Wissenschaftliche Papiere

Schlagwörter: Grauspecht; Picus canus; Habitatmodellierung; Verbreitungsgrenze; Radiotelemetrie.

Zusammenfassung und weitere Informationen zur Dissertation online unter: 

https://ediss.uni-goettingen.de/handle/11858/00-1735-0000-002E-E419-D

Jacques Laesser & Rien E. van Wijk (2018)

Ringing & Migration, Volume 32, 2017 - Issue 2

ABSTRACT

In most bird species, all feathers are moulted at least once per year, usually after breeding (complete post-breeding moult). Woodpeckers (Picidae) often retain some primary coverts and secondaries during their otherwise complete post-breeding moult. To date, this phenomenon has received little attention and has not been studied thoroughly in European woodpeckers, even though it could prove very helpful for ageing and therefore for demographic studies. We studied the moult patterns of breeding adult Wrynecks Jynx torquilla in a Swiss Alpine valley between 2013 and 2016. Due to intensive ringing in the study area prior to the current study, our data set included birds of known age. Some individuals were captured and their moult documented in up to four years in a row. We found that Wrynecks present an extreme case of delayed primary-covert moult. No primary covert (PC) was renewed during the post-juvenile moult. At most three PCs were renewed by the second post-breeding moult and three to six at more advanced ages. That some juvenile PCs were retained until the sixth calendar year has not previously been documented for a species with such a relatively short lifespan. This principle of ‘postponed moult’ in Wrynecks affects the appearance of the PCs differently in each age class and allows us to age birds more accurately than previous methods. Here we describe how to interpret the moult pattern of PCs to age Wrynecks properly and argue that the moult strategy of Wrynecks was hitherto incompletely and in many cases mistakenly understood, leading to confusion in the ageing of Wrynecks.

Link to this article: https://doi.org/10.1080/03078698.2017.1437889 

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Paper zur Beobachtung eines trommelnden Mittelspechtes von Tobias Münchenberg, erschienen im Aves, Band 6 (Jahrgang 7), S.52, 2016. Die Online Version gibt es hier 

Elisabeth C. Charman a , Ken W. Smith b , Ian A. Dillon a , Steve Dodd a , Derek J. Gruar a , Andrew Cristinacce a , Phil V. Grice c & Richard D. Gregory a a Royal Society for the Protection of Birds, The Lodge, Sandy, Bedfordshire, SG19 2DL, UK b 24 Mandeville Rise, Welwyn Garden City, Hertfordshire, AL8 7JU, UK

c Natural England, 3rd floor Touthill Close, City Road, Peterborough, PE1 1XN, UK Version of record first published: 24 Feb 2012.

Abstract

Capsule The breeding success of Lesser Spotted Woodpeckers Dendrocopos minor is now lower in England than previously reported and also lower than found in studies elsewhere in Europe. Aims To quantify the breeding success and identify the causes of nest failure. To test the hypotheses that breeding success is related to aspects of food limitation and parental care, and inclement weather during the nesting period, or to interactions with Great Spotted Woodpeckers. Methods Nests were monitored in three regions of England, recording survival and causes of failure. We measured aspects of food limitation and parental care, rainfall and Great Spotted Woodpecker interactions at nests, to explore whether there was any evidence that these factors were related to breeding success. We compared results to other studies from the UK and continental Europe. Results Nest survival was 52%. The average number of chicks produced from successful nests was 2.8. Chick-stage daily nest survival was positively related to provisioning rates, indicating that food supply may be limiting. The most common cause of nest failure was presumed starvation of chicks after the disappearance of an adult. Some females ceased visiting nests, leaving provisioning solely to the male. This behaviour has been reported elsewhere in Europe, but in the present study males were unable to compensate fully by increasing their provisioning rates, leading to poor nest survival. Provisioning rates and chick-stage daily nest survival were negatively associated with rainfall. Nest predation by Great Spotted Woodpeckers occurred but was a less frequent cause of failure. Aggressive interactions were recorded between the two woodpecker species but these were unrelated to breeding parameters. Conclusions Low breeding success is most probably related to food shortages in the breeding period. Simple population modelling using parameters from the present study and from published work shows that if the low productivity that we have observed is replicated throughout Britain, it would be sufficient to account for the observed population decline. However, the possibility that survival rates are also low cannot be ruled out.

Link to the article: http://bit.ly/1RiC3gw