Upland Birds Research Articles

Active forest stewardship benefits priority birds in the New Jersey Pine Barrens.

Fire suppression has negatively impacted thousands of acres of private and public lands in the United States. As a case study, the New Jersey Pine Barrens (NJPB) are a disturbance driven ecosystem that is experiencing serious ecological implications due to a loss of traditional forest thinning activities such as harvesting for forest products or thinning for wildfire fuel-load reduction measures coupled with a long-standing philosophy of fire suppression and dormant-season prescribed burning. Dense closed-canopy forest conditions, dissimilar to historic open-canopy forests of the NJPB, have reduced abundance and diversity of certain flora and fauna, including regionally imperiled breeding birds. In recent years, active forest stewardship (e.g., thinning, clear-cutting, and burning) has occurred on private and some public lands within the NJPB; however, the impact of such management on breeding birds is unclear due to a paucity of research on this subject within the NJPB. During 2012, 2013, 2016, and 2017, we conducted repeat-visit point counts (n = 1,800) for breeding songbirds across 75 control and 75 treatment sites within the NJPB to assess the influence of forest structure at three strata levels (groundcover, midstory profile, and canopy) on breeding bird communities. Specifically, we constructed a hierarchical community abundance model within a Bayesian framework for Bird Conservation Region (BCR) 30 priority upland birds (n = 12) within three species suites: Forested Upland, Scrub-Shrub (or Young Forest), and Grassland. At the community level, we found a negative relationship between bird abundance and live tree basal area. At the BCR 30 suite level, we found no relationship between Forested Upland suite-level abundance and any of the measured covariates; however, we found a negative relationship between percentage of woody groundcover and Scrub-Shrub suite-level abundance, and negative relationship between horizontal visual obstruction at 2 m above ground level and Grassland suite-level abundance. Furthermore, the two latter species suites exhibited a strong negative relationship with basal area. We recommend active forest stewardship that specifically targets opening the canopy to achieve basal areas between ~0-15 m2/ha via selective thinning, shelter cutting, and small-scale clear cutting. Mechanical treatment and prescribed burning would produce such conditions and have the added benefit of reducing fuel loads across this ~4,500 km2 landscape as well as assisting in carbon defense strategies for the region.

The foraging ecology of yellow-billed and red- billed choughs changed between two climatically different years

Climate change is affecting the alpine ecosystem at an unprecedented rate, with marked changes in spring phenology and the elevation distribution of birds. Changes in the European Alps are happening rapidly, and it is possible behaviours stand to change from one year to the next. The year 2022 was characterised by climatic extremes: Italy experienced its hottest year ever, and it was the driest since 1800. Here, we assessed whether the foraging ecology of two coexisting upland bird species, the yellow-billed and the red-billed chough, changed from 2021 to 2022. We assessed foraging stay times, flock size, propensity to mixed flocking, foraging home ranges and altitudinal distribution. Stay times of both species when foraging in monospecific flocks significantly shortened in 2022, especially in the case of the red-billed chough. The two corvids are known to influence each other when foraging together. In 2021, as expected, the stay times of the red-billed chough decreased when in the presence of the congener, but this did not occur in 2022. Instead, the yellow-billed chough increased its altitudinal foraging distribution in 2022. The results are in line with the hypothesis that large climate variations may disrupt the foraging ecology of mountain birds. However, as it is not possible to draw solid conclusions from just two years of observations, further field research will have to be planned in the future.

Low species turnover of upland Amazonian birds in the absence of physical barriers

AbstractAimOne of the oldest and most powerful ways for ecologists to explain distinct biological communities is to invoke underlying environmental differences. But in hyper‐diverse systems, which often display high species richness and low species abundance, these sorts of community comparisons are especially challenging. The classic view for Amazonian birds posits that riverine barriers and habitat specialization determine local and regional community composition. We test the tacit, complementary assumption that similar bird communities should therefore permeate uniform habitat between major rivers, regardless of distance.LocationUpland (terra firme) rainforests of central Amazonia.MethodsWe conducted intensive whole‐community surveys of birds in three pairs of 100‐ha plots, separated by 40–60 km. We then used dissimilarity indices, cluster analysis, and ordination to characterize differences among the six avian communities.ResultsIn all, we detected 244 forest‐dependent birds, with an average of 190 species (78%) per plot. Species turnover was negligible, no unique indicator species were found among plot pairs, and all documented species were already known from a complete inventory at one of the three sites.Main ConclusionsOur study corroborates the classic biogeographical pattern and suggests that turnover contributes little to regional avian diversity within upland forests. Using a grain size of 100 ha, this implies that upland birds perceive the environment as uniform, at least over distances of ~60 km. Therefore, to maximize both local species richness and population persistence, our findings support the conservation of very large tracts of upland rainforest. Our analyses also revealed that the avifauna at Reserva Ducke, encroached by urban sprawl from the city of Manaus, shows the hallmarks of a disturbed community, with fewer vulnerable insectivores. This defaunation signals that even an enormous preserve (10 × 10 km) in lowland Amazonia is not insulated from anthropogenic degradation within the surrounding landscape.

Cenozoic weathering of fluvial terraces and emergence of biogeographic boundaries in Central Amazonia

The study of paleofluvial dynamics is crucial to understand the role of rivers as biogeographic boundaries in Amazonia during the Cenozoic. In central Amazonia, Mesozoic and Cenozoic fluvial deposits - Alter do Chão, Iranduba and Novo Remanso Formations - host supergene iron oxides and record changes in the distribution of flooded and non-flooded (upland) environments. Geochronological data on these deposits are still scarce to constrain past landscape changes. Therefore, in this study we investigate iron oxides precipitated within weathering profiles developed on ancient fluvial terraces to access the interplay between flooded and non-flooded environments in central Amazonia. We aimed to trace the history of abandonment of alluvial plains and the subsequent weathering of lowland sediment deposits during the Cenozoic. We identified at least two main periods of iron oxide precipitation: (1) one starting before ~42 Ma and ending at ~18 Ma; and (2) a well-defined humid and weathering prone phase between ~8 and 1 Ma. Dominant goethite precipitation marks a major climatic shift towards more humid conditions from ~3 Ma. The increase in water discharge of the Negro and Solimões rivers possibly promoted fluvial incision and conversion of floodplains into long-lasting upland terrains as indicated by the development of lateritic weathering profiles. This major phase of upland expansion corroborates upland birds phylogenetic data, which indicate the emergence of a major biogeographic barrier in central Amazonia during late Pliocene/Pleistocene. • Refining the age of the fluvial sedimentary units in central Amazonia • Multiple Cenozoic discrete weathering phases in central Amazonia • Linking weathering phases with fluvial landscape changes • Constraining the emergence of a major biogeographic boundary

Drivers of change in mountain and upland bird populations in Europe

Mountain ecosystems have special significance for biodiversity and are vulnerable to climate and other environmental changes. However, few assessments of drivers of change have been conducted in these areas in comparison to other more accessible biomes. In this study, we developed an objective and broad definition of a mountain bird, and systematically reviewed the existing literature for the 34 European mountain and upland species identified in order to quantify which drivers of environmental change have been most consistently associated with positive or negative demographic responses. Raptors and gamebirds were the most‐studied species, whereas mountain specialists and arctic–alpine species were little studied. Using a standardized threat classification, the analyses reported significant negative impacts of hunting, collision with energy‐generation infrastructures, predation by competitive species, human disturbance and poisoning. There were significant positive effects for management of non‐target species, but less support for effects of drivers operating over longer timescales, such as climate and land‐use changes. Analysis of trends in drivers found evidence of increasing temperatures and vegetation encroachment, whereas agricultural impacts decreased, which was largely related to abandonment of grazing. A lack of fine‐grained studies investigating ecological mechanisms and population responses to widespread impacts were highlighted. We have found that some drivers are well studied, but we need to collect more detailed and longer‐term data on species requirements and on the impacts that bird populations face to devise priorities for conservation action and research for mountain and upland birds.

Benefits of playa buffers as bird habitat

Playa wetlands are important for maintaining biodiversity in otherwise nondiverse landscapes in the High Plains of the western Great Plains. Vegetation buffers around playas have been documented to reduce runoff of sediments and contaminants; however, there have been few assessments of the effects of buffers on bird communities. I conducted point counts during the breeding season and sampled vegetation at playa buffer sites and control playas to assess effects of buffers on breeding birds and their habitat. Relative abundance of wetland-dependent birds and total birds was substantially greater at buffered playas than unbuffered playas. I was not able to detect a difference in upland bird relative abundance between treatments. This was likely due to the habitat requirements of the most frequently detected upland birds: Common Grackle (Quiscalus quiscula) and Horned Lark (Eremophila alpestris). Buffered playas contained more visual obstruction and percent forb cover than control playas, but I was unable to detect a difference in percent grass or bare ground. Overall, playa buffers supported more birds and provided better habitat conditions for many bird species than unbuffered sites, and I suggest further research examining survival and reproductive output of birds using playa buffers.

Economics of the Conservation Reserve Program and the wildlife it supports: A case study of upland birds in South Dakota

The research presented in this study focuses on the economic value of the U.S. Department of Agriculture's Conservation Reserve Program (CRP) by using primary survey data to derive both the economic contribution (jobs, wages, and value-added) and consumer welfare values. The combination of the two economic methods as it pertains to the CRP is a novel approach within the published literature. The survey was conducted querying upland bird hunters in South Dakota on their hunting activities, expenditures, and use of land enrolled in the CRP. In 2013, South Dakota had 972,000 acres enrolled in the CRP and have consistently ranked in the top ten for states with enrolled acres. Based on the data gathered and 2015 hunter figures, our results indicate that upland bird hunting on CRP lands contributed $17.7 million of annual value added and 365 jobs to the state economy. Furthermore, our study estimates consumer surplus benefits of $133.7 million annually to South Dakota upland game bird hunters are associated with CRP lands. Although elected officials often concentrate on economic contribution and/or impacts, one should not overlook welfare values as they are a measure of well-being—something pertinent to rural areas of the U.S. that struggle with outmigration and attracting new employment opportunities. The collective results within this study highlight the economic importance of the CRP to the outdoor recreation sector. Given these economic impacts capture only a portion of CRP benefits, they indicate large potential economic impacts to the South Dakota economy if a large reduction in program acres were to occur.

Lead concentration in game migratory upland bird meat: Influence of ammunition impacts and health risk assessment

Consumption of Pb-contaminated game meat is a concern for the population, as it poses a potential risk to consumer health. Thus, this study is aimed at determining Pb content in muscle tissue of migratory birds, evaluating the influence of the use of Pb ammunition on the content of this element in migratory upland game bird meat, and estimating the health risk arising from consumption thereof. Breast muscle of common woodpigeon (Columba palumbus) (n = 27), European turtle-dove (Streptopelia turtur) (n = 21) and song thrush (Turdus philomelos) (n = 35) were analyzed. Pb concentrations in breast muscle were 3.4; 0.98 and 0.82 mg/kg ww in common woodpigeon, European turtle-dove and song thrush, respectively. Risk assessment was performed using a benchmark dose, and margin of exposure (MOE) and plug in estimator (PI) were calculated. The estimated mean and 95th percentile Pb-intake for an extreme consumption (90 meals per year) werepar 0.045–0.079 and 0.083–0.14 μg/kg bw per day for adult and child consumers, respectively. Risk assessment showed that consumption of meat from common woodpigeon, European turtle-dove and song thrush hunted using traditional hunting methods for these species in Spain does not pose a significant health risk to adult and child consumers. Nonetheless, a particularly high risk occurs when animals carry excessive Pb concentrations, i.e. when they show a high number of impacts, in which case they would not be suitable for consumption and would need to be discarded. Future research is required to further improve the food safety of game meat in the domestic environment of hunters and their households, who are the primary consumers of this type of meat.

Can microclimate offer refuge to an upland bird species under climate change?

Climate change is a severe threat to biodiversity. Areas with a high variety of microclimates may provide opportunities for species to persist in a changing climate. Test the extent to which microclimate is an important determinant of the distribution of a widespread upland passerine, the meadow pipit Anthus pratensis, and whether microclimate becomes an increasingly important determinant of distribution towards the warm edge of the species’ range. We used models of the occurrence of meadow pipits based on data from an extensive survey to identify macroclimate and topographic associations, the latter as proxies of microclimate. We assessed magnitude and direction of the effects of microclimate and whether the magnitude of microclimate effects increases as macroclimate suitability declines. The probability of meadow pipit occurrence is significantly correlated with macroclimate and microclimate. Microclimate accounts for about a third of the variation in occupancy probability and has a stronger effect than macroclimate at all three spatial scales considered. Elevation and topographical wetness index are positively correlated with meadow pipit occurrence, while insolation is negatively correlated. Elevation and macroclimate suitability show a positive interaction, while insolation and macroclimate suitability show a negative interaction. Microclimate substantially influences the distribution of the meadow pipit. For high latitude and upland species such as this, suitable areas on cool slopes could form the focus for conservation protection, as these areas are likely to become increasingly utilised and may remain the only locations occupied in otherwise unsuitable climate.

Livestock grazing impacts components of the breeding productivity of a common upland insectivorous passerine: Results from a long‐term experiment

Abstract The intensity of pastoral management in areas of High Nature Value farming is declining in some regions of Europe but increasing in others. This affects open habitats of conservation concern, such as the British uplands, where bird species that benefit from low‐intensity grazing may be most sensitive to such polarization. While experimental manipulations of livestock grazing intensities have improved our understanding of upland breeding bird responses in the short term, none have examined the long‐term impacts of altered management on reproductive success. Using a replicated landscape‐scale experiment that started in 2003, we investigated the effects of four grazing treatments (intensive sheep; low‐intensity sheep; low‐intensity mixed sheep and cattle; and no grazing) on the breeding productivity of meadow pipits Anthus pratensis, the most common upland passerine. Surveys were carried out systematically during early (2003 and 2004) and late (2015 and 2016) sampling periods of the experiment to compare the short‐ and long‐term effects of grazing treatments on breeding density and productivity of pipits specifically, but also on the overall bird community. Pipit breeding density was lowest under low‐intensity sheep grazing while the highest egg‐stage nest survival was observed in the same treatment, although no significant treatment effects were detected on overall nest survival or fledgling output. There were no significant differences in treatment effects between the sampling periods on any breeding variable, but overall nest survival was lower in the later sampling period across all treatments. Breeding bird species richness differed between treatments in the later sampling period, with highest species richness in the ungrazed treatment. Synthesis and applications. Livestock grazing management can have different outcomes for different upland birds. Our results showed that, with time, meadow pipit breeding productivity tended to be higher when sheep grazing intensity was reduced and/or mixed with cattle, and lower when livestock were removed, but not significantly so. Removal of grazing, however, can significantly increase bird species richness. The long‐term experiment showed an overall decline in fledglings regardless of grazing treatments, potentially a result of increased predator numbers harboured by nearby developing woodland, highlighting the importance of considering wider landscape processes in grazing management decisions.

Incubation recess behaviors influence nest survival of Wild Turkeys.

In ground nesting upland birds, reproductive activities contribute to elevated predation risk, so females presumably use multiple strategies to ensure nest success. Identification of drivers reducing predation risk has primarily focused on evaluating vegetative conditions at nest sites, but behavioral decisions manifested through movements during incubation may be additional drivers of nest survival. However, our understanding of how movements during incubation impact nest survival is limited for most ground nesting birds. Using GPS data collected from female Eastern Wild Turkeys (n = 206), we evaluated nest survival as it relates to movement behaviors during incubation, including recess frequency, distance traveled during recesses, and habitat selection during recess movements. We identified 9,361 movements off nests and 6,529 recess events based on approximately 62,065 hr of incubation data, and estimated mean nest attentiveness of 84.0%. The numbers of recesses taken daily were variable across females (range: 1‒7). Nest survival modeling indicated that increased cumulative distance moved during recesses each day was the primary driver of positive daily nest survival. Our results suggest behavioral decisions are influencing trade‐offs between nest survival and adult female survival during incubation to reduce predation risk, specifically through adjustments to distances traveled during recesses.

Spatial gradients in country‐level population trends of European birds

AbstractAimPopulation trends reflect influence of environmental drivers acting upon species' population dynamics. As the strength of this influence may change predictably in space, we test multiple hypotheses about spatial gradients in the effects of environmental drivers on bird population trends across the continent.LocationEurope.MethodsWe used country‐level population trends for 249 bird species in 32 European countries. For each species, we expressed values of 12 traits which mirror the influence of major environmental drivers: climate change, land‐use change and change in environmental legislation. We related these traits to population trends using generalized additive mixed models and tested for the presence of spatial gradients by including the interaction of countries' geographic position with four of these traits for which we hypothesized spatial patterns in relationships to trends.ResultsSpecies listed for the longest time under Annex I of the EU's Birds Directive had increasingly positive trends towards the north‐west, but an indication of the opposite pattern was found for shorter‐listed species. Cold‐adapted species had increasingly negative trends towards the North and especially the north‐west, whereas the trends of the warm‐adapted species were generally positive and increased in northern direction. Spatial gradients in trends were weaker for the habitat niche position with forest species having positive trends in North‐Eastern Europe and open‐habitat species having negative trends in the Westernmost edge of the continent.Main conclusionsThe influence of all major hypothesized drivers varies across Europe. Climate change impacts are probably most detrimental in North‐Western Europe for the Arctic and upland birds, whereas the warm‐adapted species may benefit from these changes at the same time. The differences in the enforcement of environmental legislation among countries are a likely driver of the spatial patterns for the Annex I species, whereas the unification of land‐use intensity may be the cause of relatively weak patterns in the habitat niche effects.

Exploring relationships between land use intensity, habitat heterogeneity and biodiversity to identify and monitor areas of High Nature Value farming

Understanding how species richness is distributed across landscapes and which variables may be used as predictors is important for spatially targeting management interventions. This study uses finely resolved data over a large geographical area to explore relationships between land-use intensity, habitat heterogeneity and species richness of multiple taxa. It aims to identify surrogate landscape metrics, valid for a range of taxa, which can be used to map and monitor High Nature Value farmland (HNV).Results show that variation in species richness is distributed along two axes: land-use intensity and habitat heterogeneity. At low intensity land-use, species rich groups include wetland plants, plant habitat indicators, upland birds and rare invertebrates, whilst richness of other species groups (farmland birds, butterflies, bees) was associated with higher land-use intensity. Habitat heterogeneity (broadleaved woodland connectivity, hedgerows, habitat diversity) was positively related to species richness of many taxa, both generalists (plants, butterflies, bees) and specialists (rare birds, woodland birds, plants, butterflies).The results were used to create maps of HNV farmland. The proportion of semi-natural vegetation is a useful metric for identifying HNV type 1. HNV type 2 (defined as a mosaic of low-intensity habitats and structural elements) is more difficult to predict from surrogate variables, due to complex relationships between biodiversity and habitat heterogeneity and inadequacies of current remotely sensed data.This approach, using fine-scaled field survey data collected at regular intervals, in conjunction with remotely sensed data offers potential for extrapolating modelled results nationally, and importantly, can be used to assess change over time.

Effects of development of wind energy and associated changes in land use on bird densities in upland areas.

Wind energy development is the most recent of many pressures on upland bird communities and their habitats. Studies of birds in relation to wind energy development have focused on effects of direct mortality, but the importance of indirect effects (e.g., displacement, habitat loss) on avian community diversity and stability is increasingly being recognized. We used a control-impact study in combination with a gradient design to assess the effects of wind farms on upland bird densities and on bird species grouped by habitat association (forest and open-habitat species). We conducted 506 point count surveys at 12 wind-farm and 12 control sites in Ireland during 2 breeding seasons (2012 and 2013). Total bird densities were lower at wind farms than at control sites, and the greatest differences occurred close to turbines. Densities of forest species were significantly lower within 100 m of turbines than at greater distances, and this difference was mediated by habitat modifications associated with wind-farm development. In particular, reductions in forest cover adjacent to turbines was linked to the observed decrease in densities of forest species. Open-habitat species' densities were lower at wind farms but were not related to distance from turbines and were negatively related to size of the wind farm. This suggests that, for these species, wind-farm effects may occur at a landscape scale. Our findings indicate that the scale and intensity of the displacement effects of wind farms on upland birds depends on bird species' habitat associations and that the observed effects are mediated by changes in land use associated with wind-farm construction. This highlights the importance of construction effects and siting of turbines, tracks, and other infrastructure in understanding the impacts of wind farms on biodiversity.

Are Boreal Riparian Bird Communities Unique? Contrasting Riparian and Upland Bird Assemblages in the Boreal Plain of Western Canada

Riparian ecotones in arid regions often contain unique species and have higher species richness and abundance relative to upland habitats making them of higher conservation priority than other habitats. However, such differences in species richness and abundance may not be apparent in more mesic regions. We compared species frequency of occurrence and abundance, richness and turnover of bird assemblages in two aquatic ecotone types with those in nearby interior upland forests in the boreal forest of Alberta, Canada. Riparian edge habitats had higher species richness and more species with significant indicator values than lowland forest edge or interior upland forest and the greatest differences in bird community composition were between riparian edge and upland interio habitats. Species turnover was highest in riparian habitats attributable to the presence of rare species or higher spatial and structural heterogeneity of those systems. When contrasting the upland forested area adjacent to the waterbody versus a similar sized area in the upland forest interior, riparian areas still contained higher richness but had fewer indicator species. We suggest that riparian areas and the adjacent shoreline forest contribute considerably to the regional richness of bird communities in the boreal forest and management policies should reflect this characteristic.

A review and meta‐analysis of the effects of climate change on Holarctic mountain and upland bird populations

Mountain regions are globally important areas for biodiversity but are subject to multiple human‐induced threats, including climate change, which has been more severe at higher elevations. We reviewed evidence for impacts of climate change on Holarctic mountain bird populations in terms of physiology, phenology, trophic interactions, demography and observed and projected distribution shifts, including effects of other factors that interact with climate change. We developed an objective classification of high‐elevation, mountain specialist and generalist species, based on the proportion of their breeding range occurring in mountain regions. Our review found evidence of responses of mountain bird populations to climate (extreme weather events, temperature, rainfall and snow) and environmental (i.e. land use) change, but we know little about either the underlying mechanisms or the synergistic effects of climate and land use. Long‐term studies assessing reproductive success or survival of mountain birds in relation to climate change were rare. Few studies have considered shifts in elevational distribution over time and a meta‐analysis did not find a consistent direction in elevation change. A meta‐analysis carried out on future projections of distribution shifts suggested that birds whose breeding distributions are largely restricted to mountains are likely to be more negatively impacted than other species. Adaptation responses to climate change rely mostly on managing and extending current protected areas for both species already present, and for expected colonizing species that are losing habitat and climate space at lower elevation. However, developing effective management actions requires an improvement in the current knowledge of mountain species ecology, in the quality of climate data and in understanding the role of interacting factors. Furthermore, the evidence was mostly based on widespread species rather than mountain specialists. Scientists should provide valuable tools to assess the status of mountain birds, for example through the development of a mountain bird population index, and policy‐makers should influence legislation to develop efficient agri‐environment schemes and forestry practices for mountain birds, as well as to regulate leisure activities at higher elevations.

Quantifying the importance of multi‐scale management and environmental variables on moorland bird abundance

UK moorlands are semi‐natural habitats managed for a mix of livestock, game shooting and forestry, among other activities. An assessment of the importance of characteristics that correlate with moorland bird populations of high conservation importance can inform appropriate management at appropriate locations. We use hierarchical partitioning to assess the absolute and relative importance of climate, topography, soil, landscape management (wider scale habitat configuration of forestry and agriculture) and site‐based management (indices of predator control, and vegetation characteristics) in determining the abundance of a suite of upland birds in four regions of the UK. Unmeasured region‐specific effects often made the largest contribution to models. Physical characteristics (climate, topography, soil) were important and on average explained a similar amount of variation to site‐based management. However, there was considerable interspecific variation in the importance of both. Landscape‐scale variables were generally of low importance. An index of predator control was positively correlated with the abundance of Red Grouse Lagopus lagopus scotica and two waders. Vegetation characteristics (composition and structure) were, together, strong correlates of the abundance of passerine species. Vegetation characteristics were as important as indices of predator control for waders and grouse. The importance of regional effects, physical characteristics and variables relating to management suggest targeting site‐based management (such as predator control or vegetation management) to the areas where physical characteristics are most favourable. The most beneficial management will vary between species, necessitating a mosaic of management options across upland areas to benefit all species.

Changes in upland bird abundances show associations with moorland management

ABSTRACTCapsule: Changes in abundance of six bird species showed associations with moorland management.Aims: To assess responses of breeding birds to moorland management over a 14-year period.Methods: Vegetation and birds were surveyed at 2–3-year intervals and changes examined in relation to sheep and cattle grazing, vegetation burning and cutting.Results: Seven correlations between change in management and change in bird abundance were detected, and six between change in vegetation and change in bird abundance. On plots where sheep numbers declined, Golden Plover Pluvialis apricaria and Northern Wheatear Oenanthe oenanthe declined. Where a greater area was burned, Golden Plover increased in the initial post-burning period but Red Grouse Lagopus lagopus scotica declined. Eurasian Curlew Numenius arquata and Sky Lark Alauda arvensis increased where a greater area of moorland vegetation was cut. Whinchat Saxicola rubetra declined with increasing cattle numbers on a plot.Conclusions: Bird populations respond to changes in moorland management, but these changes are not always associated with detectable changes in vegetation. These responses of moorland breeding birds to management could help refine agri-environment options and other conservation interventions on moorland. Responses differed between bird species, ideally requiring site-specific planning where managing for multiple species is a goal.

Should topographic metrics be considered when predicting species density of birds on a large geographical scale? A case of Random Forest approach

Species Distribution Modelling (SDM) is a group of statistical tools that describe species distribution in environmental gradients in order to create their predictive distribution. However, due to the complexity of factors that influence the occurrence or density of species these methods’ effectiveness is still debatable. That is why we decided to explore how topographic metrics, such as altitude, slope, roughness and aspect, would affect the density of farmland (Icterine warbler) and forest (Eurasian golden oriole) bird species. We generated two sets of SDMs for each of the two bird species: One set of models contained topographic metrics as a predictor variable, and the other did not. Out-of-back procedures in the Random Forest approach and evaluation models based on independent dataset scores showed that omitting topographic metrics as predictors resulted in a substantial reduction of model performance for both lowland and upland bird species. Further analysis of predictive maps revealed that neglecting topographic metrics resulted in large over-predictions of species’ densities in regions where these species were rare. Importantly, our results also support the notion that detailed topographic metrics can be considered as a surrogate for elusive climatic factors and the habitat’s condition. Hence, the study emphasises that the process of selecting predictor variables, especially topographic metrics, is one of key elements in developing Species Distribution Models for birds, even for those species which are not directly dependant on the topographic metrics.

Ontario Ministry of Natural Resources South-Central Region Bobwhite Quail Rehabilitation Program

Archaeological and historical evidence on status of northern bobwhites (Colinus virginianus) in southern Ontario prior to European settlement is not clear. The bird was documented on the Essex and Kent County prairies at the time of European settlement in the early l700's. Early farmsteading increased available habitat space for quail. That landscape, combined with mild winters in the l 840's, enabled bobwhites to expand their ranges. By the mid-l 850's, bobwhites ranged generally throughout Ontario's tallgrass prairie and savannah communities extending from the Detroit River approximately 300 miles north into Simcoe County, the southeast limit of Georgian Bay, and 400 miles east to Kingston, the eastern limit of Lake Ontario. Bobwhites became a valued upland bird in pioneer Ontario for hunting, viewing and controlling farm garden weed seeds and insects. The detrimental impacts of harsh winters were a major contributor to quail declines from the late l 850's to the l 980's. Additionally, more subtle factors which also contributed detrimental stresses were loss of tallgrass prairie and savannah, intensive agriculture, continued deforestation, urbanization, pesticide use, the taking of wild stock for pen-rearing and the low survival rates of introduced cultured stocks into the wild. In summary, bobwhites in Ontario declined due to the destruction, impairment and fragmentation of wildlife habitat. The population stabilized at low numbers during the early l 980's. Recreational harvesting of the species continued into the l 970's. Gun harvests probably at no time exerted a controlling influence on the quail populations. The harvest diminished to non-existence in the 1980's. The hunting seasons for wild populations were eliminated in the l 990's. People continued to appreciate the bird for recreational viewing and dog training opportunities. In spite of agricultural trends towards less intensive land uses, new emphases on resource and environmental conservation and rehabilitation, as well as milder winters in the l 980's and l 990's, bobwhite numbers have not rebounded in southwest Ontario. Approximately 185 birds in 16 coveys throughout Elgin, Lambton and Middlesex counties were documented in 1990. Although large areas of suitable land are unoccupied by bobwhites, populations remain small, disjunct and isolated. Ontario Ministry of Natural Resources formed partnerships with a number of other governmental agencies, non-governmental organizations and landowners, to initiate the rehabilitation of bobwhite quail in southern Ontario. The Ontario Federation of Anglers and Hunters, their affiliate and individual members, are a key sponsor to this rehabilitation initiative. These groups have participated in an advisory committee, raised funds, and offered volunteer labor, predator control services adjacent to release sites, and professional services. The committee recommended the transfer of wild bobwhites from other North American populations as a means of rehabilitating Ontario populations. The program's goal is to reestablish larger, sustainable populations of quail in southern Ontario to provide recreational viewing and hunting opportunities. It is anticipated that large numbers of urban and rural Ontarians will be pleased with the reestablishment of northern bobwhites and the recreational viewing and hunting benefits they provide. Restoration of quail hunting opportunities will generate economic benefits in Ontario and may be a suitable method for monitoring the grass-shrubland ecotone. Healthy quail populations also have the potential to function as natural control agents for some crop pests.