New sightings of false killer whales Pseudorca crassidens (Owen, 1846) in Chile

The gastrointestinal tract of 14 false killer whales, 6 males and 8 females, stranded in June 1995 in southern Brazil, with total standard lengths from 338 to 507 cm, were analysed for endoparasites and food items. A pregnant female had a male foetus of 77.5 cm. Parasites were found in all 14 false killer whales. The nematode Anisakis simplex (Rudolphi, 1809) was found in the stomach of 57% of the animals and the acanthocephalan Bolbosoma capitatum (Linstow, 1889) Porta, 1908 was present in the intestine of all specimens and showed densities up to 600 m-1. An unidentified cestode (Tethrabothridae) was found also in the intestines of 14% of the individuals. The high infections of B. capitatum and A. simplex were not directly related with the cause of death. In the stomachs of four females, beaks of at least eight specimens of the oceanic and epipelagic species Ommastrephes bartramii (Lesueur, 1821) were found, with mantle lengths ranging from 189.8 to 360.9 mm. The distribution of O. bartramii in the coast of Rio Grande do Sul is consistent with false killer whales feeding in continental shelf waters.

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Rare observations of false killer whales (Pseudorca crassidens) cooperatively feeding with common bottlenose dolphins (Tursiops truncatus) in the Hauraki Gulf, New Zealand

Marine Mammal Science ◽

10.1111/j.1748-7692.2012.00582.x ◽

2012 ◽

Vol 29 (3) ◽

pp. 555-562 ◽

Cited By ~ 7

Author(s):

Jochen R. Zaeschmar ◽

Sarah L. Dwyer ◽

Karen A. Stockin

Keyword(s):

New Zealand ◽

Tursiops Truncatus ◽

Bottlenose Dolphins ◽

Killer Whales ◽

Pseudorca Crassidens

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High levels of persistent organic pollutants measured in blubber of island-associated false killer whales (Pseudorca crassidens) around the main Hawaiian Islands

Marine Pollution Bulletin ◽

10.1016/j.marpolbul.2009.08.029 ◽

2009 ◽

Vol 58 (12) ◽

pp. 1932-1937 ◽

Cited By ~ 20

Author(s):

Gina M. Ylitalo ◽

Robin W. Baird ◽

Gladys K. Yanagida ◽

Daniel L. Webster ◽

Susan J. Chivers ◽

...

Keyword(s):

Organic Pollutants ◽

Persistent Organic Pollutants ◽

Hawaiian Islands ◽

Killer Whales ◽

Pseudorca Crassidens

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The abundance of false killer whale, Pseudorca crassidens (Artiodactyla: Delphinidae) in coastal waters of Golfo Dulce and Osa Peninsula, Costa Rica

Revista de Biología Tropical ◽

10.15517/rbt.v68i2.37196 ◽

2020 ◽

Vol 68 (2) ◽

Author(s):

Erika Sánchez Robledo ◽

Lenin Enrique Oviedo Correa ◽

David Herra-Miranda ◽

Juan Diego Pacheco-Polanco ◽

Sierra Goodman ◽

...

Keyword(s):

Costa Rica ◽

Population Size ◽

Killer Whale ◽

Small Population ◽

Killer Whales ◽

Apparent Survival ◽

Osa Peninsula ◽

Small Population Size ◽

False Killer Whale ◽

Pseudorca Crassidens

Introduction: False killer whale (Pseudorca crassidens) is a tropical and subtropical social species that live in groups with individuals of mixed ages and sex classes. False killer whales have been documented since the late 1990s in Southwestern Costa Rica. Objective: To estimate the abundance of false killer whales in Osa Peninsula waters. Methods: Cetacean surveys off the Osa Peninsula Waters (OPW), Costa Rica, yielded opportunistic encounters with false killer whales in Drake Bay and Caño Island (2001-2015) and observations during formal surveys in Golfo Dulce (2005-2015). Photo-identification data was analyzed using capture-mark-recapture models in the study area, through an open population (POPAN) framework, considering the effect of time on the parameters apparent survival and capture probability, producing an abundance estimate for a superpopulation in the entire study area. Results: False killer whale abundance in OPW is characterized by a small population size of no more than 100 individuals, complemented by a very low probability of encounter and a contrasting high apparent survival. Conclusions: This population estimate should be taken as conservative, however, the small population size of less than 100 individuals should be considered vulnerable, in contrast to the increasing anthropogenic impacts in the coastal seascape. We argue the potential occurrence of population units along the coastal seascape of the Pacific littoral and oceanic island-associated units at Isla del Coco.

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