Contribution to unravel variability in bowhead whale songs and better understand its ecological significance

AbstractSince the first studies on bowhead whale singing behaviour, song variations have been consistently reported. However, there has been little discussion regarding variability in bowhead whale singing display and its ecological significance. Unlike the better studied humpback whales, bowhead whales do not appear to share songs at population level, but several studies have reported song sharing within clusters of animals. Over the winter season 2013–2014, in an unstudied wintering ground off Northeast Greenland, 13 song groups sharing similar hierarchical structure and units were identified. Unit types were assessed through multidimensional maps, showing well separated clusters corresponding to manually labelled units, and revealing the presence of unit subtypes. Units presented contrasting levels of variability over their acoustic parameters, suggesting that bowhead whales keep consistency in some units while using a continuum in values of frequency, duration and modulation parameters for other unit types. Those findings emphasise the need to account for variability in song analysis to better understand the behavioural ecology of this endangered species. Additionally, shifting from song toward units or phrase-based analysis, as it has been suggested for humpback whales, offers the opportunity to identify and track similarities in songs over temporal and geographical scales relevant to population monitoring.

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Do researchers impact their study populations? Assessing the effect of field procedures in a long term population monitoring of sea kraits

Amphibia-Reptilia ◽

10.1163/15685381-00002839 ◽

2012 ◽

Vol 33 (3-4) ◽

pp. 365-372 ◽

Cited By ~ 11

Author(s):

Thomas Fauvel ◽

François Brischoux ◽

Marine Jeanne Briand ◽

Xavier Bonnet

Keyword(s):

Body Condition ◽

New Caledonia ◽

Stress Hormones ◽

Population Level ◽

Population Monitoring ◽

Long Term Effects ◽

Negative Effects ◽

Short Term ◽

Head Morphology

Long term population monitoring is essential to ecological studies; however, field procedures may disturb individuals. Assessing this topic is important in worldwide declining taxa such as reptiles. Previous studies focussed on animal welfare issues and examined short-term effects (e.g. increase of stress hormones due to handling). Long-term effects with possible consequences at the population level remain poorly investigated. In the present study, we evaluated the effects of widely used field procedures (e.g. handling, marking, forced regurgitation) both on short-term (hormonal stress response) and on long-term (changes in body condition, survival) scales in two intensively monitored populations of sea kraits (Laticauda spp.) in New Caledonia. Focusing on the most intensively monitored sites, from 2002 to 2012, we gathered approximately 11 200 captures/recaptures on 4500 individuals. Each snake was individually marked (scale clipping + branding) and subjected to various measurements (e.g. body size, head morphology, palpation). In addition, a subsample of more than 500 snakes was forced to regurgitate their prey for dietary analyses. Handling caused a significant stress hormonal response, however we found no detrimental long-term effect on body condition. Forced regurgitation did not cause any significant effect on both body condition one year later and survival. These results suggest that the strong short-term stress provoked by field procedures did not translate into negative effects on the population. Although similar analyses are required to test the validity of our conclusions in other species, our results suggest distinguishing welfare and population issues to evaluate the potential impact of population surveys.

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Paradoxical population resilience of a keystone predator to a toxic invasive species

Wildlife Research ◽

10.1071/wr19150 ◽

2020 ◽

Vol 47 (3) ◽

pp. 260

Author(s):

J. Sean Doody ◽

David Rhind ◽

Simon Clulow

Keyword(s):

Population Level ◽

Population Monitoring ◽

Cane Toad ◽

Keystone Predator ◽

Individual Effects ◽

Before And After ◽

Animal Communities ◽

Better Than ◽

Population Resilience

Abstract ContextThe invasive cane toad (Rhinella marina) has decimated populations of a keystone predator, the yellow-spotted monitor (Varanus panoptes), causing trophic cascades in Australian animal communities. Paradoxically, some V. panoptes populations coexist with toads. Demonstrating patterns in heterogeneous population-level impacts could reveal mechanisms that mediate individual effects, and provide managers with the ability to predict future impacts and assist in population recovery. AimsThe aim of the present study was to search for spatial patterns of population resilience of V. panoptes to invasive cane toads. MethodsPublished literature, unpublished data, reports and anecdotal information from trained herpetologists were used to test the emerging hypothesis that resilient predator populations are mainly coastal, whereas non-resilient populations are mostly inland. Key resultsPost-toad invasion data from 23 V. panoptes populations supported the idea that toad impacts on V. panoptes were heterogeneous; roughly half the populations could be designated as resilient (n=13) and half as non-resilient (n=10). Resilient populations had longer times since toad invasion than did non-resilient populations (39 versus 9 years respectively), supporting the idea that some recovery can occur. Non-resilient populations were exclusively inland (n=10), whereas resilient populations were split between inland (n=5) and coastal (n=8) populations. Resilient inland populations, however, were mainly confined to areas in which decades had passed since toad invasion. ConclusionsThe findings suggest that coastal V. panoptes populations fare much better than inland populations when it comes to surviving invading cane toads. ImplicationsUnambiguous recovery of monitor populations remains undemonstrated and will require long-term population monitoring before and after toad invasion.

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Mitogenomics and the genetic differentiation of contemporary Balaena mysticetus (Cetacea) from Svalbard

Zoological Journal of the Linnean Society ◽

10.1093/zoolinnean/zlaa082 ◽

2020 ◽

Author(s):

Lutz Bachmann ◽

Andrea A Cabrera ◽

Mads Peter Heide-Jørgensen ◽

Olga V Shpak ◽

Christian Lydersen ◽

...

Keyword(s):

Genetic Differentiation ◽

High Throughput Sequencing ◽

Demographic History ◽

Bowhead Whale ◽

Recent Common Ancestor ◽

Mitochondrial Genomes ◽

Balaena Mysticetus ◽

Bowhead Whales ◽

Most Recent Common Ancestor ◽

Loop Region

Abstract Full mitochondrial genomes were assembled for 12 recently sampled animals from the Svalbard bowhead whale (Balaena mysticetus) stock via high-throughput sequencing data, facilitating analysis of the demographic history of the population for the first time. The Svalbard population has retained noticeable amounts of mitochondrial genome diversity despite extreme historical harvest levels. Haplotype and nucleotide diversities were similar to those estimated earlier for other bowhead whale populations. The reconstructed demographic history was in accordance with a boom–bust scenario, combining a slight Pleistocene population growth 25 000–35 000 years ago and a Holocene decline. Employing a mutation rate of 3.418 × 10–8 substitutions per site per year, the time to the most recent common ancestor for the mitochondrial genomes of the contemporary Svalbard bowhead whales was estimated to be 68 782 (54 353–83 216) years before the present. Based on 370 bp fragments of the D-loop region, significant genetic differentiation was detected between all extant bowhead whale populations across the circumpolar Arctic. Thus, the Svalbard bowhead whales can be regarded as a population with its own genetic legacy.

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Age estimation for young bowhead whales (Balaena mysticetus) using annual baleen growth increments

Canadian Journal of Zoology ◽

10.1139/z08-028 ◽

2008 ◽

Vol 86 (6) ◽

pp. 525-538 ◽

Cited By ~ 44

Author(s):

S. C. Lubetkin ◽

J. E. Zeh ◽

C. Rosa ◽

J. C. George

Keyword(s):

Growth Parameters ◽

Age Determination ◽

Population Level ◽

Exponential Model ◽

Growth Increment ◽

Balaena Mysticetus ◽

Nonlinear Mixed Effects Model ◽

Bowhead Whales ◽

Growth Increments ◽

Age Estimates

We compiled age estimates and baleen plate δ13C data from 86 bowhead whales ( Balaena mysticetus L., 1758). We used previous whale age estimates based on aspartic acid racemization (AAR) and corpora counts to extend the use of δ13C data for age determination from cycle counting to a modified exponential model using annual baleen growth increments. Our approach used the growth increment data from individual whales in a nonlinear mixed effects model to assess both population-level and whale-specific growth parameters. Although age estimates from baleen-based models become less precise as the whales age, and baleen growth and length near steady state, the growth increment model shows promise in estimating ages of bowhead whales 10–13.5 m long with baleen lengths <250 cm, where other techniques are less precise or the data are scarce. Ages estimated using the growth increment data from such whales ranged from 6.4 to 19.8 years.

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Comment on “Genetic analysis of 16th-century whale bones prompts a revision of the impact of Basque whaling on right and bowhead whales in the western North Atlantic”

Canadian Journal of Zoology ◽

10.1139/z06-085 ◽

2006 ◽

Vol 84 (7) ◽

pp. 1059-1065 ◽

Cited By ~ 3

Author(s):

Aldemaro Romero ◽

Shelly Kannada

Keyword(s):

Genetic Analysis ◽

North Atlantic ◽

Small Sample ◽

Bowhead Whale ◽

16Th Century ◽

Bowhead Whales ◽

The North ◽

The North Atlantic ◽

Red Bay ◽

The Impact

Rastogi et al. presented their genetic analysis of 16th-century whale bones found on a Basque whaling ship excavated from Red Bay, Labrador Peninsula, Canada. Based on the results from a very small sample, these authors concluded that whaling populations were already depleted before the onset of whaling. This is in direct contradiction to historical data. They also implied that the Basques were the only Europeans whaling in the North Atlantic before the onset of Yankee whaling and that there was a belief that Basque whalers historically killed equal numbers of right and bowhead whales. Here we present data based on historical and archaeological records generated by several authors using different methodologies, which clearly show that (i) Basques were not the only whalers that impacted cetacean populations in the North Atlantic; (ii) the number of whales killed by different peoples for approximately two centuries indicates that both right and bowhead whale population levels were much higher than typically assumed; and (iii) for many years there have been records published indicating that the Basques and others killed more bowhead whales than right whales, at least in the western North Atlantic.

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Distribution and Abundance of the Eastern Canada – West Greenland Bowhead Whale Population Based on the 2013 High Arctic Cetacean Survey

NAMMCO Scientific Publications ◽

10.7557/3.5315 ◽

2020 ◽

Vol 11 ◽

Author(s):

Thomas Doniol-Valcroze ◽

Jean-François Gosselin ◽

Daniel G. Pike ◽

Jack W. Lawson ◽

Natalie C. Asselin ◽

...

Keyword(s):

High Arctic ◽

Diving Behaviour ◽

Bowhead Whale ◽

Survey Area ◽

Eastern Canada ◽

West Greenland ◽

Bowhead Whales ◽

Abundance Estimate ◽

Track Line ◽

Canada West

The hunting of bowhead whales (Balaena mysticetus) is an integral part of Inuit culture. An up-to-date abundance estimate of the entire Eastern Canada – West Greenland (EC-WG) bowhead population is necessary to support sustainable management of this harvest. The High Arctic Cetacean Survey (HACS) was conducted in August 2013, primarily to update abundance estimates for known stocks of Baffin Bay narwhal (Monodon monoceros). As the ranges of narwhal and bowhead largely overlap, the survey area was expanded to cover the summer range of bowhead whales. Bowhead whale abundance was estimated using 3 aircraft to cover the large survey area within a short time frame. Distance sampling methods were used to estimate detection probability away from the track line. Double platform with mark-recapture methods were used to correct for the proportion of whales missed by visual observers on the track line (perception bias). Abundance in Isabella Bay, an area known for high bowhead density, was estimated using density surface modelling to account for its complex shape and uneven coverage. Estimates were corrected for availability bias (whales that were not available for detection because they were submerged when the aircraft passed overhead) using a recent analysis of satellite-linked time depth recorders transmitting information on the diving behaviour of bowhead whales in the study area in August of the same survey year. The fully corrected abundance estimate for the EC-WG bowhead whale population was 6,446 (95% CI: 3,838–10,827). Possible sources of uncertainty include incomplete coverage and the diving behaviour of bowhead whales. These results confirm earlier indications that the EC-WG stock is continuing to recover from past overexploitation.

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Bowhead whales, and not right whales, were the primary target of 16th- to 17th-century Basque Whalers in the Western North Atlantic

ARCTIC ◽

10.14430/arctic7 ◽

2009 ◽

Vol 61 (1) ◽

pp. 61 ◽

Cited By ~ 25

Author(s):

B.A. McLeod ◽

M.W. Brown ◽

M.J. Moore ◽

W. Stevens ◽

S.H. Barkham ◽

...

Keyword(s):

North Atlantic ◽

17Th Century ◽

Bowhead Whale ◽

North Atlantic Right Whale ◽

Bowhead Whales ◽

Right Whale ◽

The North ◽

Mitochondrial Cytochrome B ◽

Comprehensive Search ◽

The North Atlantic

During the 16th and 17th centuries, Basque whalers travelled annually to the Strait of Belle Isle and Gulf of St. Lawrence to hunt whales. The hunting that occurred during this period is of primary significance for the North Atlantic right whale, Eubalaena glacialis (Müller, 1776), because it has been interpreted as the largest human-induced reduction of the western North Atlantic population, with ~12250–21 000 whales killed. It has been frequently reported that the Basques targeted two species in this region: the North Atlantic right whale and the bowhead whale, Balaena mysticetus L., 1758. To evaluate this hypothesis and the relative impact of this period of whaling on both species, we collected samples from 364 whale bones during a comprehensive search of Basque whaling ports from the 16th to the 17th century in the Strait of Belle Isle and Gulf of St. Lawrence. Bones were found and sampled at 10 of the 20 sites investigated. DNA was extracted from a subset (n = 218) of these samples. Analysis of the mitochondrial cytochrome b region identified five whale species. The identification of only a single right whale bone and 203 bowhead whale bones from at least 72 individuals indicates that the bowhead whale was likely the principal target of the hunt. These results imply that this whaling had a much greater impact (in terms of numbers of whales removed) on the bowhead whale population than on the western North Atlantic right whale population.

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Killer whale presence drives bowhead whale selection for sea ice in Arctic seascapes of fear

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1911761117 ◽

2020 ◽

Vol 117 (12) ◽

pp. 6590-6598 ◽

Cited By ~ 9

Author(s):

Cory J. D. Matthews ◽

Greg A. Breed ◽

Bernard LeBlanc ◽

Steven H. Ferguson

Keyword(s):

Habitat Use ◽

Sea Ice ◽

Terrestrial Ecosystem ◽

Arctic Sea Ice ◽

Bowhead Whale ◽

Apex Predators ◽

Killer Whales ◽

Ice Dynamics ◽

Bowhead Whales ◽

And Behavior

The effects of predator intimidation on habitat use and behavior of prey species are rarely quantified for large marine vertebrates over ecologically relevant scales. Using state space movement models followed by a series of step selection functions, we analyzed movement data of concurrently tracked prey, bowhead whales (Balaena mysticetus;n= 7), and predator, killer whales (Orcinus orca; n= 3), in a large (63,000 km2), partially ice-covered gulf in the Canadian Arctic. Our analysis revealed pronounced predator-mediated shifts in prey habitat use and behavior over much larger spatiotemporal scales than previously documented in any marine or terrestrial ecosystem. The striking shift from use of open water (predator-free) to dense sea ice and shorelines (predators present) was exhibited gulf-wide by all tracked bowheads during the entire 3-wk period killer whales were present, constituting a nonconsumptive effect (NCE) with unknown energetic or fitness costs. Sea ice is considered quintessential habitat for bowhead whales, and ice-covered areas have frequently been interpreted as preferred bowhead foraging habitat in analyses that have not assessed predator effects. Given the NCEs of apex predators demonstrated here, however, unbiased assessment of habitat use and distribution of bowhead whales and many marine species may not be possible without explicitly incorporating spatiotemporal distribution of predation risk. The apparent use of sea ice as a predator refuge also has implications for how bowhead whales, and likely other ice-associated Arctic marine mammals, will cope with changes in Arctic sea ice dynamics as historically ice-covered areas become increasingly ice-free during summer.

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Increasing abundance of bowhead whales in West Greenland

Biology Letters ◽

10.1098/rsbl.2007.0310 ◽

2007 ◽

Vol 3 (5) ◽

pp. 577-580 ◽

Cited By ~ 39

Author(s):

Mads Peter Heide-Jørgensen ◽

Kristin Laidre ◽

David Borchers ◽

Filipa Samarra ◽

Harry Stern

Keyword(s):

Survey Design ◽

Large Population ◽

Aerial Survey ◽

Bowhead Whale ◽

West Greenland ◽

Threshold Size ◽

Bowhead Whales ◽

Abundance Estimate ◽

Surface Time ◽

Severe Reduction

In April 2006, a dedicated survey of bowhead whales ( Balaena mysticetus ) was conducted on the former whaling ground in West Greenland to determine the current wintering population abundance. This effort included a double platform aerial survey design, satellite tracking of the movements of nine whales, and estimation of high-resolution surface time from 14 whales instrumented with time–depth recorders. Bowhead whales were estimated to spend an average of 24% (cv=0.03) of the time at or above 2 m depth, the maximum depth at which they can be seen on the trackline. This resulted in a fully corrected abundance estimate of 1229 (95% CI: 495–2939) bowhead whales when the availability factor was applied and sightings missed by observers were corrected. This surprisingly large population estimate is puzzling given that the change in abundance cannot be explained by a recent or rapid growth in population size. One possible explanation is that the population, which demonstrates high age and sex segregation, has recently attained a certain threshold size elsewhere, and a higher abundance of mature females appears on the winter and spring feeding ground in West Greenland. This in combination with the latest severe reduction in sea ice facilitating access to coastal areas might explain the surprising increase in bowhead whale abundance in West Greenland.

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

Canadian Journal of Zoology ◽

10.1139/z00-045 ◽

2000 ◽

Vol 78 (7) ◽

pp. 1168-1181 ◽

Cited By ~ 26

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.

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