When we tag animals so they can be tracked and counted, do the tags affect the way their peers relate to them? Does it affect their mating chances?

  1. It really depends on the species. Those species that depend more heavily on smaller color features are more likely to be affected by bands. It’s an important consideration in the design of bird tracking studies! Here’s an interesting study on zebra finches that found a preference in female individuals for males with red beaks or red identification tags:

  2. Another consideration is how the tag or band might affect their physical movement. For example, with microbats we have to be very careful with radio tags to ensure they don’t substantially impede flight– even if the transmitter only weighs half a gram.

  3. I worked with a group tagging monkeys, and we had to put quite a lot of instrumentation on the poor guys. They were immediately ostracized from the group because of their unfashionable ‘jackets’, but we would capture and release then back into the group no problem in a few days.

  4. Yes! You are absolutely right! Even small tags have shown to affect mortality and breeding rates n penguins in this landmark 2011 study: http://www.nature.com/news/2011/110112/full/news.2011.15.html

  5. A general rule of thumb is to use a tag or collar no heavier than 2-5% of the individuals body weight. Everyone tagging an animal has hopefully considered all possible costs, including a litany of behavioral costs (foraging, interacting with the same species, raising young, etc). interestingly, lots of reptilian or amphibian tags are actually implanted into body cavities (hellbenders, for example: https://ag.purdue.edu/fnr/discover/HerpetologyLab/Documents/StoufferSurgicalImplantation.pdf) or even sewn on to the back of the animal with dissolving sutures (http://www.herpconbio.org/volume1/issue1/Bull2006.pdf). Wildlife biologists often have to resort to these seemingly invasive methods due to the body shape and skin type of reptiles/amphibians. These methods are usually used only when everything else has been ruled out as more damaging or a greater hinderance.

  6. This is something discussed by statisticians as well as biologists when considering what are called capture-recapture methods. You capture some amount of animals, tag them, release them back into their habitat, and then later recapture some new amount and this will give you a good amount of information with which you can make an estimate on how many total animals there are in this habitat.

    Now, what you are asking if whether the tags we place on animals have any effect on their “lifestyle”. Well the answer is: it depends! It definitely can have an effect on the things you mentioned but since we are aware of this we, as statisticians or biologists or what have you, try to minimize the impact of the tags on the animal. It won’t help us estimate the total population if any of the tags go missing unexpectedly (ie: a colorful tag making some animal very visible to predators is bad).

    TL;DR: Yes the tags do affect them but we try to make the tags such that the effect will be minimized.

  7. Not directly related to color, but it was found that certain penguin tags could increase drag when the birds where swimming and hurt their survival chances, source

  8. What about the selective process of capturing animals to tag? A priori I would wager that in general a researcher would be catching less fit individuals. For example, if a researcher is trapping birds, he / she is more likely to trap a sick, unfit bird than a fit, fast, intelligent (and sexually selected) bird.

  9. I was watching a show the other day about tagging lions. They chose to tag & also give a birth control to the lioness, since her male companion would stay with her. What was interesting is that the reason they don’t do the male (for birth control reasons) is that he will lose his mane, therefore losing his stance in the pack.