April 17-23 Sightings

Stravinsky’s The Rite of Spring – and with all of its beauty and intensity, is the backdrop for this blog. Wharf Cove is teaming with life and competition for it. Have you seen the commotion? As Kathy observed and commented – “The gulls and eiders are vying for food.”

What food? Seaweed flies and their larvae:

Three Seaweed Fly Larvae Photo © Patty Wainright

The seagulls, eiders, swallows, and ducks are intoxicated with these delicacies. Perhaps we view fly larvae as un-palatable, but from their perspective, they are yummy, or if they cannot actually taste them (some bird species do not have taste buds [1]), they satisfy their hunger. And, the birds’ spring hormones are ON. Feeding frenzies, courtship rituals, and territorial disputes were all vibrating at any given moment at Wharf Cove.

Each bird species at Wharf Cove set their boundaries. A pair of Black Ducks dominated over a Mallard pair. If the Mallards ‘paddled over the line’ into Black Duck territory a heavy pursuit ensued, essentially driving the Mallards out of the cove. Defeat was short-lived as they would return to the opposite side of the cove, and they were left unmolested if they stayed there. However, if they got even close to the Black Ducks’ ‘line drawn on the water’, the Mallards were given their marching orders.

Black Ducks

Mallards Photos © Patty Wainright

The other mixed species appeared to tolerate each other better, as long as each kept a healthy distance. The Common Eiders fought within themselves for the plumpest of larva – whirling, jabbing and pushing at one another, and grumbling (grunt calls). The eiders usually obtain their food by diving, with beaks designed for capturing and crushing benthic crabs and mussels. But here they skimmed the surface, making the best of the tools they had.

Common Eider Feeding Frenzy Photo © Patty Wainright

The delicate Ring-billed Gulls probed the surface for the delectable larvae in a fashion that almost appeared ‘polite’.

Ring-billed Gulls, female & immature eiders, Herring Gull

Ring-billed Gull Photos © Patty Wainright

An encounter between a Great Black-backed Gull and a Herring Gull was intense. Was it competition for the food, territory, or courtship issues? (These two species do hybridize.) With locked beaks they fought on the shore – like two wrestlers.

Herring and Great Black-backed Gulls Photos © Patty Wainright

On another occasion, two Herring Gulls engaged in what appeared to be a courtship-march on the water, with heads held regally – however, this march ended in a passionate attack on each other using their beaks, now to cause real harm. Perhaps they were not a pair but were instead two males competing for a female nearby?

Fighting Herring Gulls Photos © Patty Wainright

At the other end of the island, at Woodcutter’s Beach (Woodlanding Cove), a low-key feeding frenzy was underway. The extreme tides allowed for shallow conditions at low tide in the cove. The eiders no longer needed to dive, instead all they had to do was float on the surface, submerge their eyes for bottom searches, and ‘dabble’ for an edible morsel.

'Dabbling' Common Eiders and Great Black-backed Gulls

Woodlanding Cove/Woodcutter's Beach Photos © Patty Wainright

With spring, we also lost some our favorite winter bird residents. The goldeneyes, Buffleheads, most mergansers (a few Red-breasted Mergansers can be seen scattered along the shore), scaups, Surf Scoters, Long-tailed Ducks, and grebes have gone to their breeding grounds further north. Several Black Scoters and White-winged Scoters were observed sporadically along the Backshore and Wharf Cove – perhaps our winter residents have already left and these individuals are passing through from further south? The male Black Scoters flaunt their beautiful orange knobs at the base of their bills. The immature males, too, have some orange hue on their beaks. Most of the Long-tailed Ducks have left except for one pair seen diving for food with the eiders and Black Scoters on the outskirts of Wharf Cove. The female repeatedly dove several seconds after the male, returning to the surface after him, upon finishing their 30 second dives. These Long-tailed Ducks are shown here in their breeding plumage – the male with its long thin tail and pink-banded beak; the female has a mottled grey plumage and beak.

Male and female Black Scoters

Immature Male Black Scoter

Black Scoters, Pair of Long-tailed Ducks, Common Eider

Male Long-tailed Duck

Male and Female Long-tailed Duck Photos © Patty Wainright

The Common Loons were still present offshore, some of which have a partial or full breeding plumage, or an intermediate immature plumage. One loon was observed flying or flapping its large wings – propelling itself over the water without actually flying. Perhaps the loon was exercising its wings with its new flight feathers after being flightless for several weeks? The loons will be leaving shortly (or have already left) for their breeding grounds on lakes. Michelle agrees that “the loon was practicing taking off for flight but that it may have been a first year immature loon that stays on the ocean one more year before breeding and nesting. The immature loon was perhaps trying out its wings now that it has a full plumage. The immature loons have the coloration of the adults, just not as bright.” (Please see the Common Loon Species Account for more information.)

Common Loon Photo © Patty Wainright

Many of the Common Eiders have left for breeding grounds beyond Casco Bay. The remaining eiders are seen in small groups of less than 20. Most individuals within these small groups have formed pairs or are in the process of doing so, and may nest along the island shores in Casco Bay. The male’s plumage is a crisp black and white, with a pink chest, and emerald green spray of color on the sides of their heads. White scapular feathers on their backs form distinct pyramid-shaped tufts – pointing to the sky. The mature female displays little brown tufts to highlight her rich chestnut/sienna brown plumage – along with the two white wing bars (Please see photo from the March blog.).

Male and Female Common Eiders Photos © Patty Wainright

Common Eiders are usually non-aggressive toward other bird species – they prefer to move away from danger. When they panic they may ‘skirt-away’ using their feet to paddle and their wings to move over the water’s surface. Or an eider may ‘jab’ meekly at a thieving gull. However, last week two pairs of eiders were feeding at the Backshore near the Bicycle House. A Great Black-back Gull joined them – hoping for an opportunity to grab the eiders’ benthic bounty. One male eider viciously and relentlessly attacked the gull - until the gull flew off. So eiders are not just timid puffy sea ducks.

A Great Black-back Gull may have gotten the upper hand in an encounter with a different species later in the week. An immature Bald Eagle was flying from Peaks Island toward Cliff Island with this gull in tow. The gull flew above the eagle in preparation for a dive-bomb maneuver. Crows routinely use this technique; they attack potential predators by diving from above at a 90-degree angle. The gull’s 45-degree angle attack was less impressive and it did not appear to affect the eagle’s flight course. The gull gave up or maybe it was just satisfied that the eagle was leaving.

Judy also observed a similar attack on a Bald Eagle: “I was standing on the rocks (Backshore) and three gulls in hot pursuit of a Bald Eagle flew right past me. It was intense! The chase was quite low in the sky - maybe 10-15 feet above my head.”

The Double-crested Cormorants are returning from their southerly winter retreats – many of which will breed on Ram Island. Flocks of cormorants can be observed off the Backshore flying in a V-formation or in straight linear lines – similar to Canada Geese. If you see one of these cormorants in close view, they have tufts or crests located on top of their heads – thereby giving them their name – Double-crested Cormorants. These crests are striking next to the orange-hued beaks, lores, and facial skin, and a full-black body plumage – with splashes of iridescence on their wings.

Double-crested Cormorant Photo © Patty Wainright

The Black Guillemots are in breeding plumage – a striking full-black body plumage with an obvious white wing patch (upper wing coverts); their winter plumage is grey and white. Although not seen while on the water these guillemots have very red legs and feet. Their beaks are black and the interior of their mouth is a bright red. A breeding colony of Black Guillemots is found on Outer Green Island (owned by Maine Department of Inland Fisheries) where National Audubon Society (with logistic support from the U.S. Fish and Wildlife Service [USFWS] Gulf of Maine Program) and students monitor their nesting activities. To protect these ground nesting birds, visitors are not permitted on shore during breeding season (2).

Smaller birds were also observed or heard on the Backshore. Tree Swallows with their beautiful bluish-green iridescent backs were investigating the nest boxes in the marshes of the South Shore and Battery Steele. Bank Swallows with their forked tail and white bellies were also seen. Song Sparrows and Phoebes were singing their tunes of spring. Judy observed (or clearly heard) the Northern Flickers, pecking on her metal roof – evidently taking advantage of the loud sound when beak and metal collide - to impress a potential mate. Judy also spotted a Kestrel in February – outside her window.

Tree Swallows at Battery Steele Marsh Photos © Patty Wainright

I encountered a brown cat at the corner of the South Shore and Backshore – looking at me with the wild-eyes of a feral cat or a guilty cat – in the vicinity of it was a duck’s detached wing (with greenish-blue secondary feathers). Circumstantial evidence?

References

1. Montgomery, Sy. 2010. Birdology.

2. Audubon Project Puffin – Nesting Guillemots at Outer Green Island: http://projectpuffin.audubon.org/outer-green-island

Additional Information

Thank you for your interest in our Peaks Island birds, and if you have observed new birds arriving on Peaks Island either in the woods or other areas please contact Michelle. We can list them as footnotes in future blogs: brownmichh@aol.com

Written by: Patty Wainright

Reviewers: Sam Wainright and Michelle Brown

Thank you for Kathy, Judy and Michelle for your observations.