Table Of ContentShort Communications
Wilson Bulletin, 1 16(1), 2004, pp. 94-97
Intraspecific Brood Parasitism in the Northern Flicker
Allen R. Bower' and Danny J. Ingold^-^
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ABSTRACT. Although intraspecific broodparasit- traspecific egg-dumping in cavity-nesting
ism iscommon in many bird species, including several birds, including primary cavity nesters such as
ohsfeacvioenntrdbaaesrepynecircfeaipvciotrbytr-eondoedsitnpiawnrgoaosbdiiptredicss,kmeiirtnsd.toheeWseNonrrotethpoearrptnpeaFalcriacskte-o fsiltiecskerasr,emoafytenbeincosmhomrotnsuspinpcley s(usieteablBeronewsnt
er (Colaptes aiiratus) in which six to eight eggs were 1984, Raphael and White 1984, Emlen and
dumped into the host nest box during a 2- to 3-week Wrege 1986, Pieman and Belles-Isles 1988, Li
period. We estimate that the host female laid a clutch and Martin 1991). Here, we report an apparent
of 8 to 10 eggs, and at the end of the nestling period instance of intraspecific brood parasitism in a
we confirmed that 16 flicker eggs had been laid in the primary cavity-nesting species, the Northern
nest box. This instance of egg-dumping by a floater
female oranotherresident female in the same territory Flicker. Since the flicker pair in question was
or on an adjacent territory, could have been facilitated not color banded, and because we did not con-
by a lack ofsuitable nest sites in the areacoupled with duct a genetic parentage analysis, we cannot
intense nest-site competition from European Starlings be absolutely certain that egg dumping oc-
{Stunnis vulgaris). Received 16 October2003, accept- curred. There is a remote possibility that the
ed 24 March 2004. paired female may have laid more than one
egg per day, although this has never been re-
ported before in any woodpecker species (see
Intraspecific brood parasitism occurs in a Moore 1995).
wide variety of bird species (Yom-Tov 1980, All observations and nest checks in this
Petrie and Moller 1991, Zink 2000, Andersson study were made by ARB. He observed a pair
and Aehring 2001), and has been documented of nesting Northern Flickers at a nest box in
in several secondary cavity-nesting species in- his back yard in Britton, Lenawee County,
cluding European Starlings {Stiirnus vulgaris', Michigan, from 8 May to 4 July 2003. The
Romagnano et al. 1990, Pinxten et al. 1993, nest box was erected on a pole at a height of
Sandell and Diemer 1999), House Wrens 4.4 m, angled slightly downward (for box di-
{Troglodytes aedotv. Pieman and Belles-Isles mensions see Bower 1994), and was situated
1988), Tree Swallows {Tachycineta bicolor, in a semi-open area about 35 m from the back
Lombardo 1988), Eastern Bluebirds {Sicilia door of his residence. Flickers are considered
sialis'. Meek et al. 1994), Wood Ducks {Aix weak excavators (Harestad and Keisker 1989,
spofisa', Semel and Sherman 2001), and Com- Winkler et al. 1995), and sometimes use
mon Goldeneyes {Biicephala clanguid', Poysa wooden boxes for nesting (Bent 1964, Bower
1999). However, documentation of intraspe- 1995, Ingold 1998). Since European Starlings
cific brood parasitism (e.g., egg-dumping by frequently compete with flickers for nest cav-
a conspecific) in primary cavity-nesting birds ities and boxes (Kerpez and Smith 1990, In-
such as woodpeckers appears to be absent gold 1998), a nest box with a smallerentrance
from the literature. Wiebe (2002) reported an opening (5 cm diameter) designed to live-trap
instance of classical polyandry in the North- starlings was placed on a pole at the same
ern Flicker {Colaptes auratiis) in which a fe- height, 5 m away. This box was erected to lure
male attended two nests concomitantly, but starlings away from the neighboring flicker
there was no evidence ofbrood parasitism. In- box. To furtherdiscourage starlings and attract
flickers, the flicker nest box was completely
^' 2B1io3loNg.yMaDiepnt.S,t.,MBursikttionn,guMmI C4o9l2l2e9g,e,USNAe.w Con- filled with pine woodchips, thus preventing
eord, OH 43762, USA. starling entry and allowing the flickers to “ex-
Corresponding author; e-mail; cavate” a cavity in the box.
[email protected] On 8 May, a pair of Northern Flickers be-
94
SHORT COMMUNICATIONS 95
FIG. 1. Nesting chronology of a Northern Flicker pair in Lenawee County, Michigan, 2003, in which
intraspecific brood parasitism occurred during a period of2.5 weeks. Total number ofeggs and nestlings found
in the nest box on a given day are indicated next to bars. Because it was unclear on 8, 13, and 25 June what
proportion of the eggs and nestlings were attributable to the host versus the parasite, we did not attempt to
indicate this on the graph. It was also unclear whether the dead chick resulted from an egg that was dumped or
laid by the host.
gan excavating woodchips from the flicker havior (continuous sitting) by both a male and
box; they had taken up residency in the box female flicker on 29 May. This was probably
by 1 1 May, although egg-laying had not be- the original mated pair, although we cannot be
gun. Between 1 1 and 15 May, the flicker pair sure since the birds were not marked. On 2
was evicted twice by starlings, in spite of the June, 12 days after the onset ofegg-laying, 12
starling box trap located nearby. After each eggs were found in the box and a single bro-
eviction, the flicker box was repacked with ken egg was found on the ground beneath the
pine chips to discourage the starlings and en- box, possibly having been removed by the
courage the flickers to excavate again. By 22 host pair (removal was not documented).
May, a flicker pair had taken up residency in wSince the birds initiated incubation about 5
the nest box again, although the contents of days earlier, it is possible that a second female
the box were not examined on this day. On flicker dumped an additional egg (the egg on
the afternoon of 24 May, three flicker eggs the ground) or two (the one in the box) be-
were found in the box, suggesting that egg- tween 29 May and 2 June. However, since
laying was initiated on 22 May. On 29 May, flicker incubation typically begins with the
8 days after the initiation of egg-laying, penultimate egg (second-to-last; K. L. Wiebe
1 1
eggs were found in the nest box (Fig. 1). Al- pers. comm.), we assigned one ofthe two eggs
though clutch sizes can range from 3 to 13 to the resident female (egg laid on 30 May),
eggs (see Moore and Koenig 1986, Winkler et and assumed that the other was tiumped be-
al. 1995, Wiebe 2003), female dickers lay tween 30 May and 2 June, rhirtcen llickei
only one egg per day (Sherman 1910, Moore eggs were found in the box on both 4 and (i
1995); thus a second female dicker dumped June, well after the onset of incubation, indi-
at least two and probably three eggs in the cating that another egg had been tIumped in
nest box between 24 and 29 May (Fig. I ). the host box (Fig. I ). On 8 June, seven l-tlay-
ARB first observed apparcfit incubation be- okl flicker nesflings. six unhatchetl eggs and
96 THE WILSON BULLETIN • Vol. 116, No. 1, March 2004
a single dead nestling were found in the box. rather than use nearby, vacant nest boxes. In
This indicates that by 7 or 8 June, an addi- such instances, the benefits of intraspecific
tional egg was dumped into the host box since egg dumping might outweigh the costs of ex-
only 13 eggs were present on 6 June (Fig. 1). cavating a new cavity (assuming a suitable
On 13 June, there were nine nestlings about 6 nest site is available) and starting the nesting
days old and five unhatched eggs (which were cycle over. Wiebe (2003) developed a model
then removed). Since a single dead nestling that demonstrates that even in the face of in-
had been removed on 8 June, our findings of tense starling competition, it virtually always
13 June suggest that an additional egg had benefits flickers to nest early rather than delay
been dumped into the box between 8 and 13 reproduction, except when the risk of cavity
June (nine nestlings, five eggs, and one nest- usurpation by starlings is very high (~75%).
ling that died; Fig. 1). By this point, 15 eggs In any case, egg-dumping should be a profit-
had been laid in the host box, 8 or 9 of which able strategy for the brood parasite because its
were likely laid by the host female. The con- young are reared at no cost. The results ofthis
tents of the box were checked on several oc- study, in which the resident female laid a
casions between 13 and 24 June and on each clutch of 8 or 9 eggs, and ultimately hatched
occasion all nine nestlings were present. On 10 chicks, provide some evidence that intra-
25 June, a large number of mites were found specific brood parasitism may be profitable.
in the nest box; subsequently, the nestlings
ACKNOWLEDGMENTS
were removed and placed in a new box on the
same pole. Upon examining the remaining We thank K. L. Wiebe and two anonymous review-
nest contents of the original box, one addi- ers for their valuable input and J. A. Jackson forfeed-
tional flicker egg was found buried in the back and suggestions that helped to improve this man-
woodchips. Thus, a total of 16 eggs had been uscript.
laid in the nest box during this reproductive
LITERATURE CITED
effort with at least 6 and perhaps as many as
7 or 8 eggs having been dumped by at least Andersson, M. and M. Aehring. 2001. Protein fin-
one additional female. Between 26 June and gerprinting: a new technique reveals extensive
4 July all nine nestlings fledged. conspecific brood parasitism. Ecology 82:1433-
Additional evidence suggesting that an ex- 1442.
tra-pair flicker may have dumped eggs into the Bent, A. C. 1964. Northern Flicker. Pages 264-287 in
Life histories of North American woodpeckers.
resident flicker pair’s nest box occurred on 9 Dover Publications, New York.
June, when a female flicker landed on the roof Bower, A. 1994. Fledging flickers. Bluebird Monitor
of the nest box. This individual put on a con- 8:5.
spicuous display by fanning her tail feathers Bower, A. 1995. Northern Flickers nest successfully
and raising the feathers on the top ofherhead. in a nest box in Michigan. Sialia 17:7-11.
When she peered into the nest box, the male Brown, C. R. 1984. Laying eggs in a neighbor’s nest:
benefit and cost of colonial nesting in swallows.
that was in the box brooding the nestlings ex- Science 224:518-519.
ited and aggressively chased this female to a Emlen, S. T. and P. H. Wrege. 1986. Forced copula-
nearby tree and then further pursued her more tions and intra-specific parasitism: two costs of
than 40 m from the box. About 1 hr later a social living in White-fronted Bee-eater. Ethology
female returned to the box and was again 71:2-29.
chased from the area by the resident male. Harestad, a. S. and D. G. Keisker. 1989. Nest tree
use by primary cavity-nesting birds in south cen-
Intraspecific brood parasitism in Northern
tral British Columbia. Canadian Journal ofZool-
Flickers has not been reported previously. As ogy 67:1067-1073.
in any cavity-nesting species, it is possibly the Ingold, D. J. 1998. The influence ofstarlingson flick-
result of a shortage of suitable nest sites er reproduction when both naturally excavated
(Yom-Tov 1980, Pieman and Belles-Isles cavities and artificial nest boxes are available.
1988, Sandell and Diemer 1999) and/or the Wilson Bulletin 110:218-225.
loss of a nest cavity during the egg-laying or Kerpez, T. a. and N. S. Smith. 1990. Competition
betweenEuropeanStarlingsandnativewoodpeck-
incubation period (Yom-Tov 1980). Ingold ers for nest cavities in saguaros. Auk 107:367-
(1998) found that European Starlings preferto 375.
usurp freshly excavated flicker nest cavities Li, P. and T. E. Martin. 1991. Nest-site selection and
SHORT COMMUNICATIONS 97
nesting success ofcavity-nesting birds in high el- Raphael, M. G. and M. White. 1984. Use of snags
evation forest drainages. Auk 108:405-418. by cavity-nesting birds in the Sierra Nevada.
Lombardo, M. R 1988. Evidence of intraspecific Wildlife Monographs, no. 86.
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letin 100:126-128. 1990. Intraspecific brood parasitism in the Euro-
I Meek, S. B., R. J. Robertson, and P. T. Boag. 1994. pean Starling. Wilson Bulletin 102:279-291.
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! sitism in Eastern Bluebirds revealed by DNA fin- brood parasitism: a strategy for floating females
gerprinting. Auk 111:739-744. in the European Starling. Animal Behaviour 57:
Moore, W. S. 1995. Northern Flicker {Colaptes aii- 197-202.
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Moore, W. S. and W. D. Koenig. 1986. Comparative asitism and nest-site competition in Wood Ducks.
reproductive success of Yellow-shafted, Red- Animal Behaviour 61:787-803.
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intraspecific brood parasitism in the House Wren. avoid nest-site competition: testing a model using
Condor 90:513-514. data from starlings and flickers. Oikos 100:291-
II PiNXTEN, R., O. Hanotte, M. Eens, R. F. Verheyen, 298.
A. A. Dhondt, and T. Burke. 1993. Extra-pair Winkler, H., D. A. Christie, and D. Nurney. 1995.
paternity and intraspecific brood parasitism in the Woodpeckers: a guide to the woodpeckers of the
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from DNA fingerprinting. Animal Behaviour 45: Yom-Tov, Y. 1980. Intraspecific nest parasitism in
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Wilson Bulletin, 116(1), 2004, pp. 97-101
Common Loon Pairs Rear Four-Chick Broods
Steven T. A. Timmermans,’’^ G. Eoin Craigie,' and Kathy E. Jones'
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ABSTRACT. Common Loons (Gavia inuner) nor- ation, or a combination of these factors. Received R
mally lay a single clutch of two eggs each breeding July 2003, accepted 24 March 2004.
season. They occasionally layone-orthree-eggclutch-
es, and rarely, four-egg clutches. Participants of the
Canadian Lakes Loon Survey provided seven indepen-
vStiperniimerary broods, cither as a result of
dent observations of loon pairs rearing four-chick
broods. F’hotographic evidence confirmed two separate nest parasitism by unrelated conspeeilies, su-
instances ofadult loon pairs at Anglin Lake, Saskatch- pernumerary clutches, or post-hatch brood
ewan, and Kasshabog Lake, Ontario, exhibiting paren- amalgamation, are relatively etmimon among
tal behavior toward a four-chick brood. Occurrence of grebes (Storer and Nuechterlein 1902, Cullen
four-chick broods may be the result ofsupernumerary et al. 1999. Muller and Storer 1999. Stout and
clutches, nest parasitism, post-hatch brood amalgam- Nuechterlein 1999. .Steelman 2()()0) and water-
fowl (Alton and Paulus 1992:90, table 3-21;
.Sayler 1992). However, there are few deKu-
ON' BNiOrdEStMudOi,es(’Caannadaad.a, P.O. Box 160, Port Rowan, mented instances of supernumerary broods in
1
-Corresponding author; e-mail: loons (Barr et al. 2()()0), including the me^st
Stimmermans bsc-coc.org widely studied species, the Cemimon Loon
I
