scholarly journals Uncertain status of the northern bottlenose whale Hyperoodon ampullatus: population fragmentation, legacy of whaling and current threats

2012 ◽  
Vol 19 (1) ◽  
pp. 47-61 ◽  
Author(s):  
H Whitehead ◽  
SK Hooker
2017 ◽  
Vol 43 (5) ◽  
pp. 474-478 ◽  
Author(s):  
Rita Ferreira ◽  
Filipe Alves ◽  
Claudia Gomes ◽  
Daniel Jardim ◽  
Judith Kok ◽  
...  

Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  

Most species now have fragmented distributions, often with adverse genetic consequences. The genetic impacts of population fragmentation depend critically upon gene flow among fragments and their effective sizes. Fragmentation with cessation of gene flow is highly harmful in the long term, leading to greater inbreeding, increased loss of genetic diversity, decreased likelihood of evolutionary adaptation and elevated extinction risk, when compared to a single population of the same total size. The consequences of fragmentation with limited gene flow typically lie between those for a large population with random mating and isolated population fragments with no gene flow.


1975 ◽  
Vol 32 (7) ◽  
pp. 1019-1040 ◽  
Author(s):  
Edward Mitchell ◽  
V. Michael Kozicki

A 615-cm male northern bottlenose whale (Hyperoodon ampullatus) stranded in Cobequid Bay, Bay of Fundy, in early October 1969. The skull, mandible, tympano-periotics, and teeth are described and illustrated. Five growth layers in the lower teeth place the animal below a growth curve based on samples from the Labrador Sea taken in May and June. A summary of nine other North American occurrences of 12 individuals, mainly south of Sable Island, indicates a winter migration to waters offshore of Massachusetts and Rhode Island.


2021 ◽  
Author(s):  
Arolyn Conwill ◽  
Anne C Kuan ◽  
Ravalika Damerla ◽  
Alexandra J Poret ◽  
Jacob S Baker ◽  
...  

What enables strains of the same species to coexist in a microbiome? Here, we investigate if host anatomy can explain strain co-residence of Cutibacterium acnes, the most abundant species on human skin. We reconstruct on-person evolution and migration using 947 C. acnes colony genomes acquired from 16 subjects, including from individual skin pores, and find that pores maintain diversity by limiting competition. Although strains with substantial fitness differences coexist within centimeter-scale regions, each pore is dominated by a single strain. Moreover, colonies from a pore typically have identical genomes. An absence of adaptive signatures suggests a genotype-independent source of low within-pore diversity. We therefore propose that pore anatomy imposes random single-cell bottlenecks during migration into pores and subsequently blocks new migrants; the resulting population fragmentation reduces competition and promotes coexistence. Our findings imply that therapeutic interventions involving pore-dwelling species should focus on removing resident populations over optimizing probiotic fitness.


Author(s):  
M.B. Santos ◽  
G.J. Pierce ◽  
C. Smeenk ◽  
M.J. Addink ◽  
C.C. Kinze ◽  
...  

This paper presents information on the stomach contents of four northern bottlenose whales Hyperoodon ampullatus (Odontoceti: Ziphiidae) from the north-east Atlantic, an area for which there are few recent data on the feeding ecology of this species. Two of these whales were relatively recent strandings, a female stranded in August 1993 at Hargen (the Netherlands) and a male stranded in February 1997 on the island of Tåsinge (Denmark). Stomach content samples were also examined from a juvenile male stranded in November 1885 at Dunbar (Scotland) and a female stranded in August 1956 on the island of Texel (the Netherlands).  Food remains from the four samples consisted almost entirely of cephalopod beaks. Some fish remains were also found in the stomach of the Hargen and Tåsinge whales, and the latter also had crustacean remains in the stomach. The cephalopod prey consisted mainly of oceanic cephalopods: Gonatus sp. (probably G. fabricii, Cephalopoda: Teuthoidea), Taoniuspavo and Histioteuthis sp. for the Dunbar whale; Gonatus and Teuthowenia megalops for the Texel whale; Gonatus for the Hargen whale and Gonatus, T. megalops and Taonius pavo for the Tåsinge whale. Other prey species found in the Tåsinge specimen included the squid Histioteuthis reversa, H. arcturi, and the octopods Vampiroteuthis infernalis and Vitreledonella richardi. Based on the size of the lower beaks, the squid eaten included juvenile and mature individuals of the most important species (Gonatus and Teuthowenia megalops). The fish remains consisted of vertebrae of Gadidae and fish eye lenses (Hargen whale) and two Trisopterus otoliths (Tåsinge whale).  The results from this study are in agreement with those of previous authors in that cephalopods in general, and G. fabricii in particular, are the main prey of the northern bottlenose whale and other toothed whales in northern latitudes.


Oryx ◽  
2002 ◽  
Vol 36 (1) ◽  
pp. 56-65 ◽  
Author(s):  
Mike Maunder ◽  
Wayne Page ◽  
John Mauremootoo ◽  
Richard Payendee ◽  
Yousoof Mungroo ◽  
...  

Abstract The conservation status of the five genera and 11 species of palm endemic to the Mascarene Islands (Mauritius, La Réunion and Rodriques) are reviewed. All species are threatened with extinction; nine taxa are classified as Critically Endangered and four as Endangered on the 2000 IUCN Red List. Two taxa survive as single wild specimens (Hyophorbe amaricaulis and Dictyosperma album var. conjugatum); an additional seven taxa have wild populations of 100 or fewer. Although the historical phase of large-scale forest clearance has passed, the remaining palm populations in the Mascarenes are under threat from the effects of population fragmentation, invasive plants and animals, and high levels of seed predation that prevent natural regeneration. The advantages of in situ management for the recovery of these palm populations are discussed. Without a long-term conservation programme, utilising both in situ and ex situ management, extinction of wild populations will occur.


2005 ◽  
Vol 62 (11) ◽  
pp. 2573-2585 ◽  
Author(s):  
Hal Whitehead ◽  
Tonya Wimmer

A population of northern bottlenose whales (Hyperoodon ampullatus) inhabits the waters along the edge of the Scotian Shelf. The most important habitat of this population is the Gully, a large submarine canyon, where animals were photographically identified between 1988 and 2003. Open mark–recapture models, including mixture models that allow for heterogeneity in identifiability and (or) mortality among individuals, were fitted to identification-history data. Models without heterogeneity in identifiability had poor fit to the data and underestimated population size. The population is estimated to contain about 163 animals (95% confidence interval 119–214), with no statistically significant temporal trend. About 12% of the population has a high probability of being identified within the Gully in any year. Many of them are mature males. The remainder is less likely to be identified in the Gully during any year, spend generally shorter periods in the Gully even in years when they are found, and are more likely to be female. This and other work indicate a poorly mixed population inhabiting the canyons and other deeper waters off the Scotian Shelf. Non parametric bootstrap methods were used to validate the estimation procedure and to estimate the efficiency of future fieldwork scenarios.


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