Douglas D.J.T.,University of Stirling |
Newson S.E.,Bto Inc. |
Leech D.I.,Bto Inc. |
Noble D.G.,Bto Inc. |
Robinson R.A.,Bto Inc.
Oikos | Year: 2010
In recent years, populations of long-distance migrant birds have declined markedly. Resource availability, both on breeding and wintering grounds, is likely to be important particularly since changing climates are affecting the timing and synchrony of such resources. We use novel analytical methods to examine whether large-scale population declines in the brood-parasite common cuckoo Cuculus canorus are the result of changes in the abundance or timing of breeding of its host species. We find that, due to climate-induced changes in the timing of breeding, availability of dunnock Prunella modularis nests has decreased, but that availability of reed warbler Acrocephalus scirpaceus has increased. Although there is no evidence that the timing of breeding of cuckoo has changed, these changes are likely to have had only a minimal impact on its population trend, but may explain an increase in the rate of parasitism of reed warbler nests in recent decades. © 2010 The Authors.
Morrison C.A.,University of East Anglia |
Robinson R.A.,Bto Inc. |
Clark J.A.,Bto Inc. |
Risely K.,Bto Inc. |
Gill J.A.,University of East Anglia
Diversity and Distributions | Year: 2013
Aim: Recent, rapid population declines in many Afro-Palaearctic migratory bird species have focussed attention on changing conditions within Africa. However, processes influencing population change can operate throughout the annual cycle and throughout migratory ranges. Here, we explore the evidence for impacts of breeding and non-breeding conditions on population trends of British breeding birds of varying migratory status and wintering ecology. Location: Great Britain (England & Scotland). Methods: Within- and between-species variation in population trends is quantified for 46 bird species with differing migration strategies. Results: Between 1994 and 2007, rates of population change in Scotland and England differed significantly for 19 resident and 15 long-distance migrant species, but were similar for 12 short-distance migrant species. Of the six long-distance migrant species that winter in the arid zone of Africa, five are increasing in abundance throughout Britain. In contrast, the seven species wintering in the humid zone of Africa are all declining in England, but five of these are increasing in Scotland. Consequently, populations of both arid and humid zone species are increasing significantly faster in Scotland than England, and only the English breeding populations of species wintering in the humid zone are declining. Main conclusions: Population declines in long-distance migrants, especially those wintering in the humid zone, but not residents or short-distance migrants suggest an influence of non-breeding season conditions on population trends. However, the consistently less favourable population trends in England than Scotland of long-distance migrant and resident species strongly suggest that variation in the quality of breeding grounds is influencing recent population changes. The declines in humid zone species in England, but not Scotland, may result from poorer breeding conditions in England exacerbating the impacts of non-breeding conditions or the costs associated with a longer migration, while better conditions in Scotland may be buffering these impacts. © 2013 John Wiley & Sons Ltd.
Douglas D.J.T.,University of Leeds |
Vickery J.A.,Bto Inc. |
Benton T.G.,University of Leeds
Agriculture, Ecosystems and Environment | Year: 2010
Managing arthropod populations on farmland for conservation purposes, such as food resources for declining farmland birds, requires information on the way distributions vary between crop types, for example under varying sowing regimes. In this study arthropods were sampled during one summer from fields of winter-sown and spring-sown barley. The relative timing of crop development had a strong influence on arthropod abundance between crop types, with winter barley supporting significantly higher abundance of total counts and many individual orders in early summer, but the reverse being the case in late summer. Fields of both crop types that received higher herbicide inputs showed reduced arthropod counts. © 2009 Elsevier B.V. All rights reserved.
Douglas D.J.T.,University of Leeds |
Benton T.G.,University of Leeds |
Vickery J.A.,Bto Inc.
Bird Study | Year: 2010
Capsule: No strong determinants of patch selection were found in set-aside; in cereal fields tractor tramlines were favoured. Aims: To examine and compare the factors influencing patch selection by Yellowhammers foraging for nestling food in set-aside and cereals. Methods: Observations of adults provisioning nestlings were made at 21 nests on lowland mixed farmland in northeast Scotland. Vegetation measurements and arthropod abundance from mapped foraging sites were compared with control sites within the same habitats. Results: In set-aside, no differences in vegetation and arthropods were found between foraging and control sites. In cereal fields, tractor tramlines with sparser vegetation than cropped areas were favoured. Conclusions: Set-aside typically offers a heterogeneous sward and birds foraging within this may be less restricted in their choice of accessible foraging sites, relative to the dense swards of intensively managed cereal crops. Recent policy changes have resulted in the reconversion of set-aside to more intensive cereal cropping; this may reduce the availability of beneficial foraging habitat for farmland birds. © 2010 British Trust for Ornithology.
Gillings S.,Bto Inc. |
Henderson I.G.,Bto Inc. |
Morris A.J.,RSPB |
Vickery J.A.,Bto Inc.
Ibis | Year: 2010
Between 1988 and 2007, set-aside, a European Commission production control measure, took an average of 10% of arable farmland in the EU out of production each year. In 2007, the set-aside rate was set to 0% and the scheme was later abandoned altogether. By assessing associations of farmland birds with set-aside and quantifying the extent of set-aside loss, this study aims to assess the implications of set-aside loss for farmland bird conservation. During the lifespan of set-aside, a large number of studies assessed the biodiversity value of set-aside and other agricultural crops and habitats. Where possible we considered measurable benefits of set-aside. However, some studies did not specify the type of set-aside and in some cases set-aside fields were grouped with cereal stubble fields. In these cases, we took the pragmatic approach of assessing the value of generic stubble fields as a conservative minimum estimate of the value of set-aside fields. A re-analysis of data from 30 intensive studies demonstrates that farmland bird densities tended to be higher on set-aside than on either cereal or oilseed rape crops. Without mitigation, these are the two crops likely to replace most set-aside fields. We estimate that 26-52% of the farmland populations of key granivorous passerines were present on stubble fields, giving an indication of the proportion of birds likely to be present on set-aside fields within this broader category. An extensive survey of lowland farmland during winters 1999/2000, 2000/2001 and 2002/2003, repeated in February 2008, showed a doubling of the number of 1-km squares with no stubble and a halving of the number of squares with more than 10 ha of stubble. After set-aside abandonment, 72% of squares had no stubble in the important late winter period, confirming that many of the former stubble fields were retained as set-aside. A simple correlative model suggests that this could cause a small increase in the rate of decline of Skylark Alauda arvensis and Yellowhammer Emberiza citrinella populations, assuming causal links between stubble area and demography. However, even if this assumption cannot be supported, these results clearly indicate that a significant proportion of some farmland bird populations will need to find alternative breeding and foraging habitats. © 2010 The Authors. Journal compilation © 2010 British Ornithologists' Union.
Pearce-Higgins J.W.,RSPB |
Pearce-Higgins J.W.,Bto Inc.
Ibis | Year: 2011
There is considerable interest in understanding how management may help species and populations cope with climate change (climate change adaptation). I used a population model describing the demography of a southern range-margin European Golden Plover Pluvialis apricaria population vulnerable to climate change to assess the potential benefits associated with site-based adaptation management. Two forms of management were simulated: (1) counteracting management to reduce the severity of the negative climate change impacts, simulated by increasing tipulid (cranefly) abundance, and (2) compensatory management to increase populations through an alternative mechanism, simulated by manipulating nest and chick predation rates. A 1°C rise was estimated to require a doubling of cranefly abundance, or a 35% increase in nest and chick survival rates, to maintain a stable population. For a 2°C rise, a four-fold increase in craneflies or an 80% increase in survival rates would be required for population stability. A model based on likely realistic estimates of the magnitude of benefit associated with both adaptation management options showed that combined, they may significantly reduce the severity of population decline and risk of extinction associated with a relatively large increase in temperature of 5.8°C above 1960-90 levels. Site-based adaptation management may therefore increase the resistance of Golden Plovers to some degree of future climate change. This model framework for informing climate change adaptation decisions should be developed for other species and habitats. © 2011 British Trust for Ornithology. Journal compilation © 2011 British Ornithologists' Union.
Holt C.,Bto Inc.
British Birds | Year: 2013
Records of the Great White Egret Ardea alba have increased significantly in Britain in the last 20 years.The species now occurs throughout the year in some parts of the country, and is sufficiently numerous for a population trend based on WeBS Core Counts to be produced.The source of the increase is probably the expanding populations in neighbouring countries, particularly the Netherlands - where there is now an established breeding population and 2,000+ wintering individuals - and France.The species' habitat requirements are reviewed in relation to research findings from the Netherlands and elsewhere, which may be relevant to the continued expansion of the British population. Following successful breeding by Great White Egrets on the Somerset Levels in 2012, further breeding attempts in Britain are likely, especially in response to appropriate wetland habitat creation and sympathetic management, and particularly through landscape-scale initiatives.
Bto Inc. | Date: 2013-05-29
Computer programs for using the internet and the worldwide web; Computer software that provides web-based access to applications and services through a web operating system or portal interface; Enterprise software in the nature of a database for non-transactional data and a search engine for database content. Business consultation services, namely, business process improvement and enterprise architecture design. Consulting in the field of virtualization technologies for enterprises and businesses.
Bto Inc. | Date: 2014-11-05
Computer programs for the enabling of access or entrance control; Computer programs for using the internet and the world wide web; Computer software for creating searchable databases of information and data; Computer software that provides web-based access to applications and services through a web operating system or portal interface.