Doing research with camera traps is a lot of fun, because you capture things that you would not have expected beforehand. Last month my fieldwork started with the placement of cameras in different forested areas in the Netherlands to look at the interaction between species diversity and tick densities and the infection of ticks with Borrelia burgdorferi s.l., the causative agent of Lyme disease. I do not use any bait or lure to draw the animals towards my camera, as I want to use the number of photos I take from each species as a measurement of their density. Therefore, the animals that walk in front of my camera display ‘regular’ behaviour and most of them just walk by.
However, some of the animals show special behaviour, like the roe buck in this picture. It is marking its territory with the scent glands on its head at 7:34 pm, and walks on. About 45 minutes later, a red fox walks past, it stops, and it sniffs the tree, which was just marked by the roe buck. Apparently, these scent cues are not only to let other members of your species know that you are there and that this is your territory, but it also works to let the neighbours know you are there. Even if the neighbours are from a different species.