Seasonal and Diel Changes in the Feeding Behaviour of Some Dabbling Duck Species on a Breeding Lake in Northern Sweden

1982 ◽  
Vol 13 (2) ◽  
pp. 129 ◽  
Author(s):  
Kjell Danell ◽  
Kjell Sjoberg
2006 ◽  
Vol 70 (3) ◽  
pp. 799-804 ◽  
Author(s):  
JOSHUA T. ACKERMAN ◽  
JOHN M. EADIE ◽  
MICHAEL L. SZYMANSKI ◽  
JASON H. CASWELL ◽  
MARK P. VRTISKA ◽  
...  
Keyword(s):  

2014 ◽  
Vol 20 (1) ◽  
pp. 41 ◽  
Author(s):  
P-J Guay ◽  
A Taysom ◽  
R Robinson ◽  
J P Tracey

Waterbirds are currently facing various threats throughout the world. One threat that is often overlooked is hybridization with introduced species. This threatening process is especially significant for dabbling ducks (Genus Anas). The Mallard (Anas platyrhynchos) has been introduced to various parts of the world and now hybridizes and threatens numerous Anas species. In this paper, we review hybridization between Mallards and dabbling ducks with a specific emphasis on threats to the Pacific Black Duck (A. superciliosa). We then present an overview of the potential mechanisms of hybridization and discuss monitoring techniques. We conclude by proposing management strategies and speculating on the future of native dabbling duck species.


Ibis ◽  
2012 ◽  
Vol 155 (1) ◽  
pp. 80-88 ◽  
Author(s):  
Lars Dalby ◽  
Anthony D. Fox ◽  
Ib K. Petersen ◽  
Simon Delany ◽  
Jens-Christian Svenning
Keyword(s):  

2017 ◽  
Vol 9 (5) ◽  
pp. 10141
Author(s):  
Ardea Mingoa Licuanan ◽  
Mariano RoyMartin Duya ◽  
Perry Sim Ong ◽  
Ian Kendrich Carandang Fontanilla

DNA barcoding is extensively used as a species identification and delineation tool.  The aim of this study was to generate a barcode profile for mitochondrial cytochrome c oxidase subunit 1 (COI) in the Philippine Duck Anas luzonica, a dabbling duck species endemic to the Philippines that is classified as ‘Vulnerable’ by the International Union for Conservation of Nature (BirdLife International 2016).  COI barcodes were successfully obtained using muscle tissue samples from 46 A. luzonica individuals confiscated from illegal hunters in Pantabangan, Nueva Ecija.  Analysis of TrN+Γ+I distances among the Anas luzonica COI sequences and those of 25 other Anas species revealed that COI barcodes cannot generally delineate hybridizing species.  While Anas luzonica was differentiated from other species it is known to hybridize with and formed a monophyletic group in the neighbor-joining tree generated, sampling from areas of sympatry is needed since individuals were obtained from only one sampling site.  The population structure of the Anas luzonica population was also examined using mitochondrial DNA control region and COI sequences.  The population had high haplotype diversity and low nucleotide diversity, an indication that a bottleneck event had occurred, which is likely due to extreme hunting pressures and habitat destruction.  The population under study exhibited high genetic diversity.  Given that the samples for this study came from a single locality, sampling from other localities is required to determine whether other populations are facing the risk of reduced fitness (inbreeding depression).


2012 ◽  
Vol 49 (3) ◽  
pp. 163-170 ◽  
Author(s):  
Seon-Deok Jin ◽  
Md. Rashedul Hoque ◽  
Dong-Won Seo ◽  
In-Kyu Kim ◽  
Cheorun Jo ◽  
...  

2019 ◽  
Vol 46 (6) ◽  
pp. 533
Author(s):  
Fiona McDuie ◽  
Michael L. Casazza ◽  
David Keiter ◽  
Cory T. Overton ◽  
Mark P. Herzog ◽  
...  

Abstract Context Effective wildlife management requires information on habitat and resource needs, which can be estimated with movement information and modelling energetics. One necessary component of avian models is flight speeds at multiple temporal scales. Technology has limited the ability to accurately assess flight speeds, leading to estimates of questionable accuracy, many of which have not been updated in almost a century. Aims We aimed to update flight speeds of ducks, and differentiate between migratory and non-migratory flight speeds, a detail that was unclear in previous estimates. We also analysed the difference in speeds of migratory and non-migratory flights, and quantified how data collected at different temporal intervals affected estimates of flight speed. Methods We tracked six California dabbling duck species with high spatio-temporal resolution GPS–GSM transmitters, calculated speeds of different flight types, and modelled how estimates varied by flight and data interval (30min to 6h). Key results Median migratory speeds were faster (but non-significant) for the larger mallard (Anas platyrhynchos; 82.5kmh–1), northern pintail (Anas acuta; 79.0kmh–1) and gadwall (Mareca strepera; 70.6kmh–1), than the smaller-bodied northern shoveler (Spatula clypeata; 65.7kmh–1), cinnamon teal (Spatula cyanoptera; 63.5kmh–1) and American wigeon (Mareca Americana; 52kmh–1). Migratory flights were faster than non-migratory flights for all species and speeds were consistently slower with an increasing data interval. Implications The need to balance time and energy requirements may drive different speeds for migratory and non-migratory flights. Lower speeds at longer intervals are likely to be due to a greater proportion of ‘loafing’ time included in flighted segments, demonstrating that data acquired at different intervals provide a means to evaluate and estimate behaviours that influence speed estimation. Shorter-interval data should be the most accurate, but longer-interval data may be easier to collect over lengthier timeframes, so it may be expedient to trade-off a degree of accuracy in broad-scale studies for the larger dataset. Our updated flight speeds for dabbling duck species can be used to parameterise and validate energetics models, guide management decisions regarding optimal habitat distribution, and, ultimately, improve conservation management of wetlands for waterfowl.


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