(Reprinted from the Spring 2023 issue of New Hampshire Bird Records.)

Spring is migration time and different birds arrive at different times. Huge concentrations can sometimes occur, but it’s often hard to know where or when. Here are a few events that often highlight April and when to watch for them.

• Winter visitors like American Tree Sparrows and redpolls or siskins are usually gone by April. Chipping Sparrows, the tree sparrow look-alike, arrive around mid-April.
• In early April watch for Hermit Thrush to arrive. Veerys and other thrushes arrive later, usually in May.
• Ruby-crowned Kinglets begin to arrive the second week of April. Their song can be confused with Common Yellowthroat, which doesn’t arrive until the beginning of May and Carolina Wren.
• Watch for Broad-winged Hawks in the third week of April, especially on a warm, south wind. You can follow their progress north in eBird to know when they are getting close.
• The earliest warblers arrive mid-month: Pine, Palm, and Yellow-rumped, followed quickly by Louisiana Waterthrush. The first warblers of the main May wave often appear at the very end of the month, including Black-and-white, Northern Parula, and Black-throated Green Warblers. See the article by Steve Mirick on the timing of Louisiana and Northern Waterthrushes in the Spring 2014 issue of New Hampshire Bird Records.
• Inclement weather in late April can bring fallouts of migrating Horned and Red-necked Grebes as well as winter sea ducks such as Red-breasted Mergansers and Long-tailed Ducks. Look for them on large lakes such as Newfound, Spofford, or Lake Winnipesaukee.
• Tree Swallows are the first swallows to return in early April (and often late March), followed by Northern Rough-wingeds. Look for huge flocks over waterbodies if there’s a cold spell or rainy weather. The Merrimack and Connecticut Rivers, waste treatment plants, and even local ponds can provide quite a concentration.
• House Wrens begin to trickle in during the last few days of April. Wren chatter before that is likely to be Carolina or Winter Wren.

New Hampshire Bird Records is now available in digital format free to all NH Audubon members. (Not a member yet? Join here!) All members receive an email with a link to the current issue. Printed copies are available to members for an additional fee that covers the cost of printing and postage. Details are on the New Hampshire Bird Records website.

Photo: Broad-winged Hawk by Len Medlock.