Seasonal variation in the abundance of South American sea lions Otaria flavescens (Shaw, 1800) in Chañaral Island, Reserva Nacional Pingüino de Humboldt, Chile

Sepúlveda, Maritza; Inostroza, Patricia; Pérez‐Álvarez, María José; Oliva, Doris; Moraga, Rodrigo

doi:10.4067/s0718-19572009000300014

Cited by 8 publications

(11 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The population at PP is probably found in a survival phase extending from the cessation of human exploitation and to the initiation of breeding activities (Roux 1987, Grandi et al 2008. In this context, although the presence of pups was already reported in this colony, it still does not show the typical monthly and seasonal patterns of the breeding colonies (Acevedo et al 2003, Pavés et al 2005, Sepúlveda et al 2009, and therefore the classification of breeding and non-breeding colonies should be reviewed (Crespo 1988). As established by Grandi et al (2008) in SASL colonies from the Atlantic coast, the structural and compositional changing process of a colony (from non-breeding to breeding) begins with the establishment of juveniles followed by the incorporation of adult males, subadult males, or both, which yields mixed composition colonies.…”

Section: Monthly Variations In Abundancementioning

confidence: 90%

“…Surveys were performed in February, because this month represents the peak of the breeding season for the SASL in the Chilean coast, when most individuals are present at the rookery for reproduction, and almost all pups are already born (Acevedo et al 2003, Sepúlveda et al 2009, 2012. For each survey, and during 3 consecutive days, colonies were photographed.…”

Section: Population Surveys Of South American Sea Lions Annual Fluctumentioning

confidence: 99%

“…Females on the other hand remain with their pups in the colony, alternating their time between pup attendances on land and foraging trips to the ocean (Campagna & LeBoeuf 1988, Muñoz et al 2011. During the rest of the year (April to December), sea lions of all ages and sex classes can be seen in the rookeries, although the number of sea lions hauled-out vary considerably in different months (Sepúlveda et al 2009(Sepúlveda et al , 2012. Thus, breeding season constitutes a strong component influencing haul-out patterns on this species.…”

Section: Introductionmentioning

confidence: 97%

See 2 more Smart Citations

Annual, seasonal and daily variation in the abundance of the South American sea lion Otaria flavescens in two breeding colonies in northern Chile

Sepúlveda

Santos

Veas³

et al. 2015

Rev. biol. mar. oceanogr.

Self Cite

View full text Add to dashboard Cite

ARTICLE Annual, seasonal and daily variation in the abundance of the South American sea lion Otaria flavescens in two breeding colonies in northern ChileVariaciones anuales, estacionales y diarias en la abundancia del lobo marino común Otaria flavescens en dos colonias reproductivas del norte de Chile Resumen.-Los estudios de variaciones de abundancia de las poblaciones a distintas escalas temporales permi ten comprender cómo dichas poblaciones fluctúan en el tiempo y cuáles son los factores que influyen sobre dichas variaciones. Se analizaron los patrones de abundancia del lobo marino común (SASL, Otaria flavescens) a escalas diaria, mensual y anual en 2 loberas reproductivas del norte de Chile. Adicionalmente, se evaluó el efecto de El Niño sobre los patrones anuales de la especie. La abundancia de lobos marinos en Punta Negra (PN) disminuyó desde 1994 a 2011, mientras que en Punta Patache (PP) aumentó, aunque el número de crías fue proporcionalmente bajo. Los resultados demuestran un efecto importante de El Niño sobre la abundancia de lobos marinos, especialmente para hembras + juveniles en PN. La abundancia mensual de hembras y juveniles fue mayor en invierno, mientras que para machos adultos y subadultos no se encontró ningún patrón. Finalmente, durante el día la abundancia incrementa hasta llegar a un máximo hacia fines de la tarde, especialmente en el caso de hembras y juveniles. No se encontraron diferencias en los patrones de abundancia entre las épocas reproductiva y no reproductiva para ninguna de las clases de sexo/edad. Este estudio muestra que la abundancia en PP y PN muestra peri odicidades anuales, mensual es y diarias, y que dichas periodicidad es están condicionadas tanto por factores intrínsecos (e.g., época reproductiva) como extrínsecos (e.g., hora del día, El Niño). A escala anual, los resultados indican que aún a una escala local, las tendencias de abundancia en 2 c olonias pueden ser diferentes. Maritza Palabras clave: Circaritmos, actividad en tierra, Otaria byroniaAbstract.-Studies on population abundance variations at different temporal scales contribute to the understanding on how these populations change over time and what are the factors influencing those variations. We analyzed daily, monthly and annual haul-out abundance patterns of South American sea lions (SASL, Otaria flavescens) in 2 breeding colonies of the north of Chile. Additionally we analyzed the effect of El Niño events on the sea lions' annual patterns. The abundance of sea lions in Punta Negra (PN) decreased from 1994 to 2011, whereas in Punta Patache (PP) increased, although the number of pups was proportionately low. Our results indicated a strong effect of El Niño over the abundance of sea lions, especially for females + juveniles in PN. The haul-out monthly abundance of females and juveniles increased during austral winter months, whereas adult and subadult males did not show a clear pattern. Finally, the haul-out abundance tended to increase throughout the day reaching a maximum by late afternoon, especially for ...

show abstract

Section: Monthly Variations In Abundancementioning

confidence: 90%

Section: Population Surveys Of South American Sea Lions Annual Fluctumentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

See 1 more Smart Citation

Annual, seasonal and daily variation in the abundance of the South American sea lion Otaria flavescens in two breeding colonies in northern Chile

Sepúlveda

Santos

Veas³

et al. 2015

Rev. biol. mar. oceanogr.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The island is about 10 km from the coast; the sea lion colony is located in the protected zone which extends from the island to the continent. During the summer, this colony is composed of approximately 850 individuals, about 70% of which are concentrated in the reproductive area of the colony (Sepúlveda et al 2009). Most of the individuals in the nonreproductive area are sub-adult males, old males and juveniles who do not participate in reproduction.…”

Section: Methodsmentioning

confidence: 99%

“…Tourists also observe a diverse species of birds which nest on the island, such as the Humboldt penguin (Spheniscus humboldtii), Peruvian booby (Sula variegata) and Dominican gull (Larus dominicanus) (Simeone et al 2003). Additionally, tourists observe the pinniped colonies which inhabit the island, principally the South American sea lion (Otaria flavescens), and to a lesser degree some phocids, such as the southern elephant seal (Mirounga leonina) (Sepúlveda et al 2007(Sepúlveda et al , 2009). In particular, the reproductive colony of the South American sea lion on the island is a great tourist attraction, due to its easy access and to the fact that the peak tourism period coincides with the reproductive period of the species, in which there is a high animal abundance and newborn pups (Acevedo et al 2003, Pavés et al 2005, Sepúlveda et al 2009).…”

Section: Pavez Et Almentioning

confidence: 99%

Behavioral response of South American sea lion Otaria flavescens to tourist disturbance during the breeding season

Pavez¹,

Muñoz²,

Inostroza³

et al. 2011

Rev. biol. mar. oceanogr.

Self Cite

View full text Add to dashboard Cite

Resumen.-Los pinípedos muestran una alta predictibilidad en su distribución, tanto espacial como temporal, y tienden a congregarse en parches, lo que permite un fácil acceso de turistas. Sin embargo, la presencia de dichos turistas puede generar un impacto negativo sobre los animales. El objetivo de este estudio fue evaluar, por primera vez en Chile, el efecto del ecoturismo sobre el comportamiento del lobo marino común Otaria flavescens durante la época reproductiva. Registramos un total de 44 visitas de embarcaciones a la lobera reproductiva de Isla Chañaral. La mayoría de los turistas mostró una actitud de calma, seguida por moderada y perturbadora. La respuesta de los lobos marinos fue mayoritariamente de escape, seguida de inactiva y alerta. La respuesta de los lobos marinos se relacionó negativamente con la distancia de aproximación de la embarcación a la colonia, pero no se relacionó ni con el tiempo de permanencia de la embarcación en la colonia ni con la conducta de los turistas. Nuestros resultados indican que el lobo marino común es afectado negativamente por la presencia de turistas, especialmente debido al escape de los individuos desde la colonia al mar. Dichos escapes pueden generar efectos fisiológicos negativos sobre el animal, lo que puede incidir sobre su adecuación biológica. Sugerimos que futuros estudios evalúen el comportamiento de respuesta de los lobos marinos durante la época reproductiva y en otros periodos del año, además de analizar posibles diferencias entre clases de edad y sexo, lo que permita contar con herramientas adecuadas para el manejo del turismo sobre el lobo marino común en Chile. Palabras clave: Comportamiento animal, ecoturismo, manejo, pinípedos, ChileAbstract.-Pinnipeds have a high predictability, both spatial and temporal, and tend to be distributed in patches, which permitting tourists easy access to them. However, the presence of tourists may generate a negative impact on the animals. The objective of this study was to evaluate, for the first time in Chile, the effect of ecotourism activities on the behavior of the South American sea lion Otaria flavescens during the reproductive season. We recorded a total of 44 visiting boats to the reproductive colony of this species on Isla Chañaral. The attitude of the majority of the tourists was a quiet one; however this was followed by moderate and disturbing behavior. The response of sea lions was mainly to escape, followed by a period of inactive and alert. The response of sea lions was negatively related to the distance at which the boats approached the colony, but was not related to the time boats remained in the colony or the behavior of tourists. Our results show that the South American sea lion is negatively affected by human presence, shown by the escape of individuals from the colony to the sea. Escaping from the colony may generate negative physiological effects on an animal physiological effects on an animal, and ultimately affect the fitness of the individual. We suggest that future studies should evaluate chang...

show abstract

Long‐term abundance dynamics of the South American sea lion (Otaria flavescens) in the most important breeding colony in central Chile

2021

Self Cite

View full text Add to dashboard Cite

Long-term studies that monitor changes in the abundance of pinnipeds are particularly relevant given that these long-lived species are considered to be indicators of the quality of the ecosystems around them. We report a continuous record of the total abundance by sex and age-classes of the South American sea lion (Otaria flavescens) in Cobquecura, the most important breeding colony in central Chile over a twelve-year period (2008 to 2020). We also analysed the demographic trends in South American sea lion abundance at this location. A total of 110 and 43 sea/land based and aerial censuses were performed over the studied period, respectively. The number of sea lions on land was highest in the summer months, which corresponds to the breeding season of the species. The abundance ranged from a minimum of 870 to a maximum of 4,531 individuals from sea/landbased observations, and from 796 to 4,854 from aerial censuses. This variation was mainly influenced by the number of adult females, the most abundant age-class in the colony. On the contrary, adult and sub-adult males were least abundant in the population. The highest numbers of pups were registered in February of each year, ranging from 448 in February 2009 to 1,214 in February 2017. During the study period, we estimated a finite growth rate (k) of 1.031, suggesting an increase in the population size in the colony, especially in the number of pups. Considering Cobquecura is highly susceptible to anthropogenic disturbance, developing effective longterm protection through adequate management is critical to better conserve the South American sea lion in the most important breeding colony in central Chile.

show abstract

Seasonal variation in the abundance of South American sea lions Otaria flavescens (Shaw, 1800) in Chañaral Island, Reserva Nacional Pingüino de Humboldt, Chile

Cited by 8 publications

References 15 publications

Annual, seasonal and daily variation in the abundance of the South American sea lion Otaria flavescens in two breeding colonies in northern Chile

Annual, seasonal and daily variation in the abundance of the South American sea lion Otaria flavescens in two breeding colonies in northern Chile

Behavioral response of South American sea lion Otaria flavescens to tourist disturbance during the breeding season

Long‐term abundance dynamics of the South American sea lion (Otaria flavescens) in the most important breeding colony in central Chile

Contact Info

Product

Resources

About