SCIF has partnered with researchers in Spain to investigate the factors influencing the transmission of maladies like sarcoptic mange (Sarcoptes scabiei) in Iberian ibex (Capra pyrenaica). It appears that seasonal changes in grooming behavior may be highly influential. This research builds on the growing body of knowledge that goes beyond immunity to study the mechanical effect of social behavior in disease transmission. Being free of foreign bodies and particles is termed “neatness.” How grooming affects the rate of colonization by parasites like mange may have population-level impacts for ibex and other species.
The influence of disease and parasites on mammals is a growing field of research and management. Movement of people and animals has created new challenges for managers. Infectious agents can be transported across boundaries that may affect wildlife, livestock or people. Genetic diversity has often been used to explain the differences in susceptibility of individual animals to disease. Similarly, distinct population segments of the same species may experience different rates of infection with pathogens due to population density or geographic barriers keeping segments from interacting regularly. Resistance to disease tends to be greater in populations that have been exposed over a longer period of time and survivors develop a resistance. Significant damage has been shown to occur when naive animals are exposed to novel diseases that they have never faced.
Pathogen transmission obviously increases when animals congregate. Animals that congregate are unknowingly increasing their risk of exposure to parasites and facilitating the spread of bacteria and viruses from one susceptible host to another. One strategy to cope with increased parasite loads is to participate in social grooming (allogrooming) where individuals of the same species remove ecto-parasites such as ticks from other members of the herd. Over the course of generations resistance to diseases will develop and the benefits of herding behavior outweigh the costs, until a new pathogen is introduced. In some species, males and females have significant differences in the density of hair which may influence parasite colonization and ability to groom and other species may have different strategies for coping with parasite loads in a herd situation.
The research supported by SCIF led to the publication of a scientific paper called, “Neatness depends on season, age, and sex in Iberian ibex” published in the journal, Behavioral Ecology in June 2011. The paper described how variables that influence grooming in ibex were experimentally tested. A large part of the analysis described how time of year, age and sex of the animal influence mange infection rate The Conservation Grant provided by SCIF is helping to increase the understanding of, not simply why these mechanisms exist in individual mammals but, how the processes function and the broader implications to the species. The four subspecies of Spanish Ibex are extremely popular with mountain game hunters and these data will help ensure that these populations remain healthy in light of increasing habitat pressures from domestic sheep and goats.