28 min

Golden-crowned Kinglet

(I created this page in 2007 to present at a monthly Thursday evening presentation at the Black Swamp Bird Observatory).

#todo : add references and photos

  • Regulus ("little king") satrapa
  • Among NA birds, only some hummingbirds are smaller.
  • Closely related to Goldcrest of Eurasia
    • GCKI is nearly indistinguishable from Goldcrest.
    • Even their songs are nearly identical.
    • Smallest birds able to endure freezing temps while maintaining body temp > 105 F.
    • GCKI and Goldcrest feet have grooved soles.
      • For hanging on to tips of conifer branches.

Taxonomy

  • RCKI and GCKI have been a puzzle.
    • Originally placed among thrushes and their allies.
    • Were assigned to titmice familly.
    • Thought to be related to Old World warblers.
    • DNA shows kinglets unrelated to above groups. They are unique.
  • Recent studies of kinglet's proteins indicate substantial genetic diffs between the RCKI and GCKI.
    • Diffs large enough to warrant putting them into different genera.
  • GCKI and Goldcrest could be considered the same species.

GCKI Description

  • Neckless, plump, small pointy bill, beady black eyes, no eye-ring.
  • Short, narrow, deeply notched tail.
  • In all plumages, a greenish gray bird with bold black markings on face.
  • Both sexes olive above, whitish (not olive) underparts.
  • White-and-yellowish wing pattern with black and white wing bars.
  • Adults, yellow and orange crown-patch (in female, yellow only), bordered by black.
  • Orange portion of male crown-patch concealed.
  • RCKI is slightly larger, uniformly plainer, less distinctly patterned, overall greener than GCKI.
  • GCKI: L 3 1/2" - 4", WT 0.21 oz (6 g)
  • RCKI: L 4" - 4 1/4", WT 0.23 oz (6.5 g)
  • 4 to 6 subspecies. Differences related to white eyebrow length, upperparts color, underparts color, contrast diffs between wing bars and secondary edges, bill shape.
  • Frequent tower kills indicate nocturnal migration.
  • Short distance migrant; weak flier.
  • Flickr photo search on Golden-crowned Kinglet

Song

  • Rarely sings during migration. - BNA ???
  • Song is easily missed.
  • High-pitched, weak, rising series of thin notes followed by tumbling, chickadee-like, squeaky laughter.
  • The laughing-part is more noticeable than beginning part of song.
  • Call a very high, thin, usually "see-see-see" or "zee-zee-zee".
  • Very high, weak "tip" notes.
  • Also, very short trill-like sound similar to Brown Creeper call.
  • "see-see-see" call more noticeable than song and best way to locate GCKI.
  • RCKI song is lower-pitched, louder, more musical. One of my favorites.
  • RCKI call a husky dry "jidit".

Behavior

  • Extremely active forager, twice as fast as warblers.
  • Prefers conifers year round.
  • Migration at Magee:
    • Seems to prefer bushes and small to mid-sized deciduous trees with a lot of twigs or very small branches packed close together.
    • Also likes bushes and small trees with vines tangled through them.
    • Inspects dead, shriveled up leaves still attached to tree/bush.
    • Picks at the intersection of twigs.
    • Hops from twig to twig.
    • More frequent hovering in pines by hawk tower.
    • Forage anywhere from treetops to the ground; mostly 5' to 30' high; generally higher than RCKI.
    • Usually found in groups of 3 to 10.
    • Both kinglets are fearless; birders at times can get within an arm's length of them.
  • Wing-flicking action while foraging, but less than RCKI.
  • RCKI is more prone to hovering and flycatching.
  • GCKI does more hanging upside down, chickadee-style, than RCKI.
  • GCKI more social than RCKI.
  • GCKI often joins mixed-species foraging flocks during migration and in winter.
    • In winter, associates with chickadees, woodpeckers, titmice, nuthatches, and creepers.
  • GCKI is so-so responder to pishing.
  • GCKI is almost exclusively insectivorous. Rarely eats fruit or seeds.
    • Diet: small beetles, gnats, caterpillars, scale insects, aphids, spiders, insect eggs.

Spring Migration

  • Info from "Birds of Toledo" and "Birds of Ohio".
  • Golden-crowned Kinglet
    • As a result of winter mortality, fewer GCKI pass through Ohio in the spring.
    • Still fairly common to common spring migrants.
    • Most observations of 20 or fewer.
    • Occasional flights of 50-150+ along Lake Erie.
    • Largest spring flights produce counts of 250-350 from western Lake Erie.
    • Maximum one-day count of 350 on April 11, 1992.
    • First migrants appear by March 20-30.
    • Largest concentrations reported during the first three weeks of April.
    • A few linger along Lake Erie through May 7-14.
    • Latest spring departure May 23, 1937.
  • Ruby-crowned Kinglet
    • Most numerous between April 15 and May 10.
    • Largest spring movements total 100-180+ along Lake Erie.
  • My GCKI observations
    • From hawk watching on tower, usually see first migrating GCKI on March 15-20.
    • In 2007, saw first GCKI migrants on March 22.
    • Have had triple-digit GCKI spring days on Magee boardwalk and at RIVP.
    • By approx third week of April, kinglet numbers lean more to the RCKI side.
    • Only one May GCKI sighting on IMBD a few years ago.

Fall Migration

  • Info from "Birds of Toledo" and "Birds of Ohio".
  • Golden-crowned Kinglet
    • Largest numbers of GCKI occur during the fall.
    • Normally return to the lakefront by Septebmer 15-22.
    • Largest concentration of GCKI occur during October.
    • Flights have produced 100-800+ GCKI.
    • Because of an unusual combination of weather conditions on October 7, 1954, at Put-in-Bay, Dr. Milton B. Trautman estimated 25,000 to 50,000 passed over South Bass Island.
  • Ruby-crowned Kinglet
    • Early RCKI return to Lake Erie by August 16-19
    • Migration normally begins during first half of September.
    • Movements of 100-250+ are occasionally encountered, while daily totals normally are 5-40 along the lakefront.
    • RCKI don't congregate in numbers as large as GCKI.
    • One-day count of 400 observed on October 5, 1986, during the monthly count at ONWR.

BNA Misc Migration Info

Direct quotes from the Birds of North America report on the GCKI:

  • Unknown if this species migrates as solitary individuals or in flocks.
  • Few, if any, localities have only migrants.
    • Most localities show overlap between breeding and migration or wintering and migration.
  • We assume that since this species is found in single-species and/or mixed-species flocks during winter, it probably joins such groups during migration.
  • Overlap between residents and migrants also precludes easy determination of what proportion of the species population migrates and how long individuals remain at a stopover site.
  • Long-term banding studies are needed to answer these questions.

Christmas Bird Count

107th Annual Christmas Bird Count - December 14th 2006 to January 5th 2007

  • Fremont Dec 17, 2006 : GCKI=13 RCKI=1
  • Lake Erie Islands Dec 17, 2006 : GCKI=168 RCKI=6
  • Toledo Dec 2006 Info not a Audubon Web site
  • Rudolph-Bowling Green Dec 23, 2006 : GCKI=15 RCKI=0
  • Grand-Rapids/ Waterville Dec 30, 2006: GCKI=170 RCKI=1
  • ONWR Dec 31, 2006 GCKI=28 Ties High RCKI=0

Historical CBC Data for GCKI

For the 80th thru 106th years (1979/80 thru 2005/06)

ONWR CBC GCKI Counts

Dec 23, 1979 - 7
Jan 04, 1981 - 0
Jan 03, 1982 - 0
Jan 02, 1983 - 8
Jan 01, 1984 - 0
Dec 30, 1984 - 2
Jan 05, 1986 - 1
Jan 04, 1987 - 5
Jan 03, 1988 - 7
Jan 01, 1989 - 10
Dec 31, 1989 - 0
Dec 25, 1990 - 8
Dec 25, 1991 - 3
Dec 25, 1992 - 16
Dec 25, 1993 - 4
Dec 25, 1994 - 2
Dec 25, 1995 - 10
Dec 25, 1996 - 0
Dec 25, 1997 - 9
Jan 03, 1999 - 0
Jan 02, 2000 - 0
Dec 31, 2000 - 0
Jan 05, 2002 - 0
Jan 05, 2003 - 5
Jan 04, 2004 - 0
Jan 02, 2005 - 3
Jan 01, 2006 - 1

Toledo CBC GCKI Counts

Dec 16, 1979 - 55
Dec 21, 1980 - 135
Dec 20, 1981 - 12
Dec 19, 1982 - 42
Dec 18, 1983 - 5
Dec 16, 1984 - 18
Dec 22, 1985 - 46
Dec 21, 1986 - 183
Dec 20, 1987 - 35
Dec 18, 1988 - 4
Dec 17, 1989 - 2
Dec 25, 1990 - 11
Dec 25, 1991 - 13
Dec 25, 1992 - 9
Dec 25, 1993 - 12
Dec 25, 1994 - 51
Dec 25, 1995 - 6
Dec 25, 1996 - 0
Dec 25, 1997 - 3
Dec 20, 1998 - 14
Dec 19, 1999 - 5
Dec 17, 2000 - 5
Dec 16, 2001 - 0
Dec 15, 2002 - 7
Dec 14, 2003 - 9
Dec 19, 2004 - 5
Dec 18, 2005 - 2

Grand Rapids-Waterville

Dec 31, 1979 - 101
Dec 20, 1980 - 72
Dec 31, 1981 - 31
Jan 02, 1983 - 24
Dec 31, 1983 - 0
Dec 31, 1984 - 33
Dec 29, 1985 - 55
Dec 20, 1986 - 61
Jan 02, 1988 - 71
Dec 31, 1988 - 41
Dec 30, 1989 - 116
Dec 25, 1990 - 223
Dec 25, 1991 - 142
Dec 25, 1992 - 48
Dec 25, 1993 - 63
Dec 25, 1994 - 51
Dec 25, 1995 - 31
Dec 25, 1996 - 131
Dec 25, 1997 - 131
Jan 02, 1999 - 29
Dec 26, 1999 - 57
Dec 30, 2000 - 83
Dec 29, 2001 - 44
Dec 29, 2002 - 142
Dec 21, 2003 - 9
Jan 02, 2005 - 70
Dec 31, 2005 - 45

My 2007 winter obs

  • 3 GCKI at 577 Foundation in Perrysburg in mid-Jan.
  • 1 GCKI in MBSP campground in late Jan.
  • 3 GCKI on Feb 28 by hawk tower.

My 2004 WBA survey of MSF

  • GCKI observed
    • Jan 10 - xx Temp 10 F
    • Jan 16 - xx Temp 5 F
    • Jan 24 - x Temp 10 F
    • Jan 31 - none Temp 6 F
  • Mostly observed GCKI in pines with chickadees.
  • One morning, a couple GCKI pecked around on the crunchy snow.

Winter GCKI Study

  • Bernd Heinrich
  • U. Vermont biology professor
  • Author of One Man's Owl
  • Cabin in Maine woods where he studied CGKI.
  • Devoted three chapters to GCKI in Jan 2003 book Winter World: The Ingenuity of Animal Survival.

Winter Flocks

Look for chickadees

  • Birds commonly associated with a winter flock of chickadees:
    • Golden-crowned Kinglet
    • Red-breasted Nuthatch
    • White-breasted Nuthatch
    • Brown Creeper
    • Downy Woodpecker
    • Tufted Titmouse
  • Chickadee flocks probably primary attractors for other birds.
    • Other birds are almost never associated with each other in the absence of chickadees.
  • Chickadees are always by far the most numerous and the most noisy of any mixed-species flock.
  • Chickadees easy to spot; others are usually quiet and harder to locate when by themselves.
  • Birds in mixed-species flock work together in search for food and to watch for predators.

GCKI groups

  • Form cohesive winter groups of two to five individuals.
  • Kinglets vocalize often during day to keep group together.
  • Important for group to maintain close contact during the day for huddling at night.
  • Make special calls when approaching their sleeping place.
  • Calls used to attract members of the kinglet foraging group.
  • Group huddles together in protected areas to survive cold nights.
  • Two may be enough.
  • Lost GCKI could meet up with another by finding noisy chickadees.

Kinglet's Feathers

  • GCKI body temp 109 to 111 F.
    • Temp is 5 to 7 F higher than most birds.
  • Laws of physics:
    • Small objects cool quickly
    • Every point within them is close to the surface where heat is lost.
    • Greater the diff between body and air temp, more energy must be expended to keep warm.
    • Smaller the animal, higher energy cost per given body mass.

Rate of Heat Loss

  • Experimentally heated a dead kinglet and then measured its cooling rate.
  • At air temp of -29 F, kinglet body temp of 111 F, during activity, GCKI would have a passive cooling rate of 140 0.067 F/min = 9.38 F/min.
  • Heat production needed to oppose cooling:
    • Multiply cooling rate by body weight and by the specific heat of flesh.
    • Feathered GCKI must expend at least 13 calories per minute to stay warm at -29 F.
    • Conservative est. because calc. does not account for wind, which increases rate of heat loss.

Insulation

  • How much energy do feathers save the bird?
  • Measured plucked kinglet's cooling rate.
  • Cooling rate of naked kinglet 2.5 times greater than fully feathered GCKI.
    • Naked GCKI experiences air temp at least two to three times colder than a feathered one.
    • Due to small size, GCKI would cool approx 60 times faster than a naked 150-pound pig.
  • BTW, a plucked GCKI "looks like a pink cherry on spindly legs."
  • Naked GCKI weighed 5.43 grams
    • body feathers weighed 0.403 grams
    • Wing and tail feathers weighed 0.095 grams
      • GCKI 4.5 times more feather mass committed to insulation than to flight.

GCKI Winter Fuel

  • GCKI insectivorous.
  • They don't eat seeds that sustain finches.
  • Won't visit suet feeder like a Pine Warbler.
  • One report of GCKI eating fruit.
  • Short, weak bills can't reach grubs under bark or buried deep in wood.
  • Bills meant for gleaning insects from twigs.
    • What insects exist in north country winters?
    • How do GCKI find up to 3 times their own body weight of food each winter day?
  • GCKI starve/freeze to death if without food for only 1 or 2 hours in the daytime.
  • GCKI don't forage at night, and they have not been observed caching food.

Prey too tiny to see

  • Kinglet's winter diet used to be a mystery.
  • Originally thought that GCKI ate springtails (Collembola) "snow fleas."
    • Snow fleas can gather by the millions in track depressions in the snow.
    • Nobody seems to know where snow fleas come from or where they go.
    • Heinrich never saw GCKI pay attention to conspicuous mats of snow fleas.
    • Gray Jays have been observed scooping up snow containing snow fleas.
    • Are snow fleas up in the trees where the GCKI spends its time?

Stomach Contents

  • To find out what kinglets eat, Heinrich killed several GCKI to examine their stomach contents.
  • Opened its bean-sized gizzard.
    • Filled to capacity.
    • No springtails.
    • Found partially digested remains (mostly skins) of 39 geometrid ("inch worm") caterpillars.
    • Neither Heinrich nor an entomologist could identify the inch worms.
    • Nobody had ever reported finding caterpillars on trees in the northern winter before.
    • Other GCKI specimens showed the same results.

Caterpillar Hunt

  • In winter, Heinrich and students hammered trees up to six inches in diameter as hard as possible with a heavy, wooden club.
  • Hit fifteen each red spruce, balsam fir, beech, and red and sugar maples
  • The yield from the 75 trees was 13 tiny inch worms, 2 small spiders, and no snow fleas.
    • Caterpillars visible on the snow, but they looked like the needles and debris.
      • They were gray and brown and very small.
      • They matched remains of those found in the kinglet's gizzard.
    • Caterpillars apparently exist on open branches in winter.
      • Serving as winter food for GCKI was not known before.
      • On one bitter cold winter day, Heinrich watched GCKI pick off and eat several caterpillars.

What Kind of Caterpillar

  • Needed to "rear the larva" to determine what caterpillar was.
  • Results from another caterpillar hunt:
    • 87% of sample was geometrid caterpillars.
    • Total of 80 larvae from the total of 180 trees.

Sugar maples 13
Red spruce 11
Beech 19
Pine 30
Balsam Fir 2
Red maple 5

  • After a few failed attempts at raising caterpillars, Heinrich finally successful.
    • Reared to adulthood several larvae collected from sugar maple but fed on balsam fir.
    • Moths were gray-mottled and marked with subtle browns and cream.
    • Moth identified as the well-known, one-spotted variant, Hypagyrtis unipunctata.
      • Wingspan: 4/5 - 1 9/10 in. (2.0 - 4.7 cm)
      • Food plant of this species is reported to be extremely variable, including alders, willow, birch, oak, and balsam fir.
    • Charles V. Covell's book Eastern Moths describes the variant as:
      • "extremely variable sexually, geographically and seasonally."
      • It had not previously been known where the larvae overwinter.

Now have the answer to the GCKI winter energy source question: Caterpillars.

"To care for the welfare of kinglets, it is necessary to care for moths." - Heinrich.

Night Survival

  • GCKI's high death rate results from :
    • living close to the energy edge in wintertime.
    • being weak fliers due to the heavy coat of insulating feathers they wear.
  • Severe winter storms may produce 100% mortality in local areas.
    • Suffered severe decline in the early 1980s in some areas.
      • By the end of the decade it recovered.
    • In S. Illinois (7 Jan 1977), severe winter storm caused 100% mortality in both bottomland and upland forests.

Heinrich quotes

  • "GCKI are as close to an annual bird (in analogy with annual plants that regenerate each year only by seeds) as any bird gets." - Heinrich
  • "Given its minute, twopenny weight (5 to 6 grams), how such an individual could survive the energy on a cold, sixteen-hour-long winter night is an unimaginable marvel from our human perspective -- it defies physics and physiology."

GCKI Fat Stores

  • Jan-Feb 1983 study collected kinglets in Virginia throughout the day.
    • GCKI increased their fat stores during the day.
      • About 0.25 grams at 8 a.m. to about 0.60 grams at 5 p.m.
  • GCKI weigh only half as much as chickadees, but GCKI fat stores are nearly the same in absolute terms as the chickadees.
  • Relative to body size, GCKI put on twice as much fat per day as chickadees.
  • GCKI fat reserves seem too low for bird to survive temps below 32 F.
  • Researchers concluded that GCKI would require approx twice the calories contained in their maximum fat reserves to survive a bitter cold night.

Torpor

  • Deep torpor at night would save energy.
  • Reductions in body temps are likely. Or not.
    • One study, however, that examined this possibility in captive birds found no hypothermia.
    • Heinrich believes that in the wild, at -20 F, GCKI must become hypothermic.
  • Body temp unlikely to be allowed to go much lower than about 50 F.
    • Can't risk losing ability to shiver to keep from freezing solid in subzero temps.
    • "Trick" is to achieve a state close to death, while retaining the ability to respond and come back to life on demand.
  • Heinrich believes GCKI are "likely engage in some torpor, but very deep torpor is probably not an option."
    • "If it should stop shivering for several minutes, it would quickly freeze as solid as a teaspoon full of water." - Heinrich
  • Other info says GCKI do not enter a state of torpor during cold nights.
  • Even if body temp allowed to drop below 50 F, to survive bitter cold, shelter may be required.

Squirrel's Nest

  • In winter, two observers saw GCKI entering a squirrel's nest.
  • If GCKI regularly used such shelter :
    • "In magnitude, it would be the equivalent of them inventing fire, because it would conserve body heat by enormously reducing convective heat loss."
  • Red squirrels eat GCKI.
    • How would a kinglet know if a squirrel nest is uninhabited?
  • Winter 2000-2001, Heinrich examined dozens red and flying squirrel nests in the Maine woods.
    • Found no bird feces inside any nest.
      • Heinrich found Ruffed Grouse fecal pellets in snow caves.
  • Heinrich followed GCKI at dusk over and over but always lost them in the dark.
  • After monitoring a group of GCKI, Heinrich doubted that kinglets overnighted in a squirrel's nest.
  • GCKI may huddle together on the outside of a squirrel's nest.
  • One student in the early morning flushed a couple GCKI out of a brush pile.
  • GCKI may use multiple options for staying warm at night, depending upon habitat and weather.

GCKI Nesting

  • Carlyn and Robert Galati, amateur ornithologists, conducted the most extensive research to date on nesting GCKI in 1954, 1955, 1956, 1957, and 1960.
  • Technical findings of their study published in Galati and Galati (1985).
  • More personal aspects of their study along with their observations published in their 1991 book Golden-crowned Kinglets: Treetop Nesters of the North Woods.
  • Galatis spent 3800 hours studying 19 nests involving 13 different breeding pairs.
  • Four towers (8, 30, 50, and 53 feet in height) were constructed for up-close observation.
  • In addition, three tree platforms were built in trees next to nesting trees.
  • Eleven nests were reached by using spikes, driven into tree trunks.
  • Blinds made out of heavy canvas.
  • Blind fronts had three vertical slits with zippers so that more than one person could view nest activities.
  • GCKI friendly.
    • Female adults at nests allowed the Galatis to reach into the nest and pick them up.
    • The female, and occasionally the male, visited the Galatis in the blind, and even landed on them at times.
    • Visitors to the Galatis' blinds would be greeted by adult GCKI.

Study Locale

  • GCKI nests located in Itasca State Park in northwestern Minnesota.
  • At Itasca, GCKI preferred spruce-tamarack bogs for nesting sites.

Team Studying

  • One observed the nest from the tower while the other observed activities from the ground.
  • Observations were conducted seven days a week to prevent loss of observation continuity during the incubation and nestling cycle.
  • Galatis remained in their towers during thunderstorms.
  • All GCKI nests they observed survived the storms.
  • Three nests were lowered for better study.

Marking Birds and Eggs

  • Eggs, nestlings, and adults marked for individual identification with different colors of acetate-based paint.
  • Adult females were dabbed with a paintbrush while they incubated or brooded the young.
  • Males never brooded, so their tails were touched with a brush when they fed their mates or nestlings.
  • Eggs were marked and weighed just after they were laid and they were weighed again before they hatched, so they could learn if there was weight loss.
  • Galatis marked the nestlings in order to follow their daily feather-tract development and weight increase.
  • Nestlings had to be frequently recolored because the adults would peck off the paint.
  • Color bands were used on the nestling when their legs were sufficiently developed (12 to 14 days).

Incubation Temperature

  • Thermometer pushed upward through the bottom of the nest so the tip of it rested about level with the top of the eggs in the center of the nest.
  • When female returned to nest, temp rose from 95 F to 105 F within a minute.
  • Temp dropped to 92 F when the thermometer was lowered so that its tip was approximately level with the underside of the lowest eggs.
  • Temp rose to 104 F when thermometer tip raised to the top of the eggs again.
  • The nest retained the heat quite efficiently after the female left for short periods.

Sampling Food

  • Food items were taken at three different nests by removing insects with forceps from the adults' bills just before they fed the nestlings.
  • Sometimes the adults would steal the food back.

Controlling predators

  • Predators were removed from around nests under intensive study.
  • Red squirrels were the principal offenders
  • Galatis usually shot them if and when they came within a few feet of the nest.

Associated birds

Nests located in or close to kinglet territories:

  • Boreal Chickadee
  • Blue-gray Gnatcatcher
  • Rose-breasted Grosbeak
  • Chipping Sparrow
  • White-throated Sparrow
  • Blackburnian Warbler
  • Black-throated Green Warbler
  • Golden-winged Warbler
  • Common Yellowthroat
  • Some competed with GCKI for food.
  • Blackburnian warblers and GCKI had skirmishes on occasions.
  • When GCKI male enters another GCKI territory:
    • Males lean forward and down with crown feathers raised.
    • They flick wings and tail.
    • If neither retreats, may lock bills in battle.

The Nest

Territory size

  • Followed singing male and mapping his song perches to determine area size.
  • Measured the outermost points with steel tape.
  • Measurements plotted on map.
  • Territories ranged in size from 2.1 to 6.2 acres.
    • Averaged 4.1 acres per territory.
  • Five territories were bordered on two sides by roads; three had roads on one side.

Nest Construction

  • Galatis did not know if the male, female, or both select the nest site.
    • Appears the female chooses site location.
  • The GCKI studied nested either in the crowns of tall black spruce or balsams firs or on the underside of white spruce branches.
  • Both sexes share in nest building.
    • Female plays the leading role in both collecting and placing materials.
    • Male defends territory.
  • Sixth day after beginning nest construction, the first egg laid.

Nest dimensions

  • Kinglet nests are cup-shaped and deep.
  • Inside rims slightly arched inward.
  • Nest cavity is almost circular.
  • Cup stretches considerably before the nestlings fledge.
  • For five nests observed, the outside diameter increased nearly an inch from before egg hatching to after fledging.

Mean dimensions for five nests shortly before eggs hatched and after nestlings fledged

Nest dimensionInches BeforeInches After
Inside diameter1.612.16
Outside diameter2.953.81
Inside depth1.571.25
Outside depth3.032.00
Wall thickness0.780.51
  • Kinglet's nest is extremely small to accommodate a cowbird.
  • A 1971 report two records of the brown-headed cowbird parasitizing the GCKI.

Nest materials

  • 19 nests collected and analyzed.
  • Most contained lichens scattered throughout the inner and outer walls and bottom.
  • Interior bottoms of the nests were lined with fine strips of paper birch bark, moss, lichen, deer hair, and bird feathers.
  • Outer walls consisted chiefly of mosses, strands of spider's web, cotton grass, parts of insect cocoons, and some unidentifiable brown-colored, stringy, stretchable material.

Nest heights

  • Average height of 19 nests found in Itasca State Park was 50.3 feet.
  • Some nests suspended from twigs; some resting on twigs.
  • All nests well concealed from wind, rainstorms, and sun.
  • Foliage so dense around nests they could not be seen from above or from nest level.
    • Galatis had to part some of the twigs to observe nest activity.
  • The suspended nests were also completely hidden from view from the top or at nest level but could be partially seen from below.

Eggs

  • One egg laid per day on successive days.
  • GCKI lay eggs early in the morning on successive days until the clutch is complete.
  • Brown markings, varying from tiny dots to large blotches, distributed over entire shell, especially around the larger ends.
  • Averaged 13 millimeters long by 10 millimeters wide.
  • All eggs lost weight during incubation, presumablly through evaporation of moisture through the shell.
  • Ave weight 0.6 - 0.7 grams.
  • 13 nests under observation had 9 eggs for the first clutch,
  • 3 nests had 8 eggs in the second clutch.
  • 2 nests contained 9 nestlings when they were found.
  • GCKI lay so many eggs and their nests are so small, the eggs are in two layers.
    • Usually five on the bottom and four on top.

Incubation

  • Only females incubate.
  • Incubation takes approx 15 days.
  • During a 10-minute period that the female was away from her nest one cold morning:
    • Egg surface temp dropped from 104 to 86 F.
    • When she returned egg temp rose to 100 F in only 35 seconds and to 102 F by the end of 15 minutes.
  • Heat applied to eggs ranged from 102 to 105 F.
  • For one incubating female, Carlyn Galati stroked the female's wing and back, and the GCKI closed her eyes and appeared to go to sleep.
  • Male feeds incubating female.

Nestlings

  • Eggs hatch at any time during the day or night.
  • Eggshells are either eaten or removed by both parents.
  • Brooding time after the last egg hatches lasts between 6 and 9 days.
  • Male does greater share feeding nestlings during early part of the first nesting cycle.
    • Female is spending most of her time brooding.
  • 18 days ave. time for nestlings to be in the nest.
  • Initially young are fed by partly digested food.
    • Later, moths, caterpillars, and other insects furnish their diet.
    • They are very fond of spruce bud moths and caterpillars.

Double-clutching

  • The female incubates. The male is the food provider.
  • After eggs hatch, female remains on nest to warm the naked young.
  • The male feeds the whole family.
  • Because of the kinglet's nest being so well insulated, female can soon stop brooding her young and begin building a second nest nearby.
  • Female is soon incubating her second set of eight to ten eggs.
  • Her mate tends the babies of the first brood.
  • Two pairs Galatis observed began second nest on the eighth day after eggs began hatching in first nest.
  • Each female laid her first egg in the second nest on the fourteenth day afer the first egg had hatched in the first nest.
  • Both pairs completed second nests in five days.
  • In each case the first egg was laid in the second nest on the sixth day from the start of nest construction.
  • In both cases the males of both pairs did very little work on the second nest.
  • After starting their second nests, both females left most of the feeding duties to their mates.

Fledging

  • GCKI usually leave nest between 16 to 19 days after hatching.
  • On first day out of nest, both adults feed fledglings of first brood.
  • Then feeding is done almost exclusively by the male because female has begun incubating in her second nest.
  • When fledglings in the first nest gain independence, eggs in the second nest hatch.
  • After second brood fledges, both parents feed young equally.

Nesting and Fledging Success

  • Most frequent causes of mortality among GCKI are predation, starvation, and faulty or infertile eggs.
  • In the Galatis research, GCKI had :
    • hatching success of 87 percent
    • fledgling success of 80 percent.
  • Galatis banded 57 nestlings during the early part of their study.
    • Received no band returns.
    • Nor did they see any bands on the birds during the years following their initial banding.

Ohio Nesting

  • GCKI have expanded their breeding range southward due to ornamental conifer plantings.
  • Ohio's first breeding pairs reported from Columbiana County during 1962-1963.
  • Two summer reports of individual non-breeders from the Cleveland area before 1970.
  • Nesting records reported in 1989 from Columbiana and Portage Counties.
  • Family group discovered in Maumee State Forest in 1990.
  • Breeding reported in early 90's in Summit, Medina, and Lake Counties.
  • Territorial birds reported at Mohican State Forest during 1998.
  • Breeding populations in northeastern counties may total 3-8 pairs.
  • The few reports indicate nesting activities begin during late April or early May.
  • Fledged young have been discovered as early as May 29, but most are noted between mid-June and early-July.
  • 2006 Breeding Bird Survey data for Ohio show no records of nesting GCKI.

Northwest Ohio

  • In May 1991, Tom Kemp discovered Ohio's first GCKI nest in a stand of spruce in Maumee State Forest.
  • In July 1990, Kemp found a family group in Oak Openings Metropark.
  • GCKI May have nested again in OOM in 1992.
  • At least one GCKI found at OOM during the summers of 1993 and 1995.

Conservation Status

  • GCKI not considered to be at risk.
  • CBC data suggests modest population increases in both species.
  • BBS results indicate GCKI has increased in recent decades.
    • Possibly due to reforestation of spruce trees throughout the Northeast.
    • Nesting in planted conifers.
  • Populations may drop after harsh winters.
  • Long-term numbers seem healthy.

Galati and Heinrich Thoughts

Robert Galati asks :

  • Why does a bird with such a low mortality rate double-brood?
  • Why do they produce so many eggs with such a high rate of success?
  • Why are not kinglets living in plaguelike numbers all through the Minnesota north woods?

Bernd Heinrich states :

  • GCKI that leave on migration suffer enormous mortality.
  • High losses also exist by not migrating.
  • 87 percent of the population is on average normally weeded out every year.

-- end --

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