Risk and Reward for the American Woodcock: the Energy Balance of an Early Migrant in a Late-Winter Storm
By Andy Weik, RGS & AWS Regional Wildlife Biologist
In the snowy North, we look forward to the arrival of woodcock and red-winged blackbirds as the first signs of spring. Woodcock are among the first – if not THE first – ground-nesting birds to begin nesting. Woodcock really push the envelope as they migrate north from southern wintering grounds, moving into open ground along spring seeps, streams and south-facing slopes in search of earthworms and grubs as snow cover recedes. In years when winter segues smoothly into spring, the early-arriving woodcock is rewarded with sufficient food and mild weather to hatch its four-egg clutch within a month of arriving on the breeding range, before most of its predators have extra mouths of their own to feed.
But this year in the Northeast we had spring conditions in the heart of winter. Mild February weather and bare ground enticed woodcock to arrive back in parts of the Northeast up to a month or more earlier than usual, and freeze-ups and snow-falls were brief enough to pose little problem to these hardy birds. Although woodcock hens may not have found enough food to develop eggs and commence laying, woodcock likely were able to find enough food to maintain weight, in other words to not expend more energy than they took in. Woodcock that had arrived on their nesting areas were in a holding pattern until spring arrived and food became more abundant.
And then in March came a sharp cold snap followed within a few days by storm Stella, dumping significant snow across the region. Snow-free, frost-free cover – feeding access – became very limited. Already stressed by the energy demands of migration, woodcock had a hard time finding food, and their energy budgets turned negative. Many lost weight, some died. During the second day of storm Stella I got a call from a worker at the Newark, New Jersey airport reporting several dead or weakened woodcock, and a gentleman in Connecticut emailed asking how to care for and release a weakened woodcock he had picked up. Social media sites lit up with pictures and video of woodcock feeding or huddled in snow-free gaps along small brooks or next to houses. A wildlife rehabilitator in NYC reported a sharp uptick in emaciated and dead woodcock, and one in Maine also reported receiving numerous emaciated woodcock. The Raptor Trust (Millington, NJ) posted on Facebook “Winter Storm Stella – we admitted more Woodcocks at The Raptor Trust than in the entire 2016 calendar year.”
So, what does it all mean in the big scheme of things? Late winter or spring snow storms that stress and kill woodcock are nothing new. The most memorable for me was 2007, when a Nor’easter hit the Northeast hard in the middle of April, causing widespread flooding and dropping several inches of snow on coastal Maine. For eastern Maine, this was one of 3 or 4 significant snow storms that maintained nearly complete snow-cover for the month of April, after many woodcock had returned in March. The woodcock singing male count at Moosehorn National Wildlife Refuge dropped by 41 percent that spring, and surveys on the Refuge indicated minimal woodcock production. It took three years for Moosehorn’s woodcock population to recover to pre-2007 numbers; Maine’s statewide singing male count dropped that year also, but rebounded one year later.
This year, the mild weather and lack of snow in February was more significant than storm Stella in March. In a typical year, this snow storm would not have generated nearly the discussion among timberdoodle enthusiasts, as typically the landscape would be snow-covered in February and most of the birds would not have been back yet; however, birds were back and the snow was significant and widespread. The effect of a “Stella” will depend largely on two factors – weather that follows (duration of freezing temperatures, a warm spell, additional snow storms, rain, etc), and the proportion of woodcock that have migrated north vs. those that were still south of the storm. We’ve learned through research, such as the recent satellite telemetry migration study, that not all woodcock have the same migration strategy – they follow varying routes to the same destination, and some arrive as early as possible whereas others lag behind. Now we can look forward to the results of local and regional woodcock singing ground surveys as we keep an eye on the activity of the little russet fellows in our home coverts.
For more info on American woodcock ecology
For info Ruffed Grouse Society and American Woodcock Society habitat programs
Become a member of the American Woodcock Society: www.ruffed.org