Habitat connectivity of threatened ungulate species in a native savanna landscape of northern South America

Mammalian Biology, Journal Year: 2024, Volume and Issue: 104(3), P. 259 - 275

Published: April 22, 2024

Abstract The native savanna ecosystem of the Orinoquia region is habitat 50% wild ungulate species reported for Colombia. Over last 20 years, this high diversity has been strongly threatened by human transformation natural land cover causing connectivity loss habitats. lacks a biological analysis with multi-species approach involving groups that are representative such as ungulates. Understanding spatial distributions suitable areas and main habitats act primary in these landscapes fundamental design conservation strategies. We use an occurrence dataset lowland tapir ( Tapirus terrestris ), white-tailed deer Odocoileus virginianus white-lipped peccary Tayassu pecari ) development species’ potential distribution models, binarization process, morphological pattern analysis. This information was used modeling dispersal corridors connecting core focal using randomized shortest path algorithm quantifying weighted global metrics. Our results suggest integral corridor least-cost routes between landscape on middle basins rivers Meta River. These associated fluvial dendritic systems connected, while eastern part disconnected. discuss how application knowledge ecology might improve management metapopulations region.

Language: Английский

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Beyond the “empty forest”: The defaunation syndromes of Neotropical forests in the Anthropocene

Global Ecology and Conservation, Journal Year: 2022, Volume and Issue: 41, P. e02362 - e02362

Published: Dec. 29, 2022

Human activities have altered the abundance and distribution of animals, reshaping ecosystems into novel generally more depauperate configurations. Whereas, overhunting habitat loss threaten numerous species, predation release subsidies from agriculture food waste benefit others. Although these impacts combined can generate multiple different outcomes, we propose that, depending on prevalence anthropogenic drivers, mammalian communities are pushed towards one three main defaunation syndromes: Herbivore-dominated, seed predator-dominated or mesopredator-dominated systems. The extirpation top predators favors herbivore-dominated assemblages, while eliminate large-bodied herbivores, resulting in dominance smaller-bodied mesopredators. Within fragmented landscapes where absent, systems emerge supported by surrounding agricultural matrix. Based a large dataset camera-trap studies, show that continuous Neotropical forests with exhibit greater balance between guilds landscape structure explain composition variation according to syndromes. guild over others has profound effects ecological processes, threatening ecosystem services human health may be dominant scenario Anthropocene.

Language: Английский

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Impending anthropogenic threats and protected area prioritization for jaguars in the Brazilian Amazon

Communications Biology, Journal Year: 2023, Volume and Issue: 6(1)

Published: Feb. 15, 2023

Abstract Jaguars ( Panthera onca ) exert critical top-down control over large vertebrates across the Neotropics. Yet, this iconic species have been declining due to multiple threats, such as habitat loss and hunting, which are rapidly increasing New World tropics. Based on geospatial layers, we extracted socio-environmental variables for 447 protected areas Brazilian Amazon identify those that merit short-term high-priority efforts maximize jaguar persistence. Data were analyzed using descriptive statistics comparisons of measures central tendency. Our results reveal containing largest densities estimated population sizes precisely among confronting most anthropogenic threats. threatened in world’s tropical forest biome by deforestation associated with fires, subsequent establishment pastures. By contrasting highest threats a bivariate plot, provide shortlist top-10 should be prioritized immediate conservation 74 action. Many these located at frontier or important boundaries neighboring countries (e.g., Peruvian, Colombian Venezuelan Amazon). The predicament safe future jaguars can only ensured if persist resist downgrading downsizing both external geopolitical pressures infrastructure development frail law enforcement).

Language: Английский

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Prevalence and Antimicrobial Resistance of Campylobacter jejuni and Campylobacter coli in Wild Birds from a Wildlife Rescue Centre

Animals, Journal Year: 2022, Volume and Issue: 12(20), P. 2889 - 2889

Published: Oct. 21, 2022

Climate change, excessive exploitation of agricultural land which reduces natural habitats, wildlife shooting, and the use pesticides all cause difficulties for wildlife, with considerable numbers animals being brought to rescue centres. Although efforts staff involved in management at these centres usually focus on therapeutic treatments reintroduce them into wild, monitoring pathogens that may be transmitted humans is relevance. Campylobacter (C.) jejuni C. coli are frequently carried by without inducing clinical signs responsible enteric disorders more rarely extra-intestinal disease humans. Farm species poultry, particular, main reservoirs coli, but wild also carriers. The aim this paper was investigate presence birds housed a centre evaluate sensitivity detected strains antibiotics. found 52 out 209 (24.88%) from 33 different species. prevalent, while only three Long-eared Owls (Asio otus). incidence infection particularly high (72.22%) among omnivorous Infection rates were higher indoors (57.14%) than outdoors (31.74%). Moreover, not whose mean temperature body below 40 °C or 42.2 °C. most common antibiotic resistance tested against trimethoprim/sulfamethoxazole, ciprofloxacin enrofloxacin. In addition, multi-drug found. results highlight need increase biosecurity measures so as reduce health-related risks workers management.

Language: Английский

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Drivers and spatial patterns of avian defaunation in tropical forests

Diversity and Distributions, Journal Year: 2024, Volume and Issue: unknown

Published: May 10, 2024

Abstract Aim Wildlife overexploitation, either for food consumption or the pet trade, is one of main threats to bird species in tropical forests. Yet, spatial distribution and intensity harvesting pressure on birds remain challenging quantify. Here, we identify drivers hunting‐induced declines abundance quantify magnitude extent avian defaunation at a pantropical scale. Location Pantropical. Methods We compiled 2968 estimates hunted non‐hunted sites across tropics spanning 518 species. Using Bayesian modelling framework, fitted species' response ratios set hunting traits. Subsequently, applied our model patterns forests assess biogeographic realms, captured trade consumption. Results Body mass its interactions with hunter accessibility proximity urban markets were most important declines. estimated mean reduction 12% all species, that 43% harbour defaunated communities. Large‐bodied Indomalayan realm displayed greatest Further, moderate high levels extended over 24% forest area, distinct (Brazil, China Indonesia) (SE Asia West Africa). Main Conclusions Our study emphasizes role as major due trapping. further identified hotspots where overexploitation has detrimental effects birds, encompassing local extinction events, thus underscoring urgent need conservation efforts address unsustainable exploitation both subsistence trade.

Language: Английский

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Recent Sociocultural Changes Reverse the Long‐Term Trend of Declining Habitat Availability for Large Wild Mammals in Europe

Diversity and Distributions, Journal Year: 2024, Volume and Issue: 30(12)

Published: Oct. 24, 2024

ABSTRACT Aim People have strongly influenced the biosphere for millennia, but how their increasing activities shaped wildlife distribution is incompletely understood. We examined of European large (>8 kg), wild mammals has changed in association with changing anthropogenic pressures and climate change through Holocene. Location Europe. Methods used over 17,000 zooarchaeological records 20 species spanning 12,000 years to develop time‐calibrated models, incorporating dynamic data on cropland extent, natural vegetation fragmentation, human population density climate. assessed habitat availability potential richness across time within seven biogeographical regions. also compared at record sites present‐day habitats remaining evaluate recent increases coexistence activities. Results found a continuous decline mammal richness, particularly linked changes density. Most loss became evident continentally after 1500 AD, Atlantic Mediterranean bioregions, reached 20% during Iron/Roman Ages (1000 BC–500 AD) due Climate initially boosted (+0.67 species/km 2 average) until end Mesolithic had negligible effects afterward. Today, appear higher coexisting people past (e.g., herbivores today inhabit areas mean 95 people/km , an average 17 period 1500–2000 AD). Main Conclusions Our study emphasizes crucial role determining diversity communities throughout history. Additionally, our results indicate that contemporary trends like land‐use de‐intensification stronger conservation policies can counteract impact past, reverse defaunation.

Language: Английский

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An invasive pathogen generally contracts species to their niche cores, not margins

Ecography, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 28, 2025

Quantifying how species' distributions contract in response to threats can reveal pathways of decline and the role environmental conditions moderating threat impacts. Two general patterns niche contraction have been described: ecological marginalization, where species away from impacts peripheral, sub‐optimal areas their niche, and; core, toward center fitness capacity withstand is highest. Recent work has described widespread marginalization declining mammal species, for which land use change overexploitation are key threats. Different threatening processes could result contrasting contraction, although this not well‐studied. Here, we examine realized Australian frog impacted by emergence chytrid fungus Batrachochytrium dendrobatidis , a pathogen that driven catastrophic amphibian declines globally. We quantified changes space following documented pattern core species. develop apply novel approach show these contractions losses subset space, suggesting population extinctions due factors shaping both (threat impact) host tolerance). Species concentrated high elevation with cooler temperatures, more physiologically suitable constrain resilience hosts at individual levels. Given contrast between our results mammals, propose while given may common among affected vary considerably taxa.

Language: Английский

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Environmental and landscape changes drive medium- to large-bodied mammal species composition across an Amazon-Cerrado ecotone amid the deforestation expansion

Mammalia, Journal Year: 2025, Volume and Issue: unknown

Published: March 18, 2025

Abstract Amazon and Cerrado biomes embrace a vast parcel of Brazilian biodiversity, yet remain understudied in terms species diversity distribution, particularly transitional zones. We investigated the patterns distribution multiples facets medium- to large-bodied mammal across ecotonal Guaporé river basin, including relationship biodiversity variations according landscape-scale features, such as forest remnants agribusiness. sampled fauna via camera-trapping census, six independent sites, totalling sampling effort 540 camera-trap-days 720 h census. also extracted covariables further predicts variation mammalian diversity. Our results revealed that all sites have similar richness, whereas zeta-diversity decline ∼90 % when were compared. Differences richness – even inconspicuous decay shared can be associated environmental gradient distance among evidencing faunistic transictions prompted by rarity endemism regions human-induced landscape changes. The beta-diversity caused turnover-type structure, once ∼66 balanced composition was due changes gradient. Considering imminent threats natural habitats, it is crucial prioritize conservation any habitat given gamma depends on quantity native areas. This strategy serves fundamental cornerstone for maximizing overall tropical forests.

Language: Английский

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A multi-species corridor between the Andean Amazonian and Amazon floodplain landscapes: prioritizing ecological connectivity areas for jaguar and threatened ungulates in the north-eastern of South America

Deleted Journal, Journal Year: 2025, Volume and Issue: 2(1)

Published: April 3, 2025

Language: Английский

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Distribution and structure of African forest elephant trails in anthropogenic savanna-mosaic forest, Gabon

Frontiers in Conservation Science, Journal Year: 2025, Volume and Issue: 6

Published: April 25, 2025

Introduction With increasing human activities, the area affected by humans increases annually and many wild animals are under threat of extinction. On other hand, there serious conflicts between wildlife. In order to mitigate conflicts, it is important understand how perceive balance benefits risks in human-inhabited areas they use land. this study, we investigated African forest elephants ( Loxodonta cyclotis ), which conflict with humans, anthropogenic environments focusing on their trails. Methods This study targeted two parameters environments: vegetation, particularly savannas, have been maintained burning for years, population density, low-density seminatural Within Moukalaba-Doudou National Park, Gabon, an adjacent village, mapped elephant trails compared density structure vegetation (forest savanna) (inside outside national park). Results forest, only 31.4% were well-established exposed ground. savanna, was lower than that forest; however, narrower 65% well established. suggests tend follow specific routes savanna may help them travel more easily, perceiving some risks. The park higher, wider those park, suggesting frequent use. probably due crop fields mango trees attracting elephants. Discussion area, available food be a greater attractant relative risk being threatened humans. findings show trail surveys can carried out inexpensively over short period time. Moreover, clarify land populations, including fine-scale heterogeneous movements.

Language: Английский

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