scholarly journals Use of the Alaskan Beaufort Sea by Bowhead Whales (Balaena mysticetus) Tagged with Satellite Transmitters, 2006 – 18

ARCTIC ◽  
2020 ◽  
Vol 73 (3) ◽  
pp. 278-291
Author(s):  
Justin Olnes ◽  
John J. Citta ◽  
Lori T. Quakenbush ◽  
John C. George ◽  
Lois A. Harwood ◽  
...  
Keyword(s):  
Satellite Telemetry ◽  
State Space Model ◽  
Beaufort Sea ◽  
Bowhead Whale ◽  
Movement Behavior ◽  
Autumn Migration ◽  
Bowhead Whales ◽  
Dive Behavior ◽  
Satellite Transmitters ◽  
Switching State

We used satellite telemetry to examine bowhead whale movement behavior, residence times, and dive behavior in the Alaskan Beaufort Sea, 2006 – 18. We explored the timing and duration of use of three subregions (western, central, eastern) within the Alaskan Beaufort Sea and applied a two-state switching state-space model to infer bowhead whale behavior state as either transiting or lingering. Transiting whales made direct movements whereas lingering whales changed direction frequently and were presumably feeding. In spring, whales migrated across the Alaskan Beaufort Sea in 7.17 ± 0.41 days, primarily off the continental shelf over deep water. During the autumn migration, whales spent over twice as much time crossing the Alaskan Beaufort Sea than in spring, averaging 18.66 ± 2.30 days, spending 10.05 ± 1.22 days in the western subregion near Point Barrow. Most whales remained on the shelf during the autumn migration and frequently dove to the seafloor, where they spent 45% of their time regardless of behavioral state. Consistent dive behavior in autumn suggests that the whales were looking for food while migrating, and the identification of lingering locations likely reflects feeding. The lack of lingering locations in the eastern and central subregions suggests that prey densities are rarely sufficient to warrant whales pausing their migration for multiple days, unlike in the western subregion near Point Barrow, where bowhead whales regularly lingered for long periods of time.

Effectiveness of acoustic localization in documenting spatial and temporal patterns in autumn migration of bowhead whales in the Alaskan Beaufort sea

2004 ◽  
Vol 116 (4) ◽  
pp. 2588-2588
Author(s):  
Susanna B. Blackwell ◽  
Robert G. Norman ◽  
Charles R. Greene ◽  
Miles W. McLennan ◽  
Trent L. McDonald ◽  
...  
Keyword(s):  
Temporal Patterns ◽  
Beaufort Sea ◽  
Autumn Migration ◽  
Spatial And Temporal Patterns ◽  
Acoustic Localization ◽  
Bowhead Whales

Satellite-monitored movements of radio-tagged bowhead whales in the Beaufort and Chukchi seas during the late-summer feeding season and fall migration

2000 ◽  
Vol 78 (7) ◽  
pp. 1168-1181 ◽  
Author(s):  
Bruce R Mate ◽  
Gregory K Krutzikowsky ◽  
Martha H Winsor
Keyword(s):  
Shallow Water ◽  
Late Summer ◽  
Open Water ◽  
Beaufort Sea ◽  
River Delta ◽  
Bowhead Whale ◽  
Balaena Mysticetus ◽  
Bowhead Whales ◽  
Russian Waters ◽  
Summer Feeding

From 30 August to 6 September 1992, we tagged 12 juvenile bowhead whales (Balaena mysticetus) with Argos satellite-monitored radio tags in the Canadian Beaufort Sea off the Mackenzie River Delta. Eight tags documented [Formula: see text]9820 km of movements between 392 locations during 111 whale-tracking days. The whales did not move in unison. Individual movements and average speeds (1.1-5.8 km/h) varied widely. One whale stayed in Mackenzie Bay for 23.5 d, while the rest stayed an average of only 2.4 d. The majority of locations for all whales were in shallow water: 65% at <50 m depth and 87% at <100 m depth. Seven whales went into water >100 m deep and four were in water >500 m deep. The whale with the longest record traveled [Formula: see text]3886 km to Siberia in 32.5 d, averaging 5.0 km/h. Its westerly route through the Beaufort and Chukchi seas was between 70° and 72°N and primarily in heavy ice ([Formula: see text]90% coverage), which was continuous west of 151°W. This whale's speed was faster, though not significantly, in heavy ice than in more open water. This is the first detailed documentation of the route and speed of a bowhead whale during its fall migration from Canadian to Russian waters.

scholarly journals Observations of Beachcast Bowhead Whales (Balaena mysticetus) in the Southeastern Beaufort Sea and Amundsen Gulf, 1987–2016

2018 ◽  
Vol 131 (3) ◽  
pp. 270-279
Author(s):  
Lois A. Harwood ◽  
Ellen V. Lea ◽  
Stephen A. Raverty ◽  
Patricia A. Hall ◽  
Erin Linn ◽  
...  
Keyword(s):  
Beaufort Sea ◽  
Bowhead Whale ◽  
Grizzly Bears ◽  
Balaena Mysticetus ◽  
Adult Group ◽  
Mature Adult ◽  
Bowhead Whales ◽  
Mature Adults ◽  
Amundsen Gulf ◽  
Summer Feeding

Each spring, most Bowhead Whales (Balaena mysticetus) of the Bering-Chukchi-Beaufort (BCB) population migrate to the Canadian Beaufort Sea and Amundsen Gulf for summer feeding. Occasionally, Inuvialuit hunters and others observe beachcast (stranded) or adrift Bowhead Whale carcasses. From 1987 to 2016, 26 such occurrences were recorded. Most (65%) were found by Inuvialuit hunters travelling on the land, with the majority (54%) reported during 2000–2006. Bowhead Whale carcasses were found widely distributed throughout the region, with twice as many in Amundsen Gulf (65%) compared with the southeastern Beaufort Sea (35%). It was possible to measure or estimate standard length for 17 of 26 specimens, and all were either provisional ‘subadults’ (7–9.5 m; n = 10; 59%) or provisional ‘mature adults’ (13–16 m; n = 7; 41%). The cause(s) of mortality was not determined for any of the specimens. Whales in the ‘subadult’ group were likely 1–4 years old, while the ‘mature adult’ group were likely mostly mature animals (~25 y), including some potentially very old (>100 y). There was evidence or direct observation of Polar Bears (Ursus maritimus) and/or Grizzly Bears (U. arctos) scavenging at 60% of the carcasses for which presence or absence of bears or bear sign (scats and/or tracks) was reported. It is important to continue to record incidental observations of beachcast Bowhead Whales, as this may enable stranding rates to be evaluated.

scholarly journals Newly Discovered migratory corridor and foraging ground for Atlantic green turtles, Chelonia mydas, nesting on Bioko Island, Equatorial Guinea

2019 ◽  
Author(s):  
Emily Mettler ◽  
Chelsea E. Clyde-Brockway ◽  
Shaya Honarvar ◽  
Frank V. Paladino
Keyword(s):  
Coastal Waters ◽  
Satellite Telemetry ◽  
State Space Model ◽  
Chelonia Mydas ◽  
Equatorial Guinea ◽  
Bioko Island ◽  
Green Turtles ◽  
Satellite Transmitters ◽  
Anthropogenic Threats ◽  
Polluted Waters

AbstractThis study is the first to use satellite telemetry to track post-nesting movements of endangered green turtles (Chelonia mydas) in the Gulf of Guinea. Satellite transmitters were attached in 2018 to six Atlantic green turtles nesting on Bioko Island, Equatorial Guinea, to track their post-nesting movements and locate their foraging grounds. Track lengths of 20-198 days were analyzed, for a total of 536 movement days for the six turtles. Migratory pathways and foraging grounds were identified by applying a switching state space model to locational data, which provides daily position estimates to identify shifts between migrating and foraging behavior. Turtles exhibited a combination of coastal and oceanic migrations pathways that ranged from 957 km to 1,131 km. Of the six turtles, five completed their migration and maintained residency at the same foraging ground near the coastal waters of Accra, Ghana until transmission was lost. These five resident turtles inhabit heavily fished and polluted waters and are vulnerable to a variety of anthropogenic threats. The identification of these foraging grounds highlights the importance of these coastal waters for the protection of the endangered Atlantic green turtle.

scholarly journals Movements and Inferred Foraging by Bowhead Whales in the Canadian Beaufort Sea during August and September, 2006–12

ARCTIC ◽  
2017 ◽  
Vol 70 (2) ◽  
pp. 161 ◽  
Author(s):  
Lois A. Harwood ◽  
Lori T. Quakenbush ◽  
Robert J. Small ◽  
J. Craig George ◽  
James Pokiak ◽  
...  
Keyword(s):  
Canadian Arctic ◽  
Late Summer ◽  
Beaufort Sea ◽  
Bowhead Whale ◽  
Shallow Waters ◽  
Bowhead Whales ◽  
Location Data ◽  
State Switching ◽  
Photographic Evidence ◽  
Density Contour

Each spring, most bowhead whales of the Bering-Chukchi-Beaufort (BCB) population migrate to the southeast Beaufort Sea and summer in Canadian waters. In August and September, they form aggregations, which are known to occur mainly in the shallow, shelf waters when oceanographic conditions promote concentration of their zooplankton prey. The movements of individual bowheads while they occupy these late summer habitats are less well known; our knowledge is based on photographic evidence and limited tagging studies conducted from 1982 to 2000. In this study, 85% (17) of the 20 satellite-tagged whales that could have spent some time in the Canadian portion of the Beaufort Sea during late summer 2006 to 2012 spent all or part of August and September there. We analyzed location data for 16 whales, using a two-state switching correlated random walk (CRW) behavioural model, and classified locations in the Canadian waters as associated with lingering behaviour (inferred foraging) or directed travel. We found that these whales spent the greatest proportion of their time lingering (59%), followed by traveling (22%), and transitioning between lingering and traveling (19%). Using only lingering locations for these tagged whales in all study years pooled, we calculated kernel densities and defined five areas within the 75% density contour as aggregation areas. Together, the five aggregation areas we defined comprised 25 341 km2, 14.1% of the total area used by these tagged whales in Canadian waters during August and September of the deployment years. Three aggregation areas were located in shallow waters of the Beaufort Sea Shelf and were used almost exclusively by immature tagged whales in our sample. Two other aggregation areas were observed, one in Darnley Bay and one in Viscount Melville Sound in the Canadian Arctic Archipelago. Each of these was used by one mature whale. Tagged whales were observed to use one or two aggregation areas in a single season, and rarely more. The proportion of lingering time spent in each aggregation area was highly variable among individuals. The largest aggregation area (10 877 km2), located over the Beaufort Shelf north of the Tuktoyaktuk Peninsula (5 – 52 m depth), was used by 13 of the 16 tagged whales, almost exclusively by the immature whales, including three of four that were tracked in two consecutive summers. The Beaufort Shelf overall (and possibly the Tuktoyaktuk Shelf, including the Outer Shelf, in particular) was especially important for immature bowhead whales, while mature whales used habitats beyond the Beaufort Shelf during late summer. Findings may be important to inform both decisions on management and mitigative actions relating to bowhead whale use of the Beaufort Shelf and studies that aim to improve our understanding of the prey base of BCB bowhead whales in the Canadian Beaufort Sea region.

scholarly journals Sustained disruption of narwhal habitat use and behavior in the presence of Arctic killer whales

2017 ◽  
Vol 114 (10) ◽  
pp. 2628-2633 ◽  
Author(s):  
Greg A. Breed ◽  
Cory J. D. Matthews ◽  
Marianne Marcoux ◽  
Jeff W. Higdon ◽  
Bernard LeBlanc ◽  
...  
Keyword(s):  
Satellite Telemetry ◽  
State Space Model ◽  
Movement Behavior ◽  
Marine Animal ◽  
Tracking Data ◽  
Killer Whales ◽  
Marine Animals ◽  
General Importance ◽  
And Behavior ◽  
Admiralty Inlet

Although predators influence behavior of prey, analyses of electronic tracking data in marine environments rarely consider how predators affect the behavior of tracked animals. We collected an unprecedented dataset by synchronously tracking predator (killer whales,N= 1; representing a family group) and prey (narwhal,N= 7) via satellite telemetry in Admiralty Inlet, a large fjord in the Eastern Canadian Arctic. Analyzing the movement data with a switching-state space model and a series of mixed effects models, we show that the presence of killer whales strongly alters the behavior and distribution of narwhal. When killer whales were present (within about 100 km), narwhal moved closer to shore, where they were presumably less vulnerable. Under predation threat, narwhal movement patterns were more likely to be transiting, whereas in the absence of threat, more likely resident. Effects extended beyond discrete predatory events and persisted steadily for 10 d, the duration that killer whales remained in Admiralty Inlet. Our findings have two key consequences. First, given current reductions in sea ice and increases in Arctic killer whale sightings, killer whales have the potential to reshape Arctic marine mammal distributions and behavior. Second and of more general importance, predators have the potential to strongly affect movement behavior of tracked marine animals. Understanding predator effects may be as or more important than relating movement behavior to resource distribution or bottom-up drivers traditionally included in analyses of marine animal tracking data.

Spatial components of bowhead whale (Balaena mysticetus) distribution in the Alaskan Beaufort Sea

2000 ◽  
Vol 57 (11) ◽  
pp. 2193-2200 ◽  
Author(s):  
R S Schick ◽  
D L Urban
Keyword(s):  
Spatial Analysis ◽  
Beaufort Sea ◽  
Bowhead Whale ◽  
Oil Exploration ◽  
Balaena Mysticetus ◽  
Bowhead Whales ◽  
Drilling Rig ◽  
Mantel Tests ◽  
Marine Realm ◽  
Drilling Rigs

Bowhead whales (Balaena mysticetus) on their fall migration are exposed to oil exploration activities in the Alaskan Beaufort Sea. While previous research into the effect of industrial noise on whale behavior and distribution has noted significant responses, this research has often proceeded from a parametric statistical framework. To account for the presence of spatially autocorrelated and intercorrelated data, we propose a suite of spatial analysis techniques to assess the distribution of bowhead whales relative to oil exploration activities. Using random resampling techniques and Mantel tests, we analyzed the distribution of bowhead whales around active drilling rigs in 1993. Results from the resampling tests indicated that whales were distributed farther from the drilling rig than they would be under a random scenario. Results from the Mantel tests indicated that in 1993, the spatial pattern of bowhead whale distribution was highly correlated with distance from the drilling rig, indicating that the presence of the drilling rig resulted in a significant temporary loss in available habitat. These techniques offer a new perspective on spatial analysis in the marine realm.

scholarly journals Seasonal differences in migration strategies of Red Kites (Milvus milvus) wintering in Spain

2021 ◽  
Author(s):  
Jorge García-Macía ◽  
Javier Vidal-Mateo ◽  
Javier De La Puente ◽  
Ana Bermejo ◽  
Rainer Raab ◽  
...  
Keyword(s):  
Spring Migration ◽  
Great Variability ◽  
Autumn Migration ◽  
Seasonal Differences ◽  
North Eastern ◽  
Wintering Areas ◽  
Satellite Transmitters ◽  
Migration Strategies ◽  
Migratory Movements ◽  
Milvus Milvus

AbstractRed Kite shows a great variability in its migration strategies: most individuals in north-eastern Europe are migrants, but there is also a growing number of sedentary individuals. Here, we tagged 49 Red Kites wintering in Spain with GPS/satellite transmitters between 2013 and 2020 to study the autumn and spring migration between the breeding or summering areas in Central Europe and the wintering quarters in Spain. In first place, differences between immatures and adults were found for spring migration. Adults began the spring migration towards the northeast in February–March while the immature individuals began to migrate significantly later and showing a wider date range (February-June). Adults also takes significantly less days to arrive at their destinations (12 ± 5 days) and cover more distance per day (134.2 ± 37.1 km/day) than immatures (19 ± 11 days and 98.9 ± 21.2 km/day). In second place, we also found differences between spring and autumn migration (excluding immatures). Spring migrations were clearly faster and with less stopovers days than autumn migrations. Autumn migration began between mid-October and late November and two different behaviours were observed: most birds made a quick migration direct to the wintering areas with only some days of stopovers, but others prolonged the migration with long stops along the route. These results highlight a great variation in the migratory movements of Red Kite, not only according to age but also between individuals and seasons.

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