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Notes

Chipping Sparrow Feeds Young of Eastern Kingbird

Janet Foster and Ron Tozer

On 10 July 1999, Foster discoveredan Eastern Kingbird (Tyrannustyrannus) nest containing threeyoung, near the village of Tweed,Hastings County, Ontario. The nestwas approximately 7 m from theground, in an elm (Ulmus sp.) thatwas about 11 m in height. With theassistance of her husband John,Foster proceeded to set up theirvideo camera on the kingbird nestto obtain footage of the parentsfeeding the young. Within secondsof focussing the 500 mm lens on thenest and rolling the camera, thefirst bird arrived at the nest ... andit was a Chipping Sparrow (Spizellapasserina).

The sparrow stuffed a smallgreen caterpillar into the gapingbeak of a young kingbird, thenhopped onto the nest, and beganwhat at first appeared to be "nestmaintenance". It went all aroundthe nest, poking and probing at thegrasses, vacating only when one ofthe parent kingbirds arrived. Thisamazing occurrence marked thebeginning of four days of filmingand observing the pair of kingbirdsand the Chipping Sparrow as theycared for the three young kingbirds.

One adult kingbird (believed tobe the female, since it brooded theyoung) appeared to pay little or no

attention to the Chipping Sparrow.Frequently this kingbird would perchon an adjacent branch, seemingly notin the least concerned by the pres­ence of the Chipping Sparrow rightin the nest. This seemed highlyunusual, given that kingbirds areknown for their aggressive behav­iour toward other species near theirnests. However, the other adult king­bird (presumed to be the male) wasnot so tolerant; it was seen to dive atthe Chipping Sparrow at least twice,and "snapped" its bill occasionallywhen the Chipping Sparrowapproached the nest during the king­bird's presence. The ChippingSparrow would leave the nest a splitsecond before this kingbird arrived,and return again the moment thisadult departed.

Not long after filming began on10 July, it started to rain. One adult(female?) kingbird settled downover the young to brood, just as theChipping Sparrow arrived withanother green caterpillar. A tinyhead shot out from under thebrooding adult, and the sparrow fedthe caterpillar to the young king­bird. This performance was soonrepeated again, as the ChippingSparrow returned with yet anothergreen caterpillar.

Over the next four days, it

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became apparent that the ChippingSparrow was not only helping withthe feeding and nest maintenance, itwas also removing fecal sacs. At onepoint, John Foster saw the sparroweven "defend" the nest, as it chaseda Black-capped Chickadee (Poecileatricapilla) away from its vicinity.After feeding the young kingbirdsone afternoon, the ChippingSparrow perched on an overheadbranch and sang. Confirmation thatit was indeed a male came later,during viewing of the video footage,when Mary Gartshore detected thesparrow's cloacal protruberance.Gartshore also identified the appar­ent "nest maintenance" by theChipping Sparrow as "mite eating".The sparrow spent considerabletime poking and probing within thekingbird nest structure, apparentlygleaning mites, which it consumed.

By 13 July, the young kingbirdswere hopping out of the nest ontonearby branches. With the nest nowempty, the Chipping Sparrow spenteven more time gleaning mitesfrom within it. The sparrow contin­ued to bring caterpillars to theyoung kingbirds, but not nearly asfrequently. On occasion, an adultkingbird and the three young wouldperch in a row on a branch, with thediminutive Chipping Sparrowperched between two of the young- a remarkable sight!

Foster left for Alberta on a film­ing assignment on 14 July, and so wasunable to continue the observations.However, a friend saw the kingbirdsand the Chipping Sparrow stilltogether in the nest tree on 17 July.

ONTARIO BIRDS AUGUST 2001

Over two hours of video tape wereobtained of this amazing event, andquestions about the frequency ofoccurrence of such behaviour andwhy it would occur were raised.

DiscussionShy (1982) undertook an extensiveliterature search concerning "thefeeding of one bird by another of adifferent species", and summarized140 cases of this "interspecific feed­ing". Adopting birds were repre­sented by 65 species of 22 families,while birds that were fed were rep­resented by 71 species of 22 families(Shy 1982). Skutch (1976) conclud­ed that "the known combinations ofspecies that enter into these rela­tionships are diverse enough to sug­gest that every species of altricialbirds has occasionally helped anoth­er altricial species of somewhat sim­ilar size with which it has been asso­ciated over a wide area for manyyears". So, this behaviour is certain­ly not rare, although it is infrequent­ly observed and reported.

Shy (1982) organized the pub­lished interspecific feeding occur­rences into eight categories basedon "their probable proximate caus­es". Some observations of thisbehaviour involved more than oneof these categories, and there was alarge "miscellaneous" group whichincluded instances where the cir­cumstances were not known or notrecorded. Interspecific feedingsummarized by Shy (1982) occurredin the following types of circum­stances: mixed clutches involvingnest sharing or egg dumping (espe-

chilly in hole-nesting species wherethere is intense competition for nestsites); feeding another species aftertheir own nest or brood wasdestroyed; nests of two specieslocated close together (especiallywhere the nestlings that hatch firstreceive the attention of one or bothbirds of the other pair); the callingand begging of young birds appar­ently triggering the behaviour;feeding orphaned broods; malesfeeding at another species' nestwhile their mates incubated (andsometimes continuing after theirown young hatched); and matelessbirds (either a "single" adoptingbird or a "widowed" parent bird).

Skutch (1976) noted that malebirds are often so eager to feednestlings that they may even offerfood to their unhatched eggs. Thefeeding of a neighbour's offspring"may provide an outlet forrepressed energy", and the nearestnests are likely to belong to someother species (Skutch 1976).Perhaps the most bizarre publishedexample of interspecific feedinginvolved a male Northern Cardinal(Cardinalis cardinalis) that wasobserved feeding seven goldfish(Carassius auratus) in a garden poolfor several days (Lemmons 1956).The goldfish, apparently accus­tomed to being fed by humans,crowded to the edge of the poolwith their mouths open, and the car­dinal (standing on the pool edge)fed them mouthfuls of worms, as canbe seen clearly in a photograph byLemmons (Welty 1963).

In addition to interspecific feed-

81

ing, "less frequent modes of helpingare nest building, incubation, brood­ing the young, cleaning the nest, andallopreening" (Skutch 1976). "Therelations between the helpers andthe parents of the young that theyattend" may be friendly, hostile, orneutral (Skutch 1976).

There have been several pub­lished reports of interspecific feed­ing involving either the ChippingSparrow or the Eastern Kingbirdwith other species, but we wereunable to find any previousaccounts describing feedingbetween these two species. FemaleHouse Sparrows (Passer domesti­cus) were observed feeding fledg­ling Eastern Kingbirds in Kansas(Fitch 1949) and in Louisiana(Hamilton 1952), and the parentkingbirds were not seen in bothcases. In Wisconsin, Snyder (1913)reported the adoption and feedingof a fledged brood of three EasternKingbirds by an unmated EasternWood-Pewee (Contopus virens) forabout 10 days after the kingbirdparents disappeared following anelectrical storm. Finally, Jackson(1941) observed a pair of ChippingSparrows that fed a brood of PurpleFinches (Carpodacus purpureus)and their own young, where thenests were just one tier of branchesapart in a small spruce (Picea sp.).

AcknowledgementsWe appreciated the assistance ofJohn Foster in the field, and the helpof Dan Strickland with references.The comments of Ron Pittaway onan earleir draft were very helpful.

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Figure 1: Chipping Sparrow and young Eastern Kingbirds in nest. Photo by JohnFoster.

Figure 2: Chipping Sparrow feeding young Eastern Kingbird. Photo by John Foster.

ONTARIO BIRDS AUGUST 2001

Literature CitedFitch, H.S. 1949. Sparrow adopts kingbirds.

Auk 66: 368-369.Hamilton, G.D. 1952. English Sparrow feed­

ing young Eastern Kingbirds. Condor 54:316.

Jackson, R.E. 1941. Song Sparrows assumerole of foster parents. Bulletin of theMassachusetts Audubon Society 25:134-135.

Lemmons, P. 1956. Cardinal feeds fishes.Nature Magazine 49: 536.

Shy, M.S. 1982. Interspecific feeding amongbirds: a review. Journal of FieldOrnithology 53: 370-393.

Skutch, A.F. 1976. Parent Birds and TheirYoung. University of Texas Press, Austin,Texas.

Snyder, W.E.1913. The Wood Pewee as a fos­ter parent. Auk 30: 273.

Welty, J.C.1963. The Life of Birds. Alfred A.

Knopf, New York.

Janet Foster, 830 Crookston Road,R.R. 5, Madoc, Ontario KOK 2KO

Ron Tozer, 1017 Spring Lake Road,R.R.1, Dwight, Ontario POA 1HO

83

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VOLUME 19 NUMBER 2

84

Subnival Foraging by a Golden-crowned Kinglet

Ross D. James

Snowfall in temperate or arcticregions of the world presents achallenge to many animals that tryto overwinter there. For birds inparticular, snow covers manysources of food on or close to theground. And unless such snow canbe relatively easily scratched, shak­en, or flicked off food, it is probablynot energetically worthwhile forbirds to move snow in order to findfood. Species such as grouse, spend­ing much of their lives on theground, seem to resort largely towhat is available above the snow,often high in trees. Even ptarmiganthat may burrow into snow to roost,pick at exposed vegetation mainly,although they will scratch throughsoft snow to expose plant foods(Holder and Montgomerie 1993,Hannon et a1. 1998). AlthoughGreat Gray Owls will plunge-diveinto snow to capture rodents (Nero1980), raptors generally wait forfood to appear on the snow.

But quite apart from movingsnow, it is also possible to find foodbeneath snow without moving it, byentering small openings to cavitiesremaining under snow where it hasaccumulated on top of bent-overvegetation. I would expect thatsmall birds regularly foraging onthe ground would readily enter rel­atively light snow-covered spaces.

ONTARIO BIRDS AUGUST 2001

However, in these situations, theywould largely be moving laterally,or nearly so, into spaces canopiedby snow, where some of the vegeta­tion was still visible above the snow.

However, few birds have beenobserved dropping vertically downinto confined spaces in deep snowwhere vegetation is largely or com­pletely buried. This seems to be atopic about which very few obser­vations have ever been made, orusing such subnival spaces throughlong winters seems to be somethingfew birds have exploited to helpthem survive. Common Redpolls(Carduelis flammea) have beenobserved feeding in snow tunnelsduring winter in Alaska, where novegetation was above the snow(Cade 1953). But it does not seemto be known for Snow Buntings(Plectrophenax nivalis) , which read­ily enter burrows among stoneswhere they place their nests. Norhave I found reference to subnivalforaging for any other northern­wintering birds.

ObservationsOn the afternoon of 8 February2001, about 1600h, I was plowingsnow on my driveway through anarea wooded mainly with whitecedar (Thuja occidentalis) , and afew scattered deciduous trees. It

was a winter of heavy snow, with atleast 75 cm accumulated on theground in the open. It had beensnowing all day and tree boughswere heavily laden. The tempera­ture was about minus 3°C, and hadbeen below freezing all day.

I saw a small bird drop into anopening beside a leaning cedarstump and disappear down into thesnow. I stopped the tractor and waswalking closer when it re-emerged,after about 30 seconds, flew aroundme across the driveway, and againdropped into a small hole in thesnow. This time it disappeared forabout one minute. It then flew upinto low branches of the cedars, andI was able to confirm that it was aGolden-crowned Kinglet (Regulussatrapa), as it foraged away in amore usual fashion. The way it flewto the second hole without hesita­tion suggested that it might havebeen there before.

DiscussionGolden-crowned Kinglets havebeen known to forage on theground, but are rarely below 2 m,typically foraging on smallerbranches well up in trees (Ingoldand Galati 1997). They are notknown to roost under snow in win­ter, and my observations were madeat least half an hour or more beforethey might have been expected toroost for the night.

Golden-crowned Kinglets pre­fer to winter where there is typical­ly snow cover of some extent

85

(Lepthien and Bock 1976). In suchareas, there seems to be plenty offood on conifers, and they areopportunistic foragers, taking awide variety of invertebrate items(Heinrich and Bell 1995). Evenamong snow-laden trees, they seemwell adapted to foraging there, so itseems strange that they would beattracted to subnival foraging.

There could also be distinct dis­advantages to foraging in snow cav­erns. Light levels might restrict theirability to forage effectively.Kinglets apparently do not takeinsects hidden from view (Heinrichand Bell 1995). My observationswere made on an overcast day,among cedars, and late in the after­noon, further contributing to lowlight levels. However, as dwellers ofconifer forests, they may be able tosee well in restricted light. Therecould also be mammalian predatorsin subnival spaces, or such preda­tors might trap the birds in there.Weasels and squirrels commonlyenter and use such spaces.

There is a possibility that thisbird was seeking something otherthan food, such as water or veg­etable matter. But, they are notknown to eat vegetable material(Ingold and Galati 1997), and withthe temperature below freezing allday, water may not have been avail­able. However, there are moistplaces in many spots through thislow lying area, and under deepsnow the temperature might havebeen high enough that water could

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have been present. But, just whatthe bird was doing remainsunknown.

Despite some potentialhazards or difficulties, it seems thatmore birds ought to take advantageof subnival spaces for winter forag­ing. It is a thermally protected envi­ronment for them, as well as forsome invertebrate prey that wouldmake searching such spaces worth­while. For seedeaters, it could pro­vide easy access to quality food.That a species such as a kingletwould forage under snow suggestsperhaps subnival foraging is usedmuch more than observed, butremains poorly documented.

Literature CitedCade, T.J. 1953. Sub-nival feeding of the red­

poll in interior Alaska: a possible adapta­tion to the northern winter. Condor 55:43-44.

Hannon, S.J., P.K. Eason, and K. Martin.1998. Willow Ptarmigan (Lagopus lago­pus). In The Birds of North America, No.369 (A. Poole and F. Gill, editors). TheBirds of North America, Philadelphia.

Heinrich, B. and R. Bell. 1995. Winter foodof a small insectivorous bird, the Golden­crowned Kinglet. Wilson Bulletin 107:558-561.

Holder, K. and R. Montgomerie. 1993. RockPtarmigan (Lagopus mutus). In The Birdsof North America, No. 51 (A. Poole and F.Gill, editors). Academy of Natural Sciences,Philadelphia, and American Ornithologists'Union, Washington, nc

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Ingold, J.L. and R. Galati. 1997. Golden­crowned Kinglet (Regulus satrapa). In TheBirds of North America, No. 301 (A. Pooleand F. Gill, editors). Academy of NaturalSciences, Philadelphia, and AmericanOrnithologists' Union, Washington, nc

Lepthien, L.W. and c.E. Bock. 1976. Winterabundance patterns of North Americankinglets. Wilson Bulletin 88: 483-485.

Nero, R.W. 1980. The Great Gray Owl.Phantom of the Northern Forest.Smithsonian Institute Press, Washington,nc

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ONTARIO BIRDS AUGUST 2001

87

Forest Tent Caterpillars and Birds

David H. Elder

Participants in the 1-2 June 2001Ontario Field Ornithologists' bird­ing tour to Rainy River had theopportunity to experience a majorinsect infestation and see its effectson the forests of the area. For thesecond year, Forest Tent Caterpillars(Malacosoma disstria) had com­pletely defoliated the trees in thepredominantly Trembling Aspen(Populus tremuloides) forests. Theyhad also eaten willow (Salix sp.),alder (Alnus sp.) and other shrubs,and left the landscape looking like itwould in November. The occasionalconifer and the ferns and grass in theground cover were the only green­ery in the forests.

Once the caterpillars had eatenall of the leaves on a tree, theymoved to another. This was done bylowering themselves to the groundon a self-produced silken thread,and then crawling to and up anoth­er tree. This species does not build atent. Since millions of caterpillarswere on the move, their threadsabounded in the forest and madewalking therein very unpleasant.

As the tour group was watchinga flock of Pine Siskins (Carduelispinus) in a defoliated aspen standon 1 June, one bird was noticed insome difficulty. This siskin hadbecome entangled in a number ofsilken threads hanging abundantly

from the leafless trees and itsefforts to escape were unsuccessful.Robin Dawes and Darlene Salterbraved the bugs and ticks, enteredthe forest, and were able to capturethe bird. As the rest of the grouplooked on, it took several minutesto disentangle the Pine Siskin fromthe surprisingly strong threads andrelease it.

A week later, another observerreported a Veery (Catharusfuscescens) trailing a skein of cater­pillar threads from one leg as it flewthrough the trees. Although largerand stronger than a Pine Siskin, it isstill possible that the threads couldhave eventually caused the Veerysome trouble.

What other effects does a ForestTent Caterpillar infestation have onthe birds that live in the defoliatedwoodlands? Undoubtedly, they pro­vide some food for some species. Onthe negative side, they eat all theleaves that other insect larvaedepend on and likely reduce foodavailablity for adult and young birds.Since the trees have no leaves, manynests are exposed to the elementsand also likely suffer a higher rate offailure. In addition, birds in generalare more exposed to predators inthe leafless trees.

Of course, the long term effectsof the Forest Tent Caterpillar on

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birds are negligible, as infestationsof this magnitude occur on a cyclicbasis and are a normal part of theforest ecology and evolution in the

area. Still, it was very interesting tosee some of the immediate effectsand to realize the power of theinsect world.

David H. Elder, Box 252, Atikokan, Ontario POT leO

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