j. RaptorRes.38(3):263-269¸ 2004 The Raptor ResearchFoundation,Inc.

BREEDING

BIOLOGY

OF THE

GREY-FACEDBUZZARD(BUTASTUR INDICUS) IN NORTHEASTERN CHINA
WEN-HONG

DENG 1

MOE KeyLaboratory
for Biodiversity
ScienceandEcologicalEn•neering,College
ofLife Sciences,
BeijingNormalUniversity,
Beijing,100875China
WEI

GAO

CollegeofLife Sciences,
Northeast
NormalUniversity,
Changchun,
130024China

JI•NG ZHAO
CollegeofLife Sciences,
illin NormalUniversity,
Siping,136000 China
ABSTRACT.--We
studied the breeding biologyof the Grey-facedBuzzard (Butasturindicus)in Zuojia
Nature Reserve,Jinlin province,China from 1996-98. Grey-facedBuzzardsare summerresidentsin
northeastern
China.Nestingsiteswereoccupiedin Marchand annualreoccupancy
was60%.Grey-faced
Buzzardsbuilt newor repairedold nestsin late March and laid eggsin earlyApril. Layingpeakedin

lateApril and spanned32 d (N = 15 clutches).Clutchesconsistedof 3-4 eggs,incubatedfor 33 -+ 1
d predominantly
by the female,to whomthe malebroughtprey.Afteryounghatched,the femalealso
beganhunting.The meanbrood-rearing
periodwas38 -+ 2 d and nestlingfemalesattainedlarger
asymptotic
massthan males,but the lattergrewfastenMalesfledgedat a meanageof 35 d andfemales
at 39 d. Youngwereslightlyheavierthan adultsat fiedging,but the wingchordand tail lengthswere
shorterthan thoseof adults.A total of 50 eggswaslaid in 15 nests(i clutchsize= 3.3), of which80%
hatchedand 90% of the nestlingsfledged.A mean of 2.4 youngfledgedper breedingattempt.Overallnest success
was80%. Causesof nest failure were addled eggsand predation on eggsor nestlingsby
small mammals (e.g., Siberian weasel[Mustelasibe•ica]).

KEYWORDS:Grey-faced
Buzzard;
Butasturindicus;breeding
biology;clutchsize,,
nestlings;
fledglings;
developm•t;, reproductive
success.

BIOLOG•A REPRODUCTIVA DE BUTASTUR INDICUS EN EL NORESTE DE CHINA

REsUMEN.--Estudiamos
la biologlareproductivade Butasturindicusen la reservaNatural de la ProvidenciadeJinlin en Chinadesde1996-98.B. indicus
esun residentede veranoen el norestede China.
Lossitiosde anidacionfueronocupados
en Marzoy la reocupaci6nanualde losnidosfue el 60%. B.
indicusconstruyoo repararolosnidosviejosa finalesde Marzoy pusohuevosa principiosde Abril.E1
pico de la posturaocurri6en Abril y abarco32 dias (N = 15 nidadas).Las nidadasfueronde
huevosincubados33 +- 1 dias, los cualesfueron incubadospredominantementepot la hembra, a lacual el machotraia presas.La media del periodode crecimientofue de 38 _+2 dias,las hembras
obtuvieronuna mayormasacorporalque los machos,pero estoscrecieronmasrSpidamente.Los machosemplumaronen un promediode 35 diasy lashembrasa los 39 dias.Losjuvenilesal emplumar
fueron levementemaspesadosque los adultos.Una media de 50 huevosfue obtenidaen 15 nidos(tamafiode la nidada = 3.3), de loscualesun 80% eclosionaron
y un 90% de lospichonesemplumaron
una mediade 2.4 pichonesemplumados
pot intento reproductivo.
E16xito generalde anidacionfue
de 80%. Las causasdel fracasode anidacionfueron atribuiblesa huevospodridosy ala depredacionde
pichonespot pequefiosmamlferos(Mustelasibe•ica).
[Traducci6n de C6sar Mfirquez]

Among subtropicalbirds,raptorsare one of the about their breeding biology,particularlyin China.
least-studiedgroups,and relativelylittle is known Since 1995, several surveyshave been conducted
to document the distributionand population status
E-mail address:dengwh@bnu.edu.cnof Grey-facedBuzzards (Butasturindicus)during
263

264

DENG ET A•.

VOL. 38, NO. 3

study period. The vegetationwithin the study area wasquite diverse,althoughthe foresttypewassecondaryforest. The seven tree speciesmainly present on the study
area were Mongolian oak (Quercusmongolica),Dahurian
birch (Betula davurica), Manchurian linden (T ilia mand-

schurica),
Japaneseelm (Ulmusjap0nica),Scotchpine (Pinus sylvestris), Korean larch ( Pinuskoraiensis), and Masson
pine (Pinus massoniana;
Deng et al. 1997). In the study
area, Dahurian rose (Rosa dahurica), Korean rose (Rosa

doreana),willowleaf spiraea (Spiraeasalicifolia),ural falsespiraea (Sorbariasorbifolia),and Sakhalin honeysuckle(Loniceramaximowiczii)
dominated the shrub layer.
METHODS

Breeding areas were surveyed by foot periodicallythroughout the breeding seasonto find mated pairs. We
defined nestingsitesas an area where aerial displaying,mating, nest-building,incubating, brooding, and repeated prey-carryingoccurred.An area with a mated pair wasconsidered an occupied nesting site. Observations of
Grey-facedBuzzardsin their breeding areas were madefrom abovecanopylookoutsand ground blinds with thetheir breeding season in Zuojia Nature Reserve, aid of 8-12x binocularsand a spottingscope.We distinnortheastern China. Because of these survey ef- guished mature males, females, and iramatures by theirforts, the species is known from more localities body sizeand plumage color (Deng 1998). The body sizeof maleswassmallerthan that of females.Also,the plumthan ever before in China (Deng et al. 1997). Feng age color of adults was darker than that of iramatures.
et al. (1991) estimated the population at a maxi- We classifieddisplayflight as territorial only if followed
mum of 30 breeding pairs in Zuojia Nature Re- by an encounter between the resident and an intruder
serveand 1000 breeding pairs in northeastern Chi- (Delannoy and Cruz 1988), otherwise interactions between pair members were considered courtship. We esna. The species occurs either in conifer forests, timated above-groundheightsof flying birds in courtshipbroad-leaf forests, or mixed forests. Grey-faced relative to known above-groundheightsof hills and other
Buzzards
are summer
residents
in this area. A vatopographic features. Nest measurements were taken at
rieW of reports suggestthat most Grey-facedBuz- accessiblenests.Nest height wasmeasuredin plumb-line
zards that breed in northeastern China migrate to distancefrom the nest to ground level. Shortestdiameter,
longest nest diameter, nest depth exterior, and nest
Okinawa, Taiwan, the Philippines, Indonesia, and depth interior were measuredusing a ruler.
Malaysiafor wintering (Ching et al. 1989, SeverinWe measured egg dimensions (breadth and length to
the nearest 0.1 mm) with vernier calipers, and deterghaus 1991, Deng et al. 2003).
Until now only two casesof breeding by Grey- mined egg massand body massof nestlings(nearest 0.1g) with a spring scale (Pesola,Barr, Swizerland). Individfaced Buzzardshave been reported in China (Feng ual youngwere marked with colored leg bandssoonafter
et al. 1991, Zheng and Wang 1998), and these only hatching. Ricklefs' (1967) method of fitting equationsto
included brief descriptions. The nests and eggs growth curveswas used to compare growth patterns ofhave been described(Cheng 1987, Xu 1995), and male and female nestlings.Nestlings were weighed, andbreeding territory and roost characteristicshave the length of their wing chord, tail length, culmen, andtarsal length were measured at 3-d intervals. After fiedgbeen reported (Kojima 1982, Deng et al. 1997, ing, mist nets were used to capture fledglings and adults,
2003). Here, we describebreeding biology of Grey- which were measured (tarsal length, wing chord, culmen,
faced Buzzards based on 3 yr of observationsin and tail length) and weighed. Tarsallength wasmeasured
from the intertarsaljoint to the bend of the foot. The
Zuojia Nature Reservein northeastern China.
tail length (mm) was measured from the base to the tip
STU•)¾ APm^of the center rectrix. Reproductiveoutput was the total
number of fledglings produced over a nestling season.
The studyarea,ca. 184 kme in size,waslocatedin Zuo- Reproductive successwas a general term that included
jia Nature Rcserveand included the Tumengling Mounseveralmeasuresand components,expressedon per pair,tains and Zhujia Mountains ranging from the eastern
per breeding attempt, or per egg basis.All statisticalproChangbai Mountains to the western plain (126o1'cedures followed Zar (1999).
127ø2'N, 44ø6'-45ø5'E;Fig. 1). Elevation at the siteranged from 200-500 m above sea level. The climate is RESULTS
east monsoon, characterized by hot, dry summers andCourtship and Territoriality. We observed thecold, snowywinters. Mean monthly temperatures ranged
Figure 1. The distribution of the Grey-facedBuzzard.
Dark shading indicatesbreeding range; grey shading indicates winter ranges. The white square indicates thestudy area.

from -20.5øC in January to 23.6øc in August during

movements and behavior of fledglings for 118 hr

SEPTEMBER2004

GREY-FACEDBUZZARD BREEDING BIOLOGY265

Table 1. Grey-faced Buzzard nest-sitecharacteristicsin northeastern Ghina.
NEST-SITE CHARACTERISTICS

MEAN

SD

RANGE

N

Nest height (m)Nest-treeheight (m)

13.3

3.5

8.8-16.6

15

17.5

3.3

13.5-22.9

15

Nest tree DBH (cm)Shortest nest diameter (cm)Longest nest diameter (cm)

30.8
30.3

9.3
6.2

22.1-44.2
25.5-38.6

15
13

35.1

7.6

28.9-40.3

13

Nest depth exterior (cm)Nest depth interior (cm)Nest support branch diameter (cm)

42.6

11.5

33.7-55.6

13

17.3

8.1

9.8-29.5

13

8.6

3.7

5-18

10

at two nests.Grey-facedBuzzardsare summer res-the pair createda bowl by compactinga layer ofidentsthat establishnestingterritoriesonly during

finer twigswith their talons and breast. The earliest

the breeding seasonin northeastern Ghina. Reoccupancyof nestingsitesoccursin early March. Annual reoccupancywas 60% (N = 15). Six nests
were reoccupied at least twice. Most Grey-faced
Buzzardactivityduring March and earlyApril involved courtshipand territorial displayflights.A
typical courtship flight began when the male cir-nest-buildingactivityin a seasonwas observedon
21 March 1998. The earliest copulation was observedon 29 March 1997, ca. 4 wk before laying.
Copulationusuallyoccurredafter a courtshipdisplay.
More than half (N = 8) of nestswere located in

Korean latches.Neststypicallywere placed in thecled above the nest site and the female followed
upper half (• height = 13.3 m) of relativelytall
shortly afterwards. Both male and female soared trees (x height = 17.5 m; Table 1).
and activelyflew giving intermittent vocalizations.
Egg Laying, Incubation, and Hatching. By lateMalesusedflapping more frequentlythan females April, females remained near the nest site andand circledin the skyhigher than the females.Buz- were mostlyinactive. Males provided food at thiszards reached estimatedabove-groundheights of stageand during the following months. Earliestre30-150 m (• = 80 m, N = 12). Displayboutslasted
corded laying dateswere 20 April 1996, 17 April
5-20 min (x = 14 min, N = 12). Most courtship1997, and 19 April 1998. Layingof first clutches
flights (75%, N = 12) ended with a steepdive into
spanned37 d (17 April-24 May). First clutches
the forests. We observed 11 territorial display
were on average completed on 12 April + 9 dflights in the study area in 1998. Resident males(mean + SD, N = 15 clutches) for 3 yr. Mean
initiated territorial behaviorfrom a perch (N = 7)
clutchsizewas2.9 --- 0.8 (N = 15). Mean egg dior while in flight (N = 4). When intruders enteredmensions were 53.7 X 43.3 mm (N = 47). The
air spacenear the nestingsite, resident malesflew
straight at them and evicted intruders. Buzzards mean egg masswas51.5 g (49.8-53.5 g, N = 47),
only chasedraptorsand relativelylarge birds such 9.9% of the female'sbody mass(x female bodymass = 490 g, N = 6) and 38.2% of her massfor
as corvids.
aclutch of four eggs.
Nest Building and Nest Characteristics.GreyFemales incubated while males provided food.
faced Buzzardsstarted nest building shortly after

occupyingtheir nestingareasin late March or early In 1997,we recordedincubationpatternsof a feApril. Both adults took part in nest construction. male during 12-hr periods (0600-1800 H) for 5
In 1997, during 80 hr of observationat three nests, consecutivedays.The female incubated 22% of thewe observeddeliveriesof 72 dry sticks;malescon- first day (1 egg), 29% of the secondday (2 eggs),
tributed 43 (60%) and females 29 (40%). Most 38% of the third day (3 eggs),39% of the fourthnest building activityoccurred between0600-0730 day (3 eggs),and 43% of the fifth day (4 eggs).
H. Nests were built in trees on forked branches.
Most hatching occurred during late May, except
Buzzardsgathered dry sticksfrom the ground or when pairs renested.Hatching wasasynchronous,
nearby treeswithin 50 m of the nest trees. Several spanning 1-3 d. Hatching for all yearspeaked on
nests contained dried or green needles of Pinus 25 May + 4 d and spanned12 d (20 May-2 June,
spp. in the nest platform. Near nest completion, N = 10). The incubation period from laying to266

DENG ET AL.

VOL. 38, NO. 3

hatching of the last egg averaged 33.5 + 1.6 d (N= 9).

Nestling Period. Young emerged from eggswith
eyesclosed.The eyesbegan to open after 0.5 d. By
the fourth day after hatching, the young could
stand up and showed improved coordination inpecking at food held above them by the female.
Nestlings could be sexed accurately in the nest after they were 8 d old by examining the feather tips
(the primary feather tips of males emerged fromthe sheaths at ca. 8 d, N = 14; females at 9-10 d,

N = 12) and extent of black in wing (males had
more black than females). The first tail feathers

appeared at approximately 12.5 d in males (N =14) and 12 d in females (N = 12). Young began toreplace the natal quill-coverts down 20 d after
hatching.
During the nestling period, males hunted more
frequently than females.However, only femalesdismembered and fed prey to young. Late in the third
week and early in the fourth week after hatching(19-26 d), females spent less time brooding. In
one nest, the female brooded four 18-d-oldyoung
more than half of the time (N = 8 hr), but de-b
600

o FemalesoooßMaleso_o _o

500
400

.o.

• 100VoFemales•
8O , Males.•• •o
60
8•

300

40 •

2OO

20

iO0

•

o

0

10

20

Age

0

30

10

20

Age

(d)

40

d

c

300

30

(d)

_

200

o Femaleso Femalesoaß Males• ßß Males

200 150
100

o

100

5O

,

0

,

Age

,

0

_

(d)

,e

,

,

20

40

Age

(d)

Figure 2. Changes of mass (a) tarsuslength (b) wing
chord length (c) and tail length (d) of males (N = 9)
and females (N = 10) of Grey-facedBuzzardnestlingsin
northeastern

China.

Fledgling and Post-fledglingPeriods. Fledging
spannednearly7 wk, from mid-June-late
July.Aftercreased brooding to 8% (N = 8 hr) when theyoung were 26 d old. From 25-31 d after hatching,
the young squabbled over prey and were able todismembermost softparts.At 26-28 d, the young
flapped their wings regularly and began to roost
overnight in branchesnear the nests.The nestling
period ended when the young flew short distancesfrom the nest and roosted in trees 10-20 m away.
Nine malesfledged at a mean of 35 d of age (range= 33-38, SD = 1.2), and 10 females at 39 d (range

fiedging, young remained in the nest area and returned to the nest frequently. By 42-48 d after
hatching, the young had dispersed50-100 m fromthe nest. Adult femalesstill fed young at this time.
The young were capable of handling and carrying
prey to a perch away from the nest and their siblings. Young constantlysolicitedfood and mobbed(tin-t90) was shorter in males than in females (•vations, the causes for nest failure (N = 5) weremale = 25 d, N = 9; • female = 27 d, N = 10).
Males generally fledged earlier (36-38 d) than fe-

predation on eggsor nestlingsby small mammals

adultswhen

the adults

enteredthe nest area.

At two nest sites, we monitored

movements offive young. One young did not spendtime in the= 37-41, SD = 1.1), with a combinedmean fledg- nest area awayfrom the nest,but dispersedabrupting age of 37 d (range = 31-41, SD = 2).
ly. Four spent 2 d awaybefore their dispersal.The
Growth Rate. Increasein tarsi length, mass,wing agesof young at one nest site averaged76 d (N =and tail length followed Gompertz or logistic 3) and in another 80 d (N = 2) when they disgrowth patterns (Fig. 2). Male and female nestlings persed.Adults and young did not staytogether afshowed differences in mass growth patterns. Fe- ter the latter dispersed.
males attained a higher asymptotic mass than
Reproductive Success.From 1996-98, 18 nests
males (• female = 559 g, N = 10; 2 male = 462 g, were built and 15 nesting attemptswere observed
N = 9). It took males 12.6 d to grow half their (eggs laid; Table 2). In 1.5 nesting attempts,two
asymptoticmass,but 15.1 d for females.The time nest failures occurred during incubation and one•nterval of growth from 10-90% of the asymptote during the nestling stage.According to our obser-

males (37-41 d). Both malesand femalesat fledging were slightlyheavier than adults (adult mass:2
male = 396 _ 11 g, N = 9; • female = 519 ___13
g,N = 10).

(such as the Siberian weasel [Mustda siberica]).
DISCUSSION

Our observation of Grey-faced Buzzard courtship and territorial behavior appearsto differ from

SEPTEMBER2004

GREY-FACEDBUZZARDBREEDINGBIOLOGY

267

Table 2. Annual reproductive successof Grey-facedBuzzardsduring breeding season(1996-98) at Zuojia Nature
Reserve, northeastern China.
PRODUG-

MEAN

EGGS

YOUNG

SUCCESSFULTIVITYNESTINGEGGS

CLUTCHHATCHED

FLEDGEDNESTS NPER NESTYEAR

ATTEMPTS
a

LAID

SIZE

( %)

( %)

( %)

ATTEMPT

1996
1997
1998
Total

4
6
5
15

12
22
16
50

3.0
3.7
3.2
3.3

10 (83)15 (68)14 (87)40 (80)8 (80)
14 (93)14 (100)
36 (90)4 (100)4 (67)
4 (80)
12 (80)

2.0
2.3
2.8
2.4

Number of nestswith eggs.

other Butasturbuzzards.White-eyed Buzzards (B.
teesa)and Rufous-wingedBuzzards(B. liventer)seldom circled above their nest site during the pre-nestingperiod (Smythies1986, Cheng 1987, Xu
1995). GrasshopperBuzzards(B. rufipennis),which
occursin Africa, performed soaringdisplaysabove
the nest site (Rasa 1987, Thiollay and Clobert1990). The behavior of Grey-facedBuzzards circling abovethe nest site during the pairing period
might serveboth to attract potential matesand to
give an assertivemessageto potential intruders.
Grey-facedBuzzardsshowed strong territorial behaviorwhen birds of similar sizeand shapeentered
the territory. We frequently observedchasingbehaviorsof the buzzardsdirected toward congeners,
other raptors,waterfowl, and corvids.
The nesting period was ca. 105 d from nestbuilding to dispersalof youngfrom their natal areas.This is comparableto White-eyedand Rufouswinged buzzards,which have relativelyshort nest-

ing periods(Smythies1986,Cheng1987,Xu 1995,
Gao 2003). Also, the breeding period in Grey-faced
Buzzardsis shorter than that of their tropical coun-terpartsof comparablesize (Newton1979, Mader
1981, Delannoy and Cruz 1988, Thorstrom andQuixch•tn 2000). The nesting cycle of songbirds
alsois longer in tropical than in temperateregions.
Differences between tropical and temperate avian
groupsare due to differencesin the length of timerequired to complete various stagesof breeding(Newton and Marquiss 1982, Delannoy and Cruz
1988). The shorter breeding period of the Greyfaced Buzzardscomparedto that of the White-eyedand Rufous-winged buzzards (Smythies 1986,
Cheng 1987, Xu 1995) resultedfrom shorter periods of nest building, courtship, egg laying, andbrood rearing. White-eyedand Rufous-wingedbuzzards built their nests earlier than the Grey-faced

Buzzards and they had a relatively longer broodrearing period (Cheng 1987, Xu 1995).
It is possiblethat the breeding season,especiallythe laying and nestling period of the Grey-faced
Buzzard, was restricted by food abundance. In
northeastern China, the prey of the buzzards aremainly frogs,reptiles (snakesand lizards), rodents,and somesmallbirds (Deng 1998). We suggestthat
the nestling and fiedging periods in Grey-faced
Buzzardswere synchronizedwith the peak of prey
abundance.

Grey-faced Buzzards preferred to build theirnestsin large Korean larchesand Scotchpineswith
high canopyclosurein wooded areas (Deng et al.
2003). This selection was different from that ofWhite-eyedand Rufous-wingedbuzzards(Xu 1995,
Deng et al. 2003). White-eyed Buzzards usuallybuilt their nestsin broadleaf tree speciesin open
countryor cultivatedareas(Cheng 1987). However, Rufous-winged Buzzards preferred to build
their nestsin conifer or broadleaf tree speciesnear
rivers and swamps in lowland plains (Smythies
1986, Lekagul and Round 1991).
Most raptors select habitat typeswith relatively
open canopyfor easier accessto nests,and fewer
connectionsbetweenneighboring trees,which limits the movements of arboreal animals (e.g., Moore
and Henny 1983, Cerasoli and Penteriani 1996,
Malan

and

Robinson

2001,

Malan

and

Shultz2002). We did not find this selectionpattern in ourstudy.On the contrary, Grey-facedBuzzardsselected their breeding habitat in dense conifer ormixed forests. Thorstrom and Quixch•tn (2000)
suggestedthat denseforesthabitat may limit raptor
hunting behaviors.According to our observations,Grey-facedBuzzardsseldomhunt in the forestnear
nest sites.Their foraging siteswere often in open268

DENG ET AL.

VOL. 38, NO. 3

and Bao-xue Zhang were very patient in helping withdata collection.Earlier draftsof thismanuscriptwereimproved by commentsfrom Zheng-wangZhang and YanFemale nestlingsattained a higher asymptotic yun Zhang. The staff of Zuojia Natural Protection Area
mass than males. However, males left the nests earprovidedlogisticalsupport during the studyperiod. We
her than females. Sexual differences in growth also thank the anonymousreviewersof The Journal ofareassuch as pastures,peat bogs,and paddy fields

near

the

nest sites.

rates have been found in other raptors (e.g.,Schnell 1958, Moss 1979, Delannoy and Cruz

Raptor Research.
LITERATURE

CITED1988).

In this study, during the late nestling period,
young were slightly heavier than adults, and themass decreased slightly at least for females when
the fledgling period began (Fig. 2). This patternalso was found in the Common Buzzard (B. l•teo;

BORTOLOTTI,
G.R. 1986. Evolution of growth ratesin eagles: sibling competition vs. energy considerations.
Ecology
67:182-194.
CERASOLI, M. AND V. PENTERIANI. 1996. Nest-site and ae-

rial point selectionby Common Buzzards(Buteobuteo)
in central Italy.J. RaptorRes.30:130-135.
Xu 1995) and the Upland Buzzard (Buteohemilas- CHENC,T. 1987. A synopsisof the avifaunaof China. Scizus;Gao 2003). Grey-facedBuzzardyoung fledged
ence Press,Beijing, China.
(took their first flight from the nest tree) 31-41 d CHINe, H.C., S.T. Yu, ANt) C.H. CHIANC,.1989. A survey
after hatching. This is comparableto the Rufousof Grey-faced Buzzard Eagle hunting in ManChou
winged Buzzard'srelativelyshortbrood-rearingpeArea. KenTing National Park, Taipei, China.
riod (Gao 2003).
DELANNOY,
C.A. ANDA. CRUZ.1988. Breeding biologyof
the Puerto Rican Sharp-shinnedHawk (AccipiterstriaProductivity seemed high during the study,with
tus venator). Auk 105:649-662.
2.4 young fledged per breeding attempt. High proDEN(;,
W.H. 1998. Breeding ecologyand habitat characductivitywasthe result of a low nest predation rate
teristicsof Grey-faced Buzzard. M.S. thesis,Northeast
and high nestingsuccess(80%). In our study,causNormal Univ., Changchun, China.
es of nest failure were addled eggs (N = 9) and --,W. (•AO, AND G.M. ZHENG. 2003. Nest and roost
predation on eggsor nestlings (N = 8) by mamhabitat characteristicsof the Grey-faced Buzzard inmals such as the Siberianweasel. The

richnessanddensity of animals that prey on Grey-faced Buzzards was low in the studyarea (Deng 1998). Few
mortalities

wereobservedineitheradultsor--,northeasternChina. J. RaptorRes.37:228-235.
X. WANe, ANDW. G,•o. 1997. Breeding habitat
selectionof the Grey-facedBuzzard Eagle.J. Northeast
Norm. Univ. 9:57-61.

young. For example, two adult females banded in

FENG,H.L, G.Q. X•ANc,,AND K.Q. ZH•'4G. 1991. Obser1996 were still on their territories in 1998. Thus, if
vation on breeding Grey-facedBuzzard Eagle. Chinese SciencePublishingHouse, Beijing, China.
a pair of Grey-fhcedBuzzardswassuccessfulin laying eggs, they had a good chance of producing G^o, W. 2003. Ecologyof falcon order in China. Chinese
SciencePress,Beijing, China.
offspring successfully.
KOJIMA,Y. 1982. Territory and territorial behavior of the
There are no data for productivityof other BuGrey-fhced Buzzard Eagle Butasturindicus.Tori Bull
tasturspecies.However, productivityand nesting
Ornithol.Soc.Jpn. 30:117-147.
successwashigher for the Grey-facedBuzzard than
LEg•CUL,B. ANt)P.D. ROUND.1991. A guide to the birds
for the Puerto RicanSharp-shinnedHawk (Accipiterof Thailand. Saha Barn Bhaet, Bangkok,Thailand.
striatus;Delannoy and Cruz 1988), and the Bicol- MArmR,WJ. 1981. Notes on nestingraptorsin the llanosored Hawk (Accipiterbicolor;Thorstrom and Quixch•n 2000). Sharp-shinnedHawkssuffereda higher degree of nest failures fi:om nestling mortality
attributed to parasiteinfkstationand clutch desertion. Bicolored Hawks laid addled eggs and suffered predation on eggs or nestlings.These patterns were consistentwith the general trend thattropical birds have lower fecundity and reproductive successthan their counterpartsin temperateof Venezuela.

Condor 83:48-51.

MALAN, G. AND E.R. ROBINSON. 2001. Nest-site selection

by Black SparrowhawksAccipitermelanoleucus:
imphcationsfor managingexotic pulpwoodand sawlogfo•:
estsin South Atkica. Environ.Manage.28:195-205.
--•Nt)

S. SnULTZ.

2002.

Nest-site

sclectionof theCrowned Hawk-Eagle in the forestsof Kwazulu-natal,
South Africa, and TaL Ivory coast.J. RaptorRes.36.
300-308.

ACKNOWLEDGMENTS

MOORE,K.R. AND CJ. HENNY.1983. Nest site characteristicsof three coexistingaccipiter hawksin northeast
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