Potential distribution,absolute density,and population size of Gray‐backed Hawks (Pseudastur occidentalis) in a protected area in northwest Peru

Estimates of density and population size are fundamental in assessing population trends and ultimately in informing conservation management. Although the abundance of raptors is often expressed as indices of relative abundance, these can be poor correlates of absolute density. In 2008–2009, I calculated the absolute density and population size of Gray‐backed Hawks (Pseudastur occidentalis), an endangered species and Tumbesian endemic, using line transect counts in four different habitat types in a protected area in northwestern Peru. The absolute density of Gray‐backed Hawks in northwest Peru was estimated to be 0.65 individuals km^?2, and the most suitable habitat for the species was located in the provinces of Manabí, Guayas, and Santa Elena in Ecuador, and Tumbes and Piura departments in Peru. The population of Gray‐backed Hawks in my study areas in Tumbes was estimated to be 136, with 94% occurring in dry deciduous and deciduous forest. Because ～60% of all detections in my study were made outside strictly protected areas, including the recently created Angostura‐Faical Regional Conservation Area, conservation of the remaining, non‐protected forests patches in Peru and Ecuador should be a high priority. The current global population of Gray‐backed Hawks has been estimated to be between 250 and 999 birds and declining due to ongoing habitat destruction and fragmentation. Small populations in small habitat fragments, like those in my study area, have high conservation potential, provided that populations are not isolated, and hence should be the focus of constant monitoring.     

Densities and population sizes of raptors in Uganda’s conservation areas

Projected increases in Africa's human population over the next 40 years point to further, large-scale conversion of natural habitats into farmland, with far-reaching consequences for raptor species, some of which are now largely restricted to protected areas (PAs). To assess the importance of PAs for raptors in Uganda, we conducted an annual road survey through savanna, pastoral and agricultural land during 2008–2015. Here, we present density estimates for 34 diurnal raptor species, 17 of which were encountered largely or entirely within PAs. These included seven out of eight globally threatened or near-threatened species surveyed. Based mainly on published demographic values, we converted density estimates (birds 100 km?2) to numbers of adult pairs, for 10 resident, savanna-dependent species. We then estimated adult population sizes within conservation areas (individual PAs and clusters of contiguous PAs), based on the area of savanna in each site. This suggested that two threatened residents, Martial Eagle Polemaetus bellicosus and Lappet-faced Vulture Torgos tracheliotos, have national breeding populations of just 53–75 and 74–105 pairs, respectively. A third species, White-headed Vulture Trigonoceps occipitalis, may have a breeding population of just 22–32 pairs. In each case, at least 90% of pairs are thought to reside within Uganda's five largest conservation areas. In three cases our estimates of pair density were markedly lower than in other studies, while in six cases they were broadly consistent with published findings, often derived using more intensive survey methods. Further work is required to determine the accuracy of our estimates for individual conservation areas, and to assess the long-term viability of Uganda's threatened raptor populations.     

Prey preferences of the cheetah (Acinonyx jubatus) (Felidae: Carnivora): morphological limitations or the need to capture rapidly consumable prey before kleptoparasites arrive?

As a charismatic carnivore that is vulnerable to extinction, many studies have been conducted on predation by the cheetah Acinonyx jubatus . Cheetah are generally considered to capture medium-sized prey; however, which species are actually preferred and why has yet to be addressed. We used data from 21 published and two unpublished studies from six countries throughout the distribution of the cheetah to determine which prey species were preferred and which were avoided using Jacobs' index. The mean Jacobs' index value for each prey species was used as the dependent variable in multiple regression, with prey abundance and prey body mass as predictive variables. Cheetah prefer to kill and actually kill the most available prey present at a site within a body mass range of 23–56 kg with a peak (mode) at 36 kg. Blesbok, impala, Thomson's and Grant's gazelles, and springbok are significantly preferred, whereas prey outside this range are generally avoided. The morphological adaptations of the cheetah appear to have evolved to capture medium-sized prey that can be subdued with minimal risk of injury. Coincidentally, these species can be consumed rapidly before kleptoparasites arrive. These results are discussed through the premise of optimality theory whereby decisions made by the predator maximize the net energetic benefits of foraging. Information is also presented that allows conservation managers to determine which prey species should be in adequate numbers at cheetah reintroduction sites to support a cheetah population. Conversely, these results will illustrate which potential prey species of local conservation concern should be monitored for impact from cheetahs as several species are likely to be preyed upon more frequently than others.     

Wildcat population density in NE Portugal: A regional stronghold for a nationally threatened felid

Population density data on depleted and endangered wildlife species are essential to assure their effective management and, ultimately, conservation. The European wildcat is an elusive and threatened species inhabiting the Iberian Peninsula, with fragmented populations and living in low densities. We fitted spatial capture–recapture models on camera-trap data, to provide the first estimate of wildcat density for Portugal and assess the most influential drivers determining it. The study was implemented in Montesinho Natural Park (NE Portugal), where we identified nine individuals, over a total effort of 3,477 trap-nights. The mean density estimate was 0.032 ± 0.012 wildcat/km², and density tended to increase with distance to humanized areas, often linked to lower human disturbance and domestic cat presence, with forest and herbaceous vegetation cover and with European rabbit abundance. Although, this density estimate is within the range of values estimated for protected areas elsewhere in the Iberian Peninsula, our estimates are low at the European level. When put in context, our results highlight that European wildcats may be living in low population densities across the Iberian Mediterranean biogeographic region. No phenotypic domestic or hybrid cats were detected, suggesting potentially low admixture rates between the two species, although genetic sampling would be required to corroborate this assertion. We provide evidence that Montesinho Natural Park may be a suitable area to host a healthy wildcat population, and thus be an important protected area in this species' conservation context.     

Carnivore conservation under land use change: the status of Zimbabwe’s cheetah population after land reform

Large terrestrial carnivores especially have experienced substantial declines in range and numbers. Changes in land use are a main driver of such declines, yet various developing countries have accelerated land use change through state-led land reform programmes. One of the most renowned land reform programmes is Zimbabwe’s fast track land reform programme (FTLRP), which resulted in fast and compulsory subdivision of large commercial farms into indigenized small scale commercial and subsistence farms. Several case studies have shown an impact of the FTLRP on wildlife, however, its effect on wildlife populations at a nationwide scale remains largely unknown. Due to its wide-ranging nature, the cheetah (Acinonyx jubatus) is particularly vulnerable to changes in land use. In this study I used questionnaire survey and citizen science data to determine the population status and distribution of the cheetah 15 years after introduction of the FTLRP. I also assessed the level of human-cheetah conflict, and attitudes of commercial and subsistence farmers towards cheetah. I found dramatic range contractions and population declines, particularly in the landscape outside protected areas. Despite minimal conflict, subsistence farmers were less tolerant to cheetah than commercial farmers. Consequently, land reform is likely to have increased the hostility of the cheetah landscape outside protected areas. This study is one of the most comprehensive species assessments to date. It provides valuable empirical data on the implications of land use change and emphasizes how a lack of knowledge impedes our ability to recognize a species vulnerability to (local) extinction risk.     

What works for threatened species recovery? An empirical evaluation for Australia

Despite the growing numbers of threatened species and high levels of spending on their recovery worldwide, there is surprisingly little evidence about which conservation approaches are effective in arresting or reversing threatened species declines. Using two government data sets, we examined associations between population trends for 841 nationally-threatened terrestrial species in Australia, and four measures of conservation effort: (a) how much their distribution overlaps with strictly protected areas (IUCN I–IV), (b) and other protected areas (IUCN V–VI), (c) the number of recovery activities directed at the species, and (d) numbers of natural resource conservation activities applied in areas where populations of the threatened species occur. We found that all populations of 606 (72%) species were in decline. Species with greater distributional overlap with strictly protected areas had proportionately more populations that were increasing or stable. This effect was robust to geographic range size, data quality differences and extent of protection. Measures other than strictly protected areas showed no positive associations with stable or increasing trends. Indeed, species from regions with more natural resource conservation activities were found to be more likely to be declining, consistent with differential targeting of such generalised conservation activities to highly disturbed landscapes. Major differences in trends were also found among the different jurisdictions in which species predominantly occurred, which may be related to different legislative protections against habitat destruction. Although we were not able to test causation, this research corroborates other evidence that protected areas contribute to the stabilization or recovery of threatened species, and provides little empirical support for other conservation approaches.     

The critically endangered Asiatic cheetah <Emphasis Type="Italic">Acinonyx jubatus venaticus</Emphasis> in Iran: a review of recent distribution,and conservation status

Considerable effort has been put into conservation of the critically endangered Asiatic cheetah Acinonyx jubatus venaticus in Iran during the past few decades, and a thorough review of the species’ status, demography, range and conservation is provided here. We collated a large dataset of all verified occurrence data, photographic records and mortality cases since 1980 throughout the species’ range in Iran. Currently, the cheetah is distributed throughout the arid landscapes of the eastern half of Iran, but the limits of its current and past range as well as population trends are uncertain. Surveys of nearly 40 different areas resulted in 18 localities with confirmed presence of cheetahs in recent years. Camera trapping has been an effective tool to provide evidence of presence and status of cheetahs, revealing the species’ extremely low density and long inter-reserve movements. Together with photographic records, a total of 82 different cheetahs were detected during the 2000s in Iran. Protection status in most areas has been elevated by the Iran government. Asiatic cheetahs are highly vulnerable to extinction, mainly due to causalities mediated by herder persecution, poaching and road collisions as well as prey and habitat loss. Some efforts have been made to address these threats, but range expansion in recent years is a result of greater survey effort, rather than population recovery. We suggest that, despite conservation investment of the last 15 years, the species remains critically endangered on the verge of extinction.     

Does designation of protected areas ensure conservation of tree diversity in the Sudanian dry forest of Burkina Faso?

The importance of conservation status of the forest (protected versus unprotected) at two sites with differing human population density (high versus low) on the tree diversity of a Sudanian dry forest in Burkina Faso was studied. All woody species were recorded in 127 circular plots (area = 456.16 m²), and density, dominance, frequency, importance value indices and a variety of diversity measures were calculated to assess the species composition, structure and heterogeneity. A total of 69 species, representing 26 families and 52 genera, were found. Combretaceae, Leguminosae subfamily Caesalpinioideae and Rubiaceae were the dominant families. Neither human pressure nor forest conservation status significantly influenced the tree species richness. Stem density and basal area were significantly higher at the site with high population density than otherwise. Fisher’s diversity index revealed the unprotected forest at the site with low population density as the most diverse. We identified species with high conservation importance that should be enriched to maintain a viable population size. In conclusion, the current designation of protected areas seems inefficient at ensuring the conservation of tree diversity in the forest reserve. Thus, participatory conservation programme should be initiated.     

Effectiveness of a protected areas network in the conservation of Tamarindus indica (Leguminosea–Caesalpinioideae) in Benin

In the absence of effective conservation of its wild relatives, exploitation of a species could lead to genetic depletion. Research on how well do protected areas contribute to the conservation of plant species subject to human exploitation is still limited. The potential niche of Tamarindus indica (tamarind) was evaluated and the contribution of the protected areas network (PAN) of Benin to its conservation was assessed. The maximum entropy approach was used to model the ecological niche of the species, and forest inventories were used to address its population structure. To test its effectiveness, the PAN map was overlapped with the habitat suitability map of the species, and its population structures in protected versus unprotected areas were compared. Tamarindus natural populations were confined to the Sudanian and Sudano‐Guinean regions. The species populations in the Sudanian region appeared well represented in protected areas in contrast to those in the Sudano‐Guinean region. Results showed a positive effect of protected areas on juvenile density but a weak effect on adult density and current size‐class distribution. Protection seemed to be unlikely to ensure the long‐term persistence of the species. Cryopreservation, assisted recruitment and artificial enrichment of tamarind stands are recommended to ensure the long‐term persistence of the species.     

Conservation Assessment of Guaiacum sanctum and Guaiacum coulteri: Historic Distribution and Future Trends in Mexico

Guaiacum sanctum and Guaiacum coulteri are long‐lived Mesoamerican timber tree species heavily exploited throughout their range and considered to be at risk of extinction. Both species are included on the IUCN Red List and on CITES Appendix II, but there has been no formal assessment of the conservation status of either species. We used ecological niche modeling and rapid assessments of local density and population size structure to provide such evaluations. For the year 2000, we estimated geographic range sizes for G. sanctum and G. coulteri of 95,422 and 130,973 km², respectively. The main core remaining habitat for G. sanctum occurs in Campeche State (Yucatan Peninsula), where populations exhibit high adult abundance and profuse regeneration. Several areas along the Mexican Pacific coast remain with suitable habitat for G. coulteri. Guaiacum coulteri is at greater risk as only 1.3 percent of its current habitat is protected, which contrasts with the 13.2 percent of current habitat protected for G. sanctum. We projected that available habitat for G. sanctum and G. coulteri will decline by a further 30–50 percent by 2020 if estimated habitat loss rates continue. We suggest that under the IUCN criteria, the conservation status of G. sanctum and G. coulteri should be updated to near threatened and vulnerable, respectively. Additionally, we conclude that the amount of protected habitat needs to be increased to safeguard both species. Our study provides a quantitative basis for updating the conservation status of both species and illustrates an assessment framework that could be applied to other threatened tree species.     

Methods for lion monitoring: a comparison from the Selous Game Reserve,Tanzania

The Selous Game Reserve in Tanzania is believed to contain Africa's largest population of lions (Panthera leo), making it a popular destination for trophy hunters and photographic tourists. However, a lack of recent data has raised concerns about the conservation status of this iconic population, so we collected two types of population data between 2006 and 2009. First, we identified 112 individual animals in an 800 km² study area in the photographic tourism part of Selous, giving a density of 0.14 individuals km^?2. This density estimate was similar to results using the same method from 1997 to 1999, but the adult sex ratio has decreased from 1 male : 1.3 female in 1997 to 1 male : 3 females in 2009. Second, using buffalo calf distress calls, we conducted call‐up surveys to census lions in three hunting sectors in the west, east and south of Selous and in the northern photographic area. Estimated adult lion densities varied from 0.02 to 0.10 km^?2, allowing an overall population estimate of 4,300 (range: 1,700–6,900). Our results highlight the value of call‐ups in surveying cryptic hunted carnivores but stress the importance of long‐term projects for calibrating the responses to call‐ups and for measuring trends in demography and population size.     

Giant Anteater Population Density Estimation and Viability Analysis Through Motion-Sensitive Camera Records

Giant anteater (Myrmecophaga tridactyla) populations are decreasing throughout their range. We tested a methodology for individual identification using camera records and fur patterns to estimate the giant anteater population in a protected area of the Brazilian Cerrado. We identified 9 adult individuals and successfully modeled population abundance and density. Our models estimated an adult population of 16.8 (range = 15–19) giant anteaters through a mark-resight approach and 12.5 individuals (range = 9.7–25.5) through a spatially explicit capture-recapture approach. Density estimates were 0.3–0.4 animals/km². Using these estimates, we performed a population viability analysis to understand and predict this population's future. We modeled scenarios without direct effects and models simulating a double carrying capacity and the supplementation and removal of individuals. Even in the more optimistic scenarios, the population is predicted to decreases over time, with ≤8 individuals remaining in 100 years. Given the study area surroundings, realistic models include removals of giant anteaters in the population. Identification of giant anteaters using cameras can inspire conservationists to acquire population data throughout its distribution and obtain population trends to evaluate the species' conservation status. Individual identification of giant anteaters using a motion-sensitive camera design is feasible, opens new avenues for population analyses, and allows the study of population trends in difficult regions. © 2021 The Wildlife Society.     

Protected species outside the protected areas: People's attitude,threats and conservation of the Yellow Monitor (Varanus flavescens) in the Far-western Lowlands of Nepal

Although there is high potential for conservation of species outside protected areas, it is often neglected in researches and conservation programs. Protected species are legally protected even outside the protected areas and can be flagships for conservation in these areas, but their conservation aspects in these areas are poorly studied. We studied conservation aspects of a poorly known species, Yellow Monitor (Varanus flavescens), which is protected in most of its range countries, outside the protected areas in the Far-western lowlands of Nepal. We studied people's relationship, attitudes and threats to the species through questionnaire survey with adults and children in Parasan Village Development Committee of Kanchanpur District. We found that most of the adults were unaware about the protected status and importance of the species, and both adults as well as children killed the species. The study revealed that most of the killing occurred in agricultural land and children were more responsible for the killing than the adults. We found that monsoon vacation in schools increased the threat to the species. Our study revealed that fear from the species was the main reason and use of the species as food, medicine and hide were other reasons for killing of the species by adults. Low awareness was the major reason behind the killing by children as most of the killing was not related to any good reasons. We estimated that 87 individuals of the species could have been killed in the area in that year. Based on available evidences, we recommend further studies to predict the vulnerability of the species. Our study suggests that raising awareness among locals about its legal status and importance is the simple and efficient measure for the conservation of the species as well as for conserving other protected species outside the protected areas.     

Density estimation and survey validation for swift fox <Emphasis Type="Italic">Vulpes velox</Emphasis> in Oklahoma

The swift fox Vulpes velox Say, 1823, a small canid native to shortgrass prairie ecosystems of North America, has been the subject of enhanced conservation and research interest because of restricted distribution and low densities. Previous studies have described distributions of the species in the southern Great Plains, but data on density are required to evaluate indices of relative abundance and monitor population trends. We examined regressions of swift fox density (estimated by mark-recapture) on timed-track surveys, scat surveys, and catch-per-unit effort indices. Seventy-nine swift foxes (42 male, 37 female) were captured 151 times during 10 240 trapnights between May 2003 and December 2004 in the Panhandle of Oklahoma, USA. Density estimates, based on mark-recapture data from autumn 2004, were 0.08–0.44 foxes/km². Survey indices explained 51 to 76% of the variation in estimates of fox density. Our study indicates that surveys of time-to-track encounters and scat deposition rates show promise in monitoring trends in population abundance over large areas.     

Challenges and opportunities in population monitoring of cheetahs

Population monitoring is key to wildlife conservation and management but is challenging at the spatial and temporal extents necessary for understanding changes. Noninvasive survey methods and spatial capture–recapture (SCR) models have revolutionized wildlife monitoring by providing the means to acquire data at large scales and the framework to generate spatially explicit predictions, respectively. Despite opportunities for improved monitoring, challenges can remain in the study design and model fitting phases of an SCR approach. Here, we used a search-encounter design with multi-session SCR models to collect spatially indexed photographs and estimate changes in density of cheetahs between 2005 and 2013–2016 in the Masai Mara National Reserve (MMNR) in Kenya. Our SCR models of cheetah encounters suggested little change in cheetah density from 2005 to 2013–2016, with some evidence that density fluctuated annually in the MMNR. The sampling period length (5 vs. 10 months) and timing (early, late, full year) over which spatial encounters were modeled did not alter inferences about density when sample sizes were adequate (>20 spatially distinct encounters). Our average density estimate of ~1.2 cheetahs/100 km² is consistent with the impression that the MMNR provides important cheetah habitat in Africa. During most years, spatial distribution of vegetation greenness (proxy for ungulate habitat quality) accounted for important variation in encounter rates. The search-encounter design here could be applied to other regions for cheetah monitoring. While snapshot estimates of population size across time are useful for wildlife monitoring, open population models may better identify the mechanisms behind temporal changes.     

Dietary preference of cheetahs (Acinonyx jubatus) in south‐eastern Kenya

The conversion of natural ecosystems due to anthropogenic activities has led to the destruction of natural habitats and to the deterioration of habitat quality. Top predators particularly respond sensitively to changes in habitat structures, including the availability of prey. The cheetah Acinonyx jubatus prefers small‐medium‐sized, wild ungulate prey due to the cheetah''s morphological adaptations. However, the majority of the species’ population is found beyond protected areas, where habitat structures, species abundances, and community composition are highly influenced by human activities. Only few studies have analyzed the diet preference of cheetahs in relation to prey availability and abundance for rangelands beyond protected areas in Eastern Africa. The study aimed to determine cheetah prey preference in the rangelands of south‐eastern Kenya based on scat analyses. We compared dietary preference of cheetah with prey availability. For this purpose, we conducted standardized game counts. We analyzed 27 cheetah scat samples collected across the same study area where we also conducted game counts. We found that Grant''s gazelle Gazella granti contributed the highest portion of cheetah''s diet, although Thomson''s gazelle Gazella thomsonii was the most abundant medium‐sized ungulate prey in the study areas. We also recorded two primate species, yellow baboon Papio cynocephalus and vervet monkey Chlorocebus pygerythrus, as well as the rock hyrax Procavia capensis in the cheetah diet. These species have never been documented as cheetah prey before. Furthermore, our results document livestock as potential prey for cheetahs. These observations underline that cheetah use diverse prey in rangelands outside protected areas, and that the abundance of specific prey does not influence cheetah prey preference.     

Living on the edge: Multiscale habitat selection by cheetahs in a human‐wildlife landscape

Animals select habitats that will ultimately optimize their fitness through access to favorable resources, such as food, mates, and breeding sites. However, access to these resources may be limited by bottom‐up effects, such as availability, and top‐down effects, such as risk avoidance and competition, including that with humans. Competition between wildlife and people over resources, specifically over space, has played a significant role in the worldwide decrease in large carnivores. The goal of this study was to determine the habitat selection of cheetahs (Acinonyx jubatus) in a human‐wildlife landscape at multiple spatial scales. Cheetahs are a wide‐ranging, large carnivore, whose significant decline is largely attributed to habitat loss and fragmentation. It is believed that 77% of the global cheetah population ranges outside protected areas, yet little is known about cheetahs’ resource use in areas where they co‐occur with people. The selection, or avoidance, of three anthropogenic variables (human footprint density, distance to main roads and wildlife areas) and five environmental variables (open habitat, semiclosed habitat, edge density, patch density and slope), at multiple spatial scales, was determined by analyzing collar data from six cheetahs. Cheetahs selected variables at different scales; anthropogenic variables were selected at broader scales (720–1440 m) than environmental variables (90–180 m), suggesting that anthropogenic pressures affect habitat selection at a home‐range level, whilst environmental variables influence site‐level habitat selection. Cheetah presence was best explained by human presence, wildlife areas, semiclosed habitat, edge density and slope. Cheetahs showed avoidance for humans and steep slopes and selected for wildlife areas and areas with high proportions of semiclosed habitat and edge density. Understanding a species’ resource requirements, and how these might be affected by humans, is crucial for conservation. Using a multiscale approach, we provide new insights into the habitat selection of a large carnivore living in a human‐wildlife landscape.     

Boots on the ground: in defense of low-tech,inexpensive, and robust survey methods for Africa’s under-funded protected areas

Protected area managers need reliable information to detect spatial and temporal trends of the species they intend to protect. This information is crucial for population monitoring, understanding ecological processes, and evaluating the effectiveness of management and conservation policies. In under-funded protected areas, managers often prioritize ungulates and carnivores for monitoring given their socio-economic value and sensitivity to human disturbance. Aircraft-based surveys are typically utilized for monitoring ungulates because they can cover large areas regardless of the terrain, but such work is expensive and subject to bias. Recently, unmanned aerial vehicles have shown great promise for ungulate monitoring, but these technologies are not yet widely available and are subject to many of the same analytical challenges associated with traditional aircraft-based surveys. Here, we explore use of inexpensive and robust distance sampling methods in Kafue National Park (KNP) (22,400 km²), carried out by government-employed game scouts. Ground-based surveys spanning 101, 5-km transects resulted in 369 ungulate group detections from 20 species. Using generalized linear models and distance sampling, we determined the environmental and anthropogenic variables influencing ungulate species richness, density, and distribution. Species richness was positively associated with permanent water and percent cover of closed woodland vegetation. Distance to permanent water had the strongest overall effect on ungulate densities, but the magnitude and direction of this effect varied by species. This ground-based approach provided a more cost-effective, unbiased, and repeatable method than aerial surveys in KNP, and could be widely implemented by local personnel across under-funded protected areas in Africa.     

Heterogeneity in the density of spotted hyaenas in Hluhluwe-iMfolozi Park,South Africa

Animal population sizes and trends, as well as their distributions, are essential information to the understanding and conservation of ecosystems. During this study in Hluhluwe-iMfolozi Park, South Africa, a spotted hyaena Crocuta crocuta Erxleben, 1777 (Hyaenidae) population was surveyed by attracting individuals with pre-recorded sounds. The hyaena population (excluding cubs) is substantially larger (321 individuals) than the previous estimate of 200 and this population is the second largest protected population in South Africa. Average hyaena density, at 0.357 individuals/km², was relatively high compared to other southern African conservation areas, and range from 0 to 1.25 individuals/km² across sampling stations. For short periods, spatial heterogeneity in density was marked at small and large spatial scales, but decreased when averaged over a longer period. This heterogeneity may be important in promoting the coexistence of other large and mobile carnivores in Hluhluwe-iMfolozi Park by creating potential dynamic competition refugia in space and time. Furthermore, heterogeneity of hyaena density at smaller scales should influence studies investigating the avoidance of hyaenas by competitively inferior carnivores.     

Vegetation change in acidic dry grasslands in Moravia (Czech Republic) over three decades: Slow decrease in habitat quality after grazing cessation

Aims

Shallow soils on acidic bedrock in dry areas of Central Europe support dry grasslands and heathlands that were formerly used as extensive pastures. These habitats are of high conservation value, but their abandonment in the 20th century triggered slow natural succession that poses a threat to specialized plant species. We asked how this vegetation and its plant diversity have changed over the past three decades and whether protected areas have positively affected habitat quality.

Location

Southwestern and central Moravia, Czech Republic.

Methods

In 2018–2019, we resurveyed 94 vegetation plots first sampled in 1986–1991 at 47 acidic dry grassland and heathland sites. We compared the number of all vascular plant species, Red List species and alien species per plot using parametric and non-parametric tests, life-form spectra using the chi-square test, species composition using detrended correspondence analysis, and indicator values using a permutation test. We also compared these changes between sites within and outside protected areas.

Results

Vegetation changes over the past three decades have been relatively small. However, we detected a decrease in total species richness, the number of Red List species and the number of characteristic species of dry grasslands. Neophytes were infrequent, while archaeophytes increased slightly. The competitive tall grass Arrhenatherum elatius, annual species and young woody plants increased in abundance or newly established at many sites. Indicator values did not change except for a slight increase in nutrient values. These negative trends occurred both within and outside protected areas but were more pronounced outside.

Conclusions

Formerly grazed acidic dry grasslands and heathlands in Moravia are slowly losing habitat specialists, including threatened plant species, and are increasingly dominated by Arrhenatherum elatius. Conservation management, especially cutting in protected areas, slows down the negative trends of decline in plant diversity and habitat quality but is insufficient to halt these processes completely.