Interspecies Grooming: Zanzibar Red Colobus and Cattle

I have written about interspecies grooming on this blog, a post that appeared sometime last October, Interspecies grooming at The Bronx Zoo. Interspecies grooming first peaked my interest after I realized that two of my cats would readily groom me (hair or skin). Of course, grooming held a special place in my heart. I wrote a thesis comparing grooming behavior in geladas and hamadryas baboons for my undergraduate thesis.

My blog post was featured and I was interviewed for this post on Environmental Graffiti, Monkeys Grooming Other Animals! earlier this October (almost a year after my interspecies blog post appeared). Interspecies grooming can occur among primate groups or among other non-primate groups. There are documented incidents where different primate species or primate and non-primate species (for example ruminants) groom each other. Interspecies grooming is not limited to the natural range of the animals as well. There are also documented bouts of interspecies grooming in captivity, mostly in zoos.

I received an email yesterday from Dr. Katarzyna Nowak, who is affiliated with Wildlife Conservation Research Unit (WildCRU) and the Udzungwa Elephant Project. She sent in a photo of an interspecies grooming in action between a few Zanzibar red colobus (Procolobus kirkii) and a cattle (Bos taurus).

Zanzibar red colobus grooming a calf outside of Jozani-Chwaka Bay National Park.
Photo by Dr. Katarzyna Nowak.

Dr. Nowak later filled me in on this photo.

Hi Raymond, 

The colobus and cows share this environment (it's a farm-field mosaic outside of the national park) so I presume that they compete at least to some extent over herbaceous vegetation as the colobus are largely terrestrial here. But it is only once that I observed this behavior (I was with primatologists Tom Struhsaker and Andy Marshall when we saw this) and I don't know of anyone else who has seen it before or since...but again, I imagine it happens more often. 

Interspecies grooming is a very fascinating interaction, at least to me. I think that it is easier to document interspecies grooming than to tease out why this behavior exist between individuals. But of course, each interaction is probably unique between the groomer and the one being groomed. I have wondered whether interspecies grooming in captivity is due to boredom. But of course I have no way of testing these hypotheses given that it's quite hard to proof that an animal is "bored". There are, of course, some ingenious ways out there to find out what these animals are thinking.

Please feel free to discuss or tell me why you think interspecies grooming occur and what types of studies can be used to further elucidate this phenomenon. Seen an interspecies grooming in action? Feel free to email me and tell me all about it. Emails with pictures will get a cookie!