|
Titre :
|
The timing and duration of primary moult of the Eurasian Oystercatcher Haematopus ostralegus in northern Scotland – effects of sex, age and year (2025)
|
|
Auteurs :
|
R.L. Swann, Auteur ;
Ron W. Summers, Auteur ;
Tanya Scott, Auteur ;
Les G. Underhill, Auteur
|
|
Type de document :
|
Article
|
|
Dans :
|
Ringing & Migration (40(1) June, 2025)
|
|
Article en page(s) :
|
74-80
|
|
Mots-clés:
|
East Atlantic Flyway
;
Moray Firth
;
Underhill–Zucchini models
;
climate change
|
|
Résumé :
|
The timing and duration of primary moult of Eurasian Oystercatchers Haematopus ostralegus that carry out post-nuptial moult and spend the winter in the Moray Firth, northern Scotland, varied according to their age and sex. There was also a long-term trend in timing. Based on samples collected over a 45-year period of 3800 actively moulting birds and 2032 with completed moult, the Underhill–Zucchini Data Type 4 model gave an estimation of moult duration of 133 days for adults, a value close to the estimate derived from the rate of growth (change of proportion of feather mass grown) of 0.007 per day from birds retrapped during moult (143 days). The mean date on which adults started moult was 21 July (95% range 8 June to 2 September) and they completed on 1 December (95% range 19 October to 13 January). With completion extending into winter, food resources in midwinter may not be limiting. Females started moult c. 10 days before the males. Subadults (older than second calendar year but not yet adult) started moult 34 days before the adults, and second-calendar-year birds 77 days before the adults. The second-calendar-year birds and subadults would have formed the bulk of the oversummering population. The start of moult became earlier at a mean rate of 0.17 days per year, equivalent to 7.8 days over the 45 years of the study.
|
|
En ligne :
|
https://doi.org/10.1080/03078698.2025.2587897
|
