scholarly journals Small population size and extremely low levels of genetic diversity in island populations of the platypus,Ornithorhynchus anatinus

2012 ◽  
Vol 2 (4) ◽  
pp. 844-857 ◽  
Author(s):  
Elise Furlan ◽  
J. Stoklosa ◽  
J. Griffiths ◽  
N. Gust ◽  
R. Ellis ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Small Population ◽  
Island Populations ◽  
Small Population Size ◽  
Ornithorhynchus Anatinus ◽  
Low Levels

scholarly journals Conservation biology of threatened Mediterranean chasmophytes: The case of Asperula naufraga endemic to Zakynthos island (Ionian islands, Greece)

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246706 ◽  
Author(s):  
Anna-Thalassini Valli ◽  
Vassiliki Lila Koumandou ◽  
Gregoris Iatrou ◽  
Marios Andreou ◽  
Vasileios Papasotiropoulos ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Extinction Risk ◽  
Conservation Status ◽  
Small Population ◽  
Ex Situ ◽  
Current Conservation ◽  
Ionian Islands ◽  
Small Population Size ◽  
Area Of Occupancy

Asperula naufraga is a rare and threatened obligate chasmophyte, endemic to Zakynthos island (Ionian islands, Greece). In this study, we provide a combined approach (including monitoring of demographic and reproductive parameters and study of genetic diversity) to assess the current conservation status of the species and to estimate its future extinction risk. The five subpopulations of A. naufraga were monitored for five years (2014–2018). Population size markedly fluctuated between 68–130 mature individuals during the monitoring period. The extent of occurrence (EOO) was estimated at 28.7 km2 and the area of occupancy (AOO) was 8 km2. Stage-structure recordings were similar for all subpopulations, characterized by high proportions of adult and senescent individuals, following a common pattern, which has been observed in other cliff-dwelling plants. Preliminary genetic analysis with SSRs markers revealed low heterozygosity within subpopulations and significant departure from H-W equilibrium, which combined with small population size suggest increased threat of genetic diversity loss. Our results indicate that the species should be placed in the Critically Endangered (CR) IUCN threat category, while according to Population Viability Analysis results its extinction risk increases to 47.8% in the next 50 years. The small population size combined with large fluctuations in its size, low recruitment and low genetic diversity, indicate the need of undertaking effective in situ and ex situ conservation measures.

scholarly journals No reduction in genetic diversity of Swiss stone pine (Pinus cembra L.) in Tatra Mountains despite high fragmentation and small population size

2014 ◽  
Vol 15 (6) ◽  
pp. 1433-1445 ◽  
Author(s):  
Artur Dzialuk ◽  
Igor Chybicki ◽  
Roman Gout ◽  
Tomasz Mączka ◽  
Peter Fleischer ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
No Reduction ◽  
Small Population ◽  
Tatra Mountains ◽  
Pinus Cembra ◽  
Stone Pine ◽  
Small Population Size ◽  
Swiss Stone Pine

Evolutionary genetics of small populations

2017 ◽  
Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Evolutionary Genetics ◽  
Small Population ◽  
Small Populations ◽  
Effective Population ◽  
Genetic Management ◽  
Evolutionary Genetic ◽  
Loss Of Genetic Diversity ◽  
Number Of Individuals

Genetic management of fragmented populations involves the application of evolutionary genetic theory and knowledge to alleviate problems due to inbreeding and loss of genetic diversity in small population fragments. Populations evolve through the effects of mutation, natural selection, chance (genetic drift) and gene flow (migration). Large outbreeding, sexually reproducing populations typically contain substantial genetic diversity, while small populations typically contain reduced levels. Genetic impacts of small population size on inbreeding, loss of genetic diversity and population differentiation are determined by the genetically effective population size, which is usually much smaller than the number of individuals.

Eumops floridanus (Chiroptera: Molossidae)

2021 ◽  
Vol 53 (1009) ◽  
pp. 125-133
Author(s):  
Jessica M Vannatta ◽  
Jeffery A Gore ◽  
Verity L Mathis ◽  
Brian D Carver
Keyword(s):  
United States ◽  
Population Size ◽  
The United States ◽  
Small Population ◽  
Species Level ◽  
Small Population Size ◽  
Restricted Distribution ◽  
Dead Trees ◽  
Fish And Wildlife Service

Abstract Eumops floridanus (Allen, 1932) is a molossid commonly called the Florida bonneted bat or the Florida mastiff bat. Eumops floridanus is the largest species of bat in Florida and is one of 16 species in the genus Eumops. With one of the smallest distributions of any bat in the United States, it is endemic to southern peninsular Florida where it roosts in cavities of live and dead trees and man-made structures. Eumops floridanus was formerly classified as a subspecies of E. glaucinus but has been elevated to species level based on morphology. Due primarily to its restricted distribution, small population size, and the continued loss of habitat, E. floridanus is federally listed as “Endangered” (EN) by the United States Fish and Wildlife Service.

scholarly journals Clipperton Atoll as a model to study small marine populations: Endemism and the genomic consequences of small population size

PLoS ONE ◽  
2018 ◽  
Vol 13 (6) ◽  
pp. e0198901 ◽  
Author(s):  
Nicole L. Crane ◽  
Juliette Tariel ◽  
Jennifer E. Caselle ◽  
Alan M. Friedlander ◽  
D. Ross Robertson ◽  
...  
Keyword(s):  
Population Size ◽  
Small Population ◽  
Small Population Size

Small population size limits reproduction in an invasive grass through both demography and genetics

Oecologia ◽  
2012 ◽  
Vol 172 (1) ◽  
pp. 109-117 ◽  
Author(s):  
Jeffrey L. Firestone ◽  
Marie Jasieniuk
Keyword(s):  
Population Size ◽  
Small Population ◽  
Invasive Grass ◽  
Small Population Size ◽  
Size Limits

scholarly journals The abundance of false killer whale, Pseudorca crassidens (Artiodactyla: Delphinidae) in coastal waters of Golfo Dulce and Osa Peninsula, Costa Rica

2020 ◽  
Vol 68 (2) ◽  
Author(s):  
Erika Sánchez Robledo ◽  
Lenin Enrique Oviedo Correa ◽  
David Herra-Miranda ◽  
Juan Diego Pacheco-Polanco ◽  
Sierra Goodman ◽  
...  
Keyword(s):  
Costa Rica ◽  
Population Size ◽  
Killer Whale ◽  
Small Population ◽  
Killer Whales ◽  
Apparent Survival ◽  
Osa Peninsula ◽  
Small Population Size ◽  
False Killer Whale ◽  
Pseudorca Crassidens

Introduction: False killer whale (Pseudorca crassidens) is a tropical and subtropical social species that live in groups with individuals of mixed ages and sex classes. False killer whales have been documented since the late 1990s in Southwestern Costa Rica. Objective: To estimate the abundance of false killer whales in Osa Peninsula waters. Methods: Cetacean surveys off the Osa Peninsula Waters (OPW), Costa Rica, yielded opportunistic encounters with false killer whales in Drake Bay and Caño Island (2001-2015) and observations during formal surveys in Golfo Dulce (2005-2015). Photo-identification data was analyzed using capture-mark-recapture models in the study area, through an open population (POPAN) framework, considering the effect of time on the parameters apparent survival and capture probability, producing an abundance estimate for a superpopulation in the entire study area. Results: False killer whale abundance in OPW is characterized by a small population size of no more than 100 individuals, complemented by a very low probability of encounter and a contrasting high apparent survival. Conclusions: This population estimate should be taken as conservative, however, the small population size of less than 100 individuals should be considered vulnerable, in contrast to the increasing anthropogenic impacts in the coastal seascape. We argue the potential occurrence of population units along the coastal seascape of the Pacific littoral and oceanic island-associated units at Isla del Coco.

scholarly journals Detecting a Literary Future in the Historical Past: The Gibraltar Case

2015 ◽  
Vol 11 (2 (14)) ◽  
pp. 123-134
Author(s):  
John A. Stotesbury
Keyword(s):  
Population Size ◽  
Present Article ◽  
Literary Culture ◽  
Small Population ◽  
Autonomous Community ◽  
Literary Identity ◽  
Small Population Size ◽  
The Past ◽  
British Colonial ◽  
Historical Past

Until the present millennium, very little creative literary writing in either English or Spanish had been published in the British colonial enclave of Gibraltar. Given the small population size of the autonomous community of some 30,000 people, it was considered unlikely that a “national” literary culture could form. In the course of the past decade, a handful of dedicated writers have published a noticeable amount of fiction, all of which is concerned with establishing a recognized Gibraltarian literary identity. The present article, while not arguing for the permanence of a Gibraltarian national literary culture, attempts to trace some of the ways in which a small, unified, geopolitical territory has attempted to tell its own story.

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