Natural and potentially disturbed behavior of bowhead whales

Würsig, Bernd; Koski, William R.

doi:10.1016/b978-0-12-818969-6.00023-6

Cited by 3 publications

(5 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Eight of nine males in this study had T peaks preceding putative summer δ 15 N peaks by approximately three months, suggesting that breeding in this bowhead whale population occurs during late winter to spring, consistent with observations of increased social activity among bowhead whales from March through May ( Tervo et al. 2009 , 2011 ; Würsig and Koski 2021 ). Satellite telemetry data show that the majority of this bowhead whale population (East Canada-West Greenland population, EC-WG) is located in Hudson Strait and off southeastern Baffin Island at this time ( Ferguson et al.…”

Section: Discussionsupporting

confidence: 87%

“…( Frasier et al. 2007 ; MacLeod 2010 ; Würsig and Koski 2021 ). These traits suggest sperm competition, which in mammals typically entails dramatic seasonal T peaks that elevate coincident with courtship behavior, insemination, and fertilization ( Dixson and Anderson 2004 ; Frasier et al.…”

Section: Discussionmentioning

confidence: 99%

“…1984 ; Tarpley et al. 2021 ; Würsig and Koski 2021 ). Thus, we assume that T peaks are coincident with seasonal mating and fertilization.…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Male Bowhead Whale Reproductive Histories Inferred from Baleen Testosterone and Stable Isotopes

Hunt

Buck

Ferguson

et al. 2022

Integrative Organismal Biology

View full text Add to dashboard Cite

Synopsis Male mammals of seasonally reproducing species typically have annual testosterone (T) cycles, with T usually peaking during the breeding season, but occurrence of such cycles in male mysticete whales has been difficult to confirm. Baleen, a keratinized filter-feeding apparatus of mysticetes, incorporates hormones as it grows, such that a single baleen plate can record years of endocrine history with sufficient temporal resolution to discern seasonal patterns. We analyzed patterns of T every 2 cm across the full length of baleen plates from nine male bowhead whales (Balaena mysticetus) to investigate occurrence and regularity of T cycles and potential inferences about timing of breeding season, sexual maturation, and reproductive senescence. Baleen specimens ranged from 181–330 cm in length, representing an estimated 11 years (smallest whale) to 22 years (largest whale) of continuous baleen growth, as indicated by annual cycles in stable isotopes. All baleen specimens contained regularly spaced areas of high T content (T peaks) confirmed by time series analysis to be cyclic, with periods matching annual stable isotope cycles of the same individuals. In 8 of the 9 whales, T peaks preceded putative summer isotope peaks by a mean of 2.8 months, suggesting a mating season in late winter / early spring. The only exception to this pattern was the smallest and youngest male, which had T peaks synchronous with isotope peaks. This smallest, youngest whale also did not have T peaks in the first half of the plate, suggesting initiation of T cycling during the period of baleen growth. Linear mixed effect models suggest that whale age influences T concentrations, with the two largest and oldest males exhibiting a dramatic decline in T peak concentration across the period of baleen growth. Overall, these patterns are consistent with onset of sexual maturity in younger males and possible reproductive senescence in older males. We conclude that adult male bowheads undergo annual T cycles, and that analyses of T in baleen may enable investigation of reproductive seasonality, timing of the breeding season, and life history of male whales.

show abstract

Section: Discussionsupporting

confidence: 87%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Male Bowhead Whale Reproductive Histories Inferred from Baleen Testosterone and Stable Isotopes

Hunt

Buck

Ferguson

et al. 2022

Integrative Organismal Biology

View full text Add to dashboard Cite

show abstract

“…Consistent with their heavy reliance on sound for communication and navigation, bowheads have proven to be extremely sensitive to underwater anthropogenic noise (Würsig and Koski, 2021;Blackwell and Thode, 2021). In particular, the response of bowheads to airgun noise from marine seismic surveys has been studied intensively since the 1980s, soon after offshore industrial development began off northern Alaska, in the Canadian Beaufort Sea, and in the Lancaster Sound region (Richardson et al, 1995).…”

Section: Noisementioning

confidence: 99%

Bowhead whales and whaling in the central and eastern Canadian Arctic, 1970-2021

Reeves

Lee²

2022

JCRM

View full text Add to dashboard Cite

The history of bowhead whaling and hunt management in the eastern and central Canadian Arctic is reviewed. Subsistence hunting of bowhead whales by Inuit resumed in the 1990s under co-management arrangements that were part of land-claims settlement agreements. Removals by whaling in both Canada and Greenland have been accounted for in IWC Scientific Committee assessments of the Eastern Canada–West Greenland (EC-WG) stock, but Canada, having withdrawn from IWC membership in 1982, has no legal obligation to consider IWC management advice. From 1994-2021 the total reported catch of bowheads in the central and eastern Canadian Arctic was 39 (not including struck-and-lost whales or whales that died from incidental entanglement in fishing gear). Sixteen different communities, most of which had a long history of bowhead whaling prior to the arrival of commercial whalers, took at least one bowhead over that 27-year period. More than half of the recent catches have been by the communities of Igloolik, Sanijarak, Naujaat and Coral Harbour, all in the Foxe Basin–Repulse Bay–northern Hudson Bay region where at least occasional hunting of bowheads by local people had persisted until well into the 1970s. Greenland’s reported landed catches totaled from 2009-2015, with no successful hunts reported since 2015. Well over a third of the whales landed by both countries combined have been mature females, the most valuable class in terms of potential for population increase. Several factors in addition to hunting and entanglement in fishing gear are likely affecting EC-WG bowheads, including increased exposure to killer whale predation (linked to the massive reduction in sea ice) and other changes in ecological conditions driven primarily by climate change (e.g. more industrial activity, more vessel traffic, more noise). Recent analyses suggest the EC-WG stock of bowheads has grown considerably since the end of commercial whaling, with best estimates of current abundance in the range of 6000-7000 individuals. Even though the population appears capable of sustaining present levels of removal and disturbance, it is important for monitoring efforts to continue in both Canada and Greenland, with regular Indigenous participation. Local observations and traditional knowledge can be valuable sources of information on animal health, behaviour and phenology.

show abstract

“…As such, seemingly-isolated whales may still be benefiting from collective navigation via long-distance communication across a widely dispersed group [5, 13]. Substance to such conjectures can be found in the sequences of calls made by humpbacks, tens of kilometres apart, while traversing migration routes [14] or the apparent exchange of calls between bowhead whales as they navigate around ice [15].…”

Section: Introductionmentioning

confidence: 99%

Avoidance, confusion or solitude? Modelling how noise pollution affects whale migration

Johnston,

Painter

2023

Preprint

View full text Add to dashboard Cite

Many baleen whales are renowned for their acoustic communication. Under pristine conditions, this communication can plausibly occur across hundreds of kilometres. Frequent vocalisations may allow a dispersed migrating group to maintain contact, and therefore benefit from improved navigation via the “wis-dom of the crowd.” Human activities have considerably inflated ocean noise levels. Here we develop a data-driven mathematical model to investigate how ambient noise levels may inhibit whale migration. Mathematical models allow us to simul-taneously simulate collective whale migration behaviour, auditory cue detection, and noise propagation. Rising ambient noise levels are hypothesised to influence navigation through three mechanisms: (i) diminished communication space; (ii) reduced ability to hear external sound cues and; (iii) triggering noise avoidance behaviour. Comparing pristine and current soundscapes, we observe navigation impairment that ranges from mild (increased journey time) to extreme (failed navigation). Notably, the three mechanisms induce qualitatively different impacts on migration behaviour. We demonstrate the model’s potential predictive power, exploring the extent to which migration may be altered under future shipping and construction scenarios.

show abstract

Natural and potentially disturbed behavior of bowhead whales

Cited by 3 publications

References 46 publications

Male Bowhead Whale Reproductive Histories Inferred from Baleen Testosterone and Stable Isotopes

Male Bowhead Whale Reproductive Histories Inferred from Baleen Testosterone and Stable Isotopes

Bowhead whales and whaling in the central and eastern Canadian Arctic, 1970-2021

Avoidance, confusion or solitude? Modelling how noise pollution affects whale migration

Contact Info

Product

Resources

About