Nancy Ockendon

Declines in British-breeding populations of Afro-Palaearctic migrant birds are linked to bioclimatic wintering zone in Africa, possibly via constraints on arrival time advancement

Capsule The bioclimatic zone and habitat type within which birds winter are the most important determinants of population trends. Aims To investigate whether regional factors on wintering grounds, phenological mismatch, or habitat on breeding or wintering grounds show relationships with population changes of Afro-Palaearctic migrant birds. Methods We modelled breeding bird survey trends of 26 species of Afro-Palaearctic migrant birds that breed in Britain, and assessed the most important variables. We also investigated spatial variation in population trends within the UK. Results Bioclimatic zone and wintering habitat type were the most important determinants of population trend. After accounting for the effects of the other variables, species that spend the winter in southern Africa or the humid tropics of central and western Africa showed more negative population trends than those that winter in the arid zone. Species occupying open and woodland habitats declined and generalist species increased, on average. We also suggest that the effect of bioclimatic zone on population trends may be through constraints on the timing of migration. Conclusion Correlations between population change and both wintering area and winter habitat suggest regional changes in climate or land-use in the humid tropics are driving declines in many long-distance migrant species, possibly partly through migratory constraints.

Does the badge of status influence parental care and investment in house sparrows? An experimental test

Theory predicts that traits which signal parental quality might evolve in males of species with biparental care. In avian species, male ornaments may be the most likely candidates for such signals. Male house sparrows (Passer domesticus) possess a black throat patch often referred to as a “badge” or a “badge of status”. By assuming a trade-off between male attractiveness (reflected in male ornaments) and parental care under the differential allocation hypothesis, we predicted that badge size would be negatively correlated with male parental investment. An experiment in which the badge was enlarged in one group and unchanged in a control group was conducted. Our manipulation was predicted to affect female as well as male parental investment. However, we found that eight variables associated with parental investment—the start date for breeding, clutch size, male and female incubation time, male and female food provisioning rate, and average chick weight and the number of fledglings—barely differed between treatments. Also, little evidence for correlations between natural variation in badge size and any of these eight variables was found. Instead, the start date for breeding and the number of fledglings were significantly correlated with both male and female age, while clutch size increased with female age. Female condition was a positive predictor of clutch size and number of fledglings. Female tarsus length, unexpectedly, is related to both male and female incubation time. Badge size was also positively correlated with male age. However, parental age (male or female) was not related to parental care. We conclude that badge size does not signal parental quality, but that the ages of both sexes and the condition of the female play significant roles in the reproductive performance of this species.

A 2017 Horizon Scan of Emerging Issues for Global Conservation and Biological Diversity

We present the results of our eighth annual horizon scan of emerging issues likely to affect global biological diversity, the environment, and conservation efforts in the future. The potential effects of these novel issues might not yet be fully recognized or understood by the global conservation community, and the issues can be regarded as both opportunities and risks. A diverse international team with collective expertise in horizon scanning, science communication, and conservation research, practice, and policy reviewed 100 potential issues and identified 15 that qualified as emerging, with potential substantial global effects. These issues include new developments in energy storage and fuel production, sand extraction, potential solutions to combat coral bleaching and invasive marine species, and blockchain technology.

Climatic effects on breeding grounds are more important drivers of breeding phenology in migrant birds than carry- over effects from wintering grounds

Long-distance migrants may be particularly vulnerable to climate change on both wintering and breeding grounds. However, the relative importance of climatic variables at different stages of the annual cycle is poorly understood, even in well-studied Palaearctic migrant species. Using a national dataset spanning 46 years, we investigate the impact of wintering ground precipitation and breeding ground temperature on breeding phenology and clutch size of 19 UK migrants. Although both spring temperature and arid zone precipitation were significantly correlated with laying date, the former accounted for 3.5 times more inter-annual variation. Neither climate variable strongly affected clutch size. Thus, although carry-over effects had some impact, they were weaker drivers of reproductive traits than conditions on the breeding grounds.

Comparison of habitat‐specific trends in the abundance of breeding birds in the UK

Capsule Trends in the relative abundance of 18 out of 23 breeding bird species of conservation concern varied significantly between habitats. Aims To produce and compare habitat‐specific trends in abundance of widespread breeding birds of conservation concern in the UK. Methods Breeding Bird Survey data for 23 red‐ and amber‐listed species were compared across 12 habitat categories. Habitat preference indices were calculated for each species and population trends were compared between favoured and avoided habitats, with the expectation that declines would be greatest in avoided, assumed poorer‐quality, habitats (the buffer effect). Results Over 75% of species showed significant variation in trends in abundance across habitats. In some species the annual rate of change differed by more than 10% between habitats. There was no consistent relationship between the trend of a species within a habitat and its preference index for that habitat. Conclusions The rate at which species of conservation concern are changing in abundance varies between habitats. Some species are declining more quickly in preferred habitats, others in avoided habitats, showing little consistent support for the buffer effect. Habitat‐specific trends should be considered when deciding how best to focus conservation efforts.

Urbanization and time of arrival of common birds at garden feeding stations

Capsule Birds appeared at garden feeding stations later in the morning in urban areas than in rural areas during winter.

Eye size and the time of arrival of birds at garden feeding stations in winter

A nationwide volunteer survey was conducted to investigate the time at which common species of birds arrived at garden feeders in the morning during winter, and over 5,800 participants submitted observations. We examined the relationship between species’ eye size and their time of arrival at feeders, in order to investigate whether the time at which foraging was initiated was constrained by visual capability. There was a negative correlation between eye size and time of arrival at garden feeders across species, and this relationship remained significant when body mass was taken into account. This suggests that the time at which garden birds begin to forage on winter mornings may be limited by their visual capability at low light intensities.

What Works in Conservation 2015

What are the best means of reducing illegal hunting of primates? Does changing the type of livestock benefit heathland vegetation? Does removing the upper layer of peat enhance peatland restoration? Is flame treatment effective for dealing with invasive floating pennywort? What Works in Conservation has been created to provide practitioners with answers to these and many other questions about practical conservation. This book provides an assessment of the effectiveness of 1277 conservation interventions based on summarized scientific evidence. The 2018 edition contains new chapters covering practical global conservation of primates, peatlands, shrublands and heathlands, management of captive animals as well as an extended chapter on control of freshwater invasive species. Other chapters cover the global conservation of amphibians, bats, birds and forests, conservation of European farmland biodiversity and some aspects of enhancing natural pest control, enhancing soil fertility and control of freshwater invasive species. It contains key results from the summarized evidence for each conservation intervention and an assessment of the effectiveness of each by international expert panels. The accompanying website www.conservationevidence.com describes each of the studies individually, and provides full references.

Ten‐year assessment of the 100 priority questions for global biodiversity conservation

In 2008, a group of conservation scientists compiled a list of 100 priority questions for the conservation of the worlds biodiversity. However, now almost a decade later, no one has yet published a study gauging how much progress has been made in addressing these 100 high-priority questions in the peer-reviewed literature. We took a first step toward reexamining the 100 questions to identify key knowledge gaps that remain. Through a combination of a questionnaire and a literature review, we evaluated each question on the basis of 2 criteria: relevance and effort. We defined highly relevant questions as those that - if answered - would have the greatest impact on global biodiversity conservation and quantified effort based on the number of review publications addressing a particular question, which we used as a proxy for research effort. Using this approach, we identified a set of questions that, despite being perceived as highly relevant, have been the focus of relatively few review publications over the past 10 years. These questions covered a broad range of topics but predominantly tackled 3 major themes: conservation and management of freshwater ecosystems, role of societal structures in shaping interactions between people and the environment, and impacts of conservation interventions. We believe these questions represent important knowledge gaps that have received insufficient attention and may need to be prioritized in future research.