Action before certainty for Africa's European migrant birds

Developing and implementing initiatives to stem population declines requires knowing whether they are driven by changes in breeding success or survival. For most migrant passerines we are struggling to provide this information—but why

The impact of land use change on migrant birds in the Sahel

Drought and environmental degradation in the drylands of West Africa are widely cited as a possible cause of population decline in migrant birds that winter or stage in the Sahel. Low rainfall was an important factor in declines of long-distance migrants in the 1960s and 1970s, but longer-term declines are likely to be complex in causation, affected by factors operating on any or all of breeding grounds, migration routes or wintering grounds. Human activities have had profound effects on land use in the Sahel in the last four decades, as farmers, livestock keepers and other resource users have responded to drought and economic and social change. Localised ecological studies of habitat use by migrant birds in the Sahel have been undertaken, but a systematic understanding of the place of land use change in the decline of Afro-Palaearctic migrants is still lacking. This paper uses a systematic review of published scientific literature to assess the evidence base for the links between dryland environmental change in the Sahel and numbers of migrant birds that winter in this region. It analyses the extent to which understanding is based on fieldwork in the Sahel itself and concludes that, despite the scientific consensus about the significance of human land use change on bird numbers, field evidence is greatly lacking. The two land use changes for which most evidence exist are loss of wetland and woodland habitats for which impacts on migrant bird species are largely, but not uniformly, negative. More direct research on the links between bird populations and dryland land use change in the Sahel is urgently needed.This paper grew from the project ‘Reversing the declines of African-Palaearctic migrants: understanding the social and economic factors driving land use change in sub-Saharan West African wintering areas’, funded by the CCI Fund (Cambridge Conservation Initiative) and the Isaac Newton Trust. Project partners were the British Trust for Ornithology, the Royal Society for the Protection of Birds, and the Departments of Geography and Zoology, University of Cambridge.This is the accepted manuscript. The final version is available from Taylor and Francis at http://www.tandfonline.com/doi/abs/10.1080/14888386.2014.931822?journalCode=tbid20#.VRAjki6Qne4

Garden varieties: how attractive are recommended garden plants to butterflies?

One way the public can engage in insect conservation is through wildlife gardening, including the growing of insect-friendly flowers as sources of nectar. However, plant varieties differ in the types of insects they attract. To determine which garden plants attracted which butterflies, we counted butterflies nectaring on 11 varieties of summer-flowering garden plants in a rural garden in East Sussex, UK. These plants were all from a list of 100 varieties considered attractive to British butterflies, and included the five varieties specifically listed by the UK charity Butterfly Conservation as best for summer nectar. A total of 2659 flower visits from 14 butterfly and one moth species were observed. We performed a principal components analysis which showed contrasting patterns between the species attracted to Origanum vulgare and Buddleia davidii. The “butterfly bush” Buddleia attracted many nymphalines, such as the peacock, Inachis io, but very few satyrines such as the gatekeeper, Pyronia tithonus, which mostly visited Origanum. Eupatorium cannibinum had the highest Simpson’s Diversity score of 0.75, while Buddleia and Origanum were lower, scoring 0.66 and 0.50 respectively. No one plant was good at attracting all observed butterfly species, as each attracted only a subset of the butterfly community. We conclude that to create a butterfly-friendly garden, a variety of plant species are required as nectar sources for butterflies. Furthermore, garden plant recommendations can probably benefit from being more precise as to the species of butterfly they attract

Defining the key wintering habitats in the Sahel for declining African-Eurasian migrants using expert assessment

SummaryThe Sahel in West Africa is a major wintering area for many western Palearctic migrants. The breeding populations of many of these have declined over the past 50 years. However, there have been few intensive field studies on migrant ecology in the Sahel and these were generally within a very restricted area. Consequently our knowledge of the distribution of species within this extensive area and the habitat associations of these species is limited. Understanding these habitat associations is essential for the effective conservation management of populations. We brought together a group of experts and consulted a wider group by email to assess the main Sahelian habitat types used by 68 African-Eurasian migrant bird species. Those species that showed strongest declines during 1970–1990 were associated with more open habitats than those newly declining during 1990–2000, when declining species were associated with habitats with more shrubs and trees. Populations of species that winter in the Sahel are generally stable or increasing now as rainfall has increased and is now near the long-term average for the Sahel. Those which use the Sahel only as a staging area are, in many cases, in rapid decline at present.We would like to thank Andy Clements, Paul Donald, Lincoln Fishpool and Mike Mortimore for contributing to the workshop and Peter Jones, Ian Newton, Volker Salewski, Tim Wacher, Eddy Wymenga and Leo Zwarts for useful comments by email on draft habitat importance scores. This study was funded by the Newton Trust and the Cambridge Conservation Initiative Collaborative Fund, supported by Arcadia. WJS is funded by Arcadia.This is the accepted manuscript of a paper published in Bird Conservation International, Volume 24, Issue 04, December 2014, pp 477-491, DOI: http://dx.doi.org/10.1017/S0959270913000531, Published online: 24 February 201

Can sacrificial feeding areas protect aquatic plants from herbivore grazing? Using behavioural ecology to inform wildlife management

Effective wildlife management is needed for conservation, economic and human well-being objectives. However, traditional population control methods are frequently ineffective, unpopular with stakeholders, may affect non-target species, and can be both expensive and impractical to implement. New methods which address these issues and offer effective wildlife management are required. We used an individual-based model to predict the efficacy of a sacrificial feeding area in preventing grazing damage by mute swans (Cygnus olor) to adjacent river vegetation of high conservation and economic value. The accuracy of model predictions was assessed by a comparison with observed field data, whilst prediction robustness was evaluated using a sensitivity analysis. We used repeated simulations to evaluate how the efficacy of the sacrificial feeding area was regulated by (i) food quantity, (ii) food quality, and (iii) the functional response of the forager. Our model gave accurate predictions of aquatic plant biomass, carrying capacity, swan mortality, swan foraging effort, and river use. Our model predicted that increased sacrificial feeding area food quantity and quality would prevent the depletion of aquatic plant biomass by swans. When the functional response for vegetation in the sacrificial feeding area was increased, the food quantity and quality in the sacrificial feeding area required to protect adjacent aquatic plants were reduced. Our study demonstrates how the insights of behavioural ecology can be used to inform wildlife management. The principles that underpin our model predictions are likely to be valid across a range of different resource-consumer interactions, emphasising the generality of our approach to the evaluation of strategies for resolving wildlife management problems

grazing and biodiversity conservation highlights on a natura 2000 network site

This paper provides a summarisation of information on the biodiversity of Natura 2000 sites of Basilicata and the impacts of grazing on protected habitats and species. Besides, using a case study of a site particularly rich in biodiversity as an example, we described the application of the Driving Force, Pressure, State, Impact and Response (DPSIR) framework to evaluate the impacts of grazing and to propose corrective measures for ensuring restoration and conservation of habitats

Mister Mary Somerville: Husband and Secretary

Mary Somerville’s life as a mathematician and savant in nineteenth-century Great Britain was heavily influenced by her gender; as a woman, her access to the ideas and resources developed and circulated in universities and scientific societies was highly restricted. However, her engagement with learned institutions was by no means nonexistent, and although she was 90 before being elected a full member of any society (Società Geografica Italiana, 1870), Somerville (Figure 1) nevertheless benefited from the resources and social networks cultivated by such institutions from as early as 1812. A key intermediary between Somerville and these societies was her husband, Dr. William Somerville, whose mediation was vital to her access to knowledge and her subsequent career as a scientific author. In this paper we will consider how spousal cooperation enabled the overcoming of gendered barriers to scientific institutions in the nineteenth century

Insights into the migration of the European Roller from ring recoveries

AbstractDespite recent advances in avian tracking technology, archival devices still present several limitations. Traditional ring recoveries provide a complementary method for studying migratory movements, particularly for cohorts of birds with a low return rate to the breeding site. Here we provide the first international analysis of ring recovery data in the European Roller Coracias garrulus, a long-distance migrant of conservation concern. Our data comprise 58 records of Rollers ringed during the breeding season and recovered during the non-breeding season. Most records come from Eastern Europe, half are of juveniles and over three quarters are of dead birds. Thus, ring recoveries provide migration data for cohorts of Rollers—juveniles and unsuccessful migrants—for which no information currently exists, complementing recent tracking studies. Qualitatively, our results are consistent with direct tracking studies, illustrating a broad-front migration across the Mediterranean Basin in autumn and the use of the Arabian Peninsula by Rollers from eastern populations in spring. Autumn movements were, on average, in a more southerly direction for juveniles than adults, which were more easterly. Juvenile autumn recovery direction also appeared to be more variable than in adults, though this difference was not statistically significant. This is consistent with juveniles following a naïve vector-based orientation program, and perhaps explains the ‘moderate’ migratory connectivity previously described for the Roller. In the first (qualitative) analysis of Roller non-breeding season mortality, we highlight the high prevalence of shooting. The recovery age ratio was juvenile-biased in autumn but adult-biased in spring. Although not statistically significant, this difference points towards a higher non-breeding season mortality of juveniles than adults. Our study demonstrates the complementarity of ring recoveries to direct tracking, providing an insight into the migration of juvenile Rollers and non-breeding season mortality

Threat-sensitive anti-predator defence in precocial wader, the northern lapwing Vanellus vanellus

Birds exhibit various forms of anti-predator behaviours to avoid reproductive failure, with mobbing—observation, approach and usually harassment of a predator—being one of the most commonly observed. Here, we investigate patterns of temporal variation in the mobbing response exhibited by a precocial species, the northern lapwing (Vanellus vanellus). We test whether brood age and self-reliance, or the perceived risk posed by various predators, affect mobbing response of lapwings. We quantified aggressive interactions between lapwings and their natural avian predators and used generalized additive models to test how timing and predator species identity are related to the mobbing response of lapwings. Lapwings diversified mobbing response within the breeding season and depending on predator species. Raven Corvus corax, hooded crow Corvus cornix and harriers evoked the strongest response, while common buzzard Buteo buteo, white stork Ciconia ciconia, black-headed gull Chroicocephalus ridibundus and rook Corvus frugilegus were less frequently attacked. Lapwings increased their mobbing response against raven, common buzzard, white stork and rook throughout the breeding season, while defence against hooded crow, harriers and black-headed gull did not exhibit clear temporal patterns. Mobbing behaviour of lapwings apparently constitutes a flexible anti-predator strategy. The anti-predator response depends on predator species, which may suggest that lapwings distinguish between predator types and match mobbing response to the perceived hazard at different stages of the breeding cycle. We conclude that a single species may exhibit various patterns of temporal variation in anti-predator defence, which may correspond with various hypotheses derived from parental investment theory