scholarly journals Contrasting trends in gray seal ( Halichoerus grypus ) pup production throughout the increasing northwest Atlantic metapopulation

2020 ◽  
Author(s):  
Cornelia E. Heyer ◽  
W. Don Bowen ◽  
Julian Dale ◽  
Jean‐François Gosselin ◽  
Michael O. Hammill ◽  
...  
Keyword(s):  
Halichoerus Grypus ◽  
Gray Seal ◽  
Northwest Atlantic

scholarly journals Dynamics of the formation of a differentiation track conditioned reflex to sound stimuli of a certain duration in the gray seal Halichoerus grypus Fabricius, 1791 by the methods of operant conditioning.

2021 ◽  
Vol 12 (3-2021) ◽  
pp. 7-13
Author(s):  
A.F. Berdnik ◽  
Keyword(s):  
Reaction Time ◽  
Operant Conditioning ◽  
Conditioned Reflex ◽  
Audio Signal ◽  
Halichoerus Grypus ◽  
Audio Signals ◽  
Gray Seal ◽  
And Behavior ◽  
Sound Duration

In the course of the study, a 15-year-old female gray seal was trained to press a button after displaying an audio signal for 5 seconds and ignore similar audio signals of longer or shorter duration. The conducted research has demonstrated the ability of the experimental seal to reliably differentiate sound signals with a difference in sound duration of 3 seconds. Changes in the reaction time and behavior of the seal during the demonstration of sound stimuli with distinguishable and indistinguishable time ranges are described.

scholarly journals Life cycle bioenergetics of the gray seal (Halichoerus grypus) in the Baltic Sea: Population response to environmental stress

2020 ◽  
Vol 145 ◽  
pp. 106145 ◽  
Author(s):  
Willian T.A.F. Silva ◽  
Karin C. Harding ◽  
Gonçalo M. Marques ◽  
Britt Marie Bäcklin ◽  
Christian Sonne ◽  
...  
Keyword(s):  
Life Cycle ◽  
Environmental Stress ◽  
Baltic Sea ◽  
Halichoerus Grypus ◽  
The Baltic Sea ◽  
Population Response ◽  
Gray Seal ◽  
The Baltic

Direct evidence for gray seal (Halichoerus grypus) predation and scavenging on harbor porpoises (Phocoena phocoena)

2014 ◽  
Vol 30 (4) ◽  
pp. 1542-1548 ◽  
Author(s):  
Thibaut Bouveroux ◽  
Jeremy J. Kiszka ◽  
Michael R. Heithaus ◽  
Thierry Jauniaux ◽  
Sylvain Pezeril
Keyword(s):  
Direct Evidence ◽  
Halichoerus Grypus ◽  
Phocoena Phocoena ◽  
Gray Seal ◽  
Harbor Porpoises

Pup production and population trends of the grey seal (Halichoerus grypus) in the Gulf of St. Lawrence

1998 ◽  
Vol 55 (2) ◽  
pp. 423-430 ◽  
Author(s):  
M O Hammill ◽  
G B Stenson ◽  
R A Myers ◽  
W T Stobo
Keyword(s):  
Population Trends ◽  
Annual Rate ◽  
Halichoerus Grypus ◽  
Grey Seal ◽  
Northwest Atlantic ◽  
Mark Recapture ◽  
Seal Population ◽  
Independent Estimate ◽  
Anticosti Island

Grey seal (Halichoerus grypus) pup production of the Gulf of St. Lawrence component of the Northwest Atlantic grey seal population was determined for the 1984-1986 and 1989-1990 periods using mark-recapture methods. Pup production estimates based on recaptures from shot samples from Anticosti Island ranged from 5436 (SE = 672) to 6955 (SE = 1183) for 1984-1986. An independent estimate for 1984-1986, based on animals captured on Sable Island, was 7431 (SE = 1414) to 8633 (SE = 2827). Mark-recapture estimates of pup production for 1989 and 1990 from shot samples collected from Anticosti Island were 8825 (SE = 3164) and 9156 (SE = 2652), respectively. The estimates based on animals captured on Sable Island varied from 7295 (SE = 2118) to 8116 (SE = 846) for 1989-1990. Both the Anticosti Island and Sable Island recovery samples underestimate 1989 pup production due to hunting which removed 1612 pups from the population before they could disperse. The Gulf component of the Northwest Atlantic grey seal population is increasing at an annual rate of 7.4% (SE = 2.2).

Seasonal variability and individual consistency in gray seal (Halichoerus grypus) isotopic niches

2019 ◽  
Vol 97 (11) ◽  
pp. 1071-1077
Author(s):  
K.M. Hernandez ◽  
A.L. Bogomolni ◽  
J.H. Moxley ◽  
G.T. Waring ◽  
R.A. DiGiovanni ◽  
...  
Keyword(s):  
United States ◽  
Seasonal Variability ◽  
Foraging Ecology ◽  
Population Level ◽  
The United States ◽  
Halichoerus Grypus ◽  
Dietary Specialization ◽  
Gray Seal ◽  
Individual Consistency ◽  
Gray Seals

Although it is often assumed that individuals in generalist populations are equivalent, recent research indicates that individual dietary specialization can be common in marine predators. Gray seals (Halichoerus grypus (Fabricius, 1791)) were considered locally extinct in United States waters by 1958 but have since recolonized the region. Although considered generalists, less is known about gray seal foraging ecology in the United States. To address this, we used carbon and nitrogen stable isotope analyses to investigate the foraging niches of adult gray seals in Massachusetts, USA. We examined skin, fur, and blood components to investigate seasonal variability and individual consistency in foraging niches, and serially sampled vibrissae to quantify the degree of individual foraging specialization in this population. Our results suggest that seals shift from coastal foraging habitats before molt to offshore habitats after molt, with a coincident shift from higher to lower trophic-level prey. Adult gray seals also exhibited individual consistency in foraging niches independent of population-level shifts and reflect a generalist population composed of individual foraging specialists. These findings serve as a baseline for subsequent research on gray seals in United States waters that could help to determine the mechanisms which promote individual specialization in this population.

METAL SENSITIVITY OF MARINE MAMMALS: A CASE STUDY OF A GRAY SEAL (HALICHOERUS GRYPUS)

2006 ◽  
Vol 22 (4) ◽  
pp. 985-996 ◽  
Author(s):  
A. Kakuschke ◽  
E. Valentine-Thon ◽  
S. Fonfara ◽  
S. Griesel ◽  
U. Siebert ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Halichoerus Grypus ◽  
Gray Seal ◽  
Metal Sensitivity

Respiratory properties of blood of the gray seal,Halichoerus grypus

1982 ◽  
Vol 149 (1) ◽  
pp. 49-56 ◽  
Author(s):  
George N. Lapennas ◽  
Robert Blake Reeves
Keyword(s):  
Halichoerus Grypus ◽  
Gray Seal

IMAGING DIAGNOSIS-ULTRASONOGRAPHIC AND CT FINDINGS IN A GRAY SEAL (HALICHOERUS GRYPUS) WITH HEPATIC CIRRHOSIS, PYELONEPHRITIS, AND NEPHROLITHIASIS

2013 ◽  
Vol 54 (5) ◽  
pp. 555-559
Author(s):  
Marie de Swarte ◽  
Jill Bryan ◽  
Micaela Zarelli ◽  
Vihelmiina Huuskonen ◽  
Wilfried Schneeweiss ◽  
...  
Keyword(s):  
Hepatic Cirrhosis ◽  
Halichoerus Grypus ◽  
Imaging Diagnosis ◽  
Gray Seal ◽  
Ct Findings

SERUM BIOCHEMICAL AND HEMATOLOGIC REFERENCE INTERVALS FOR WEANLING NORTHWEST ATLANTIC GRAY SEALS (HALICHOERUS GRYPUS)

2020 ◽  
Vol 51 (1) ◽  
pp. 228
Author(s):  
David D. R. Krucik ◽  
Barbara Mangold ◽  
Wendy Puryear ◽  
Mandy Keogh ◽  
Andrea Bogomolni ◽  
...  
Keyword(s):  
Reference Intervals ◽  
Halichoerus Grypus ◽  
Northwest Atlantic ◽  
Serum Biochemical ◽  
Gray Seals
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