Golden-crowned Kinglets & Bridges of Recall

When I was growing up, my grandparents owned twenty acres of woodlands and marshes that were a haven for birds.  My grandfather took long planks, forming Zen-like bridges which zig zagged through the wetlands, creating a trail to the Baker River where we would take long walks, exploring nature. 

The house is located in Plymouth, New Hampshire and used to be an old Stagecoach Inn.  It has hand-hued beams in the ceiling and hand-forged iron latches on the doors. One side of the property borders a babbling brook where my brother and I used to love to play. The brook runs into a bog-like area forming marshes in the lower parts of the neighboring fields.  A rustic stonewall marks the demarcation between our property and a 50-acre farm with its far-reaching fields that extends north to the river.

In the early mornings I take a walk down the old dirt road to sit awhile on the little wooden bridge that stretches over a spot that funnels the wetland marsh waters back into a fast running brook. It’s only about a foot over the water and I can dangle my feet and watch many species of bird from this one spot.

When I was a kid, my brother and I used to pretend this bridge was a floating raft. We imagined we were on some big adventure with snapping turtles, birds and the occasional grasshoppers that would jump aboard.  This was also the place I saw my first Golden-crowned Kinglet. Today, to my delight, I saw not one, but a small group flitting through the lower branches looking for food on this beautiful June morning.

Once you cross the bridge, on one side is a large woodland area. When my children were born the neighbors converted a few areas of the field into a Christmas tree farm, and planted a variety of conifers.  Over the years many of the trees were not cut down and the grove became a forest— the perfect place for birds like the Golden-crowned Kinglet to locate themselves, and now they have flourish.

Golden-crowned Kinglets are tiny, not much bigger than a hummingbird. They are a very social bird, and are not skittish of people. Outside of the breeding season they continue to flock with each other and can be seen with other small songbirds including some Warblers, Chickadees, Downy Woodpeckers and Red-Breasted Nuthatches.

They flick their wings while hopping from branch to branch looking for insects.  Their yummy diet includes aphids, grasshoppers, crickets, lice, bugs, lacewings, beetles, caddis flies, moths, butterflies, flies, bees, wasps, spiders, mites, and some mollusks. In winter the Kinglets also eat small amounts of seeds and may forage in brush piles and under trees.

June begins their nesting season and they are alert, acrobatic and very busy. They raise two large broods of young despite the short season of the northern boreal forest. The female feeds her first brood up to the day after they leave the nest. She then starts laying the second set of eggs while the male takes care of the first brood. The male manages to feed eight or nine nestlings himself, and he occasionally feeds the incubating female too.

Golden-crowned Kinglets may be tiny birds but they are hardier than they look, wintering here where nighttime temperatures can fall easily below
-10° F, sometimes huddling together to keep warm.

They are easy to identify: small, 3 1/4 to 4 1/4 inches long, with a black and white striped face, flashy yellow-orange crown patch outlined by a distinct black eyebrow stripe.  Golden-crowned Kinglets are pale yellow-olive above and lighter below.  A good look can require some patience, as they spend much of their time high up in dense needled foliage. But like all birds they need water and I am lucky to be able to watch them by our little bridge.

Golden-crowned Kinglets are numerous, although populations declined between 1966 and 2014, according to the North American Breeding Bird Survey.  In the U.S., the species declined by over 2.5% per year during this time, resulting in an overall decline of 75%. They are not on the 2014 State of the Birds Watch List.  Logging, forest fires, development and other disturbances have detrimental effects their habitat.  I always considered the views from the main road picture perfect for any postcard or calendar of the area as the two properties have always been a refuge for wildlife and little birds like this one.  Sadly, I fear it will be destroyed for development soon. This little paradise, like so many in this area, will be lost. 

Eastern Phoebe

This sweet bird greets me every morning outside my mom’s kitchen window in New Hampshire. Both the male and the female are building a nest under the back porch by the cellar door. They habitually place their mud, moss and grass nests in protected nooks on bridges, barns and every year they build under my mom’s back porch.

The Eastern Phoebe sings its own name, FEE-be, and can be heard frequently around our yard and the farm here in the spring and summer.  An interesting curiosity I learned about these birds is that unlike most songbirds who must hear other birds to learn their song, an Eastern Phoebe raised in isolation will still sing its perfect FEE-be song, passed down through its genes somehow. 

In 1804, this common flycatcher became famous for being the first bird to be banded in North America.  John James Audubon attached a silver thread to its leg so he could identify him when he returned each year.

 

Flycatchers are fun to watch. They are brownish-gray above and off-white below. They sit upright and perch low in trees, on fence lines or on poles.  They look like they have a big head compared to other birds their size.  The head can also look rather flat with a crown of dark feathers flipping up when they are interested in catching a flying insect of some sort.

 

Phoebes are very active, making short flights to capture insects and very often return to the same perch. Common prey include wasps, beetles, dragonflies, butterflies and moths, flies, midges, and cicadas; they also eat spiders, ticks, and millipedes, as well as occasional small fruits or seeds.

Sadly, the Eastern Phoebe is strongly parasitized by the Brown-headed Cowbird. Cowbird females will roll the Phoebe ‘s eggs and some right out of the nest and in the process, lay her own. The egg is rarely rejected by the Phoebe female. If one of the Phoebe eggs does hatch, the baby bird in a few days will usually starve because of the aggressive large baby Cowbird. 


Nesting Facts for Eastern Phoebe
 

      • Clutch Size
        2–6 eggs

      • Number of Broods
        1-2 broods

      • Egg Length
        0.7–0.8 inch; 1.8–2.1 cm

      • Egg Width
        0.6–0.7 inch; 1.4–1.7 cm

True Colors: How Birds See the World

Guest Author: Cynthia Berger 

IN THE EARLY 1970s, A RESEARCHER testing the ability of pigeons to discriminate colors discovered by accident that the birds can see ultraviolet (UV) light. The finding was deemed curious but not too important. “It was natural for scientists to assume that bird vision is like human vision,” says Geoffrey Hill, an Auburn University ornithologist and the author of Bird Coloration. “After all, birds and humans are both active by day, we use bright colors as cues. … No one really imagined birds might see the world differently.”

But during the following decades, systematic testing of bird vision revealed something unexpected: Many bird species—not just pigeons—can see UV light. Indeed, with the exception of night-flying birds such as owls, the eyes of most birds probably are even more sensitive to ultraviolet light than they are to what we call visible light. Scientists also have learned that many birds have plumage that reflects UV light. Together, these discoveries “made us realize there could be new answers to old questions,” says Drake University biologist Muir Eaton. Birds rely on vision to choose mates, find food and scan for predators, for example. “If you assume birds see exactly what we see, you could have the wrong framework for understanding bird behavior,” Eaton says.

Secret Signals?

Consider how birds choose mates. “After the first studies on birds and UV came out, people started saying, ‘Maybe your study of mate choice isn’t valid because you scored the feather colors with the naked eye,’” says Peter Dunn, a University of Wisconsin–Milwaukee biologist who studies active little warblers called common yellowthroats (below). Adds Hill, who has researched mate choice in house finches, bluebirds and indigo buntings: “When I started working, back in the 1980s, we used to hold up color charts against the birds’ feathers”—the same square paint chips that are an industry standard for graphic designers and interior decorators.

Yellowthroat  During the past three decades, a flurry of studies has tested the intriguing notion that mate choice and other bird behaviors may be shaped by secret visual signals humans cannot see. Though the premise was exotic, what facilitated this explosion of research was prosaic: Technology got better and cheaper. In particular, the increased availability and decreased cost of a lab device called the spectrophotometer—which precisely measures light reflected or absorbed by a surface—let scientists, if not see like a bird, at least quantify what birds are seeing.

Initially, many researchers turned their spectrophotometers on birds that do not use flashy feathers to attract mates. A team of Swedish scientists, for example, looked at the blue tit, a European relative of the chickadee. As with many bird species, male and female blue tits look alike to humans. “Standard literature describes the plumage as closely similar between the sexes,” says Staffan Andersson, a professor of animal ecology at the University of Gothenburg. “The main problem with this conclusion is that it is based on the UV-blind and yellow-biased human eye.” Using a spectrophotometry probe to scan the feathers of wild-caught birds, Andersson and his colleagues discovered that blue tits themselves have no problem telling males from females: Males have a patch of feathers on the crown of the head that strongly reflects UV light; females do not.

Mate Choice

Blue tits are not alone. In 2005, Eaton used a spectrophotometer to scan the plumage of museum study skins of 139 songbird species in which males and females appear alike, from cedar waxwings to barn swallows to mockingbirds to western meadowlarks. Though scientists previously had classified these birds, along with 70 percent of all songbird species, as sexually monochromatic (males and females looking identical), a full 90 percent of the species Eaton scanned actually were sexually dichromatic: different once you took into account the better discrimination of colors (including ultraviolet) by birds and the amount of UV light feathers reflect. “To the birds themselves, males and females look quite different from one another,” Eaton says.

Such findings led some researchers to speculate that the primary role of avian UV vision is to select mates. Indeed, in laboratory tests, Andersson and his colleagues found that female blue tits strongly preferred males with the brightest “invisible” crowns—evidence that the UV-reflecting feathers humans cannot see were serving their function.

Over time, however, scientists have concluded that blue tits are the exception to the rule. Very few bird species use UV light only—with no other visual cues—to attract and choose mates. “In general, ultraviolet reflectance simply reinforces the plumage color patterns we humans already can see,” says Dunn. Among his study subjects, “yellowthroat females do prefer males that are brighter, but not because of the UV reflectance alone. It’s more the brightness of the feathers overall.”

Foiling Nest Parasites

So, how do birds use their power of UV vision? In a surprising number of ways, scientists propose. Many songbirds, for example, are pestered by nest parasites: birds such as cuckoos and brown-headed cowbirds that dump their eggs in a host nest and leave the hard work of childcare to the unwilling adoptive parents. It turns out that some potential hosts are able to recognize and reject eggs that, to human eyes, look like their own. Might birds be responding to UV signals rather than to colors visible to people?

The evidence so far is suggestive but inconclusive. In one 2007 study in the Czech Republic, song thrushes rejected experimental eggs researchers had designed as perfect mimics. It turned out the scientists’ eggs had a UV reflectance different from the thrush eggs. But a Canadian study of 11 species parasitized by cowbirds found no correlation: Some species accepted eggs that were a UV match; others rejected them.

Signals From Hungry Chicks

Scientists also are investigating whether UV signals play a role after eggs hatch. Think of hardworking parent birds, ferrying caterpillars to a nestful of hungry chicks. Which chick gets fed first? In some species, parents cue in on a hatchling’s size or how loudly and energetically it begs. But color also is a factor—the brightness of the gape (edge of the mouth) or the head seems to stimulate a parent to proffer food. Some researchers suggest UV color may enhance this effect.

Newly hatched European rollers, for instance, have a patch of bare skin on the foreheads that reflects UV light. Their parents face a particular challenge as they dole out centipedes and other treats: Because roller clutches hatch over a period of days, first-hatched chicks are larger and need more food than chicks that hatch later. In a 2011 study, Spanish researchers  noted that heavier chicks tend to have the least UV-reflective forehead patches; lighter chicks had more reflective foreheads. To test whether this difference helps parents decide who to feed the most, the scientists smeared a sunblocklike lotion on the foreheads of some chicks, using a control lotion on others. The chicks with the blocker gained less weight than their unblocked nestmates—clearly showing they got less food when they could not advertise their nutritional status with UV signals.

Finding Food

Parent birds may rely on UV signals when they’re off finding food as well. Many insects, includingmoths and butterflies, have body coatings that strongly reflect UV light. Many seeds also are reflective, and berries and fruits develop a highly reflective waxy coating as they ripen. On the other hand, most green leaves do not reflect UV light. So even if a red berry seems quite visible against a green leaf to human eyes, for birds this contrast is enhanced.

American kestral

“I think the biggest thing to come from the discovery that birds see in the ultraviolet is our understanding of how some predatory birds find their prey,” says Hill. Picture, for example, a kestrel (American kestrel, right) perched high on a telephone wire, surveying a field far below. “I always wondered how a bird of prey gets enough to eat,” he says. “After all, you can walk through a grassy field 20 times and never see a mouse.”

But that’s because we do not see what the birds see. It turns out that one key prey for common kestrels, the meadow vole, behaves like a tiny dog, using squirts of urine to mark its trails through tall grass. About 15 years ago, Finnish researchers from the University of Turku discovered that vole urine reflects UV light—which kestrels soaring over open fields can plainly see. “Once you realize raptors can follow the trail right to the animal, it makes a lot more sense,” Hill says.

Indeed it does. While people long have wondered what it would be like to soar like a bird, the more interesting question—particularly for biologists—may be: What would it be like to see like a bird?

Cynthia Berger is a Pennsylvania-based writer & former editor of Living Bird magazine.
Thank you, Cynthia!