MARCH 2002 SHORT COMMUNICATIONS 77 eree for critical review of the •nanuscript,and R.C. Rope -- AND K. NORRDAHI,. 1991. Numerical and function- for providingaerial photographsof the studyarea. al responsesof Kestrels,Short-eared Owls, and Long-

LITERATURE CITED eared OMs to vole densities.Ecology 72:814-826. MARICS,J.S. 1986. Nest-sitecharacteristics and reproduc- BENNET'l,C.M. ] 990. Streamflowlosses and ground-water tive successof Long-cared Owls in southwesternIda- level changesalong the Big Lost River at the Idaho ho. Wilson Bull. 98:547-560. National Engineering Laboratory,Idaho. U.S. Geolog- --, D.L. EVANS,AND D.W. HOLT. 1994. Long-eared ical Survey,Denver, Colorado. Report 90-4067. OM (Asio otus). In A. Poole and F. Gill lEDS.], The CR•O, T.H. 1977. Raptorsof the Idaho National Engi- of North America, No. 133. The Academy of neering Laboratory site. M.S. thesis,Idaho State Uni- Natural Sciences,Philadelphia, PA, and The Amen- vecsit?;Pocatello, ID U.S.A. can Ornithologists Union, Washington, DG U.S.A. 1979. The raptors of the Idaho National Engi- SAUER,J.R., J.E. HINES, I. THOMAS,J. FALLON,AND G. neering Laboratorysite. IDO-12089. U.S. Department COUGH. 2000. The North American breeding of Energy,Idaho Falls, ID U.S.A. survey,results and analysis1966-1999. Version 98.1, --AND G.H. TROST.1979. The biologyand nesting USGS Patuxent Wildlife Center, Laurel, MD U.S.A. density of breeding American Kestrels and Long- eared OMs on the Big Lost River, southeasternidaho. www.mbr. nbs.gov/bbs.html. Wilson Bull. 91:50-61. STONE,M.A.J., LJ. MASS, ANDL.C. KJELSTROM.1993. Sta- HANSEN,R.W. ANDL.D. FLAKE.1995. Ecologicalrelation- tisticalsummaries of streamflowdata tbr selectedgag- ships between nesting Swainson's and Red-tailed ing stations on and near the Idaho National Engi- Hawks in southeastern Idaho. J. RaptorRes. 29:166- neering Laboratory, Idaho, through September 1990. 171. U.S. Geological Survey.Report 92-4196. KORp• 'MXKLE. 1992. Diet composition,prey choice, and breeding successof Long-eared Owls: effects of mul- tiannual fluctuations in food abundance. Can.J. Zool. Received27 October 2000; accepted3 March 2001 70:2373-2381. Associate Editor: Cole Crocker-Bedford

j. RaptorRes. 36 (1) :77-81 ¸ 2002 The Raptor ResearchFoundation, Inc.

BEHAVIORAL AND PHYSICAL DEVELOPMENT OF A NESTLING CRESTED ( MO•H:W:S

DAVID F. WHITACRE ! ThePereg•'ine Fund, 5668 WestFlying Hawk Lane, Boise,ID 83709 U.S.A.

JUVENTINOLOPEZ AVILA AND GREGORIOLOPEZ AVILA FondoPereg•ino, Parque Nacional Tikal, Flores,Petdn,

KEYWORDS: CrestedEagle, Morphnus guianensis;nestling; the species'nesting biology and behavior is based on a behavior,development; nesting biology; tropical single ne•t (Bierregaard 1984). We studied nesting biology, behavior, and diet at two Rates of physicaland behavioraldevelopment in nest- nests of Crested in Guatemala's Petan lowlands ling birds are key aspectsof avian life histories(Starck and Most results are presented elsewhere (Whitacre et al. •n Rickletõ1998). Details of the growth and developmentof pressa, D. Whitacre unpubl. data). Here we describethe many falconiforms are lacking. One such poorly known progressionof behavioraland physicaldevelopment in a speciesis the Crested Eagle (Morphnusg•ianensis). Al- single wild nestling, and present a growth curve and be- though this is the secondlargest of widespreadNeotrop- havioral notes from a captive-rearednestling. ical forest eagles,virtually all that is known concerning STUDY AREA AND METHODS We studied two Crested Eagle nests.Nest No. 1 (1994) 1E-mail address:[email protected] was 7 km south of Tikal National Park, and nest No. 2 78 SHORT COMMUNICATIONS VOL. 36, NO. 1

Table 1. Behavioraland physicaldevelopment of a Crested Eagle nestling at Tikal, Guateinala.

NESTLING AGE (DAYS) DEVEI,OPMENTALFEATURE FIRST NOTED ON THIS DAY 0 Chick mostly immobile; holds head up for brief moments; ate only three bites during all- day watch. 7 Chick moves around more. 9 Chick attempts to shuffle on horizontal tarsi toward female. 16 Chick movesmore easilyacross the nest, shuffling on its tarsi, falling at times;moves into shade provided by female and tree limbs; makes preening motions. 17 Makes preening motions severaltimes; raiseshind end to defecate, with most of mutes fall- ing outside nest. 18 Chick attempts to stand, with the aid of its wings. 23 Standsbriefly on nearly straightenedlegs rather than over horizontal tarsi; takesfaltering steps,though still without legsfully extended;noticeably more activethan during prior week, but still spendsmuch time sprawledout, sleeping. 24 Wing-stretchingbehavior, repeatedly. 25 Chick respondsto distant Keel-billed Toucan (Ramphastossulfuratus) vocalizations by looking in that direction. When male arrivesat nest, chick walkstoward male, flapping wings, bites at prey, and drags prey around nest. Chick attempts,unsuccessfully, to eat in the female's absence;becomes motionless when severalBrown Jays (Cyanocoraxtoorio) ap- proach the nest. 26 When male arriveswith prey, chick vocalizesand attempts to seize prey; tbather shafts emerging on chick'shead and wings. 37 Chick standsfirmly on straightenedlegs and flaps wings as in flight exercise. 38 Chick standssolidly severalseconds at a time; standsup to defecate. 39 When a Black Vulture (Coragypsatratus) flies over the nest, both chick and adult female extend wings and vocalize. 40 Chickjumps as it flaps in place---increasinglycommon thereafter. 44 Feathers appearing on nestling'swings. 45 First time chick wet from rain, the female absent. 46 Chick is so large that the female cannot completely cover it. 51 Nestling standsfor up to 2 min, but spendsmost of time lying in the nest;fed in small bites by the female; female still broodsand sheltersthe chick from sun and rain. 52 Chick remains standingfor 6 min; walksaway from female, remains in the sun for several min. 53 Chick remainsstanding for 17 min. When female arrivesat nest, chick spreadsits wingsand erectsits feathers in apparent threat display.Chick first seen to mantle with wingsspread over prey brought by male; movesnest material around with its beak. 54 Chick again manifestsa defensivedisplay, looking upward with wingsspread and beak open, although we cannot see what elicits this response.Hereafter, chick often respondsto vul- tures in this fashion. Chick standsibr 38 min, is unsuccessfulat feeding itself. 58 Chick extends its wings and calls loudly when a pair of White Hawks (Leucopternisalbicollis) soars over. 59 Chick lowers head and spreadsits wings when two helicopters passoverhead; in subsequent days,airplanes repeatedly elicit this response,sometimes accompanied by gaping of the beak and erected plumage. Chick standsfor >2 hr; is wet from rain, as the female spendsa good portion of the day away;afterwards, chick spreadsits wingsin the sun. Chick first seen to tear off and eat a ikw bites on its own, though with difficulty. 65 Chickjumps and flaps frequently;pounces on and seizesa stick (nest material) with its tal- ons. 72 Chick weighs 1630 g (ca. adult female mass);wing chord is 245 mm, total length 450 mm, and wingspan870 mm; eyesare dark gray,feet buffy yellowish,and cere, facial skin, and beak black. 8O Chick often feeds on its own. MARCH 2002 SHORT COMMUNICATIONS 79

Table 1. Gontinued.

NESTI.ING AGE (DAYS) DEVELOPMENTALFEATURE FIRST NOTED ON Tills DAY 81 Adult female beginsremaining awayfi•om nest most of time and periodicallybrings prey to the nest. Chick adept at plucking prey and feeding itself. Chick now weathersfrequent heavy rains on its own. 92 On 28 August,chick equipped with a backpackradiotransmitter. Chick weighs 1697 g, wing chord is 400 nun, total length 590 ram, and wingspan1140 mm. 93 Chick pouncing, seizingand pecking at nest material and prey remains and exercising wingsmore fi•equentlyand vigorously;commonly jumps, flapping, fi•om rim to rim of the nest, and periodicallytugs at the antenna of its radiotransmitter.When wet from rain, the nestlingoften spreadsits wingsin the sun. lOO Chick fkequentlymoves nest material around with its bill; practicehunting and flapping have reached a fever pitch. 114 On 19 September,nestling flies around within nest tree and to other trees;fledged at 109- 114 d of age (in nest at age 108 d).

(1995) was near the center of the park. Tikal National logged979.3 hr of observationon 83 d; observationpe- Park is a tropicallowland site at 17øNlatitude in Guate- riods averagedl 1.8 hr in duration. We observedthis nest mala's Pet•n Department. Tikal's environment is de- during the last three weeksof the incubation period and scribed by Schulze and Whitacre (1999). Becausenest until the chick fledged at 109-114 days of age. Using a No. 1 failed prior to hatching,we report here on obser- backpack arrangement and 6 •nm teflon ribbon, we vationsat nest No. 2, which produced one fledgling. We placed an 18 g radiotransmitter(216 KHz; Holohil Sys- discoverednest No. 2 on 8 May 1995, while the adults tems Ltd., Carp, Ontario) on the juvenile once it neared were incubating.The nestwas 16.4 m high in a liveJob- fiedging age. We monitored the radio-taggedfledgling dlo tree (Astroniumgraveolens). At a similar height in a until 16 mo of age, when we ended fieldwork. tree 74 m from the nest, we built a wooden observation platfbrm, using poles cut fi•om the fbrest,a 1.2 X 0.6 m RESULTS piece of plywood,and baling wire. Constructionof the The nestling, later judged by size to be a female, was platfbrm took severalhours during three days,fi•om 8- not hatched as of 26 May and wasvery tiny and weak the 10 May. The CrestedEagles gave no indication of being disturbed by the constructionprocess. morning of 29 May; we estimatedshe hatched 28 May, On 1l May we began dawn-to-duskobservations, usu- which was designatedas day 0. The chick's physicaland ally 13-14 hr in duration, using a spotting scope. We behavioral developmentduring the 114 d brood-reanng period are describedin Table 1. Post-FledgingPeriod. At first, the fledgling returned 1200- to the nest to sleep and receive prey, but within a few daysit spent little time in the nest, flying frequently be- 1000- tween various trees up to 100 m fi•om the nest, and re- turned to the nest mainly to receive prey fi•om the adults 800' At this time, the female often fed the chick, bill to bdl. With radiotelemetry,we fbllowed the fledgling to the age 600- of nearly 16 too, when she still remained dependent on the adulls. Unlike some other raptor speciesat Tikal, the

400- fledgling did not indulge in protracted fbod-begg•ng while adults were awayfi•om the nest area, but rather, •t

200- called mainly when they approached. At least as late as day 141 (16 October), the female still occasionallyfed .J the chick bit-by-bitwhen she delivered prey. 0 10 20 30 40 50 60 Data on a Captive-rearedNesfiing. Becauseno growth Days Since Hatching curves are availablefor wild birds, here we report data for a •nale (surgicallysexed) hatched at the Oklahoma Figure 1. Mass gain of' hatchling male Crested Eagle City Zoo (Fig. 1). This male weighed 51 g on hatching (band number = 220107) in the OklahomaCity Zoolog- day, showedessentially linear massgain after two weeks, ical Park. Data fi•om zoo records, courtesy of Barbara and stabilizedat ca. 1117 g at age 42-53 d (Fig. 1). Al- Howard. lowing 5-10% additional massgain thereafter (Newton 80 SHORT COMMUNI(ZATIONS VOL. 36, No. 1

1979:120, T. Cade pers. comm.), its predicted adult (Newton 1979:119). Indeed, the nestling period we doc- weight is ca. 1170-1230 g. At 21 days,this chick's talons umented is equivalent to that of the Philippine Eagle (Pi- were beginning to turn from white to gray, and covert thecophagajefferyi), Crowned Hawk-Eagle( Stephanoaetusco- lkathers were emerging from quills. At four weeks, pri- ronatus), and Martial Eagle (Polemaetusbellicosus), all mary lkathers were emerging from sheaths and at six substantiallylarger birds than the CrestedEagle (Newton weeks the chick was very alert and interested in his sur- 1979:344). It is unclear why the Crested Eagle should roundings.On day 51 he stoodin the nest,on day 72 he have a nestling development period as long as theselarg- sat on the nest rim, and on day 76 he wasfound on the er tropical eagles. Further data are needed in order to floor and returned to the nest. On day 94 the primaries more confidently estimate the duration of the nestling were hard-penned, though the tail was still growing. On period in Morphnus. day 103, the chick flew acrossthe room to another perch, and two dayslater wasflying about the room (B. Howard RESUMEN.--Se observ6 dos nidos de Aguila Monera pets. comm.). Mo•phnusguianensis en Petan, Guatemala. Reportamos sobre el desarrollo comportamiento de un polluelo. Tam- DISCUSSION bian presentamosdatos sobre el crecimiento y compor- Developmental mileposts accord closely between the tamiento de un juvenil en cautiverio. La juvenil silvestre, captive-rearedand wild chicks.Both were able to stand una hembra, eclosion6 aproximadamente 28 Mayo, de- for some time during their seventhweek, and both made signadodia 0. La primera vez que observamosel polluelo their first significantflights at 103-114 days.The Crested arreglarselas plumas fue en dia 16; en dia 17 defec6 hacia la orilla del nido, y siempre lo hizo asi despuas.Dia Eagle nestling at Tikal developed at a slower rate than 18 intent6 pararse por primera vez, yen dia 23 pudo d•d Ornate Hawk-Eagle(Spizaetus ornatus) nestlings (Whi- pararse brevamente. En dia 24 estir6 las alas de manera racre et al. in press b), which in turn developed more estereotipica.A partir del dia 25, respondi6 agresivamen- slowly than did Black Hawk-Eagle nestlings (S. tyrannus; te cuando el macho trajo presa, y a especiestal como Whiracre et al. in pressc). We observedchicks first stand- buitres.A partir del d/a 37 el polluelo logr6 pararsepot ing up for prolonged periods at 5 wk in the Black Hawk- un buen rato, y bari6 las alasen qjercicio.En dia 59, logr6 Eagle, during the seventhweek in the Ornate Hawk-Ea- alimentarse ella mismo por primera vez, y qued6 parada gle, and at 8 wk in the CrestedEagle. Chicksfirst flapped por dos horas. Cuando el polluelo tenla 81 dias, la hem- •n place vigorouslyat 4 wk in the Black Hawk-Eagle,5 wk bra adulta empez6 a ausentarsela mayor parte del dla, m the Ornate Hawk-Eagle,and during the seventhweek supuestamente cazando, y trajo presas al nido periodi- m the Crested Eagle. The age at which we noted chicks camente.A partir del dia 93, el polluelo frecuentemente first able to feed themselves was less variable; this oc- salt6, aleteando, de una orilla del nido a la otra, mane- curred at 8 wk in the Black Hawk-Eagle and during the jaba palitos del nido en su pico, y las atacaba con las ninth week for both the Ornate Hawk-Eagleand Crested garras como que fueran presa. Entre dias 109 y 114, vol6 Eagle. A Black Hawk-Eagle chick first walked out onto fuera del •trbol del nido por primera vez, pero sigui6 hmbs near the nest early in the fourth week and did so regresandoal arbol del nido para recibir presas.Usando commonly by the end of the fourth week. We observed radio-telemetrfa, seguimosla juvenil hasta 16 meses de th•s behavior at 9 wk in the Ornate Hawk-Eagle and 16 edad, cuando terminamos el estudio. En aquella fecha, wk in the Crested Eagle. First flights within the nest tree la juvenil quedaba rodavia dependiente en los adultos. were observed during the eighth week for the Black Hacemos comparaciones entre la rapidez de desarrollo Hawk-Eagle, the tenth week in the Ornate Hawk-Eagle, del Aguila Monera, el Aguilucho de Penacho (Spizaetus and at 16 wk in the Crested Eagle. Fledging from the ornatus),y el Aguilucho Negro (S. tyrannus).E1 desarrollo nest tree took place during the tenth week in the two del juvenil de Mo•phnusf•te lento en comparaci6n con hawk-eaglesand at 16 wk in the Crested Eagle. otros rapacesde ig.ual tamafio. The relative speed of developmentof the abovethree [Traducci6n de los autores] speciesaccords with their relative body sizes.Black Hawk- Eagles (most rapid to develop) are also smallest, with ACKNOWI.EDGMF. NTS mean adult fkmale massof 1115 g (Whitacre et al. in This is an offering of The Peregrine Fund's Maya Pro- press c). Ornate Hawk-Eagles,with intermediate rate of ject; we are grateful to the many individualsand foun- development, are i•atermediate in size, with females av- dations that provided funding for that prqject. We are eraging 1450 g (Whitacre et al. in pressb). Crested Ea- grateful to Barbara Howard fbr providing records for CrestedEagles at the Oklahoma City ZoologicalPark and gles, slowestto develop, have a mean adult female mass to R. Bierregaard,J. Bednarz, and an anonymousreview- of about 1850 g (Whitacre ct al. i•l pressa). er for helpful comments on the manuscript. The nestling periods of these two Crested Eagles (103- 105 d fbr the captive bird and 109-114 d for the wild LITERATURE CITED b•rd) are notablylong for a raptor of this size.The Crest- BIERREGAARD,R.O., JR. 1984. Observationsof the nesting cd Eagle falls well above the curve relating nestling pe- biology of the Guiana Crested Eagle (Movphnusguia- riod to female mass in a wide range of falconiforms hensis). Wilson Bull. 96:1-5. MARCH 2002 SHORT COMMUNICATIONS 81

NEWTON,I. 1979.Population ecology of raptors.T. & A.D. ,J.A. M_xDmOM., H.D. MA•P,m M., R. CP,uz E., CJ Poyser,Berkhamsted, U.K. FLATTEN,AND S. FUNESA. In press b. Ornate Hawk- SCHULZE, M.D. AND D.E WHITACRE. 1999. A classification Eagle (5}Oizaetusornatus). In D. Whitacre (ED.), Rap- and ordination of the tree community of Tikal Na- tors of the maya forest:ecology of a neDtropicalraptor tional Park, PetOn, Guatemala. Bull. Fla. Mus. Nat. community. Cornell University Press, Ithaca, NY Hist. 41:169-297. U.S.A. STARCK,J.M. ANDR.E. RICKLEFS.1998. Avian growth and , J. LOPEZA., G. LOPEZAviLA, S. FUNESAVltA, C J development: evolution within the altricial-precocial FLATrEN,AND J.A. M2mmDM. In pressc. Black Hawk- spectrum. Oxford UniversityPress, Oxfbrd, U.K. Eagle (Spizaetustyrannus). In D. Whitacre (ED.), Rap- WH1TACRE,D. F., J. LOPEZAVIL& AND G. LOPEZAVIL& In tors of the mayaforest: ecology of a neDtropicalraptor press a. Crested Eagle (Morphnusguianensis). In D.F. community. Cornell University Press, Ithaca, NY Whitacre (ED.), Raptors of the maya forest: ecology U.S.A. of a neDtropical raptor community. Cornell University Press, Ithaca, NY U.S.A. Received 2 December 2000; accepted 30 October 2001

j. RaptorRes. 36(1):81-84 ¸ 2002 The Raptor ResearchFoundation, Inc.

SPRINGWEATHER AND BREEDINGSUCCESS OF THE EURASIANKESTREL (FALCOTINNUNCULUS) IN URBAN ROME, ITALY

LUCA SALVATI 1 PiazzaE Morosini 12, 1-00136 Rome,Italy

KEYWORDS: Eurasian Kestrel;Falco tinnunculus; breeding lands (mainly dry pasturesand cereal crops), and small success;weather conditions; urban habitats; Mediterranean ar- oak woods (mainly Quercusilex). The two census plots eas. included one strictlyurban area (inner city) and one sub- urban, built-up area (Appia Antica park). Breeding den- sitywas 1.9 pairs/km2 (N = 86 pairs) in the urban area The breeding biology of the EurasianKestrel (Falcotin- and 0.6 pairs/km2 (N = 34 pairs) in the suburbanarea nunculus) has been well-studied in northern and central (Salvati et al. 1999). For census procedure to locate Europe mainly focusingon the influence of prey fluctu- breeding pairs see Salvati et al. (1999, 2000). ations on clutch size and productivity (e.g., Village 1990, Nests were monitored weekly from the pre-incubauon Plesnik and Dusik 1994, Valkama et al. 1995) as well as period. Visits were increased to 2-3 d intervals dunng on the influence of weather conditions on timing of the nesting period. Laying date for each nest was deter- breeding (Kostrzewaand Kostrzewa1990, 1991). In Med- nilned by subtractingthe mean incubation period of the iterranean Europe, few studies addressedthese aspects species(28 d; Avildset al. 2000) from the hatching date (Gil-Delgado et al. 1995) and relevant accountson kes- Hatching date was determined taking into account that all eggshatch in 4 d (Avildset al. 2000). Fledging date trel breeding successare by Rizzo et al. (1993), Gil-Del- was defined as the first day when all fledglings leave the gado et al. (1995), Fargallo et al. (1996), and Avilas et nest. Young generally stayfor 5-10 d in the vicinity of the al. (2000). Here, I provide data on the breeding success nest using perchespreviously frequented by the parents, of kestrelsin two different habitatsof Rome, central Italy, but rarely come back to the nest during daylight (Komen through 5 yr. I studiedbetween-year differences in breed- and Myer 1989, Bustamante1994). As the interval of nest •ng successin relation to spring weather and I compare visitswas 2-3 d, an error of __1 d should be assignedto my resultswith data collected 15 yr earlier from the same fiedging date. Glutch size and laying date were recorded population (Sommani 1986). for a subsampleof breeding pairs, becausemany nests were inaccessiblefor an exact count of eggs or chicks STUDY AREA AND METHODS during the early stagesof breeding (Salvati et al. 1999). I conducted fieldwork from March 1996-July 2000 in I measured percent egg productivity as the number of Rome, Latium, central Italy (41ø53'N, 12ø28'E).The area fledglings in a nest divided by the total number of eggs Nscharacterized by developed areas, urban parks, open- laid in that nest.Breeding parameters for the years1979- 85 were obtained through the sametechnique from Som- mani (1986). 1E-mail address:[email protected] As weather variables,I used mean monthly rainfall and