J. Field Ornithol., 62(3):403-406

DESCRIPTION OF THE COURTSHIP AND COPULATION BEHAVIOR OF THE CRANE-HAWK

HENRI OUELLET Canadian Museum of Nature P.O. Box $dd$, Statior• "D" Ottawa, Ontario KIP 6Pd, Canada Abstract.--This paperprovides the first descriptionof the courtshipbehavior and copulation of a pair of Crane-Hawks (Geranospizacaerulescens) as recordedin northeasternVenezuela. Copulationis describedas is the brief aerial displayand courtshipfeeding that precededit. Courtshipfeeding is elementaryand consistsof the male placingfood near the female. DESCRIPCI(•NDEL PATRONDE CORTEJOY C•)PULAEN GERANOSPIZA CAERULESCENS Sinopsis.--Estetrabajo proveede la primera descripci6ndel patr6n de cortejoy c6pulaen Geranospizacaerulescens, observado en el norestede .Se describela copulaci0n comotambi•n el brevevuelo de desplieguey alimentaci0nde cortejoque precedea •sta. La alimentaci6nde cortejoes elemental y consistedel machocolocar comida cerca de la hembra. The literature containssparse information on the reproductivebehavior and nestingof the Crane-Hawk (Geranospizacaerulescens) (Friedmann and Smith 1950, Mader 1981), a mediumsize long-legged hawk, which rangesfrom northern to easternBolivia and northern (Blake 1977, Brown and Amadon 1968, Haverschmidt1968, Meyer de $chauenseeand Phelps 1978, Wetmore 1965). Even lessis known about its courtship.From 19 to 22 Mar. 1988, I had the opportunityto observe someaspects of the courtshipbehavior and copulationof a pair of Crane- Hawks, approximately6 km southwestof E1 Furrial, Stateof Monagas, Venezuela. The purpose of this contribution is to describefor the first time aspectsof the reproductivebehavior of this .

OBSERVATIONS On 19 Mar. 1988, between0635 and 0650, I continuouslyobserved a pair of Crane-Hawks at the edgeof a mixed palm savannanear dense vegetationbordering a small stream and a shallow pond. A number of tall trees, 25-30 m high, dominatedthe surroundingbushy vegetation, which did not exceed6-8 m high. The vegetationtype of the region is typical of the "Savannagrasslands of the shield" (Cole 1986:93) and is characterizedby open camposcerrados-savanna woodlands with a few treesand a more extensivetree growthalong streams and low wet areas. A number of palm trees occupythe wetter open areas and the generalsector has been usedextensively for agriculturalpurposes with seasonalburning and ploughing. The first was seensitting in one of the tall trees on a leafless lateral branchsome 25 m from the ground.After flying off, it turned aroundand cameback to the otherside of the treewhere a second,slightly

403 404] H. Ouellet J.Field Ornithol. Summer 1991 larger bird, was sitting. I assumethe first bird was a male becauseof its obviouslysmaller size, and that the secondbird was a female. Before perching near the female, the male flew around the tree three times, flapping his wings slowly and partly gliding as he approachedthe perch. The male then landed near the female where he sat for nearly 30 s, after which she flew away climbing beyondthe top of the tallest trees. She then glided rapidly towardsthe mist netsthat had been setbelow the tree 2 d earlier at the edgeof shrubbyvegetation. The female circled them three times and returned to the same perch, near the male. The male then flew away from the perchdirectly into the empty netswhere he was caught.Gender was confirmedthrough the bird's greatly enlargedcloacal protuberance.When released,the male flew in circlesover the nets four or fivetimes and landednear the female.During this periodof observation, the male was callingfrequently, and a varietyof calls(described in Brown and Amadon [1968:376] and Friedmann and Smith [1950:449]) were heard at different intervals.The female also called,but lessfrequently, although I had the impressionthat both were at times calling alternativelyor in sequence.In someinstances, it seemedthat the female was respondingto the male. After having preenedhis feathers,the male flew away nearly a minute later and was followedby the female within a few seconds.Both birds disappearedin the distanceand were not seen again in the area until my departurearound 0930. On 20 March, mist nets were deployedbefore sunrisearound 0530 and no Crane-Hawk was noticed in the vicinity. Later, at 0610, as I cameback to the area to checkthe nets, I saw the male flying in circles some8 m abovethe female perchedon a branch some 10 m abovethe ground in the same tree that she had used on the previous morning. Suddenly,the male swungaround, made a broadcircle, and flew towards a Blue-black Grassquit (Volatiniajacarirta) trapped in one of the nets. He swoopedtoward it, hoveredvery closeto the net, and tried to remove the bird with his bill. The net was violentlyshaken. He then flappedhis wings stronglyand gained altitude well abovethe tops of the trees. He appearedto be unsuccessfulin removingthe grassquit,which remained motionlessin the net. The male then glided towards the female holding somethingin the bill and perched next to her. He appeared to deposit an object closeto her feet. Some 20 s later, without any warning, the male flew off about 1 m above the female and dropped onto her back, grasping on to her with his feet in the middle of the dorsum. She im- mediatelyopened her tail and orientedit in a perpendicularposition some 45ø from the horizontal so that her cloacabecame exposed sideways. In themeantime, the male maintained his equilibrium on her backby beating the wings slowly and graspingwith the bill the feathersof her occiput. He then openedhis tail asthe femalehad done,oriented it perpendicularly (45ø ) but in the other direction,and shiftedthe lower part of his bodyso that his cloaca would meet the female's. Contact lasted about 10 s, after which the male flew away and perchedat the top of a tall tree some200 m distant.The female continuedto sit at the sameplace and watchedthe Vol.62, No. 3 Crane-HawkCourtship and Copulation [405 nets. Ten minutes later, although the female was still on her perch, I inspectedthe nets to releasethe grassquit.The bird had been killed and its head had been removed neatly at the base of the cervical vertebrae. What the male had been carrying in the bill and what he had deposited near the female's feet was the head and skin of the neck of a male Blue- blackGrassquit. A few minuteslater, the female,oblivious to my presence (the nets being locatedless than 30 m from her perch) flew away and landed at the top of a distanttree. None of the birds were seenbefore I departed at around 0645. No nest was found in the area. Two birds were seenagain in the same area on 21 and 22 March and they were either perchedor foraging, but no calls were heard, nor were additional breedingdisplays observed.

DISCUSSION Several points emerge from these observations.First, my observations describingthe courtshipdisplay a pair of Crane-Hawk differ significantly from those reported by Brown and Amadon (1968:378). The precopu- lation displaythat I have describedis relatively simpleand doesnot consist of aerial flapping and soaringor other demonstrations(Brown and Ama- don 1968, Mader 1981). Second,the courtshipdisplay I observedincluded courtshipfeeding followed by a brief seriesof calls and copulation,as is known for severalother speciesof raptors. Indeed, what I saw is very similar to that describedby Smeenk and Smeenk-Enserink(1983:135) for the Hawk (Polyboroidestypus) although the two speciesare not closelyrelated. Finally, the time of the year when the display and copulationtook place coincideswith the breeding datesof this speciesas reported previously in Venezuela and adjacent areas (Friedmann and Smith 1950, Haverschmidt 1968, Mader 1981). ACKNOWLEDGMENTS

I take specialpleasure to thank Gedio Marin Espinozaand acknowledgehis assistance in the field in the courseof my work in Venezuela in 1988. I am also grateful to Jos• Ram6n RodriguezS. and RaymondMcNeil for facilitatingmy work in Venezuela,and to Keith L. Bildstein for his careful review of the manuscriptand his useful suggestions.

LITERATURE CITED

BLAKE,E.R. 1977. Manual of Neotropicalbirds. Volume 1. Univ. ChicagoPress, Chicago, Illinois. 674 pp. BROWN,L., AND O. AMADON. 1968. Eagles,hawks and falconsof the world. Volume 1. Country Life Books,Feltham, United Kingdom. 414 pp. COLE,M.M. 1986. The savannas.Biogeography and geobotany.Academic Press, New York, New York. 438 pp. FRIEDMANN,H., AND F. O. SMITH, JR. 1950. A contributionto the ornithologyof northeastern Venezuela. Proc. U.S. Nat. Mus. 100:411-538. HAVERSCHMIDT,F. 1968. Birds of Surinam. Oliver & Boyd, Edinburgh,United Kingdom. 445 pp. MADEI•, W.J. 1981. Notes on the nestingraptors in the llanosof Venezuela. Condor 83: 48-51. MEYER DE SCHAUENSEE,R., ANDW. H. PHELPS. 1978. A guide to the birds of Venezuela. PrincetonUniv. Press,Princeton, New Jersey. 424 pp. 406] H. Ouellet J.Field Ornithol. Summer 1991

SMEENK,C., ANDN. SMEENK-ENSERINK.1983. Observationson the Harrier Hawk Polybo- roidestypus in Nigeria, with comparativenotes on the Neotropical Crane Hawk Ger- anospizacaerulescens. Ardea 71:133-143. WETMORE,A. 1965. The birds of the Republic of . Part 1. SmithsonianMisc. Collect. 150:1-483. Received20 Aug. 1990; accepted14 Jan. 1991.

NORTH AMERICAN BLUEBIRD SOCIETY RESEARCH GRANTS--1992

The North American Bluebird Societyannounces the ninth annual grants in aid for orni- thologicalresearch directed toward cavity nestingspecies of North America with emphasis on the genusSialia. Presentlythree grants of single or multiple awards are awarded and include:

Bluebird Research Grant Available to student,professional or individual researcherfor a suitable researchproject focusedon any of the three speciesof bluebird for the genusSialia.

General Research Grant Available to student, professionalor individual researcherfor a suitable researchproject focusedon a North American cavity nestingspecies.

Student Research Grant Available to full-time collegeor universitystudents for a suitable researchproject focused on a North American cavity nestingspecies.

Further guidelinesand application materials are available upon request from:

Kevin L. Berner Research Committee Chairman Collegeof Agriculture and Technology State University of New York Cobleskill, New York 12043

Completedapplications must be receivedby December2, 1991; decisionswill be announced by January 15, 1992.