TY - JOUR
T1 - Immunocontraception decreases group fidelity in a feral horse population during the non-breeding season
AU - Nuñez, Cassandra M.V.
AU - Adelman, James S.
AU - Mason, Carolyn
AU - Rubenstein, Daniel Ian
N1 - Funding Information:
We first acknowledge Dr. Sue Stuska of the Cape Lookout National Seashore, National Park Service, for her data on the Shackleford herd and her assistance with an early version of the manuscript. We also thank M. Hau, S.J. Hauck, C.D. Nadell, I.R. Fischhoff, S.R. Sundaresan, and two anonymous reviewers for their comments and contributions. We would like to acknowledge D. and T. Schooley for their support. This study was funded by the Foundation for Shackleford Horses, Inc. and the National Science Foundation (IIS-0705311 to D. I. Rubenstein).
PY - 2009/2
Y1 - 2009/2
N2 - The behavioral effects of the immunocontraceptive agent porcine zona pellucida (PZP) have not been adequately studied. Important managerial decisions for several species, including the wild horse (Equus caballus), have been based on this limited research. We studied 30 horses on Shackleford Banks, North Carolina, USA to determine the effects of PZP contraception on female fidelity to the harem male. We examined two classes of females: contracepts, recipients of the PZP vaccine (n = 22); and controls, females that have never received PZP (n = 8). We conducted the study during the non-breeding season from December 2005 to February 2006, totaling 102.2 h of observation. Contracepted mares changed groups more often than control mares (P = 0.04). Contracepts also visited more harem groups than did control mares (P = 0.02) and exhibited more reproductive interest (P = 0.05). For both contracepted and control females, the number of group changes (P = 0.01) and number of groups visited (P = 0.003) decreased with the proportion of years mares were pregnant. Our study shows that the application of PZP has significant consequences for the social behavior of Shackleford Banks horses. In gregarious species such as the horse, PZP application may disrupt social ties among individuals and inhibit normal social functioning at the population level.
AB - The behavioral effects of the immunocontraceptive agent porcine zona pellucida (PZP) have not been adequately studied. Important managerial decisions for several species, including the wild horse (Equus caballus), have been based on this limited research. We studied 30 horses on Shackleford Banks, North Carolina, USA to determine the effects of PZP contraception on female fidelity to the harem male. We examined two classes of females: contracepts, recipients of the PZP vaccine (n = 22); and controls, females that have never received PZP (n = 8). We conducted the study during the non-breeding season from December 2005 to February 2006, totaling 102.2 h of observation. Contracepted mares changed groups more often than control mares (P = 0.04). Contracepts also visited more harem groups than did control mares (P = 0.02) and exhibited more reproductive interest (P = 0.05). For both contracepted and control females, the number of group changes (P = 0.01) and number of groups visited (P = 0.003) decreased with the proportion of years mares were pregnant. Our study shows that the application of PZP has significant consequences for the social behavior of Shackleford Banks horses. In gregarious species such as the horse, PZP application may disrupt social ties among individuals and inhibit normal social functioning at the population level.
KW - Behavior
KW - Equus caballus
KW - Harem
KW - Horse
KW - Immunocontraception
KW - Porcine zona pellucidae (PZP)
KW - Stability
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U2 - 10.1016/j.applanim.2008.12.001
DO - 10.1016/j.applanim.2008.12.001
M3 - Article
AN - SCOPUS:58949085327
SN - 0168-1591
VL - 117
SP - 74
EP - 83
JO - Applied Animal Behaviour Science
JF - Applied Animal Behaviour Science
IS - 1-2
ER -