22 research outputs found
RSPB-2016-0806 revised SOM from Demographic drivers of decline and recovery in an Afro-Palaearctic migratory bird population
Additional methodology for regional integrated population model
Supplementary Materials from Health hazards to wild birds and risk factors associated with anthropogenic food provisioning
Supplementary Methods, Figure and Table
Modelling the Progression of Bird Migration with Conditional Autoregressive Models Applied to Ringing Data
<div><p>Migration is a fundamental stage in the life history of several taxa, including birds, and is under strong selective pressure. At present, the only data that may allow for both an assessment of patterns of bird migration and for retrospective analyses of changes in migration timing are the databases of ring recoveries. We used ring recoveries of the Barn Swallow <i>Hirundo rustica</i> collected from 1908–2008 in Europe to model the calendar date at which a given proportion of birds is expected to have reached a given geographical area (‘progression of migration’) and to investigate the change in timing of migration over the same areas between three time periods (1908–1969, 1970–1990, 1991–2008). The analyses were conducted using binomial conditional autoregressive (CAR) mixed models. We first concentrated on data from the British Isles and then expanded the models to western Europe and north Africa. We produced maps of the progression of migration that disclosed local patterns of migration consistent with those obtained from the analyses of the movements of ringed individuals. Timing of migration estimated from our model is consistent with data on migration phenology of the Barn Swallow available in the literature, but in some cases it is later than that estimated by data collected at ringing stations, which, however, may not be representative of migration phenology over large geographical areas. The comparison of median migration date estimated over the same geographical area among time periods showed no significant advancement of spring migration over the whole of Europe, but a significant advancement of autumn migration in southern Europe. Our modelling approach can be generalized to any records of ringing date and locality of individuals including those which have not been recovered subsequently, as well as to geo-referenced databases of sightings of migratory individuals.</p></div
Progression of Barn Swallow migration in western Europe and north Africa.
<p>Contour plots of the date in which the CAR model predicts that a given percentage of Barn Swallows have been recorded during (A) spring and (B) autumn migration. Contours were generated by linear kriging interpolation. Numbers in the colour scale represent the mean date for each 10-days colour belt (1 January  =  1). For ease of interpretation we here report some reference dates: 100 = 31 March, 120 = 30 April; 150 = 30 May, 180 = 29 June, 200 = 19 July, 230 = 18 August, 260 = 17 September, 300 = 27 October.</p
Pulsed-field gel electrophoresis group and host origin of <i>Salmonella</i> Typhimurium isolates.
<p>Pulsed-field gel electrophoresis group and host origin of <i>Salmonella</i> Typhimurium isolates.</p
Distribution of <i>S.</i> Typhimurium DT40, DT56(v) and DT160 incidents, 1993–2012 in garden birds and humans.
<p>(a) Garden bird data expressed as total number of incidents by region (b) Human data expressed as number of incidents per 100,000 people by region, according to 2001 census data.</p
Number of garden bird incidents versus human incidents with <i>S</i>. Typhimurium infection by year, 1993–2012.
<p>Correlations for the individual phage types: DT56v r<sub>18</sub> = 0.80, P<0.001; DT160 r<sub>18</sub> = 0.59, P = 0.003 and DT40 r<sub>18</sub> = 0.39, P = 0.046.</p
Maps of Barn Swallow movements.
<p>Each line connects the ring and recovery position of individual Barn Swallows in (A) March-June and (B) August-October in the British Isles or in (C) February-June and (D) August-November in western Europe and north Africa. To facilitate the interpretation of the figure only Barn Swallows that moved more than 1 and less than 8 degrees latitude or longitude are shown.</p