Provisioning of Fledgling Conspecifics by Males of the Brood-parasitic Cuckoos Chrysococcyx klaas and C. caprius

2006·2.2 MB·English

by  Irby J Lovette

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Short Communications
The Wilson Journal ofOrnithology 1 18(1):99-101, 2006 1 3
Provisioning of Fledgling Conspecifics by Males of the Brood-parasitic
Cuckoos Chrysococcyx klaas and C. caprius
Irby J. Lovette,14 Dustin R. Rubenstein, -23 and Wilson Nderitu Watetu
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ABSTRACT. Althoughpost-fledgingcarebyadult Over the past century, there have been nu-
males seems unlikely in bird species that are obligate, merous observations of male Chrysococcyx
interspecific brood parasites, there have been numer- cuckoos feeding conspecifics that were
ous reports of adult male Chrysococcyx cuckoos ap-
parently feeding conspecific young. Most researchers thought to be fledglings (Moreau 1944, Fried-
currently view these observations with skepticism, in mann 1968, Iversen and Hill 1983, Rowan
largepartbecauseChrysococcyxandothercuckoospe- 1983). In a literature review of provisioning
ciesengage incourtshipfeeding, and itispossiblethat behavior in brood parasites, Lorenzana and
field observers could mistake adult females receiving Sealy (1998) found 5 records of nestling or
foodfromcourtingmalesforfledglings,especiallygiv- fledgling provisioning by Klaas’s Cuckoo
en the similar appearances of females and juveniles.
Here, we report an observation ofan extended provi- males and 1 1 such records for Diederik Cuck-
sioning bout by an adult male Klaas’s Cuckoo (C. oo males; Friedmann (1968) discusses 12 and
klaas) feeding a conspecific individual with juvenile 15 such records, respectively, including some
plumage and behavior, and we summarize our obser- anecdotal reports. There is apparently only
ev(Cav.tiidocenanspcreoifuisns)diimicinaltaKerseonctyhcaau.trrWmeanelceessupgirgnoevtsihtseitoDhniaitendgte,hreiaknadvCauihcleaknbocloee ocynxeceuqcukivoaolepnrtovriespioorntinogffalefdegmlianlges,Cahnrdysionctohca-t
potential parental care, is present in these brood-para- case, both the female and young were captive
sitic cuckoos at a higherfrequency than currently rec- birds (Millar 1926, Lorenzana and Sealy
ognized.Themechanismthatcausesmalestoassociate 1998). Historically, a number of researchers
with fledglings is unknown, but warrants furtherstudy. (e.g., Moreau 1944, Friedmann 1968) consid-
Received 20 December 2004, accepted 19 September ered parental care to be common in African
2005.
Chrysococcyx cuckoos and believed that the
behavior might be a primitive condition as-
sociated with a relatively recent evolutionary
The genus Chrysococcyx comprises 15 spe- transition to brood parasitism. As researchers
cies of small. Old World cuckoos (Sibley and continued to document the prevalence of
Monroe 1990), of which all are thought to be courtship feeding in these and other cuckoo
obligate brood parasites (Davies 2000). species, more recent authorities (e.g.. Rowan
Klaas’s Cuckoo (C. klaas) has a wide distri- 1983, Irwin 1988, Lorenzana and Sealy 1998,
bution in sub-Saharan Africa, where it is Davies 2000) have suggested that the behavior
known to parasitize a large number ofpasser-
— is either misdirected courtship feeding or the
ine host taxa, often- but not exclusively result of human observers misidentifying
species of Sylviidae and Nectarinidae (Irwin
adult females as fledglings. In practice, these
1988). Similarly, the Diederik Cuckoo (C. ca-
and other possibilities are difficult to exclude.
prius) breeds throughout much ofsub-Saharan
Although the plumages ofadult African Chry-
Africa and has a broad range of hosts, pri-
marily species of Ploceidae (Irwin 1988). sococcyx are highly sexually dimorphic, it is
difficult to distinguish females from juveniles
in the field (Rowan 1983).
1 Cornell Lab. of Ornithology, 159 Sapsucker Here, we report an observation of an ex-
Woods Rd„ Ithaca, NY 14850, USA. tended provisioning bout by an adult male
Uni2vD.e,ptS,eeloefy GN.euMruodbidolHaolgly, Iatnhadca,BeNhYavi1o4r8,53,CoUrnSeAl.l Klaas’s Cuckoo feeding a conspecific individ-
3Mpala Research Centre, Box 555, Nanyuki, Ken- ual with juvenal plumage and behavior, and
we summarize our observations of similar oc-
ya.
4Corresponding author; e-mail: [email protected] currences in the Diederik Cuckoo. These ob-
99
100 THE WILSON JOURNAL OF ORNITHOLOGY • Vol. 118, No. 1, March 2006
servations add to the body of evidence sug- white patch behind the eye and a white throat
—
gesting that male Chrysococcyx cuckoos may marked with substantial, dark barring plum-
engage in intensive provisioning ofjuveniles. age characters more typical ofjuveniles (Irwin
1988).
KLAAS’S CUCKOO
Beginning at 10:08 UTC+3 on 15 August DIEDERIK CUCKOO
WNW WNW
2004, IJL, DRR, and observed an adult On 28 May 2002 at 08:23, observed
male (by plumage) Klaas’s Cuckoo in Lake a male Diederik Cuckoo feeding an apparent
Nakuru National Park, Kenya (00° 22' S, 36° fledgling (based on plumage) at the Mpala Re-
03' E). This bird was foraging at an extremely search Centre, Laikipia, Kenya (00° 17' N,
rapid rate of movement in the open canopy of 36° 54' E). The fledgling was perched about 3
m
a large yellow-barked acacia tree (Acaciaxan- above ground in a Balanites aegyptica tree.
thophloea). After watching the bird for a few During 15 min of observation, the adult fed
minutes, we observed it deliver food to a sec- the fledgling at least four times and continued
ond, sedentary cuckoo in the same tree. We to do so when the observer left the area. On
WNW
noted the time, and for the next 26 min, we 19 May 2003 at 10:15, noted similar
m
were able to keep both cuckoos underconstant behavior at a site 100 from that of the first
focal observation with at least one observer observation. During this observation, an adult
following each bird. This is apparently the male Diederik Cuckoo gleaned insects from
longest-duration period of potential fledgling long grass and fed them to a fledgling (based
provisioning reported for Chrysococcyx on plumage) perched on a nearby acacia. We
(Friedmann 1968). observed the male make six feeding trips be-
During our observation, the adult male fore cattle flushed the birds.
cuckoo continued to forage rapidly within an
DISCUSSION
approximate 40-m radius around the second
cuckoo. The male returned to the second Based on the posture, behavior, and plum-
cuckoo 18 times while carrying food items, age of the Klaas’s Cuckoo that we observed
all of which appeared to be 1- to 3-cm-long being fed by an adult male, it seems highly
lepidopteran larvae gleaned from the foliage likely that it was a recently fledged bird rather
and bark of the acacia. On 16 ofthe 18 visits, than an adult female being courted. We also
the second, more sedentary bird accepted and noted that the adult male engaged in intensive
ate the caterpillar. On each visit, the adult (and, presumably, energetically costly) forag-
male presented the food with his tail slightly ing for an extended period in order to provi-
cocked, but we observed no otherconspicuous sion this individual. Friedmann (1968) consid-
postures or behaviors potentially related to ered provisioning bouts as long as 15 min as
courtship. No copulations or attempted copu- “suggestive of the fact that the catering adult
lations occurred. was not merely indulging in courtship feed-
During our observation, the presumed ju- ing.” Our observation of an intensive provi-
venile moved among four perches, flying 3—4 sioning period of nearly twice that duration
m each time. These flights were notably more further supports this interpretation. In contrast,
fluttery than those of the adult male and ap- courtship feeding in Chrysococcyx typically
peared typical of the weak flight exhibited by involves a series ofstereotyped behaviors that
recently fledged birds. While perched, this we did not observe: the male’s presentation of
bird also assumed the “fluffed” posture typi- food while simultaneously cocking his head
cal of recent fledglings, and it remained sta- and vibrating his wings and tail, postural bow-
tionary between most provisioning visits. The ing movements by the male, vocalizations by
observation ended when the presumed juve- the male or both individuals, or (in some cas-
nile made a similar, but slightly longer flight es) subsequent copulation (Irwin 1988).
into denser foliage and disappeared from our When considered in concert, our observa-
sight. Although the plumages of female and tions and those in dozens of previous reports
immature Klaas’s Cuckoos are variable and describing equivalent behaviors suggest that
overlap (Irwin 1988), we noted at the time males of several African Chrysococcyx cuck-
that the bird being provisioned had a distinct oos may provision fledglings regularly. Post-
SHORT COMMUNICATIONS 101
fledging associations of adults and offspring LITERATURE CITED
also have been documented in other brood-
parasitic taxa, such as the Brown-headed Daviecshe,atNs.. TB..&20A0.0D..CPuocyksoero,s,Locnodwobni,rdsU,nitaendd Koitnhge-r
Cowbird (Molothrus ater\ Hahn and Fleischer dom.
1995). Indeed, previous reports have docu- Friedmann, H. 1968. The evolutionary history of the
mented male Klaas’s and Diederik cuckoos genus Chrysococcyx. U.S. National Museum Bul-
provisioning both pre-volant young and mul- letin, no. 265, Smithsonian Institution, Washing-
tiple fledglings (Moreau 1944, Friedmann ton, D.C.
1968, Lorenzana and Sealy 1998), thus ex- Hahn, D. C. and R. C. Fleischer. 1995. DNA finger-
print similarity between female and juvenile
cluding misidentification of adult females as
We Brown-headedCowbirdstrappedtogether. Animal
sufficient explanation for this behavior. Behaviour 49:1577-1580.
speculate that not only are females sometimes Irwin, M. P. S. 1988. Order Cuculiformes. Pages 58-
misidentified as fledglings, but perhaps older 104 in Birds of Africa, vol. Ill (C. H. Fry, S.
fledglings being provisioned by males are Keith, and E. K. Urban, Eds.). Academic Press,
sometimes mistaken for females being court- London, United Kingdom.
ed. If earlier reports were correct and provi- Iverson, E. and B. Hill. 1983. DiederikCuckoofeeds
fledgling of same species. Bee-eater 34:47.
tsiivoenliyngcoomfmfolendgilnintghsebAyfraidcualnt Cmharlyessociosccreylxa,- Lorepnazraasniat,esJ.feCe.dainngdnSe.stGl.inSgesalayn.d 1fl9e9d8g.liAndgusltofbrthoeoidr
it raises interesting questions about the genetic own species: a review. Journal ofField Ornithol-
relatedness of the interacting individuals and ogy 69:364-375.
their underlying social system. Millar, H. M. 1926. Golden Cuckoo, C. cupilus.
South AfricanJournalofNatural History6:28-29.
ACKNOWLEDGMENTS Moreau, R. E. 1944. Food-bringing by African
Bronze Cuckoos. Ibis 86:98-100.
We thank M. Muchai and the many additional staff Rowan, M. K. 1983. The doves, parrots, louries, and
members of the Department of Ornithology, National cuckoos of Southern Africa. David Philip, Cape
Museums of Kenya who have greatly facilitated our Town, South Africa.
field research in their country. We similarly acknowl- Sibley, C. G. and B. L. Monroe. 1990. Distribution
edge the Kenya Wildlife Service and the Mpala Re- and taxonomy ofbirds ofthe world. Yale Univer-
search Centre forallowing us toconductthis research. sity Press, New Haven, Connecticut.
The Wilson Journal ofOrnithology 118(1):101-104, 2006
Widespread Cannibalism by Fledglings in a Nesting Colony of
Black-crowned Night-Herons
Christina Riehl12
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ABSTRACT. I studied the diet and foraging be- enging. Isolated incidents of cannibalism among
havioroffledgling Black-crowned Night-Herons(Nyc- Black-crowned Night-Herons have been reported pre-
ticorax nycticorax) in a mixed-species nesting colony viously, but not on a colony-wide scale. Received 2
of Black-crowned Night-Herons and Snowy Egrets December2004, accepted 19 September2005.
(Egretta thula) in New Orleans, Louisiana. In 1 of 5
years, cannibalism of nestlings that had fallen or
climbed out of nests was common, accounting for 66
of94(70.2%)preyitemstakenbyfledglings.Juveniles Many researchers have studied the diets of
took youngerconspecifics by both predation and scav- adult and nestling Black-crowned Night-Her-
ons (Nycticorax nycticorax; Bent 1926, Palm-
1 5500 Camp St., New Orleans, LA 70115, USA. er 1962, Wolford and Boag 1971), but there
2Current address: Dept, of Ecology and Evolution- are few data on the diet and foraging behavior
ary Biology, Princeton Univ., Princeton, NJ 08544, of juveniles immediately after leaving the
USA; e-mail: [email protected] nest. Here, I provide the first report of wide-