Use of olfaction capabilities of dogs to distinguish faeces of jaguar and puma


Scats are very often the only reliable indicators of the presence of a species, and they can provide a wide array of information about diet, abundance or presence/absence, physical health, stress levels, and parasite loads. Scat analyses provide vital information for management and conservation planning of species in different regions. Many indicators of species abundance and population health are based for a large part on scat surveys.


In simple ecosystems, with single-species occupying each trophic level, scats differ morphologically between levels and their assignment to species is usually not problematic. Difficulties arise where species of concern to conservation have overlapping ranges and similar diets. Jaguar and puma are a prime example, coexisting over much of their geographical range with broadly similar dietary needs, but some differences in favoured prey that may be crucial from a conservation management perspective. Classical methods of distinguishing jaguar from puma scats, based on size, shape and neighbouring footprints (if substrate allows), have proved very unreliable for identifying species. A method that measures the bile acid levels within scats has been used to differentiate jaguars from pumas, but its reliability is no greater than 80%. At present, genetic analysis is the only technique available to distinguish jaguar from puma with certainty. Although reliable, the method is very expensive and has limited success (25-50% of scats) due to degrading of target DNA. The tropical environment of Belize is especially hostile to the DNA in scats taken from the wild, and is likely to result in high failure rates.


Our aim is to test an alternative method that makes use of the extremely powerful olfaction capabilities of dogs to distinguish target species by odour. Dogs are trained on the scats of captive animals fed different diets, and on scats that have been decaying for different periods. Once trained, the dogs can be used on the target scats and can differentiate between species just as a narcotics dog can sniff out particular drugs. The method has already proved successful in distinguishing scats of temperate carnivores (grizzly bears versus black bears and kit foxes versus red foxes and coyotes) but has yet to be tried on tropical carnivores. The tropics contains most endangered species of carnivores, but it also presents special difficulties in terms of the fast rates of decay of scats and the general lack of research funds in tropical regions for running lab-based analyses. The use of dogs potentially has similar reliability to genetic analysis, while being faster and cheaper. Most importantly, it will have potentially a much higher success rate since it relies on overall olfactory pattern, which stays intact longer than the DNA strings required for genetic analysis. Scats retain much of their smell for periods of weeks to months because they are used by carnivores in olfactory communication signals. In addition to identifying species, dogs could potentially distinguish sex and individual.


We intend to validate the method by training the dogs twice for both jaguar and puma and cross-checking different individual dogs. Results will be compared with genetic analysis of a subset of the samples. The method will be applied to an existing sample of ~315 jaguar/puma scats collected from Belize by co-investigator B. Harmsen, representing the largest single collection of its type from one site. Depending on success, the method may open the way for trials on scats of other tropical carnivores, for example the smaller sympatric Ocelot, Margay (Felis wiedii) and Jaguarundi (Herpailurus yaguarondi), for which we have smaller collections. In the longer term, the method has potential applications to Asian carnivores. Field collections of Asian tiger scats have been shown by genetic analysis actually to comprise tigers, dholes and leopards in similar numbers.


This project is funded by the People's Trust for Endangered Species.