Part 1: Selected August Bird Activities on Peaks Island

New Peaks Island Bird Watcher Photo © Michael LaCombe

We see new young birders and new young birds on Peaks Island.

Late-summer bird activities are not as obvious to us as they are in the spring when couples gear up to raise a brood - they sing their songs, they build nests. Toddlers are now grown, learning survival skills for when they no longer enjoy parental care. Each bird species has a different weaning strategy. Some species stay together as a family unit (e.g. some corvids) and even migrate together (e.g. sea ducks) but most family members go separate ways. Some migrate, disperse (e.g. Great Horned Owl), and some stay close to home. Whatever their strategy is, they are busy.

Many of Peaks Island’s summer residents have left (e.g. terns, some gulls, flycatchers, swallows, warblers, vireos); others are currently leaving or preparing to do so (e.g. Double-crested Cormorants, herons, egrets, catbirds, blackbirds). Many new birds are merely stopping for a rest and food. Some of our enduring birds will stay with us during the winter (e.g. guillemots, some gulls, eiders, corvids, cardinals, woodpeckers, chickadees). Our strictly winter residents are on their way to PI from their breeding grounds (e.g. sea ducks, grebes, loons, Great Cormorants).

Peaks Island Common Raven

Our year-round corvid residents (ravens, crows, and jays) use different weaning strategies. Common Ravens are the ‘Heavy Weight Thinkers’ of the bird world: Training raven toddlers is complex and the adults are stealth about it. Although their young are boisterous and can be loud, the parents warn them - with a variety of raven-calls - of approaching danger, and then there is silence.

Peaks Island Juvenile Common Ravens

After nearly three months - learning an array of communication skills, and other formidable training, the juvenile ravens will soon be ‘directed’ off the island by their parents. A ‘tough-love’ way of weaning. Once these juvenile ravens are on their own, they somehow find others of their kind – in gangs. But, do the siblings stay together in one gang or disperse separately – finding other gangs? Either way, now welcomed into a gang, the juvenile ravens continue to learn survival skills from each other. They each bring a variety of new skills from different parents – not so different from us.

Peaks Island Juvenile Common Raven

In a few years they mature. Romance is in the air, and they find a partner – one who has shown satisfactory skills in finding food, and of course, sports a velvety blue-purple-black plumage – suggesting good health and no parasites. (1) Where do these new couples nest? This year a raven pair with 4 young are seen twice (July 4 and August 11) on Cow Island. Are they the progeny of our Peaks Island raven pair, or our ravens taking their young for off island excursions?

PI's South Shore Juvenile and Adult Common Crow

American Crows (and Blue Jays) use an entirely different strategy for averting danger, educating their young, and weaning them successfully. Crow parents rely on family members from previous broods to help train and defend the youngsters. Most of the juvenile crows stay within this tightly woven family until they are full adults; other more inquisitive ones may wander to other family units. They work together, carrying on a variety of activities. For example, the crows will ‘triangulate’, each occupying distantly spaced high perches in search of predators, or to just share important crow information. Each call has a different function. They scream and they holler. They dive-bomb any potential aerial predators approaching their territory - taking advantage of being ‘on top of things’ – putting the predator on the defense. However, if the family is caught off guard by, let’s say a Cooper’s Hawk, their strategy changes – the crows are on the defense. The hawk singles out one unsuspecting crow. The crow call now becomes – a distinct and disturbing scream of terror. The crows appear pensive, and silent as they watch their family member struggle for survival. Such an encounter occurred on a mid-August evening as a Cooper’s Hawk chases a crow from Winding Way down 3rd Street. The hawk and perhaps two of them, return the following morning, again on the offense and putting the crows on defense. Individual crows are targeted – an impressive aerial display – putting the entire family into chaos. Finally two of the crows escape to a perch on the highest pines, attempting to take on their typical offense style. Pursuits of crows chasing hawks and hawks chasing crows follow, until they disappear beyond view. Bewildered, the young crows are left to ponder their situation. Who is left of their family?

Juvenile Cooper's Hawk Photo © Robert H. Sauerteig, Jr.

A Cooper’s Hawk, perhaps confused (a juvenile?), settles on Michael’s porch – a “stunning experience” for him, so much so that he is “breathless” and unable to grab his i-Phone for a photograph. The Cooper’s Hawks begin migration in September, suggesting that this hawk is a local, preparing to leave – sooner than later, as far as the South Shore Crow Gang is concerned. This hawk species migration distances are short – some may go only as far lower New England.

Our island bird expert, Lisa, observes another mighty but small hawk, a falcon. An American Kestrel (a falcon) pair raises young in a Lion’s Club oak tree. A gentleman at the ‘Buoy House’ who has a good sight on the kestrel tree, observes the American Crows mob this small kestrel. The crows use a different approach from their typical ‘raven dive-bomb from-above strategy’. Here they attack from below the perched kestrel – “a spectacular sight” that is repeated continuously until this little falcon puts an end to this harassment:

It squats, it expands its feathers, it opens it beak, and looks the crow in the eyes. With drooping shoulders the crow leaves. What message does this crow leave with its young? Kestrels, despite their diminutive stature tease and dive at larger hawks and eagles (2), so standing up to a crow is of little consequence to this little bird.

The American Kestrel is the smallest (3-4 ounces) and the earliest migrating hawk – perhaps as early as the first of August. We (ML, PW) see three kestrels on July 31. One is perched on a large dead branch.

A second bird flies in toward the tree, calling. As the third family member arrives, they all depart the tree and fly together, sometimes in unison – soaring, banking. A ritual flight before migration? They will migrate to mid-southern NA and as far as Panama (Flaco sparverius sparverius subspecies). The kestrel family frequently hunts together. They may depart on their migration routes together (3), however, the males spend their winter farther north than the females, and the juveniles disperse further from nesting grounds than both adults (4).

Juvenile Ospreys on Cow Island

Osprey families are sighted on House Island buoy, at Diamond Island isthmus, (ML) and on Cow Island during the month of August, as late as the 31st. The Osprey, is a one-of-a-kind raptor – strictly a fishing specialist. The Osprey’s reversible outer toe and spiny foot pads are two tricks the Osprey uses to catch and hold slimy fish. Osprey legs are long – to extend their reach for fish below the water’s surface. Did you know that its small intestine is longer than other raptors – to better digest the bony fishes? (4)

The Ospreys in Casco Bay are at the end of their breeding season – teaching their fledged young flight and foraging skills, while they continue to feed them. This relationship ends soon as most Ospreys leave this area early in September. Each family member travels alone. They will fly past the resident Ospreys in southern NA – moving along over open bodies of water to the West Indies and SA. Strong wing beats that alternate with short glides propel them over large bodies of water. After three months in the tropics, most individuals (breeders) return to their natal sites and if nests are available, they will stay nearby. Ospreys are not territorial about an area – they tolerate others nearby. But, they are very territorial of their nests. However, if a Bald Eagle nests nearby, the Osprey may leave entirely. (4) So far the Bald Eagles and Osprey here, in Casco Bay, are co-existing?

Lesser Yellowlegs

Shorebirds, on the other hand, have developed a far different strategy in parental duties – the weaning process. Most adult shorebirds migrate ahead of their young. Many species depart their breeding grounds, leaving the young behind at their nest sites. Why? The parents also leave behind more insects and other invertebrates for their young to gorge before their first big and arduous migration (3) – ranging from hundreds to thousands of miles of uncharted lands to navigate with uncertain food sources along the way. So they must ‘fill-up’ – feeding on their departed parents’ share of food.

And currently, shorebirds are in the midst of their migration, and we are treated to spectacular sightings of these birds – a shorebird tour led by Derek Loritz (3) - to the marshes, beaches, and mudflats of southern Maine.

Please go to Part 2 of this month’s blog: Shorebird Migration: Biddeford Pool and Scarborough Marsh

References:

1. Heinrich, B. 1999. Mind of the Raven: Investigations and Adventures with Wolf-Birds. HarperCollins Publishers, Inc. New York, NY.

2. Brett, J.J. (1973) Feathers in the Wind. Hawk Mountain Sanctuary Association. Kutztown Publishing Co. Inc. PA.

3. Lovitch, D. Freeport Wildbird Supply. www.freeportwildbirdsupply.com

4. del Hoya, J., A. Elliot and J. Sargatal. Eds. 1994. Handbook of the Birds of the World. Vol. 2. New World Vultures to Guineafowl. Lynx Edicions. Barcelona.

Other Information:

Contributors: Derek Lovitch, Michael LaCombe, Lisa Lynch, Gentleman at Buoy House.

Reviewed by: Michael LaCombe, Michelle Brown, Marty.

By: Patty Wainright

Photographs: Photo © Patty Wainright

Additional Information:

If you have any additional bird sightings you would like to share or questions regarding Peak's bird life, you can send them to: brownmichh@aol.com.