NDLI: Changes in age and sex ratios amongst samples of hunter-shot wings from common duck species in Denmark 1982

Content Provider	Springer Nature Link
Author	Christensen, Thomas K. Fox, Anthony D.
Copyright Year	2013
Abstract	There are almost no long-term demographic monitoring programmes of commoner waterbird species, yet such data are fundamental to our understanding of drivers of population change. In the present study, we present annual age and sex ratios in samples of shot duck wings forwarded on a voluntary basis by hunters throughout Denmark from 1982 to 2010 for eight common quarry species. Wigeon, Shoveler, Pintail and Goldeneye showed statistically significant declines in the proportions of young birds in the samples, but only Wigeon showed a statistically significant decline in the proportion of females in the adult sample over this period. Amongst Wigeon, the proportions of first winter birds and females were lower amongst the sample shot over decoys compared with those shot without decoys, suggesting these two shooting methods differentially select for young birds and females. However, the slopes of declines in these proportions shot with and without decoys over time did not differ. We found no correlations between North Atlantic Oscillation index values and the proportions of young for any of the species or between May and June temperatures on the breeding areas of Wigeon and the proportions of young in samples derived the following winter. With the exception of Wigeon, little is known about how well the shot duck wing samples reflect the true ratios in the populations, and unravelling the error and bias associated with these samples remains a high future research priority. If long-term declines in age and sex ratio in the wing surveys reflect true trends in the Wigeon population as a whole, we have strong grounds for concern for this population, and effort should be invested in increased demographic surveillance to better understand the causes of these changes. We need improved methods to derive unbiased measures of annual breeding of our common duck species if we are to be better able to understand the population dynamics of these stocks and be effective in their management. In the meantime, the Danish wing survey represents a unique time series of reproductive success for many common migratory duck species and must be maintained and further exploited.
Starting Page	303
Ending Page	312
Page Count	10
File Format	PDF
ISSN	16124642
Journal	European Journal of Wildlife Research
Volume Number	60
Issue Number	2
e-ISSN	14390574
Language	English
Publisher	Springer Berlin Heidelberg
Publisher Date	2013-12-14
Publisher Place	Berlin, Heidelberg
Access Restriction	One Nation One Subscription (ONOS)
Subject Keyword	Hunting Population dynamics Breeding success Demographic monitoring Seasonal mortality Age and sex hunting bias Zoology Animal Ecology
Content Type	Text
Resource Type	Article
Subject	Ecology, Evolution, Behavior and Systematics Management, Monitoring, Policy and Law Nature and Landscape Conservation

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Seasonal variation in the sex and age composition of the woodcock bag in Denmark

Sex/age ratio bias in hunter wings of Eurasian Wigeon Anas penelope compared to field samples

Seasonal mortality in denmark: the role of sex and age (2003).

Seasonal variation in Eurasian Wigeon Anas penelope sex and age ratios from hunter-based surveys

Descriptive Findings Seasonal mortality in Denmark: the role of sex and age (2003)

Patterns of hunting mortality in Norwegian moose (Alces alces) populations

Quota hunting of Eurasian lynx in Norway: patterns of hunter selection, hunter efficiency and monitoring accuracy

Temporal quota corrections based on timing of harvest in a small game species

Hunter feedback of individually marked wild boar Sus scrofa L.: dispersal and efficiency of hunting in northeastern Germany

Changes in age and sex ratios amongst samples of hunter-shot wings from common duck species in Denmark 1982–2010

Similar Documents

Seasonal variation in the sex and age composition of the woodcock bag in Denmark

Sex/age ratio bias in hunter wings of Eurasian Wigeon Anas penelope compared to field samples

Seasonal mortality in denmark: the role of sex and age (2003).

Seasonal variation in Eurasian Wigeon Anas penelope sex and age ratios from hunter-based surveys

Descriptive Findings Seasonal mortality in Denmark: the role of sex and age (2003)

Patterns of hunting mortality in Norwegian moose (Alces alces) populations

Quota hunting of Eurasian lynx in Norway: patterns of hunter selection, hunter efficiency and monitoring accuracy

Temporal quota corrections based on timing of harvest in a small game species

Hunter feedback of individually marked wild boar Sus scrofa L.: dispersal and efficiency of hunting in northeastern Germany

Changes in age and sex ratios amongst samples of hunter-shot wings from common duck species in Denmark 1982–2010