scholarly journals Larger body size leads to greater female beluga whale ovarian reproductive activity at the southern periphery of their range

2021 ◽  
Author(s):  
Steven Ferguson ◽  
David Yurkowski ◽  
Justine Hudson ◽  
Tera Edkins ◽  
Cornelia Willing ◽  
...  
Keyword(s):  
Body Size ◽  
Body Length ◽  
Reproductive Activity ◽  
Food Competition ◽  
Beluga Whale ◽  
Delphinapterus Leucas ◽  
Hudson Bay ◽  
Beluga Whales ◽  
Future Challenges ◽  
Variation Explained

Identification of phenotypic characteristics in reproductively successful individuals provides important insights into the evolutionary processes that cause range shifts due to environmental change. Female beluga whales (Delphinapterus leucas) from the Baffin Bay region (BB) of the Canadian Arctic in the core area of the species’ geographic range have larger body size than their conspecifics at the southern range periphery in Hudson Bay (HB). We investigated the mechanism for this north and south divergence as it relates to ovarian reproductive activity (ORA = total corpora) that combines morphometric data with ovarian corpora counted from female reproductive tracts. Based on the previous finding of reproductive senescence in older HB females, but not for BB whales, we compared ORA patterns of the two populations with age and body length. Female beluga whale ORA increased more quickly with age (63% partial variation explained) in BB than in HB (41%). In contrast, body length in HB female beluga whales accounted for considerably more of the total variation (12 vs 1%) in ORA compared to BB whales. We speculate that female HB beluga whale ORA was more strongly linked with body length due to higher population density resulting in food competition that favors the energetic advantages of larger body size during seasonal food limitations. Understanding the evolutionary mechanism of how ORA varies across a species’ range will assist conservation efforts in anticipating and mitigating future challenges associated with a warming planet.

scholarly journals Larger body size leads to greater female beluga whale reproductive activity at the southern periphery of their range

2021 ◽  
Author(s):  
Steven Ferguson ◽  
David Yurkowski ◽  
Justine Hudson ◽  
Tera Edkins ◽  
Cornelia Willing ◽  
...  
Keyword(s):  
Body Size ◽  
Body Length ◽  
Reproductive Activity ◽  
Food Competition ◽  
Beluga Whale ◽  
Delphinapterus Leucas ◽  
Hudson Bay ◽  
Beluga Whales ◽  
Future Challenges ◽  
Variation Explained

Identification of phenotypic characteristics in reproductively successful individuals provides important insights into the evolutionary processes that cause range shifts due to environmental change. Female beluga whales (Delphinapterus leucas) from the Baffin Bay region (BB) of the Canadian Arctic in the core area of the species’ geographic range have larger body size than their conspecifics at the southern range periphery in Hudson Bay (HB). We investigated the mechanism for this north and south divergence as it relates to reproductive activity (RA = total corpora) that combines morphometric data with ovarian corpora counted from female reproductive tracts. Based on the previous finding of reproductive senescence in older HB females, but not for BB whales, we compared RA patterns the of the two populations’ with age and body length. Female beluga whale RA increased more quickly with age (63% partial variation explained) in BB than in HB (41%). In contrast, body length in HB female beluga whale accounted for considerably more of the total variation (12 vs 1%) in RA compared to BB whales. We speculate that female HB beluga whale RA was more strongly linked with body length due to higher population density resulting in food competition that favors the energetic advantages of larger body size during seasonal food limitations. Understanding the evolutionary mechanism of how RA, and potentially fitness, varies across a species’ range will assist conservation efforts in anticipating and mitigating future challenges associated with a warming planet.

scholarly journals Larger body size leads to greater female beluga fitness at the southern periphery of their range

2020 ◽  
Author(s):  
Steven Ferguson ◽  
David Yurkowski ◽  
Justine Hudson ◽  
Tera Edkins ◽  
Cornelia Willing ◽  
...  
Keyword(s):  
Body Size ◽  
Body Length ◽  
High Arctic ◽  
Delphinapterus Leucas ◽  
Causal Mechanism ◽  
Hudson Bay ◽  
Peripheral Populations ◽  
Beluga Whales ◽  
Future Challenges ◽  
Variation Explained

Identifying phenotypic characteristics of evolutionarily fit individuals provides important insight into the evolutionary processes that cause range shifts with climate warming. Female beluga whales (Delphinapterus leucas) from the Canadian high Arctic (BB) residing in the core region of the species’ geographic range are 14% larger than their conspecifics at the southern periphery in Hudson Bay (HB). We investigated the causal mechanism for this north (core)-south (periphery) difference as it relates to fitness by combining morphometric data with ovarian corpora counted in female reproductive tracts. We found evidence for reproductive senescence in older HB females from the southern peripheral population but not for BB whales. Female beluga whale fitness in the more-northern BB increased faster with age (48% partial variation explained) versus a more gradual slope (25%) in HB. In contrast, body length in HB female beluga accounted for five times more of the total variation in fitness compared to BB whales. We speculate that female HB beluga fitness was more strongly linked with body length due to higher density, as larger body size provides survival advantages during seasonal food limitations. Understanding the evolutionary mechanism of how fitness changes will assist conservation efforts in anticipating and mitigating future challenges to peripheral populations.

scholarly journals Reproductive Parameters for Female Beluga Whales (Delphinapterus leucas) of Baffin Bay and Hudson Bay, Canada

ARCTIC ◽  
2020 ◽  
Vol 73 (4) ◽  
pp. 405-420
Author(s):  
Steven H. Ferguson ◽  
Cornelia Willing ◽  
Trish C. Kelley ◽  
David A. Boguski ◽  
David J. Yurkowski ◽  
...  
Keyword(s):  
Sexual Maturity ◽  
Growth Patterns ◽  
Beluga Whale ◽  
The Arctic ◽  
Delphinapterus Leucas ◽  
Hudson Bay ◽  
Reproductive Parameters ◽  
Baffin Bay ◽  
Beluga Whales ◽  
Reproductive Patterns

Monitoring marine mammal populations and their habitats is crucial for assessing population status and defining realistic management and conservation goals. Environmental and anthropogenic changes in the Arctic have prompted the pursuit for improved understanding of female beluga whale (Delphinapterus leucas) spatial and temporal reproductive patterns. There are relatively few estimates for female reproductive parameters of beluga whale populations across the Arctic, and those few that are available are outdated. Here we summarize female reproductive data from samples collected through Inuit subsistence hunts of three eastern Canadian Arctic beluga populations: High Arctic/Baffin Bay (HA), Western Hudson Bay (HB), and Cumberland Sound (CS) from 1989 to 2014. We grouped the CS and HA populations into a Baffin Bay region (BB) population based on similar body growth patterns and genetic similarity. Asymptotic body length of BB beluga whales (370.9 cm) was greater than HB whales (354.4 cm) as established from Gompertz growth curves fitted for whales ranging in age from 1 – 89 y. We did not detect a significant difference in average number of pseudocervices (8.6) between regions. Differences in average age of sexual maturity (ASM) and length at sexual maturity (LSM) were identified, with evidence of BB females maturing earlier than females from HB (probability method BB = 9.9 y versus HB = 11.0 and logistic method ASM50% HB = 9.99 and BB unresolved). BB females were also longer than HB females at maturing age (logistic LSM50%: BB = 314.5 cm vs HB = 290.3). Total corpora counts were strongly correlated with age, although the number of corpora (≥ 10 mm) suggests reproductive senescence between 40 and 50 y. Improved understanding of female reproductive patterns and knowledge of changes in the spatial and temporal timing of reproductive processes are fundamental for effective conservation and sustainable management of beluga whale populations.

scholarly journals Alaska Beluga Whale Committee—a unique model of co-management

2021 ◽  
Vol 40 ◽  
Author(s):  
Kathryn J. Frost ◽  
Tom Gray ◽  
Willie Goodwin, Sr. ◽  
Roswell Schaeffer ◽  
Robert Suydam
Keyword(s):  
Local Governments ◽  
Cost Effective ◽  
Aerial Survey ◽  
Beluga Whale ◽  
Delphinapterus Leucas ◽  
Funding Agency ◽  
Federal State ◽  
Bristol Bay ◽  
Subsistence Hunting ◽  
Beluga Whales

The Alaska Beluga Whale Committe (ABWC) was formed in 1988 to conserve beluga whales (Delphinapterus leucas) and manage beluga subsistence hunting in western and northern Alaska in cooperation with the National Marine Fisheries Service (NMFS). When the ABWC was formed, there was no consistently funded research or management programme for belugas in Alaska, and co-management was a new concept. The ABWC brought together representatives from beluga hunting communities; federal, state, tribal and local governments; and beluga researchers to develop and implement a programme to manage belugas. With funding from NMFS and others, the ABWC has collected data necessary for informed management decisions including the following: harvest data; aerial surveys of belugas in Bristol Bay and the eastern Bering and Chukchi seas; beluga tracking studies, including training hunters to attach transmitters; a pioneering genetics study of beluga stock identity that has facilitated collection of >2000 beluga skin samples; and a genetics-based mark–recapture study to estimate beluga abundance in Bristol Bay and validate aerial survey estimates. The ABWC is currently engaged in regional management planning in Kotzebue Sound and the eastern Bering Sea. It produces results that are scientifically valid, locally accepted and cost-effective and is an example of what can be achieved when Native hunters, scientists and managing agencies respect and listen to one another and work together. However, the current NMFS co-management funding process has fundamentally altered the relationship between NMFS and ABWC, with NMFS now acting more like a funding agency than a partner.

scholarly journals Genetic profiling links changing sea-ice to shifting beluga whale migration patterns

2016 ◽  
Vol 12 (11) ◽  
pp. 20160404 ◽  
Author(s):  
Greg O'Corry-Crowe ◽  
Andrew R. Mahoney ◽  
Robert Suydam ◽  
Lori Quakenbush ◽  
Alex Whiting ◽  
...  
Keyword(s):  
Sea Ice ◽  
Beluga Whale ◽  
Ocean Dynamics ◽  
Delphinapterus Leucas ◽  
Ecosystem Structure ◽  
Genetic Profiling ◽  
Beluga Whales ◽  
Resource Dispersion ◽  
Ice Conditions ◽  
And Shifts

There is increasing concern over how Arctic fauna will adapt to climate related changes in sea-ice. We used long-term sighting and genetic data on beluga whales ( Delphinapterus leucas ) in conjunction with multi-decadal patterns of sea-ice in the Pacific Arctic to investigate the influence of sea-ice on spring migration and summer residency patterns. Substantial variations in sea-ice conditions were detected across seasons, years and sub-regions, revealing ice–ocean dynamics more complex than Arctic-wide trends suggest. This variation contrasted with a highly consistent pattern of migration and residency by several populations, indicating that belugas can accommodate widely varying sea-ice conditions to perpetuate philopatry to coastal migration destinations. However, a number of anomalous migration and residency events were detected and coincided with anomalous ice years, and in one case with an increase in killer whale ( Orcinus orca ) sightings and reported predation on beluga whales. The behavioural shifts were likely driven by changing sea-ice and associated changes in resource dispersion and predation risk. Continued reductions in sea-ice may result in increased predation at key aggregation areas and shifts in beluga whale behaviour with implications for population viability, ecosystem structure and the subsistence cultures that rely on them.

Whale milk. I. Fin whale (Balaenoptera physalus) and beluga whale (Delphinapterus leucas) milk: gross composition and fatty acid constitution

1969 ◽  
Vol 47 (1) ◽  
pp. 95-97 ◽  
Author(s):  
B. H. Lauer ◽  
B. E. Baker
Keyword(s):  
Fatty Acid ◽  
North Atlantic ◽  
Beluga Whale ◽  
Delphinapterus Leucas ◽  
Hudson Bay ◽  
Balaenoptera Physalus ◽  
Fin Whale ◽  
The North ◽  
The North Atlantic ◽  
Beluga Whale Delphinapterus Leucas

Milk was obtained from a fin whale which was killed in the North Atlantic and from a beluga whale which was killed in Hudson Bay. The gross composition and fatty acid constitution of the milks were determined.

scholarly journals Inuit Knowledge of beluga whale (Delphinapterus leucas) foraging ecology in Nunavik (Arctic Quebec), Canada

2016 ◽  
Vol 94 (10) ◽  
pp. 713-726 ◽  
Author(s):  
K. Breton-Honeyman ◽  
M.O. Hammill ◽  
C.M. Furgal ◽  
B. Hickie
Keyword(s):  
Diet Composition ◽  
Foraging Ecology ◽  
Arctic Region ◽  
Beluga Whale ◽  
The Arctic ◽  
Delphinapterus Leucas ◽  
Hudson Bay ◽  
Productive Area ◽  
Inuit Knowledge ◽  
Beluga Whale Delphinapterus Leucas

The beluga whale (Delphinapterus leucas (Pallas, 1776)) is expected to be influenced by changes in the environment. In Nunavik, the Arctic region of Quebec, Nunavimmiut (Inuit of Nunavik) have depended on beluga for centuries, developing an extensive understanding of the species and its ecology. Forty semidirective interviews were conducted with Inuit hunters and Elders from four Nunavik communities, who had a range of 28–47 years of beluga hunting experience. Interviews followed an ethnocartographic format and were analyzed using a mixed methods approach. Hunters most commonly reported prey species from the sculpin (Cottidae), cod (Gadidae), salmon (Salmonidae), and crustacean families; regional variations in prey and in foraging habitat were found. Hunters identified significant changes in body condition (i.e., blubber thickness), which were associated with observations about the seasonality of feeding. The timing of fat accumulation in the late fall and winter coupled with the understanding that Hudson Bay is not known as a productive area suggest alternate hypotheses to feeding for the seasonal movements exhibited by these whales. Inuit Knowledge of beluga foraging ecology presented here provides information on diet composition and seasonality of energy intake of the beluga and can be an important component of monitoring diet composition for this species into the future. An Inuttitut version of the abstract is available ( Appendix A ).

Sign in / Sign up

Export Citation Format

Share Document