Changes in an Animal’s Behavior After Catch and Release:
Have you ever been on a walk outside and picked up a bug, or a toad, or maybe even a snake? You may have noticed that many of these animals either freeze when you pick them up or try to squirm to get away from you, but have you ever wondered how that animal behaves after you let it go? Does it go back to acting just how it did before you picked it up and handled it? Or is it on a higher alert knowing it might be picked up again so it starts to act differently to make sure that doesn’t happen?
Many scientists learn more about animals by watching and tracking their behavior in the wild, and to do this they have to first catch the animal, place a tracker on it, and then release it and observe its behavior. Researchers have found that when released, certain animals tend to act more or less the same as they did before they were handled, but other animals were seen changing their speeds, the type of activities they do, and the locations they tended to go to after they were released.
But why would certain animals act the same after their release (almost like they forget it happened entirely), and some act extremely differently (like they need to make sure they aren’t caught and handled again)? Researchers have found that animals more used to humans being around them, are a lot less likely to change their behavior after they are released. This means that the toad that lives under your deck, or the turtle in your pond that you see everyday, likely won’t act very differently after you catch them and then let them go. However, animals that are not accustomed to seeing humans regularly will likely change their behavior. For example, if you travel deep into the woods on a hike and happen to find and catch a lizard or a snake, when you let it go, it may try to change its behavior by running/slithering away faster than it usually would, or hiding under leaves for a longer period of time then it generally does.
Knowing that certain species of animals react differently to being handled, and may change their behavior after being released, can help us make sure we aren’t causing unnecessary stress to an animal. It also helps us understand why we may see a change or not see a change in the way certain animals act.
References:
Stiegler, J., Gallagher, C.A., Hering, R. et al. Mammals show faster recovery from capture and tagging in human-disturbed landscapes. Nat Commun 15, 8079 (2024). https://doi.org/10.1038/s41467-024-52381-8
