As we continue to transition into winter, many wildlife species are watching food supplies dwindle around them.  Flowers have been done blooming for a long time, and now even their seeds are starting to disappear.  A few hardy insects are still around, but most have either died off or have found a comfortable place to spend the winter.

The seeds on this stiff sunflower (Helianthus pauciflorus) seed head are nearly gone. Birds likely got most of them, though wind may have knocked some off as well.

Sunflower seeds are a very attractive late fall/winter food source for many wildlife species, including many birds.  During our fall seed harvest each year, we definitely notice the impact of bird foraging – especially if we wait a little too long to gather seeds.  Large flocks of migrant birds can quickly deplete a stand of sunflowers of their seeds.  That can be frustrating for tardy prairie ecologists, but has bigger implications for resident prairie animals that depend upon those seeds for winter survival.

These annual sunflowers (Helianthus annuus) have already lost all of their seeds, though opportunistic scavengers might still find some on the ground beneath the plant.

Fortunately for resident wildlife, migrant birds don’t get all the sunflower seeds, so at least some are left for winter foragers.  When snow covers the ground, sunflowers and other plants that still hold seeds become particularly important for wildlife.  Some animals have already built up caches of stored seeds to eat when snow covers the ground, but other species – especially birds – have to make do with what’s sticking out above the snow.  It’s easy to see which plants have the best food supply by looking at the tracks in the snow around them!

Both small mammals and birds were foraging around these annual sunflowers in the snow.  Birds (and maybe some small mammals?) can get the seeds directly from the top of the plant, but others pick fallen seeds right off the snow. (2009 photo)