Androgen and glucocorticoid production in the male killer whale (Orcinus orca): influence of age, maturity, and environmental factors

Andrology ◽  
2016 ◽  
Vol 5 (1) ◽  
pp. 180-190 ◽  
Author(s):  
J. K. O'Brien ◽  
K. J. Steinman ◽  
G. A. Fetter ◽  
T. R. Robeck
Keyword(s):  
Environmental Factors ◽  
Killer Whale ◽  
Orcinus Orca ◽  
Glucocorticoid Production ◽  
Male Killer

scholarly journals A White Killer Whale in the Central Aleutians

ARCTIC ◽  
2009 ◽  
Vol 61 (1) ◽  
pp. 102 ◽  
Author(s):  
Martin Renner ◽  
Kevin Bell
Keyword(s):  
Adult Male ◽  
Killer Whale ◽  
Individual Identification ◽  
Orcinus Orca ◽  
Dorsal Fin ◽  
The North ◽  
North Side ◽  
Bite Mark ◽  
Male Killer

We observed a white adult male killer whale (Orcinus orca) on 7 August 2000 off the north side of Adak Island, Aleutians. An open saddle and a rounded dorsal fin tip suggest that this whale belongs to the fish-eating (“resident”) ecotype. A circular scar matching a cookie-cutter shark (Isistius sp.) bite mark suggested that the animal originated in warmer waters. Photographs and description provided here should enable individual identification should this animal be seen again.

scholarly journals Records of a male killer whale (Orcinus orca) off Southeastern Brazil

2009 ◽  
Vol 57 (1) ◽  
pp. 65-68 ◽  
Author(s):  
Marcos César de Oliveira Santos ◽  
Ednilson da Silva
Keyword(s):  
Killer Whale ◽  
Orcinus Orca ◽  
Southeastern Brazil ◽  
Male Killer

Characterization of male killer whale (Orcinus orca) sexual maturation and reproductive seasonality

2006 ◽  
Vol 66 (2) ◽  
pp. 242-250 ◽  
Author(s):  
T.R. Robeck ◽  
S.L. Monfort
Keyword(s):  
Sexual Maturation ◽  
Killer Whale ◽  
Orcinus Orca ◽  
Reproductive Seasonality ◽  
Male Killer

Basal metabolism of an adult male killer whale (Orcinus orca)

2013 ◽  
Vol 30 (3) ◽  
pp. 1229-1237 ◽  
Author(s):  
Graham A. J. Worthy ◽  
Tamara A. M. Worthy ◽  
Pamela K. Yochem ◽  
Christopher Dold
Keyword(s):  
Adult Male ◽  
Killer Whale ◽  
Basal Metabolism ◽  
Orcinus Orca ◽  
Male Killer

Surface-Based Observations Can Be Used to Assess Behavior and Fine-Scale Habitat Use by an Endangered Killer Whale (Orcinus orca) Population

2016 ◽  
Vol 42 (2) ◽  
pp. 168-183 ◽  
Author(s):  
Dawn P. Noren ◽  
Donna D. W. Hauser
Keyword(s):  
Habitat Use ◽  
Killer Whale ◽  
Orcinus Orca ◽  
Fine Scale

scholarly journals Family feud: permanent group splitting in a highly philopatric mammal, the killer whale (Orcinus orca)

2021 ◽  
Vol 75 (3) ◽  
Author(s):  
Eva H. Stredulinsky ◽  
Chris T. Darimont ◽  
Lance Barrett-Lennard ◽  
Graeme M. Ellis ◽  
John K. B. Ford
Keyword(s):  
Killer Whale ◽  
Group Structure ◽  
Group Living ◽  
Orcinus Orca ◽  
Learning Approaches ◽  
Killer Whales ◽  
Internal Factors ◽  
Individual Fitness ◽  
Leadership Experience

Abstract For animals that tend to remain with their natal group rather than individually disperse, group sizes may become too large to benefit individual fitness. In such cases, group splitting (or fission) allows philopatric animals to form more optimal group sizes without sacrificing all familiar social relationships. Although permanent group splitting is observed in many mammals, it occurs relatively infrequently. Here, we use combined generalized modeling and machine learning approaches to provide a comprehensive examination of group splitting in a population of killer whales (Orcinus orca) that occurred over three decades. Fission occurred both along and across maternal lines, where animals dispersed in parallel with their closest maternal kin. Group splitting was more common: (1) in larger natal groups, (2) when the common maternal ancestor was no longer alive, and (3) among groups with greater substructuring. The death of a matriarch did not appear to immediately trigger splitting. Our data suggest intragroup competition for food, leadership experience and kinship are important factors that influence group splitting in this population. Our approach provides a foundation for future studies to examine the dynamics and consequences of matrilineal fission in killer whales and other taxa. Significance statement Group living among mammals often involves long-term social affiliation, strengthened by kinship and cooperative behaviours. As such, changes in group membership may have significant consequences for individuals’ fitness and a population’s genetic structure. Permanent group splitting is a complex and relatively rare phenomenon that has yet to be examined in detail in killer whales. In the context of a growing population, in which offspring of both sexes remain with their mothers for life, we provide the first in-depth examination of group splitting in killer whales, where splitting occurs both along and across maternal lines. We also undertake the first comprehensive assessment of how killer whale intragroup cohesion is influenced by both external and internal factors, including group structure, population and group demography, and resource abundance.

Captive killer whale ( Orcinus orca ) survival

2015 ◽  
Vol 31 (4) ◽  
pp. 1362-1377 ◽  
Author(s):  
John Jett ◽  
Jeffrey Ventre
Keyword(s):  
Killer Whale ◽  
Orcinus Orca

scholarly journals Visual discrimination learning in the killer whale (Orcinus orca)

1971 ◽  
Vol 3 (4) ◽  
pp. 187-188 ◽  
Author(s):  
Don White ◽  
Paul Spong ◽  
Norm Cameron ◽  
John Bradford
Keyword(s):  
Discrimination Learning ◽  
Visual Discrimination ◽  
Killer Whale ◽  
Orcinus Orca ◽  
Visual Discrimination Learning

Development of intentional stranding hunting techniques in killer whale (Orcinus orca) calves at Crozet Archipelago

1995 ◽  
Vol 73 (1) ◽  
pp. 27-33 ◽  
Author(s):  
Christophe Guinet ◽  
Jérome Bouvier
Keyword(s):  
Growth Curve ◽  
Parental Investment ◽  
Killer Whale ◽  
Elephant Seal ◽  
Orcinus Orca ◽  
Killer Whales ◽  
Juvenile Female ◽  
Adult Females ◽  
Social Transfer ◽  
High Degree

This paper describes the trend in the practice of what we interpret to be the "intentional stranding" hunting technique of two juvenile female killer whales (Orcinus orca), A4 and A5, belonging to pod A on the beaches of Possession Island, Crozet Archipelago. Pod A was composed of three adult females, A2, A3, A6, and one adult male, A1. A2 is A4's mother and A3 is A5's mother. The year of birth and thus the probable age of the two juveniles were estimated from their growth curve determined by means of a photogrammetric technique. These observations indicate that at Crozet Archipelago, juvenile killer whales first practiced intentional stranding on their own when they were 4–5 years old. Their first attempt to capture elephant seal pups by means of this technique was observed when they were 5–6 years old. However, 5- to 6-year-old juveniles still needed the assistance of an adult female to return to the water with their prey. This study indicates that learning hunting techniques needs a high degree of skill and requires high parental investment to reduce the associated risk. Furthermore, social transfer, through apprenticeship, is probably one of the mechanisms that enables the high degree of adaptability observed in killer whales.

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