Doug Leier: Spring survey of North Dakota breeding ducks provides insight into population trends – Grand Forks Herald

Doug Leier is an outreach biologist for the North Dakota Game and Fish Department. Contact him at [email protected]

WEST FARGO – When it comes to wildlife science and surveys, the accumulation of data over time gives biologists and wildlife managers more confidence to compare numbers from previous years and develop a population index accurate.

We are not comparing a census count of each individual. The index compares numbers from previous counts, in past years over time. The resulting data provides insight into demographic trends. Then, by comparing habitat and other factors and conditions, we are able to get a broader overview of a species’ status.

The North Dakota Game and Fish Department’s 75th Annual Spring Breeding Duck Survey, conducted in May, showed an index of nearly 3.4 million birds, up 16% from last year. The index was the 23rd highest on record and is 38% above the long-term average (1948-2021), said Mike Szymanski, supervisor of migratory game birds for Game and Fish in Bismarck.

Mike Szymansky

Contribution / North Dakota Game and Fisheries Department

Indices for most individual species except green-winged teal, gadwall, wigeon and blue-winged teal increased from 2021. Mallards increased by 58% compared to 2021 and represented the 25th highest number on record. Ruddy duck index increased by 157%, shoveler and pintail increased by 126% and 108%, respectively, and other increases ranged from 4% for scaup to 69% for duck. canvas back. Decreases from the 2021 index were seen for Green-winged Teal (-42%), Gadwall (-36%), Eurasian Wigeon (-10%) and Blue-winged Teal (- 4%).

“It’s important to note that some of our increases in statewide species numbers may not reflect larger-scale population trends, particularly for pintails,” Szymanski said. “The abnormally wet conditions in the state likely contain a higher percentage of breeding pintails than normal. We are coming out of a very dry year that has resulted in low range-wide breeding for many species.

The number of temporary and seasonal wetlands was significantly higher than last year as figures show the Spring Water Index rose by 616%, the largest single-year increase ever for the ‘investigation. The water index is based on basins with water and does not necessarily represent the amount of water contained in the wetlands or the type of wetlands represented. Steady rainfall and cool weather preceding the survey left a lot of water on the landscape in ditches and intermittent streams.

“As well as being our 75th consecutive survey year, this was an interesting survey as we’ve been back and forth between wet and dry conditions over the past two years,” Szymanski said. “We actually had our second highest wetland index in the state, which is largely made up of water that dries up pretty quickly. But ponds that are important for brood-rearing habitat have also rebounded well.

“A lot can change between May and the hunting season, so we’ll have some additional insights into our July Brood Index and our September Wetland Count,” he added. “But duck production should be a bit better this year than last year due to a bigger breeding effort. However, we continue to lose grass in upland nesting sites which will decrease the breeding potential of ducks in the state. Despite the expected low production of Canada geese this year due to harsh conditions in April, we had record numbers of geese on the breeding grounds, so hunting opportunities for these birds should be quite good again this year.