Estimating the isotopic niche of males and females of false killer whales (Pseudorca crassidens ) from Magellan Strait, Chile

2018 ◽  
Vol 35 (3) ◽  
pp. 1070-1082 ◽  
Author(s):  
Daniela Haro ◽  
Luciana Riccialdelli ◽  
Olivia Blank ◽  
Ricardo Matus ◽  
Pablo Sabat
Keyword(s):  
Isotopic Niche ◽  
Killer Whales ◽  
Magellan Strait ◽  
Males And Females ◽  
Pseudorca Crassidens

scholarly journals Gastrointestinal parasites and prey items from a mass stranding of false killer whales, Pseudorca crassidens, in Rio Grande do Sul, Southern Brazil

2001 ◽  
Vol 61 (1) ◽  
pp. 55-61 ◽  
Author(s):  
A. L. V. ANDRADE ◽  
M. C. PINEDO ◽  
A. S. BARRETO
Keyword(s):  
Rio Grande ◽  
Gastrointestinal Parasites ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Ommastrephes Bartramii ◽  
Killer Whales ◽  
Food Items ◽  
Pseudorca Crassidens ◽  
Mass Stranding ◽  
Prey Items

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.

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

2009 ◽  
Vol 58 (12) ◽  
pp. 1932-1937 ◽  
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

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

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.

scholarly journals Intra-population variation in isotopic niche in herring-eating killer whales off Iceland

2017 ◽  
Vol 564 ◽  
pp. 199-210 ◽  
Author(s):  
FIP Samarra ◽  
M Vighi ◽  
A Aguilar ◽  
GA Víkingsson
Keyword(s):  
Population Variation ◽  
Isotopic Niche ◽  
Killer Whales

The underwater whistle repertoire of wild false killer whales (Pseudorca crassidens)

2001 ◽  
Vol 109 (5) ◽  
pp. 2390-2390 ◽  
Author(s):  
A. E. Nester ◽  
J. A. Thomas ◽  
A. Acevedo‐Guiterrez
Keyword(s):  
Killer Whales ◽  
Pseudorca Crassidens

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

2003 ◽  
Vol 38 (2) ◽  
Author(s):  
Marcelo A Flores M ◽  
Rodrigo Moraga ◽  
María José Pérez ◽  
Erika Hanshing ◽  
Carlos Olavarría
Keyword(s):  
Killer Whales ◽  
Pseudorca Crassidens

scholarly journals Isotopic niche differs between seal and fish‐eating killer whales ( Orcinus orca ) in northern Norway

2020 ◽  
Vol 10 (9) ◽  
pp. 4115-4127 ◽  
Author(s):  
Eve Jourdain ◽  
Clare Andvik ◽  
Richard Karoliussen ◽  
Anders Ruus ◽  
Dag Vongraven ◽  
...  
Keyword(s):  
Orcinus Orca ◽  
Isotopic Niche ◽  
Killer Whales ◽  
Northern Norway

Skull morphological variation in a British stranded population of false killer whale (Pseudorca crassidens): a three-dimensional geometric morphometric approach

2022 ◽  
pp. 119-132
Author(s):  
Deborah Vicari ◽  
Richard C. Sabin ◽  
Richard P. Brown ◽  
Olivier Lambert ◽  
Giovanni Bianucci ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Morphological Variation ◽  
Killer Whale ◽  
Three Dimensional ◽  
Anatomical Landmarks ◽  
Geometric Morphometric ◽  
False Killer Whale ◽  
Sexual Shape Dimorphism ◽  
Males And Females ◽  
Pseudorca Crassidens

The false killer whale (Pseudorca crassidens (Owen, 1846)) is a globally distributed delphinid that shows geographical differentiation in its skull morphology. We explored cranial morphological variation in a sample of 85 skulls belonging to a mixed sex population stranded in the Moray Firth, Scotland, in 1927. A three-dimensional digitizer (Microscribe 2GX) was used to record 37 anatomical landmarks on the cranium and 25 on the mandible to investigate size and shape variation and to explore sexual dimorphism using geometric morphometric. Males showed greater overall skull size than females, whereas no sexual dimorphism could be identified in cranial and mandibular shape. Allometric skull changes occurred in parallel for both males and females, supporting the lack of sexual shape dimorphism for this particular sample. Also, fluctuating asymmetry did not differ between crania of males and females. This study confirms the absence of sexual shape dimorphism and the presence of a sexual size dimorphism in this false killer whale population.

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