Abundance and survival estimates of the southeastern Pacific humpback whale stock from 1991–2006 photo-identification surveys in Ecuador

Fernando Félix; Cristina Castro; Jeffrey L. Laake

doi:10.47536/jcrm.vi.303

PDF (English)

Publiée : oct. 22, 2020

DOI : https://doi.org/10.47536/jcrm.vi.303

Fernando Félix

Cristina Castro

Jeffrey L. Laake

Résumé

Southeastern Pacific humpback whales (Breeding Stock G) breed along the northwestern coast of South America and farther north up to Costa
Rica. Photo-identification surveys conducted aboard whalewatching vessels during the migration/breeding season from June to September between
1991 and 2006 off the coast of Ecuador (2°S, 81°W) have produced a database of 1,511 individual whales. Comparisons of photographs produced
190 between-year re-sightings of 155 individual whales. Closed and open capture-recapture models were used to estimate abundance and survival.
The best estimate of abundance in 2006 with the Chapman modified-Petersen was 6,504 (95% CI: 4,270–9,907; CV = 0.21). Abundance estimates
from open population models were considerably lower due to heterogeneity in capture probability which produced a ‘transient’ effect. Our best
estimate of true survival was 0.919 (95% CI: 0.850–0.958). Heterogeneity most likely occurred from inter-annual variation in sampling and unknown
structure and variation in the migration timing and corridor. A more extensive collaborative effort including other wintering areas further north as
well as integrating breeding-feeding data will help to reduce heterogeneity and increase precision in abundance and survival estimates.

Numéro

Humpback Whales: Status in the Southern Hemisphere (Special Issue 3)

Rubrique

Articles

Ce travail est disponible sous licence Creative Commons Attribution - Pas d’Utilisation Commerciale 4.0 International.

You are free to:

Share copy and redistribute the material in any medium or format
Adapt remix, transform, and build upon the material
The licensor cannot revoke these freedoms as long as you follow the license terms.

Under the following terms:

Attribution You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
NonCommercial You may not use the material for commercial purposes.

No additional restrictions You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.

Articles les plus lus par le même auteur ou la même autrice

Fernando Felix, Ben Haase, Claudia Teran, Miguel Pozo, Santiago Burneo, First record of a fin whale (Balaenoptera physalus) in coastal waters of Ecuador in a century , J. Cetacean Res. Manage.: Vol. 23 (2022): JCRM
Fernando Felix, Susana Caballero, Carlos Olavarria, Genetic diversity and population structure of humpback whales (Megaptera novaeangliae) from Ecuador based on mitochondrial DNA analyses , J. Cetacean Res. Manage.: Vol. 12 No 1 (2012): JCRM
Meike Scheidat , Cristina Castro, Janira Gonzalez , Rob Williams , Behavioural responses of humpback whales (Megaptera novaeangliae) to whalewatching boats near Isla de la Plata, Machalilla National Park, Ecuador , J. Cetacean Res. Manage.: Vol. 6 No 1 (2004): JCRM
Fernando Félix, Mercedez Muñoz, Jéssica Falconí, Natalia Botero, Ben Haase, Entanglement of humpback whales in artisanal fishing gear in Ecuador , J. Cetacean Res. Manage.: Humpback Whales: Status in the Southern Hemisphere (Special Issue 3)
Fernando Félix, Daniel M. Palacios, Sandie K. Salazar, Susana Caballero, Ben Haase, Jéssica Falconí, The 2005 Galápagos humpback whale expedition: a first attempt to assess and characterise the population in the Archipelago , J. Cetacean Res. Manage.: Humpback Whales: Status in the Southern Hemisphere (Special Issue 3)
Isabel Avila, Cristina Castro, Short Communication: A novel hypopigmentation for southeast Pacific humpback whales , J. Cetacean Res. Manage.: Vol. 25 (2024): JCRM
Peter T. Stevick, Judith M. Allen, Marcia H. Engel, Fernando Felix, Ben Haase, Mariana C. Neves, Inter-oceanic movement of an adult female humpback whale between Pacific and Atlantic breeding grounds off South America , J. Cetacean Res. Manage.: Vol. 13 No 2 (2013): JCRM
Peter T. Stevick, Anelio Aguayo, Judith Allen, Isabel C. Avila , Juan Capella, Cristina Castro , Kim Chater, Luciano Dalla Rosa, Marcia H. Engel, Fernando Felix, Lilian Florez-Gonzalez , Ana Freitas, Ben Haase, Martha Llano , Liliane Lodi , Edwin Munoz, Carlos Olavarria, Eduardo Secchi, Meike Scheidat , Salvatore Siciliano , Migrations of individually identified humpback whales between the Antarctic Peninsula and South America , J. Cetacean Res. Manage.: Vol. 6 No 2 (2004): JCRM
Jeffrey L. Laake, Andre E. Punt, Gray whale southbound migration surveys 1967–2006: an integrated re-analysis , J. Cetacean Res. Manage.: Vol. 12 No 3 (2012): JCRM
Meike Scheidat, Cristina Castro, Judith Denkinger, Janira Gonz´alez, Dieter Adelung, A breeding area for humpback whales (Megaptera novaeangliae) off Ecuador , J. Cetacean Res. Manage.: Vol. 2 No 3 (2000): JCRM

1 2 > >>

Barre latérale de l'article

Contenu principal de l'article

Résumé

Details de l'article

Articles les plus lus par le même auteur ou la même autrice