Local birding report

The last few nights of April saw a huge influx of northbound traffic in the night skies across the U.S. Cornell Labs BirdCast predicted upwards of 300 million birds in flight per night.

Flying at night is a risky business. One way to increase chances of success is for birds to travel in small flocks, constructively working as a team. Many songbirds including warblers, sparrows and thrushes use short, high-pitched nocturnal flight calls to communicate while on the wing. These distinct calls most likely evolved to facilitate collective decision-making, helping flocks of birds stay together and navigate in darkness.

A few observations over the last several weeks from the yard include - two continuing Pine Siskins that have hung around the feeders since late February. On most days, high up in the Oak Trees I can hear the pair’s wheezy trills and “watch winding” call intermingled with the Goldfinches’ twitters and warblers. Unlike the Goldfinches who, at my presence quickly scatter, these two nomadic finches will sit on perches and allow me to pass by them at close range. One late afternoon the two siskins were alone on the finch tube when four female Purple Finches appeared.

On April 25 three Pine Warblers showed up on the suet. Interestingly, two of the three warblers were almost completely devoid of yellow and identified by the presence of their two wing bars.

Additionally, on April 26 I spotted my first Palm Warbler and Blue-headed Vireo of the season. Blue-headed Vireos are a joy to come across with their moss-green body and clean white “spectacles” set off against a blueish-gray head. With a bit of patience, I was able to hear the vireo whispering its cheerful carol song. Blue-headed vireos move in a deliberate, methodical fashion, which contrasts with the lightening quick pace of wood warblers occupying the same middle elevations of mature and second growth woods.

On April 27 a friend reported large numbers of Laughing Gulls gathered in Peables Cove at the mouth of the Alewife Brook. I also spotted my first Brown Thrasher of the season crossing Two Lights Road and later that afternoon spied five Ruby-crowned Kinglets, two Savannah Sparrow, a Hermit Thrush and a single Eastern Towhee along the splendid little Greenbelt Trail tucked along the western side of the Riverside Cemetery. And as dusk arrived my wife and I watched a Great-horned Owl hunting in a field off Shore Road.

Lastly on the overcast afternoon of April 28 along the Sawyer Road section of the Spurwink River I noted twenty-one Glossy Ibis foraging, seven Greater Yellowlegs wading and two Pectoral Sandpipers probing. The Pectoral Sandpiper is a stout shorebird that is about the size of a robin and has a rather long, noticeably thick bill and long wings. Males are 50% larger than females. Adults are cloaked in brown, gold and black above with a white belly and neat dark-brown rows of “stipples” across the breast. These sandpipers will hang around only briefly before heading for the wet grassy tundras across Northern Canada to breed.

Later in the afternoon of April 28 while watching a Merlin cruising at top speed across the Spurwink Marsh, a white heron-like bird appeared in my binocs as it sailed into the saltmarsh. Upon closer inspection the bird appeared about the same size as a Snowy Egret but had a yellow bill and legs.

Most striking was the heron’s golden orangey feathering on its head and chest. After spending a couple minutes in the marsh preening, the heron flew back to a nearby grassy field to forage. Two other white herons can be found this time of year, the Great Egret, which is much larger and longer and juvenile Little Blue Herons, which are very slender mostly white birds with a pale blue gray bill. What I was seeing was a Western Cattle Egret, and the first time I had seen one in Cape.

In 2023 scientists decided to split the Cattle Egret into two species, Western and Eastern. Western Cattle Egrets can be found from Africa to southern Europe and North America.

Native to Africa, the “cow crane” or “hippopotamus egret” prefers drier upland areas like fields to stock prey versus other species of white herons who prefer to wade. Western Cattle Egrets arrived in the United States in 1941 and according to Peter Vickery’s Birds of Maine, the egrets have been occasional spring visitors to Maine’s coastlines and agricultural fields since 1950s.

The first nesting pair was recorded in Maine on Stratton Island in 1974. Western Cattle Egrets successfully have bred in southern Maine up until the early 1990s. Since then, breeding populations in Maine have dwindled significantly despite an otherwise remarkable range expansion across North America. The primary breeding challenges in Southern Maine for Western Cattle Egrets include, habitat preference of field over stream, nesting sites which is limited to a few coastal islands, and competition from other bird species vying for nesting sights or resources.