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Understanding the links between breeding and wintering areas of migratory species has important ecological and conservation implications. Recently, stable isotope technology has been used to further our understanding. Stable isotope ratios vary geographically with a range of biogeochemical factors and isotope profiles in organisms reflect those in their food and environment. For inert tissues like feathers, isotope profiles reflect the environment in which they were formed. Following large-scale habitat destruction, the globally threatened aquatic warbler Acrocephalus paludicola has a fragmented breeding population across central Europe, largely in Belarus, Poland and Ukraine. The species' sub-Saharan African wintering grounds have not yet been discovered, and this significantly hampers conservation efforts. Aquatic warblers grow their flight feathers on their wintering grounds, and we analysed stable isotope ratios (delta(15)N, delta(13)C, delta D) in rectrices of adults from six main breeding sites (subpopulations) across Europe to determine whether different breeding subpopulations formed a single mixed population on the wintering grounds. delta(15)N varies considerably with dietary trophic level and environmental factors, and delta D with the delta D in rainfall; neither varied between aquatic warbler subpopulations. Uniform feather delta(15)N signatures suggest no major variation in dietary trophic level during feather formation. High variance and inter-annual differences in mean delta D values hinder interpretation of these data. Significant differences in mean delta(13)C ratios existed between subpopulations. We discuss possible interpretations of this result, and consider differences in moulting latitude of different subpopulations to be the most parsimonious. delta(13)C in plants and animals decreases with latitude, along a steep gradient in sub-Saharan Africa. Birds from the most northwesterly breeding subpopulation (Karsibor, Poland) had significantly lower variance in delta(13)C and delta(15)N than birds from all other sites, suggesting either that birds from Karsibor are less geographically dispersed during moult, or moult in an area with less isotopic heterogeneity. Mean delta(13)C signatures from winter-grown feathers of different subpopulations were positively correlated with the latitude and longitude of breeding sites, suggesting a strong relationship between European breeding and African winter moulting latitudes. The use of stable isotopes provides novel insights into migratory connectivity and migration patterns in this little-known threatened species.

Weather conditions during the early life of precocial chicks of some bird species have marked effects on survival and may also cause changes in adult population size. In this paper, we use data from broods with radiotagged mothers to examine correlations of growth rates and survival of Corncrake Crex crex chicks in Scotland and Ireland with temperature and rainfall. The loss of whole broods before they reached independence was infrequent and not correlated with temperature or rainfall. Loss of some chicks from broods before independence usually occurred and multiple regression analysis indicated that the proportion of chicks that survived increased with decreasing initial brood size, increasing temperature and decreasing rainfall. However, the magnitude of the effects of weather on survival were quite small. The rate of weight gain of chicks varied considerably within and among broods. The mean daily weight gain rate of broods decreased significantly with increasing rainfall, and variation in the weight of chicks within broods was greater for broods whose mean rate of weight gain was low.

Most attempts to quantify the impact of humanity on nature and bring it to public attention have centred around estimates of extinction rates. Suggestions that these figures have been exaggerated are, in our view, misplaced, but extinction rate estimates do face other problems – inevitable uncertainty, an arguably weak link to economic value, and insensitivity to short-term change. We therefore look here at other large-scale measures of the changing state of nature, focusing on recent analyses of trends in population size, numbers of populations and habitat extent. In spite of being limited by sampling inadequacies, these data provide a sensitive short-term complement to the long-term perspective gained from considering extinction rates that can be linked directly both to economic values and to public concerns. Although further work is needed on extinction rates, we conclude that significant new emphasis should be placed on instituting broader, more systematic monitoring of habitats and populations.

The Ministerial Declaration made at the World Summit on Sustainable Development in Johannesburg agreed to protection and restoration of the integrity of our planet's ecological systems and identified as a major priority a significant reduction in the rate of current biodiversity loss at national and global levels. This goal is essentially a reformulation of that of the Convention on Biological Diversity agreed to in Rio de Janeiro 10 years ago. For us to have any idea of where we are in relation to this goal, we need information on current global trends in the status of natural systems. By 2005 it is envisaged that the Millennium Ecosystem Assessment (MA) will have provided a comprehensive account of global biodiversity from a compilation of existing data, but that is a long time to wait. What can we say now about trends in the state of wild nature since the United Nations' 1992 Conference on Environment and Development in Rio de Janeiro? Here, we briefly review recent global trends in habitat area in as many broadly defined natural habitats as possible and in indices of animal populations characteristic of those habitats. The information available indicates continuing declines in habitat area and species, but that data are extremely sparse.

Jerdon's courser Rhinoptilus bitorquatus is a nocturnal cursorial bird that is now only known from a small area of scrub jungle in Andhra Pradesh, India. Its population size, distribution and habitat requirements are poorly known because of its elusive habits. We conducted a trial of a survey method that involved deploying an array of 5 m long tracking strips consisting of smoothed fine soil, and checking them for footprints at regular intervals. We developed diagnostic methods for distinguishing the footprints of Jerdon's courser from those of other species. Tracks of Jerdon's courser were obtained on about one strip-night in 30 from areas where the species was known to be present. We suggest a procedure for using tracking strips to survey areas where Jerdon's courser has not yet been detected. The use of tracking strips carries a small risk of misidentification of footprints of other species, especially yellow-wattled lapwing Vanellus malarbaricus, as those of Jerdon's courser, but has the advantage that large areas can be surveyed without the use of expensive equipment or night-time fieldwork. We recommend the use of automatic camera traps to obtain confirmation of records of probable Jerdon's courser footprints.

Veterinary use of the non-steroidal anti-inflammatory drug diclofenac on domesticated ungulates caused populations of resident Gyps vultures in the Indian sub-continent to collapse. The birds died when they fed on carrion from treated animals. Veterinary diclofenac was banned in 2006 and meloxicam was advocated as a ‘vulture-safe’ alternative. We examine the effectiveness of the 2006 ban, whether meloxicam has replaced diclofenac, and the impact of these changes on vultures. Drug residue data from liver samples collected from ungulate carcasses in India since 2004 demonstrate that the prevalence of diclofenac in carcasses in 2009 was half of that before the ban and meloxicam prevalence increased by 44%. The expected vulture death rate from diclofenac per meal in 2009 was one-third of that before the ban. Surveys at veterinary clinics show that diclofenac use in India began in 1994, coinciding with the onset of rapid Gyps declines ascertained from measured rates of declines. Our study shows that one pharmaceutical product has had a devastating impact on Asia's vultures. Large-scale research and survey were needed to detect, diagnose and quantify the problem and measure the response to remedial actions. Given these difficulties, other effects of pharmaceuticals in the environment may remain undetected.

Introduction So far in this book we have described the mechanisms by which climate change affects birds, reviewed potential future changes in their distribution and abundance caused by climate change and discussed the implications of these for conservation. It is clear that as the magnitude of warming increases, so will the likely severity of impacts on bird populations. The number of projected bird extinctions is modelled to increase by about 1.6 times from a 2 °C to 4 °C global warming scenario, and differ by approximately 2.5 times between a 2 °C and 6 °C scenario (Box 6.5), when it is estimated one-quarter of global bird species would be at risk of being committed to extinction as a result of climate change (Section 6.8.2). Clearly, addressing the causes of climate change will be an important way of reducing the likely detrimental impacts of climate warming on birds (Warren et al . 2013). However, attempts to do this through the reduction of greenhouse gas emissions or the removal of gases from the atmosphere (termed climate change mitigation) may also have a detrimental effect on bird populations. The principal sources of anthropogenic greenhouse gas emissions are carbon dioxide from the burning of fossil fuels (coal, oil and gas), deforestation and other land use changes leading to the burning or decay of plant material, release of methane from refuse in landfill sites, gut fermentation by ruminant livestock and the farming of rice, and release of nitrous oxide caused by the use of fertilizers in agriculture (Section 1.5). Changes in the ways in which energy is obtained and used, the protection of forests and peatlands and changes in farming practice are therefore the main methods being considered for climate change mitigation. In addition, there might be ways in which the environment could be artificially adapted to remove greenhouse gases from the atmosphere at higher rates. All of these mitigation measures will change the natural environment and could therefore affect bird populations. In this chapter we examine some of these potential effects and assess ways in which potential adverse impacts of mitigation may be reduced, focussing particularly on renewable energy generation.

Increasing agricultural productivity to ‘close yield gaps’ creates both perils and possibilities for biodiversity conservation. Yield increases often have negative impacts on species within farmland, but at the same time could potentially make it more feasible to minimize further cropland expansion into natural habitats. We combine global data on yield gaps, projected future production of maize, rice and wheat, the distributions of birds and their estimated sensitivity to changes in crop yields to map where it might be most beneficial for bird conservation to close yield gaps as part of a land-sparing strategy, and where doing so might be most damaging. Closing yield gaps to attainable levels to meet projected demand in 2050 could potentially help spare an area equivalent to that of the Indian subcontinent. Increasing yields this much on existing farmland would inevitably reduce its biodiversity, and therefore we advocate efforts both to constrain further increases in global food demand, and to identify the least harmful ways of increasing yields. The land-sparing potential of closing yield gaps will not be realized without specific mechanisms to link yield increases to habitat protection (and restoration), and therefore we suggest that conservationists, farmers, crop scientists and policy-makers collaborate to explore promising mechanisms.

Science and Regulation., An estimated 6051 tons of active substances went into the production of veterinary pharmaceuticals (VPs) for the treatment of food animals in the European Union (EU) in 2004, including 5393 tons of antibiotics and 194 tons of antiparasitics. With global meat production projected to increase and the growing market for companion animal pharmaceuticals, the use of VPs will continue to increase. Although VPs may benefit the health and welfare of domestic animals and the efficiency of food animal production, they can contaminate the environment through manufacturing, treatment of animals, and disposal of carcasses, offal, urine, feces, and unused products (see the chart). This contamination is a threat to nontarget species, including humans. With Spain having recently authorized marketing of a VP that was banned in South Asia in the past decade in light of environmental impacts, we recommend strengthening of current procedures and addition of a more proactive, holistic, One Health approach applicable to all VPs., A.M. was supported by a Ramón y Cajal research contract from the Ministerio de Economía y Competitividad (RYC-2012-11867). J.A.D. andJ.A.S.-Z.were supported by projects CGL2012- 40013-CO2-01-02 and RNM1925.

The shapes of the tips of Corncrake Crex crex secondary remiges grown by chicks and adults were compared. Measurements of secondaries of birds of known age were obtained from wild Corncrakes in Britain and captive‐bred birds originating from Germany and Poland. The tips of secondaries grown in the hatching year were more pointed than those grown in subsequent years in both samples. Secondaries grown in the hatching year are retained until the autumn of the next calendar year. Consequently the average shape of the tips of secondaries of one year old adults was different from that of older birds. The sum of the angles measured at the tips of secondaries 3 to 6 inclusive (numbered ascendantly) was used to quantify this difference. The angle sum scores of known first‐years and older birds overlapped, but it is possible to estimate the proportions of the two age classes in a sample of adults of unknown age by assuming that the distribution of scores is the combination of two normal distributions with means and...

Summary 1 Breeding birds, vegetation and moorland management were surveyed in 320 1-km squares on 122 estates in upland areas of eastern Scotland and northern England where red grouse shooting is a widespread land use. We assessed whether population densities of 11 species of breeding birds differed between heather-dominated moorland managed for red grouse shooting and other moorland with similar vegetation. 2 We classified estates that had a full-time equivalent moorland gamekeeper as grouse moors. The mean density of red grouse shot per year was four times higher and the mean density of gamekeepers was three times higher on grouse moors than on other moors. Rotational burning of ground vegetation covered a 34% larger area on grouse moors than on other moors. 3 Selection of heather-dominated squares resulted in similar composition of vegetation on grouse moors and other moors (about 76% heath, 12% grass, 8% bog, 2% flush and

A census of Corncrakes throughout Britain was carried out in 1998. National Grid squares of 10 km in the Hebrides, Northern Isles and the mainland of Highland Scotland known to have held the species during the breeding season since 1988 were searched systematically by night for singing males. A sample of such squares elsewhere in Scotland was also searched. In addition, bird-watchers and the general public were encouraged by press publicity to contribute records of singing birds, which were checked for accuracy. A total of 589 singing males was counted in 93 10-km squares. Ninety percent of the population was in the Hebridean Islands. The total count was 23% larger than in the previous census in 1993 and 3% larger than in 1988. All surveys of distribution and censuses between the late 19th century and 1993 recorded a progressive decline in the national population and range. The average rate of population decline between 1988 and 1993 was 3.5% per year, but between 1993 and 1998 the population increased by...

Populations of waders (Charadrii) on machair habitats on the island of South Uist were counted and wader nests were monitored to determine nest success and causes of failure. There were large declines in wader numbers and nest success following the spread of the introduced hedgehog throughout the island. Predation of wader eggs by hedgehogs was frequent, but susceptibility varied among wader species, being between 0 and 60% of the nests started. Wader species that were susceptible to hedgehog predation tended to suffer larger population declines than those that were less susceptible, with the exception that the ringed plover (Charadrius hiaticula) population declined markedly even though their nests were depredated by hedgehogs infrequently. A combined analysis of mark-resighting and radio-tracking data produced an average hedgehog population density estimate of 57 adults km−2. It was estimated that wader eggs only provided 0.7–5.5% of the energy requirements of hedgehogs, even during the season when most eggs were taken. From this it is argued that the abundance of hedgehogs and the intensity of their predation on wader eggs are unlikely to diminish in response to wader population declines. Unless some presently unidentified density-dependent mechanism compensates for low nest success, local extinctions of susceptible wader species are likely if no action is taken to reduce hedgehog predation. This appears to be the first documented case of hedgehogs threatening an internationally important bird population with regional extinction.

Distribution, habitat use and selection, ranging behaviour, diet and food supply of the stone curlew Burhinus oedicnemus were studied in a small, fragmented population at the north-western edge of its world range. Stone curlews bred on short semi-natural grassland and spring-sown arable farmland in areas with sandy soils with stones or rubble. They were most active at night and travelled up to about 3 km from the nest to forage. Individuals used a fragmented home range comprising an average of 30 ha of short semi-natural grassland, short improved pasture and spring-sown crops for foraging. Earthworms, soil-surface arthropods and molluscs were the main prey; the proportion of earthworms being lowest when the soil was dry. Breeding densities were highest on short semi-natural grassland. Stone curlews were most likely to breed on a spring-sown arable field if the crop was of a type that became tall and dense relatively late in the summer and if the field was close to short semi-natural grassland or sheep pasture and distant (> 3 km) from the nearest major road. Sparse vegetation and bare ground were the most obvious characteristics of habitats preferred for nesting and foraging.

Methods for diagnosing the causes of bird population declines are described. Special attention is paid to methods which rely on comparisons across geographical regions and/or time periods with different population trends. Comparisons of breeding success and survival across regions or periods provide a valuable check on the diagnosis of the causes of a decline determined by correlation of population trends with candidate causal external factors. Ringing can provide information on population levels and is the main source of information on survival. Age ratios of trapped birds and catches of juveniles and adults in standardised trapping programmes can provide data on breeding success. The latter information complements residts from nest recording because it reflects season‐long breeding success, rather than success per breeding attempt. Morphometric measurements of trapped birds also have potential uses for the assessment of breeding success. The computerisation of ringing information, as well as of recoveri...

1. This strategy aims to increase the contribution which ringing makes to conservation science and ornithological research, recognising that the primary outputs of the scheme are scientific publications based on data gathered by volunteer ringers. The strategy envisages a greater involvement of ringers in planned projects that are designed to provide specific types of information. Clear advice on priority species and categories of birds (eg age classes, seasons of ringing, breeding vs roosting) to be ringed and recaptured will be given to those ringing outside centrally organised projects. 2. The research programme will focus on two main topics, population dynamics and migration and movements. In addition research on life‐histories, moult and condition should be conducted when opportunities allow. 3. The Ringing Scheme makes a vital contribution to studies of population dynamics by providing data on survival rates and productivity, and sometimes also on numbers. Popidation dynamics models based on such da...

Summary 1. A recent analysis showed that the survival and breeding success of female hen harriers were much lower on grouse moors than on other upland land management classes in Scotland, excluding the Orkney islands: a difference attributed to persecution of hen harriers by humans on grouse moors. However, this study did not look for possible beneficial effects on hen harrier breeding success of the control by moorland gamekeepers of other predators, particularly red foxes. 2. These and other recently published data were re-examined to see whether there was regional variation in hen harrier nest success associated with the presence or absence of foxes and the control of foxes and other predators by moorland gamekeepers. 3. The main finding of the previous analysis, that nest success was much lower on grouse moors than on moorland that was not managed for grouse or in young conifer forests, was even more striking when comparisons were made among land management classes within the same region. 4. The mean number of broods fledged per female hen harrier per year on two grouse moors at which gamekeepers prevented human interference with harrier nests and continued to control other predators was compared with the average for moorland in Scotland. Harrier productivity on these moors was much higher than the average for grouse moors, but similar to the average for moorland not managed for grouse shooting. 5. Nest success of hen harriers breeding on moorland not managed for grouse averaged 19% higher in regions where there were, on average, more grouse moors in the vicinity, but in young conifer forests success was 34% lower in regions with more grouse moors nearby. Neither of these differences was statistically significant. 6. Nest success within a particular land management class was not significantly different inside and outside the range of the red fox. 7. Even a generous assessment of the magnitude of a supposed beneficial effect of the control of foxes and other predators by moorland gamekeepers on hen harrier nest success indicated that its effect on the population trend of hen harriers would be small relative to the large negative effect of persecution of harriers on grouse moors.

The numbers and breeding success of the Stone Curlew Burhinus oedicnemus, a rare bird in the UK, were studied on chalk downland at Porton Down, Wiltshire, from 1987 to 1996. The number of pairs varied annually between nine and 19 and was positively correlated with spring counts of Rabbits in the current and previous years. This correlation probably results from a previously documented preference for very short vegetation strewn with small stones created by grazing and soil disturbance by Rabbits. The average number of young fledged per pair was adequate to maintain a stable population, but varied by an order of magnitude among years. Annual variation in chick survival had the largest influence on variation in overall productivity, because breeding failures at the egg stage were usually replaced. Differences in chick survival among years were not correlated with the mean rate of growth of chicks. Nest success and overall breeding success were positively correlated with a spring Rabbit count and, for nest s...

Methods for diagnosing causes of bird population declines are described, paying special attention to methods that rely on comparisons among geographical regions and/or time periods with different population trends. Comparisons of breeding productivity and survival among regions or periods provide a valuable check on the diagnosis of external causes of a decline indicated by correlation with population trend. Ringing or tagging programmes can give information on population levels and are the main source of information on survival. Age ratios from counts or catches of juveniles and adults in standardized trapping programmes can provide data on breeding productivity. Nest recording schemes yield estimates of productivity if females make one breeding attempt per year or if the number of attempts per female can be estimated from supplementary data. Population models should be used to explore hypotheses about the external causes and demographic mechanisms of population declines. Models are described which have ...

Survival and between-year movements of Corncrakes ringed as chicks and adult males were investigated in Scotland and Ireland. The probability of movement to sites at various distances from the ringing place was described by a modified random walk model. Most males returned to within a few kilometres of where they were ringed but there were indications that birds ringed as chicks dispersed further than adults. The dispersal model was combined with census data to estimate the probability of subsequent capture for each ringed individual and mean annual survival probabilities. First-year survival was estimated at 0.236, but with a wide confidence interval. Adult survival was estimated more precisely at 0.186. Independent data from studies of breeding success and population trends, taken with the estimated adult survival from recaptures, indicated a higher first-year survival rate (0.339), but the confidence intervals of the two estimates overlapped. Because adult survival was low, the rate of population growt...

During the last 30 years, there have been marked declines in the populations of many British songbirds breeding on farmland, while two of their main predators, sparrowhawk ( Accipiter nisus ) and magpie ( Pica pica ), have spread back into areas from which they had disappeared. The causes of the songbird declines remain unclear but given the coincidence in timing, it might appear that increased predation could be responsible. Although many studies have failed to find links between changes in the populations of breeding songbirds and mortality from avian predators, previous work has, with few exceptions, involved only short–term studies on small spatial scales. Here we use large–scale, long–term data from a national bird census scheme to examine whether magpies and sparrowhawks could have depressed the rates of year–to–year population change in 23 songbird species. Our results indicate that magpies and sparrowhawks are unlikely to have caused the songbird declines because patterns of year–to–year population change did not differ between sites with and without these predators.

The behaviour of Corncrakes during mechanized mowing of hay and silage was investigated by tracking radio-tagged females with broods and observing chicks escaping from meadows or being killed by the mower. Except in the case of very young chicks, Corncrakes were found to move away from mowers far and fast enough to avoid being overtaken, provided that an escape route to a refuge area was available. During mowing of meadows from the outside inwards (O-I), chicks stayed in the isolated plot of unmown grass until the last few swaths remained to be mown and 55% were killed. Mowing from the centre of the meadow outwards (I-O) has been reported to reduce chick mortality because chicks are able to escape to unmown cover outside the meadow without leaving the shelter of tall grass. However, the present study showed that chick mortality was also lower (32%) during I-O than O-I mowing when the grass bordering the plot being mown had already been cut. In these circumstances the proportion of chicks that escaped was ...

Recoveries of Stone‐curlews ringed in southern and eastern England show that they migrate through western France in autumn to winter in Spain, Portugal, Algeria, Morocco and West Africa. There was no difference in migration route or wintering area between birds from the breeding populations of south‐central and eastern England. Analysis of age at recovery indicated that 61% of juveniles survived from independence to 1 year old and that subsequent annual survival was 83%. Given these survival rates, 0.61 young would have to be reared to independence per pair per year to maintain the population. Recoveries within the breeding season indicate that natal dispersal leads to occasional movements between the two main populations of Stone‐curlews in England (Salisbury Plain and Breckland). The evidence for permanent emigration and/or immigration of breeding Stone‐curlews to and from populations in mainland Europe is equivocal. Even frequent transfers would be unlikely to be detected given current levels of ringin...

The corncrake has been declining in numbers and distribution in Britain for more than 100 years. Meadows mowed for hay or silage are the most frequent habitat and nests and broods placed there are often destroyed during mowing. Observations of radio-tagged females and watches of meadows during mowing are used to describe the timing of breeding, the duration of various stages of the breeding cycle and mortality rates of clutches and broods. It is shown that females frequently produce two clutches per season and that clutch and brood survival are high in the absence of mowing. The majority of nests are placed in meadows liable to be mowed during the breeding season and this proportion increases during the season. Mowing from the outside of the meadow towards the centre causes greater mortality of corncrake chicks than mowing from the centre outwards. A simulation model is developed to permit productivity (chicks reared to independence per female) to be estimated for a range of average mowing dates and for mowing from the outside inwards and from the centre outwards. The model indicates a large effect of the average date of mowing on productivity and only a small effect of the spread of mowing dates. Mowing from the centre of the field outwards is estimated to result in substantial increases in productivity via improved chick survival, especially when the average mowing date is early. Differences in productivity, estimated from average mowing dates, between regions of Britain and Ireland with stable or slowly declining corncrake populations and those with rapidly declining populations, are approximately large enough for differences in mowing practice to be the principal cause of the observed difference in population trend. Current conservation programmes for corncrakes in Britain and Ireland, which include payments to farmers to delay mowing and to mow from the centre of the field outwards, are evaluated using the simulation model. The improvement in productivity caused by the conservation measures should be sufficient to halt the long-term population decline provided that they can be implemented widely enough.

Reconciling the aims of feeding an ever more demanding human population and conserving biodiversity is a difficult challenge. Here, we explore potential solutions by assessing whether land sparing (farming for high yield, potentially enabling the protection of non-farmland habitat), land sharing (lower yielding farming with more biodiversity within farmland) or a mixed strategy would result in better bird conservation outcomes for a specified level of agricultural production. We surveyed forest and farmland study areas in southern Uganda, measuring the population density of 256 bird species and agricultural yield: food energy and gross income. Parametric non-linear functions relating density to yield were fitted. Species were identified as "winners" (total population size always at least as great with agriculture present as without it) or "losers" (total population sometimes or always reduced with agriculture present) for a range of targets for total agricultural production. For each target we determined whether each species would be predicted to have a higher total population with land sparing, land sharing or with any intermediate level of sparing at an intermediate yield. We found that most species were expected to have their highest total populations with land sparing, particularly loser species and species with small global range sizes. Hence, more species would benefit from high-yield farming if used as part of a strategy to reduce forest loss than from low-yield farming and land sharing, as has been found in Ghana and India in a previous study. We caution against advocacy for high-yield farming alone as a means to deliver land sparing if it is done without strong protection for natural habitats, other ecosystem services and social welfare. Instead, we suggest that conservationists explore how conservation and agricultural policies can be better integrated to deliver land sparing by, for example, combining land-use planning and agronomic support for small farmers.

SummaryThe Corncrake Crex crex is a rail which inhabits tall grass and herbage and migrates between breeding grounds in northern Eurasia and wintering areas in south-east Africa. Corncrake populations are known to have been declining for more than 100 years in some countries and declines have now been reported for almost all of the European part of the species's world range. It appears that mechanized mowing early in the breeding season reduces the production of young to a point below that needed to maintain the population. It might therefore be expected that Corncrakes would be least abundant in countries where the management of agricultural grassland is most mechanized and intensive. To test this hypothesis, an analysis of available statistics for agricultural intensity and Corncrake population density in different European countries was undertaken. Milk yield per dairy cow and measures of the use of fertilizers and tractors were used as indices of the intensity of management of agricultural grassland. Corncrakes were least abundant in European countries with high levels of milk yield, fertilizer and tractor use. Countries with low indices of agricultural intensity and high Corncrake abundance are in eastern Europe where continuing political change makes the future course of agricultural development difficult to foresee. The persistence of the Corncrake in this region depends on the adoption of agricultural policies which do not encourage further intensification of grassland management in those areas which support important populations.

SummaryFieldworkers counted traps, guns and nets used for bird trapping in sample sections of a 1 km wide strip of land adjacent to the shore on the Mediterranean coast of Egypt in the autumn of 1994. These data were used to estimate the number of traps, guns and nets in use in the whole 1 km coastal strip. Information obtained by interviewing bird trappers was used to estimate the number of Corncrakes taken per trap, net and gun in the 1993 and 1994 seasons and from this the total number taken was about 9,000 and 14,000 respectively. Trapping methods and intensity varied with locality but the taking of Corncrakes was widespread. It was estimated that about 9,000 people were involved in trapping and shooting in the coastal strip. The average proportion of the European Corncrake population taken per year on the coast was estimated to be in the range 0.5–2.7%, though this range would be lower if, as seems probable, Corncrakes from Asia are among those passing through Egypt. Further surveys are required to estimate the numbers of Corncrakes taken further inland.

Counts of singing male Corncrakes are often used to estimate population size, but they provide no information on the number of females. For much of the breeding season male Corncrakes sing almost continuously at night, but females are inconspicuous and have not been recorded to sing in the wild. During radio-tracking studies, male Corncrakes were found to be singing on 92% of night-time checks when they appeared not to have been accompanied by a female during the preceding day, but males accompanied by a female on the preceding day were only recorded singing on 12% of checks. Males were always silent when accompanied at night by a radio-tagged female. Wind speed and rainfall had no significant effect on the chance of a male being recorded singing. These findings suggest that surveillance of nocturnal song production could be used as a non-intrusive method of assessing whether male Corncrakes are attracting mates.

Radio‐tagged Corncrakes which incubated clutches and/or accompanied broods of chicks were not observed to sing. Birds which sang did not give parental care. Dissection of two birds which had been radio‐tracked indicated that the first group were females and the second group were males. This confirmed previous indications that, in the wild, only females care for the eggs and young and only males sing. The length of the head and bill and the maximum chord wing length were both greater in males than females. A linear discriminant function including these two measurements sexed 96% of birds correctly. Functions fitted separately to data from each of two study areas sexed 93% of birds correctly when applied to birds from the other area.

A survey of Golden Eagles was carried out in 1992 which, as far as possible, repeated that of 1982–83. In total, 422 pairs were located, 0.5% fewer than in 1982–83. However, changes between 1982–83 and 1992 in the number of pairs in 7 geographical regions varied between a 27% decline (from 22 pairs to 16) and a 28% increase (from 53 pairs to 68). The mean number of young reared per pair in 1992 was 0.32. There was no significant variation in breeding success among regions. Breeding success was lower in 1992 than in 1982 in 6 of the 7 regions. The proportion of 10-km National Grid squares which held pairs of Golden Eagles was positively correlated with the proportion of upland habitats within them, but there was also substantial geographical variation in population density, expressed as pairs per 100 km2 of upland. Some predominantly upland areas held no Golden Eagles whereas the areas with the highest densities, which were in western Scotland, held up to about 4 pairs per 100 km2 of upland.

A census of singing Corncrakes throughout Britain was carried out in 1993. Ten-kilometre National Grid squares in Scotland which held the species in 1978179 and/or 1988 were searched systematically by night. Elsewhere records of singing birds were obtained by means of publicity and checked for accuracy. A total of 480 singing males was counted in 83 10-km squares. Ninety-two per cent of the population was found in the Hebridean Islands. The total count was 17% smaller than in 1988 and at least 34% less than in 1978. The average rate of population decline between 1988 and 1993 was 3.5% per year, which was more rapid than during the previous 10 years. There were considerable differences among islands and areas in the rate of change of the Corncrake population. In some areas the population had increased, but in Orkney there had been an 82% decline in 5 years. Areas with high rates of decline between 1978 and 1988 also tended to show rapid declines between 1988 and 1993. The census results and conservation me...

In many colonial waterbirds, reproductive success is affected by water levels around the colonies. In a study of the Greater Flamingo (Phoenicopterus ruber roseus) in the Camargue, southern France, we examined annual variation in water levels around the breeding colony site between 1984 and 1991 in relation to (1) the number of breeding pairs, (2) colony productivity (fledglings per breeding pair), and (3) physical condition of fledg- lings. The number of breeding pairs each year was highly variable and was positively correlated with high water levels during the March-July period. There was no significant relationship between the number of breeding pairs and the number of chicks fledged. Although the productivity of the colony was not affected by water levels during the chick- raising period, fledglings were heavier in years with high water levels. There was no relationship between colony productivity or the absolute number of chicks fledged and the average body condition of chicks in the creche. Differences between the 1984 and 1985 cohorts in the frequency of young birds making breeding attempts (i.e., ages 5 and 6 yr) suggested that body condition at fledging may have important life history consequences. Estimation of reproductive performance in colonial waterbirds, usually limited to the av- erage nest productivity, could be improved by considering average body condition of chicks at fledging as well.

Populations of oriental white-backed vulture (Gyps bengalensis), long-billed vulture (Gyps indicus) and slender-billed vulture (Gyps tenuirostris) crashed during the mid-1990s throughout the Indian subcontinent. Surveys in India, initially conducted in 1991-1993 and repeated in 2000, 2002, 2003 and 2007, revealed that the population of Gyps bengalensis had fallen by 2007 to 0.1% of its numbers in the early 1990s, with the population of Gyps indicus and G. tenuirostris combined having fallen to 3.2% of its earlier level. A survey of G. bengalensis in western Nepal indicated that the size of the population in 2009 was 25% of that in 2002. In this paper, repeat surveys conducted in 2011 were analysed to estimate recent population trends. Populations of all three species of vulture remained at a low level, but the decline had slowed and may even have reversed for G. bengalensis, both in India and Nepal. However, estimates of the most recent population trends are imprecise, so it is possible that declines may be continuing, though at a significantly slower rate. The degree to which the decline of G. bengalensis in India has slowed is consistent with the expected effects on population trend of a measured change in the level of contamination of ungulate carcasses with the drug diclofenac, which is toxic to vultures, following a ban on its veterinary use in 2006. The most recent available information indicates that the elimination of diclofenac from the vultures' food supply is incomplete, so further efforts are required to fully implement the ban.

In a recent study (1), we analyzed the pattern of late Quaternary megafaunal extinctions in relation to changes in global climate and the timing of human arrival on different landmasses. Lima-Ribeiro et al. (2) write that some of the human arrival scenarios we considered are more plausible than others and that this affects the interpretation of our analysis. We incorporated a wide range of human arrival scenarios to allow precisely this sort of analysis, and we therefore welcome this contribution. To clarify, we considered 32 human arrival scenarios not to … [↵][1]2To whom correspondence may be addressed. E-mail: davidrwilliams87{at}gmail.com or grahamprescott{at}gmail.com. [1]: #xref-corresp-1-1

We estimate potential risks to human health in the UK from dietary exposure to lead from wild gamebirds killed by shooting. The main source of exposure to lead in Europe is now dietary. We used data on lead concentrations in UK gamebirds, from which gunshot had been removed following cooking to simulate human exposure to lead. We used UK food consumption and lead concentration data to evaluate the number of gamebird meals consumed weekly that would be expected, based upon published studies, to result in changes, over and above those resulting from exposure to lead in the base diet, in intelligence quotient (IQ), Systolic Blood Pressure and chronic kidney disease (CKD) considered in a recent opinion of the European Food Safety Authority (EFSA) to be significant at a population level and also in SAT test scores and in rates of spontaneous abortion. We found the consumption of

The late Quaternary period saw the rapid extinction of the majority of the world's terrestrial megafauna. The cause of these dramatic losses, especially the relative importance of climatic change and the impacts of newly arrived people, remains highly controversial, with geographically restricted analyses generating conflicting conclusions. By analyzing the distribution and timing of all megafaunal extinctions in relation to climatic variables and human arrival on five landmasses, we demonstrate that the observed pattern of extinctions is best explained by models that combine both human arrival and climatic variables. Our conclusions are robust to uncertainties in climate data and in the dates of megafaunal extinctions and human arrival on different landmasses, and strongly suggest that these extinctions were driven by both anthropogenic and climatic factors.

The stone curlew is a nocturnal bird which nests and forages on sparsely vegetated ground. Its population and geographical range in Britain have declined throughout the 20th century. Estimates of the size of a sub-population in the Breckland region of eastern England show that a decline which began in the 1940s or earlier continued up to the mid-1980s, but that the population was stable from 1985 onwards. A survey in 1987 indicated that stone curlews nested at the highest densities on fragments of formerly much more extensive short semi-natural dry grasslands and heaths (referred to throughout as heathland). However, most pairs bred at much lower density on spring-sown tilled farmland. An important part of the decline in the Breckland stone curlew population between 1968 and 1991 is attributable to a decline in the number of pairs nesting on heathland. Observations of stone curlews marked individually with colour rings showed that individuals did not nest exclusively on heathland or arable farmland. Some birds nested in both habitats in the same year and there were frequent moves between habitats from one year to the next. Year-to-year changes in the number of pairs of stone curlews nesting on heathland during a period of population stability were associated with variation in both the rate of return to heathland of ringed birds which previously nested on heathland and the proportion of surviving young adults with no previous breeding experience which nested on heathland. Some of the birds which were displaced from, or failed to recruit to, heathland nesting sites nested on arable land, but there was also evidence that a proportion of them did not attempt to breed. Measurements of sward height at heathland sites with a recent history of occupation by nesting stone curlews show that those sites which had been abandoned had taller swards than those where the birds remained. An index of the biomass of green vegetation was derived from satellite imagery obtained before and after a sharp decline in the number of heathland nesting stone curlews. It was found that the index had increased significantly more at heathland sites which had ceased to be used by stone curlews than at sites which continued to be used for nesting. The long-term decline in the number of stone curlews nesting on heathland is believed to have begun with the conversion of large areas of heathland for arable agriculture and forestry. However, it has continued during a period when little heathland was lost. Changes in vegetation structure and species composition associated with a reduction in grazing by rabbits and livestock are the most likely cause. Since 1985 breeding success has been enhanced by protection of eggs and chicks in arable crops from destruction by farming operations. Beginning in 1989 efforts have also been made to change the management of Breckland heaths. These include shallow ploughing and increased grazing by livestock, supported by payments from government under the Environmentally Sensitive Areas scheme. The number and proportion of stone curlews nesting on heathland has increased and the decline in the total population size has ceased. The relative contribution of different management factors to this change is not yet clear.

A study was carried out in native pinewoods at Abernethy and Glen Tanar to investigate the effect of forest fences on capercaillie and black grouse. Collisions occurred at a rate of 0.25 and 0.03 per km of fence per month for capercaillie and black grouse respectively. Male capercaillie had a higher proportion of severe and fatal collisions than females. Capercaillie tended to collide with those sections of fence where there were moderately sized pines (8.5 m) close (within 4.4 m) to the fence. Collision sites close to trees were most strongly associated with the height of exposed trunk, suggesting that capercaillie fly under the canopy and fail to see the fence. The annual mortality rate of radio-tagged capercaillie caused by collisions was 32 per cent indicating that this was a major mortality factor. Collisions were most frequent between September and November when capercaillie were dispersing. It is recommended that fences are removed where and when they are unnecessary, or are made more visible, or are set back from old woodland.

In light of the significance that ecosystem service research is likely to play in linking conservation activities and human welfare, systematic approaches to measuring, modeling and mapping ecosystem services (and their value to society) are sorely needed. In this paper we outline one such approach, which we developed in order to understand the links between the functioning of the ecosystems of Tanzania’s Eastern Arc Mountains and their impact on human welfare at local, regional and global scales. The essence of our approach is the creation of a series of maps created using field-based or remotely sourced data, data-driven models, and socio-economic scenarios coupled with rule-based assumptions. Here we describe the construction of this spatial information and how it can help to shed light on the complex relationships between ecological and social systems. There are obvious difficulties in operationalizing this approach, but by highlighting those which we have encountered in our own case-study work, we have also been able to suggest some routes to overcoming these impediments.

The question of how to meet rising food demand at the least cost to biodiversity requires the evaluation of two contrasting alternatives: land sharing, which integrates both objectives on the same land; and land sparing, in which high-yield farming is combined with protecting natural habitats from conversion to agriculture. To test these alternatives, we compared crop yields and densities of bird and tree species across gradients of agricultural intensity in southwest Ghana and northern India. More species were negatively affected by agriculture than benefited from it, particularly among species with small global ranges. For both taxa in both countries, land sparing is a more promising strategy for minimizing negative impacts of food production, at both current and anticipated future levels of production.