J. RaptorRes. 32 (1) :64-73 ¸ 1998 The Raptor ResearchFoundation, Inc. STATUS AND CONSERVATION OF RAPTORS IN AUSTRALIA' S TROPI CS NICK MOONEY Parksand WildlifeSet'vice, GPO Box 44A, Hobart 7001, Tasmania,Australia ABSTRACT.----•Iof Australia's34 raptorsare found in the tropics.No full speciesand onlyone subspecies, an island endemic owl, are extinct. All of Australia'sthree threatened, diurnal speciesare endemic to the continent. One, the Vulnerable Red Goshawk (Erythrotriochisradiatus), is endemic to Australia's tropical forestsand is under threat from lossof habitat, persecution,and egg collecting.Conservation efforts include legal protection, education, and keeping nest sitessecret. A secondspecies, the rare Square-tailedKite (Lophoictiniaisura) is widelydistributed and, exceptfor clearingof woodland,threats are not obvious.Many raptors from arid areas,including the endemic Grey Falcon (Falcohypoleucos), "winter" in tropicalwoodlands. For adequateconservation, critical habitatsof the Grey Falconmust be identified. Grey Falconsshould be helped in the long term by the anticipatedreduction of rabbitsin arid Australiaby rabbit calicivirusdisease, but widespreadclearing of tropicalwoodlands for agriculture continuesas does local, heavy use of pesticides.Although no speciesof owls are threatened, five sub- speciesare; two are subspeciesof the endemic RufousOwl (Ninox rufa, one rare and one insufficiently known) and two are subspeciesof the Masked Owl (Tyt0 novaehollandiae,both insufficientlyknown). Threats include lossof critical habitat to fire and agriculture.On ChristmasIsland, the smallpopulations of endemicsubspecies of the BrownGoshawk (Accipiterfasciatus) and MoluccanHawk-owl (N. squamipila) are Vulnerable and threatened by loss of habitat to urbanization and formerly mining. Besideslegal protection, conservationefforts have included educationand habitat preservation.The tropicalEastern Grass-owl(T. longimembris)is secure although some populationsare under pressurefrom agriculture (including rodenticides) and urbanization. Coastal, tropical raptors appear secure even though per- manent reductions in some populations have been causedby agriculture, urbanization, and coastal developmentssuch as aquacultureand marinas. KEYWORDS: tropicalraptors; Australia; conservation; status. Estadoy conservaci6nde las avesrapaces en los tr6picosde Australia RESUMEN.--Todaslas 34 especiesde avesrapaces de Australiase encuentranen los tr6picos.Una de las tres especiesamenazadas de Australia,Erythrotriorchis radiatus es end6mico a los bosquestropicales de Australiay esfftamenazada por la p6rdida de habitat, persecuci6n,y saqueode huevos.Los esfuerzos de conservaci6nhan incluido su protecci6n legal, educaci6n, y protecci6n de nidos. Una segunda especieLophoictinia isura esfft ampliamente distribuida, excepto por la deforestaci6n,las demas amenazas no son obvias.Varias avesrapaces de regiones gridas incluyendo al endfmico Falcohypoleucos emigran hacia los bosquestropicales. Desde el punto de vista de la conservaci6n,los habitatscriticos de F. hypoleucosdeben de ser identificadosdebido a que la deforestaci6npara la agriculturacontinfia al igual que el uso intensivo de pesticidas.Aunque ningfin buho ha sido identificado como amenazado,en Australia,dos rarasy poco estudiadassubespecies del end6mico Ninox rufa y dos subespeciesde Tyto novaehollandiaeesfftn amenazadas en las /treastropicales. Las amenazasincluyen la p6rdida de habitats criticosdebido al filego y a la agricultura.En la Isla Christmas,las reducidaspoblaciones de Accipiter fasciatusy de N. squamipilaestrin amenazadas debido a la p6rdida de habitat por actividades•nineras y el desarrollo urbanistico.Aparte de la protecci6n legal, los esfuerzosde conservaci6nhan incluido educaci6ny protecci6n del habitat. Aunque aparentementeestables algunas poblaciones de 7: lon,•- memtm'sesfftn bajo presi6n debido a la agricultura (incluyendoel uso de rodenticidas)y el desarrollo urbano. Aunque las poblacionesde avesrapaces costeras esfftn estables, estas han tenido continuadas reduccionescausadas por la agricultura,la urbanizaci6n,y por desarrolloscosteros tales como proyectos de acuaculturay marinas. [Traducci6n de C6sarMarquez] 64 M_2mCH 1998 ST^TUS OF TROPICAL AUSTRALIAN RAPTORS 65 BACKGROUND Australia. Tropical areas also spread inland along Australia is a continent with an area totaling permanent rivers and wetlands and include some about 7.7 million km 2. It includes a few small is- areasof highlandssuch as the Atherton tablelands. lands, one of which is Christmas Island in the In- Adjacent islands off these areas including Christ- dian Ocean, approximately 1400 km northwest of mas Island are also wet and support rainforests. Australia near the Indonesian island of Java. Aus- The dry tropics are comprised of mainly savanna tralia is the driest continent and less than 15% is woodlands and a variety of permanent and tem- covered by tropical forests located on the north porary waterwaysand wetlands. They are located and northeastern coasts. Although people have south of the wet tropicsbut north of a line extend- slowly modified these forests using fire over at ing acrossthe continent from the mid-east to the mid-upper westcoast from about Brisbaneto about least 60 000 yr, it has only been in the last 200 yr Broome (Fig. 1). since Europeans arrived that this change has ac- celerated. While the size of the continent has shel- Raptorsare very mobile birds and most species are able to utilize a variety of habitats. Therefore, tered most raptors from threats to tropical forests, I was cautiouswhen assigningspecies to habitats small islands have not escaped these effects. The and used broad definitions. wet, tropical forestsof Australia showdistinct sea- sonality but have long-term ecological stability. USE OF AUSTRALIA'S TROPICS BY RAPTORS The occurrence of irregular, severe inland Presenceand Core Range. All 34 speciesof Aus- droughts make the continent's biogeography tralian raptors are found in the tropics. Of Austra- unique (Nix 1972, Flannery1994). This instability lia's 10 endemic raptor species, only two, the has resulted in many arid and semiarid birds, rap- monotypic Red Goshawk (Erythrotriorchisradiatus) tors included, becoming migrants during drought and LesserSooty-owl (Tyto multipunctata),are en- periods with many showing both inland-coastal demic to the tropicsas are four and eight subspe- and south-north movements (Baker-Gabb and cies of Falconiformes and Strigiformes, respective- Fitzherbert 1989). These local movements may be ly. One other monotypic species,the Square-tailed small in relation to the size of the continent but Kite (Lophoictiniaisura), six subspeciesof Falconi- they are still large in absoluteterms and their ap- formes, and six of Strigiformeshave large portions parent dispersive rather than routed nature of their ranges in the tropics (Blakers et al. 1984, makes their study difficult. Debus and Czechura 1988b, Marchant and Higgins Another unusual movement is the irruptive ten- 1993). Australia is relatively close to Melanesia and dency of a few raptor species.This type of move- some raptors interchange between the two includ- ment usuallyfollows heavy rains marked by increas- ing Swamp Harriers (Circusapproximans), Austra- es in rodent numbers, and rapid breeding in pop- lian Hobbies (Falcolongipennis), and Nankeen Kes- ulationsof Letter-wingedKites (Elanusscriptus) and trels (F. cenchroides).Numbers of raptors that inter- Black Kites (Milvus migrans)which then disperse change are not known but neither location is when dry conditions return and rodent numbers known to be a major wintering area for interchang- crash (Hollands 1977, Laveryand Johnson1993). ing species(Baker-Gabb and Fitzherbert 1989). This paper examines raptors in wet tropics (a Wet rs. Dry Tropics. More speciesof Strigifor- stronglyseasonal environment) and dry tropics (an mes rely on the wet tropics than do Falconiformes. environment stable in the short to medium term Seven species of Strigiformes are endemic while but unstable in the longer term). It is important only three speciesof Falconiformes are exclusively to make this distinction because tropical raptors found in the wet tropics.All told, 10 of Australia's may be largely dependent on a systemwith long- 19 speciesand subspeciesof Strigiformesbut only term stabilityand they may be slowto adapt to en- 10 of 28 speciesand subspeciesof Falconiformes vironmental changes. are either endemic to or a large segment of their The Australian wet tropics contain both open core ranges lies within the wet tropics. Conversely, and closedforests, including rainforeston the con- the dry tropics are more important to the majority tinent's northeast coast. Mainly coastal,these for- of Australia's tropical Falconiformes. Six species ests extend from nearly half-way down the east are endemic to the dry tropics while this area has coast and all the way to the northwest corner of no endemic owls. 66 MOONEY VOL. 32, NO. 1 MARCH 1998 STATUS OF TROPICAL AUSTRALIAN RAPTORS 67 Movements. In the Australian tropics, there are lower (coastward) catchments of the larger rivers 13 resident Falconiformes,10 regular "winter" mi- around the Gulf Region are particularly important grants, and one species,the Black-breastedBuz- since they support the greatestraptor diversityand zard (Hamirostra melanosternon),that moves to the share the greatest abundance (Fig. 1). Grassy tropics and other coastal areas in responseto ir- woodlandssupport mainly Brown Falcons,Swamp regular, inland