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Full-Text Articles in Life Sciences

Linking Social Behavior And Stress Physiology In Feral Mares (Equus Caballus): Group Transfers Elevate Fecal Cortisol Levels, Cassandra M.V. Nuñez, James S. Adelman, Jessica Smith, Laurence Gesquiere, Daniel I. Rubenstein Jan 2014

Linking Social Behavior And Stress Physiology In Feral Mares (Equus Caballus): Group Transfers Elevate Fecal Cortisol Levels, Cassandra M.V. Nuñez, James S. Adelman, Jessica Smith, Laurence Gesquiere, Daniel I. Rubenstein

Cassandra M.V. Nuñez

Feral horses (Equus caballus) have a complex social structure, the stability of which is important to their overall health. Behavioral and demographic research has shown that decreases in group (or band) stability reduce female fitness, but the potential effects on the physiological stress response have not been demonstrated. To fully understand how band stability affects group-member fitness, we need to understand not only behavioral and demographic, but also physiological consequences of decreases to that stability. We studied group changes in feral mares (an activity that induces instability, including both male and female aggression) on Shackleford Banks, NC. We found that …


A Free-Ranging, Feral Mare Equus Caballus Affords Similar Maternal Care To Her Genetic And Adopted Offspring, Cassandra M.V. Nuñez, James S. Adelman, Daniel I. Rubenstein Nov 2013

A Free-Ranging, Feral Mare Equus Caballus Affords Similar Maternal Care To Her Genetic And Adopted Offspring, Cassandra M.V. Nuñez, James S. Adelman, Daniel I. Rubenstein

Cassandra M.V. Nuñez

Adoption of nongenetic offspring occurs in a variety of species but is rare in equids. We report a case of adoption by a free-ranging, feral mare Equus caballus and compare the maternal care received by her genetic offspring (born 1995) to that of her adopted offspring (born 1996) for the first 30 weeks of development. We compare five measures of care: (1) total time spent suckling, (2) mare aggression during suckling, (3) number of mare-terminated suckling bouts, (4) contact maintenance, and (5) mare-foal distance. For most behaviors, we detected no difference in the mare’s treatment of the two foals; however, …


Does Immunocontraception In Feral Horses (Equus Caballus) Extend Reproductive Cycling Beyond The Normal Breeding Season?, Cassandra M.V. Nuñez, James S. Adelman, Daniel I. Rubenstein Jan 2012

Does Immunocontraception In Feral Horses (Equus Caballus) Extend Reproductive Cycling Beyond The Normal Breeding Season?, Cassandra M.V. Nuñez, James S. Adelman, Daniel I. Rubenstein

Cassandra M.V. Nuñez

Although the physiological effects of immunocontraceptive treatment with porcine zona pellucida (PZP) have been well studied, little is known about PZP’s effects on the scheduling of reproductive cycling. Recent behavioral research has suggested that recipients of PZP extend the receptive breeding period into what is normally the non-breeding season. To determine if this is the case, we compiled foaling data from wild horses (Equus caballus) living on Shackleford Banks, North Carolina for 4 years pre- and 8 years post-contraception management with PZP (pre-contraception, n = 65 births from 45 mares; post-contraception, n = 97 births from 46 mares). Gestation lasts …


Immunocontraception In Wild Horses (Equus Caballus) Extends Reproductive Cycling Beyond The Normal Breeding Season, Cassandra M.V. Nuñez, James S. Adelman, Daniel I. Rubenstein Oct 2010

Immunocontraception In Wild Horses (Equus Caballus) Extends Reproductive Cycling Beyond The Normal Breeding Season, Cassandra M.V. Nuñez, James S. Adelman, Daniel I. Rubenstein

Cassandra M.V. Nuñez

Although the physiological effects of immunocontraceptive treatment with porcine zona pellucida (PZP) have been well studied, little is known about PZP's effects on the scheduling of reproductive cycling. Recent behavioral research has suggested that recipients of PZP extend the receptive breeding period into what is normally the non-breeding season. To determine if this is the case, we compiled foaling data from wild horses (Equus caballus) living on Shackleford Banks, North Carolina for 4 years pre- and 8 years post-contraception management with PZP (pre-contraception, n = 65 births from 45 mares; post-contraception, n = 97 births from 46 mares). Gestation lasts …


Behavioral Effects Of Contraception Management: The Use Of Porcine Zona Pellucida On Wild Horses, Cassandra M.V. Nuñez Jan 2008

Behavioral Effects Of Contraception Management: The Use Of Porcine Zona Pellucida On Wild Horses, Cassandra M.V. Nuñez

Cassandra M.V. Nuñez

The advent of immunocontraception with porcine zona pellucida (PZP) has all but revolutionized wild horse management, providing a more humane method of population control than earlier strategies. Early studies on Assateague Island National Seashore have described it as an ideal form of fertility control in that it reduces the chance of conception to below 10%, can be delivered remotely, is reversible (after short-term use), lacks debilitating physiological side effects, cannot pass through the food chain, and shows minimal effects on social behaviors. However, recent research in other populations has revealed behavioral and physiological side effects of long-term PZP use. These …