Rabbits Can Smell Their Dead Relatives in Feces of Predators

A rabbit is pictured on March 28, 2014 in Berlin's Tiergarten park. Rabbits may be able to detect the odors of rabbits in the feces of the ferrets leading them to avoid areas in which their predators roam. JOHANNES EISELE/AFP/Getty Images

European rabbits are the prey of more than 30 different species, so it's not surprising that they have evolved numerous beneficial adaptations and behaviors to help them survive.

Now, researchers have uncovered a particularly bizarre ability that may enable them to avoid getting eaten. According to a paper published in the journal Acta Ethologica, the rodents are capable of recognizing the odor of other rabbits that have been eaten in the feces, or "scats," of predators.

It is well-documented that rabbits recognize the scats of land predators and avoid those areas in which they are present.

But for the latest study, a team of researchers led by José Guerrero-Casado, from the Department of Zoology at the University Córdoba, Spain, wanted to investigate whether rabbits' impressive sense of smell could identify biological traces of other rabbits in predator scats to help identify their locations more efficiently.

"The recognition of [other rabbits] in the predator scats would allow rabbits to avoid those areas with higher risk, feeding in other areas with a lower risk of being predated," Guerrero-Casado told New Scientist.

To find out if this was the case, the researchers conducted an experiment on three plots of land where rabbits lived in the Spanish countryside.

One of the plots was sprayed daily with a neutral smell (water) as a control. Meanwhile, the other two were sprayed with odor extracted from the feces of ferrets that had consumed either rabbit or another mammal (beef).

The researchers counted the number of rabbit pellets left over on the land to determine how often the rabbits were going to the plots to feed. The results showed a lower number of rabbit pellets on those plots containing predator odors than on the control plots.

Furthermore, during the first six days after applying the first odor the number of rabbit pellets was lower on the plots with feces from the ferrets that had eaten rabbit compared to the one where they had consumed beef. However, no differences between the two were recorded nine days after the first odor was applied.

The findings indicate that, in the short term at least, the rabbits may be able to detect the odors of rabbits in the feces of the ferrets leading them to avoid areas in which their predators roam.

"Natural selection has provided animals with mechanisms that enable them to detect predators before being attacked, and this is a new mechanism; less studied, but with great advantages," Guerrero-Casado said.

Previous research has also identified a potentially similar mechanism in other animals. For example, kangaroos and goats have both been reported to avoid areas covered in the feces of tigers that have been eating their brethren.

Looking forward, the researchers hope to determine how exactly the rabbits are able to identify their deceased kin in the feces of the predators.