Long-term survival despite low genetic diversity in the critically endangered Madagascar fish-eagle

Author(s):  
JEFF A. JOHNSON ◽  
RUTH E. TINGAY ◽  
MELANIE CULVER ◽  
FRANK HAILER ◽  
MICHÈLE L. CLARKE ◽  
...  
2021 ◽  
Vol 43 ◽  
pp. 167-191
Author(s):  
Krisztina A. Kelemen ◽  
Felicita Urzi ◽  
Elena Buzan ◽  
Győző F. Horváth ◽  
Filip Tulis ◽  
...  

The distribution of the endangered glacial relict subspecies, the Pannonian root vole Alexandromys oeconomus mehelyi Éhik, 1928, is restricted to scattered localities in south-western Slovakia, which belong to the north-eastern zone of its range. Human-induced changes and fragmentation of the landscape have led to the gradual loss of suitable habitats and threaten its long-term survival. The study area in the Danubian Lowland is characterised by small habitat fragments and temporal fluctuations of the habitat area. Root voles were sampled at nine sites to study the level of genetic variability and structure of local subpopulations by scoring 13 microsatellite loci in 69 individuals. Genetic differentiation varied amongst local populations and we did not find a significant isolation-by-distance pattern. Bayesian clustering analysis suggested that dispersal effectively prevents marked genetic subdivision between studied habitat fragments. Significant pairwise differentiation between some subpopulations, however, may be the result of putatively suppressed gene flow. Low genetic diversity in the recent populations probably reflects the isolated location of the study area in the agricultural landscape, suggesting that long-term survival may not be assured. In order to maintain genetic diversity, it is essential to preserve (or even restore) habitats and ensure the possibility of gene flow; habitat protection is, therefore, recommended. Continuous assessment is necessary for effective conservation management and to predict the long-term survival chances of the Pannonian root vole in the study area.


Oryx ◽  
2021 ◽  
pp. 1-7
Author(s):  
Tommaso Savini ◽  
Nay Myo Shwe ◽  
Niti Sukumal

Abstract From 1999 onwards, level, lowland forests (altitude < 150 m, slopes < 10°) in the Tanintharyi Region of southern Myanmar have been cleared on a large scale and replaced by oil palm plantations. This has resulted in a drastic decline in suitable habitat for several species, including Gurney's pitta Hydrornis gurneyi (Passeriformes, Pittidae). The habitat for this species has decreased by > 80%, leading to its categorization as Critically Endangered on the IUCN Red List in 2019. As threats in the region have continued, we updated information on the status of the species’ habitat in January 2020, and examined forest loss in the three strongholds where the species still persists in the wild. Since the previous estimate in 2017, suitable habitat in these locations has decreased by 8% (from 656 to 603 km2), with > 10% of the remaining area now in fragments of < 1 km2, which are unsuitable for the mid- to long-term survival of the species. Forest degradation and edge effects from increased fragmentation have led to further loss of suitable habitat in these strongholds. Projections indicate that unless conservation action is taken, all suitable habitat will disappear by 2080. The main threat to the long-term survival of Gurney's pitta is the lack of legal protection of primary lowland forests, resulting in uncontrolled clearance for small- and large-scale agriculture and industrial development. We provide recommendations to reduce the rate of loss of the remaining suitable habitat for the species.


Oryx ◽  
2012 ◽  
Vol 46 (2) ◽  
pp. 236-239 ◽  
Author(s):  
Hugh L. Wright ◽  
Nigel J. Collar ◽  
Iain R. Lake ◽  
Net Norin ◽  
Rours Vann ◽  
...  

AbstractThe population size of the Critically Endangered white-shouldered ibis Pseudibis davisoni has always been poorly known. The first-ever census across Cambodia in 2009–2010 using simultaneous counts at multiple roost sites found substantially more birds than previously estimated, with a minimum of 523 individuals. The census allowed us to make a revised global population estimate of 731–856 individuals, increasing hope for the species' long-term survival. However, the largest subpopulations are imminently threatened by development and c. 75% of the birds counted in Cambodia were outside protected areas.


2018 ◽  
Vol 285 (1875) ◽  
pp. 20172589 ◽  
Author(s):  
Beata Ujvari ◽  
Marcel Klaassen ◽  
Nynke Raven ◽  
Tracey Russell ◽  
Marion Vittecoq ◽  
...  

Genetic diversity is essential for adaptive capacities, providing organisms with the potential of successfully responding to intrinsic and extrinsic challenges. Although a clear reciprocal link between genetic diversity and resistance to parasites and pathogens has been established across taxa, the impact of loss of genetic diversity by inbreeding on the emergence and progression of non-communicable diseases, such as cancer, has been overlooked. Here we provide an overview of such associations and show that low genetic diversity and inbreeding associate with an increased risk of cancer in both humans and animals. Cancer being a multifaceted disease, loss of genetic diversity can directly (via accumulation of oncogenic homozygous mutations) and indirectly (via increased susceptibility to oncogenic pathogens) impact abnormal cell emergence and escape of immune surveillance. The observed link between reduced genetic diversity and cancer in wildlife may further imperil the long-term survival of numerous endangered species, highlighting the need to consider the impact of cancer in conservation biology. Finally, the somewhat incongruent data originating from human studies suggest that the association between genetic diversity and cancer development is multifactorial and may be tumour specific. Further studies are therefore crucial in order to elucidate the underpinnings of the interactions between genetic diversity, inbreeding and cancer.


Lankesteriana ◽  
2015 ◽  
Vol 7 (1-2) ◽  
Author(s):  
Pilar Orega-Larrocea ◽  
Mónica Rangel-Villafranco

Preservation of genetic diversity of orchids for con- servation and restoration purposes is now a feasible practice after the ecological studies of seed bank dynamics made by several investigators (Batty et al. 2001, Whigham et al. 2006). However, few studies have demonstrated the reliability of reintroduction of several species into their natural habitat and less, managing symbiotic fungus (Ramsay and Dixon 2003, Zettler et al. 2003).


2000 ◽  
Vol 111 (1) ◽  
pp. 363-370 ◽  
Author(s):  
Katsuto Takenaka ◽  
Mine Harada ◽  
Tomoaki Fujisaki ◽  
Koji Nagafuji ◽  
Shinichi Mizuno ◽  
...  

2001 ◽  
Vol 120 (5) ◽  
pp. A747-A748
Author(s):  
S DRESNER ◽  
A IMMMANUEL ◽  
P LAMB ◽  
S GRIFFIN

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