title: Does home range use explain the relationship between group size and parasitism? A test with two sympatric species of howler monkeys.
abstract: Group size is related to parasite infections in primates. This relationship probably reflects the fact that group size is associated with body contact between group members and with contact with contaminated items in the environment. The latter is highly associated with range use. In the present study we hypothesized that if infection by directly transmitted parasites (DTP) is mainly determined by the exposure of individuals to parasites that accumulate in the environment, and group size correlates negatively with the intensity of home range use, then smaller groups should be more infected by DTP. Additionally, groups that share a higher proportion of their home range with other groups should be more infected. To test our hypothesis we observed and collected fecal samples of two groups of Alouatta palliata (large group size) and two groups of A. pigra (small group size) that live sympatrically in a forest fragment located in Macuspana (Mexico). Group size was positively correlated with range area size and negatively correlated with the intensity of home range use. Range use variables were not related to either DTP prevalence or load. However, there were significant differences in DTP loads between groups, which were positively correlated with group size. Our results suggest that the intensity of home range use is a poor predictor of DTP infection parameters in groups with marked differences in size. Therefore, it is possible that the individual or combined effects of other ecological (e.g., microclimate), social (e.g., contact rate), or physiological (e.g., immune function) factors are more important in the dynamics of DTP in free-ranging primates.
authors: Instituto de Neuroetología, Universidad Veracruzana, Xalapa, Mexico.
authors: Milagros
authors: M
authors: González-Hernández
authors: Pedro Américo D
authors: PA
authors: Dias
authors: Dora
authors: D
authors: Romero-Salas
authors: Domingo
authors: D
authors: Canales-Espinosa
references: Genetics. 2007 Aug;176(4):2421-5
references: 17603105
references: Evolution. 2002 Jan;56(1):177-90
references: 11913662
references: Am J Primatol. 2010 Jun;72(6):539-48
references: 20135692
references: Am J Primatol. 2006 Apr;68(4):397-409
references: 16534810
references: Am J Primatol. 2008 Nov;70(11):1072-80
references: 18666135
references: J Anim Ecol. 2009 Jan;78(1):210-8
references: 19120603
references: Parasitology. 2003 Apr;126(Pt 4):379-88
references: 12741517
references: Conserv Biol. 2006 Apr;20(2):441-8
references: 16903105
references: Nature. 1976 Feb 12;259(5543):459-62
references: 1256543
references: Science. 2000 Nov 10;290(5494):1168-70
references: 11073457
references: Primates. 2010 Jul;51(3):231-9
references: 20224913
references: Am J Phys Anthropol. 2006 Dec;131(4):525-34
references: 16958077
references: Biol Lett. 2006 Sep 22;2(3):351-4
references: 17148401
references: J Wildl Dis. 1990 Oct;26(4):547-9
references: 2250334
references: Am J Primatol. 2005 Oct;67(2):259-66
references: 16229007
references: Nature. 1979 Aug 2;280(5721):361-7
references: 460412
references: Am J Primatol. 2006 Nov;68(11):1089-97
references: 17044010