For the first time, we estimated the population sizes of two swan species and four goose species from observations during the non-breeding period in East Asia. Based on combined counts from South Korea, Japan and China, we estimated the total abundance of these species as follows: 42,000–47,000 Whooper Swans Cygnus cygnus; 99,000–141,000 Tundra Swans C. columbianus bewickii; 56,000–98,000 Swan Geese Anser cygnoides; 157,000–194,000 Bean Geese A. fabalis; 231,000–283,000 Greater White-fronted Geese A. albifrons; and 14,000–19,000 Lesser White-fronted Geese A. erythropus. While the count data from Korea and Japan provide a good reflection of numbers present, there remain gaps in the coverage in China, which particularly affect the precision of the estimates for Bean, Greater and Lesser White-fronted Geese as well as Tundra Swans. Lack of subspecies distinction of Bean Geese in China until recently also limits our ability to determine the true status of A. f. middendorffii there, but all indications suggest this population numbers around 18,000 individuals and is in need of urgent attention. The small, highly concentrated and declining numbers of Lesser White-fronted Geese give concern for this species, as do the major declines in Greater White-fronted Geese in China (in contrast to numbers in Japan and Korea, considered to be a separate flyway). In the absence of any demographic data, it is impossible to interpret the causes of these changes in abundance. Improved monitoring, including demographic and tracking studies are required to provide the necessary information to retain populations in favourable conservation status.

Illegal killing/taking of birds is a growing concern across the Mediterranean. However, there are few quantitative data on the species and countries involved. We assessed numbers of individual birds of each species killed/taken illegally in each Mediterranean country per year, using a diverse range of data sources and incorporating expert knowledge. We estimated that 11–36 million individuals per year may be killed/taken illegally in the region, many of them on migration. In each of Cyprus, Egypt, Italy, Lebanon and Syria, more than two million birds may be killed/taken on average each year. For species such as Blackcap Sylvia atricapilla, Common Quail Coturnix coturnix, Eurasian Chaffinch Fringilla coelebs, House Sparrow Passer domesticus and Song Thrush Turdus philomelos, more than one million individuals of each species are estimated to be killed/taken illegally on average every year. Several species of global conservation concern are also reported to be killed/taken illegally in substantial numbers: Eurasian Curlew Numenius arquata, Ferruginous Duck Aythya nyroca and Rock Partridge Alectoris graeca. Birds in the Mediterranean are illegally killed/taken primarily for food, sport and for use as cage-birds or decoys. At the 20 worst locations with the highest reported numbers, 7.9 million individuals may be illegally killed/taken per year, representing 34% of the mean estimated annual regional total number of birds illegally killed/taken for all species combined. Our study highlighted the paucity of data on illegal killing/taking of birds. Monitoring schemes which use systematic sampling protocols are needed to generate increasingly robust data on trends in illegal killing/taking over time and help stakeholders prioritise conservation actions to address this international conservation problem. Large numbers of birds are also hunted legally in the region, but specific totals are generally unavailable. Such data, in combination with improved estimates for illegal killing/taking, are needed for robustly assessing the sustainability of exploitation of birds.

Demand for the ‘ivory’ casques of the Helmeted Hornbill Rhinoplax vigil appears to have risen very sharply, although the species is legally protected in every range state (Brunei, Indonesia, Malaysia, Myanmar, Thailand) and it is on Appendix I of CITES. Seizure records and other sources indicate that the majority of hornbills are being killed in Indonesia on the islands of Borneo and Sumatra and smuggled to China where the casques are carved for commercial sale. Between March 2012 and August 2014 a minimum 2,170 heads and/or casques were seized from the illegal trade in Indonesia and China in identifiable enforcement actions. Seizures were made from poachers, smugglers, processing facilities and retailers (both physical shops and online traders). Thirteen seizures occurred in Indonesia in which no fewer than 1,117 specimens were confiscated. In China, 18 seizures resulted in the confiscation of 1,053 specimens. Anecdotal evidence suggests the species is now rare in Indonesia but that demand, reflected in the high prices involved, will not soon abate. Efforts are therefore urgently needed to end this illegal trade, which is controlled by organised crime with interests in other wildlife products, to advertise the penalties for transgressors, and to create awareness of the law and the plight of the species among potential consumers.

Vulture populations are declining steeply worldwide. Vulture ‘restaurants’ or feeding stations are a tool for maintaining and monitoring numbers, but individual species may be disadvantaged by the effects of carcass distribution, carcass size and interspecific aggression. To test the degree to which restaurants give opportunities for each species to access the food provided, we studied behaviour and morphology in three Critically Endangered species of vulture in Cambodia: the gregariously breeding and feeding White-rumped Vulture Gyps bengalensis and Slender-billed Vulture G. tenuirostris, and the solitary Red-headed Vulture Sarcogyps calvus. We video-recorded attendance time, attendance order and dominance behaviour at different-sized carcasses. Interspecific aggression at carcasses was least frequently shown by the ‘small’ White-rumped Vulture. The relatively ‘large’ Slender-billed and ‘medium’ Red-headed Vultures showed aggression more regularly and at similar levels. However, the latter avoids conflict by waiting until Gyps vultures are no longer crowding at the carcass, although its arrival at carcasses was correlated with total number of vultures present. While more numerous than Red-headed, the two Gyps vultures are more dependent on large carcasses, which increases their vulnerability to further declines in wild large ungulate species. Body size, number of individuals, hunger levels and carcass size and availability all influence carcass attendance behaviour. An increase in the number and spatial distribution of restaurants as well as of carcass size range could boost numbers of all vulture species.

A prominent threat to European vultures has been sanitary regulations that banned the disposal of livestock carcasses. Changes in food abundance following these regulations have been associated with changes in vulture behaviour and demographic parameters, but to what extent diet changes are responsible for population declines is poorly understood. The Egyptian Vulture Neophron percnopterus is the smallest and most threatened European vulture species and has an opportunistic and diverse diet. In Eastern Europe, the Egyptian Vulture population is declining more rapidly than elsewhere but there is little information on diet composition and the relationship between diet and demographic parameters to inform conservation management. We examined whether Egyptian Vulture population declines in Bulgaria and Greece may have been associated with diet changes that affected breeding productivity by monitoring breeding success and collecting diet remains from 143 Egyptian Vulture breeding attempts between 2006 and 2013. We found no relationship between diet diversity or composition and productivity. However, there was a significant relationship between occupancy rate of territories and diet diversity, indicating that occupancy rate decreased with a very diverse or a very narrow diet and a higher proportion of wild animals or a lower proportion of livestock in the diet. There was no temporal change in diet diversity in Bulgaria after admission to the EU in 2007. We conclude that it is unlikely that diet limitations on reproductive output are a critical threat to Egyptian Vultures on the Balkan Peninsula. The relationship between diet diversity and territory occupancy rate may indicate that adult birds with a very narrow or a very broad diet may be more susceptible to consuming poisoned carcasses, and more information on the effect of diet availability on adult and juvenile survival would be useful to inform and improve conservation management actions.

The Critically Endangered Black-winged Myna Acridotheres melanopterus is being pushed towards the brink of extinction in Indonesia due to continued demand for it as a cage bird and the lack of enforcement of national laws set in place to protect it. The trade in this species is largely to supply domestic demand, although an unknown level of international demand also persists. We conducted five surveys of three of Indonesia’s largest open bird markets (Pramuka, Barito and Jatinegara), all of which are located in the capital Jakarta, between July 2010 and July 2014. No Black-winged Mynas were observed in Jatinegara, singles or pairs were observed during every survey in Barito, whereas up to 14 birds at a time were present at Pramuka. The average number of birds observed per survey is about a quarter of what it was in the 1990s when, on average, some 30 Black-winged Mynas were present at Pramuka and Barito markets. Current asking prices in Jakarta are high, with unbartered quotes averaging USD 220 per bird. Our surveys of the markets in Jakarta illustrate an ongoing and open trade. Dealers blatantly ignore national legislation and are fearless of enforcement actions. Commercial captive breeding is unlikely to remove pressure from remaining wild populations of Black-winged Mynas. Efforts to end the illegal trade in this species and to allow wild populations to recover are urgently needed. We also recommend the immediate inclusion of Black-winged Mynas in Appendix III of CITES to allow for international support to Indonesia in clamping down on international trade of the species.

The European Commission’s 1979 Wild Birds Directive bans member states from hunting wild birds during spring, the period during which they are breeding or migrating, as hunting wild birds before they have reproduced is perceived to have a greater effect on bird populations than it would in autumn or winter. Malta is the only European Union member state to allow recreational wild bird hunting in spring, when birds migrate over the country to their European breeding grounds. Malta’s derogation of the European Commission’s ban can only be legally permissible if no alternative solutions to spring hunting exist. Using figures provided by hunters, we show that greater numbers of European Turtle-dove Streptopelia turtur and Common Quail Coturnix coturnix – the two species for which spring hunting is allowed – are hunted in autumn than in spring. We show that statistics on the number of birds hunted in spring, which hunters are legally obliged to provide to authorities, are under-reported: they are not correlated, at times negatively correlated, with data on the daily influxes of birds, and they spike in the final week of the season, consistent with the hypothesis that hunters under-report to avoid reaching quotas which would result in an early season closure. Finally, while there are wide error margins around the numbers, independent annual estimates of turtle-doves hunted in Malta imply spring hunting is a conservation concern beyond the country itself. Each spring, hunters in Malta kill the equivalent of between 2.4% and 4.4% of Europe’s turtle-dove population and 0.4% and 0.5% of its quail population.

With the combination of worldwide landscape changes and the uncertainty about the impact on species abundance and distribution, the value of spatio-temporal modelling tools is increasingly obvious. The Little Bustard Tetrax tetrax breeds on low-intensity arable cultivation and pastoral land and is currently threatened by diverse landscape modifications. The aim of this research was to predict Little Bustard population trends in the face of realistic scenarios of land use and infrastructure changes, applying a recently developed spatially explicit framework, based on the stochastic dynamic methodology (StDM). The application of this approach provided some basis to analyse the responses of breeding populations’ spatial distribution and abundance to the scenarios implemented. Since some of these scenarios represent local and/or regional risks to the viability of Little Bustard breeding populations, the results obtained demonstrate the potential of the proposed framework for landscape planning in the scope of the conservation of this threatened species. This approach also provides a promising baseline to support ecological risk assessments for other species, derived from ecological models with increased predictive power and intuitiveness to decision makers and environmental managers.

During 1998–2011, in an area of western Cyprus spanning about one-quarter of the global breeding range of the endemic Cyprus Warbler Sylvia melanothorax, the species declined at a rate of c.59% decade-1, suggesting that there is an urgent need to review its global conservation status. This decline has coincided with the recent, rapid colonisation of western Cyprus by the Sardinian Warbler S. melanocephala, whose numbers have increased substantially within the study area, as might be expected of a newly colonising breeding species. To identify possible causes of the Cyprus Warbler’s decline we compared its rate of change with measures of land-cover, vegetation density, altitude, rainfall and the presence of Sardinian Warblers at survey sites. The rate of decline in the Cyprus Warbler’s abundance was strongly correlated with land-cover and with the duration of site occupancy by Sardinian Warbler; Cyprus Warbler abundance had declined more steeply on sites colonised by Sardinian Warblers early in the survey period than on sites colonised later. Furthermore, on sites surveyed by BirdLife Cyprus in 2006–2014, Cyprus Warbler abundance had continued to decline significantly (also by c.59% decade-1) in western Cyprus, while Sardinian Warbler abundance had continued to increase. In contrast, Cyprus Warbler abundance showed no significant change in central and eastern Cyprus, where Sardinian Warblers were sparse or absent during the breeding season. These findings are consistent with at least two contrasting scenarios: that changes have occurred in land-cover or climatic conditions in Cyprus, to the detriment of Cyprus Warbler and to the benefit of Sardinian Warbler; or that in western Cyprus at least, the two species may compete for similar resources, despite a lack of evidence of this in an earlier, more detailed study. In either case, we suggest the need for a thorough, nationwide breeding survey of the two species.

Alien species can cause severe impacts in their introduced ranges and management is challenging due to the large number of such species and the diverse nature and context of their impacts. Lists of the most harmful species, like the “100 of the World’s Worst” list collated by the Invasive Species Specialist Group of the International Union for Conservation of Nature (IUCN) or the “100 of the Worst” invaders in Europe collated by the Delivering Alien Invasive Species Inventories in Europe (DAISIE) project, raise awareness about these impacts among the public, and can guide management decisions. Such lists are mainly based on expert opinion, but in recent years a more objective comparison of impacts has become possible, even between highly diverse taxa. In this study, we use a semi-quantitative generic impact scoring system to assess impacts of the three birds listed among the “100 of the World’s Worst” IUCN list (IUCN100) and the four birds on the list of “100 of the Worst” European invaders by DAISIE (DAISIE100) and to compare their impacts with those of other alien birds not present on the respective lists. We found that generally, both lists include some of the species with the highest impacts in the respective regions (global or Europe), and these species therefore deserve the dubious honour of being listed among the “worst”. However, there are broad overlaps between some species with regards to the impact mechanisms and the related issues of invasions, especially those of the Common Myna Acridotheres tristis and Red-vented Bulbul Pycnonotus cafer on the IUCN100, are very similar which might not warrant listing both species. To make the selection of species on such lists more transparent we suggest moving beyond lists based on expert opinion to a more transparent and defendable system for listing alien species based on published records of their impacts and related mechanisms.

The Upper Mustang region of Nepal holds important breeding populations of Himalayan Griffon Gyps himalayensis. Despite this species being considered ‘Least Concern’ on the IUCN Red List, the population in Upper Mustang had declined substantially in the early to mid-2000s. During that period, the non-steroidal anti-inflammatory drug diclofenac was commonly used to treat illness and injury in domesticated ungulates throughout Nepal. The timing and magnitude of declines in Himalayan Griffon in Upper Mustang resemble the declines in resident populations of the ‘Critically Endangered’ White-rumped Vulture Gyps bengalensis and Slender-billed Vulture Gyps tenuirostris in Nepal, both of which are also known to be highly sensitive to diclofenac. Since 2006, the veterinary use of diclofenac has been banned in Nepal to prevent further vulture declines. In this paper, we analyse the population trend in Himalayan Griffon in Upper Mustang between 2002 and 2014 and show a partial recovery. We conclude that the decline is now occurring at a slower rate than previously observed and immigration from areas where diclofenac was either not or rarely used the probable explanation for the recovery observed.

During autumn migration, people set trammel nets along most of the Mediterranean coast of Egypt, with migrating Common Quail Coturnix coturnix as their primary target. These nets capture large numbers of quail, but also illegally capture other birds, which are then killed. We present the results of surveys from 2008 to 2012 along these lines of nets on the coast of North Sinai, Egypt. In desert scrub, which covers most of the Sinai coast, the mean number of quail killed reached a high of 357.1 per km per day in 2012, with a grand mean over the study period of 191.9 per km per day. Trammel nets also captured 54 other bird species in 28 families. Species captured at the highest rates in desert scrub included Corncrake Crex crex, Isabelline Wheatear Oenanthe isabellina and Greater Short-toed Lark Calandrella brachydactyla. Based on mean rates of capture from 2008 to 2012 in desert scrub and sand bar habitats, we estimate 2.0 million quail and 0.5 million birds of other species are killed annually in North Sinai during the 45 days of peak migration. In 2012, however, after the use of MP3 players to attract quail became widespread, we estimate that 3.3 million quail and 0.5 million other birds were captured. Hunters near the coast have recently begun covering shrubs and trees with mist nets to catch passerines. From 2010 to 2012, mist nets along our survey routes caught birds of 17 species in three families, with seven of these species caught only in this type of net. Hunting is likely to be a contributing factor to population declines for some species that migrate across Egypt and further studies of migratory bird hunting along the southern Mediterranean shore are badly needed.

Parrot poaching and the subsequent illegal trade in the Neotropics are exacerbating the decline in parrot populations. Little is known, however, on where, when and how parrots are poached. The goals of this study were to identify the spatio-temporal patterns of parrot poaching in order to identify ways in which poaching could be reduced, using parrot data (9,013 individuals from 27 species) collected daily in a major illicit wildlife market in Santa Cruz de la Sierra, Bolivia, in 2005. Parrot data identified the individuals by species, age, date of arrival at market, and the poaching location. Parrot poaching strongly varied seasonally, with differences among municipalities, species, and age classes. While almost 90% of parrots were poached within a 234 km radius of the market, 84% originated from seven municipalities in which two of them accounted for 56% alone. With regard to species, six of the 27 market species accounted for nearly 90% of total individuals. A disproportionate share of parrots (47%) arrived between July and September. Poaching of adults and juveniles peaked however at different times of the year, offering valuable information for species where very little is known about their breeding phenology. Contrary to the idea that most parrot trade comes from nest poaching, most poached parrots (c.70%) were adults, which outnumbered juveniles in 21 out of the 26 native species. Therefore, the detrimental effects of parrot poaching are higher than simple trade numbers would suggest when considering that harvesting of adults has a stronger impact on the population viability and risk of extinction of long-lived species. Based on the findings, we recommend the allocation of police and conservation resources to patrol particular areas at particular times of the year in order to reduce the likelihood of poaching by species, age classes, and conservation status.

Management of threatened and endangered populations of wildlife increasingly relies upon active intervention such as predator control, habitat manipulation, and ex situ breeding or care. One tool that has received consideration for the management of declining or threatened avian populations is headstarting, or the artificial incubation of eggs and subsequent placement of newly hatched chicks in original or foster nests. We assessed the feasibility of implementing a headstarting program for the American Oystercatcher Haematopus palliatus, a species of high conservation concern in the eastern USA. Annual productivity is often low and lost during incubation, suggesting artificial incubation could enhance annual productivity. We used a control-impact approach to assign nests as either control or headstart and measured daily survival rate, success of parents accepting headstarted chicks, attendance patterns and behaviours of parents, and chick survival. We also implemented a transparent scoring process to rate the success of each step and the overall program. Daily survival rates of nests were significantly higher at headstart compared to control nests, and parents continued to incubate when eggs were well secured at nest sites. Attendance patterns and behaviour did not differ between headstart and control parents, and parents readily accepted healthy chicks whether they were returned to original or foster nests. Chick survival and subsequently annual productivity were, however, not higher at headstart compared to control nests suggesting that although we were able to enhance nest survival, low chick survival was still limiting annual productivity. Ultimately, headstarting may be most appropriate for American Oystercatchers where productivity is lost primarily to flooding, predation, or disturbance during the incubation stage but not during the chick-rearing stage. If, for example, high rates of nest loss are due to predators that also may prey upon chicks, then headstarting may not be an effective conservation tool.

The South African Fynbos biome, a global biodiversity hotspot with high endemism and species richness, has six endemic bird species. These are important not only intrinsically, but also for ecological functioning and as flagships for South Africa’s economically valuable avitourism sector. Little is known about population sizes or realised distribution ranges of these six species, but projected range modelling based on occurrence from the South African Bird Atlas Project (SABAP) has suggested these species are vulnerable to climate change. We estimate global population sizes for these six endemics based on densities calculated from two intensive biome-wide point count surveys in 2012. We modelled regions of suitable climatic space, from which we established that mean annual temperature and the temperature of the warmest quarter of the year appear to limit Cape Rock-jumper Chaetops frenatus and Protea Canary Serinus leucopterus ranges. Both species have seen an apparent > 30% decrease in range and reporting rates (a proxy for abundance) in the twenty years between SABAP atlas periods (1987–1991 and 2007–ongoing). The Cape Rock-jumper result is unexpected: encounter rates are higher in shorter vegetation, dry slopes and habitats with more recent occurrence of fire – all proxies for proximate causes of climate change on the Fynbos. Although coastal plains are highly transformed, mountain Fynbos is the best protected of all the world’s Mediterranean-climate habitats, with relatively little anthropogenic land transformation. Long term weather datasets from the Fynbos demonstrate significant warming since 1960. We conclude from these lines of evidence that these decreases are consistent with the loss of suitable climate space and inability of these species to adjust physiologically to increasing temperatures.

Currently, renovation and thermal insulation of buildings is happening at a high rate in many European countries, driven in part by the political aim to reduce greenhouse gas emissions. Unfortunately, building renovations often lead to a loss of structures, such as accessible cavities, on which synanthropic species, for example house-nesting birds, depend. In Germany, due to legislative regulations, it is a common practice to install nest-boxes as compensation for destroyed nest sites of birds. However, studies on the efficacy of such measures remain sparse. We monitored the occupancy of 477 compensatory nest-boxes for Common Swifts Apus apus, predominantly placed on renovated prefabricated buildings in a city in Germany. We found 24.3% of the boxes occupied by Swifts. On most buildings, the number of occupied boxes was as high as or even higher than the assumed number of breeding sites prior to renovation. Furthermore, in a district where nearly all buildings had been renovated in the past 10 years, we recorded a remarkably high density of Swifts breeding in nest-boxes. Using boosted regression trees, we analysed whether eight different nest-box properties influenced box occupation probability. The number of neighbouring boxes was the most important. Additionally, box age, facade orientation, city district, relative and absolute height, and manner of installation (external/internal) also played a role. Between different nest-box types, we found only negligible differences in occupation probability. Our findings suggest that installing nest-boxes is likely to be an appropriate measure to compensate for nesting sites of Swifts lost during building renovations. Based on our results, we recommend mounting the boxes a few metres apart from each other and close to the roof edge to maximise success. Further studies should be carried out to assess whether our results and conclusions can be confirmed in other situations.

Ritenbenk/Innaq in Disko Bay is the only remaining Thick-billed Murre colony in central West Greenland. It has declined by 72% since 1980 and now (2012) holds c.1,100 breeding pairs. In 2005–2006 and 2011–2012, a number of studies were carried out in this colony to improve our understanding of the population decline and its causes. Hunting has previously been identified as a problem for the colony, but local breeding conditions have never been studied and the non-breeding distribution was known only from ringing. Our studies showed that breeding success was moderate to good in the Ritenbenk colony and apparently not limited by food availability. The impact of gull predation was more uncertain, but seemed limited in our study plot. In contrast, estimates of maximum sustainable harvest levels showed that hunting, including illegal activities, was and still is too high and probably can explain much of the population decline. It is puzzling though, that the steepest population decline was observed within the most recent decade when the harvest level was markedly reduced. This may indicate that something else besides hunting mortality affects the colony. The winter distribution of the Ritenbenk birds includes areas in the central North Atlantic, such as the waters around South Greenland, where conditions have been identified as potentially deteriorating due to pronounced oceanographic changes. The potential impact on the Ritenbenk colony, as well as other colonies in the North Atlantic, needs to be studied further.

The Northern Silvery Grebe Podiceps juninensis is an aquatic bird species considered Vulnerable to extinction in Ecuador and Endangered in Colombia. Globally the species is considered Near Threatened. Herein we report recent changes in distribution and population trends for the subpopulation in the northern Andes (Ecuador, Colombia), which is small and isolated. The Northern Silvery Grebe has undergone two documented extirpations, and at least one colonisation event, over the last three decades. More than 90% of the subpopulation relies on two wetlands, La Mica and Colta lakes in Ecuador, with the latter facing an accelerated sedimentation process which jeopardizes the fate of the wetland, and the species, in the mid-term. The population of La Mica lost 80% of its birds in 2000 after the damming of the lake, but then remained stable over our census period (2004–2013). In contrast, the Colta population results from a recent colonisation in the early 2000s, and has experienced an exponential growth since then (annual population multiplication rate: 1.464). The growth of this population is so fast that it must include an important contribution of immigrants. The temporal coincidence between the drop in population size at lake La Mica and the colonisation of lake Colta suggests that the Colta population was founded by immigrants from La Mica. Finally, the absence of current reports of the species at wetlands in Colombia suggests that the species remains at very low numbers, bolstering the shrinkage in northern distribution.

Sustainable ecotourism requires careful management of human impacts on wildlife. Contrasting responses to the disturbance caused by ecotourism are observed across taxa and within species, because species and populations can differ in their tolerance to humans. However, the mechanisms by which tolerance develops remain unclear. Penguin colonies are popular tourist attractions. Although ecotourism increases public awareness and generates conservation income, it can also disturb penguins, raising concerns for threatened species such as the African Penguin Spheniscus demersus, whose populations are in rapid decline. We compared the tolerance of African Penguins to human disturbance across four colonies with contrasting histories of human exposure. Human approaches invoked the least response at colonies where human exposure was highest, suggesting increased human tolerance with increased exposure. The response to humans close to the nest also decreased more rapidly in highly exposed individuals within colonies. These results were consistent independent of breeding stage, and were repeated among colonies. Because the impacts of human disturbance, including temporary nest desertion, were greatest at the colony with least human exposure, human disturbance of breeding African Penguins potentially may be mitigated through increased levels of tolerance to humans, or displacement of shyer individuals, although this could not be assessed in the present study.

However, human exposure could significantly increase stress, impair reproduction and even reduce genetic diversity. Consequently, ecotourism must be managed carefully to minimize population level impacts, potentially by facilitating habituation in populations subject to non-threatening human disturbance, and maintaining some areas free of disturbance to allow shy individuals to breed.

Ludwig’s Bustard Neotis ludwigii is globally ‘Endangered’ because of a projected population decline resulting from high collision mortality on power lines throughout its southern African range. Population monitoring is key to the effective conservation of threatened species, but there are no population trend data to confirm the impact of this mortality. We repeated extensive road and aerial census counts of Ludwig’s Bustards and other large terrestrial birds, previously conducted in the late 1980s, across the Karoo, South Africa. An aerial survey gave similar density patterns to a concurrent road count, suggesting that road counts are an adequate method for censusing Ludwig’s Bustards. In common with the 1980s surveys, there was a strong seasonal effect in the Succulent Karoo, with Ludwig’s Bustards abundant in winter and rare in summer. There was no evidence of a corresponding decline in the Nama Karoo in winter, but this probably relates to reduced detectability in the Nama Karoo in summer as there is evidence for large proportions of the population migrating between biomes. No relationship was found between the numbers of Ludwig’s Bustards and rainfall, perhaps because of larger scale rainfall patterns in the Karoo and/or because the species is not strictly nomadic. Compared with the 1980s, Ludwig’s Bustards were more strongly associated with transformed lands, which have increased marginally on road count transects. Using Distance, the current South African population is estimated at 114,000 (95% CI 87,000-148,000) birds, with no evidence for a population decline over the past two decades. Numbers of Blue Cranes Anthropoides paradiseus increased since the 1980s, corresponding with other data supporting this trend, but numbers of Karoo Korhaan Eupodotis vigorsii, Southern Black Korhaan Afrotis afra and Blue Korhaan E. caerulescens all decreased, raising concerns about the conservation status of these resident bustard species.