Conservation of the Conservation of the American Black DuckAmerican Black Duck

A presentation by Patrick A presentation by Patrick GaskinGaskin

American Black DuckAmerican Black Duck

• Large dabbling duck of Large dabbling duck of the North Eastthe North East

• A species of special A species of special concernconcern

• Combined Combined conservation efforts conservation efforts between the US and between the US and Canada may have the Canada may have the numbers on the risenumbers on the rise

Background InformationBackground Information

• OrderOrder- Anseriformes- Anseriformes• FamilyFamily- Anatidae- Anatidae• Sub-familySub-family- Anatinae- Anatinae• TribeTribe- Anatini- Anatini• Anas rubripesAnas rubripes• Other namesOther names

– Canard noir (French) Andande sombrio Canard noir (French) Andande sombrio americano (Spanish)americano (Spanish)

DescriptionDescription

• Body is a dark blackish brownBody is a dark blackish brown

• Head and neck are lighterHead and neck are lighter

• Legs and feet are redLegs and feet are red

• White linings under wingsWhite linings under wings

• Blue speculum is Blue speculum is notnot bordered by white bordered by white– Similar to female Mallard and Mottled Duck at Similar to female Mallard and Mottled Duck at

a distancea distance

• Immature are similar to adultsImmature are similar to adults– Underparts more heavily streakedUnderparts more heavily streaked

Description continuedDescription continued

• Size: 54-59 cm (21-23 in)Size: 54-59 cm (21-23 in)

• Wingspan: 88-95 cm (35-37 in)Wingspan: 88-95 cm (35-37 in)

• Weight: 720-1640g (25.42-57.89 oz)Weight: 720-1640g (25.42-57.89 oz)

• Population about ½ millionPopulation about ½ million

• Voice is a raspy “quack”Voice is a raspy “quack”

Differences among the Differences among the gendersgenders• Male is slightly largerMale is slightly larger

• Bill colors differBill colors differ– Male has a yellow billMale has a yellow bill– Female has a green Female has a green

bill often with black bill often with black mottlingmottling

• Males legs are a Males legs are a brighter red than brighter red than femalefemale

Similar speciesSimilar species

• Female MallardFemale Mallard

Eclipse Male MallardEclipse Male Mallard

Mottled DuckMottled Duck

Mallard/Black Duck hybrid Mallard/Black Duck hybrid malemale

RangeRange

• Breeds: Eastern Canada Breeds: Eastern Canada and the North East USand the North East US

• Winters: Southern Winters: Southern Canada to the Gulf Canada to the Gulf Coast, as far west as Coast, as far west as IowaIowa– SE refuges especially SE refuges especially in TN and ALin TN and AL

• Most migrate along the Most migrate along the Atlantic FlywayAtlantic Flyway– but about 1/3 use the but about 1/3 use the

Mississippi FlywayMississippi Flyway

HabitatHabitat

• Breeds in a variety of wetland habitatsBreeds in a variety of wetland habitats– Salt marshes, beaver ponds, river islands Salt marshes, beaver ponds, river islands

and boreal bogsand boreal bogs•Often prefers wooded habitats (boreal forests Often prefers wooded habitats (boreal forests

and parkland ecotones)and parkland ecotones)

– Nest typically in upland locationsNest typically in upland locations

• Winters in salt water along coasts, but Winters in salt water along coasts, but also in a variety of freshwater areas also in a variety of freshwater areas inlandinland

Other info:Other info:

• Diet is diverseDiet is diverse– Higher in animal protein than many Higher in animal protein than many

other dabblersother dabblers•Mussels, snails, and gizzard shadMussels, snails, and gizzard shad

– Also grains and seeds as other dabblersAlso grains and seeds as other dabblers•Filter feeds at surface and also tips up in Filter feeds at surface and also tips up in

shallow watershallow water

Other info continued…Other info continued…

• Nest in vegetation in upland Nest in vegetation in upland locations (boreal forest and parkland locations (boreal forest and parkland ecotones)ecotones)– Nest is lined with downNest is lined with down– 1-17 eggs in clutch, typically 9-10 on 1-17 eggs in clutch, typically 9-10 on

averageaverage

What happened?What happened?

• Populations declined in the mid-20Populations declined in the mid-20thth centurycentury

• Several factors have contributed to Several factors have contributed to the declinethe decline

Reasons for population Reasons for population declinedecline

• Loss of habitat (both breeding and Loss of habitat (both breeding and non-breeding areas)non-breeding areas)

• Over-harvesting by huntersOver-harvesting by hunters

• Interbreeding with the Mallard Interbreeding with the Mallard

• Competitive disadvantages to Competitive disadvantages to MallardMallard– Mallards may take over some breeding Mallards may take over some breeding

spotsspots

What is being done?What is being done?

• Initially population counts and Initially population counts and surveyssurveys– Essential to measure the scale of the Essential to measure the scale of the

problem before proceeding with any problem before proceeding with any management optionsmanagement options

The Findings:The Findings:

• American Black Duck wintering populations American Black Duck wintering populations have been declining since 1955have been declining since 1955– This led to pressure to prohibit hunting of this This led to pressure to prohibit hunting of this

duckduck

• US government decreased the daily bag US government decreased the daily bag limit for this species in 1983limit for this species in 1983– Canadian government followed suit in 1984Canadian government followed suit in 1984

• Further tightened the harvest limits in 1989 and 1990Further tightened the harvest limits in 1989 and 1990

– Current daily bag limit in KY is 1 Black DuckCurrent daily bag limit in KY is 1 Black Duck

This didn’t accomplish all that This didn’t accomplish all that was hoped for:was hoped for:• Despite these measures, the Black Duck Despite these measures, the Black Duck

remains a source of concern due to:remains a source of concern due to:– Hunting pressureHunting pressure

• Some hunters mistake Black Ducks for female Some hunters mistake Black Ducks for female Mallards, or ignore possession limits Mallards, or ignore possession limits

– Habitat loss and degradationHabitat loss and degradation– Competition and hybridization with the MallardCompetition and hybridization with the Mallard

• However, since 1989, the average number However, since 1989, the average number of American Black Ducks killed by hunters of American Black Ducks killed by hunters has decreased by 26% in Canada, and by has decreased by 26% in Canada, and by 44% in the US44% in the US

Habitat loss and Habitat loss and degradationdegradation• Mid Atlantic coastal areas have been Mid Atlantic coastal areas have been

affected by ditch buildingaffected by ditch building– To control mosquito populationsTo control mosquito populations

• Coastal lagoon and housing developmentsCoastal lagoon and housing developments• Clearing and loggingClearing and logging

– Losses of forested wetlands decreases suitable Losses of forested wetlands decreases suitable breeding habitatsbreeding habitats

• Environmental contamination by pollutantsEnvironmental contamination by pollutants– Formerly affected by DDT and lead poisoningFormerly affected by DDT and lead poisoning

• DDT banned by US in 1971, and lead shot banned DDT banned by US in 1971, and lead shot banned twenty years latertwenty years later

Interbreeding with Mallards:Interbreeding with Mallards:

• Compounded by the introduction of captive-Compounded by the introduction of captive-raised Mallards into Black Duck breeding raised Mallards into Black Duck breeding rangesranges– Since 1940, 1.7 million game-farm Mallards have Since 1940, 1.7 million game-farm Mallards have

been released in American Black Duck rangesbeen released in American Black Duck ranges• Not only leads to increases in hybridization, but also to Not only leads to increases in hybridization, but also to

increases in competition for breeding sitesincreases in competition for breeding sites

• Leads to “diluted” stock of Black DucksLeads to “diluted” stock of Black Ducks– Decline of American Black Duck as a distinct Decline of American Black Duck as a distinct

speciesspecies

NAWMPNAWMP

• In 1986, the US and Canada joined In 1986, the US and Canada joined forces to institute the North forces to institute the North American Waterfowl Management American Waterfowl Management Plan (NAWMP)Plan (NAWMP)– Mexico signed on in 1988Mexico signed on in 1988

Main goal of NAWMPMain goal of NAWMP

• Restore waterfowl populations to Restore waterfowl populations to their 1970’s (1970-1979) winter their 1970’s (1970-1979) winter levelslevels– The urgency of restoring the Black Duck The urgency of restoring the Black Duck

led the NAWMP to set up the Black Duck led the NAWMP to set up the Black Duck Joint Venture (BDJV)Joint Venture (BDJV)•Between the US, Canada, and MexicoBetween the US, Canada, and Mexico

Black Duck Joint Venture Black Duck Joint Venture mandate:mandate:

• Facilitate and coordinate the Facilitate and coordinate the gathering of informationgathering of information

• Improve our knowledge of the Improve our knowledge of the speciesspecies

• Guide conservation and manage Guide conservation and manage most decisionsmost decisions

Three programs were Three programs were established under the venture:established under the venture:

•Survey programSurvey program

•Banding programBanding program

•Research programResearch program

Survey ProgramSurvey Program

• The survey data has been analyzed The survey data has been analyzed to determine population trends and to determine population trends and changeschanges– Birds are counted from aircraftBirds are counted from aircraft– Count all pairs and lone males in a Count all pairs and lone males in a

breeding habitatbreeding habitat– The numbers are expressed as breeding The numbers are expressed as breeding

pairspairs

American Black Duck Trends of American Black Duck Trends of Breeding Pairs since 1990Breeding Pairs since 1990

Banding ProgramBanding Program

• Coordinated by the Atlantic Flyway Coordinated by the Atlantic Flyway Eastern Cooperative Banding Eastern Cooperative Banding Agreement under the BDJV Agreement under the BDJV

• Determine the relative distribution of Determine the relative distribution of kills and sport harvest rateskills and sport harvest rates– Used to calculate the survival rates for Used to calculate the survival rates for

the populations sampledthe populations sampled– These can be done using program These can be done using program

ESTIMATE or othersESTIMATE or others

Research ProgramResearch Program

• Identify the causes for Black Duck Identify the causes for Black Duck population declinespopulation declines

• Identify factors that may help the Identify factors that may help the species to recoverspecies to recover– Attempt to determine the relative Attempt to determine the relative

importance of the factors influencing importance of the factors influencing American Black Duck numbers and American Black Duck numbers and population dynamicspopulation dynamics

At the beginning of the At the beginning of the program:program:

• Research efforts focused on Research efforts focused on measuring annual American Black measuring annual American Black Duck productivity compared to that Duck productivity compared to that of Mallardsof Mallards

More recently the priority has been on More recently the priority has been on the relation between:the relation between:

• Variation in recruitment rates and Variation in recruitment rates and landscape configurationlandscape configuration

• Habitat productivityHabitat productivity

• The presence of the MallardThe presence of the Mallard

• The current focus of the program is The current focus of the program is on Adaptive Harvest Management on Adaptive Harvest Management related studiesrelated studies

Adaptive Harvest Management Adaptive Harvest Management (AHM)(AHM)

• Seeks to reach a long-term harvest Seeks to reach a long-term harvest objectiveobjective– Decisions being annual harvest Decisions being annual harvest

regulations (quota)regulations (quota)

Tasks of AHMTasks of AHM

• Using the analyses completed under Using the analyses completed under previous work orders, develop a model previous work orders, develop a model set for use in adaptive optimizationset for use in adaptive optimization

– Emphasis devoted to initiating a very simple Emphasis devoted to initiating a very simple AHM modelAHM model• Exploring the consequences of finer vs. coarser Exploring the consequences of finer vs. coarser

resolution in objective, decision space and state resolution in objective, decision space and state space, and of alternative model weightingsspace, and of alternative model weightings

• Working with BDJV and other Working with BDJV and other stakeholders, develop and stakeholders, develop and incorporate objective functionsincorporate objective functions

– Formulation of a suitable objective Formulation of a suitable objective function is criticalfunction is critical• A matter for resolution among managers A matter for resolution among managers

and policy makersand policy makers

– Concept of “sustainability” is at the Concept of “sustainability” is at the core of most natural resource core of most natural resource managementmanagement

• Working with BDJV and other Working with BDJV and other stakeholders, develop alternativesstakeholders, develop alternatives– Joint Black Duck-Mallard objectiveJoint Black Duck-Mallard objective

• Joint consideration of harvest regulations for Joint consideration of harvest regulations for each specieseach species

– Restrictive for both speciesRestrictive for both species– Liberal for both speciesLiberal for both species– Restrictive for one, liberal for the otherRestrictive for one, liberal for the other

• Definition of state space and Definition of state space and resolution of monitoring effortsresolution of monitoring efforts– Important state variables to considerImportant state variables to consider

•Estimates of breeding (wintering, or both) Estimates of breeding (wintering, or both) Black Duck populationsBlack Duck populations

•Estimate of breeding habitat conditionsEstimate of breeding habitat conditions

•Estimates of breeding Mallard populationsEstimates of breeding Mallard populations

• Evaluate the potential impacts of Evaluate the potential impacts of model resolution and management model resolution and management scale on optimal decision making, scale on optimal decision making, with respect to gain in objective with respect to gain in objective value, vs. costs Evaluate the value, vs. costs Evaluate the potential impacts of model resolution potential impacts of model resolution and management scale on optimal and management scale on optimal decision making, withdecision making, with – Reconfigure models to allow for Reconfigure models to allow for

multiple populations and stratified multiple populations and stratified objectives and decision makingobjectives and decision making

– Evaluate the consequences of Evaluate the consequences of spatial stratification onspatial stratification on• The ability to meet resource objectivesThe ability to meet resource objectives• The tradeoffs in terms of complexity and costs of The tradeoffs in terms of complexity and costs of

finer vs. coarser scale managementfiner vs. coarser scale management

• Depending on the results of 1-5, Depending on the results of 1-5, develop a working adaptive develop a working adaptive management protocol for Black Ducksmanagement protocol for Black Ducks– Possible joint Black Duck-Mallard protocolPossible joint Black Duck-Mallard protocol

•Recommend one or more forms for the Recommend one or more forms for the objective functionobjective function

•Recommend sets of decision alternativesRecommend sets of decision alternatives•Develop a working model set and optimization Develop a working model set and optimization

procedureprocedure•Recommend the scale and intensity at which Recommend the scale and intensity at which

relevant state variables and other parameters relevant state variables and other parameters should be measuredshould be measured

Conclusions:Conclusions:

• Combined conservation efforts of the US Combined conservation efforts of the US and Canada may have numbers on the riseand Canada may have numbers on the rise– The BDJV graph showing breeding pair The BDJV graph showing breeding pair

distribution trends shows a higher population distribution trends shows a higher population of breeding pairs since 1994of breeding pairs since 1994• Populations still experience rising and falling trends, Populations still experience rising and falling trends,

but they remain higher than the low population count but they remain higher than the low population count of 1994of 1994

• The steady decline in breeding pairs from 1990-1994 The steady decline in breeding pairs from 1990-1994 looks to be haltedlooks to be halted

• No solid evidence of major decreases in quality or No solid evidence of major decreases in quality or quantity of breeding habitat for Black Ducks since quantity of breeding habitat for Black Ducks since the late 1980’sthe late 1980’s– Except in specific areas, such as those disrupted by Except in specific areas, such as those disrupted by

hydroelectric projectshydroelectric projects– An increase in beaver populations may be helping to An increase in beaver populations may be helping to

create more wetland breeding habitatcreate more wetland breeding habitat

• Populations are currently steadyPopulations are currently steady– But only about ½ as many Black Ducks as there were in But only about ½ as many Black Ducks as there were in

the early 1950sthe early 1950s

• Still face problems with Mallard competition and Still face problems with Mallard competition and hybridizationhybridization– Adaptive harvest management techniques could be Adaptive harvest management techniques could be

employed to ease the hunting pressure on American employed to ease the hunting pressure on American Black Ducks, while working to control Mallard Black Ducks, while working to control Mallard populations in areas shared by the two speciespopulations in areas shared by the two species

SourcesSources

• Canadian Wildlife Service (CWS), Quebec Canadian Wildlife Service (CWS), Quebec Region Region www.lavoieverte.qc.ec.gc.ca/faune/sauvagine/html/historic.htmwww.lavoieverte.qc.ec.gc.ca/faune/sauvagine/html/historic.htmll

• Cornell Lab of OrnithologyCornell Lab of Ornithologywww.birds.cornell.eduwww.birds.cornell.edu

• Hinterland Who’s WhoHinterland Who’s Whowww.hww.ca.comwww.hww.ca.com

• Black Duck Adaptive Management Working Black Duck Adaptive Management Working GroupGrouphttp://coopunit.forestry.uga.edu/blackduck/overview.htmlhttp://coopunit.forestry.uga.edu/blackduck/overview.html