Find research datasets worth reusing

Data from: Using the Spatial Population Abundance Dynamics Engine for conservation management

1. An explicit spatial understanding of population dynamics is often critical for effective management of wild populations. Sophisticated approaches are available to simulate these dynamics, but are largely either spatially homogeneous or agent-based, and thus best suited to small spatial or temporal scales. These approaches also often ignore financial decisions crucial to choosing management approaches on the basis of cost-effectiveness. 2. We created a user-friendly and flexible modelling framework for simulating these population issues at large spatial scales – the Spatial Population Abundance Dynamics Engine (SPADE). SPADE is based on the STAR model (McMahon et al. 2010) and uses a reaction-diffusion approach to model population trajectories and a cost-benefit analysis technique to calculate optimal management strategies over long periods and across broad spatial scales. It expands on STAR by incorporating species interactions and multiple concurrent management strategies, and by allowing full user control of functional forms and parameters. 3. We used SPADE to simulate the eradication of feral domestic cats Felis catus on sub-Antarctic Marion Island (Bester et al. 2002) and compared modelled outputs to observed data. The parameters of the best-fitting model reflected the conditions of the management programme, and the model successfully simulated the observed movement of the cat population to the southern and eastern portion of the island under hunting pressure. We further demonstrated that none of the management strategies would likely have been successful within a reasonable timeframe if performed in isolation. 4. SPADE is applicable to a wide range of population management problems, and allows easy generation, modification and analysis of management scenarios. It is a useful tool for the planning, evaluation and optimisation of the management of wild populations, and can be used without specialised training.

Data from: Squamate Conserved Loci (SqCL): a unified set of conserved loci for phylogenomics and population genetics of squamate reptiles

The identification of conserved loci across genomes, along with advances in target capture methods and high-throughput sequencing, has helped spur a phylogenomics revolution by enabling researchers to gather large numbers of homologous loci across clades of interest with minimal upfront investment in locus design. Target capture for vertebrate animals is currently dominated by two approaches – anchored hybrid enrichment (AHE) and ultraconserved elements (UCE) – and both approaches have proven useful for addressing questions in phylogenomics, phylogeography, and population genomics. However, these two sets of loci have minimal overlap with each other; moreover, they do not include many traditional loci that that have been used for phylogenetics. Here, we combine across UCE, AHE, and traditional phylogenetic gene locus sets to generate the Squamate Conserved Loci (SqCL) set, a single integrated probe set that can generate high-quality and highly complete data across all three loci types. We use these probes to generate data for 44 phylogenetically-disparate taxa that collectively span approximately 33% of terrestrial vertebrate diversity. Our results generated an average of 4.29 Mb across 4709 loci per individual, of which an average of 2.99 Mb was sequenced to high enough coverage (≥10×) to use for population genetic analyses. We validate the utility of these loci for both phylogenomic and population genomic questions, provide a comparison among these locus sets of their relative usefulness, and suggest areas for future improvement.

Data from: Assessing the conservation value of secondary savanna for large mammals in the Brazilian Cerrado

Debate about the conservation value of secondary habitats has tended to focus on tropical forests, increasingly recognizing the role of secondary forests for biodiversity conservation. However, there remains a lack of information about the conservation value of secondary savannas. Here, we conducted a camera trap survey to assess the effect of secondary vegetation on large mammals in a Brazilian Cerrado protected area, using a single-season occupancy framework to investigate the response of individual species (species-level models) and of all species combined (community-level models). In addition, we investigated the cost effectiveness of different sampling designs to monitor globally threatened species in the study area. At the community level, savanna that regenerated from eucalyptus plantation had similar occupancy estimate as old growth areas. At the species level, none of the ten species individually assessed seemed to respond to succession stage, with greater support for the effect of other covariates on occupancy, such as distance from water and vegetation physiognomy. These results demonstrate that secondary vegetation does not appear to negatively impact large mammals in the study area and suggest that, given a favorable context, Cerrado mammals can recolonize and use secondary savannas that regenerated from clearcut. However, our study area should be considered a best-case scenario, as it retained key ecological attributes of high-value secondary habitats. Our simulations showed that a sampling design with 60 camera trap sites surveyed during nine occasions is appropriate to monitor most globally threatened species in the study area, and could be a useful starting point for new monitoring initiatives in other Cerrado areas.

Data from: Structural diversity of naturally regenerating Chinese yew (Taxus wallichiana var. mairei) populations in an ex situ conservation

The Chinese yew (Taxus wallichiana var. mairei) is ranked among the first class of important wild endangered plants in China. However, due to its overexploitation, it now occurs scattered in the forest undergrowth along the Yangtze River Valley. To improve this tree's conservation management, we used structural indices to investigate the structural diversity of naturally regenerating yew populations that have established via ex situ conservation. The results show that most yews had larger non-yew tree neighbors; these were 30–70% larger than their reference trees. Collectively, the average distances between the yews and the three nearest-neighboring trees were short (<3 m). This result suggests that the yews likely face strong interspecific competition from neighbors. In these two forest stands, most of the pole-sized yews are found beneath a single tall neighboring tree (height ≥10 m), and their growth was enhanced under a single neighboring tree but not under two, three or zero neighboring trees. Finally, we recommend simple silvicultural treatments to reduce interspecific competition; specifically, the cutting or pruning of branches of large neighboring trees in tandem with the thinning of canopy trees growing next to the mother yews.

Data from: Predicting global population connectivity and targeting conservation action for snow leopard across its range

Movements of individuals within and among populations help to maintain genetic variability and population viability. Therefore, understanding landscape connectivity is vital for effective species conservation. The snow leopard is endemic to mountainous areas of Central Asia and occurs within 12 countries. We assess potential connectivity across the species' range to highlight corridors for dispersal and genetic flow between populations, prioritizing research and conservation action for this wide-ranging, endangered top-predator. We used resistant kernel modeling to assess snow leopard population connectivity across its global range. We developed an expert-based resistance surface that predicted cost of movement as functions of topographical complexity and land cover. The distribution of individuals was simulated as a uniform density of points throughout the currently accepted global range. We modeled population connectivity from these source points across the resistance surface using three different dispersal scenarios that likely bracket the lifetime movements of individual snow leopard: 100km, 500km and 1000km. The resistant kernel models produced predictive surfaces of dispersal frequency across the snow leopard range for each distance scenario. We evaluated the pattern of connectivity in each of these scenarios and identified potentially important movement corridors and areas where connectivity might be impeded. The models predicted two regional populations, in the north and south of the species range respectively, and revealed a number of potentially important connecting areas. Discrepancies between model outputs and observations highlight unsurveyed areas of connected habitat that urgently require surveying to improve understanding of the global distribution and ecology of snow leopard, and target land management actions to prevent population isolation. The connectivity maps provide a strong basis for directed research and conservation action, and usefully direct the attention of policy makers.

opencc-zeroNov 2019View details →

Effect of participation in commercial production of medicinal plants through community-based conservation groups on farm income at Kakamega forest, Kenya

<p class="Abstract">Forest conservation by peripheral communities is one of the most advocated strategies for ensuring sustainable supply of forest goods and services. In Kenya, although conservation activities generate considerable environmental improvements, studies evaluating the economic benefits are very limited. This study aimed at assessing the impact of participating in the commercialization training program by forest adjacent communities on farm income. Utilizing matching techniques, the analysis is based on the data collected from a randomly selected sample of farm households around Kakamega forest in Kenya. The results show that age, forest distance, forest benefit, market distance and farming experience are the main factors that influence the participation in the commercialization program. Also, participating in commercial production of medicinal plants has a positive and significant effect on farmers' income. The average treatment effect on the treated (ATT), based on three estimation algorithms, ranges from KSH. 80,047 to KSH. 176,788 per hectare, per year, implying that policy efforts that focus on the participation in the commercialization program of medicinal plants can enhance incomes among farm-dependent households. The findings from this study suggest that upscaling the participation in the commercialization program to other areas.</p>

opencc-zeroDec 2013View details →

Data from: Genetic diversity, demographical history and conservation aspects of the endangered yew tree Taxus contorta (syn. Taxus fuana) in Pakistan

Western Himalayan yew (Taxus contorta Griffith, synonym T. fuana Nan Li & R.R. Mill), one of the highly prized tree species for its anticancer properties is experiencing severe reduction in populations across its range in Pakistan. We examined a chloroplast DNA region (trnL-F) and ten nuclear microsatellite loci variations among seven populations to investigate the levels of genetic diversity and demographical history of T. contorta in Pakistan. Low haplotype diversity (HT = 0.182), moderate level of microsatellite diversity (HE = 0.526 ± 0.034), significant population differentiation (FST = 0.106) and high level of inbreeding (FIS = 0.222-0.418) was found in T. contorta compared with its congeners. Results of mismatch distribution analysis, neutrality tests and data on glacial chronologies of western Himalaya indicated that demographic expansion of T. contorta in Pakistan predates extensive glaciations that occurred during late Pleistocene (140.06 thousand years ago (kya), and the spatial expansion most likely happened very recently in the Holocene (6.71 kya). An unprecedented level of habitat disturbances since past few decades coupled with the severe historic climate may have played an important role on an extant population structure of T. contorta. We have discussed a range of sustainable management measures for the ecological restoration of remnant populations as well as to exploit high economic benefits that can be obtained from this species.

Data from: Testing the prey-trap hypothesis at two wildlife conservancies in Kenya

Protecting an endangered and highly poached species can conflict with providing an open and ecologically connected landscape for coexisting species. In Kenya, about half of the black rhino (Diceros bicornis) live in electrically fenced private conservancies. Purpose-built fence-gaps permit some landscape connectivity for elephant while restricting rhino from escaping. We monitored the usage patterns at these gaps by motion-triggered cameras and found high traffic volumes and predictable patterns of prey movement. The prey-trap hypothesis (PTH) proposes that predators exploit this predictable prey movement. We tested the PTH at two semi-porous reserves using two different methods: a spatial analysis and a temporal analysis. Using spatial analysis, we mapped the location of predation events with GPS and looked for concentration of kill sites near the gaps as well as conducting clustering and hot spot analysis to determine areas of statistically significant predation clustering. Using temporal analysis, we examined the time lapse between the passage of prey and predator and searched for evidence of active prey seeking and/or predator avoidance. We found no support for the PTH and conclude that the design of the fence-gaps is well suited to promoting connectivity in these types of conservancies.

Data from: Multi-objective optimization for plant germplasm collection conservation of genetic resources based on molecular variability

Germplasm collections play a significant role among strategies for conservation of diversity. It is common to select a core collection to represent the genetic diversity of a germplasm collection, in order to minimize the cost of conservation, while ensuring the maximization of genetic variation. We aimed to solve two main problems: (1) to select a set of individuals, from an in situ data set, that is genetically complementary to an existing germplasm collection, and (2) to define a core collection for a germplasm collection. We proposed a new multi-objective optimization (MOO) approach based on principles of systematic conservation planning (SCP) incorporating heterozygosity information; therefore, optimization takes genotypic diversity and variability patterns into account as well. As a case study, we used Dipteryx alata microsatellite loci information from two sources, an ex situ germplasm collection located at the Agronomy School of the Federal University of Goiás (UFG-AS), and an in situ data set composed of 642 sampled individual trees. We were able to identify within a population of several individuals, the exact accessions/samples that should be chosen in order to preserve the species diversity. We found that material from nine in situ individual trees are enough to complement the UFG-AS germplasm collection as it is, and that it is possible to define a core collection of 20 individual trees representing all studied genetic diversity. Moreover, we defined a method (a protocol) to deal with large amounts of accessions in the context of MOO. The proposed approach can be used to help constructing collections with maximal allelic richness and can also be extended to the in situ conservation. As far as we know, this is the first time that principles of SCP and the MOO approach are applied to the problem of complementing a germplasm collection and of finding a core collection for a germplasm collection.

opencc-zeroDec 2012View details →

Data from: Intercolony movement of pre-breeding seabirds over oceanic scales: implications of cryptic age-classes for conservation and metapopulation dynamics

Aim: Demographic linkage between subpopulations plays a critical role in population processes. Metapopulation dynamics, however, remains one of the most poorly understood aspects of population biology. This is especially true for small, pelagic seabirds because their discrete subpopulations are located on offshore islands, separated by vast areas of open ocean, making monitoring logistically challenging. Seabird populations often contain large numbers of immature pre-breeders that may be important for subpopulation connectivity and demography, but are poorly studied. Here we provide evidence for intercolony movement of pre-breeding Leach's storm-petrels Oceanodroma leucorhoa among three colonies spanning the North Atlantic Ocean. We discuss their influence on metapopulation dynamics and the extinction risk of a subpopulation under threat from extreme predation. Location: North Atlantic Ocean Islands (Scotland, Canada & Iceland). Methods: We use a novel application of Bayesian stable isotope mixing models to infer recent movement of pre-breeding birds between three major breeding populations in the North Atlantic. Carbon and nitrogen stable isotope values from breeding birds (central place foragers) sampled at each colony were used as model sources and pre-breeding birds as model mixtures. Results: Of 134 pre-breeding Leach's storm-petrels sampled at three colonies across the North Atlantic, five had isotope mixing model estimates dissimilar (< 25%) to their colony of capture and were instead isotopically similar to another breeding region. Nineteen further pre-breeders had highly mixed signatures (< 50% for the colony of capture), indicating possible recent movement between colonies. Main conclusions: Our findings provide evidence for interpopulation connectivity of pre-breeding Leach's storm-petrels among colonies spanning the North Atlantic. These results highlight the significance of cryptic young age-classes in metapopulation dynamics and the demographic processes. Moreover, they provide us with a better understanding of how one subpopulation remains extant, despite experiencing extreme predation rates.

Data from: Evidence of the phenotypic expression of a lethal recessive allele under inbreeding in a wild population of conservation concern

Deleterious recessive alleles that are masked in outbred populations are predicted to be expressed in small, inbred populations, reducing both individual fitness and population viability. However, there are few definitive examples of phenotypic expression of lethal recessive alleles under inbreeding conditions in wild populations. Studies that demonstrate the action of such alleles, and infer their distribution and dynamics, are required to understand their potential impact on population viability and inform management responses. The Scottish population of red-billed choughs (Pyrrhocorax pyrrhocorax), which currently totals <60 breeding pairs and is of major conservation concern, has recently been affected by lethal blindness in nestlings. We used family data to show that the pattern of occurrence of blindness within and across affected families that produced blind nestlings was exactly 0·25, matching that expected given a single-locus autosomal lethal recessive allele. Furthermore, the observed distribution of blind nestlings within affected families did not differ from that expected given Mendelian inheritance of such an allele. Relatedness estimates showed that individuals from affected families were not more closely related to each other than they were to individuals from unaffected families that did not produce blind nestlings. Blind individuals tended to be less heterozygous than non-blind individuals, as expected if blindness was caused by the expression of a recessive allele under inbreeding. However, there was no difference in the variance in heterozygosity estimates, suggesting that some blind individuals were relatively outbred. These results suggest carriers of the blindness allele may be widely distributed across contemporary families rather than restricted to a single family lineage, implying that the allele has persisted across multiple generations. Blindness occurred at low frequency (affecting 1·6% of observed nestlings since 1981). However, affected families had larger initial brood sizes than unaffected families. Such high fecundity of carriers of a lethal recessive allele might reflect overdominance, potentially reducing purging and increasing allele persistence probability. We thereby demonstrate the phenotypic expression of a lethal recessive allele in a wild population of conservation concern, and provide a general framework for inferring allele distribution and persistence and informing management responses.

opencc-zeroDec 2012View details →

Data from: Phylogeography of the reed frog Hyperolius castaneus (Anura: Hyperoliidae) from the Albertine Rift of Central Africa: implications for taxonomy, biogeography and conservation

We examine the systematics of multiple populations of the Albertine Rift endemic amphibian Hyperolius castaneus, which currently incorporates four subspecies. Standard morphometric data were analyzed with principal components analyses and analyses of covariance. Phylogenetic analyses of two mitochondrial (16S, cyt b) and one nuclear (RAG1) genes were analyzed from 41 samples representing three subspecies. Results indicated some significant morphometric differences between the nominate subspecies H. c. castaneus and the Itombwe Plateau subspecies H. c. constellatus, and phylogenetic analyses of molecular data recovered these taxa as reciprocally monophyletic groups. We recognize these two allopatric populations as recently diverged, but distinct species, H. castaneus and H. constellatus. The subspecies H. c. submarginatus from the Kabobo Plateau is transferred to the synonymy of H. constellatus, but the status of the unsampled subspecies H. c. rhodogaster, described from mid-elevations of the western Itombwe Plateau, remains problematic. The phylogeographic pattern of our study resembles some, but not all, Albertine Rift vertebrates that have been examined with molecular data. Hyperolius constellatus is restricted to the Itombwe and Kabobo plateaus, which are of special conservation concern because of high levels of amphibian diversity and endemism, and multiple threats from deforestation, mining activities and road construction.

Data from: Seascape genetics and biophysical connectivity modelling support conservation of the seagrass Zostera marina in the Skagerrak-Kattegat region of the eastern North Sea

Maintaining and enabling evolutionary processes within meta-populations is critical to resistance, resilience and adaptive potential. Knowledge about which populations act as sources or sinks, and the direction of gene flow, can help to focus conservation efforts more effectively and forecast how populations might respond to future anthropogenic and environmental pressures. As a foundation species and habitat provider, Zostera marina (eelgrass) is of critical importance to ecosystem functions including fisheries. Here we estimate connectivity of Z. marina in the Skagerrak-Kattegat region of the North Sea based on genetic and biophysical modelling. Genetic diversity, population structure and migration were analysed at 23 locations using 20 microsatellite loci and a suite of analytical approaches. Oceanographic connectivity was analysed using Lagrangian dispersal simulations based on contemporary and historical distribution data dating back to the late 19th century. Population clusters, barriers and networks of connectivity were found to be very similar based on either genetic or oceanographic analyses. A single-generation model of dispersal was not realistic, whereas multi-generation models that integrate stepping-stone dispersal and extant and historic distribution data were able to capture and model genetic connectivity patterns well. Passive rafting of flowering shoots along oceanographic currents is the main driver of gene flow at this spatial-temporal scale and extant genetic connectivity strongly reflects the "ghost of dispersal past" sensu Benzie 1999. The identification of distinct clusters, connectivity hotspots and areas where connectivity has become limited over the last century is critical information for spatial management, conservation and restoration of eelgrass.

opencc-zeroDec 2017View details →

Data from: Conservation value of low-productive forests measured as the amount and diversity of dead wood and saproxylic beetles

In many managed landscapes, low-productive land comprises most of the remaining relatively untouched areas, and is often over-represented within protected areas. The relationship between the productivity and conservational value of a site is poorly known; however, it has been hypothesized that biodiversity increases with productivity due to higher resource abundance or heterogeneity, and that the species communities of low-productive land are a nested sub-set of communities from more productive land. We tested these hypotheses for dead wood-dependent beetles by comparing their species richness and composition, as well as the amount and diversity of dead wood, between low-productive (potential forest growth < 1 m3 ha-1 year-1) and productive Scots pine-dominated stands in Sweden. We included four stand types: stands situated on (i) thin soils and (ii) mires (both low-productive), (iii) managed stands, and (iv) unmanaged stands set aside for conservation purposes (both productive). Beetle species richness and number of red-listed species were highest in the productive set-asides. Species richness was positively correlated with the volume and diversity of dead wood, but volume appeared to be a better predictor than diversity for the higher species richness in set-asides. Beetle species composition was similar among stand types, and the assemblages in low-productive stands were largely subsets of those in productive set-asides. However, 11% of all species and 40% of red-listed species only occurred in productive stands, while no species were unique to low-productive stands. We conclude that low-productive forests are less valuable for conservation than productive forest land. Given the generally similar species composition among stand types, a comparable conservational effect could be obtained by setting aside a larger area of low-productive forest in comparison to the productive. In terms of dead wood volumes, 1.8–3.6 ha of low-productive forest has the same value as 1 ha of unmanaged productive forest. This figure can be used to estimate the conservation value of low productive forests; however, as productive forests harbored some unique species, they are not completely exchangeable.

Data from: A generalizable energetics-based model of avian migration to facilitate continental-scale waterbird conservation

Conserving migratory birds is made especially difficult because of movement among spatially disparate locations across the annual cycle. In light of challenges presented by the scale and ecology of migratory birds, successful conservation requires integrating objectives, management, and monitoring across scales, from local management units to ecoregional and flyway administrative boundaries. We present an integrated approach using a spatially explicit energetic-based mechanistic bird migration model useful to conservation decision-making across disparate scales and locations. This model moves a Mallard-like bird (Anas platyrhynchos), through spring and fall migration as a function of caloric gains and losses across a continental-scale energy landscape. We predicted with this model that fall migration, where birds moved from breeding to wintering habitat, took a mean of 27.5 d of flight with a mean seasonal survivorship of 90.5% (95% CI = 89.2%, 91.9%), whereas spring migration took a mean of 23.5 d of flight with mean seasonal survivorship of 93.6% (95% CI = 92.5%, 94.7%). Sensitivity analyses suggested that survival during migration was sensitive to flight speed, flight cost, the amount of energy the animal could carry, and the spatial pattern of energy availability, but generally insensitive to total energy availability per se. Nevertheless, continental patterns in the bird-use days occurred principally in relation to wetland cover and agricultural habitat in the fall. Bird-use days were highest in both spring and fall in the Mississippi Alluvial Valley and along the coast and near-shore environments of South Carolina. Spatial sensitivity analyses suggested that locations nearer to migratory endpoints were less important to survivorship; for instance, removing energy from a 1036 km2 stopover site at a time from the Atlantic Flyway suggested coastal areas between New Jersey and North Carolina, including the Chesapeake Bay and the North Carolina piedmont, are essential locations for efficient migration and increasing survivorship during spring migration but not locations in Ontario and Massachusetts. This sort of spatially explicit information may allow decision-makers to prioritize their conservation actions toward locations most influential to migratory success. Thus, this mechanistic model of avian migration provides a decision-analytic medium integrating the potential consequences of local actions to flyway-scale phenomena.

Data from: Next-generation freshwater bioassessment: eDNA metabarcoding with a conserved metazoan primer reveals species-rich and reservoir-specific communities

Freshwater habitats are of high conservation value and provide a wide range of ecosystem services. Effective management requires regular monitoring. However, conventional methods based on direct observation or specimen collection are so invasive, expensive and labour-intensive that frequent monitoring is uncommon. Here, we test whether the evaluation of environmental DNA (eDNA) from water based on a simple protocol can be used for assessing biodiversity. We use universal metazoan primers for characterizing water eDNA across horizontal and vertical spatial dimensions in two reservoirs with known species diversity for two key taxa. eDNA obtained directly from 42 samples × 15 ml water (total = 630 ml) per reservoir yielded DNA signatures for more than 500 metazoan species, of which 105 could be identified to species/genus based on DNA barcodes. We show that eDNA can be used to assign each water sample to its reservoir of origin, and that eDNA outperforms conventional survey methods in single-sample richness comparisons, while revealing evidence for hundreds of unknown species that are undetected by conventional bioassessment methods. eDNA also confirms the presence of a recently discovered invasive snail species and provides evidence for the continued survival of a rare native species of goby not sighted in that habitat since 2007. eDNA thus promises to be a useful addition to the bioassessment toolbox for freshwater systems.

opencc-zeroDec 2017View details →

Data from: Walking in a heterogeneous landscape: dispersal, gene-flow and conservation implications for the giant panda in the Qinling Mountains

Understanding the interaction between life history, demography and population genetics in threatened species is critical for the conservations of viable populations. In the context of habitat loss and fragmentation, identifying the factors that underpin the structuring of genetic variation within populations can allow conservationists to evaluate habitat quality and connectivity and help to design dispersal corridors effectively. In this study, we carried out a detailed, fine-scale landscape genetic investigation of a giant panda population for the first time, using a large microsatellite data set and examined the role of isolation-by-barriers (IBB), isolation-by-distance (IBD) and isolation-by-resistance (IBR) in shaping the genetic variation pattern of giant pandas in the Qinling Mountains. We found that the Qinling population comprises one continuous genetic cluster, and among the landscape hypotheses tested, gene flow was found to be correlated with resistance gradients for two topographic factors, rather than geographical distance or barriers. Gene-flow was inferred to be facilitated by easterly slope aspect and to be constrained by land surface with high topographic complexity. These factors are related to benign micro-climatic conditions for both the pandas and the food resources they rely on and more accessible topographic conditions for movement, respectively. We identified optimal corridors based on these results, aiming to promote gene flow between human-induced habitat fragments. These findings provide insight into the permeability and affinities of the giant panda habitat and offer important reference for the conservation of the giant panda and its habitat.

opencc-zeroDec 2013View details →

Data from: Spatial and temporal patterns of frugivorous Hornbill movements in Central Africa and their implications for rain forest conservation

Tropical forest conservation and restoration require an understanding of the movements and habitat preferences of important seed dispersers. With forests now being altered at an unprecedented rate, avian frugivores are becoming increasingly vital for forest regeneration. Seed movement, however, is highly dependent on the behavioral characteristics of their dispersers. Here, we examined the movements, habitat preferences, and range sizes of two African frugivores: the Black-casqued (Ceratogymna atrata) and the White-thighed (Bycanistes albotibialis) Hornbill, in the lowland rain forests of southern Cameroon. Using satellite transmitters, we tracked eight hornbills for 3 yr to characterize their movements and relate them to environmental landscape features. Hornbill movements differed significantly, with B. albotibialis ranging over larger areas (mean = 20,274 ha) than C. atrata (mean = 5604 ha), and females of both species covering over 15 times the area of males. Evidence suggests that movements are irruptive during particular periods, perhaps driven by low resource availability. In addition, hornbills often returned to the same localities within a year, although movements were not characterized as migratory. Both species displayed significant differences in habitat preference, with B. albotibialis utilizing disturbed habitat more frequently than C. atrata (t = −22.04, P = 2.2 × 10−16). Major roads were found to act as barriers for C. atrata, but not for B. albotibialis. The ability of both hornbill species to move large distances suggests hornbills will play a vital role in the maintenance and regeneration of rain forests in Central Africa as forest fragmentation increases and terrestrial vertebrates decline in numbers.

Data from: Landscape genetics informs mesohabitat preference and conservation priorities for a surrogate indicator species in a highly fragmented river system

Poor dispersal species represent conservative benchmarks for biodiversity management because they provide insights into ecological processes influenced by habitat fragmentation that are less evident in more dispersive organisms. Here we used the poorly dispersive and threatened river blackfish (Gadopsis marmoratus) as a surrogate indicator system for assessing the effects of fragmentation in highly modified river basins and for prioritizing basin-wide management strategies. We combined individual, population and landscape-based approaches to analyze genetic variation in samples spanning the distribution of the species in Australia's Murray–Darling Basin, one of the world's most degraded freshwater systems. Our results indicate that G. marmoratus displays the hallmark of severe habitat fragmentation with notably scattered, small and demographically isolated populations with very low genetic diversity—a pattern found not only between regions and catchments but also between streams within catchments. By using hierarchically nested population sampling and assessing relationships between genetic uniqueness and genetic diversity across populations, we developed a spatial management framework that includes the selection of populations in need of genetic rescue. Landscape genetics provided an environmental criterion to identify associations between landscape features and ecological processes. Our results further our understanding of the impact that habitat quality and quantity has on habitat specialists with similarly low dispersal. They should also have practical applications for prioritizing both large- and small-scale conservation management actions for organisms inhabiting highly fragmented ecosystems.