Migratory phenology and patterns of American woodcock in central North America

It is not uncommon for American woodcock to encounter winter conditions during their spring migration.

By Joseph D. Moore, David E. Andersen, Tom Cooper, Jeffrey P. Duguay, Shaun L. Oldenburger, C. Al Stewart, David G. Krementz

Autumn in the northern USA and Canada signals an important time in the life cycle of American woodcock (Scolopax minor) for both the bird and the hunter. Decreasing day length triggers the onset of migration for woodcock and coincides with the start of woodcock hunting. Fast forward three-and-a-half months or so and increasing day length signals that it is time for woodcock to head back north from their wintering grounds in the southern U.S. to their northern breeding grounds. Understanding migration patterns is important in the management of this upland gamebird species for making decisions related to harvest seasons and in understanding factors related to the migration of this short-distant migrant. To this end, we fitted 73 woodcock with satellite-based tracking devices during 2013–2016. Twenty-two of these woodcocks were fitted with tracking devices on the northern portion of their range (Michigan, Minnesota, and Wisconsin), 50 on their wintering grounds in Louisiana and Texas and one during spring migration in Arkansas. We monitored woodcock during autumn migration in 2013, 2014, and 2015 and we monitored woodcock during spring migration in 2014, 2015, and 2016.

Spring migration of American woodcock with satellite-based tracking devices during 2014, 2015, and 2016.

Woodcock during our study had a mean autumn departure date of 3 November and juvenile female woodcock began migration later than adult female woodcock.  These results provide a basis for comparing current harvest seasons with presence of migrating woodcock during autumn, and provide insight into differential harvest of migratory vs. local woodcock on breeding areas.

Woodcock in our study made a higher number of close-together migratory stopovers during spring migration than during autumn migration, resulting in spring migration (53 days) being of longer duration than autumn migration (31 days). This strategy of using close-together migratory stopover sites may allow woodcock to assess local environmental and phenological conditions and thus adapt their migration rate, something that may allow them to arrive at their destinations when conditions are conducive for attracting mates and breeding.

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