Estimates of Abundance and Trend of Chilean Blue Whales off Isla de Chiloé, Chile

Autor: Bárbara Galletti Vernazzani, Robert L. Brownell, Elsa Cabrera, Carole Carlson, Jennifer A. Jackson
Jazyk: angličtina
Rok vydání: 2017
Předmět:
0106 biological sciences
Male
Databases
Factual
Population Dynamics
lcsh:Medicine
Marine and Aquatic Sciences
Subspecies
Surveys
01 natural sciences
Geographical locations
Predation
Humpback whale
Abundance (ecology)
Chile
lcsh:Science
Balaenoptera musculus
Mammals
education.field_of_study
Multidisciplinary
biology
Animal Behavior
Ecology
Blue Whales
Geography
Population model
Humpback Whales
Research Design
Vertebrates
Physical Sciences
Female
Seasons
Statistics (Mathematics)
Research Article
Population
Gray Whales
Marine Biology
Research and Analysis Methods
010603 evolutionary biology
Confidence Intervals
Animals
14. Life underwater
education
Marine Mammals
Chile (Country)
Behavior
Survey Research
010604 marine biology & hydrobiology
lcsh:R
Organisms
Whales
Biology and Life Sciences
South America
biology.organism_classification
Fishery
Amniotes
Earth Sciences
Antarctica
Balaenoptera
lcsh:Q
Animal Migration
People and places
Zoology
Mathematics
Zdroj: PLoS ONE
PLoS ONE, Vol 12, Iss 1, p e0168646 (2017)
ISSN: 1932-6203
Popis: Since 1970, blue whales (Balaenoptera musculus) have been seen feeding in the waters off southern Chile during the summer and autumn (December to May). Investigation of the genetic, acoustic and morphological characteristics of these blue whales shows that they are a distinct but unnamed subspecies, called the Chilean blue whales. Photo-identification surveys have been conducted in the waters off northwestern Isla Grande de Chiloé, southern Chile from 2004-2012 and Isla Chañaral, central Chile in 2012. Over this time, 1,070 blue whales were encountered yielding, after photo-quality control, 318 and 267 unique photographs of the left and right side of the flank respectively. Using mark-recapture analysis of left and right side photographs collected from Isla Grande de Chiloé (2004-2012), open population models estimate that ~570-760 whales are feeding seasonally in this region. POPAN superpopulation abundance estimates for the same feeding ground in 2012 are 762 (95% confidence intervals, CI = 638-933) and 570 (95% CI 475-705) for left and right side datasets respectively, very similar to results from closed population models. Estimates of trend revealed strong variation in abundance, peaking in 2009 and [suggesting] fluctuating use in the survey area over time, likely related to the density of their prey. High inter-annual return rates suggest a degree of site-fidelity of individuals to Isla Grande de Chiloé and that the number of whales using this feeding ground is relatively small.
Databáze: OpenAIRE
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