This winter’s unusually warm weather is continuing to be a major factor across much of North America this spring and is resulting in an abnormally early migration for many birds. Different bird species are responding to the unusual conditions in diverse ways.
Short- and medium-distance migrants primarily winter in the southern U.S. or Mexico and travel north in short flights that are triggered by good weather and favorable wind directions. Both of these conditions have persisted for the past few weeks and have triggered many of these migrants to head north early.
Short distance migrants like Eastern and Say’s Phoebes, Pine Warblers and American Robins are arriving back on their nesting grounds weeks ahead of their normal schedules.
Mid-distance migrating birds, such as the Ruby-throated Hummingbird and Louisiana Waterthrush are also showing strong signs of some early migration activity.
Long-distance migrants coming from Central America, South America or the Caribbean are not expected to show any early migration movements. These migrants fly in long nonstop flights, and their departure is primarily triggered by increasing periods of sunlight each day. Weather is not a factor and they will migrate on the same schedule as usual.
But, what does this mean for birds that visit our backyards?
Here are some potential impacts:
? Local, winter resident birds such as Slate-colored Juncos, White-crowned, White-throated & America Tree Sparrows are likely to leave for their northern breeding grounds weeks earlier than normal.
? Short- and medium-distant migrants may arrive back earlier than normal. They may include Chipping Sparrows, Hummingbirds, Red-winged Blackbirds, Cowbirds and Grackles.
? Long-distance migrants such as Orioles, Scarlet Tanagers, Rose-breasted Grosbeaks & Indigo Buntings should be arriving within the normal range of migration return dates.
What birds are you seeing move earlier than usual?