The life of the river: pee stains or what are you trying to tell me?
Animals, especially mammals, have interesting ways of communicating with each other. I will leave the sophisticated, intricate and often odd Homo sapiens communication to others and instead focus on some of our lesser fellow passengers. Now there are gazillion directions we can go in when discussing mammal communication. The one that I currently find interesting and which you can go out and view yourself in the wonderful winter wonderland is, scent marking.
First some basics. The Oxford Dictionary defines scent marking as: an odoriferous substance containing a pheromone that is deposited by a mammal from a scent gland or in the urine or feces, typically on prominent objects in an area. Scent marking is essentially chemical communication. Dogs, wolves, bears, bobcats, deer, mice all do it. Humans, as a rule, do not. Individuals remember scent mark locations and visit frequently to get the latest news. These scent marks not only provide information about whos territory you are currently entering but also about the health and condition of the animal depositing the scent, information helpful for females looking for a mate. Scent marks are also used for marking trails, as alarm signals and for announcing ones social status.
Otter leave spraints or fecal deposits as scent marks. In addition to the above information, researchers think these spraints are deposited during the commencement of feeding, providing information that someone, in this case an otter, is exploiting the resources in this immediate area so you, another otter, should move on down the line. No need for confrontation, the essential information, this space is currently taken, is provided in the spraint.
As we are all aware during these data rich days, if there is a good source of information, there is someone there to try to exploit it. In an article presented in Ecoscience, Koivula, Viitala & Korpimaki discuss the ability of kestrels and presumably other day-hunting birds of prey to see these scent marks and, furthermore, tell the difference between species of voles and their reproductive status. In their study, they found that the European kestrel preferred scent marks left by mature male voles to females or immature voles. The researchers stated that olfactory cues were unimportant and that kestrels did not react to scent marks in the absence of UV light. Kestrels use these scent marks to locate their preferred food.
As you are out hiking in the great outdoors and you smell or see a scent mark, take a moment to ponder all of the information that is being presented to the world. When you are out walking the dog and he stops to check his pee-mail, let him. There is a lot he can learn about what is going on around the neighborhood.