for the mark/recapture technique, what can a scientist do to ensure the mark does not lower the organism’s chance of survival, and thus throw off the population estimate?

Answer 1

You should make it unobtrusive to avoid it attracting attention or hindering it in any way. What you can do is shave a small patch of fur from underneath the animal, and this couldn't be noticed by predators from sides but could easily be noticed by a scientist that captures it.