Early spring waterfowl surveys present mixed picture
Variable spring habitat conditions observed in the United States and Canada present a mixed picture for the fall 2009 waterfowl seasons in Wisconsin, according to the state waterfowl biologist.
Preliminary information shows areas ranging from very good wetland conditions to very dry. Wildlife managers will have a better understanding of what impact these conditions had on actual breeding waterfowl numbers when they finish compiling and analyzing spring waterfowl breeding surveys.
Three primary sources of information on yearly waterfowl breeding conditions are used to determine the fall season structure for Wisconsin, according to Kent Van Horn, Department of Natural Resources migratory waterfowl biologist.
“We’ve completed the annual Wisconsin Breeding Waterfowl Survey, which is very important since a large proportion of the ducks harvested in Wisconsin are raised in Wisconsin,” Van Horn said.
The other two sources are a cooperative survey of Canada geese, the Mississippi Valley Population (MVP) Breeding Survey by the Ontario Ministry of Natural Resources, and a U.S. Fish and Wildlife Service breeding waterfowl survey for the northern U.S., Canada and Alaska.
DUCKS
Waterfowl breeding areas in Canada this spring had mostly fair to good conditions with smaller areas of excellent and poor habitat. Waterfowl breeding is expected to be good overall in Canada.
P
recipitation and wetland habitats
in the U.S. prairies for 2009 were mostly good to excellent with significant flooding in large areas.
In Wisconsin, wetland conditions were highly variable with average to wet conditions in the southern part of the state and drought conditions in northwestern Wisconsin. Breeding and brood-rearing habitat in southern Wisconsin is expected to be good in 2009 but poor in northern Wisconsin.
The four most abundant ducks in Wisconsin’s fall hunting harvest are mallards, wood ducks, green-winged teal and bluewinged teal. Van Horn notes that many of the ducks harvested in Wisconsin come from birds that breed in Wisconsin, in contrast to other states in the flyway that rely more heavily on birds raised in the prairies or boreal forests of Canada.
T
he 2009 total Wisconsin
breeding duck population estimate of 502,416 is down 20 percent from 2008, but 16 percent above the long-term mean (36 years).
The difference in the total duck estimate between 2008 and 2009 is largely explained by unusually high 2008 estimates for the bluewinged teal and "other duck" components which returned to more normal levels in 2009.
Overall breeding duck survey results indicate a healthy, relatively stable population of breeding ducks in Wisconsin experiencing normal annual fluctuations.
“These are population estimates – not exact counts – so changes of near 20 percent up or down in the estimates each year may not reflect any real change in the actual population,” Van Horn said.
The mallard population estimate of 200,497 is a 6 percent increase over 2008 and 10 percent above the long-term mean. Mallards constitute nearly 40 percent of the overall state duck harvest in Wisconsin.
The blue-winged teal breeding population showed a 37 percent decrease from 2008 but was just 2 percent below the long-term mean.
“We continue to have a concern for sustainable breeding habitat for both mallards and breeding blue-winged teal in Wisconsin,” Van Horn said.
“While our conservation efforts of the past have been successful, the threats to decreased grassland nesting habitat for blue-winged teal and mallards have increased with changes to the federal farm bill in 2008 that have led to withdrawals from the Conservation Reserve Program.”
The population estimate for wood ducks was 10 percent below 2008 but 51 percent above the long-term mean. Current trend analysis for wood ducks in Wisconsin suggests that the long-term increase in the breeding population has leveled off near 120,000.
CANADA GEESE
There are two populations of Canada geese that represent most of the geese harvested in Wisconsin.
“There are two different populations most of the geese in Wisconsin during the regular fall hunting season and our harvest is about 50 percent from each of these populations during the regular hunting seasons,” Van Horn said.
One population, called resident giant Canada geese, nests in Wisconsin. The statewide breeding Canada goose population estimate of 148,293 is up 27 percent from 2008 and 84 percent above the long-term mean. Van Horn says the cause of the higher estimate in 2009 is unclear, but could represent variation in the survey or a real population increase.
The second Canada goose population is the Mississippi Valley Population, which is made up of birds that nest along the coast of Hudson Bay and migrate through Wisconsin.
The estimated 2009 breeding population of MVP Canada geese was 239,631 down from 305,191 in 2008 and was 35 percent below the 1989-2008 average. In contrast, the 2009 total spring population estimate was 518,232, below that of 2008 (626,358) but only 3 percent below the 1989-2008 average.
The total population includes the breeding birds as well as nonbreeders and those whose breeding attempts failed.
“These preliminary numbers indicate a year of waterfowl numbers with a mix of good and bad news, but we will not know for sure what these mean for seasons until after the Mississippi Flyway Council meeting at the end of July,” Van Horn said.
The Mississippi Flyway Council is made up of waterfowl specialists from the states of Alabama, Arkansas, Illinois, Indiana, Iowa, Kentucky, Louisiana, Michigan, Minnesota, Mississippi, Missouri, Ohio, Tennessee and Wisconsin, and the Canadian provinces of Manitoba, Ontario, and Saskatchewan within the Mississippi Waterfowl Flyway.
The council will meet later this summer to advise the U.S. Fish and Wildlife Service (USFWS) on waterfowl conditions before the federal agency establishes a framework under which states and provinces can set waterfowl hunting seasons.
Following the flyway council meeting and after the USFWS sets a season framework, public hearings on Wisconsin’s proposed waterfowl seasons will be held in August. The finalized Wisconsin seasons will be set by the state
