TY - JOUR
T1 - Plasticity in the agonistic behaviour of male California sea lions, Zalophus californianus
AU - Bohórquez-Herrera, Jimena
AU - Hernández-Camacho, Claudia Janetl
AU - Aurioles-Gamboa, David
AU - Cruz-Escalona, Víctor H.
N1 - Funding Information:
This research was partially funded by the following projects: Mexico's National Council of Science and Technology (Consejo Nacional de Ciencia y Tecnología, CONACyT ; 132415 ), Health, Sustainable Use, and Conservation of the Gulf of California (Estado de salud, uso sustentable y conservación del Golfo de California, RED-IPN) , National Polytechnical Institute (Instituto Politécnico Nacional, IPN ; SIP 1451, 20100911 , 20110297 , 20110299 , 20120061 , 20120069 , 20120363 , 20130402 ); National Commission of Protected Natural Areas (Comisión Nacional de Áreas Naturales Protegidas (CONANP) ): Monitoring the California sea lion (Zalophus californianus californianus) population in reproductive colonies in the Gulf of California and studying their interaction with artisanal fisheries; three study cases (Monitoreo de la población del lobo marino de California (Zalophus californianus californianus) en colonias reproductivas del Golfo de California y estudio de la interacción con las pesquerías artesanales; tres casos de estudio. PROMOBI 2012). J.B.H.'s doctoral research was funded by scholarships from CONACyT, and the Comprehensive Institute Building Program (Programa Integral de Fortalecimiento Institucional, PIFI) from the IPN. The Pacific Naval Force Division of the Mexican Navy (Armada de México–Fuerza Naval del Pacífico of Cabo Cortés) stationed at Cabo Cortés, Baja California, offered invaluable logistical support in the field. We also thank the volunteer field crew from the Burney J. Le Boeuf Pinniped Ecology Lab at CICIMAR-IPN, as well as Nancy Solomon and two anonymous referees for their excellent suggestions on an earlier version of this manuscript. We also thank Dr K. Sullivan for revising the English text.
PY - 2014/3
Y1 - 2014/3
N2 - Environmental conditions may influence mating behaviour in otariids breeding in areas with elevated temperatures and intense solar radiation. Although they have evolved morphological and physiological adaptations to prevent overheating while breeding on land, under extreme temperature conditions, they must adjust their behaviour in order to thermoregulate. The California sea lion mating system is based on male competition and displays that occur while defending their territories when females are present. We studied the agonistic behaviour of adult males at two breeding colonies in Mexico with contrasting environmental characteristics: Isla Santa Margarita (ISM) (Pacific coast) and Isla San Esteban (ISE) (Gulf of California). The goal of this study was to determine which variables influence where (i.e. on land or in the water) aggressive interactions between adult males occurred using logistic regression analysis. We analysed three scenarios: (1) both islands, (2) only ISM and (3) only ISE. The best model for the first scenario included the air temperature, density of females and type of aggression. The second scenario involved the density of females, and the third scenario included the rate of female interactions. Although the California sea lion mating strategy involves monopolizing critical resources, our results indicate that density of females and rate of female interactions have a significant impact on where male aggressive interactions occur. Our results highlight how changing environmental conditions affect the behavioural plasticity of this species' mating system. Most notably, males inhabiting high-temperature environments use the thermoregulatory strategy of defending territories adjacent to the coast while remaining immersed in the water. This strategy may result in decreased polygyny in the Gulf of California colonies relative to those on the Pacific coast.
AB - Environmental conditions may influence mating behaviour in otariids breeding in areas with elevated temperatures and intense solar radiation. Although they have evolved morphological and physiological adaptations to prevent overheating while breeding on land, under extreme temperature conditions, they must adjust their behaviour in order to thermoregulate. The California sea lion mating system is based on male competition and displays that occur while defending their territories when females are present. We studied the agonistic behaviour of adult males at two breeding colonies in Mexico with contrasting environmental characteristics: Isla Santa Margarita (ISM) (Pacific coast) and Isla San Esteban (ISE) (Gulf of California). The goal of this study was to determine which variables influence where (i.e. on land or in the water) aggressive interactions between adult males occurred using logistic regression analysis. We analysed three scenarios: (1) both islands, (2) only ISM and (3) only ISE. The best model for the first scenario included the air temperature, density of females and type of aggression. The second scenario involved the density of females, and the third scenario included the rate of female interactions. Although the California sea lion mating strategy involves monopolizing critical resources, our results indicate that density of females and rate of female interactions have a significant impact on where male aggressive interactions occur. Our results highlight how changing environmental conditions affect the behavioural plasticity of this species' mating system. Most notably, males inhabiting high-temperature environments use the thermoregulatory strategy of defending territories adjacent to the coast while remaining immersed in the water. This strategy may result in decreased polygyny in the Gulf of California colonies relative to those on the Pacific coast.
KW - Agonistic behaviour
KW - Behavioural plasticity
KW - Environmental variation
KW - Female density
KW - Female interaction
KW - Polygynous mating system
KW - Thermoregulation
KW - Zalophus californianus
UR - http://www.scopus.com/inward/record.url?scp=84893377897&partnerID=8YFLogxK
U2 - 10.1016/j.anbehav.2013.12.008
DO - 10.1016/j.anbehav.2013.12.008
M3 - Artículo
SN - 0003-3472
VL - 89
SP - 31
EP - 38
JO - Animal Behaviour
JF - Animal Behaviour
ER -