TY - JOUR
T1 - Analysis of the re-colonization of San Benito Archipelago by Guadalupe fur seals (Arctocephalus townsendi) = Analisis de la recolonizacion del archipielago de San Benito por el lobo fino de Guadalupe (Arctocephalus townsendi)
AU - Esperon-Rodriguez, Manuel
AU - Gallo-Revnoso, Juan Pablo
PY - 2012
Y1 - 2012
N2 - Exploitation of the Guadalupe fur seal (GFS) during the XVIII and XIX centuries almost extirpated the species. GFS were distributed from the Revillagigedo islands (Mexico) to the gulf of Farallones (USA). At present, reproductive colonies are found at Guadalupe Island and San Benito Archipelago (SBA). The aim of this work was to analyze the process of re-colonization and the current status of GFS at SBA. The first births and the occupation of the west island of the SBA are also reported. Census data from 1997 to 2007 indicated an annual growth rate for the population of 21.6%. The population size, growth tendency of the colony, reproductive biology, and food preferences were also studied. A total of 2,227 GFS were counted at SBA. Three squid species (Loligo opalescens, Onychoteuthis banksii, Dosidicus gigas) were found to be the main dietary components. Territoriality, activity patterns, and reproductive behavior were similar for the seals from Guadalupe Island and SBA. The mean growth rate for pups from SBA was calculated and compared to that of the pups at Guadalupe Island (SBA: 6.7 +_ 1.4 kg, 68.9 +_ 2.64 cm; Guadalupe Island: 5.9 +_ 0.5 kg, 67.29 +_ 4.3 cm). The length of food foraging trips by females was measured, suggesting that the SBA colony is probably near an important feeding area. Maternal care patterns could indicate different strategies of nursing-foraging trips between the SBA and Guadalupe Island. The population of fur seals at SBA is expected to increase as there are no limitations in terms of reproductive space or available food resources in the area.
AB - Exploitation of the Guadalupe fur seal (GFS) during the XVIII and XIX centuries almost extirpated the species. GFS were distributed from the Revillagigedo islands (Mexico) to the gulf of Farallones (USA). At present, reproductive colonies are found at Guadalupe Island and San Benito Archipelago (SBA). The aim of this work was to analyze the process of re-colonization and the current status of GFS at SBA. The first births and the occupation of the west island of the SBA are also reported. Census data from 1997 to 2007 indicated an annual growth rate for the population of 21.6%. The population size, growth tendency of the colony, reproductive biology, and food preferences were also studied. A total of 2,227 GFS were counted at SBA. Three squid species (Loligo opalescens, Onychoteuthis banksii, Dosidicus gigas) were found to be the main dietary components. Territoriality, activity patterns, and reproductive behavior were similar for the seals from Guadalupe Island and SBA. The mean growth rate for pups from SBA was calculated and compared to that of the pups at Guadalupe Island (SBA: 6.7 +_ 1.4 kg, 68.9 +_ 2.64 cm; Guadalupe Island: 5.9 +_ 0.5 kg, 67.29 +_ 4.3 cm). The length of food foraging trips by females was measured, suggesting that the SBA colony is probably near an important feeding area. Maternal care patterns could indicate different strategies of nursing-foraging trips between the SBA and Guadalupe Island. The population of fur seals at SBA is expected to increase as there are no limitations in terms of reproductive space or available food resources in the area.
KW - Guadalupe fur seal
KW - reproductive biology
KW - Mexico
UR - http://handle.westernsydney.edu.au:8081/1959.7/uws:44054
UR - http://www.lajar.cl/pdf/imar/v40n1/Articulo_40_20.pdf
U2 - 10.3856/vo140-issue1-fulltext-20
DO - 10.3856/vo140-issue1-fulltext-20
M3 - Article
SN - 0718-560X
VL - 40
SP - 213
EP - 223
JO - Latin American Journal of Aquatic Research
JF - Latin American Journal of Aquatic Research
IS - 1
ER -