Bird Rhythms – February 2019

Kachemak Bay Birder Carol Harding, highlights the February Bird of the Month – Rock Sandpiper.  This hardy bird winters in Homer, and can be found roosting at high tide at the Homer Small Boat Harbor.  Carol also describes two different processes found in birds:  “irruptive” and “leucistic”.  The “irruptive” process, occurs where birds, not readily seen in the Homer area during the winter, appear in great numbers, such as the increase in the number of Red Crossbills this winter and last.  A “leucistic” bird is one that has white feathers, whole or in part.  These birds are not albinos, as they lack the red eye.  Listen to Carol as she explains these fascinating aspects of bird life. 

Glaucous-Winged Gull – March 2019 Bird of the Month

General Information:  The Glaucous-winged Gull (Larus glaucescens) is a common west coast breeder and winter resident found year-round in on the Kenai Peninsula.  No sexual dimorphism here – both male and female look alike.  They are members of the Order: Charadriiformes (which includes Shorebirds), Family: Laridae (Gulls and Terns)

North America Range

Source: https://www.allaboutbirds.org/guide/Glaucous-winged_Gull/maps-range

Bird Biology:

Characteristics:  All ages have pink legs – a good field ID.  From there it becomes more difficult as this gull doesn’t reach adult plumage until its fourth year.  And, to add to the confusion, there are the breeding and non-breeding plumages (although not that much different).  A good field bird book is needed if you want to be familiar with gulls.

Glaucous-winged Gulls are large, ranging in size from 19 -23 inches, and weighing in at around 2.0-2.5 pounds, slightly larger than a Herring Gull, but slightly smaller than a Glaucous Gull.

Adults: Look for a large, stocky gray/silver gull with gray back and gray/silver (not black) wingtips, with white spots near tip.  Eyes are dark compared to light eyes on Herring and Glaucous Gulls.   Their bill is yellow with some red on lower mandible and don’t forget the pink legs.  Breeding birds have an all white head and neck, while non-breeding birds have mottled gray in the head and neck.  They are commonly found in pairs year-round, but will forage alone or in large groups. 

Adult Glaucous-winged Gull
Photo by Michelle Michaud

There are a number of different plumages for birds that have yet to reach sexual maturity.  For a description of the different plumages go to: https://www.allaboutbirds.org/guide/Glaucous-winged_Gull/id

Juvenile Glaucous-winged Gull
Photo by MIchelle Michaud

Preferred Habitat:  Look for the Glaucous-winged Gull near or on coastal water year-round.  It prefers good food sources such as bays, inlets, estuaries, beaches, harbors, mud flats, and spends much of the winter loafing on offshore waters and beaches.

In the breeding season, this gull nests on steep coastal cliffs and rocky offshore islands (e.g., Gull Island). 

Breeding Season:  Begins mid-May to early June, ending in August.   Glaucous-winged Gulls do not begin breeding until their fourth year or later and breeds/nests in colonies, sometimes quite dense.  As a social breeder, it may breed/nest in colonies with other gull species or seabirds (e.g., puffins, murres).

Nesting:  Preference for a nest site is a nest on the ground, rock ledges, and cliffs, but they may nest on suitable buildings or structures.  The pair will ‘nest bond’, generally starting several nests, but completing only one nest. 

The nest is a bulky cup shape consisting of grasses, seaweed, feathers, fish bones, and other debris (including plastic, unfortunately).  The use of plastic by birds is not a good use of “recycling plastic”since the plastic often be ingested or will entangle the nesting bird or chicks. 

Eggs and Incubation: Typically 2-3 eggs are incubated by both parents for 26-29 days.  Hatchlings are semi-precocial (eyes and ears open, but cannot move about) and downy.  The chicks are fed by both parents.  The chick’s coloring is cryptic to help camouflage it from predators, including other Glaucous-winged Gulls. 

Hatch Year Glaucous-winged Gull
Photo by Michelle Michaud

Fledging:  The chicks generally fledge 35-54 days following hatching and will leave the colony about two weeks later to forage on their own. 

Food Preferences:  Their primary food source is marine invertebrates (limpets, chitons, clams, mussels, squid, crab etc.) and fishes.  They will also predate seabird eggs and chicks.  They scavenge carrion and will eat food found in landfills and parking lots.  Unfortunately people feed gulls, which attracts a lot of gulls in a feeding frenzy. The gulls create a riot as they swoop in to grab the morsel.  This human activity is not appropriate and illegal within the City of Homer.  Gulls have a notorious reputation of hanging out, in large numbers and in mixed flocks, at landfills seeking food so many birders check out landfills to see if there are any rare gulls present. 

Feeding Methodology:  These gulls forage at sea, in intertidal areas, along beaches, in parking lots and landfills.  When on land they are ground foragers.  They take prey from the surface of water or may perform a dramatic plunge into water from the air.  They will try to harass and steal food from other birds, such as cormorants. 

Roosting:  They a social roosters with beaches a favorite roosting spot but they can also be found roosting on pilings, guardrails, lamp posts, parking lots, and in fields or dumps

Adult Glaucous-winged Gulls Roosting on the beach at Anchor Point
Photo by Michelle Michaud
Glaucous-winged Gulls and a single Glaucous Gull roosting on the Homer Ferry Dock
Photo by Michelle Michaud

Migration:  Not all Glaucous-winged Gulls migrate as many northern birds are year-round residents, moving with the food resources.  For those that do migrate, spring migration is from late February to early May.  Fall migration is from late August to late November.  They may migrate as far south as northwestern Mexico but are rarely found inland, preferring a coastal environment. 

Vocalizations:  This bird’s call is a “keow” whistle.  If an intruder approaches you will here the ‘ga, ga’ notes.  I think that is one we’ve all heard and is most familiar. 

Threats:  Fishing line and hooks are deadly as Glaucous-winged Gulls are opportunistic scavengers and can ingest a hook or get entangled.  So if you see fishing line and hooks on the ground, pick them up and dispose of them properly.  And if you are out fishing, do not discard these items onto the ground or from your fishing boat.    

Gull with fishing line and lure attached to it.
Photo by Michelle Michaud

Fun Facts:

  • This bird hybridizes with the Herring Gull, Western Gull, and Glaucous Gull.  The young may possess physical characteristics of both parents. 
  • Gulls are often difficult enough to identify, especially before they reach sexual maturity, but added to that is the fact that they often inter-breed and hybridization makes field identification more difficult.  Pete Dunne recommends that if you find a gull with “… a mixed array of traits, consider the very possibility that it’s a hybrid” and either try to tease out what the bird is or move on to another gull. 
  • This is the one of five North American Gulls that does not have black on its wing-tips.

Conservation Status: 

Audubon Alaska has identified the Glaucous-winged Gull species as a common species that is declining or vulnerable, thereby warranting species conservation attention.  It is estimated that 44% of the bird’s population resides in Alaska making it at-risk for climate change and other environmental influences. 

The International Union for Conservation of Nature and Natural Resources (IUCN) has identified the population of the Glaucous-winged Gull as increasing, with no genuine threats to the global population estimated at over 570,000 individuals.

Similar Species in Alaska:  Glaucous Gull, Herring Gull

Sources of Information:

All About Birds.  Cornell Lab of Ornithology.  Downloaded on January 10, 2019 at https://www.allaboutbirds.org/guide/Glaucous-winged_Gull/id

Baicich, Paul J. and Harrison, Colin J.O. 1997.  Nests, Eggs, and Nestlings of North American Birds, 2nd Edition. Princeton Field Guides.

BirdLife International 2018. Larus glaucescens. The IUCN Red List of Threatened Species 2018: e.T22694334A132543276. http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T22694334A132543276.en. Downloaded on 10 January 2019.

Dunne, Pete.  2006.  Pete Dunne’s Essential Field Guide Companion:  Comprehensive Resource for Identifying North American Birds.  Houghton Mifflin Company. 

Lucas DeCicco/McCaulay Library/Cornell University Ornithology Lab (ML174609).

National Audubon Society.  Audubon:  Guide to North America Birds.  Downloaded on January 10, 2019 at: https://www.audubon.org/field-guide/bird/glaucous-winged-gull

Todd, Frank S.  1994. 10,001 Titillating Tidbits of Avian Trivia. Ibis Publishing Company.

Warnock, N. 2017. The Alaska WatchList 2017. Audubon Alaska, Anchorage, AK 99501.  Downloaded on January 10, 2019 at: http://ak.audubon.org/sites/g/files/amh551/f/annotated_watchlist_common_decline_2017.pdf

The gallery was not found!

Rock Sandpiper – February Bird of the Month – 2019

Rock Sandpiper

(Calidris ptilocnemis)

Wintering Rock Sandpiper at Homer Boat Harbor – Photo by Michelle Michaud

General Information:  The Rock Sandpiper is a shorebird that can be found in Cook Inlet, including on the Homer Spit during the winter.  The Rock Sandpiper has a small range – Alaska, Northern Siberia, and west coast of Canada.  This bird is a member of the Scolopacidae family and consists of four subspecies.     

Range:

Source: https://www.allaboutbirds.org/guide/Rock_Sandpiper/maps-range

Bird Biology:

Characteristics:  During the winter, this plump, medium-size shorebird is sooty gray in color, with heavily spotted white underparts.   The summer plumage resembles the look of  a breeding Dunlin, only messier (the black on the chest is smudged, rather than the clean margins of the black found on the Dunlin breast and belly).  It has a medium-length black bill with orange at the base, and drooping slightly at the end.  The bill is shorter than a Dunlin, longer than a Surfbird.  The short legs are a greenish-yellow color, and it has a  white wing-stripe( wing bar).  Look for a dark tail in flight.

The sandpiper weighs in at 2.0-4.6 ounces, and is 7.1-9.4 inches in length.   Both sexes have the same plumage – no sexual dimorphism here.   Overall size wise – think American Robin. 

A non-breeding Dunlin is located in the center of the photograph, surrounded by Rock Sandpipers. Notice the difference in coloring and bill length. Photo by Michelle Michaud

Preferred Habitat:  During the breeding season, the Rock Sandpiper breeds in low-elevation tundra areas, but may also nest at higher elevations in the mountains of western Alaska.  Wintering habitat includes rocky coastlines, breakwaters, and mudflats. 

Roosting Rock Sandpipers at the Homer Alaska Boat Harbor – Photos by Michelle Michaud

How many Rock Sandpipers can you count in this photo?

Breeding Season:  The breeding season begins in early June.  The Rock Sandpiper is a common breeder in Alaska. 

Nest:  This ground nester scrapes the ground, then lines the depression with grasses, lichens, and leaves.  The male begins the scrape, with the female occasionally helping  to construct the lining.

Eggs and Incubation:   Fur eggs are usually laid at daily intervals.  Both parents incubate the eggs over approximately 20 days, with the chicks hatching at different intervals.  The chicks are born precocial (leaving the nest shortly after bird and feeding on their own).  The male tends the young until they fledge. 

Fledging:  The chicks fledge (able to fly) approximately 3 weeks following hatching. 

Food Preferences: On the breeding grounds, protein is needed and the diet consists primarily of insects, but also crustaceans, mollusks, and marine worms.  Supplements include  berries, seeds, moss, and algae.  In the winter, they utilize tidal areas and eat mostly crustaceans, insects, and small mollusks. 

Feeding Methodology:  In the winter the Rock Sandpiper forages in the intertidal zone (rocky coasts, mudflats, gravel beaches, sand flats, ) where it finds its food visually. 

Roosting:  This sandpiper roosts above the high tide line on piers, beaches, and rocky banks.  It can be found roosting along the inner eastern bank of the Homer Boat Harbor during high tide in the winter months.

Migration:  Spring migration is from late March to early June.  Fall migration is from late June to mid-November.  Peak fall migration occurs later than other shorebirds.  The subspecies of Rock Sandpipers nesting on the Pribilof Islands and in the Aleutians are short-distance migrants or permanent residents.  The primary Rock Sandpiper wintering in Homer is a summer resident of the Pribilofs and Aleutians.

Vocalizations:  This bird is generally silent, but listen for low whistled notes sometimes vocalized in the winter. 

Threats:  Change of habitat due to climate change and exposure to predation.  Also, while the Rock Sandpiper can be enjoyed in large numbers roosting at the Homer boat harbor and feeding at the tidal flats, winter is an energy stressor so disturbance from dogs and people is a problem.

Fun Facts:

  • There are four subspecies of Rock Sandpipers with each subspecies having differing breeding plumage, but mostly look alike during the winter.
  • Several subspecies winter in Cook Inlet and Kachemak Bay. Several thousand wintering Rock Sandpipers can be found roosting, bathing, and preening on the northern half of the eastern bank of the Homer Boat Harbor or seen flying around the Homer Spit and landing on the tidal flats to feed.  By late April the majority of the Rock Sandpiper’s have departed Homer for their breeding grounds.
  • Check your photos and look carefully since small numbers of Dunlin often winter with Rock Sandpipers in Kachemak Bay, and can be confused for Rock Sandpipers (see photo above to see the difference).
  • The Rock Sandpiper is closely related to the Purple Sandpiper (which resides seen on the east coast of the United States and Canada)
  • Like a plover, the Rock Sandpiper may exhibit the broken wing display if a predator threatens the nest.
  • A hardy bird – its wintering area often means ice on feet and legs – no problem for the Rock Sandpiper with its specialized metabolism.

Conservation Status:  The estimated global population is 160,000-170,000 individuals. 

The subspecies C. ptilocnemis ptilocnemis, found in the Pribilof, St. Matthews, and Hall Islands of Alaska are listed on the Alaska Audubon Watchlist 2017 Yellow List – Vulnerable Species.  Species on this list are declining or vulnerable thereby warranting special conservation attention. The subspecies population status is estimated at around 20,000 birds.  This subspecies primarily winters in Cook Inlet.

The International Union of Concerned Scientists have listed (Red List) the Rock Sandpiper as a species of least concern, but with a declining population. 

Similar Species in Alaska:  Surfbird, Dunlin, and Wandering Tattler

Marked Birds:  If you see or find a Rock Sandpiper with a metal band, colored plastic leg bands, and engraved colored leg flats, please report your details to:

Dan Ruthrauff
USGS Alaska Science Center
4210 University Dr., Anchorage, Alaska, 99508
(907) 786-7162, druthrauff@usgs.gov

These birds were marked at several sites in western Alaska and are part of a distribution study.

Sources of Information:

All About Birds.  2017.  Cornell Lab of Ornithology.   Downloaded on 15 August 2018 at: https://www.allaboutbirds.org/guide/Rock_Sandpiper/id

Audubon:  Guide to North America Birds.  Downloaded on 15 August 2018 at: https://www.audubon.org/field-guide/bird/rock-sandpiper

Baicich, Paul J. and Harrison, Colin J.O. 1997.  Nests, Eggs, and Nestlings of North American Birds, 2nd Edition. Princeton Field Guides.

BirdLife International. 2016. Calidris ptilocnemis. The IUCN Red List of Threatened Species 2016: e.T22693424A95218793. http://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22693424A95218793.en. Downloaded on 15 August 2018.

Dunne, Pete.  2006.  Pete Dunne’s Essential Field Guide Companion:  Comprehensive Resource for Identifying North American Birds.  Houghton Mifflin Company.  

Gill, R. E., P. S. Tomkovich, and B. J. McCaffery (2002). Rock Sandpiper (Calidris ptilocnemis), version 2.0. In The Birds of North America (A. F. Poole and F. B. Gill, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.686.  Downloaded on 15 August 2018.

Lucas DeCicco//Macaulay Library at the Cornell Lab (ML Audio176399).

Ruthrauff, Dan, U.S. Geological Service, Alaska Science Center.  Wintering Ecology of the Rock Sandpiper.  Downloaded on 15 August 2018 at: https://alaska.usgs.gov/science/biology/shorebirds/rosa_ecology.php

Todd, Frank S.  1994. 10,001 Titillating Tidbits of Avian Trivia. Ibis Publishing Company.

Warnock, N. 2017. The Alaska WatchList 2017. Audubon Alaska, Anchorage, AK 99501.

It’s A Great Day to Bird

Long-tailed Duck – January Bird of the Month – 2019

Long-tailed Duck

(Clangula hyemalis)

Male Long-tailed Duck in breeding plumage. Photo by Robin Edwards

General Information:  Formerly known as Old Squaw, this duck is a circumpolar breeder and a common winter resident in Kachemak Bay off the Homer Spit.  The “old squaw” name was in reference to the bird’s talkative behavior, although it is the male Long-tailed Duck that “talks” the most. 

The Long-tailed Duck  is a member of the Anatidae family, and the only living member of the genus Clangula

Range:  You will have to travel north to find these birds – summer or winter.    In North America they winter in the northern portions of the eastern U.S., Alaska, and Canada, and breed in the Alaska, northern Canada, and the Soviet Union. 

Source: https://www.allaboutbirds.org/guide/Long-tailed_Duck/maps-range

Worldwide Range

Source: http://maps.iucnredlist.org/map.html?id=22680427

Bird Biology:

Characteristics/Description:   The summer breeding plumage is distinctively different from the winter plumage.  In summer, males have a black head, chest, and wings with a gray face patch that surrounds the eyes.  The male’s upper back feathers are long and buffy with black centers.  The central tail feather very long (hence their name).   The male’s winter plumage, displays a white head and neck, but the gray face patch remains.  The winter plumage also includes large black spots extending from the side of the check down through the side of the neck.  There is a black band across the breast and lower neck.  Their lower back is black.  The upper back feathers are long and gray.  The central tail feather is black.  Eyes are a dull yellow-brown. 

Male winter plumage. Photo by Michelle Michaud

Male Summer plumage. Photo by Michelle Michaud

Females in the summer have mostly a dark head and heck, with a white patch around the eyes, extending in a thin line towards the ears.  Back and breast are various shades of gray or brown.  Eyes are brown.  During the winter, their head and neck are white with a round dark brown cheek patch.  They have a white belly.  Their crown, breast, and back are brownish-gray.

Female Winter plumage. Photo by Robin Edwards

Female Summer plumage. Photo by Michelle Michaud

Both sexes have uniformly dark under-wings, and small bodies with large heads.  They sit low in the water and are often hidden by the ocean waves. 

Preferred Habitat:  During the breeding season, lakes and ponds are preferred.  During the winter, they prefer the open ocean and can also be found on large freshwater lakes.  A good spot to find them in Kachemak Bay is off the end of the Homer Spit.

Breeding Season:  Breeds in the northern Arctic boreal forest and tundra, utilizing open permafrost pools and lake islands.  The breeding season begins in late May in the south, to June in the north.  They have a single brood. 

Nest:  The nest is a shallow scrape on the ground (often islands or peninsulas), lined with nearby plant material (e.g., willow and/or birch leaves), down, and feathers.  The nests are placed close to the water.  These birds are sociable nesters, nesting near other Long-tailed Ducks. 

Eggs and Incubation:  Usually 5-9 eggs constitute a clutch.  The female incubates the eggs for 23-25 days.  The chicks are born precocial (eyes open) and downy.  The young are lead to sea shortly after hatching.  They are able to swim, dive, and feed themselves immediately. 

Fledging: The hatchlings become independent approximately 5 weeks after hatching. 

Food Preferences:  Long-tailed ducks eat aquatic invertebrates – crustaceans (e.g., amphipods and cladocerans), mollusks, fish, and other marine invertebrates.  During the breeding season, they will also eat freshwater insects and insect larvae, plant material (algae, grasses, seeds, and fruits of tundra plants). 

Feeding Methodology:  Long-tailed ducks are “diving” ducks. 

Migration:  The Long-tailed Duck migrates from its breeding ground in the far north to its wintering grounds in the not so far north.  Spring migration to the breeding grounds begins late February through May, and fall migration to the wintering grounds begins in October continuing through December.   The migration is often in groups, and the birds fly low over the water. 

Vocalizations:  These birds are active vocalizers all year long.  Their call is a three-part yodel. 

Threats:  These birds are “sea” birds and are susceptible to by-catch in gill nets, and oil pollution.

Fun Facts:

  • This bird can dive 200 feet, although most food is obtained within the first 30 feet of the surface. One of the deepest diving ducks in the world. 
  • A diving duck, it spends more time underwater than it does on top of the water.
  • Adults molt three times per year, rather than the typical two times per year of other ducks.
  • And that beautiful plumage we see during the winter? That is actually their breeding plumage (attracting a mate), although the birds actual breed during the spring where their plumage is non-breeding plumage.  Confusing right?

Conservation Status:  The world population is estimated at between 3.2 million and 3.75 million birds. 

The International Union of Concerned Scientists list the Long-tailed Duck as vulnerable due to the severe wintering population decline in the Baltic Sea between the early 1990s and late 2000.

The Alaska Audubon Society has identified the Long-tailed Duck as a species in possible decline on the Yukon-Kuskokwim Delta, although stable on the Alaska Coastal Plain (Audubon Alaska Watchlist 2017:  Common Species Suspected to be Declining). 

Similar Species:  Harlequin Duck, Northern Pintail, Steller’s Eider.

Sources of Information:

All About Birds.  2017.  Cornell Lab of Ornithology.  Downloaded on 29 July 2018.  https://www.allaboutbirds.org/guide/Long-tailed_Duck/id

Audubon: Guide to North American Birds.  Downloaded on 30 July 2018 at https://www.audubon.org/field-guide/bird/long-tailed-duck

Baicich, Paul J. and Colin J.O. Harrison.  19997.  Nests, Eggs, and Nestlings of North American Birds, 2nd Edition.  Princeton Field Guides. 

BirdLife International. 2018. Clangula hyemalis (amended version of 2017 assessment). The IUCN Red List of Threatened Species 2018: e.T22680427A122303234. Downloaded on 29 July 2018.

Dunn, Jon L. and Jonathan Alderer, Editors.  National Geographic: Field Guide to Birds of North America.  5th Edition, 2nd Printing.  2008.

Dunne, Pete.  2006.  Pete Dunne’s Essential Field Guide Companion:  Comprehensive Resource for Identifying North American Birds.  Houghton Mifflin Company. 

Henri Ouellet//Macaulay Library at the Cornell Lab (ML Audio 74469)

Warnock, N. 2017. The Alaska WatchList 2017. Audubon Alaska, Anchorage, AK 99501.

American Dipper – December Bird of the Month – 2018

American Dipper

(Cinclus mexicanus)

Photo by Michelle Michaud

General Information:  As the name implies, the American dipper (Cinclus mexicanus), also formerly known as the “Water Ouzel”, is characterized by its dipping movements.  The American dipper is a stocky dark grey bird with a head sometimes tinged brown and distinctive white feathers on the eyelids that cause the eyes to flash white as the bird blinks.  It has long legs, and bobs its whole body up and down while perched on a rock in or near a stream.

The American Dipper’s habit of ‘dipping’ or bobbing up and down while perched on a rock or ledge is not well understood though some believe the action of dipping may help them spot prey beneath the surface of the water or help conceal their image from predators.  Dipping may also be a form of visual communication between birds in the noisy environment they favor – clear, clean, fast-moving streams.

The American dipper is of the Order, PASSERIFORMES; Family, Dipper (Cinclidae).

Range:  The American Dipper is ‘Alaska Hardy’ — a permanent resident of the Kenai Peninsula, but also able to tolerate winters even in the Brooks Range and Seward Peninsula.  Now that’s cold. 

The American Dipper is North America’s only aquatic songbird, and one of five species of dipper in the world (Europe, Northern Africa, Asia, South America, and North America).

Range Map Source:  https://www.allaboutbirds.org/guide/American_Dipper/maps-range

Bird Biology:

Characteristics:  It is hard to mistake the American Dipper with its dependency on streams and its iconic bobbing nature.  Look for a bird 5.5 to 7.9 in (14 to 20 cm) in length, and weighing in at 1.5 to 2.4 oz. (43 to 67 g).  Males and females look alike, although the average body mass of males is slightly greater than females.  Unlike most other songbirds, but similar to ducks, the American Dipper molts its wing and tail feathers all at once in the late summer. The bird is flightless during this time.

Find a fast-moving stream, look for a stream boulder, and the probability of seeing a dipper increase as they will spend up to 10 minutes preening (preen oil glands), creating their form of wet suit – necessary for waterproofing and insulation.

The American Dipper takes a ‘polar dip’ in the cold water with relish. It is well-adapted to its cold, underwater habitat. The American Dipper has a thick coating of down and feathers as insulation, large preen glands secreting oil to waterproof their feathers, a moveable flap over the nostrils that seals when the bird is underwater, blood cells with a large capacity for carrying oxygen, and an efficient internal system of thermoregulation.

Preferred Habitat:  American Dippers are stream-dependent, foraging in clear fast-moving streams with rocky bottoms.  They prefer unpolluted waters, and can be found in mountain, coastal, or even desert streams.

Breeding:  Dippers are fiercely territorial, vigorously defending their linear stream-dependent nesting territory from other pairs. They are mainly monogamous and in most cases return to the same nest year after year. The American Dipper breeds along swift, rocky streams, seeming to favor clear, cold water, often in narrow canyons. Seem repetitive…Guess you have the picture now about stream preference.

The courtship display may have either the male or female strutting and singing in front of the other bird, with wings drooping and bill pointed up.  The pair may then conduct a ‘flight chase’ with complex aerial maneuvers, all the while singing.  Though some pairs stay together in winter, the dipper is generally a solitary bird; after the chicks’ fledge, parents often divide their brood and their territory and part ways.

Nesting:  The nest, probably built by the female, is a volleyball-sized shell of moss, with an inner saucer of dry grass on which 4-5 white eggs are laid. In Alaska, nest building usually begins in April or May, though cold weather and high altitudes may result in delayed nesting.

American Dipper nests (Photo by Michelle Michaud)

Nest sites include a slight ledge on a mossy rock wall just above stream, among roots on a dirt bank, or behind a waterfall.  The nest is often placed where it remains continuously wet from flying spray.  Many dippers commonly select nest sites under bridges – an adaptable bird.  Good nest sites seem to be the main limiting factor for the presence of a population of dippers.  So if you see a bridge near a fast moving stream and you can look under the bridge, check for a dipper nest.

Bridge which housed several dipper nests (Photo by Michelle Michaud)

American Dipper gathering nesting material – Photos by Michelle Michaud

The clutch is incubated for 2 to 2.5 weeks. Females do all the incubation, but males bring food to the incubating female. The female will brood the chicks for a week or more while the chicks grow feathers to help regulate their body temperature. Both parents feed the chicks, bringing insects and small fish – feeding the hungry brood as many as 20 times an hour.  One would think the parents would be worn out after all that activity, but second broods have been recorded.

Fledging:  When born, the chicks are helpless with sparse down, but are ready to leave the nest in about 24-25 days.  The young are fed by both parents for another two weeks after fledging, as they gradually learn how to find and catch their own prey.  Chicks are able to swim and dive after fledging.

Hatch Year Bird (Photo by Michelle Michaud)

Food Preferences:  The American Dipper feeds on aquatic insects and their larvae (yay! mosquitoes) and may also eat fish eggs and very small fish (less than 3″ long).

Feeding Methodology:   The American Dipper can wade, swim, and dive from either the water or the air and are capable of moving underwater rocks on the stream bed to get food.

Photos by Michelle Michaud

The American Dipper uses its short, stubby wings to ‘fly’ underwater with powerful strokes of their partially folded wings when chasing prey.  They can take prey from the water’s surface while swimming or from mid-air while in flight, but most food is taken underwater.

With its long legs and strong toes, the American Dipper is an underwater marvel; easily able to negotiate along the bottom of fast-moving, rocky streams in current capable of knocking over you or I.

Roosting:  A variety of sites on the ground adjacent to streams are used for nocturnal roosts.

Migration:  The American Dipper is not a long-distant migrant so it is a ‘Homer Bird’ — a  permanent resident of the Kenai Peninsula; but it may move to other locations if necessary to find food or unfrozen water.

Vocalizations:  The song consists of high whistles or trills peee peee pijur pijur repeated a few times.  The song has also been described as a loud, bubbling song.  Whatever you interpret, you will hear the dipper as the song carries over the noise of stream rapids.   Both sexes of this bird sing year round, but are often quiet after nesting.

Call:  The call is a harsh, zeet-zeet-zeet.

Fun Facts:

  • Eat and be eaten… The American Dipper eats fish eggs, but its habit of diving underwater in search of food can infrequently make it the prey of large salmonids.
  • To see an American Dipper stay close to a stream as the dipper will be seen bobbing up and down on a rock in mid-stream, or flying low over the water, following the winding course of a stream rather than taking overland shortcuts.
  • The American Dipper is equipped with an extra eyelid called a nictitating membrane allowing it to see underwater.

Conservation Status:  American Dipper presence/absence can be an indicator of stream quality, as aquatic prey becomes scarce in polluted streams.  No food, no dippers.  The dipper has vanished from some locations due to pollution or increased silt load in streams. Also, sedimentation, acidification, and toxic waste from industry of various types can cause dipper reproductive failure and abandonment of a stream.

The American Dipper’s population status is thought to be a species of ‘Least Concern’ by the International Union of Conservation of Nature and Natural Resources, with a stable population.  The American Dipper does not appear on the Alaska Audubon Watchlist (2017).

Other Dipper Species in Alaska: The American Dipper is the only dipper species in Alaska; well okay in all of North America.

Sources of Information:

All About Birds.  Cornell Lab of Ornithology.  Downloaded on 23 November 2018 at: https://www.allaboutbirds.org/guide/American_Dipper/id

Alaska Department of Fish & Game.  Species Profile:  American Dipper.  Downloaded on 23 November 2018 at http://www.adfg.alaska.gov/index.cfm?adfg=americandipper.main

Audubon: Guide to North America Birds. National Audubon Society.  Downloaded on 23 November 2018 at: https://www.audubon.org/field-guide/bird/american-dipper.

Baicich, Paul J. and Harrison, Colin J.O. 1997.  Nests, Eggs, and Nestlings of North American Birds, 2nd Edition. Princeton Field Guides.

BirdLife International. 2016. Cinclus mexicanus. The IUCN Red List of Threatened Species 2016: e.T22708163A94152063. http://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22708163A94152063.en. Downloaded on 25 August 2018.

Dunne, Pete.  2006.  Pete Dunne’s Essential Field Guide Companion:  Comprehensive Resource for Identifying North American Birds.  Houghton Mifflin Company.

Randolph S. Little//Macaulay Library at the Cornell Lab

Warnock, N. 2017. The Alaska WatchList 2017. Audubon Alaska, Anchorage, AK 99501.

William W. H. Gunn//Macaulay Library at the Cornell Lab

It’s A Great Day to Bird

 

Posts navigation

1 2 3 4 5