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Population Monitoring Program

Possessing annual estimates of black duck population characteristics, including abundance, sex and age structure, and vital rates (i.e., survival and recruitment) is critical to fulfilling the mission of the BDJV and achieving the goals of the NAWMP.  These estimates form the basis of black duck adaptive management and allow researchers and managers to assess model predictions, evaluate responses of black ducks to management, and track progress towards NAWMP goals.  Black duck population monitoring consists of three complementary programs: pre-season banding, the Mid-Winter Inventory, and Eastern Breeding Waterfowl Survey. 

Operational Programs Pilot Programs

Banding Program Mid-Winter Inventory Eastern Breeding Waterfowl Survey

Monitoring Seasonal Survival Rates (two-season banding program)

Introduction:

The goals of American black duck management are to ensure the future sustainability of the population and provide recreational opportunities, including sport harvest. To meet these goals managers and researchers require information about the abundance and distribution of populations, and vital rates (i.e., survival and mortality rates). Researchers and managers have principally relied on large-scale banding programs to obtain this information. Over the past 2-3 decades researchers and managers have been most interested in obtaining information on annual survival and harvest rates. Given these objectives researchers and managers have typically relied on banding programs consisting of a single banding period just prior to the hunting season (i.e., preseason; July-September) because it is the most efficient design (Brownie 1985, Nichols and Hines 1987). However, single-season banding operations have a variety of constraints. First, preseason banding is not the most logistically or financially efficient season to trap black ducks. Second, single-season banding programs do not provide information about seasonal survival rates thus limit our ability to model and contrast alternative hypotheses of population regulation (e.g., additive harvest mortality vs. post-season density dependence through changes in survival). This second limitation is particularly important because previous research and experience suggest management agencies cannot attain population goals through harvest management alone. Further, predictions of large-scale landscape and system changes (e.g., climate change) may influence the black duck population in ways not experienced or anticipated in harvest management programs. To address current management needs and address the impact of anticipated landscape and system changes on black ducks we need estimates of seasonal survival rates.

Goals and objectives:

The BDJV proposes to implement a 5-year pilot project to assess the potential of a 2-period (pre- and post-hunting season) banding program to estimate seasonal survival and harvest rates. A 2-period banding program will provide data to estimate survival during the summer/fall (August–January) and winter/spring (February–July). It will also provide data to estimate harvest rate analogous to estimates currently obtain from pre-season banding alone. The overall goal of this effort is to improve our ability to model black duck population dynamics and identify limiting factors that can be mitigated through habitat and harvest management. Our objectives are:
1. Use historic banding data to design protocols (i.e., season specific sample sizes and spatial allocation) that will provide point estimates of seasonal survival and harvest rates with annual coefficient of variation =10% and 5-year mean coefficient of =5%. 2. Implement 5-year pilot effort to test field and data analysis protocols. Resulting banding data will be used to evaluate success of field operations (i.e., meeting banding quotas), assumptions, data quality and applicability. 3. Use data from pilot effort to estimate required post-season banding sample needed to measure density dependent changes in post-season survival. 4. Revise protocols and make recommendations for operational implementation of 2-season banding program for American black ducks.

Monitoring Seasonal Survival Proposal

ABDU Winter Banding Protocol 2010/2011

Preliminary Report ABDU Winter Banding 2011

ABDU Winter Banding in Ontario Releasing a banded black duck ABDU Banding in NJ
Winter banding in Ontario. (photo credit: Anonymous). Canadian Wildlife Service Biologists releasing a banded black duck in Ontario, 2011. (photo credit: Canadian Wildlife Service). Black ducks captured during banding operations in New Jersey, 2011. (photo credit P. Devers).
Winter banding in Maine
Snow damage to a duck trap in Maine, Winter 2011. (photo credit: K. Sullivan).

Pilot Project: Banding moulting males in Ontario’s Hudson Bay Lowlands

The BDJV has provided support to the Ontario Ministry of Natural Resources to test field methodology to capture moulting male black ducks in northern Ontario.  The objective is to determine the feasibility of increasing the number of adult black ducks banded in Ontario annually by targeting moulting birds known to gather in the Hudson Bay Lowlands.  Biologists intend to increase the banded total in Ontario by 300-500 per year to help balance the continental distribution of banded black ducks and improve estimates of vital rates.

Assessing methodology to estimate black duck pre-hunting season age ratios

- Are Ratio Working Group

-Age Ratio Working Group Report 2011

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Banding: Banding is an important tool in migratory bird management. When combined with population and harvest data banding provides important information about population dynamics and structure, distribution, and derivation of harvest. This information in turn helps guide management activities. The first “Continental Waterfowl Banding Program” was issued jointly by CWS and USFWS in 1959. This cooperative plan, and subsequent updates in 1967, 1971, 1975, 1985, and 1989, has served as the principle framework for waterfowl banding and provides specific banding goals (i.e., quotas) by region for the black duck. Another update to the plan is currently in progress. Pre-season banding of black ducks is coordinated by two programs, the Eastern Canada Cooperative Banding Program (ECCBP) and the Northeast States Banding Program (NESBP). The ECCBP was initiated in 1963 to focus efforts on duck banding in eastern Canada and to obtain representative samples of black ducks and mallards. The ECCBP is coordinated by the banding committee of the Atlantic Flyway. Funding for the ECCBP is provided by the Atlantic Flyway, state and provincial agencies, and the BDJV. The NESBP is funded by the BDJV to increase the number of black ducks and mallards banded in northeastern U.S.

Table 1.  Number of black ducks banded in the pre-season (July–September) 2010 and 2009.


Location

2010

2009

% Change

New Brunswick

981

961

2

Newfoundland

465

427

9

Nova Scotia

101

192

-48

Ontario

249

305

-19

Prince Edward Island

67

4

1,675

Quebec

2862

2279

26

Connecticut

32

40

-20

Delaware

0

1

N/A

Maine

332

241

38

Maryland

11

0

N/A

Massachusetts

12

14

-15

New Hampshire

8

19

-58

New Jersey

25

31

-20

New York

45

20

225

North Carolina

2

0

N/A

Pennsylvania

31

34

-9

Rhode Island

4

0

N/A

Vermont

41

80

-49

Michigan

24

12

200

Minnesota

18

20

-10

Wisconsin

6

13

-54

Total

5316

4693

13

Note:  Pre-season Banding Data obtained from the Bird Banding Laboratory on 20 June 2011.
Pre-season banding data, combined with harvest survey data provides an estimate of annual black duck productivity.  Estimates of black duck productivity are based on the age ratio of harvested birds corrected for relative vulnerability (from banding data).  Black duck age ratios exhibited a drastic decline between 1997 and 2000, but productivity has been relatively constant since 2001.

Age ratios

<% ElseIf OpType = "MidWinter" then %> Mid-Winter Inventory: The Mid-Winter Inventory (MWI; also known as the Mid-Winter Survey) has been conducted in the United States since 1955. Because it provides the longest time series of black duck abundance data the MWI have been used extensively in research, particularly population modeling. However, the MWI has several limitations. First, it is only conducted in the United States so it does not provide an estimate of the entire wintering population. Second, recent research suggests the distribution of wintering black ducks may have shifted north, further limiting the usefulness of the MWI. Third, the MWI lacks the precision necessary to monitor population changes and does not provide estimates of variance. Finally, the MWI cannot be used to differentiate regional changes in breeding populations. A MWI has been conducted in Ontario by Environment Canada-Canadian Wildlife Service since 2002 and provides an index of abundance along the north shore of lake Ontario.

Mid-Winter Inventory

<% ElseIf OpType = "BPOP" then %> Eastern Breeding Waterfowl Survey (BPOP): Information and data on the black duck breeding population have been limited because the species breeds in eastern Canada, which is outside the traditional mid-continent breeding survey area (Fig. 1). Due to lack of information about the breeding population and limitations of the MWI, a breeding population survey program was initiated in 1990. The breeding population survey is conducted throughout black duck breeding range by the CWS and USFWS. However, the two agencies use different protocols. The CWS conducts plot surveys from helicopter, whereas the USFWS survey consists fix-winged transects. Estimates from the two surveys are integrated in a hierarchical model to produce a single estimate of the black duck breeding population. For the foreseeable future, the mid-winter and breeding population surveys will be conducted and used in research and management. However, it is anticipated that research and management will place greater reliance on the breeding population survey as the time series lengthens. The goals of the BDJV population monitoring program are to assess trends in the black duck population to evaluate progress towards NAWMP goals and develop, implement, and refine monitoring methodology. The USFWS produces black duck breeding population estimates at two different spatial scales-“core” and “total”. The core survey area has been surveyed since 1990 and the resulting data were used to calculate the NAWMP population goal and in the development of the Black Duck Adaptive Harvest Management framework. The total survey area has been monitored since 1998.

 

In 2010, the estimated breeding population (in the core area) was 565,000 (95% CI 479,000—624,300).  This estimate was 5% lower than the 2009 estimate (596,200 [95% CI 523,000—684,300) and 32% lower than the NAWMP Population Goal (830,000).   The 2010 estimate constitutes the 4th consecutive decline in the estimated black duck breeding population (in the core survey area).   The 2010 estimate for the entire survey area 804,000 (95% CI 667,000—1,040,000) which is 11% lower than the 2009 estimate (900,000 [95% CI 735,000—1,200,000).  However, at the scale of the total survey area the black duck population has not shown a consistent decline over the past 4 years. 

 

Black duck breeding grounds in central Quebec. (photo credit: P. Devers). Bell 206 Long Ranger Helicopter (Ontario Ministry of Natural Resources) used to survey breeding black ducks in the eastern boreal forest. (photo credit: P. Devers). Cessna 206 Amphibious aircraft (U.S.Fish and Wildlife Service) used to survey breeding black ducks in the eastern boreal forest. (photo credit: P. Devers).
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