Abstract # 6225 Event # 249:

Scheduled for Saturday, June 20, 2015 01:15 PM-01:30 PM: (Cascade H) Oral Presentation


INVESTIGATING INFECTION RISK AND SOCIALITY: CENTRALITY INTERACTS WITH SEASONALITY TO PREDICT LICE LOAD IN FREE-RANGING FEMALE JAPANESE MACAQUES, MACACA FUSCATA.

J. Duboscq1,2, V. Romano1,2, C. Sueur1,2,3 and A. MacIntosh4,5
1Université de Strasbourg, Institut Pluridisciplinaire Hubert Curien, Strasbourg 67087, France, 2Centre National de la Recherche Scientifique, Département Ecologie, Physiologie et Ethologie, Strasbourg, France, 3Unit of Social Ecology, Université libre de Bruxelles, Bruxelles, Belgium, 4Kyoto University Primate Research Institute, Inuyama, Japan, 5Kyoto University Wildlife Research Center, Kyoto, Japan
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     Lice are socially-transmitted ectoparasites, and potential vectors of disease. Individuals’ infection risk depends partly upon their degree of contact with others. While grooming facilitates transmission of ectoparasites via body contact, it may constrain the spread of such organisms through removal. Japanese macaques conspicuously pick out louse eggs during grooming, a behavior we used to estimate individual lice load non-invasively. To investigate parasite/disease risk in relation to sociality, we tested the relationship between lice load and contact/grooming centrality with two opposing predictions: i) central individuals harbor more lice because of their numerous social contacts; ii) central individuals harbor fewer lice because of their frequency of being groomed. We studied 20 females of one group in Koshima, Japan. To account for variation in centrality and lice load, we controlled for female dominance rank, her reproductive state, and for season. Results show that centrality interacts with seasonality to predict female lice load (GLMM LRT(full/null): D=57.2, d.f.=9, p<0.001): less central females harbored more lice than others in the mating (winter) and birth (summer) seasons but the relationship reversed during other seasons (e.g., degree:winter-spring = ?±SE=0.47±0.22, z=2.16; degree:winter-summer = ?±SE=-0.14±0.29, z=-0.49; degree:winter-fall = ?±SE=0.45±0.21, z=2.16). We link these results to the parasite and host biology and discuss the relationship between infection risk from socially-transmitted parasites and sociality. Our lice load estimation constitutes a substitute to invasive methods for natural populations.