Ecological factors that determine distribution and abundance of the California sea lion Zalophus Californianus in the Gulf Of California
The population of the California sea lion Zulophus californianus (Lesson, 1828) in the Gulf of California during the breeding seasons of the 1980’s was estimated at 23,256 individuals, and 31,393 if census adjustments are applied. Of this total (23,256), 6.9% were adult males, 5.0% subadult males, 4...
| Autores: | , |
|---|---|
| Tipo de documento: | artigo |
| Estado: | Versão publicada |
| Data de publicação: | 1994 |
| País: | México |
| Recursos: | UNIVERSIDAD AUTÓNOMA DE BAJA CALIFORNIA |
| Repositório: | Ciencias Marinas |
| Idioma: | inglês |
| OAI Identifier: | oai:cienciasmarinas.com.mx:article/976 |
| Acesso em linha: | https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/976 |
| Access Level: | Acceso aberto |
| Palavra-chave: | California sea lion abundance and distribution population structure operational sex ratio Gulf of California lobo marino abundancia y distribución estructura poblacional proporción sexual golfo de California |
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Ecological factors that determine distribution and abundance of the California sea lion Zalophus Californianus in the Gulf Of California Algunos factores ecológicos que determinan la distribución y abundancia del lobo marino Zalophus californianus, en el Golfo de California |
| title |
Ecological factors that determine distribution and abundance of the California sea lion Zalophus Californianus in the Gulf Of California |
| spellingShingle |
Ecological factors that determine distribution and abundance of the California sea lion Zalophus Californianus in the Gulf Of California Aurioles-Gamboa, D California sea lion abundance and distribution population structure operational sex ratio Gulf of California lobo marino abundancia y distribución estructura poblacional proporción sexual golfo de California |
| title_short |
Ecological factors that determine distribution and abundance of the California sea lion Zalophus Californianus in the Gulf Of California |
| title_full |
Ecological factors that determine distribution and abundance of the California sea lion Zalophus Californianus in the Gulf Of California |
| title_fullStr |
Ecological factors that determine distribution and abundance of the California sea lion Zalophus Californianus in the Gulf Of California |
| title_full_unstemmed |
Ecological factors that determine distribution and abundance of the California sea lion Zalophus Californianus in the Gulf Of California |
| title_sort |
Ecological factors that determine distribution and abundance of the California sea lion Zalophus Californianus in the Gulf Of California |
| dc.creator.none.fl_str_mv |
Aurioles-Gamboa, D Zavala-González, A |
| author |
Aurioles-Gamboa, D |
| author_facet |
Aurioles-Gamboa, D Zavala-González, A |
| author_role |
author |
| author2 |
Zavala-González, A |
| author2_role |
author |
| dc.subject.none.fl_str_mv |
California sea lion abundance and distribution population structure operational sex ratio Gulf of California lobo marino abundancia y distribución estructura poblacional proporción sexual golfo de California |
| topic |
California sea lion abundance and distribution population structure operational sex ratio Gulf of California lobo marino abundancia y distribución estructura poblacional proporción sexual golfo de California |
| description |
The population of the California sea lion Zulophus californianus (Lesson, 1828) in the Gulf of California during the breeding seasons of the 1980’s was estimated at 23,256 individuals, and 31,393 if census adjustments are applied. Of this total (23,256), 6.9% were adult males, 5.0% subadult males, 40.7% adult females, 23.9% juveniles, 22.7% pups (less than one year of age) and 0.8% were termed miscellaneous. Eighty-six percent of the 29 sea-lion colonies studied were on islands, while the remaining colonies occupied capes of the mainland. However, around 98.8% of the sea-lion population was counted on islands. The number of islands (available habitat) did not determine the sea-lion distribution in the gulf, but the concentration of its usual preys (sardine, anchovy, mackerel and hake) did. Eighty-two percent of the sea-lion population and its pup production took place in the northern region of the Gulf of California (from Isla San Esteban northward), which seems to be associated with the major abundance of small pelagic fish in the gulf. California sea lions tend to inhabit small- and medium-sized islands (less than 3 km in length), which amount for 80% of the sea-lion population. The probable factors that determine the selection of islands this size are: 1) the absence of terrestrial predators, 2) easier communication of breeding animals and 3) sexual selection advantage for mating individuals. The operational sex ratio varied according to island size in a negative exponential trend. More adult females were available per adult males on smaller islands, since reduced space clumped the females. This clumping effect enhances a higher male-male competition (with an evident advantage for males), but also a higher quality of territorial males for the breeding females. |
| publishDate |
1994 |
| dc.date.none.fl_str_mv |
1994-03-06 |
| dc.type.none.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Peer-reviewed Article Artículo Arbitrado |
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article |
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publishedVersion |
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https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/976 10.7773/cm.v20i4.976 |
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https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/976 |
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10.7773/cm.v20i4.976 |
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eng |
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eng |
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https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/976/897 |
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info:eu-repo/semantics/openAccess |
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openAccess |
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application/pdf |
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Iniversidad Autónoma de Baja California |
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Iniversidad Autónoma de Baja California |
| dc.source.none.fl_str_mv |
Ciencias Marinas; Vol. 20 No. 4 (1994); 535-553 Ciencias Marinas; Vol. 20 Núm. 4 (1994); 535-553 2395-9053 0185-3880 reponame:Ciencias Marinas instname:UNIVERSIDAD AUTÓNOMA DE BAJA CALIFORNIA instacron:UABC |
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UNIVERSIDAD AUTÓNOMA DE BAJA CALIFORNIA |
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UABC |
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UABC |
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Ciencias Marinas |
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Ciencias Marinas |
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1858177374941609984 |
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Ecological factors that determine distribution and abundance of the California sea lion Zalophus Californianus in the Gulf Of CaliforniaAlgunos factores ecológicos que determinan la distribución y abundancia del lobo marino Zalophus californianus, en el Golfo de CaliforniaAurioles-Gamboa, DZavala-González, ACalifornia sea lionabundance and distributionpopulation structureoperational sex ratioGulf of Californialobo marinoabundancia y distribuciónestructura poblacionalproporción sexualgolfo de CaliforniaThe population of the California sea lion Zulophus californianus (Lesson, 1828) in the Gulf of California during the breeding seasons of the 1980’s was estimated at 23,256 individuals, and 31,393 if census adjustments are applied. Of this total (23,256), 6.9% were adult males, 5.0% subadult males, 40.7% adult females, 23.9% juveniles, 22.7% pups (less than one year of age) and 0.8% were termed miscellaneous. Eighty-six percent of the 29 sea-lion colonies studied were on islands, while the remaining colonies occupied capes of the mainland. However, around 98.8% of the sea-lion population was counted on islands. The number of islands (available habitat) did not determine the sea-lion distribution in the gulf, but the concentration of its usual preys (sardine, anchovy, mackerel and hake) did. Eighty-two percent of the sea-lion population and its pup production took place in the northern region of the Gulf of California (from Isla San Esteban northward), which seems to be associated with the major abundance of small pelagic fish in the gulf. California sea lions tend to inhabit small- and medium-sized islands (less than 3 km in length), which amount for 80% of the sea-lion population. The probable factors that determine the selection of islands this size are: 1) the absence of terrestrial predators, 2) easier communication of breeding animals and 3) sexual selection advantage for mating individuals. The operational sex ratio varied according to island size in a negative exponential trend. More adult females were available per adult males on smaller islands, since reduced space clumped the females. This clumping effect enhances a higher male-male competition (with an evident advantage for males), but also a higher quality of territorial males for the breeding females.El tamaño de la población de lobo marino Zulophus californiunus (Lesson, 1828) en periodo de reproducción, durante la década de los ochenta en el golfo de California, se estimó en un total de 23,256 individuos (sin ajustes) y 31,393 animales, con ajustes al error censal. De estos 23,256, el 6.9% fueron machos adultos, 5% machos subadultos, 40.7% hembras adultas, 23.9% juveniles, 22.7% crías (menores de un año de edad) y 0.8% individuos no clasificados. El 86% de las 29 colonias estudiadas están en islas y el restante en cabos de tierra firme, mientras que el 98.8% de la población total ocupa costa insular. El número de islas (hábitat disponible para la reproducción) no determinó la distribución de la población en el golfo de California. En cambio, la concentración de sus presas habituales (sardina, anchoveta, macarela y merluza) coincide con la abundancia de población: el 82% de la población de lobo marino y la producción de crías del golfo se concentraron en la región norte (de isla San Esteban hacia el norte), lo cual se asocia con la presencia de los grandes cardúmenes de pelágicos menores del golfo. Por otra parte, el lobo marino de California tiende a ocupar islas pequeñas y medianas (menores de 3 km de largo), donde se agrupa el 80% de la población. Los factores que determinan esta selección de tamaño insular pueden ser: 1) ausencia de depredadores terrestres, 2) fácil intercomunicación de los animales para la reproducción y 3) ventaja selectiva para el apareamiento. La razón sexual operativa (número de hembras adultas por cada macho adulto) varió de acuerdo con el tamaño de la isla, en relación exponencial negativa. En promedio, hay más hembras adultas disponibles por macho en las islas pequeñas, debido al efecto de agregación por espacio reducido. Este efecto genera una mayor competencia sexual entre los machos adultos (con evidente ventaja para los mismos), pero también asegura una mejor calidad de los machos territoriales para las hembras reproductoras.Iniversidad Autónoma de Baja California1994-03-06info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionPeer-reviewed Article Artículo Arbitradoapplication/pdfhttps://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/97610.7773/cm.v20i4.976Ciencias Marinas; Vol. 20 No. 4 (1994); 535-553Ciencias Marinas; Vol. 20 Núm. 4 (1994); 535-5532395-90530185-3880reponame:Ciencias Marinasinstname:UNIVERSIDAD AUTÓNOMA DE BAJA CALIFORNIAinstacron:UABCenghttps://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/976/897info:eu-repo/semantics/openAccessoai:cienciasmarinas.com.mx:article/9762024-08-22T17:01:37Z |
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15,811543 |