The Decline of the Bullfinch<i>Pyrrhula pyrrhula</i>in Britain: is the Mechanism Known?

Siriwardena, G.; Freeman, Stephen N.; Crick, Humphrey Q. P.

doi:10.3161/068.036.0207

Cited by 22 publications

(15 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The simplest approach is to estimate the population changes and the vital rates independently and then to draw them together in a population model (e.g. Freeman and Crick 2003;Peach et al 1999;Siriwardena et al 2001). Alternatively, one may estimate the vital rates and fit them to the census counts directly rather than to the index of numbers (Freeman et al 2007).…”

Section: Population Studiesmentioning

confidence: 99%

Citizens, science and bird conservation

2007

View full text Add to dashboard Cite

Collaborative research by networks of amateurs has had a major role in ornithology and conservation science and will continue to do so. It has been important in establishing the facts of migration, systematically recording distribution, providing insights into habitat requirements and recording variation in numbers, productivity and survival, thus allowing detailed demographic analyses. The availability of these data has allowed conservation work to be focussed on priority species, habitats and sites and enabled refined monitoring and research programmes aimed at providing the understanding necessary for sound conservation management and for evidencebased government policy. The success of such work depends on the independence of the science from those advocating particular policies in order to ensure that the science is unbiased. Wetland birds are surveyed in much of the world. Most countries also have a ringing scheme. Other forms of collaborative ornithology are strong in North America, Australia and Australasia, more patchily distributed in Asia (but with strong growth in some countries) and even patchier in Africa and South America. Such work is most successful where there is a strong partnership between the amateurs and the professional, based on their complementary roles. The participation of large numbers of volunteers not only enables work to be done that would otherwise be impossible but also facilitates democratic participation in the decisions made by society and builds social capital. The recruitment to and subsequent retention of people in the research networks are important skills. Surveys must be organized in ways that take into account the motives of the participants. It is useful to assess the skills of potential participants and, rather than rejecting those thought not to have adequate skills, to provide training. Special attention needs to be paid to ensuring that instructions are clear, that methods are standardized and that data are gathered in a form that is easily processed. Providing for the continuity of long-term projects is essential. There are advantages to having just one organization running most of the work in each country. Various sorts of organizations are possible: societies governed by their (amateur) members but employing professional staff to organize the work seem to be a particularly successful model. Independence from government and from conservation organizations is desirable.

show abstract

Section: Population Studiesmentioning

confidence: 99%

Citizens, science and bird conservation

2007

View full text Add to dashboard Cite

show abstract

“…Furthermore, recovery of Sparrowhawk numbers may have confined Bullfinches to feeding close to cover (through a behavioural response), and thus reduced the total land area over which they can forage, compared with the 1960s (Newton 1967). The demographic cause of decline is uncertain (Siriwardena et al 2001), but higher nest success was recorded during the decline , with no information on possible change in duration of breeding season or total seasonal productivity. The latter is greatly influenced by the amount of late summer nesting (Table 1; Newton 1999, Proffitt et al 2004.…”

Section: Referencesmentioning

confidence: 99%

The recent declines of farmland bird populations in Britain: an appraisal of causal factors and conservation actions

Newton

2004

Ibis

625

501

View full text Add to dashboard Cite

In this paper, the main aspects of agricultural intensification that have led to population declines in farmland birds over the past 50 years are reviewed, together with the current state of knowledge, and the effects of recent conservation actions. For each of 30 declining species, attention is focused on: (1) the external causes of population declines, (2) the demographic mechanisms and (3) experimental tests of proposed external causal factors, together with the outcome of (4) specific conservation measures and (5) agri-environment schemes. Although each species has responded individually to particular aspects of agricultural change, certain groups of species share common causal factors. For example, declines in the population levels of seed-eating birds have been driven primarily by herbicide use and the switch from spring-sown to autumn-sown cereals, both of which have massively reduced the food supplies of these birds. Their population declines have been associated with reduced survival rates and, in some species, also with reduced reproductive rates. In waders of damp grassland, population declines have been driven mainly by land drainage and the associated intensification of grassland management. This has led to reduced reproductive success, as a result of lowered food availability, together with increased disturbance and trampling by farm stock, and in some localities increased nest predation. The external causal factors of population decline are known (with varying degrees of certainty) for all 30 species considered, and the demographic causal factors are known (again with varying degrees of certainty) for 24 such species. In at least 19 species, proposed causal factors have been tested and confirmed by experiment or by local conservation action, and 12 species have been shown to benefit (in terms of locally increased breeding density) from options available in one or more agri-environment schemes. Four aspects of agricultural change have been the main drivers of bird population declines, each affecting a wide range of species, namely: (1) weed-control, mainly through herbicide use; (2) the change from spring-sown to autumn-sown cereal varieties, and the associated earlier ploughing of stubbles and earlier crop growth; (3) land drainage and associated intensification of grassland management; and (4) increased stocking densities, mainly of cattle in the lowlands and sheep in the uplands. These changes have reduced the amounts of habitat and /or food available to many species. Other changes, such as the removal of hedgerows and 'rough patches', have affected smaller numbers of species, as have changes in the timings of cultivations and harvests. Although at least eight species have shown recent increases in their national population levels, many others seem set to continue declining, or to remain at a much reduced level, unless some relevant aspect of agricultural practice is changed.Widespread population declines of farmland birds are of major conservation concern in Britain and other parts of Europe. S...

show abstract

“…The earlier approaches, including Peach, Siriwardena and Gregory (1999) and Siriwardena, Freeman and Crick (2001), fi tted population models to indices of abundance derived beforehand from census data. The demographic parameters in their deterministic population models were fi xed at their estimated values derived from nest record and ring-recovery data.…”

Section: Discussionmentioning

confidence: 99%

An Integrated Population Model From Constant Effort Bird-Ringing Data

Cave

King

Freeman

2010

JABES

Self Cite

View full text Add to dashboard Cite

Data from annual bird-ringing programmes, in which catch effort is standardised, are routinely used to index abundance, productivity and adult survival. Efficient models have been developed for each. Such monitoring schemes, based on ringing across a number of sites, are perhaps unique in providing this combination of demographic information and make the data particularly amenable to an integrated approach to population modelling. We develop a Bayesian approach and a deterministic population model uniting abundance, productivity and survival.The method is applied to Sedge Warbler Acrocephalus schoenobaenus data from the British Trust for Ornithology's Constant Effort Site scheme. The possibility of "transient" birds needs to be incorporated within this analysis. We demonstrate how current methodology can efficiently be extended to use additional data from multiple within-year recaptures when controlling for transience.

show abstract

The Decline of the BullfinchPyrrhula pyrrhulain Britain: is the Mechanism Known?

Cited by 22 publications

References 21 publications

Citizens, science and bird conservation

Citizens, science and bird conservation

The recent declines of farmland bird populations in Britain: an appraisal of causal factors and conservation actions

An Integrated Population Model From Constant Effort Bird-Ringing Data

Contact Info

Product

Resources

About