The American Black Duck: Three Decades of Science-Based Adaptive Management

2018 ◽  
Vol 2 (1) ◽  
pp. 1-8
Author(s):  
Kevin M. Ringelman ◽  
Christopher K. Williams

The American black duck (Anas rubripes) population declined by 50% between 1955 and 1985, prompting more than three decades of intensive scientific research and strategic management. Analyses of band recovery data suggest that the historical declines may have been caused in part by harvest, but even with restrictive hunting regulations implemented in the mid 1980s, populations have not recovered. Increasing competition and hybridization with mallards (Anas platyrhynchos), coupled with habitat loss and fragmentation on northern breeding grounds are hypothesized to have contributed to a lower continental black duck population. Simultaneously, there is a concern that declines in the quantity and quality of wintering habitat—coastal salt marshes of the eastern United States—may have deleterious cross-seasonal effects on black duck demographics. Black ducks have a long legacy of intensive research and management, and ongoing threats to their populations make this a well-rooted and timely case study in science-based conservation.

2004 ◽  
Vol 82 (11) ◽  
pp. 1827-1831 ◽  
Author(s):  
Ronald E Kirby ◽  
Glen A Sargeant ◽  
Dave Shutler

Species ratios and rangewide distributions of American black ducks (Anas rubripes Brewster, 1902) and mallards (Anas platyrhynchos L., 1758) have undergone recent changes. Mechanisms behind these changes are not known with certainty, but recent investigations have focused on the possibility of competitive exclusion and the consequences of hybridization. Consequences of hybridization have been difficult to assess because of the difficulty in identifying hybrids beyond the F1 generation and lack of means to quantify introgression in wild populations. We documented a postmating isolating mechanism between the two species that follows Haldane's rule in controlled, interspecific matings in captive populations. Hybridization reduces the proportion of F1 females available to return to the breeding grounds in the subsequent year. This effect, although likely small in overall population consequences in any year, may be of local significance and may contribute to recent reports of range shifts in both American black ducks and mallards.


2000 ◽  
Author(s):  
Jerry R. Longcore ◽  
Daniel G. McAuley ◽  
Gary R. Hepp ◽  
Judith M. Rhymer

2000 ◽  
Author(s):  
Jerry R. Longcore ◽  
Daniel G. McAuley ◽  
Gary R. Hepp ◽  
Judith M. Rhymer

2015 ◽  
Vol 79 (2) ◽  
pp. 344-348 ◽  
Author(s):  
John M. Coluccy ◽  
Michael V. Castelli ◽  
Paul M. Castelli ◽  
John W. Simpson ◽  
Scott R. Mcwilliams ◽  
...  

1999 ◽  
Vol 77 (10) ◽  
pp. 1573-1578 ◽  
Author(s):  
Dave Shutler ◽  
C Davison Ankney ◽  
Adele Mullie

The blood parasite Leucocytozoon simondi is often associated with heavy mortality of ducks and geese, especially domestic ones, in North America. In contrast, in a previous study we found no mortality from L. simondi in our wild stock of mallard (Anas platyrhynchos) and American black duck (Anas rubripes) ducklings. However, because parasites can slow growth, which could extend the interval during which ducklings are susceptible to predators, we tested for parasite effects on growth rates. We analysed growth rates over the first 20 days of life, based on tarsus length, culmen, bill width, body mass, and a principal component of structural size. Growth rates of infected ducklings were not lower than those of uninfected ducklings. Similarly, more intense infections did not have a greater effect on growth rates. Hence, growth rates were not negatively affected by L. simondi, which suggests that effects of this parasite on wild duck populations have been overestimated.


1984 ◽  
Vol 62 (3) ◽  
pp. 452-456 ◽  
Author(s):  
Malcolm L. Hunter Jr. ◽  
Jack W. Witham ◽  
Hilary Dow

Aerially spraying ponds with carbaryl (Sevin-4-oilR) at 840 g active ingredient/ha reduced biomass and numbers of macroinvertebrates and decreased the growth rates of American black duck, Anas rubripes, and mallard. Anas platyrhynchos, ducklings in Maine. Ducklings on sprayed ponds spent more time searching for food and less time resting, and their rate of movement around the ponds was greater than for ducklings on unsprayed ponds.


2006 ◽  
Vol 70 (2) ◽  
pp. 450-459 ◽  
Author(s):  
CHARLES MAISONNEUVE ◽  
LUC BÉLANGER ◽  
DANIEL BORDAGE ◽  
BENOÎT JOBIN ◽  
MARCELLE GRENIER ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document