Summer
Kent McFarland
With nice weather finally (finally?) upon us, many are turning their attention to outdoor adventure. While out exploring, may come across these early summer sights: montane birds at the trailhead or White Bog Orchids in a marsh or bog. Or wildlife may come to you, with a colony of house bats and their pups! This June's guide gives you insight into their behaviors and life history.
By Jason Hill
It’s a sunny day in early June, and your plan is to beat the I-93 summer crowds with a hike up the Franconia Ridge in the White Mountains of New Hampshire. But as you ascend, you reach a point where the trail disappears under a monorail of packed snow. You stumble and post-hole every few steps, the microspikes you brought effectively worthless. You laugh out loud, throw in the towel, and retreat to the safety of the lower elevations and some dry socks.
If you notice a Bicknell’s Thrush sitting quietly in the hardwood understory around the parking lot, you might think you’ve detected it on its spring migratory return up the mountain. But what if it’s already been up… and come back down?
Each May, long-distance migrants like Yellow-bellied Flycatcher, Bicknell’s Thrush, and Blackpoll Warbler return to New England to breed in the spruce-fir forests that cap our highest peaks after overwintering thousands of miles away in the Caribbean and Central or South America. You might have seen one in your backyard in May, as Mike Hallworth wrote in our May Field Guide.
Now, there’s growing evidence that montane birds sometimes do what we do on a weekend hike: move up and down the slopes.
While altitudinal migration is typically discussed in seasonal terms—birds heading uphill to breed and downhill to overwinter—short-term or daily elevational movements are less well known, but potentially just as important. In Hawaiʻi, where I studied montane honeycreepers, we’d gather on a volcanic outcropping at the end of the day and watch birds flying above the canopy, heading to lower forest far below. The likely reason: warmer nighttime temperatures and richer foraging, improving energy conservation and early-morning food access. A 2017 study described this behavior as essential to their survival—but not without tradeoffs. At lower elevations, honeycreepers are more exposed to avian malaria carried by mosquitoes.
Here in Vermont, VCE’s Kent McFarland observed radio-tagged Bicknell’s Thrushes abandoning their high-elevation habitat during late spring snowstorms—retreating downslope into hardwood forests where they do not breed, likely to wait out the conditions.
Other recent research in the Alps supports this pattern, finding that Northern Wheatears equipped with pressure-sensitive tags regularly left their territories. One wheatear moved about 1,000 meters downslope from its breeding territory on multiple occasions in response to a snow storm, and all four birds in the study moved 50 to 200 meters upslope every night to roost outside of their territories, possibly to reduce predation risk or seek warmer microclimates. An earlier 2021 study, also in the Alps, found that birds adjusted elevation daily in response to snow cover, particularly early in the breeding season.
These evolutionarily adaptive movements—daily (or even just lasting hours at a time), flexible, and weather-driven—are likely more widespread than we realize. Yet they’ve only been formally documented in a handful of species. If montane birds rely on lower elevation refugia during poor weather or food scarcity, it could have important implications for how we conserve these species across the full elevational gradient.
So when you’re out on a hike this June, keep a lookout for birds that are far below their expected breeding grounds. A Fox Sparrow at the trailhead isn’t lost, and it’s not a ‘late bloomer.’ She may already have been up to the top and back again, flexing her evolutionary muscles in response to a dynamic mountain environment.
You might take it as a reminder to pack your snowshoes.
By Laura Costello
If I told you I saw an orchid on a hike, you might think first of the beautiful Pink Lady’s Slipper (Cypripedium acaule) that adorns Vermont forest floors in May and June. Many mistakenly believe it is New England’s only native orchid, but in fact, we have almost 50 wild orchid species in Vermont.
Some are extremely rare, but you might spot one fairly common species in late June or July: the White Bog Orchid (Platanthera dilatata). Also known as bog candle, it grows in a wide variety of wet environments across North America. In Vermont, it’s found from roadside ditches high on Mount Mansfield to lowland marshes, fens, and bogs across the state. When many White Bog Orchids bloom together, the dense spikes of sweet-smelling, pure-white flowers put on quite a show.
The orchid family has some of the most interesting pollinator relationships in the plant world. Some are extreme specialists, relying entirely on a single insect species. One orchid from Madagascar, known as Darwin’s Orchid (Angraecum sesquipedale), has a foot-long nectar spur! Charles Darwin famously predicted there must be a moth that had co-evolved a long enough tongue to drink nectar from and pollinate it, and 40 years later he was proved right. Other orchids rely on deceiving or trapping their pollinators. Pink Lady’s Slipper is one of these, luring bees inside the flower pouch with a sweet scent, but offering no nectar. Hairs inside the pouch direct the bee toward the exit where they inadvertently pick up or deposit pollen masses (pollinia) as they escape.
But for many orchids, our understanding of their insect pollinators is still incomplete. Many species of moths, butterflies, and bees have been opportunistically observed to visit Platanthera dilatata, but we aren’t certain which are actually pollinators. With its white flowers, nectar spurs, and strong scent both day and night, White Bog Orchid fits the general profile for visitation by nocturnal moths, but no one has yet studied this in the Northeast.
The shape and size of the flowers, especially the nectar spur, is highly variable in White Bog Orchid. Since flower characteristics determine which insects are attracted to a plant and which can reach the nectar, insect visitors and pollinators likely vary across populations and regions.
This summer, I will be working with VCE as part of my graduate studies in the Field Naturalist Program at the University of Vermont. I’ll be testing some new methods with time-lapse cameras to document diurnal and nocturnal visitation, with an aim to shed light on how important moth pollination might be for White Bog Orchids. I’ll also be digging into VCE’s Pollinator Interactions on Plants dataset to compile which orchid insect visitors have already been observed across the region.
You can help VCE learn more by photographing this and any other orchid you encounter, especially if insects are visiting, and then sharing your observations with us on iNaturalist.
By Kent McFarland
Hear a new rustling up above? It could be mice. Or it could be another small, adorable, furry critter…with wings.
Little Brown and Big Brown Bats, also referred to as “house bats,” are common visitors to residences from about mid-April to October (although the Big Brown Bat may overwinter in attics). These two species are frequently found in buildings, and sometimes in tree hollows or under peeling bark.
During the summer months, females of both species form colonies, sometimes in large numbers, in attics, barns, sheds, or under shingles. This is where they give birth and raise their young. Males also frequent buildings, either alone or in small groups. The females give birth to a single pup in late June or July. At birth each weighs less than an ounce with flesh colored skin covered with fine silky hair. They open their eyes for the first time within 24 hours. The pups in the colony will sometimes huddle close together for warmth while their mothers go out to forage for insects during the night. They won’t be able to fly for 21 to 28 days.
The Little Brown Bat used to be one of the most common tenants in some buildings and bat houses, but due to the devastating effects of a fungal disease known as White-Nose Syndrome, this species has suffered a 95 percent population decline in recent years and are now protected in Vermont. By putting up a bat house, you can provide critical roosting sites for bats (that aren’t in your own attic!) and benefit from their insect-eating abilities. Especially in the summer, many bats and their pups are short-term visitors, so no need to panic. But if you do have evidence of long-term residents, Vermont Fish & Wildlife has information on what to do.
Learn more about bat houses from the Vermont Fish & Wildlife Department. Listen to Outdoor Radio as they visit a colony and learn more.
