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Data from: Age‐dependent habitat relationships of a burned forest specialist emphasise the role of pyrodiversity in fire management

1. Variation in fire characteristics, termed pyrodiversity, plays an important role in structuring post-fire communities, but little is known about the importance of pyrodiversity for individual species. The availability of diverse post-fire habitats may be key for fire-associated species if they require different resources at different life history stages. 2. We tested for age-specific habitat relationships in the black-backed woodpecker, a post-fire specialist. We used radio-telemetry to track fledgling and adult woodpeckers in burned forests and built resource selection functions to compare the effect of stand-, tree-, and snag-level covariates between adults and fledglings. 3. Fledgling black-backed woodpeckers selected habitat with more live trees than adults, and used more heterogeneous habitats burned at lower severity, illustrating strong age-dependent effects on habitat selection. Within selected stands, fledglings were less likely to use snags and more likely to use live trees when compared to adults, but both age classes showed strong positive selection for larger-diameter trees (live and dead). Over the 60 days after leaving their nests, fledglings showed an increasing propensity to use snags rather than live trees. 4. Our results provide evidence that the predation–starvation hypothesis, which posits a trade-off between foraging efficiency and the need to minimize predation risk, plays a role in structuring the age-dependent habitat use of a burned forest specialist. Adult black-backed woodpeckers selected resources associated with food availability, but these resources occurred in relatively open, exposed habitat. Fledglings selected habitat that provided increased cover, perhaps as a strategy to reduce predation risk. 5. Synthesis and applications. Globally, fires are increasing in severity and extent, leading to increased focus on fire-associated species that play keystone roles in facilitating biodiversity resilience. Our findings suggest that a diversity of patches burned at different severities may benefit post-fire specialists like the black-backed woodpecker at multiple life history stages. The increasing prevalence of large, homogeneously high-severity "megafires" may present an emerging threat even to post-fire specialists, and we urge land managers to consider opportunities to promote pyrodiversity in the face of novel fire regimes.

opencc-zeroDec 2012View details →

Data from: Discovery and characterization of novel genetic markers for use in the management of Lahontan cutthroat trout (Oncorhynchus clarkii henshawi)

The Lahontan cutthroat trout (Oncorhynchus clarkii henshawi) is threatened by habitat destruction, over-harvest and hybridization with nonnative trout. Currently, three Geographic Management Units (GMUs) are recognized within the taxon. Here, we describe a suite of 68 single-nucleotide polymorphism (SNP) genetic markers for use in the study and management of Lahontan cutthroat trout and a closely related subspecies, the Paiute cutthroat trout (O. c. seleneris). These include markers variable within the two subspecies (n = 35), diagnostic for the two subspecies (n = 23) and diagnostic for Yellowstone cutthroat trout (O. c. bouvieri) and other closely related subspecies (n = 10). Sixty-three markers were discovered by Sanger sequencing of 171 EST loci in an ascertainment panel including Lahontan cutthroat trout from four populations representing all GMUs. Five markers were identified in a secondary sequencing effort with a single population of Lahontan cutthroat trout. TaqMan assays were validated on six Lahontan cutthroat trout populations and a diverse panel of other trout. Over 90% of the markers variable in Lahontan cutthroat trout were polymorphic in at least two populations, and 66% were variable within all three GMUs. All Lahontan diagnostic markers were also fixed for the Lahontan allele in Paiute cutthroat trout. Most of the Yellowstone diagnostic markers can also be used for this purpose in other cutthroat trout subspecies. This is the first set of SNP markers to be developed for Lahontan cutthroat trout, and will be an important tool for conservation and management.

Data from: Effects of small-scale, shading-induced seagrass loss on blue carbon storage: Implications for management of degraded seagrass ecosystems

1. Seagrass meadows are important global 'blue carbon' sinks. Despite a 30% loss of seagrasses globally during the last century, there is limited empirical research investigating the effects of disturbance and loss of seagrass on blue carbon stocks. 2. In this study, we hypothesised that seagrass loss would reduce blue carbon stocks. Using shading cloth, we simulated small-scale die-offs of two subtropical seagrass species, Halodule wrightii and Thalassia testudinum, in a dynamic northern Gulf of Mexico lagoon. The change in quantity and quality of sediment organic matter and organic carbon were compared among kill, control and bare plots before the kill treatment, shortly after the kill treatment and 11 months after the kill treatment. 210 Pb age dating was performed on bare and Thalassia plots at 11 months to evaluate the impact of sediment erosion in the absence of vegetation. 3. The small-scale die-off led to a 50-65% organic matter (OM) loss in the sediment in the top 8 cm of Halodule plots. Thalassia plots lost significant portions OM (50%) and organic carbon (C; 21-47%) in only the top 1 cm of sediment. The 210 Pb profiles indicated Thalassia die-off reduced the C sequestration rate by 10%, in addition to a loss of ~1 years' worth of C stocks (~22 g m-2<). Furthermore, analyses on O Morg quality indicated a loss of labile OM/C and enhanced remineralisation by microbes. 4. Synthesis and applications: This study provides empirical evidence that small-scale shading-induced seagrass die-offs can reduce seagrass carbon sequestration capacity and trigger losses of blue carbon stocks. While the losses recorded here are modest, these losses in blue carbon storage capacity are notable due to the proximity of shading structures (for example, boat docks) to seagrass habitats. Thus, policies to avoid or protect seagrass habitats from common small-scale, shading disturbances are important for optimising both carbon sequestration capacity and coastline development and management.17-Nov-2017

Data from: Environmental DNA for the enumeration and management of Pacific salmon

Pacific salmon are a keystone resource in Alaska, generating annual revenues of well over ~US$500 million/yr. Due to their anadromous life history, adult spawners distribute amongst thousands of streams, posing a huge management challenge. Currently, spawners are enumerated at just a few streams because of reliance on human counters and, rarely, sonar. The ability to detect organisms by shed tissue (environmental DNA, eDNA) promises a more efficient counting method. However, although eDNA correlates generally with local fish abundances, we do not know if eDNA can accurately enumerate salmon. Here we show that daily, and near-daily, flow-corrected eDNA rate closely tracks daily numbers of returning sockeye and coho spawners and outmigrating sockeye smolts. eDNA thus promises accurate and efficient enumeration, but to deliver the most robust numbers will need higher-resolution stream-flow data, at-least-daily sampling, and a focus on species with simple life histories, since shedding rate varies amongst jacks, juveniles, and adults.

Data from: Disturbance intensity is a stronger driver of biomass recovery than remaining tree-community attributes in a managed Amazonian forest

1.Forest recovery following management interventions is important to maintain ecosystem functioning and the provision of ecosystem services. It remains, however, largely unclear how aboveground biomass (AGB) recovery of species-rich tropical forests is affected by disturbance intensity and post-disturbance (remaining) tree-community attributes, following logging and thinning interventions. 2.We investigated whether annual AGB increment (∆AGB) decreases with management-related disturbance intensity (disturbance hypothesis), and increases with the diversity (niche-complementarity hypothesis) and the community-weighted mean (CWM) of acquisitive traits of dominant species (biomass-ratio hypothesis) in the remaining tree community. 3.We analysed data from a long-term forest-management experiment in the Brazilian Amazon over two recovery periods: post-logging (1983-1989) and post-thinning (1995-2012). We computed the ∆AGB of surviving trees, recruit trees and of the total tree community. Disturbance intensity was quantified as basal area reduction and basal area remaining. Remaining diversity (taxonomic, functional and structural) and CWM of five functional traits linked to biomass productivity (specific leaf area, leaf nitrogen and phosphorous concentration, leaf toughness and wood density) were calculated for the post-intervention inventories. Predictors were related to response variables using multiple linear regressions and structural equation modelling. 4.We found support for the disturbance hypothesis in both recovery periods. AGB increment of survivors and of the total tree community increased with basal area remaining, indicating the importance of remaining growing stock for biomass recovery. Conversely, AGB increment of recruit trees increased with basal area reduction because changes in forest structure increased resource availability for young trees. We did not find consistent support for the niche-complementarity and biomass-ratio hypotheses, possibly because of a high redundancy in these extremely species-rich forests. 5.Synthesis and applications. The intensity of disturbance through management, expressed as basal area reduction and basal area remaining, was consistently more important for explaining forest biomass recovery following harvesting and thinning than remaining diversity or trait composition. This points to the importance of controlling logging and thinning intensity in forests of the eastern Amazon. Low to moderate harvesting intensities permitted by the current legislation for the Brazilian Amazon (30 m³ ha−1) will likely not impair biomass recovery in these forests.

Data from: Trade-offs in the multi-use potential of managed boreal forests

1. Implementing multi-use forest management to account for both commercial and non-commercial ecosystem services is gaining increased global recognition. Despite its spatial extent, and great economic and ecological values, few studies have evaluated the boreal forest and its management to assess the potential for simultaneous delivery of a suite of ecosystem services. 2. Using data from a Swedish long-term experiment this study explores how biodiversity of the ground vegetation and potential delivery of multiple ecosystem services (timber production, carbon (C) storage and non-timber forest products) are influenced by two common silvicultural practices (thinning, fertilization and their interaction). 3. Diversity (diversity indices and species richness) of the ground vegetation was higher in thinned than in unthinned forest, something partly explained by six species of lichens that only occurred in thinned forest. In addition, supply of lichens for reindeer forage was three times higher in thinned forest. Fertilization negatively affected the lingonberry shrub (Vaccinium vitis-idaea). Timber production increased with fertilization, but decreased with thinning. The potential for C storage was highest in fertilized forests, which, apart from having the highest timber production, also supported the highest standing tree biomass. 4. The silvicultural practices evaluated induced trade-offs among the ecosystem features studied as thinning increased biodiversity of the ground vegetation, production potential of wild berries and lichens, but reduced timber production and the forest's potential for C storage. Fertilization, had the opposite effect, promoting the potential for C storage at the expense of biodiversity and the ecosystem services delivered by the ground vegetation. 5. Synthesis and applications. Silvicultural practice had a pronounced effect on the multi-use output, and trade-offs among values were common. Nevertheless, our study demonstrates that silvicultural practices that are currently adopted in Sweden can be used to adjust the multi-use potential output of forests, suggesting that commonly used practices can be applied to maintain, or even increase the multi-use potential of the boreal forest biome, if management objectives are allowed to vary across the landscape. A prerequisite for this is site specific management objectives that clearly determine the desired output.

Data from: Quantification of avian hazards to military aircraft and implications for wildlife management

Collisions between birds and military aircraft are common and can have catastrophic effects. Knowledge of relative wildlife hazards to aircraft (the likelihood of aircraft damage when a species is struck) is needed before estimating wildlife strike risk (combined frequency and severity component) at military airfields. Despite annual reviews of wildlife strike trends with civil aviation since the 1990s, little is known about wildlife strike trends for military aircraft. We hypothesized that species relative hazard scores would correlate positively with aircraft type and avian body mass. Only strike records identified to species that occurred within the U.S. (n = 36,979) and involved United States Navy or United States Air Force aircraft were used to calculate relative hazard scores. The most hazardous species to military aircraft was the snow goose (Anser caerulescens), followed by the common loon (Gavia immer), and a tie between Canada goose (Branta canadensis) and black vulture (Coragyps atratus). We found an association between avian body mass and relative hazard score (r2 = 0.76) for all military airframes. In general, relative hazard scores per species were higher for military than civil airframes. An important consideration is that hazard scores can vary depending on aircraft type. We found that avian body mass affected the probability of damage differentially per airframe. In the development of an airfield wildlife management plan, and absent estimates of species strike risk, airport wildlife biologists should prioritize management of species with high relative hazard scores.

Data from: Earthworm activity and availability for meadow birds is restricted in intensively managed grasslands

1. Earthworms are an important prey for the endangered meadow birds of north-west Europe. Although intensive grassland management with high manure inputs generally promotes earthworm abundance, it may reduce the effective food availability for meadow birds through desiccation of the topsoil, which causes earthworms to remain deeper in the soil. 2. We studied the response of Red Worm Lumbricus rubellus, a detritivore, and Grey Worm Aporrectodea caliginosa, a geophage, to soil moisture profiles in the field and under experimental conditions. Surfacing earthworms were counted weekly in eight intensively managed grasslands (treated with high inputs of slurry by slit injection) with variable groundwater tables in the Netherlands. At each count, soil penetration resistance, soil moisture tension and groundwater level were measured, while air temperature and humidity were obtained from a nearby weather station. The response to variation in the vertical distribution of soil moisture was also experimentally studied in the two earthworm species. 3. In the field, earthworms' surfacing activity at night was negatively associated with soil moisture tension and positively by relative air humidity. Surprisingly, there was no effect of groundwater level; an important management variable in meadow bird conservation. Under experimental conditions, both L. rubellus and A. caliginosa moved to deeper soil layers (>20 cm) in drier soil moisture treatments, avoiding the upper layer when moisture levels dropped below 30%. 4. Synthesis and applications. We propose that in intensively managed grasslands with slurry application, topsoil desiccation reduces earthworm availability for meadow birds. This can be counteracted by keeping soil moisture tensions of the top soil above -15 kPa. We suggest that the late raising of groundwater tables in spring and the disturbance of the soil by slit injection of slurry increase topsoil desiccation. This decreases earthworm availability when it matters most for breeding meadow birds. Meadow bird conservation will benefit from revised manure application strategies that promote earthworm activity near or at the soil surface.

Data from: Partitioning drivers of spatial genetic variation for a continuously-distributed population of boreal caribou: implications for management unit delineation

Isolation-by-distance (IBD) is a natural pattern not readily incorporated into theoretical models nor traditional metrics for differentiating populations, although clinal genetic differentiation can be characteristic of many wildlife species. Landscape features can also drive population structure additive to baseline IBD resulting in differentiation through isolation-by-resistance (IBR). We assessed the population genetic structure of boreal caribou across western Canada using non-spatial (STRUCTURE) and spatial (MEMGENE) clustering methods and investigated the relative contribution of IBD and IBR on genetic variation of 1221 boreal caribou multilocus genotypes across western Canada. We further introduced a novel approach to compare the partitioning of individuals into management units (MU) and assessed levels of genetic connectivity under different MU scenarios. STRUCTURE delineated five genetic clusters while MEMGENE identified finer-scale differentiation across the study area. IBD was significant and did not differ for males and females both across and among detected genetic clusters. MEMGENE landscape analysis further quantified the proportion of genetic variation contributed by IBD and IBR patterns, allowing for the relative importance of spatial drivers, including roads, water bodies and wildfires, to be assessed and incorporated into the characterization of population structure for the delineation of MUs. Local population units, as currently delineated in the boreal caribou recovery strategy, do not capture the genetic variation and connectivity of the ecotype across the study area. Here, we provide the tools to assess fine-scale spatial patterns of genetic variation, partition drivers of genetic variation and evaluate the best management options for maintaining genetic connectivity. Our approach is highly relevant to vagile wildlife species that are of management and conservation concern and demonstrate varying degrees of IBD and IBR with clinal spatial genetic structure that challenges the delineation of discrete population boundaries.

opencc-zeroMay 2019View details →

Data from: Allocation of invasive plant management expenditures for conservation: lessons from Florida, USA

Although the ecological impacts of biological invasions are well studied, comprehensive analyses of spending on invasive species management are lacking. Such analyses could inform both effective resource allocation and management planning. We evaluated long-term invasive plant management expenditures and their potential geographic, economic, and ecological drivers for freshwater and terrestrial conservation areas in Florida, USA. Average expenditures for managing invaders were approximately US$45M annually, with over 90% of funding provided by the state. Our model showed that expenditures were best predicted by the prevalence of waterways and abundance of invaders, indicating that funding was allocated towards asset protection in highly-invaded aquatic and terrestrial habitats. Higher spending was directly correlated with reduced area invaded for the costliest invader (Hydrilla verticillata, ~$10M/year), demonstrating management efficacy and constructive use of resources. Our study highlights that significant funding is required to manage plant invaders in Florida and that greater funding would likely limit the extent of invasions. Additional analyses of management cost-effectiveness for Florida and other regions would benefit from consistent collection and reporting of high-resolution management data. Given the exponential rate of spread of many invaders, additional and sustained management funding is needed for early detection and rapid, effective control of invasive species.

Data from: Diversifying livestock promotes multidiversity and multifunctionality in managed grasslands

Increasing plant diversity can increase ecosystem functioning,stability, and services in both natural and managed grasslands,but the effects of herbivore diversity, and especially of livestock diversity, remain underexplored. Given that managed grazing is the most extensive land use worldwide, and that land managers can readily change livestock diversity, we experimentally tested how livestock diversification (sheep, cattle, or both) influenced multidiversity (the diversity of plants, insects, soil microbes, and nematodes) and ecosystem multifunctionality (including plant biomass production, plant leaf N and P, above-ground insect abundance, nutrient cycling, soil C stocks, water regulation, and plant–microbe symbiosis) in the world's largest remaining grassland. We also considered the potential dependence of ecosystem multifunctionality on multidiversity. We found that livestock diversification substantially increased ecosystem multifunctionality by increasing multidiversity. The link between multidiversity and ecosystem multifunctionality was always stronger than the link between single diversity components and functions. Our work provides insights into the importance of multitrophic diversity to maintain multifunctionality in managed ecosystems and suggests that diversifying livestock could promote both multidiversity and ecosystem multifunctionality in an increasingly managed world.

Data from: Value of information in natural resource management: technical developments and application to pink-footed geese

The "value of information" (VOI) is a generic term for the increase in value resulting from better information to guide management, or alternatively, the value foregone under uncertainty about the impacts of management (Yokota and Thompson, Medical Decision Making 2004; 24: 287). The value of information can be characterized in terms of several metrics, including the expected value of perfect information and the expected value of partial information. We extend the technical framework for the value of information by further developing the relationship between value metrics for partial and perfect information and describing patterns of their performance. We use two different expressions for the expected value of partial information to highlight its relationship to the expected value of perfect information. We also develop the expected value of partial information for hierarchical uncertainties. We highlight patterns in the value of information for the Svalbard population of the pink-footed goose (Anser brachyrhynchus), a population that is subject to uncertainty in both reproduction and survival functions. The framework for valuing information is seen as having widespread potential in resource decision making, and serves as a motivation for resource monitoring, assessment, and collaboration.

Data from: A parallel population genomic and hydrodynamic approach to fishery management of highly-dispersive marine invertebrates: the case of the Fijian black-lip pearl oyster Pinctada margaritifera

Fishery management and conservation of marine species increasingly relies on genetic data to delineate biologically relevant stock boundaries. Unfortunately for high gene flow species which may display low, but statistically significant population structure, there is no clear consensus on the level of differentiation required to resolve distinct stocks. The use of fine-scale neutral and adaptive variation, considered together with environmental data can offer additional insights to this problem. Genome-wide genetic data (4,123 SNPs), together with an independent hydrodynamic particle dispersal model were used to inform farm and fishery management in the Fijian black-lip pearl oyster Pinctada margaritifera, where comprehensive fishery management is lacking, and the sustainability of exploitation uncertain. Weak fine-scale patterns of population structure were detected, indicative of broad-scale panmixia among wild oysters, while a hatchery-sourced farmed population exhibited a higher degree of genetic divergence (Fst = 0.0850–0.102). This hatchery-produced population had also experienced a bottleneck (NeLD = 5.1; 95% C.I. = [5.1–5.3]); compared to infinite NeLD estimates for all wild oysters. Simulation of larval transport pathways confirmed the existence of broad-scale mixture by surface ocean currents, correlating well with fine-scale patterns of population structuring. Fst outlier tests failed to detect large numbers of loci supportive of selection, with 2–5 directional outlier SNPs identified (average Fst = 0.116). The lack of biologically significant population genetic structure, absence of evidence for local adaptation and larval dispersal simulation, all indicate the existence of a single genetic stock of P. margaritifera in the Fiji Islands. This approach using independent genomic and oceanographic tools has allowed fundamental insights into stock structure in this species, with transferability to other highly-dispersive marine taxa for their conservation and management.

Data from: Ecological disturbance influences adaptive divergence despite high gene flow in golden perch (Macquaria ambigua): implications for management and resilience to climate change

Populations that are adaptively divergent but maintain high gene flow may have greater resilience to environmental change as gene flow allows the spread of alleles that have already been tested elsewhere. In addition, populations naturally subjected to ecological disturbance may already hold resilience to future environmental change. Confirming this necessitates ecological genomic studies of high dispersal, generalist species. Here we perform one such study on golden perch (Macquaria ambigua) in the Murray-Darling Basin (MDB), Australia using a genome-wide SNP dataset. The MDB spans across arid to wet and temperate to sub-tropical environments, with low to high ecological disturbance in the form of low to high hydrological variability. We found high gene flow across the basin and three populations with low neutral differentiation. Genotype-environment association analyses detected adaptive divergence predominantly linked to an arid region with highly variable riverine flow, and candidate loci included functions related to fat storage, stress and molecular or tissue repair. The high connectivity of golden perch in the MDB will likely allow locally adaptive traits in its most arid and hydrologically variable environment to spread and be selected in localities that are predicted to become arid and hydrologically variable in future climates. High connectivity in golden perch is likely due to their generalist life history and efforts of fisheries management. Our study adds to growing evidence of adaptation in the face of gene flow, and highlights the importance of considering ecological disturbance and adaptive divergence in biodiversity management.

Data from: Managing Neotropical oil palm expansion to retain phylogenetic diversity

The expansion of tropical agriculture is a major driver of the extinction crisis. A key question is whether biodiversity losses can be minimized by restricting future expansion to low-productivity farmland and retaining forest fragments, especially in rapidly changing Neotropical landscapes. We investigated these methods in the context of avian phylogenetic diversity, which summarizes the evolutionary history preserved within communities. Evidence suggests that phylogenetic diversity plays an important role in maintaining key ecosystem functions. We collected data on avian communities in the Colombian Llanos, a region highlighted as being optimal for the expansion of oil palm, at the expense of existing habitats including forest remnants and improved cattle pastures. PD, a measure of phylogenetic richness, and MPD, a measure of the phylogenetic distance between individuals in a community in deep evolutionary time, were significantly higher in forest than in oil palm or pasture, but did not differ significantly between oil palm and pasture. MNTD, a measure of distance between individuals in a community at the intra-familial and intra-generic level, was significantly higher in oil palm and pasture than in forest. However, median evolutionary distinctiveness (ED) was highest in pasture, partly due to the abundance of distinct waterbirds, but did not differ between oil palm and forest. PD in oil palm and pasture increased with the extent of remnant forest cover. Synthesis and applications. The PD (a measure of phylogenetic richness) and MPD (a measure of the phylogenetic distance) of bird communities in this region can best be conserved by ensuring that new oil palm plantations replace pasturelands rather than forest. A secondary benefit of preserving forest would be the enhancement of PD in the surrounding agricultural landscape. This strategy will need to be coupled with measures to either reduce pasture demand or to intensify existing cattle production to ensure that forest is not replaced by pasture elsewhere.

Data from: Black abalone (Haliotis cracherodii) population structure shifts through deep time: Management implications for southern California's northern Channel Islands

For over 10,000 years, black abalone (Haliotis cracherodii) were an important resource in southern California, first for coastal Native Americans, then beginning in the nineteenth century, as one of the state's first commercial shellfisheries. By 1993, after years of heavy fishing, rising sea surface temperatures (SST), and the spread of withering syndrome (WS), black abalone populations declined dramatically, resulting in the closure of the Alta California fishery. After nearly 25 years of management and recovery efforts, black abalone are showing signs of ecological rebound along some Channel Island shorelines. These include the presence of juvenile abalone and increasing densities, largely from data collected by Channel Islands National Park (CINP) monitoring efforts that began in 1985. In an effort to apply deeper historical perspectives to modern fisheries management and restoration, we analyzed black abalone size data from San Miguel Island at prehistoric and historical archeological sites spanning the last 10,000 years and compared these populations to those described by CINP biologists between 1985 and 2013. We found a statistically significant relationship between SST and black abalone size distributions during the ancient record, along with dramatic shifts in population size structure toward larger individuals between the nineteenth century and modern periods. A pattern of larger mean black abalone sizes was identified during warm SSTs, when compared against intervals of cooler SSTs. Synthesis and applications. Our study provides a deep historical perspective of abalone population size distributions, patterns within these distributions through time, and parallels to modern abalone populations. Our results may help managers determine whether the current (and future) size and age structure of intertidal black abalone populations around the northern Channel Islands are "natural" and healthy, measured against the 10,000 year history of black abalone fishing in southern California.

Data from: Managing more than the mean: using quantile regression to identify factors related to large elk groups

1. Animal group size distributions are often right-skewed, whereby most groups are small, but most individuals occur in larger groups that may also disproportionately affect ecology and policy. In this case, examining covariates associated with upper quantiles of the group size distribution could facilitate better understanding and management of large animal groups. 2. We studied wintering elk groups in Wyoming, where group sizes span several orders of magnitude, and issues of disease, predation and property damage are affected by larger group sizes. We used quantile regression to evaluate relationships between the group size distribution and variables of land use, habitat, elk density and wolf abundance to identify conditions important to larger elk groups. 3. We recorded 1263 groups ranging from 1 to 1952 elk and found that across all quantiles of group size, group sizes were larger in open habitat and on private land, but the largest effect occurred between irrigated and non-irrigated land [e.g. the 90th quantile group size increased by 135 elk (95% CI = 42, 227) on irrigation]. 4. Only upper quantile group sizes were positively related to broad-scale measures of elk density and wolf abundance. For wolf abundance, this effect was greater on elk groups found in open habitats and private land than those in closed habitats or public land. If we had limited our analysis to mean or median group sizes, we would not have detected these effects. 5. Synthesis and applications. Our analysis of elk group size distributions using quantile regression suggests that private land, irrigation, open habitat, elk density and wolf abundance can affect large elk group sizes. Thus, to manage larger groups by removal or dispersal of individuals, we recommend incentivizing hunting on private land (particularly if irrigated) during the regular and late hunting seasons, promoting tolerance of wolves on private land (if elk aggregate in these areas to avoid wolves) and creating more winter range and varied habitats. Relationships to the variables of interest also differed by quantile, highlighting the importance of using quantile regression to examine response variables more completely to uncover relationships important to conservation and management.

Data from: Bias associated with the detectability of the coral-eating pest crown-of-thorns seastar and implications for reef management

Outbreaks of the predator crown-of-thorns seastar (COTS) Acanthaster planci cause widespread coral mortality across the Indo-Pacific. Like many marine invertebrates, COTS is a nocturnal species whose cryptic behaviour during the day can affect its detectability, particularly in structurally complex reef habitats that provide many refuges for benthic creatures. We performed extensive day and night surveys of COTS populations in coral reef habitats showing differing levels of structural complexity and COTS abundance. We tested whether estimations of COTS density varied between day and night observations, and if the differences were related to changes in COTS abundance, reef structural complexity, and the spatial scale of observation. Estimations of COTS density were on average 27% higher at night than during the day. Differences in COTS detection varied with changing seastar abundance but not reef structural complexity or scale of observation. Underestimation of COTS abundance in daytime was significant for a broad seastar density range, thus potentially affecting most outbreak events. Our study suggests that portions of COTS populations can be undetected during conventional surveys and control campaigns, which are exclusively conducted by day, and significantly affect the trajectory of coral reefs. Accounting for bias in COTS detection can strengthen coral reef management broadly.

Data from: Flower resource and land management drives hoverfly communities and bee abundance in semi-natural and agricultural grasslands

1. Pollination is a key ecosystem service, and appropriate management, particularly in agricultural systems, is essential to maintain a diversity of pollinator guilds. However, management recommendations frequently focus on maintaining plant communities, with the assumption that associated invertebrate populations will be sustained. 2. We tested whether plant community, flower resources and soil moisture would influence hoverfly (Syrphidae) abundance and species richness in floristically-rich semi-natural and floristically-impoverished agricultural grassland communities in Wales (U.K.), and compared these to two Hymenoptera genera, Bombus and Lasioglossum. Interactions between environmental variables were tested using generalised linear modelling, and hoverfly community composition examined using canonical correspondence analysis. 3. There was no difference in hoverfly abundance, species richness, or bee abundance, between grassland types. There was a positive association between hoverfly abundance, species richness and flower abundance in unimproved grasslands. However, this was not evident in agriculturally improved grassland, possibly reflecting intrinsically low flower resource in these habitats, or the presence of plant species with low or relatively inaccessible nectar resources. There was no association between soil moisture content and hoverfly abundance or species richness. 4. Hoverfly community composition was influenced by agricultural improvement and the amount of flower resource. Hoverfly species with semi-aquatic larvae were associated with both semi-natural and agricultural wet grasslands, possibly because of localised larval habitat. Despite the absence of differences in hoverfly abundance and species-richness, distinct hoverfly communities are associated with marshy grasslands, agriculturally improved marshy grasslands and unimproved dry grasslands, but not with improved dry grasslands. 5. Grassland plant community cannot be used as a proxy for pollinator community. Management of grasslands should aim to maximise the pollinator feeding resource, as well as maintain plant communities. Retaining waterlogged ground may enhance the number of hoverflies with semi-aquatic larvae.

Data from: The impact of conservation management on the community composition of multiple organism groups in eutrophic interconnected man-made ponds

Ponds throughout the world are subjected to a variety of management measures for purposes of biodiversity conservation. Current conservation efforts typically comprise a combination of multiple measures that directly and indirectly impact a wide range of organism groups. Knowledge of the relative impact of individual measures on different taxonomic groups is important for the development of effective conservation programs. We conducted a field study of 28 man-made ponds, representing four management types differing in the frequency of periodic pond drainage and the intensity of fish stock management. We disentangled the relative importance of direct and indirect effects of pond management measures on the community composition of phytoplankton, zooplankton, aquatic macro-invertebrates, submerged and emergent vascular plants. With the exception of phytoplankton, pond management had strong effects on the community composition of all investigated biota. Whether management affected communities directly or indirectly through its impact on fish communities or local environmental conditions in the pond varied between organism groups. Overall, the impact of pond drainage regime and fish community characteristics on the community composition of target organism groups were more important than local environmental conditions. The majority of taxa were negatively associated with fish density, whereas multiple emergent plant species and several taxa of aquatic macro-invertebrates were positively affected by increased drainage frequency. The effects of fish community and drainage tended to be largely independent. The present study indicates that pond drainage is an important element for biodiversity conservation in eutrophicated shallow and interconnected man-made ponds.