Habitat Loss Research Articles

Population viability analysis on the Iranian endangered goat breeds

Because of the downward trend of breeding goats and flocks, habitat loss, using other breeds in reproduction, and the presence of survival-threatening factors, Iranian goat breeds, including Markhoz, Adani, and Najdi, are considered endangered populations. This research aims to investigate the current status and provide the necessary information to conserve these three endangered populations. For this purpose, the census data and the required parameters were collected from the available resources and flocks during the years of the project implementation. Then, two scenarios, the past and future dynamics of the population assuming continuing existing conditions, were simulated using the population viability analysis (PVA) method. Finally, the sensitivity analyses of parameters affecting the viability criteria were done. PVA was conducted using the Vortex simulation program version 10.5.6. The past dynamics simulation of the population showed that the biological parameters and assumptions used in the model have valid and reliable values and frequencies, and they can be used in the simulation of different management scenarios. Based on this scenario, the inbreeding rates (∆F) for the Markhoz and Adani populations have reached above the critical level of 0.5%. The future dynamics simulation of the population showed that the process of increasing inbreeding and decreasing genetic diversity would accelerate, and the breeds' extinction probability would start in 2026, 2033, and 2031 for Markhoz, Adani, and Najdi, respectively. The mean time to the first extinction was also 15.4 ± 2.53, 26.68 ± 3.75, and 13.96 ±1.78 years, respectively. The sensitivity analyses indicated that adult does overharvest, the frequency of feed limitation, and competition with other breeds had the highest effect on the population viability criteria of the investigated breeds. Markhoz, Najdi, and Adani goats need urgent conservation measures. The results obtained in this research may prepare a suitable framework for providing conservation programs.

The loss of forest gaps, changes of vegetation and wild bee communities from 1975 to 2020 – increasing numbers of endangered wild bee species despite negative habitat trends in the Danube valley

This study investigated how structural changes of a historical traditionally used forest landscape in Central Europe have affected traits of vegetation and wild bee communities. We compared the extent of gaps in the forest using aerial photographs between 1945 and 2020. And we found historic vegetation and bee surveys from 1975 and 1990, which we repeated in 2010 and 2020. We characterised the vegetation of the closed forest, the forest gaps and the small-scale meadows adjacent to the forest as well as the wild bee community by traits and investigated trait changes with Kruskal-Wallis tests. By NMDS we characterised sample plots and transect walks of timepoints with traits and species. Area of forest gaps decreased by 88% from 1945 to 2020 and by 74% from 1975 to 2020. In the traits of vegetation, Ellenberg Indicator Values (EIV) for moisture and soil nutrients significantly increased in closed forest, forest gaps and meadows adjacent to forest. The EIVs for light and temperature, and the number of red list species decreased. The number of wild bee species that specialise in visiting flowers with long tubes and hylophilic species declined. The number of eremophilic species, species with longer phenologies, and recently Red list species increased. In the NMDS figure of forest gaps and of adjacent meadows, different species and traits characterised more recent and older sample plots of vegetation and confirm the results of the Kruskal Wallis tests. Wild bee communities of 2010 and 2020 were characterised by frequent species, while those of 1975 and 1990 were not characterised by any species. The traits characterised the wild bee communities of the older and younger transect walks in accordance with the results of the Kruskal Wallis tests. In addition, oligolectic bees characterised the older transect walks. The loss of forest gaps represents a direct loss of habitat for many plant and wild bee species. In addition, the qualitative changes in vegetation indicate a deterioration in habitat quality for plants of open forests and wild bees. Among wild bees, specialists were negatively affected by the changes described. These developments were reflected in the initial downward trend in Red List bee species. The increase in bee species with longer phenology, in eremophilic species, the decrease in hylophilic species, and the recent increase in red-listed species can indicate climate change. Therefore, this study underlines the importance of the preservation and development of ecologically valuable forest gaps, particularly in historical traditionally used forests with a typical species composition.

Hematological and plasma profiles and ticks and tick-borne pathogens in wild Formosan black bears (Ursus thibetanus formosanus)

BackgroundThe endangered Formosan black bear (Ursus thibetanus formosanus) is the largest native carnivorous mammal in Taiwan. Diseases, poor management, illegal hunting, and habitat destruction are serious threats to the survival of bear populations. However, studies on the impact of diseases on bear populations are limited. Therefore, this study aimed to establish a database of the hematological and plasma profiles of free-ranging Formosan black bears and investigate the occurrence of ectoparasites, blood parasites, and vector-borne pathogens.MethodsFormosan black bears were captured in Yushan National Park (YNP) and Daxueshan Forest Recreation Area (DSY) in Taiwan. Blood samples were collected from each bear for hematological analysis and plasma biochemistry using a hematology analyzer. Parasites and pathogens were detected using a thin blood smear with Wright–Giemsa staining and polymerase chain reaction (PCR) assay. Additionally, macroscopic ectoparasites were collected from bears to detect blood parasites and other pathogens. Moreover, the relationships between the bear variables (sex, age, and occurrence of parasites or pathogens), ectoparasites, and infectious agents were also analyzed.ResultsIn all, 21 wild bears (14 in YNP and 7 in DSY) were captured and released during the satellite tracking studies. Hematological analysis and plasma biochemistry indicated significant differences in white blood cells (WBC), segments, creatine kinase (CK), and lactate dehydrogenase (LDH) levels between foot snare and culvert-captured bears. Additionally, there were significant differences in total plasma protein (TPP), creatinine, Ca2+, Mg2+, and K+ levels between male and female bears. Moreover, pathogen-infected bears had significantly higher erythrocyte sedimentation rate (ESR; 30 min and 1 h) and globulin levels than uninfected bears. In total, 240 ticks were collected from 13 bears, among which eight adult tick species were identified, including Haemaphysalis flava, Haemaphysalis hystricis, Amblyomma testudinarium, Ixodes ovatus, Dermacentor taiwanensis, Haemaphysalis longicornis, Ixodes acutitarsus, Amblyomma javanense, and nymphs belonging to Haemaphysalis spp. PCR revealed that 13 (61.90%) and 8 (38.10%) bears harbored Hepatozoon ursi and Babesia DNA, respectively. Among the ticks examined, 157 (65.41%) and 128 (53.33%) samples were positive for H. ursi and Babesia, respectively.ConclusionsTo the best of our knowledge, this is the first study to establish a database of the hematological and plasma profiles of wild Formosan black bears and investigate ectoparasite infestation and Hepatozoon and Babesia spp. infection. In conclusion, these findings may serve as a reference for monitoring the health and population of locally endangered bears.Graphical

Time-lag effects of habitat loss, but not fragmentation, on deadwood-dwelling lichens

ContextLandscape habitat amount is known to increase biodiversity, while the effects of habitat fragmentation are still debated. It has been suggested that negative fragmentation effects may occur with a time lag, which could explain inconsistent results. However, there is so far no empirical support for this idea.ObjectivesWe evaluated whether habitat amount and fragmentation at the landscape scale affect the species density of deadwood-dwelling lichens, and whether these effects occur with a time lag.MethodsWe surveyed deadwood-dwelling lichens in woodland key habitats in two regions in northern Sweden, and modelled their species density as a function of past (1960s) and present (2010s) habitat amount (old forest area) and fragmentation (edge density) in the surrounding landscapes.ResultsPresent habitat amount generally had weak positive effects on lichen species density. Positive effects of the past habitat amount were stronger, indicating a time lag in habitat amount effects. Habitat fragmentation effects were generally weak and similar whether fragmentation was measured in the past or the present landscapes, indicating no time lag in fragmentation effects.ConclusionsWe found a time lag effect of habitat amount, but not fragmentation. This result is not consistent with suggestions that time lags explain the mixed observations of fragmentation effects. Time-lag effects of habitat amount suggest that the studied lichen communities face an extinction debt. Conservation should therefore prioritize increasing the amount of old forest, for example by creating forest reserves, to maintain the current lichen diversity. More generally, our results imply that studies examining only the present habitat amount risk under-estimating its importance.

Morphology, Reproductive Biology and Anatomy of the Foxtail Orchid, Rhynchostylis retusa (L.) Blume

Background: Rhynchostylis retusa (L.) Blume, commonly known as the fox-tail orchid, is a promising epiphytic native species for breeding programs. Its’ population is diminishing in the native habitat due to unscrupulous overexploitation and habitat destruction. Hence, conservation of this species attains prime importance. To achieve the foregoing task, phenotypic traits in relation to adaptation are to be elucidated. Methods: In the present investigation, the morphological characters were documented and the correlation between each trait was determined. Furthermore, the anatomy of leaves and roots was documented, as was the stomatal structure and distribution on the abaxile and adaxile surfaces of the leaves. Biometric features of floral characters and reproductive biology such as anthesis, stigma receptivity, pollen production per pollinium, pollen viability, pollination mechanisms, self and cross-compatibility; male sterility, etc. were studied and documented. Observations on capsule development, nature of seeds, seed viability, etc. were also determined. Result: The seed viability tests revealed that about 40% of the seeds are viable. The observations gathered during this investigation can be used to develop conservation, sustainable utilization and genetic improvement strategies for this crop.

Coastal Zone Management in Response to Sea Level Rise in the 21st Century: A Study from Hurst Spit to Lymington, South England

This study examines the coastal region spanning from Hurst Spit to the mouth of the Lymington River along the Western Solent coast in Hampshire, South England. The area comprises critical habitats for international bird species on the seaward side and is protected by a seawall on the landward side. Rising sea levels pose a significant threat to this area, including habitat loss and potential seawall breaches. To address the uncertainty in sea level rise projections for the 21st century, this study utilises data processing in ArcGIS, including LiDAR data, tidal data, and sea level rise projections. It adopts contingency allowances for sea level rise, resulting in a projected 0.89 metre by 2100. Analysis reveals a significant transformation in habitat distribution, with standing water and mudflats expanding while salt marshes and dry land areas diminish. Salt marsh areas are projected to contract by 64.6%, with the pioneer salt marsh facing the greatest loss. The report recommends a proactive approach, including realigning the seawall in vulnerable areas, allowing for the creation of new salt marshes. This managed intervention strategy can reduce habitat loss to approximately 17.43%, mitigating the potential ecological and human habitat impacts of rising sea levels in that region.

Loss and gain of marine biodiversity in Mediterranean seawaters

The Mediterranean Sea is one of the most important biodiversity hotspots worldwide. The high biodiversity level of the basin is confirmed by the presence of about 17,000 marine species of which 20.2% are endemics. Amongst them, Posidonia oceanica (Linnaeus) Delile can form, in pristine coastal waters, large and extensive meadows, performing a pivotal role in endemic processes. However, the richness of marine biota is, actually, affected by some threats such as habitat loss, marine pollution, climate changes, eutrophication and the establishment of invasive alien species coming from the Indo-Pacific region through the pathway of Suez Canal. This trend could lead to a new kind of marine biodiversity influenced by the introduction of termophilic species altering the pattern of Mediterranean biota. Anyway, it is necessary a global approach, ensuring the better ecological conditions so to protect marine biodiversity in meditrranean seawaters.

Multi-decadal floodplain classification and trend analysis in the Upper Columbia River valley, British Columbia

Abstract. Floodplain wetland ecosystems experience significant seasonal water fluctuation over the year, resulting in a dynamic hydroperiod, with a range of vegetation community responses. This paper assesses trends and changes in land cover and hydroclimatological variables, including air temperature, river discharge, and water level in the Upper Columbia River Wetlands (UCRW), British Columbia, Canada. A land cover classification time series from 1984 to 2022 was generated from the Landsat image archive using a random forest algorithm. Peak river flow timing, duration, and anomalies were examined to evaluate temporal coincidence with observed land cover trends. The land cover classifier used to segment changes in wetland area and open water performed well (kappa of 0.82). Over the last 4 decades, observed river discharge and air temperature have increased, precipitation has decreased, the timing of peak flow is earlier, and the flow duration has been reduced. The frequency of both high-discharge events and dry years have increased, indicating a shift towards more extreme floodplain flow behavior. These hydrometeorological changes are associated with a shift in the timing of snowmelt, from April to mid-May, and with seasonal changes in the vegetative communities over the 39-year period. Thus, woody shrubs (+6 % to +12 %) have expanded as they gradually replaced marsh and wet-meadow land covers with a reduction in open-water area. This suggests that increasing temperatures have already impacted the regional hydrology, wetland hydroperiod, and floodplain land cover in the Upper Columbia River valley. Overall, there is substantial variation in seasonal and annual land cover, reflecting the dynamic nature of floodplain wetlands, but the results show that the wetlands are drying out with increasing areas of woody/shrub habitat and loss of aquatic habitat. The results suggest that floodplain wetlands, particularly marsh and open-water habitats, are vulnerable to climatic and hydrological changes that could further reduce their areal extent in the future.

Optimising the reintroduction of a specialist peatland butterfly Coenonympha tullia onto peatland restoration sites

Abstract The two main goals of peatland restoration are habitat improvement and climate change mitigation by reducing greenhouse gas emissions from damaged peatlands and providing a net carbon sink. The biodiversity of specialist peatland species is threatened because of habitat destruction and the large heath butterfly Coenonympha tullia has become a flagship species for peatland ecosystem restoration, with a species reintroduction programme currently underway on a peatland restoration site within Chat Moss, Greater Manchester, UK. The aim of this study was to improve our quantitative understanding of C. tullia habitat resource requirements to optimise habitat restoration for further reintroduction attempts. We monitored butterfly micro-distribution and dispersal during the first three flight seasons (2020, 2021 and 2022) of the reintroduction using high-accuracy GPS, combined with a distance-bearing protocol. Analysis of butterfly flight points and rest points in relation to plant species distribution and abundance, identified the most important habitat resources. Using logistic regression, treatment-response curves were constructed, enabling us to identify critical thresholds for the abundance of these important habitat resources. The break of slope near the top of the logistic curve was identified using segmented regression, giving an estimate of the near-optimal abundance; fourteen Eriophorum vaginatum tussocks per 2 m quadrat and 13.4% Erica tetralix cover. Implications for insect conservation During ecosystem restorations, prior to the reintroduction of species with specialist habitat requirements, it is necessary to have a clear understanding of the abundance of the important habitat resources that need to be provided. The quantitative approach we describe defines the most significant environmental factors and habitat resources, then uses segmented regression to estimate the near-optimal habitat resource requirements; increasing the likelihood of reintroduced populations thriving and reintroduction programmes achieving long-term success.

Investigating Endemic Species Conservation Hotspots Based on Species Distribution Models in Swat Region, Hindu Kush Pakistan

For the effective conservation of plant species, it is imperative to manage habitat loss and fragmentation by establishing a protected area network that comprehensively encompasses their habitat. In this study, we identified the suitable habitats for some endemic plant species in the Swat District, Pakistan, to conduct a thorough analysis of proposed protected areas (hotspot areas). Utilizing data from a recent botanical survey, environmental parameters from World-Clim, and various other sources, we determined the habitat of each species using the MaxEnt species distribution model. The modeled habitat suitability for each species were combined to generate maps illustrating endemic richness (hotspots), as well as to prioritize areas based on conservation value and habitat suitability. Future climate projections spanning from 2000 to 2050 were acquired from the WorldClim database Nineteen bioclimatic variables were assessed, incorporating data from three global climate models: CCSM4, HadGEM2-AO, and MPI-ESM-LR. We modeled seven endemic species from the Swat District and, by combining their maps, found three hotspot areas which show more environmental suitability under future climatic conditions. The future model forecasts a significant decrease in population density by the year 2050. Currently, these species exhibit their highest density along the eastern and southern borders of the valley, particularly in the Karakar, Elum border, Mankial Kalam, and Gabral Kalam areas. The anticipated alterations in density and distribution could have a considerable impact not only on the tree species but also on the associated sub flora.

Food resource partitioning between males and females of Volcano Sunbird (Cinnyris preussi) on Mount Cameroon

AbstractCompetition for nectar is expected to result in feeding niche differentiation. Here, we targeted the sexually size-dimorphic Volcano Sunbird (Cinnyris preussi) on Mount Cameroon. We investigated whether males and females feed on different plant species, whether females with shorter bills than males prefer shorter flowers, and whether larger dominant males visit more energetic flowers that produce higher amounts of nectar sugars. We also asked whether feeding niches were spatially separated along the elevation gradient and whether this separation varied between the two contrasting seasons. We collected data on the frequency of visits to individual plant species and analyzed the male-to-female ratios in the mist-netted dataset. In addition, we estimated production of nectar sugar in individual habitats and seasons. Despite the large dataset collected, encompassing 6476 bird–plant interactions, our findings did not provide evidence of differences in the spectra of the visited plant species. In addition, females did not visit flowers with shorter tubes, nor did males visit flowers that produced higher amounts of sugars. However, we observed a sex-specific dispersion of sunbirds during the wet season. During the dry breeding season, both males and females feed mainly in nectar-rich montane and submontane forests. In the wet season, the production of nectar sugar in these habitats decreased dramatically, and females largely disappeared. In contrast, female activity increased in the lowest and highest parts of the altitudinal range. Our findings on elevational movements are important in the current context, in which species face potential threats from habitat destruction and climate change.

Population status of a nocturnal primate (the Philippine tarsier – Carlito syrichta, Linnaeus, 1758) in an agricultural area of Subayon, Bilar, Bohol

Abstract The destruction of wildlife habitats due to the exponential growth of human population and its encroachment into wild areas is a major threat to many species around the world. In order to understand the effects of human disturbance on the Philippine tarsier (Carlito syrichta), we evaluated its population status by quantifying the species’ population density in an agricultural habitat and assessed the degree of human disturbance in the area. We did the study in Subayon, Bilar, Bohol, where we surveyed 32 ha out of the total 115 ha of the village between April and June 2017. We predominantly used vocal activity to identify the presence and absence of tarsiers, supplementing the data with incidental sightings. In addition, human disturbances were assessed and described qualitatively. We estimated the population density on 75 individuals per square kilometer. The human disturbance was evidenced in 28 out of 32 plots, which indicates that the entire area has already been disturbed. This study showed that the Philippine tarsier could inhabit highly altered habitats such as agricultural landscapes and suggest that Subayon village might be important for the conservation of this species. We provided another example of the ecological flexibility of otherwise specialised nocturnal primates able to inhabit agricultural areas. To avoid conflicts with humans and to conserve such a species in the future, education, outreach and active involvement of local people are essential.

Forest conversion and timber certification in the public plantation estate of NSW: Implications at the landscape and policy levels

This paper investigates the clearance of native forests and native vegetation for plantation establishment, otherwise known as forest conversion, in the state-owned plantations of New South Wales, Australia. It begins by describing Australia’s forests, plantations, and forest conversion, continues with an outline of the history of public hardwood plantations in New South Wales, and explores the regulatory frameworks that allow this practice to happen, and the responses adopted by non-state environmental governance systems, notably forest certification, to address this problem. The paper presents a case study analysis of conversion in the hardwood plantations of northern NSW, and concludes that the current regulatory environment facilitates deforestation, with cumulative impacts at the landscape level, and that without government intervention, efforts to prevent this by non-state action will only be partially successful, leading to ongoing habitat and species loss. The failure of existing legislative and regulatory frameworks to adequately acknowledge, define, and prohibit conversion will remain an impediment to sustainable forest management, as the entry of such timber into the market contaminates supply chains, resulting in considerable reputation risk. Reform is needed in both public and private governance systems to ensure strong governance, effective planning, and ecosystem integrity at the landscape level. Recommendations are provided for policymakers.

Genotyping-by-Sequencing Study of the Genetic Diversity and Population Structure of the Endangered Plant Tsoongiodendron odorum Chun in China

Tsoongiodendron odorum Chun is a large evergreen tree in the Magnoliaceae family and an ancient relict species represented by small wild populations. It has excellent material quality, high ornamental value, and scientific significance. However, due to the complicated natural reproduction and notable habitat destruction, its wild populations must be urgently conserved. We used genotyping-by-sequencing to examine 17 natural populations of T. odorum in China, the species’ primary habitat, to better understand the genetic diversity of this species and use its germplasm resources. T. odorum had a very low level of genetic diversity; its mean values for Ho, He, Pi, and PIC were 0.175, 0.123, 0.160, and 0.053, respectively. With an average within-population Fst of 0.023 and an inter-population gene flow Nm of 10.918, population genetic variation was primarily found within populations, demonstrating minute genetic divergence between populations. The 17 natural populations of T. odorum were divided into two major categories: the Fujian populations in eastern China and the Jiangxi, Guangdong, Hunan, and Guangxi populations in central and western China. Our research contributes to the understanding of T. odorum’s genetic diversity and organization and offers a theoretical framework for the species’ conservation, breeding, and selection.

Diversity of Wild Vegetables of Sandwip Island in Chittagong, Bangladesh

An extensive investigation on the diversity of wild edible vascular plants of Sandwip Island in Chittagong district, Bangladesh has been conducted during August 2008 to September 2011. The present study has revealed a total of 39 species of wild edible vascular plants under 27 genera in 19 families. The people used various wild vascular plant parts like leaves, stem, fruit etc. as a source of food in the studied area. Many rural people of the area are mostly dependent on wild vascular plants as their source of vegetables in their daily life. But, the wild vegetable resources of the area are decreasing day by day due to excessive collection of plants and habitat destruction. So, a documentation of these plant resources is needed in order to domesticate them for sustainable use. The Chittagong Univ. J. B. Sci.,Vol. 7(1 &2):11-20, 2012

The Recolonisation of the Piketberg Leopard Population: A Model for Human–Wildlife Coexistence in a Changing Landscape

Important metapopulation dynamics are disrupted by factors such as habitat loss, climate change, and human-induced mortality, culminating in isolated wildlife populations and threatening species survival. Source populations, where birth rates exceed mortality and connectivity facilitates dispersal, contrast with sink populations, where mortality outstrips births, risking localised extinction. Recolonisation by individuals from source populations is pivotal for species survival. The leopard is the last free-roaming apex predator in South Africa and plays an important ecological role. In the Eastern and Western Cape provinces in South Africa, leopard populations have low densities and fragmented population structures. We identified a leopard population that, after being locally extinct for a century, appeared to recolonise an ‘island’ of mountainous habitat. We aimed to understand potential factors driving this recolonisation using recent camera trapping surveys and historical statutory destruction permits. We employed spatially explicit capture–recapture (SECR) methods to estimate the leopard density and explore potential factors which best explain density. We found that the recently recolonised Piketberg population now exhibits some of the highest densities reported in the region (~1.8 leopards/100 km2; CI 1.4–2.5). Livestock, human presence, elevation, and the camera trap grid appeared to explain leopard detection rates. When considering the historic data, the re-emergence of leopards in the Piketberg coincided with the cessation of the extensive state-sponsored and state-enabled culling of the species, and the change in land use from livestock production to crop agriculture, which likely contributed to the recolonisation. Elucidating these factors deepens our understanding of leopard metapopulation dynamics in relation to land use and species management and highlights the crucial role of private land and state agencies and associated policies in species persistence.

Status and impacts to sea turtles in Vietnam

Sea turtles face a great danger of extinction because of human impacts, and the number of turtle occurrence is decreasing. By interviewing fishermen, coastal residents and authorities combined with field surveys in some places where turtles regularly lay eggs, such as Con Dao and Ninh Thuan, the results show that 05 species of sea turtles were found in Vietnam: The Green (Chelonia mydas), Hawksbill (Eretmochelys imbricata), Olive Ridley (Lepidochelys olivacea), Loggerhead (Caretta caretta) and Leatherback (Dermochelys coriacea). Among them, Green turtles are the most abundant and distributed in all surveyed localities; Hawksbill and Olive Ridley were smaller in number; and Loggerhead and Leatherback were the two species with the least number. Only 03 species remaining to breed on the beaches: Green, Olive Ridley, and Leatherback. The Hawksbill turtles used to lay eggs in the past but have been no longer recorded. Con Dao is a home for the largest number of breeding Green turtles. The reasons for the decline of turtles in Vietnam were the collection of eggs and nesting turtles, fisheries bycatch, development of coastal infrastructure and waste pollution, habitat degradation, and illegal trade in sea turtle products.

Human-Induced Range Expansions Result in a Recent Hybrid Zone between Sister Species of Ducks

Landscapes are consistently under pressure from human-induced ecological change, often resulting in shifting species distributions. For some species, changing the geographical breadth of their niche space results in matching range shifts to regions other than those in which they are formally found. In this study, we employ a population genomics approach to assess potential conservation issues arising from purported range expansions into the south Texas Brush Country of two sister species of ducks: mottled (Anas fulvigula) and Mexican (Anas diazi) ducks. Specifically, despite being non-migratory, both species are increasingly being recorded outside their formal ranges, with the northeastward and westward expansions of Mexican and mottled ducks, respectively, perhaps resulting in secondary contact today. We assessed genetic ancestry using thousands of autosomal loci across the ranges of both species, as well as sampled Mexican- and mottled-like ducks from across overlapping regions of south Texas. First, we confirm that both species are indeed expanding their ranges, with genetically pure Western Gulf Coast mottled ducks confirmed as far west as La Salle county, Texas, while Mexican ducks recorded across Texas counties near the USA–Mexico border. Importantly, the first confirmed Mexican × mottled duck hybrids were found in between these regions, which likely represents a recently established contact zone that is, on average, ~100 km wide. We posit that climate- and land use-associated changes, including coastal habitat degradation coupled with increases in artificial habitats in the interior regions of Texas, are facilitating these range expansions. Consequently, continued monitoring of this recent contact event can serve to understand species’ responses in the Anthropocene, but it can also be used to revise operational survey areas for mottled ducks.

Using proxy data and vegetation modelling to predict past, current and future distributional shifts of Butea monosperma, a marker of land degradation in India

Extensive deviations in spatio-temporal social and environmental dynamics currently alter the health of ecosystems and the services they provide. Detecting the causes that contribute to the distribution of a natural forest species capable of restoring the lost ecosystem function and productivity will aid in determining better food security, livelihoods and provision of ecosystem goods and services. We modelled the spatial range of Butea monosperma (B. monosperma) under past, that is, Last Glacial Maximum (LGM), Middle Holocene (MH), current and future (2070) climatic scenarios with Maximum Entropy (MaxEnt) trained on present-day occurrences. We identified areas of suitable habitats for which the estimation of habitat stability is predicted in all the models at different times. To validate the inferred suitable habitat, we tested the model by the current occurrence and fossil pollen data of B. monosperma. Our distribution models agree with the fossil pollen records for the MH (4,500–7,000 yr BP) and predict the prevalence of B. monosperma covering 84.22% of the Indian subcontinent with maximum habitat stability in western and southwestern India (10.95%). The widespread potential distribution of the plant species during the LGM supports the presence of the last remnants of tropical dry deciduous forest in the region. However, a decline in habitat suitability (62.84%) is predicted under current and future climatic scenarios with maximum stability (0.90%–3.09%) along the Western Ghats, Nilgiri hills, Gir range in the western India and north-eastern region covering the Assam Valley and foothills of Tripura and Mizo hills. Temperature seasonality (33.6%) measured in terms of variable contribution in MaxEnt model significantly affects the distribution shift of B. monosperma, along with annual precipitation (22.8%) and annual mean temperature (16.2%). Model results provide evidence of habitat reduction and identify the stability hotspots for B. monosperma for its conservation and establishment of land management policies mainly for the dry tropics.

The Impact of Land Conversion on Primate Habitats: Refining the Extent of Occurrence Data for Four Capuchin Species in North and Northeastern Brazil

AbstractConversion of primate forest habitat is a global concern with significant implications for primate populations. Although the geospatial Extent of Occurrence (EOO) data provided for primates by the International Union for the Conservation of Nature are widely used, they do not accurately reflect the existing extent of primate species because of ongoing habitat loss. We focused on four capuchin monkey species (Sapajus apella, S. flavius, S, libidinosus, and S. xanthosternos), all native to North and Northeastern Brazil, to prioritize research by the Capuchin Action Network. We refined the EOOs for the four primate species using MapBiomas land cover data. We accounted for areas of agriculture, urban, and mining and updated the EOOs of the four species. Additionally, we evaluated the Conservation Units in each EOO. Conservation Units are protected areas critical to mitigating habitat loss in Brazil. Our results show that S. apella has lost the smallest amount of its EOO (13%), while S. flavius has lost the most (77%). Agriculture was the leading cause of land cover change, followed by urbanization and mining. We provide an updated EOO for the four capuchin species and highlight the need for conservation efforts to address the challenges posed by human activities in the capuchin species’ habitats.