Migration of birds to Maine was noticeably lower this spring than on average. Pat Sullivan/Associated Press

Just how active was migration this spring? Many thanks to Brad Woodward for sending in a question asking if we have data about this spring. He (as did other birders) felt it was slow for birding. Turns out it actually was. Let’s look at the data and possible reasons for the low numbers.

Many of the birds that have returned to Maine to breed this summer are nocturnal migrants, especially songbirds like warblers, and thrushes. A joy for birders in the spring, albeit one that results in sleep deprivation, is to head out early in the mornings and look for these migrants as they make landfall and forage through the early hours. Sometimes there are lots of birds, and other times, often when conditions aren’t favorable, there are few to no new birds.

Weather conditions, especially the wind direction, play a big role in when birds will migrate. A favorable tailwind from the south will help usher birds north. A northerly breeze will often keep birds grounded to our south, where they’ll keep fueling up before they have the opportunity to make the jump north. Our spring, especially during the second and third weeks of May when we should have been seeing the peak of bird movements, was plagued by evenings with northwest winds. This resulted in many nights with few birds moving, and mornings with little to see (except for just a handful of days when the winds shifted and that backlog of birds pushed through in astounding numbers).

We can use BirdCast – a website that forecasts bird migration based on weather and radar information – to review what happened each night and see when some of these peaks were. Perhaps the day that sticks out most to me was Monday, May 16. I had been leading bird walks at Evergreen Cemetery the whole week before, and it was admittedly slow, but the floodgates opened on Monday and birds were practically dripping from trees. According to BirdCast, over 2.2 million birds passed over Maine that night. Interestingly, the radar station in Gray was lit up with birds, while the station in Caribou was quiet – a bit of evidence that those birds weren’t just passing through, many were dropping in. The other amazing day was Sunday, May 22, when an astonishing 16.8 million birds crossed over Maine the evening before.

These nightly highs stand out among the many lows, but it is also interesting to see how that averaged out. BirdCast is also able to calculate the number of “total birds crossed,” which is an estimate of the total number of individual birds that crossed over Maine during the spring migration. The estimate for this year was 131.4 million birds. Compared to the “historic average,” which is closer to 160 million, that is noticeably low.

It is easy to speculate why overall numbers would be down, though it was a challenging spring for birds to get up here. They face many obstacles beyond bad weather, from outdoor cats to the “invisible” buildings (as in, glass windows!) they strike. I will end by saying it is uplifting to see so many birds that are here now nesting successfully. From geese with goslings to waxwings building nests now, the next generation is on its way.

KATAHDIN WOODS AND WATERS

As we head into peak tourism season in Maine, we get a lot of questions from visiting birders about places to go to look for birds. Typically people plan on visiting a general area, but need help finding specific places to look for birds and other wildlife. An increasingly popular destination, for both tourists and Maine-based birders, is the recently established Katahdin Woods and Waters National Monument. To help shed light on the best places to go here, and to encourage all of you to see the wonders Woods and Waters hold, I asked my colleague Nick Lund to share some tips on where to go and what to see.

Here are his recommendations:

Katahdin Woods and Waters National Monument provides convenient access to the birds of Maine’s great North Woods. The 87,000 acres of forest, mountains, and waterways in the monument host more than 100 bird species. Spring and summer see the returns of dozens of species of migrant songbirds that breed throughout the monument. Things are quieter in winter, but hearty and sought-after boreal specialties remain, including spruce grouse, boreal chickadee, and Canada jay. Most of the best birding sites in the monument can be accessed by a short trail or from gravel roads, though birders should take care to yield to trucks in both directions, and never park in the road or around blind corners.

Loop Road – Sandbank Campsite: Bird the wetlands and boreal forests around the campground. More than a dozen species of warbler may be seen and heard here in summer, and look year-round for boreal specialties like spruce grouse, black-backed woodpecker, and boreal chickadee.

Loop Road – Deasey Ponds: Park at the Deasey Ponds Trailhead for a 1.2-mile round-trip walk to the Deasey Ponds. Pass through a mix of forest types, keeping an eye out for ruffed and spruce grouse, warblers, and finches. The ponds themselves may hold American bittern, wood ducks, common loons, and other water birds.

Loop Road – Lynx Pond: Just past Mile Marker 2 is parking for the short, ADA-accessible Lynx Pond Trail. The habitat here is good for migrant songbirds, including yellow-bellied and olive-sided flycatchers, and the pond has hosted waterfowl including American black duck, common goldeneye, ring-necked duck, and hooded merganser.

Loop Road – The Overlook: Abundant birdlife may be the only distraction from views at this spectacular overlook just after Mile Marker 6. Elusive mourning warblers may be heard singing from the brambles in the meadow, and eagles, hawks, and vultures may be seen soaring over the treelines. Nearby vistas along the Loop Road are also rich in songbirds.

Loop Road – Barnard Mountain Trail: The moderate, 4-mile out-and-back Barnard Mountain Trail begins from a parking area just before Mile Marker 12. Birders will cross Katahdin Stream and pass through a variety of habitats with chances at dozens of species of breeding and resident birds before summiting with a dazzling view of Katahdin to the west.

Lunksoos Campsites: A boat launch and campground near the historic Lunksoos Camps provide an opportunity for waterfowl like hooded merganser and lowland forest birds like blue-headed and red-eyed vireo, northern waterthrush, northern parula, and yellow warbler.

Seboeis Unit: The dirt roads of the Seboeis Unit, east of the Penobscot River accessed off Waters Road, provide unparalleled backcountry birding. Follow your eyes and ears to find dozens of species of warblers, sought-after species like black-billed cuckoo, Philadelphia vireo, least bittern, and many others.

North Gate area: A number of trails begin at the North Gate, just south of Grand Lake Matagamon (including groomed cross-country ski trails for winter birders). Follow the river for as long as you please, looking for breeding warblers, bald eagles, spotted sandpipers, ruffed grouse, and numerous resident finch species.

Do you have a nature question for Doug? Email questions to ask@maineaudubon.org and visit maineaudubon.org to learn more about backyard birding, native plants, and programs and events focusing on Maine wildlife and habitat. Doug leads free bird walks on Thursday mornings, 7 to 9 a.m., at the Gilsland Farm Audubon Sanctuary in Falmouth.