scholarly journals Long-term Declines in the Size of Northern Fulmar (Fulmarus glacialis) Colonies on Eastern Baffin Island, Canada

ARCTIC ◽  
2020 ◽  
Vol 73 (2) ◽  
pp. 187-194 ◽  
Author(s):  
Mark L. Mallory ◽  
Cody J. Dey ◽  
Jessie McIntyre ◽  
Isabeau Pratte ◽  
Carolyn L. Mallory ◽  
...  
Keyword(s):  
Population Size ◽  
Baffin Island ◽  
Northern Fulmar ◽  
Arctic Canada ◽  
Fulmarus Glacialis ◽  
Winter Food ◽  
Potential Population ◽  
Fisheries Bycatch ◽  
Annual Decline

We censused three colonies of Northern Fulmars (Fulmarus glacialis) along eastern Baffin Island, Canada, that were estimated to support 155 000 breeding pairs in 1973, but had not been adequately counted since then. The colonies were surveyed in July and August 2018 using photographs taken from a helicopter or a drone. The combined estimated colony sizes were 36 500 pairs, much smaller than historical estimates. Although the 1973 estimates were coarse, this difference represents an apparent 3+% annual decline in numbers at each colony over approximately four decades or more than 87% over three generations (66 years). Several factors may be contributing to these declines, including changes in winter food supplies and the susceptibility of fulmars to fisheries bycatch. We recommend efforts to survey the remaining major fulmar colonies in Arctic Canada to assess the overall population size and trends, and allow for further analyses of potential population drivers.

Update on the Boundaries of the Curly Birch Range

2020 ◽  
pp. 9-21
Author(s):  
L.V. Vetchinnikova ◽  
◽  
A.F. Titov ◽  
◽  
Keyword(s):  
Population Size ◽  
Natural Populations ◽  
Forest Tree ◽  
Published Data ◽  
Population Approach ◽  
Key Factors ◽  
History Of ◽  
Individual Trees ◽  
Karelian Birch

The article reports on the application of the best known principles for mapping natural populations of curly (Karelian) birch Betula pendula Roth var. carelica (Mercklin) Hämet-Ahti – one of the most appealing representatives of the forest tree flora. Relying on the synthesis and analysis of the published data amassed over nearly 100 years and the data from own full-scale studies done in the past few decades almost throughout the area where curly birch has grown naturally, it is concluded that its range outlined in the middle of the 20th century and since then hardly revised is outdated. The key factors and reasons necessitating its revision are specified. Herewith it is suggested that the range is delineated using the population approach, and the key element will be the critical population size below which the population is no longer viable in the long term. This approach implies that the boundaries of the taxon range depend on the boundaries of local populations (rather than the locations of individual trees or small clumps of trees), the size of which should not be lower than the critical value, which is supposed to be around 100–500 trees for curly birch. A schematic map of the curly birch range delineated using this approach is provided. We specially address the problem of determining the minimum population size to secure genetic diversity maintenance. The advantages of the population approach to delineating the distribution range of curly birch with regard to its biological features are highlighted. The authors argue that it enables a more accurate delineation of the range; shows the natural evolutionary history of the taxon (although it is not yet officially recognized as a species) and its range; can be relatively easily updated (e.g. depending on the scope of reintroduction); should be taken into account when working on the strategy of conservation and other actions designed to maintain and regenerate this unique representative of the forest tree flora.

scholarly journals Can we reestablish a self-sustaining population? A case study on reintroduced Crested Ibis with population viability analysis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yashuai Zhang ◽  
Fang Wang ◽  
Zhenxia Cui ◽  
Min Li ◽  
Xia Li ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Population Size ◽  
Carrying Capacity ◽  
Wild Population ◽  
Population Viability Analysis ◽  
Population Viability ◽  
Viability Analysis ◽  
Crested Ibis ◽  
Reintroduced Population

Abstract Background One of the most challenging tasks in wildlife conservation and management is clarifying which and how external and intrinsic factors influence wildlife demography and long-term viability. The wild population of the Crested Ibis (Nipponia nippon) has recovered to approximately 4400, and several reintroduction programs have been carried out in China, Japan and Korea. Population viability analysis on this endangered species has been limited to the wild population, showing that the long-term population growth is restricted by the carrying capacity and inbreeding. However, gaps in knowledge of the viability of the reintroduced population and its drivers in the release environment impede the identification of the most effective population-level priorities for aiding in species recovery. Methods The field monitoring data were collected from a reintroduced Crested Ibis population in Ningshan, China from 2007 to 2018. An individual-based VORTEX model (Version 10.3.5.0) was used to predict the future viability of the reintroduced population by incorporating adaptive patterns of ibis movement in relation to catastrophe frequency, mortality and sex ratio. Results The reintroduced population in Ningshan County is unlikely to go extinct in the next 50 years. The population size was estimated to be 367, and the population genetic diversity was estimated to be 0.97. Sensitivity analysis showed that population size and extinction probability were dependent on the carrying capacity and sex ratio. The carrying capacity is the main factor accounting for the population size and genetic diversity, while the sex ratio is the primary factor responsible for the population growth trend. Conclusions A viable population of the Crested Ibis can be established according to population viability analysis. Based on our results, conservation management should prioritize a balanced sex ratio, high-quality habitat and low mortality.

scholarly journals Agglomeration economies, congestion diseconomies, and fertility dynamics in a two-region economy

2021 ◽  
Author(s):  
Madoka Muroishi ◽  
Akira Yakita
Keyword(s):  
Population Size ◽  
Stability Condition ◽  
Fertility Rate ◽  
Model Parameters ◽  
Initial Population ◽  
Interregional Migration ◽  
Stable Path ◽  
Regional Population ◽  
Initial Population Size

AbstractUsing a small, open, two-region economy model populated by two-period-lived overlapping generations, we analyze long-term agglomeration economy and congestion diseconomy effects of young worker concentration on migration and the overall fertility rate. When the migration-stability condition is satisfied, the distribution of young workers between regions is obtainable in each period for a predetermined population size. Results show that migration stability does not guarantee dynamic stability of the economy. The stationary population size stability depends on the model parameters and the initial population size. On a stable trajectory converging to the stationary equilibrium, the overall fertility rate might change non-monotonically with the population size of the economy because of interregional migration. In each period, interregional migration mitigates regional population changes caused by fertility differences on the stable path. Results show that the inter-regional migration-stability condition does not guarantee stability of the population dynamics of the economy.

scholarly journals The source of topography across the Cumberland Peninsula, Baffin Island, Arctic Canada: differential exhumation of a North Atlantic rift flank

2019 ◽  
Vol 176 (6) ◽  
pp. 1093-1106 ◽  
Author(s):  
Scott Jess ◽  
Randell Stephenson ◽  
Søren B. Nielsen ◽  
Roderick Brown
Keyword(s):  
North Atlantic ◽  
Baffin Island ◽  
Arctic Canada

scholarly journals Long-term inference of population size and habitat use in a socially dynamic population of wild western lowland gorillas

2019 ◽  
Vol 20 (6) ◽  
pp. 1303-1314 ◽  
Author(s):  
Laura Hagemann ◽  
Mimi Arandjelovic ◽  
Martha M. Robbins ◽  
Tobias Deschner ◽  
Matthew Lewis ◽  
...  
Keyword(s):  
Habitat Use ◽  
Population Size ◽  
Western Lowland Gorillas ◽  
Dynamic Population ◽  
Lowland Gorillas

Mechanism and Ecological Significance of Sperm Storage in the Northern Fulmar with Reference to Its Occurrence in Other Birds

The Auk ◽  
1983 ◽  
Vol 100 (3) ◽  
pp. 593-600 ◽  
Author(s):  
Scott A. Hatch
Keyword(s):  
Sexual Behavior ◽  
Reproductive System ◽  
Sperm Storage ◽  
Egg Laying ◽  
Ecological Significance ◽  
Northern Fulmar ◽  
Male And Female ◽  
Fulmarus Glacialis ◽  
Oceanodroma Leucorhoa ◽  
Horned Puffin

Abstract Sperm-storage glands were found in the uterovaginal (UV) region of the oviduct in Northern Fulmars (Fulmarus glacialis), Horned Puffins (Fratercula corniculata), and Leach's Storm-Petrels (Oceanodroma leucorhoa) collected before or shortly after egg laying. Previously described only in domestic Galliformes, UV sperm-storage glands may prove to be a common feature of the avian reproductive system. There is as yet no compelling explanation of their function in the Horned Puffin. In the Northern Fulmar, and probably in other petrels, however, sperm-storage glands allow the separation of the male and female over pelagic waters for several weeks immediately before egg laying. The likelihood of prolonged viability of sperm in the female reproducitve tract should be considered in interpreting the sexual behavior of other wild birds.

scholarly journals Breeding status influences timing but not duration of moult in the Northern Fulmar Fulmarus glacialis

Ibis ◽  
2019 ◽  
Vol 162 (2) ◽  
pp. 446-459 ◽  
Author(s):  
Antoine Grissot ◽  
Isla M. Graham ◽  
Lucy Quinn ◽  
Vegard S. Bråthen ◽  
Paul M. Thompson
Keyword(s):  
Northern Fulmar ◽  
Fulmarus Glacialis ◽  
Breeding Status
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