There is a world somewhere between reality and fiction. Although ignored by many, it is very real and so are those living in it. This forum is about the natural world. Here, wild animals will be heard and respected. The forum offers a glimpse into an unknown world as well as a room with a view on the present and the future. Anyone able to speak on behalf of those living in the emerald forest and the deep blue sea is invited to join.
--- Peter Broekhuijsen ---
Changes in forum policies, read this thread for more detail.

  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Wildfact Library

United Kingdom Sully Offline
Ecology & Rewilding
*****
#31

Comparative Distribution and Habitat Use by Antelope and Mule Deer
 
Abstract

Aerial surveys were used to determine habitat use and distribution of sympatric pronghorn antelope ([i]Antilocapra americana[/i]) and mule deer ([i]Odocoileus hemionus[/i]) populations in eastern Montana from 1982 to 1987. Antelope seasonally occupied only 1–10%, and deer only 9–20%, of the study area. Grassland habitats were used most frequently by antelope; badlands, bunchgrass prairies, and hardwood draws were used most frequently by deer. Some overlap in habitat use was evident but there was little spatial overlap. Maximum overlap in both habitat use and distribution occurred during autumn when antelope moved into deer habitat. There appeared to be little opportunity for interspecific competition during this study based on the high degree of spatial segregation.
1 user Likes Sully's post
Reply

United Kingdom Sully Offline
Ecology & Rewilding
*****
#32

Predation risk constrains herbivores’ adaptive capacity to warming

Abstract

Global warming compels larger endothermic animals to adapt either physiologically or behaviourally to avoid thermal stress, especially in tropical ecosystems. Their adaptive responses may however be compromised by other constraints, such as predation risk or starvation. Using an exceptional camera-trap dataset spanning 32 protected areas across southern Africa, we find that intermediate-sized herbivores (100–550 kg) switch activity to hotter times of the day when exposed to predation by lions. These herbivores face a tight window for foraging activity being exposed to nocturnal predation and to heat during the day, suggesting a trade-off between predation risk and thermoregulation mediated by body size. These findings stress the importance of incorporating trophic interactions into climate change predictions.
1 user Likes Sully's post
Reply

United Kingdom Sully Offline
Ecology & Rewilding
*****
#33

Species better track climate warming in the oceans than on land

Abstract

There is mounting evidence of species redistribution as climate warms. Yet, our knowledge of the coupling between species range shifts and isotherm shifts remains limited. Here, we introduce BioShifts—a global geo-database of 30,534 range shifts. Despite a spatial imbalance towards the most developed regions of the Northern Hemisphere and a taxonomic bias towards the most charismatic animals and plants of the planet, data show that marine species are better at tracking isotherm shifts, and move towards the pole six times faster than terrestrial species. More specifically, we find that marine species closely track shifting isotherms in warm and relatively undisturbed waters (for example, the Central Pacific Basin) or in cold waters subject to high human pressures (for example, the North Sea). On land, human activities impede the capacity of terrestrial species to track isotherm shifts in latitude, with some species shifting in the opposite direction to isotherms. Along elevational gradients, species follow the direction of isotherm shifts but at a pace that is much slower than expected, especially in areas with warm climates. Our results suggest that terrestrial species are lagging behind shifting isotherms more than marine species, which is probably related to the interplay between the wider thermal safety margin of terrestrial versus marine species and the more constrained physical environment for dispersal in terrestrial versus marine habitats.
1 user Likes Sully's post
Reply

United Kingdom Sully Offline
Ecology & Rewilding
*****
#34

Thresholds of mangrove survival under rapid sea level rise

Abstract

The response of mangroves to high rates of relative sea level rise (RSLR) is poorly understood. We explore the limits of mangrove vertical accretion to sustained periods of RSLR in the final stages of deglaciation. The timing of initiation and rate of mangrove vertical accretion were compared with independently modeled rates of RSLR for 78 locations. Mangrove forests expanded between 9800 and 7500 years ago, vertically accreting thick sequences of organic sediments at a rate principally driven by the rate of RSLR, representing an important carbon sink. We found it very likely (>90% probability) that mangroves were unable to initiate sustained accretion when RSLR rates exceeded 6.1 millimeters per year. This threshold is likely to be surpassed on tropical coastlines within 30 years under high-emissions scenarios.
2 users Like Sully's post
Reply

United Kingdom Sully Offline
Ecology & Rewilding
*****
#35

Anthropogenic Disturbance and Population Viability of Woodland Caribou in Ontario

ABSTRACT

One of the most challenging tasks in wildlife conservation and management is to clarify how spatial variation in land cover due to anthropogenic disturbance influences wildlife demography and long‐term viability. To evaluate this, we compared rates of survival and population growth by woodland caribou (Rangifer tarandus caribou ) from 2 study sites in northern Ontario, Canada that differed in the degree of anthropogenic disturbance because of commercial logging and road development, resulting in differences in predation risk due to gray wolves (Canis lupus ). We used an individual‐based model for population viability analysis (PVA) that incorporated adaptive patterns of caribou movement in relation to predation risk and food availability to predict stochastic variation in rates of caribou survival. Field estimates of annual survival rates for adult female caribou in the unlogged (
*This image is copyright of its original author
 0.90) and logged (
*This image is copyright of its original author
 0.76) study sites recorded during 2010–2014 did not differ significantly ( > 0.05) from values predicted by the individual‐based PVA model (unlogged: 
*This image is copyright of its original author
 = 0.87; logged: 
*This image is copyright of its original author
 0.79). Outcomes from the individual‐based PVA model and a simpler stage‐structured matrix model suggest that substantial differences in adult survival largely due to wolf predation are likely to lead to long‐term decline of woodland caribou in the commercially logged landscape, whereas the unlogged landscape should be considerably more capable of sustaining caribou. Estimates of population growth rates (λ ) for the 2010–2014 period differed little between the matrix model and the individual‐based PVA model for the unlogged (matrix model 
*This image is copyright of its original author
 = 1.01; individual‐based model 
*This image is copyright of its original author
 = 0.98) and logged landscape (matrix model 
*This image is copyright of its original author
 = 0.88; individual‐based model 
*This image is copyright of its original author
 = 0.89). We applied the spatially explicit PVA model to assess the viability of woodland caribou across 14 woodland caribou ranges in Ontario. Outcomes of these simulations suggest that woodland caribou ranges that have experienced significant levels of commercial forestry activities in the past had annual growth rates <0.89, whereas caribou ranges that had not experienced commercial forestry operations had population growth rates >0.96. These differences were strongly related to regional variation in wolf densities. Our results suggest that increased wolf predation risk due to anthropogenic disturbance is of sufficient magnitude to cause appreciable risk of population decline in woodland caribou in Ontario. © 2020 The Authors. The Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.
1 user Likes Sully's post
Reply

United Kingdom Sully Offline
Ecology & Rewilding
*****
#36

Inconsistent detection of extinction debts using different methods

Abstract:

The extinction debt, delayed species extinctions following landscape degradation, is a widely discussed concept. But a consensus about the prevalence of extinctions debts is hindered by a multiplicity of methods and a lack of comparisons among habitats. We applied three contrasting species–area relationship methods to test for plant community extinction debts in three habitats which had different degradation histories over the last century: calcareous grassland, heathland and woodland. These methods differ in their data requirements, with the first two using information on past and current habitat area alongside current species richness, whilst the last method also requires data on past species richness. The most data‐intensive, and hence arguably most reliable method, identified extinction debts across all habitats for specialist species, whilst the other methods did not. All methods detected an extinction debt in calcareous grassland, which had undergone the most severe degradation. We conclude that some methods failed to detect an extinction debt, particularly in habitats that have undergone moderate degradation. Data on past species numbers are required for the most reliable method; as such data are rare, extinction debts may be under‐reported.
2 users Like Sully's post
Reply

United Kingdom Sully Offline
Ecology & Rewilding
*****
#37

Carnivoran postcranial adaptations and their relationships to climate

Abstract:

The relationship between climate and morphology is important to understand in view of the rapid rate of climate change occurring today; however, this relationship has not been fully explored in many mammalian groups. We use postcranial indices to explore the association between climate and morphology in the mammalian order Carnivora. Carnivora is a good group to use for this analysis because it includes species with a variety of locomotor ecologies that live in almost every type of habitat on Earth. We measured postcrania of 121 carnivoran species from around the world, combined with habitat and climate data from the BIOCLIM database and the NCEAS Paleocommunities Working Group to examine correlations between postcrania, temperature and precipitation. We analyzed these data using correspondence analysis and multiple linear regressions. We found three postcranial indices that were significantly correlated with climate. Brachial index (radius/humerus) and shoulder moment (length deltopectoral crest/length humerus) were both significantly associated with temperature and precipitation, while greater trochanter height (as proportion of femur length) was associated with precipitation. We found that these indices were indirectly related to climate via the strong association between climate and locomotor ecologies. This relationship between climate and postcranial proportions can be used in future studies: for paleo‐climate reconstruction in carnivore localities and for trait‐based identification of species vulnerability as climate change continues.
Reply

United Kingdom Sully Offline
Ecology & Rewilding
*****
#38

Of the world’s three largest tropical rainforests, the Congo river basin is the only remaining strong net carbon sink. SE Asia has already become a source. Amazon river basin teeters on the edge.

https://wri.org/blog/2021/01/forests-carbon-emissions-sink-flux


*This image is copyright of its original author
1 user Likes Sully's post
Reply

United Kingdom Sully Offline
Ecology & Rewilding
*****
#39

Historical and current distribution ranges and loss of mega-herbivores and carnivores of Asia


Abstract:
Ecosystem functioning is dependent a lot on large mammals, which are, however, vulnerable and facing extinction risks due to human impacts mainly. Megafauna of Asia has been declining for a long, not only in numbers but also in their distribution ranges. In the current study, we collected information on past and current occurrence and distribution records of Asia’s megafauna species. We reconstructed the historical distribution ranges of the six herbivores and four carnivores for comparison with their present ranges, to quantify spatially explicit levels of mega-defaunation. Results revealed that historically the selected megafauna species were more widely distributed than at current. Severe range contraction was observed for the Asiatic lion, three rhino species, Asian elephant, tigers, and tapirs. Defaunation maps generated have revealed the vanishing of megafauna from parts of the East, Southeast, and Southwest Asia, even some protected Areas losing up to eight out of ten megafaunal species. These defaunation maps can help develop future conservation policies, to save the remaining distribution ranges of large mammals.
2 users Like Sully's post
Reply






Users browsing this thread:
1 Guest(s)

About Us
Go Social     Subscribe  

Welcome to WILDFACT forum, a website that focuses on sharing the joy that wildlife has on offer. We welcome all wildlife lovers to join us in sharing that joy. As a member you can share your research, knowledge and experience on animals with the community.
wildfact.com is intended to serve as an online resource for wildlife lovers of all skill levels from beginners to professionals and from all fields that belong to wildlife anyhow. Our focus area is wild animals from all over world. Content generated here will help showcase the work of wildlife experts and lovers to the world. We believe by the help of your informative article and content we will succeed to educate the world, how these beautiful animals are important to survival of all man kind.
Many thanks for visiting wildfact.com. We hope you will keep visiting wildfact regularly and will refer other members who have passion for wildlife.

Forum software by © MyBB