Semiaquatic organisms depend on the features of both water bodies and landscapes; the interplay between terrestrial and aquatic systems might influence the semiaquatic communities, determining the scale at which management would be more effective. However, the consequences of such interplay are not frequently quantified, particularly at the community level. We analyzed the distribution of amphibians to evaluate whether the influence of landscape features on freshwater ecosystems can have indirect consequences at both the species and community level. We surveyed 74 streams in northern Italy to obtain data on breeding amphibians, water, and microhabitat features; we also measured features of surrounding landscapes. We used an information-theoretic approach and structural equation models to compare hypotheses on causal relationships between species distribution and variables measured at multiple levels. We also used a constrained redundancy analyses to evaluate causal relationships between multivariate descriptors of habitat features and community composition. Distribution of Salamandra salamandra was related to landscape, hydrological, and water characteristics: salamanders were more frequent in permanent streams with low phosphate concentration within natural landscapes. Water characteristics were dependent on landscape: streams in natural landscapes had less phosphates. Landscape influenced the salamander both directly and indirectly through its influence on phosphates. Community structure was determined by both landscape and water characteristics. Several species were associated with natural landscapes, and with particular water characteristics. Landscape explained a significant proportion of variability of water characteristics; therefore it probably had indirect effects on community. Upland environments play key roles for amphibians, for example, as the habitat of adults, but upland environments also have indirect effects on the aquatic life stages, mediated through their influence on water characteristics. Synergistic effects can magnify the negative consequences of landscape alteration on amphibians; landscape management can be particularly effective, as it can also improve wetland features.
Different semi-natural habitats occur on farmland, and it is the vegetation's traits and structure that subsequently determine their ability to support natural enemies and their associated contribution to conservation biocontrol. New habitats can be created and existing ones improved with agri-environment scheme funding in all EU member states. Understanding the contribution of each habitat type can aid the development of conservation control strategies. Here we review the extent to which the predominant habitat types in Europe support natural enemies, whether this results in enhanced natural enemy densities in the adjacent crop and whether this leads to reduced pest densities. Considerable variation exists in the available information for the different habitat types and trophic levels. Natural enemies within each habitat were the most studied, with less information on whether they were enhanced in adjacent fields, while their impact on pests was rarely investigated. Most information was available for woody and herbaceous linear habitats, yet not for woodland which can be the most common semi-natural habitat in many regions. While the management and design of habitats offer potential to stimulate conservation biocontrol, we also identified knowledge gaps. A better understanding of the relationship between resource availability and arthropod communities across habitat types, the spatiotemporal distribution of resources in the landscape and interactions with other factors that play a role in pest regulation could contribute to an informed management of semi-natural habitats for biocontrol.
Millions of farm ponds have been constructed in agricultural landscapes around the globe. These ponds are built to support a variety of functions, including erosion control, cattle grazing, and recreational fishing, but their role as breeding habitat for amphibians remains poorly understood. We addressed this knowledge gap by studying farm ponds in the eastern Great Plains of the United States, a pond‐dense region dominated by agriculture. We used field surveys and occupancy modeling to identify the important biophysical components of amphibian habitat and to assess the species‐specific effects of cattle and fish presence on breeding occupancy. We next used a chronosequence to determine whether pond renovation, which often occurs when ponds are about 40 yr old, threatens the development of amphibian habitat. Nine amphibian species bred in the farm ponds that we surveyed, and the relationship between breeding occupancy and habitat variables varied by species. We found that the pH conditions associated with amphibian breeding occupancy were significantly more likely to occur in older ponds (>50 yr old). Emergent vegetation cover was also associated with increased breeding probability and rarely reached high levels in newer ponds. Since the older ponds with suitable habitat are at an age where renovation is likely needed to restore their agricultural function, this habitat may be at risk. We suggest that conservation of amphibians in farm ponds in the United States will require adopting renovation and management practices that balance the multiple uses of these sites and maintain a mosaic of pond successional states.
Southern California is a biodiversity hotspot, an area with high species richness and where many species are threatened with extinction. Six lepidopteran taxa are of conservation concern, including three listed on the United States Endangered Species Act. The Harbison's dun skipper (Euphyes vestris harbisoni) may also have an elevated risk of extinction; however, little is known about its ecology or current status. Due to this conservation concern, we conducted surveys for the skipper to more fully describe its distribution, assess the interannual variation in adult population sizes, and further describe its natural history and habitat requirements (including threats). The known distribution now includes western Riverside County and northern Baja California, Mexico, with the historically reported Orange and San Diego counties. We were able to document 33 historic and/or current skipper locations on public lands and another six historic records on inaccessible private lands. Just over half of the 39 locations were extant populations, about a quarter have been extirpated, with the remainder of unknown status. For extant populations, population sizes appear to be relatively small. We also provide information on efficient monitoring protocols for the skipper. The information obtained from this study is necessary to make data-driven management decisions so that conservation efforts can be effective and efficient.
Habitat conservation is performed in North America to support populations of managed and wild pollinators. The current recommended plant selections for northeastern pollinator habitats primarily provide resources for common or generalist pollinators. However, such plants may not benefit uncommon or rare northeastern specialist pollinators, whose populations are susceptible to harm from anthropogenic threats. This manuscript presents the first catalog of native specialist bees and associated host plants for the Northeast. Approximately 15% of northeastern native bee species are pollen specialists, represented by 6 families, 15 genera, and 61 species of bees that restrict pollen foraging to 23 families, 33 genera, and 201 possible species of native host plants. Specialist bees are associated with non-graminoid forbs and non-coniferous woody plants in nearly all major northeastern terrestrial and wetland habitats. Herein, I identify and discuss vulnerable bee–plant associations and suggest greater emphasis on research and restoration efforts. I recommend that northeastern pollinator-conservation practice specifically target specialist bees.
Francois' langur (Trachypithecus francoisi) is an endangered primate and endemic to the limestone forests of the tropical and subtropical zone of northern Vietnam and South-west China with a population of about 2,000 individuals. Conservation efforts are hampered by limited knowledge of habitat preference in its main distribution area. We surveyed the distribution of Francois' langur and modeled the relationship between the probability of use and habitat features in Mayanghe National Nature Reserve, Guizhou, China. The main objectives of this study were to provide quantitative information on habitat preference, estimating the availability of suitable habitat, and providing management guidelines for the effective conservation of this species. By comparing 92 used locations with habitat available in the reserve, we found that Francois' langur was mainly distributed along valleys and proportionally, used bamboo forests and mixed conifer-broadleaf forests more than their availability, whereas they tended to avoid shrubby areas and coniferous forests. The langur tended to occur at sites with lower elevation, steeper slope, higher tree canopy density, and a close distance to roads and water. The habitat occupancy probability was best modeled by vegetation type, vegetation coverage, elevation, slope degree, distances to nearest water, paved road, and farmland edge. The suitable habitat in this reserve concentrated in valleys and accounted for about 25% of the total reserve area. Our results showed that Francois' langur was not only restricted at the landscapes level at the regions with karst topography, limestone cliffs, and caves, but it also showed habitat preference at the local scale. Therefore, the protection and restoration of the langur preferred habitats such as mixed conifer-broadleaf forests are important and urgent for the conservation of this declining species.
Many species of conservation concern are habitat limited and often a major focus of management for these species is habitat acquisition and/or restoration. Deciding the location of habitat restoration or acquisition to best benefit a protected species can be a complicated subject with competing management objectives, ecological uncertainties and stochasticity. Structured decision making (SDM) could be a useful approach for explicitly incorporating those complexities while still working toward species conservation and/or recovery. We applied an SDM approach to Red Hills salamander Phaeognathus hubrichti habitat conservation decision making. Phaeognathus hubrichti is a severely range‐limited endemic species in south central Alabama and has highly specific habitat requirements. Many known populations live on private lands and the primary mode of habitat protection is habitat conservation planning, but such plans are non‐binding and not permanent. Working with stakeholders, we developed an objectives hierarchy linking land acquisition or protection actions to fundamental objectives. We built a model to assess and compare the quality of the habitat in the known range of P. hubrichti. Our model evaluated key habitat attributes of 5814 pixels of 1 km2 each and ranked the pixels from best to worst with respect to P. hubrichti habitat requirements. Our results are a spatially explicit valuation of each pixel, with respect to its probable benefit to P. hubrichti populations. The results of this effort will be used to rank pixels from most to least beneficial, then identify land owners in the most useful areas for salamanders who are willing to sell or enter into a permanent easement agreement. Deciding the location of habitat restoration or acquisition to best benefit a protected species can be complicated, having competing management objectives, ecological uncertainties, and stochasticity. We applied a structured decision making approach to Red Hills salamander Phaeognathus hubrichti habitat conservation decision making. Working with stakeholders, we developed an objectives hierarchy linking land acquisition or protection actions to species conservation and management cost fundamental objectives. We built a model to assess and compare the quality of the habitat in the known range of P. hubrichti. The results of this effort will be used to rank potential habitat from most to least beneficial then identify land owners in the most useful areas for salamanders who are willing to sell or enter into a permanent easement agreement.
Effective marine habitat protection requires life history information, including identification of connected adult habitats and spawning sites, and movement information throughout those areas. Here, we implemented a mark-recapture study in the Bahamas Archipelago to estimate patterns of site fidelity, and to determine what homesites are connected to pre-spawning sites of economically important Bonefish (Albula vulpes) across multiple islands. We captured over 7000 Bonefish via seine netting, marked them with dart tags, and relied on fishing guides and anglers to report recaptures on Abaco, Grand Bahama, and Andros. Mark-recapture results from the three islands showed that 60–80% of Bonefish were recaptured within 5 km of their tagging site. Across the three islands, mean distance between mark and recapture was less than 11 km, suggesting space use that is tractable for effective marine reserve implementation. We also found that pre-spawning sites housed individuals from multiple homesites that were separated by distances up to 75 km. With these connections in mind, conserving Bonefish spawning biomass necessitates habitat protection in multiple home areas, along migratory corridors, and at pre-spawn and spawning locations. Our case study illustrates how mark-recapture of a C&R species can be used to identify habitats for protection. Information from this mark-recapture study contributed to the designation of six National Parks aimed at protecting habitats used by Bonefish, as well as other spatially overlapping species.
Recovery of large carnivores in the European human‐dominated landscapes has sparked a debate regarding the optimal landscape conditions in which carnivores can thrive and coexist with humans. Here, we use brown bears Ursus arctos in the Romanian Carpathians to test and develop a framework for identifying habitat conservation priorities based on a novel integration of resource selection functions, home‐range data and systematic conservation planning. We used a comprehensive GPS telemetry dataset from 18 individuals to (1) calculate sex‐specific seasonal home ranges and (2) characterize population‐level habitat selection. We then used systematic conservation planning software Zonation to identify contiguous areas of high conservation value for males and females using Manly's habitat selection ratios as weights for habitat layers, and home‐range information as a smoothing parameter for habitat connectivity. Home ranges were smallest during winter (median [IQR] for November–February: 28.2 km2 [9.8–42.4]), and largest during the intense‐feeding season (September–November: 127.3 km2 [62.2–288.5]), with males having larger home ranges across all seasons. Females consistently selected for mixed forest habitat during all seasons. Males selected mixed forest during winter; then switched to a rather generalist approach, selecting regenerating forest and mixed and coniferous forests during low‐feeding/reproduction and wild berries seasons. We identified large tracts of forest habitat (~14% of the landscape) that was selected across all seasons as key habitats for brown bear conservation in the Romanian Carpathians. Spatially, high‐value winter habitat was the most dissimilar for both males and females, suggesting that conservation actions should focus on protecting contiguous denning habitat. These key findings can inform the management and conservation of the brown bear population in the Romanian Carpathians by identifying critical intervention areas for maintaining landscape connectivity, enable transboundary management and contribute to maintaining Favourable Conservation Status, an important target of European Union Strategy for Biodiversity. Recovery of large carnivores in the European human‐dominated landscapes has sparked a debate regarding the optimal landscape conditions in which carnivores can thrive and coexist with humans. We developed a framework for identifying habitats for conservation, using brown bears in the Eastern Carpathians as a case study, based on a novel integration of resource selection functions, home range data, and systematic conservation planning. We identified large tracts of forest as key habitats for brown bear conservation in the Eastern Carpathians. Spatially, high conservation value winter habitat was the most dissimilar for both males and females, suggesting that conservation actions should focus on protecting denning habitat. These key findings contribute to identifying critical intervention areas for maintaining landscape integrity and connectivity for the focal species.
Divergent habitat utilization and niche partitioning can cause high degrees of ecological specialization even in generalist species. For example, sex‐specific specialization results in differential habitat use, which, if neglected in monitoring studies, can lead to biased estimates of population sizes. However, many widely used methods of population monitoring such as bioacoustical surveys of echolocating bats cannot take such demographic differences into account, due to methodological limitations. Here, we use ecological niche factor analysis (ENFA) to derive habitat suitability maps (HSMs) of male and female parti‐coloured bat Vespertilio murinus using previously published radio‐tracking data. The ENFA revealed that males and females were highly specialized and ecologically segregated. Accordingly, we found that significantly more high‐quality habitats were available for males than for females, with no spatial overlap between sexes. The HSMs allowed us to estimate the skew in the distribution of the sexes in space. Our approach provides a way to estimate intra‐species spatial segregation and consequently generate a more accurate prediction of effective population size and niche requirements of vulnerable species. This study also highlights the importance of making geographic and environmental data, as well as animal occurrence and movement data publicly available for the benefit of conservation efforts.