Published: August 28, 2015

Tea Parties, Bird Barf, and Rat Skulls

Kate Golembiewski, PR and Science Communications Manager, Public Relations

Alert

At tea parties, etiquette is key. You need to know which spoon to use, whether to pour the milk or the tea first, and, when a fellow scientist hands you an owl pellet for your research, how to graciously accept it and dissect it right there at the table.

Field Museum collections manager Bill Stanley was at a garden tea party in Tanzania when a colleague handed him a coffee can containing an owl pellet for him to study. The hacked-up mass of fur and bones contained the key to a scientific discovery—the skull of a rat never before seen in the region.

“I could see a bone, so I started teasing the pellet apart right there in the garden,” said Stanley. “Owls regurgitate the hair and bones from what they eat, and there was a skull that caught my eye immediately—I knew it was a species of Otomys.” It stood out as an Otomys because of its teeth—while many rats have pointed cusps on their teeth, Otomys rats have flat, ridged teeth, like an elephant’s, to grind up plants.

“Looking at the skull, I was wondering, do I have enough to identify the species, and lo and behold, there it was—this was a species of Otomys that wasn’t known from the mountains where the pellet was found.” The rat’s teeth were the key—the combination of orange front teeth and the number of ridges on the molars meant that it could only be Otomys sungae.

The rat species has been documented previously in other regions, but it had never been spotted in the place where this skull had been found. The new location is too far away from its “normal” territory for the owl to have caught the rat there and flown back to this new area to throw it up—the rats must really live there.

Knowing the rat’s range is important because it can help scientists determine a baseline of where the species lives and how it’s being affected by habitat loss. “These mountains are getting hammered left and right, and we only have a small window of time to estimate the baseline that we need to know the exact impacts of agriculture and human development,” explained Stanley. “Until this point, we assumed this species didn’t occur here—if it had gone extinct in this area, we wouldn’t have known that it was there in the first place. Knowing exactly what lives where is vital to understanding how to monitor the health of the ecosystem.”

The fact that the rat is found on mountaintops could also yield some information about how and when species split off from each other as they evolve. “Mountaintops are like islands, and the valleys between them are like the sea. Species living on the tops of mountains are isolated from each other. If we know which species live on which mountain, then we can determine the evolutionary history of the species and track how it got to the mountain originally,” said Stanley.

Stanley is publishing his findings in the Journal of East African Natural History. In his paper, he thanked his friends at the “Kibebe Garden Tea Club” who provided him with tea and the tea party table at which he dissected the owl pellet.

Photos courtesy of Bill Stanley.