Common Redpoll – November Bird of the Month – 2018

Common Redpoll

(Carduelis flammea)

Photo by Robin Edwards

General Information:  Common Redpolls are common Arctic and sub-Arctic breeders.  Their numbers vary from year to year (irruptions) depending upon on the availability of seed. 

Description:  These small songbirds are members of the finch family and are about 5.25 inches in length.  Females have a red or orange cap, while males have a red cap and red on the breast and sides, with distinctive black chins.  The male and female have streaking of the flanks, rump, and undertail coverts and a yellow bill. 

North American Range:

 

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

Bird Biology:

Preferred Habitat: In winter, the Common Redpoll prefers open woodlands, brushy edges, weedy fields, and is a regular visitor at bird feeders.  During the summer they can be found breeding in varying habitat types: edges of spruce forests, birch stands, mixed conifer and birch, willow thickets, and low tundra shrub.  They avoid dense forest. 

Breeding Season:  Breeding begins in late April in the western states, and June in the east.  The female searches for the nest site and builds the nest on a horizontal branch or in the crotch of a spruce, alder, or willow.  They nest low to the ground.  On the tundra the nest is placed under a rock ledge, in low ground cover, or among driftwood.  

Nest: The nest is cup-shaped, consisting of fine twigs, grasses, and plant stems, and lined with down, feathers, and hair.  In the arctic, old nests may be reused, in which case the female relines the nest.  Pairs will often nest near one another in loose associations.

Eggs and Incubation: Usually 4-5 eggs.  Nestlings are altricial (young are unable to care for themselves when born).  Female incubates the eggs 10-13 days.  Young are tended by both parents. The adult pair remain together and may have from 1-3 broods in a season.  That’s a lot of young ones to take care of each year.

Fledging: The young quickly grow flight feathers and fledge 11-14 days after birth. 

Food Preferences:  Common Redpolls are seed eaters, preferring a seed about the size of their bill.  Birch catkins are a preferred seed source. 

Redpolls do come to feeders, preferring nyjer or thistle seed, but also eating black oil sunflower seed.  They will also scavenge opened seeds left by other birds.

Feeding Methodology:  The Common Redpoll is an active communal forager generally found in flocks. 

Migration:   During a normal year, fall migration begins in late August and extends to early December.  Spring migration is from late February to early June.   Birds migrate during the day and in flocks. 

The Common Redpoll is an irruptive migrant.  They will move south irregularly in winter following patterns in food supply.  Their winter habitat is the northern boreal forest, however every couple of years, redpolls move farther south in winter, occasionally reaching the central or southern United States. Their movements generally correspond to the availability of seeds and population response to increasing numbers.

Photo by Randy Weisser

Vocalizations:

  • Song:  Combination of a trill and twittering.
  • Call:  Swee-ee-et
  • Flight Call:  A dry rattle

Threats:  Climate change is transforming the Common Redpoll habitat.

Fun Facts:

  • During a winter night, the Common Redpoll will tunnel into the snow to stay warm. These tunnels may be more than a 12 inches long and 4 inches under the snow.  Brrrr.
  • The Common Redpoll can pull a string to get to a piece of hanging food. They can shake seeds out birch catkins so the seed falls to the ground where the birds easily eat them.
  • Redpolls have throat pouches where they temporarily store seeds to later take to a protected, warm spot to eat.
  • Some redpolls eat a diet consisting entirely of birch seeds.
  • Redpolls have high-energy needs and can eat up to 42% of their body mass each day.
  • Redpolls are ‘Alaska Hardy’ and have been found to survive in areas where the temperature dips to minus 65 degrees F. That’s cold!!!
  • A redpoll banded in Alaska was recovered in the eastern U.S. A redpoll banded in Belgium was found in China two years later.  Those are long distance trips. 
Photo by Michelle Michaud

Conservation Status:  Common Redpolls are species of least concern, but populations are declining. Their estimated global population is 160 million.

Similar Species in Alaska:  Hoary Redpoll

Sources of Information:

All About Birds.  2017.  Cornell Lab of Ornithology.  Downloaded on 5 June 2018, and 19 July 2018.  https://www.allaboutbirds.org/guide/Common_Redpoll/id

Arthur A. Allen//Macaulay Library at the Cornell Lab

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

Dunn, Jon L. and Adlerfer, Jonathan, Editors.  National Geographic: Field Guide to Birds of North America.  Fifth Edition.  2006. 

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

Geoffrey A. Keller//Macaulay Library at the Cornell Lab

National Audubon Society.  Birds of North America.  Downloaded on 19 July 2018.  https://www.audubon.org/field-guide/bird/common-redpoll

Sibley, David Allen.  2003.  The Sibley Field Guide to Birds of Western North America.  Andrew Stewart Publishing Inc. 

The IUCN Red List of Threatened Species. Version 2018-1. <www.iucnredlist.org>. Downloaded on 19 July 2018.

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

 It’s A Great Day to Bird

 

Northern Saw-whet Owl – October Bird of the Month – 2018

Northern Saw-whet Owl

(Aegolius acadicus)

Photo by Jason Sodergren
Photo by Jason Sodergren

General Information:  The Northern Saw-whet Owl is a small owl about the size of an American Robin.  They are members of the Strigidae family.

North American Range

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

Bird Biology:

Characteristics/Description: Northern Saw-whet Owl is a charismatic small owl – 7.1 to 8.3 inches in height, with a wing span between 16.5 and 18.9 inches – an owl that will fit in the palm of your hand.  Adults are mottled brown with a whitish facial disk and white-spotted head.  Their beak is black and their eyes are yellow.  Juveniles are dark brown with a cinnamon-colored breast and belly.  They have large, rounded heads that lack ear tufts. 

Juvenile Northern Saw-whet Owl. Photo by Mary Frische and Tom Collipy

Preferred Habitat: You’ll only find these owls in the forest, preferring mature forests with an open understory (for foraging).  They prefer deciduous trees for nesting and dense conifers for roosting (the better to hide), with riverside habitat nearby. 

Breeding Season:  Breeding season begins mid-March to mid-April, ending in late June.  They are generally monogamous, however, if there is sufficient food available the male will mate with more than one female.  Males begin calling (incessantly) in late January to attract a mate and to defend its territory. 

Nest:  The females choose the nesting location.  They are secondary cavity nesters (nesting in previously excavated holes – think woodpecker hole) in dead snags.  They are not known to reuse a nest cavity two years in a row. 

The nest is located at the bottom of the cavity, and may consist of wood chips, twigs, moss, hair, and small mammal bones or may even be unlined.   Nest cavities may be anywhere from 8-60 feet off the ground.  The nest hole is generally 3inches wide and 9-18 inches deep. 

Northern Saw-whet Owls also will use nest boxes (see https://nestwatch.org/learn/all-about-birdhouses/birds/northern-saw-whet-owl/ for plans on how to build a nest box).  You might want to consider one for your home, provided you have the right habitat.  If you install a nest box it is helpful to lay some wood chips in the bottom.

Northern Saw-whet Owl in a nest box.  Photo by Mary Frische and Tom Collipy
Photo by Mary Frische and Tom Collipy
Photo by Robin Edwards

Eggs and Incubation:  The female Northern Saw-whet Owl lays between 4-7 eggs (generally 5-6) with a 1 to 3-day interval between each egg, and can have up to two broods per year.  The eggs are incubated by the female for 26-29 days.  The young hatch in intervals, and are taken care of by the female, although the male brings food to the nest during incubation and brooding.  The chicks fledge within three-weeks of hatching at which time the female and male hunt and feed the young. The young are born covered in white down, eyes closed (opening 8-9 days later).  They are semi-helpless when born. 

Fledging:  The young leave the nest 27-35 days after hatching.  However, they remain near the nest and are feed (primarily by the male) for another four weeks or more. 

Food Preferences:  So what do these birds like to eat?  The mostly eat small mammals – mice, shrews, voles, shrew-moles, bats, and the young of chipmunks, squirrels, and gophers. 

All food bets are off during migration, where they supplement their diet with birds – chickadees, juncos, sparrows, wrens, warblers, robins, waxwings, and kinglets.  They may also eat insects such as grasshoppers, moths, beetles, and bugs.i

In the Homer area (coastal), they may also eat intertidal invertebrates, such as amphipods and isopods. 

Feeding Methodology:   These owls hunt at night (nocturnal), using both sight and sound; hunting hunt from a low perch along the forest edge flying silently and low towards prey. 

Roosting:  These birds roost during the daytime in dense vegetation making them difficult to see even though they are typically just above eye level.   

Photo by Mary Frische and Tom Collipy

Migration:  The Northern Saw-whet Owl is both a resident and a long-distance migrant.  They may migrate north/south or in altitude (moving to lower elevations in the winter).  Others may remain in the same location year-round.  These birds migrate at night using known migration routes across the continent.  They are found year-round in Alaska, although their range is quite limited (see range map). 

This owl winters in a variety of woodland habitats, but may also be found in suburban and urban areas.   Spring migration begins late February and continues into May.  Fall migration is from late September to December, peaking in October and early November.

Vocalizations:

Call:  A rhythmic, repetitive toot, toot.

The bird is most vocal before dawn.  During the breeding season the male gives this rhythmic song for hours without a break.

Threats:   Habitat loss due to reduction in mature forests through logging.  Climate change. 

Fun Facts:

  • Kachemak Bay Birder Jason Sodergren of Homer Alaska has been banding Northern Saw-whet Owls at his home since 2009. To date, he has captured and banded 1231 of these cute, little owls – many of them juveniles.  That is a lot of owls coming through the Homer area. 
  • Its name may have come from its call, which has been likened to a saw being sharpened on a whetting stone. 
  • Migrating Northern Saw-whet Owls can cross large bodies of water, e.g. the Great Lakes.
  • The female keeps a very clean nest, however, once she leaves to roost elsewhere (and prior to the young fledging), the young birds can quickly turn that clean nest box into a typical youngsters’ quarters – messy (layers of feces, pellets, and rotting prey parts).

Conservation Status:  The Northern Saw-whet Owl is a common species, with an estimated global breeding population around 2.0 million.

Only the Southern Appalachian Northern Saw-whet Owl population is listed on the Audubon 2014 State of the Birds Watch List.  This population is at risk of becoming threatened or endangered unless conservation actions are undertaken.  South Dakota and North Carolina have listed the birds as species of special concern.

The International Union of Concerned Scientists listed the Northern Saw-whet Owl as a species of least concern, with a declining population trend.

The species is not listed on Alaska Audubon’s Alaska WatchList 2017. 

Similar Species in Alaska:  Boreal Owl, Northern Hawk Owl

Sources of Information:

All About Birds.  2017.  Cornell Lab of Ornithology.   Downloaded on 3 August 2018 at: https://www.allaboutbirds.org/guide/Northern_Saw-whet_Owl/id

Audubon:  Guide to North America Birds.  Downloaded on 6 August 2018 at: https://www.audubon.org/field-guide/bird/northern-saw-whet-owl

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. Aegolius acadicus. The IUCN Red List of Threatened Species 2016: e.T22689366A93228694. http://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22689366A93228694.en. Downloaded on 06 August 2018.

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

Warnock, N. 2017. The Alaska WatchList 2017. Audubon Alaska, Anchorage, AK 99501.  Downloaded on 6 August 2018 at: http://ak.audubon.org/conservation/alaska-watchlist

It’s a Great Day to Bird

 

Common Raven – September Bird of the Month – 2018

Common Raven

(Corvus corax)

(Photo by Robin Edwards)

General Information:  Other than commonly seen, there is nothing ‘common’ about the Common Raven – a member of the Corvidae Family, Order Passeriformes (yes a “songbird”)There are eight subspecies of Raven, with the Common Raven of Alaska sharing the Corvidae Family spotlight with the Northwestern Crow, Gray Jay, Steller’s Jay, and Black-billed Magpie of Homer.

The raven is often described as the ‘Einstein of birds’—exhibiting unique problem-solving abilities and the ability to learn from observed behavior.  The brain of a Common Raven is among the largest of all birds.  And, as if the bird knows it is special and not common, the walk of a raven has been described as a swagger accentuated with a couple of hops as distinguished from the waddling crow.

Range:

https://www.allaboutbirds.org/guide/Common_Raven/maps-range

Bird Biology:

Characteristics:  The Common Raven is a large bird, with glossy black feathers, a large bill, shaggy throat feathers, weighing in at 2.6 pounds, and 25 inches long – not your average Passerine song bird. Juvenile birds lack the shaggy throat feathers.

They are larger than the Northwestern Crow as demonstrated in the photo below.  A good way to distinguish a Common Raven from an American or Northwestern Crow is the by their wedge-shaped tails, best observed in flight. They are long-lived birds.

Northwestern Crow in the foreground, Common Raven in the background

Photo by Randy Weisser

Preferred Habitat: The Common Raven is often distinguished from the Northwestern Crow by habitat selection with the Raven preferring more open countryside areas near forested areas whereas the crow is more habituated to human presence.  However, being an exceptional bird, the raven provides an exception to the rule and is often found on Homer beaches with the reward of a good food supply and open space.

The Raven is adaptable to a wide variety of habitat — at home in the Alaskan Arctic, forest, grassland, and coast.  And, for you ‘snowbirds,’ the Common Raven is even found in the Southwestern, ‘lower 48’, desert.

Breeding Season:  Ravens mate for life.  In interior Alaska, mating behavior is displayed in mid-January with nesting beginning in mid-March.

Nesting:  Nests are large – essentially a pile of sticks, up to five feet in diameter and two feet in height, forming a platform of weaved sticks, and often found in the crouch of a tree or cliff overhang.  The male will salvage sticks or even break off tree limbs three-foot long to contribute to the nest.  The female is the interior designer making an inner cup 5-6 inches deep and 9-12 inches wide.   They generally pick a new nesting area each year. 

Photo by Michelle Michaud

Eggs and Incubation:  The female lays 3-7 eggs with an incubation period of 20-25 days.   The female incubates while the male brings food to the female. The pair has one brood a year.

The chicks are altricial – blind and featherless, thus helpless.  They are ‘nest-bound’ and require the care and feeding by both parents.

Fledging:  The chicks leave the nest about 4 weeks after hatching.  The remain with the parents after they fledge.

Food Preferences: The Common Raven has been described as ‘feeding on practically anything’ in its Omnivore style dietary preferences. They are opportunistic feeders.

The Common Raven is often a major predator, especially taking nest eggs of seabirds.  Foraging is often facilitated by a pair of Ravens as they incorporate clever methods of finding food.

They will cache or hide their food, and raid other ravens’ caches.  They are known to regurgitate undigestable food (think pellets).  Their diet is mostly small mammals, but also berries and other fruit, grains, small invertebrates, amphibians, reptiles (outside of Alaska, of course), and birds.

They will follow a predator’s tracks to a fresh kill; and will tug on the tail feathers of a raptor (such as Bald Eagle) to distract it so it can steal a bite of food.  This activity has been observed on the beach at Anchor Point during the summer fishing season.  Check it out next time you are there.

During the non-breeding season, they may travel up to 30-40 miles from their roost site to feed. 

Roosting:  In winter, Common Ravens may gather in flocks to forage during the day and to roost at night. During the rest of the year, they are often coupled, or in small groups. As many as 800 ravens have been seen in one roost near Fairbanks.  Now that is a lot of ravens.

Migration:  The Common Raven is a year-round resident of Homer – well throughout its range.  It has been the only bird present during the Christmas Bird Count in Barrow.

Vocalizations:  The Common Raven is described as a great mimic and possesses a varied repertoire of social vocalizations.  One study in Alaska showed ravens have more than 30 distinct vocalizations (including mews, whistles, even dripping water sounds).  The most common vocalization is deep guttural or croaking voice – it almost sounds like the Raven is talking to you, or voicing an opinion.  They are talented mimics.

Call:  cr-r-r-ruck 

Flight Call:  Kaw 

Fun Facts (there are a lot of them for the raven):

  • A flock of ravens is called an “unkindness”.
  • Ravens have been described as playful, as an active learning strategy. 
  • They are known to recognize different individuals – both ravens and humans.
  • Juvenile ravens have been observed sliding down snowbanks and rolling in fresh snow, apparently just for fun.
  • Ravens seem to play in the air as well – flying loops, executing rolls, dive-bombing each other.
  • Edgar Allan Poe made the raven famous as a symbol of death.  The raven is a theme in much of Native American mythology. Alaska Natives; Tlingit, Haida, Tsimshian, BellaBella, and Kwakiutl all viewed the raven as the creator of the world and bringer of daylight. The raven is also important in the creation of myths by the Eskimo. The myths of the raven remain a significant social and religious component of Alaska culture.
  • Legend has it that if ravens leave the Tower of London the British Kingdom will fall. 
  • They were once slaughtered as pests (okay not such a “fun” fact). 
  • World’s largest perching bird.
  • North America’s largest songbird.
  • Juveniles do not breed until 3-4 years of age and will often help with feeding the subsequent young of their natal parents.

Conservation Status:  Ravens disappeared from much of the East and Midwest before 1900. In recent decades they have been expanding their range again, especially in the northeast, spreading south into formerly occupied areas.

The International Union of Conservation of Nature lists the Common Raven as a species of Least Concern – trend increasing.  The raven does not appear on the Alaska Audubon’s Alaska Watchlist 2017.  There is an estimated 7.7 million Common Ravens.

Other Raven Species in Alaska: There are no other raven species in Alaska, but other members of the corvid family here include the Northwestern Crow, Steller’s Jay, Gray Jay, and Black-billed Magpie. 

For more information:  The Common Raven has been researched extensively.  Several good books include:

  • Ravens in Winter, by Bernd Heinrich
  • Mind of the Raven by Bernd Heinrich
  • In the Company of Crows and Ravens by John M. Marzluff and Tony Angell

The National Audubon Society has a great video on ravens singing to their mates.  Check it out at:  http://www.audubon.org/news/listen-sweet-soft-warble-common-ravens-sing-their-partners

Sources of Information:

Alaska Department of Fish and Game.  Downloaded on 11 August 2018 at http://www.adfg.alaska.gov/index.cfm?adfg=commonraven.main

American Bird Conservancy.   Downloaded on 11 August 2018 at https://abcbirds.org/bird/common-raven/

Arnold B. van den Berg/Macaulay Library at the Cornell Lab

Cornell Lab of Ornithology.  All About Birds: Common Raven.  Downloaded on 16 May 2018 https://www.allaboutbirds.org/guide/Common_Raven/id

Marzluff, John M. and Tony Angell. 2005.  In the Company of Crows and Ravens. Yale University.

National Audubon, Guide to Birds of North America.  Downloaded on 11 April 2018.  http://www.audubon.org/field-guide/bird/common-raven

National Georgraphic Society.   Downloaded on 11 August 2018 at: https://www.nationalgeographic.com/animals/birds/c/common-raven/

The IUCN Red List of Threatened Species. Version 2017-3. <www.iucnredlist.org>. Downloaded on 16 May 2018.

Sibley, David Allen. 2001. The Sibley Guide to Bird Life and Behavior. Alfred A. Knopf. New York.

Warnock, N. 2017. The Alaska WatchList 2017. Audubon Alaska, Anchorage, AK 99501.  Downloaded on 11 April 2018.

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

It’s A Great Day to Bird

Bird Rhythms – August 2018

Our August Bird Rhythms presentation on KBBI features the Marbled Murrelet – our Bird of the Month, plus what to do if you find a bird with a deformed beak or an injured bird (see our “Home” page for who to contact).  The presentation also addresses what to do for our safety as we live in bear country – alternatives to feeding birds year-round.

Bird Rhythms – July 2018

Carla Stanley talks about the importance of bird habitat for food, water, shelter, and nesting areas to hatch and raise their young.  She also talks about the Kachemak Bay Birders’ Bird of the Month – the Arctic Tern.  To learn more about the Arctic Tern go to: http://kachemakbaybirders.org/blog/category/bird-of-the-month/  (Be sure to scroll down to reach the Arctic Tern post).

What Just Hit My Window?

Most of us have had birds strike/collide with the windows at our home.  We are disheartened by the death or injury of birds when this happens.  But what can we do?  Kachemak Bay Birder, Michelle Michaud lets us know in her recent Homer News article:  https://www.homernews.com/opinion/what-just-hit-my-window/

Find out what you can do, and what others have done, to prevent these window strikes/collisions.

Fishing net on reflective window at Two Sisters Bakery
Poster Paint on Window – easy to wash off.  Be creative.
Fishing net on deck at Carla Stanley’s house.
Window tape on my house.

Photos by Michelle Michaud

Marbled Murrelett – August Bird of the Month

Marbled Murrelet

(Brachyramphus marmoratus)

Photo by Michelle Michaud – Winter Plumage

General Information:  The Marbled Murrelet is small chunky, long-lived seabird.  This bird is unique among aclids, including other murrelets, in that it nests high up in large coastal trees.  In the Pacific Northwest, these species can be found nesting up to 50 miles inland in old-growth forests.   The species has a global population of 385,000, with 70% of the population residing in Alaska.  It is a member of the alcidae family. 

Range:  The Marbled Murrelet can be found along the Pacific coast from northern Baja California out into the Aleutian Islands.  This chunky little seabird can be found year-round in Kachemak Bay and Cook Inlet. 

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

Bird Biology:

Characteristics:   Often found in pairs, but in protected bays in Alaska, the Marbled Murrelet can be found in groups numbering around 50 birds.  In breeding plumage darkish-brown overall.  In non-breeding plumage a black cap and cheep patch, white collar, white scapulars, white breast and vent.  Fairly long bill. 

They forage, loaf, molt, preen, and undertake courtship displays in near-shore marine waters. 

Winter plumage – Photo by Gary Lyon
Breeding Plumage – Photo by USFWS

Preferred Habitat:  This bird spends all of its time on the ocean, except when breeding.  Winters at sea.

Breeding Season:  April through September

Nests:  Moss-covered platforms on large moss-covered limbs in old-growth trees (200+ years old).   In treeless areas in Alaska, the bird nests on the ground or in rocky cavities typically within one-mile of shore, but no more than four-miles from shore. 

Eggs and Incubation: Egg laying begins in April through late June/early July.  Only one egg is laid.  Nestlings are semi-precocial and downy.   The nest is tended by both parents and hatchlings are brooded up to three days (birds stay in the nest). 

Fledging:  The chick leaves the nest 27-28 days following hatching, flying either to sea or a lake near the coast.    

Food Preferences:  Marbled Murrelets are opportunistic feeders, consuming small fish (e.g, Sand Lance, Capelin, Herring) and crustaceans (Shrimp, Mysids, Euphausiids, and Amphipods). 

Feeding Methodology:  Surface diver, foraging in shallow water (100 feet or less).  Uses it wings to swim under water to catch fish.  Prefers waters at the mouth of rivers and glacial streams, however, it can be found foraging 30 miles out from shore. 

Migration:  Some birds move south in the winter. 

Vocalizations:  Call is a high, gull-like squeal.  At dusk a clear “keer, keer, keer” call.    

Threats:  Habitat loss is the primary threat in the lower 48, where more than 95% of its habitat has been logged.  In Alaska, threats include changes in food availability, avian predators, incidental by-catch in gillnet fisheries, and loss of habitat through old-growth logging.  Marbled Murrelets are vulnerable to oil and marine pollution.

Fun Facts:

  • The Marbled Murrelet usually nests in trees greater than 200 years in age – old growth.
  • While the bird was first described in 1789, it wasn’t until almost 200 years later that the first nest of Marbled Murrelet was discovered and formally documented.
  • The Marbled Murrelet was once known as the “Australian Bumble Bee” by fishermen and as the “fogbird” or “fog lark” by loggers.

Conservation Status:  This species is declining and along the Pacific Coast (California, Oregon, and Washington), the species is listed a threatened under the Endangered Species Act.  In Alaska, the Marbled Murrelet is on the Alaska Audubon “Alaska Watchlist 2017 – Red List”.  Species on the “red list” are either have declining or depressed population trends.  Although the Marble Murrelet has declined in population, it population has stabilized over the past decade.

The International Union for Conservation of Nature lists the Marbled Murrelet as endangered; its population trend decreasing. 

Similar Species in Alaska:  In the Alaska, other murrelet species include the Kittletz Murrelet and the Ancient Murrelet.  Occasionally, the Long-billed Murrelet strays into Alaskan waters, including Kachemak Bay (this bird breeds in Siberia).  

Sources of Information:

Audubon, Guide to Birds of North America.  Downloaded on 11 April 2018.  www.audubon.org/field-guide/bird/marbled-murrelet

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

Cornell Lab of Ornithology.  All About Birds – Marbled Murrelet.  https://www.allaboutbirds.org/guide/Marbled_Murrelet/overview  Downloaded on 11 April 2018. 

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

Hank Lentfer//Macaulay Library at the Cornell Lab

International Union for Conservation of Nature.  The IUCN Red List of Threatened Species. Version 2017-3. <www.iucnredlist.org>. Downloaded on 11 April 2018.

Sibley, David Allen.  2003.  The Sibley Field Guide to Birds of Western North America. Andrew Stewart Publishing Inc. 

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

U.S. Fish and Wildlife Service, Pacific Southwest Region, Arcata Office.  Marbled Murrelet Species Profile.  Downloaded on 30 July 2018 at https://www.fws.gov/arcata/es/birds/mm/m_murrelet.html

Warnock, N. 2017. The Alaska WatchList 2017. Audubon Alaska, Anchorage, AK 99501.  Downloaded on 11 April 2018.

It’s A Great Day to Bird

Arctic Tern – July Bird of the Month – 2018

Arctic Tern

(Sterna paradisaea) 

Photo by Michael Boylan

General Information:  This species is also known as the “Mirror-winged Tern” because of its silver gray upperwings, much like a mirror.  It is a common arctic and subarctic breeder, and uncommon pelagic migrant.  A member of the Laridae family, its estimated population is well over 2.0 million birds.  Only 10% of the population is believed to breed in Alaska.  The Arctic Tern goes ‘south’ for the winter – if going to Antarctica is considered ‘going south.’

Range:  Due to its long distance migration, this bird’s range is quite large.  In the spring it migrates from Antarctica to the arctic and subarctic where it breeds.  Come fall, it returns to Antarctic either via a western route or an eastern route.  Most birds migrate via the eastern route. 

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

Bird Biology:

Characteristics: A medium size tern with angular wings and pointed wingtips.  All plumages show pale silvery gray and white primaries (flight feathers) with small dark tips.  In breeding, the adult tern sports a black cap, long deeply forked tail, short red bill, and quite short red legs. In non-breeding plumage the legs and bill are black and the forehead white.

Preferred Habitat: Open ocean, open tundra, open boreal forests, lakes, ponds, marshes, and small rocky islands.  During the winter the terns prefer Antarctic pack ice. 

Breeding Season:  The Arctic Tern is a circumpolar breeder, with breeding beginning in May and June.  Breeding pairs form a monogamous bond during a given breeding season.  They do not breed until they are 3-4 years old. 

Nesting: The Arctic Tern nest in colonies in a variety of habitats: on small, rocky islands – near- shore or off-shore, open tundra, in open boreal forests, and on barrier beaches on the northeastern Atlantic coast. 

Both the male and female build the nest – a shallow hollow often unlined or sparsely lined with debris and plant material, which is added while sitting on the nest – obtained within reach of the nest.  Parents vigorously defend the nest, diving at and striking intruders.

Arctic terns breed on Tern Lake (appropriate name) at the junction of the Seward and Sterling Highways.  Nesting terns can also be found at Potter Marsh outside of Anchorage.  Terns previously nested at the Old Tern Colony on the south-side of the Homer Airport, but disturbance has caused nest abandonment. 

Photo by Michelle Michaud

Eggs and Incubation: Arctic Terns lay between 1-3 eggs, which are incubated by both parents for 21-23 days.  Once hatched, the young are tended by both parents.  Chicks are semi-precocial (eyes open) and downy. 

The young may leave the nest shortly after hatching, but they don’t travel far – staying close to the nest.  Tern chicks can swim at 2 days. 

Fledging: The young take wing (fly) 21-28 days after hatching, but are fed by their parents for much longer (1-2 months).  These birds will not breed the following year, nor do they make the long migration north.  Some may “summer” off the coast of western South America, around Peru.

Food Preferences:  Arctic Terns feed on small fish, generally less than 6-inches in length (e.g., sandlances, sandeels, herring, cod, and smelt).  They may also grab insects from the air or water surface, and are known to eat crustaceans, mollusks, marine worms, earthworms, and on rare occasions berries.

While in Antarctica the terns feed on krill. 

Feeding Methodology:  Often feeds with other terns and gulls on the open ocean, but inland generally feeds along tundra lakes, rivers, and marshes.  The Arctic Tern feeds by plucking food from the water’s surface or by flying upwind, hovering briefly, then diving to catch prey below the water’s surface.  I’m sure we’ve all seen this behavior.

The Arctic Tern may also forages over streams, ponds, lakes, marshes, and coastal waters.  They are very aggressive toward intruders and may steal food from other birds by swooping at them causing the bird to drops its catch. 

Roosting: Commonly perches on rocks, branches emerging from water, logs, and road signs.  Its not uncommon to see an Arctic Tern perched on a road sign along Potter’s Marsh in Anchorage.  They can often be found resting on the water. 

Photo by Carla Stanley

Migration:  Arctic Terns are long-distant migrants, traveling an estimated 31,000 miles during migration.  How far and where a migrant travels depends upon what part of North America the bird spends the breeding season.  Birds in Western North America (our Alaska birds) migrate south across the Pacific Ocean to Antarctica.  Eastern North American birds migrate across the North Atlantic towards Europe and Northern Africa before heading south to Australia, New Zealand, and Antarctica.  During migration they remain out to sea.

Spring migration is from March to early June.  Fall migration is from July to November, peaking August to mid-September. 

Vocalizations:  Foraging or when taking off from the colony, Arctic Terns give a high-pitched “kip” call.  Alarm call:  A shrill or grating scream high in pitch. 

Threats:  Climate change, oil spills, environmental contaminants, predation (rats, cats, dogs, pigs, horses, cattle, etc.), human disturbance at colonies, habitat degradation, and reductions in fish stocks.

Fun Facts:

  • Want to see breeding Arctic Terns then check out Tern Lake at the junction of the Sterling and Seward Highways, with a bonus of possibly seeing an American Dipper at the salmon viewing platform/bridge!
  • Longest migrant – traveling upwards of 31,000 miles per year
  • Some live up to 25 years, which equals more than 600,000 miles of flying in a lifetime (just think of the frequent flyer miles it earns).
  • They molt their wing feathers during our winter, spending much of that time resting on small ice blocks on the edge of the Antarctic pack ice.

Conservation Status:  Alaska Audubon includes the Arctic Tern on its list of Common Species Suspecting to be Declining.  The tern is declining on the Arctic Coastal Plain, but has been increasing on the Yukon Kuskowkim Delta. 

The International Union for Conservation of Nature lists the Arctic Tern as a species of least concern, but noting that the species’ population is declining. 

Similar Tern Species in Alaska: Aleutian Terns are found in Alaska, and occasionally in Kachemak Bay. 

Sources of Information:

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

Cornell Lab of Ornithology.  All About Birds: Arctic Tern.  Downloaded on April 30, 2018.  https://www.allaboutbirds.org/guide/Arctic_Tern/id

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

National Audubon Society.  Edited by Elphick, C., Dunning, Jr. J.B., and Sibley, D.A.  2001.  The Sibley Guide to Bird Life and Behavior.  2001.  Alfred A. Knopf Inc. 

National Audubon Society: Guide to Birds of North America.  http://www.audubon.org/field-guide/bird/arctic-tern.  Downloaded on 3 May 2018. 

Roger Charters/Macaulay Library at the Cornell Lab

Sibley, David Allen.  2003.  The Sibley Field Guide to Birds of Western North America.  Andrew Stewart Publishing Inc. 

The IUCN Red List of Threatened Species. Version 2017-3. <www.iucnredlist.org>. Downloaded on 03 May 2018.

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

It’s A Great Day to Bird

 

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