scholarly journals Deep-diving by narwhals Monodon monoceros: differences in foraging behavior between wintering areas?

2003 ◽  
Vol 261 ◽  
pp. 269-281 ◽  
Author(s):  
KL Laidre ◽  
MP Heide-Jørgensen ◽  
R Dietz ◽  
RC Hobbs ◽  
OA Jørgensen
Keyword(s):  
Foraging Behavior ◽  
Deep Diving ◽  
Monodon Monoceros ◽  
Wintering Areas

scholarly journals Hunting by the Stroke: How Foraging Drives Diving Behavior and Locomotion of East-Greenland Narwhals (Monodon monoceros)

2021 ◽  
Vol 7 ◽  
Author(s):  
Outi M. Tervo ◽  
Susanne Ditlevsen ◽  
Manh C. Ngô ◽  
Nynne H. Nielsen ◽  
Susanna B. Blackwell ◽  
...  
Keyword(s):  
Foraging Behavior ◽  
Activity Level ◽  
The Arctic ◽  
Foraging Strategies ◽  
Diving Behavior ◽  
Breath Holding ◽  
Excess Oxygen ◽  
East Greenland ◽  
Deep Diving ◽  
Monodon Monoceros

Deep diving air-breathing species by necessity must balance submergence time and level of exercise during breath-holding: a low activity level preserves oxygen stores and allows longer duration submergence whereas high activity levels consume oxygen quickly and shorten submergence time. In this study, we combined high-resolution multi sensor animal-borne tag data to investigate diving behavior and locomotion styles of the narwhal (Monodon monoceros) (n = 13, mean record length 91 h)–a deep diving Arctic species. Narwhals in this study dove down to >800 m but despite the deep diving abilities, one-third of the dives (33%) were shallow (>100 m) and short in duration (<5 min). Narwhals utilized energy saving measures such as prolonged gliding during descent with increasing target depth but stroked actively throughout the ascent indicating excess oxygen storages. Foraging behavior, as detected by the presence of buzzes, was a key factor influencing dive depth and spinning behavior—the rolling movement of the animal along its longitudinal axes. Narwhals in East Greenland utilized two foraging strategies, while transiting and while stationary, with different target depths and buzzing rates. The first targeted deep-dwelling, possibly solitary prey items and the latter, more schooling prey closer to the surface. The buzzing rate during stationary foraging was on average twice as high as during transiting foraging. Spinning was an integrated part of narwhal swimming behavior but the amount of spinning was correlated with foraging behavior. The odds for spinning during all dive phases were 2–3 times higher during foraging than non-foraging. Due to the spinning behavior, stroking rate might be better suited for estimating energy consumption in narwhals than ODBA (overall dynamic body acceleration). The narwhal is considered as one of the most sensitive species to climate change–the results from this study can act as a baseline essential for evaluating changes in the behavior and energy usage of narwhals caused by stressors evolving in the Arctic.

Benthic foraging on seamounts: A specialized foraging behavior in a deep-diving pinniped

2011 ◽  
Vol 28 (3) ◽  
pp. E333-E344 ◽  
Author(s):  
Sara M. Maxwell ◽  
Jessica J. Frank ◽  
Greg A. Breed ◽  
Patrick W. Robinson ◽  
Samantha E. Simmons ◽  
...  
Keyword(s):  
Foraging Behavior ◽  
Deep Diving

Marine Bioluminescence: Measurement by a Classical Light Sensor and Related Foraging Behavior of a Deep Diving Predator

2017 ◽  
Vol 93 (5) ◽  
pp. 1312-1319 ◽  
Author(s):  
Jade Vacquié-Garcia ◽  
Jérôme Mallefet ◽  
Frédéric Bailleul ◽  
Baptiste Picard ◽  
Christophe Guinet
Keyword(s):  
Foraging Behavior ◽  
Deep Diving ◽  
Light Sensor

Summer diet of the narwhal (Monodon monoceros) in Pond Inlet, northern Baffin Island

1982 ◽  
Vol 60 (12) ◽  
pp. 3353-3363 ◽  
Author(s):  
K. J. Finley ◽  
E. J. Gibb
Keyword(s):  
Age Groups ◽  
Stomach Contents ◽  
Late Summer ◽  
Polar Cod ◽  
Greenland Halibut ◽  
Arctic Cod ◽  
Deep Diving ◽  
Monodon Monoceros ◽  
Measured Weight ◽  
Greenland Halibut Reinhardtius Hippoglossoides

Stomach contents of 73 narwhals (Monodon monoceros) taken in Pond Inlet during June to September 1978–1979 were examined. Arctic cod (Boreogadus saida) and Greenland halibut (Reinhardtius hippoglossoides) comprised 51% and 37%, respectively, of the diet by weight. Arctic cod contributed 57% in 1978 but only 29% in 1979. Squid (Gonatus fabricii) beaks were abundant but not representative of recent intake. Deepwater fish (halibut, redfish (Sebastes marinus), and polar cod (Arctogadus glacialis)), found primarily in male narwhals, indicate a deep diving (>500 m) capability. The largest measured weight of stomach contents was 10.1 kg and weights projected from otoliths did not exceed 19.6 kg. No selection of prey items by size was evident amongst various sex and age groups of narwhals. Feeding was most intensive at the ice edge and ice cracks but little feeding took place in the fiords during late summer. Blubber thickness declined in females but not in males during the summer. The significance of traditional summering areas appears to be related to calving requirements and not to feeding opportunities.

Spatial distribution of narwhal (Monodon monoceros) diving for Canadian populations helps identify important seasonal foraging areas

2017 ◽  
Vol 95 (1) ◽  
pp. 41-50 ◽  
Author(s):  
C.A. Watt ◽  
J.R. Orr ◽  
S.H. Ferguson
Keyword(s):  
Satellite Tracking ◽  
The Arctic ◽  
Home Ranges ◽  
Hudson Bay ◽  
Baffin Bay ◽  
Deep Diving ◽  
Monodon Monoceros ◽  
Density Analysis ◽  
Kernel Density Analysis ◽  
Migratory Pathway

In Canada, narwhals (Monodon monoceros L., 1758) are divided into the Baffin Bay (BB) and northern Hudson Bay (NHB) populations. Satellite tracking of 21 narwhals from BB and NHB provided information on their diving behaviour and was used to identify foraging regions. Previous research from hunted narwhals indicated that narwhals in both populations depend on benthic prey to meet their dietary needs. To evaluate home ranges and define areas important for benthic foraging, we conducted kernel density analysis on narwhal locations and focused on areas where deep diving occurs, as a proxy for foraging, in the winter, spring, and migratory periods. These analyses revealed important areas for foraging for BB narwhals on the summer grounds in Eclipse Sound, and the winter grounds in Davis Strait, as well as on the migratory pathway between regions. Similarly, important areas were identified for the NHB narwhal population in northwestern Hudson Bay in summer, in NHB and Hudson Strait on the migration, and to the east of the entrance to Hudson Strait in the winter. This, along with an analysis of the absolute dive depths, provides information on seasons and regions important for foraging, which is particularly relevant with increasing industrial activities in the Arctic.

Foraging behavior of an estuarine predator, the blue crab Callinectes sapidus in a patchy environment

Ecography ◽  
2000 ◽  
Vol 23 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Mary E. Clark ◽  
Thomas G. Wolcott ◽  
Donna L. Wolcott ◽  
Anson H. Hines
Keyword(s):  
Foraging Behavior ◽  
Blue Crab ◽  
Callinectes Sapidus ◽  
Patchy Environment
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