Crumbling Island Keystones: Threat Diversity and Intensification on Islands Push Large Island Fruit Bats to the Brink

2021 ◽  
Author(s):  
Tigga Kingston ◽  
F B Vincent Florens ◽  
Christian E Vincenot

Large island fruit bats (LIFB), species of Pteropus, Acerodon, and related genera in the pteropodid subfamily Pteropodinae, are keystone species for island conservation in the Palaeotropics, playing critical roles as agents of dispersal and pollination of native island plant communities. This keystone role is crumbling because LIFB are collectively the most threatened group of bats in the world. Six species (7.4%) have gone extinct in the last 200 years and ~66% of extant species are assessed as threatened by the IUCN. Life history characteristics, long lives, and low reproductive rates, elevate vulnerability and species are commonly subject to multiple threats. Here we review the primary threats to LIFB, namely unsustainable hunting, habitat degradation and loss, urbanisation, climate change, invasive species, and persecution. We highlight how the island context intensifies and accelerates population and species declines. We make specific recommendations in response to the major threats and identify overarching research needs to support conservation action. Specifically, research is needed that addresses: (1) population sizes and trends; (2) life history and social ecology; (3) dietary, roosting and movement ecology; (4) human attitudes and behaviors towards LIFB; (5) island-specific threats to LIFB; (6) distributions, populations and ecology of non-Pteropus species. Although there is great complexity of threats and contexts, five key conservation actions emerge that have the collective potential to secure LIFB populations throughout their ranges: (1) protect and restore native habitats; (2) improve attitudes and behaviours towards LIFB; (3) strengthen protective legislation and enforcement; (4) captive breeding of species at immediate risk of extinction; (5) build and network research and conservation capacity.Key words: flying fox, monkey-faced bat, island conservation, keystone species, Pteropus, Acerodon, hunting, habitat loss, climate change.

Oryx ◽  
2019 ◽  
Vol 54 (1) ◽  
pp. 52-61
Author(s):  
Shaun W. Molloy ◽  
Allan H. Burbidge ◽  
Sarah Comer ◽  
Robert A. Davis

AbstractTranslocation of species to areas of former habitat after threats have been mitigated is a common conservation action. However, the long-term success of reintroduction relies on identification of currently available habitat and areas that will remain, or become, habitat in the future. Commonly, a short-term view is taken, focusing on obvious and assumed threats such as predators and habitat degradation. However, in areas subject to significant climate change, challenges include correctly identifying variables that define habitat, and considering probable changes over time. This poses challenges with species such as the western ground parrot Pezoporus flaviventris, which was once relatively common in near-coastal south-western Australia, an area subject to major climate change. This species has declined to one small population, estimated to comprise < 150 individuals. Reasons for the decline include altered fire regimes, introduced predators and habitat clearing. The establishment of new populations is a high priority, but the extent to which a rapidly changing climate has affected, and will continue to affect, this species remains largely conjecture, and understanding probable climate change impacts is essential to the prioritization of potential reintroduction sites. We developed high-resolution species distribution models and used these to investigate climate change impacts on current and historical distributions, and identify locations that will remain, or become, bioclimatically suitable habitat in the future. This information has been given to an expert panel to identify and prioritize areas suitable for site-specific management and/or translocation.


2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Daniel E Winkler ◽  
Michelle Yu-Chan Lin ◽  
José Delgadillo ◽  
Kenneth J Chapin ◽  
Travis E Huxman

We studied how a rare, endemic alpine cushion plant responds to the interactive effects of warming and drought. Overall, we found that both drought and warming negatively influenced the species growth but that existing levels of phenotypic variation may be enough to at least temporarily buffer populations.


Oryx ◽  
2021 ◽  
pp. 1-10
Author(s):  
Riley A. Pollom ◽  
Gina M. Ralph ◽  
Caroline M. Pollock ◽  
Amanda C.J. Vincent

Abstract Few marine taxa have been comprehensively assessed for their conservation status, despite heavy pressures from fishing, habitat degradation and climate change. Here we report on the first global assessment of extinction risk for 300 species of syngnathiform fishes known as of 2017, using the IUCN Red List criteria. This order of bony teleosts is dominated by seahorses, pipefishes and seadragons (family Syngnathidae). It also includes trumpetfishes (Aulostomidae), shrimpfishes (Centriscidae), cornetfishes (Fistulariidae) and ghost pipefishes (Solenostomidae). At least 6% are threatened, but data suggest a mid-point estimate of 7.9% and an upper bound of 38%. Most of the threatened species are seahorses (Hippocampus spp.: 14/42 species, with an additional 17 that are Data Deficient) or freshwater pipefishes of the genus Microphis (2/18 species, with seven additional that are Data Deficient). Two species are Near Threatened. Nearly one-third of syngnathiformes (97 species) are Data Deficient and could potentially be threatened, requiring further field research and evaluation. Most species (61%) were, however, evaluated as Least Concern. Primary threats to syngnathids are (1) overexploitation, primarily by non-selective fisheries, for which most assessments were determined by criterion A (Hippocampus) and/or (2) habitat loss and degradation, for which assessments were determined by criterion B (Microphis and some Hippocampus). Threatened species occurred in most regions but more are found in East and South-east Asia and in South African estuaries. Vital conservation action for syngnathids, including constraining fisheries, particularly non-selective extraction, and habitat protection and rehabilitation, will benefit many other aquatic species.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dennis Rödder ◽  
Thomas Schmitt ◽  
Patrick Gros ◽  
Werner Ulrich ◽  
Jan Christian Habel

AbstractClimate change impacts biodiversity and is driving range shifts of species and populations across the globe. To understand the effects of climate warming on biota, long-term observations of the occurrence of species and detailed knowledge on their ecology and life-history is crucial. Mountain species particularly suffer under climate warming and often respond to environmental changes by altitudinal range shifts. We assessed long-term distribution trends of mountain butterflies across the eastern Alps and calculated species’ specific annual range shifts based on field observations and species distribution models, counterbalancing the potential drawbacks of both approaches. We also compiled details on the ecology, behaviour and life-history, and the climate niche of each species assessed. We found that the highest altitudinal maxima were observed recently in the majority of cases, while the lowest altitudes of observations were recorded before 1980. Mobile and generalist species with a broad ecological amplitude tended to move uphill more than specialist and sedentary species. As main drivers we identified climatic conditions and topographic variables, such as insolation and solar irradiation. This study provides important evidence for responses of high mountain taxa to rapid climate change. Our study underlines the advantage of combining historical surveys and museum collection data with cutting-edge analyses.


2018 ◽  
Vol 25 (2) ◽  
pp. 448-458 ◽  
Author(s):  
Ivan Jarić ◽  
Robert J. Lennox ◽  
Gregor Kalinkat ◽  
Gorčin Cvijanović ◽  
Johannes Radinger

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7333 ◽  
Author(s):  
José Maria Cardoso da Silva ◽  
Alessandro Rapini ◽  
Luis Cláudio F. Barbosa ◽  
Roger R. Torres

In a world where changes in land cover and climate happen faster than ever due to the expansion of human activities, narrowly distributed species are predicted to be the first to go extinct. Studies projecting species extinction in tropical regions consider either habitat loss or climate change as drivers of biodiversity loss but rarely evaluate them together. Here, the contribution of these two factors to the extinction risk of narrowly distributed species (with ranges smaller than 10,000 km2) of seed plants endemic to a fifth-order watershed in Brazil (microendemics) is assessed. We estimated the Regional Climate Change Index (RCCI) of these watersheds (areas with microendemics) and projected three scenarios of land use up to the year 2100 based on the average annual rates of habitat loss in these watersheds from 2000 to 2014. These scenarios correspond to immediate conservation action (scenario 1), long-term conservation action (scenario 2), and no conservation action (scenario 3). In each scenario, areas with microendemics were classified into four classes: (1) areas with low risk, (2) areas threatened by habitat loss, (3) areas threatened by climate change, and (4) areas threatened by climate change and habitat loss. We found 2,354 microendemic species of seed plants in 776 areas that altogether cover 17.5% of Brazil. Almost 70% (1,597) of these species are projected to be under high extinction risk by the end of the century due to habitat loss, climate change, or both, assuming that these areas will not lose habitat in the future due to land use. However, if habitat loss in these areas continues at the prevailing annual rates, the number of threatened species is projected to increase to more than 85% (2,054). The importance of climate change and habitat loss as drivers of species extinction varies across phytogeographic domains, and this variation requires the adoption of retrospective and prospective conservation strategies that are context specific. We suggest that tropical countries, such as Brazil, should integrate biodiversity conservation and climate change policies (both mitigation and adaptation) to achieve win-win social and environmental gains while halting species extinction.


Author(s):  
Roland Cochard

Ever since their evolution, forests have been interacting with the Earth’s climate. Species diversity is particularly high in forests of stable moist tropical climates, but patterns of diversity differ among various taxa. Species richness typically implies high ecosystem resilience to ecosystem disturbances; many species are present to fill in newly created niches and facilitate regeneration. Species loss, on the other hand, often entails environmental degradation and erosion of essential ecosystem services. Until now species extinction rates have been highest on tropical islands which are characterized by a high degree of species endemism but comparatively low species richness (and therefore high vulnerability to invasive species). Deforestation and forest degradation in many countries has lead to forest fragmentation with similar effects on increasingly insularized and vulnerable forest habitat patches. If forest fragments are becoming too small to support important keystone species, further extinctions may occur in cascading ways, and the vegetation structure and composition may eventually collapse. Until now relatively few reported cases of species extinctions can be directly attributed to climate change. However, climate change in combination with habitat destruction, degradation, and fragmentation may lead to new waves of species extinctions in the near future as species are set on the move but are unable to reach cooler refuges due to altered, obstructing landscapes. To mitigate the future risks of extinctions as well as climate change, major efforts should be undertaken to protect intact large areas of forests and restore wildlife corridors. Carbon sequestration may be seen as just one of many other environmental services of forest biodiversity that deserve economic valuation as alternatives to conversion to often unsustainable agricultural uses.


<em>Abstract.</em>—The Washington Department of Fish and Wildlife and Tribal co-managers are using the Ecosystem Diagnosis and Treatment (EDT) model to identify the spatial and temporal habitat limits of salmon populations and predict the effects of proposed habitat restoration projects for ESA-listed Chinook salmon <em>Oncorhynchus tshawytscha </em>in two Puget Sound watersheds. The collaborative, iterative process focused on habitat-based population models for the Dungeness and Dosewallips watersheds. Workshops were held to develop quantitative characteristics of current, historic, hypothetical properly functioning, and future habitat conditions. The model predicted salmon populations in the watersheds for each set of habitat conditions. Recovery targets were based on the predicted populations for historic and hypothetical properly functioning conditions. Future populations were modeled using projected habitat conditions with individual habitat restoration and protection actions already proposed and combinations of these actions. Populations resulting from further habitat degradation were estimated using the effects of projected human population growth on habitat.


2020 ◽  
Vol 117 (30) ◽  
pp. 18119-18126 ◽  
Author(s):  
Line S. Cordes ◽  
Daniel T. Blumstein ◽  
Kenneth B. Armitage ◽  
Paul J. CaraDonna ◽  
Dylan Z. Childs ◽  
...  

Seasonal environmental conditions shape the behavior and life history of virtually all organisms. Climate change is modifying these seasonal environmental conditions, which threatens to disrupt population dynamics. It is conceivable that climatic changes may be beneficial in one season but result in detrimental conditions in another because life-history strategies vary between these time periods. We analyzed the temporal trends in seasonal survival of yellow-bellied marmots (Marmota flaviventer) and explored the environmental drivers using a 40-y dataset from the Colorado Rocky Mountains (USA). Trends in survival revealed divergent seasonal patterns, which were similar across age-classes. Marmot survival declined during winter but generally increased during summer. Interestingly, different environmental factors appeared to drive survival trends across age-classes. Winter survival was largely driven by conditions during the preceding summer and the effect of continued climate change was likely to be mainly negative, whereas the likely outcome of continued climate change on summer survival was generally positive. This study illustrates that seasonal demographic responses need disentangling to accurately forecast the impacts of climate change on animal population dynamics.


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