Falco Berigora)In the Canberra Region, Australia, with Comparisons to Other Regions

J. Raptor Res. 46(4):394–400 E 2012 The Raptor Research Foundation, Inc.

THE DIET OF BREEDING BROWN FALCONS (FALCO BERIGORA)IN THE CANBERRA REGION, AUSTRALIA, WITH COMPARISONS TO OTHER REGIONS

PAUL G. MCDONALD1 Behavioural and Physiological Ecology Research Centre, Zoology, University of New England, Armidale, NSW 2351, Australia

JERRY OLSEN Institute for Applied Ecology, University of Canberra, ACT 2601, Australia

A.B. ROSE2 Australian Museum, 6 College Street, Sydney, NSW 2010 Australia

ABSTRACT.—Brown Falcons (Falco berigora) are generalist predators that take prey from a range of different taxonomic groups. Further, this species is one of the most widespread raptors in Australasia, providing great scope for dietary flexibility. However, few studies have reported on the diet of this species, and none in any detail for the relatively dry, continental climate of the Canberra region of southeastern Australia. We therefore examined this species’ diet from 29 collections of prey remains and pellets from 20 nesting territories over five breeding seasons of Brown Falcon pairs breeding within 40 km of Canberra in 2002– 06 and again in 2009. A total of 307 prey items was recorded, 15 of which were novel for this species. These novel prey items largely reflected locally common species that were of a similar size and niche to prey previously recorded in other regions, such as a new prey species of quail or beetle. Unusual prey included garden snails (Helix aspersa) and an owl, the Southern Boobook (Ninox novaeseelandiae). Other infrequently captured prey items such as freshwater molluscs (Corbicula australis and Glyptophysa gibbosa) and crayfish (Cherax sp.) illustrated the extraordinary dietary flexibility of Brown Falcons. In comparison with previous detailed studies, Canberra-based pairs had a relatively small geometric mean prey weight of 7.7 g, and tended to take a higher proportion of invertebrates across a relatively narrow niche breadth. When biomass was considered, rabbits (Oryctolagus cuniculus) were an important food source, making up half of the total biomass in the diet.

KEY WORDS: Brown Falcon; Falco berigora; diet; nest; prey; rabbit; rabbit calicivirus disease.

DIETA DE INDIVIDUOS REPRODUCTIVOS DE FALCO BERIGORA EN LA REGIO´ N DE CANBERRA, AUSTRALIA Y COMPARACIONES CON OTRAS REGIONES

RESUMEN.—Falco berigora es un depredador generalista que obtiene sus presas de una amplia variedad de grupos taxono´micos. Adema´s, esta especie es una de las rapaces de mayor distribucioń en Australasia, lo que le genera grandes oportunidades para una dieta flexible. Sin embargo, se han reportado pocos estudios sobre la dieta de esta especie y ninguno para el clima seco y continental de la regioń de Canberra en el sureste de Australia. Es por ello que examinamos la dieta de esta especie en 29 colecciones de restos de presa y heces de 20 territorios de nidificacioń en cinco estaciones reproductivas de parejas de F. berigora anidando dentro de los 40 km de Canberra en 2002–06 y nuevamente en 2009. Se registro´ un total de 307 piezas de presa, 15 de las cuales fueron novedosas para esta especie. Estas piezas de presa nuevas reflejan en gran medida especies localmente comunes que presentaron un tamanõ y un nicho de presa similares a los registrados previamente en otras regiones, tales como una nueva especie de presa de codorniz o escarabajo. Las presas inusuales incluyeron un caracol de jardıń (Helix aspersa) y un bu´ho(Ninox novaeseelandiae). Otras presas capturadas con poca frecuencia como moluscos de agua dulce (Corbicula australis y Glyptophysa gibbosa) y cangrejos de rıó (Cherax sp.) ilustran la extraordinaria flexibilidad de la dieta de F. berigora. En

1 Email address: [email protected] 2 Current address: 61 Boundary Street, Forster, NSW 2428 Australia

394 DECEMBER 2012 BROWN FALCON DIET AT CANBERRA 395

comparacioń con estudios detallados previos, las parejas establecidas en Canberra presentaron una media geome´trica de peso de presa relativamente pequenã de 7,7 g y tendieron a cazar una mayor proporcioń de invertebrados en un ancho de nicho relativamente angosto. Cuando se considero´ la biomasa, los conejos (Oryctolagus cuniculus) fueron una fuente importante de alimento, abarcando la mitad de la biomasa total de la dieta. [Traduccioń del equipo editorial]

The Brown Falcon (Falco berigora) is one of Aus- the Canberra region during five breeding seasons tralia’s most frequently encountered birds, being (November to February) 2002–03 to 2005–06 and found in almost every habitat throughout the con- for the 2009–10 season. tinent (Marchant and Higgins 1993, Barrett et al. 2003). The species’ broad habitat requirements METHODS are matched by its dietary preferences. Whereas Study Area. We sampled 20 separate territories of the rest of Australia’s falcons have comparatively Brown Falcons within 40 km of the center of Can- narrow dietary preferences, Brown Falcons (mean berra, Australia (35u16.929S, 149u7.729E). Details of weight: male 506 g, female 681 g; Marchant and the study area have been published elsewhere (Ol- Higgins 1993) frequently take prey from a very large sen et al. 2008). Briefly, Brown Falcon nests in the range of taxa that includes small mammals, passer- region were all located in open, dry forest with ad- ines, waterbirds and gulls, lizards and skinks, snakes, jacent grassy valleys that is typical of the preferred amphibians, and invertebrates such as spiders, bee- woodland habitat of this species. tles, and freshwater molluscs (Baker-Gabb 1984a, Collection and Analysis of Prey Material. Evi- 1984b, Marchant and Higgins 1993, Aumann 2001, dence of breeding-season diets was gathered by McDonald et al. 2003, McDonald and Baker-Gabb collecting regurgitated pellets and prey remains 2006). Although this dietary flexibility at the popu- within or near (,5 m) nest sites annually. Collec- lation level is a likely factor behind this falcon’s tion occurred either during the nestling stage or widespread distribution, individual pairs of Brown post-fledging, from November to February. Data Falcons sometimes concentrate heavily on particu- collated from analysis of pellets and nest remains lar prey types, such as rabbits or reptiles (McDonald were combined and assessed together, to avoid bi- et al. 2003; see Table 1 for specific names). This asing results from using a sole technique (Collopy pattern likely results from individuals taking advan- 1983). To identify prey species, material was com- tage of local, small-scale changes in prey abun- pared with representative samples using a combina- dance, as prey preferences overlap by 84% for dif- tion of private collections and specimens from the ferent individuals occupying the same territory 20 yr Australian Museum, Sydney. The number of prey apart (McDonald and Baker-Gabb 2006). items in each sample was estimated using the min- Despite the Brown Falcon’s almost ubiquitous imum number of individuals (MNI) technique out- presence and ready accessibility to researchers, to lined by Olsen et al. (2008). Mean prey weights date publications on its dietary preferences have were taken from the literature (Table 1) and used largely been confined to the southeast of the Aus- to calculate geometric mean prey weight (GMPW; tralian mainland, in either southern or northern Marti et al. 1993). Using this figure, rather than an Victoria (Baker-Gabb 1984a, 1984b, McDonald et overall mean prey weight, avoids potential biases al. 2003, McDonald and Baker-Gabb 2006), with ad- related to the typically nonnormal distribution of ditional studies in arid, central Australia (Aumann prey weights in raptor diets. Items were identified 2001) and extensive but unpublished dietary rec- to the species level where possible, or to a mini- ords from Tasmania (Mooney in Marchant and Hig- mum of genus (vertebrates) or order (inverte- gins 2003). Although Canberra has a rich history of brates). Finally, to provide an indication of diet raptor research (Olsen et al. 2006a, 2006b, 2008, breadth that was comparable across previous stud- 2010, Fuentes et al. 2007, Trost et al. 2008), as yet ies for this species in other regions, we examined no study has examined the dietary breadth of Brown the proportion of prey taken from one of four Falcons occupying this woodland-grassland region groups: mammals, birds, reptiles/amphibians, and in detail (see Bollen 1993 for a sample from one invertebrates. These proportions were converted pair). We sought to rectify this lacuna by examining into a standardized niche width index according the diet of breeding Brown Falcons in and around to Marti et al. (1993), where: 396 MCDONALD ET AL.VOL. 46, NO.4

Table 1. Prey type and biomass for 307 prey items collected from 20 Brown Falcon territories during the breeding seasons of 2002–09. Note that two small samples of plant material were found, but were assumed to be from the gut of prey items and not included here. Biomasses taken from Baker et al. (1997), McDonald et al. (2003), Olsen et al. (2006b), or Strahan (1995) for consistency with previous dietary studies. Mollusc biomass estimated.

NO. OF %TOTAL TOTAL COMMON NAME SCIENTIFIC NAME ITEMS ITEMS BIOMASS (g) % BIOMASS MAMMALS Antechinus undetermined Antechinus sp. 2 0.7 40 0.1 Common dunnart* Sminthopsis murina 1 0.3 17 0.04 Ringtail possum Pseudocheirus peregrinus 1 0.3 700 1.5 Eastern grey kangaroo*1 Macropus giganteus 2 0.7 200 0.4 Eastern grey kangaroo juv.*1 1 0.3 100 0.2 Swamp wallaby*1 Wallabia bicolor 2 0.7 200 0.4 House mouse Mus musculus 11 3.6 187 0.4 Black rat Rattus rattus 1 0.3 280 0.6 European rabbit Oryctolagus cuniculus 12 3.9 18 000 37.9 European rabbit juv. 12 3.9 6000 12.6 Brown hare Lepus capensis 3 1.0 12 000 25.3 Sheep1 Ovis aries 3 1.0 300 0.6 TOTAL MAMMALS 51 16.6 38 024 80.1 BIRDS Painted Buttonquail* Turnix varia 1 0.3 60 0.1 Australian Wood Duck* Chenonetta jubata 2 0.7 1600 3.4 Galah Cacatua roseicapilla 2 0.7 670 1.4 Crimson Rosella* Platycercus elegans 2 0.7 260 0.5 Crimson Rosella juv.* 1 0.3 119 0.3 Eastern Rosella* Platycercus eximius 7 2.3 735 1.5 Rosella undet. Platycercus sp. 2 0.7 224 0.5 Red-rumped parrot Psephotus haematonotus 4 1.3 244 0.5 Parrot undet. Order Psittaciformes 1 0.3 61 0.1 Southern Boobook – juv.* Ninox novaeseelandiae 1 0.3 250 0.5 Hooded Robin* Melanodryas cucullata 1 0.3 19 0.04 Australian Magpie Gymnorhina tibicen 4 1.3 1268 2.7 European Starling Sturnus vulgaris 6 2.0 468 1.0 European Starling juv. 1 0.3 75 0.2 Small passerine undet. 1 0.3 40 0.1 Other birds undet. 8 2.6 320 0.7 TOTAL BIRDS 44 14.3 6413 13.5 REPTILES Jacky lizard Amphibolurus muricatus 4 1.3 120 0.3 Eastern water dragon Physignathus lesueurii 1 0.3 500 1.1 Dragon undet. Family Agamidae 1 0.3 300 0.6 Striped skink Ctenotus robustus 2 0.7 60 0.1 Skink undet. Family Scincidae 11 3.6 330 0.7 Eastern brown snake Pseudonaja textilis 2 0.7 600 1.3 Red-bellied black snake Pseudechis porphyriacus 1 0.3 300 0.6 TOTAL REPTILES 22 7.2 2210 4.7 MOLLUSCS Little basket shell Corbicula australis 14 4.6 70 0.1 Garden snail* Helix aspersa 4 1.3 24 0.1 Water snail Glyptophysa gibbosa 1 0.3 5 0.01 TOTAL MOLLUSCS 19 6.2 99 0.2 DECEMBER 2012 BROWN FALCON DIET AT CANBERRA 397

Table 1. Continued.

NO. OF %TOTAL TOTAL COMMON NAME SCIENTIFIC NAME ITEMS ITEMS BIOMASS (g) % BIOMASS

CRUSTACEANS Crayfish Cherax sp. 2 0.7 400 0.8 TOTAL CRUSTACEANS 2 0.7 400 0.8 INSECTS Christmas beetle Anoplognathus porosus 26 8.5 52 0.1 Christmas beetle A. viriditarsus 3 1.0 6 0.01 Christmas beetles undet. Anoplognathus sp. 29 9.4 58 0.1 Cerambycid beetle* Family Cerambycidae 1 0.3 2 0.004 Weevil Family Curculionidae 6 2.0 12 0.03 Black beetle* Heteronychus arator 17 5.5 34 0.1 Stag beetle* Lamprima latreille 2 0.7 4 0.01 Scarab beetle undet. Family Scarabaeidae 7 2.3 14 0.03 Dung beetle* Onthophagus australis 6 2.0 12 0.03 Passalid beetle* Family Passalidae 1 0.3 2 0.004 Repsimus beetle* Repsimus aeneus 1 0.3 2 0.004 Tenebrionid beetle* Family Tenebrionidae 1 0.3 2 0.004 Beetle undet. Order Coleoptera 16 5.2 32 0.1 Cicada Psaltoda moerens 36 11.7 72 0.2 Cockroach undet. Blattoidea 2 0.7 4 0.01 Grasshoppers Family Acrididae 15 4.9 30 0.1 TOTAL INVERTEBRATES 169 55.0 338 0.7 GRAND TOTAL 307 100.0 47 484 100.0

1 Indicates a prey item likely taken as carrion, with biomass contribution estimated at 100 g. * Indicates a novel, previously unrecorded prey item for this species.

~ 2 6 6 B 1 Spi ðiÞ (mean 4.5 5.6 [SD] pellets and 3.4 5.6 remains per collection). In all, 51 different types of prey were detected; 15 of these had not previously been and pi indicates the proportion of prey group 1, with calculations made for all prey groups. This recorded as Brown Falcon prey (Table 1). Some must have clearly been taken as carrion, such as index was standardized by applying the formula: the large macropods that could not possibly have been killed by this species (Table 1). Nonetheless, BSTA~ðÞBOBS{BMIN =ðÞðBMAX{BMIN iiÞ novel items likely to have been captured before consumption included garden snails, several passerine species, small marsupials, and freshwater BOBS here is equal to B in formula i above, and was calculated for both data presented herein and also molluscs. Overall mean geometric prey weight was 9.9 g and other significant studies undertaken on Brown Fal- dietary breadth B 5 0.43 (based upon the four cons throughout their range to date. B and STA MIN food groups of mammals, birds, amphibians/rep- BMAX indicate the minimum and maximum values tiles, and invertebrates). This was the lowest mean for B possible (1 and 4, respectively; Marti et al. prey weight, and the second lowest niche breadth, 1993). recorded to date for this species (Table 2). In comparison to previous studies that were conducted RESULTS with similar methodologies in other locations, birds We found 307 prey items in the 125 pellets and 96 in the Canberra region took a high proportion of prey remains collected. This material originated invertebrate and a low proportion of vertebrate from 29 collections from 20 separate nesting areas prey, particularly mammal and avian prey items. 398 MCDONALD ET AL.VOL. 46, NO.4

Table 2. The abundance (percentage) of different prey groups in the diet of Brown Falcons in different areas of their range. Standardized dietary breadth indices (BSTA) and geometric mean prey weights (GMPW) are also provided (see methods for details of calculation).

LOCATION

CANBERRA1 MELBOURNE2 MELBOURNE3 MILDURA4 TASMANIA5 ALICE SPRINGS6 PREY GROUP (n 5 307) (n 5 740) (n 5 353) (n 5 246) (n 5 1229) (n 5 734) Mammals 16.6 48.6 46.4 48.7 5.6 3.7 Birds 14.3 35.5 29.8 34.5 8.2 14.4 Amphibians/Reptiles 7.2 12.4 13.1 3.6 10.3 27 Invertebrates 61.9 3.6 10.6 8.9 76.4 54.9 BSTA 0.43 0.55 0.67 0.58 0.22 0.51 GMPW (g) 9.9 77.03 - 29–42 14 38.5

1 this study. 2 McDonald et al. 2003. 3 Baker-Gabb 1984a. 4 Baker-Gabb 1984b. 5 Mooney in Marchant and Higgins 1993. 6 Aumann 2001.

DISCUSSION common in previous studies (Baker-Gabb 1984a, This study provides the first in-depth report of the 1984b, Marchant and Higgins 1993, Aumann 2001, diet of Brown Falcons breeding in the Canberra McDonald et al. 2003, McDonald and Baker-Gabb region. In comparison with other, previously sur- 2006). Macropods provide a rarely noted source of veyed populations, Canberra-based pairs had a low- carrion, with macropod remains featuring in only er vertebrate and a higher invertebrate component one other study to date (Aumann 2001), although to their diet, with this focus leading to a relatively it is not unusual for Brown Falcons to take carrion narrow niche width and smaller mean prey size. (Marchant and Higgins 1993). This was similar to dietary data reported in the only On the other hand, freshwater molluscs have other study in the region (Bollen 1993), which in- been recorded previously in the Brown Falcon’s dicated that the single pair observed took 49% diet only anecdotally (Marchant and Higgins invertebrate prey by number. This reliance upon 1993), and moreover represent an extremely un- invertebrates is interesting, as previous research on usual prey item for a falcon. This finding only this species has shown that diet composition plays a served to underscore the flexibility of Brown Fal- critical role in biomass available to nestlings, repro- cons in exploiting the availability of a wide range of ductive output, and thus the fitness of populations prey species. A Southern Boobook also represented (McDonald et al. 2004, 2005). The fact that these an unusual prey item, and may well reflect either Canberra pairs took relatively small prey items sug- fatal interspecific aggression, as is thought for other gests that they may also have lower-than-average re- raptors in the diet of Brown Falcons, such as Elanus productive success, at least in terms of the probabil- kites (McDonald et al. 2003), or a juvenile owl that was ity of clutch initiation in a given year (McDonald flushed or exposed during daylight. Also unusual was et al. 2004). We currently have too little data to test the consumption of a garden snail (Helix aspersa), a this hypothesis directly. species not typically considered prey of raptors, with The size, species, and broad categories of prey the exception of specialist species such as the Snail Kite taken largely reflected those reported in previous (Rostrhamus sociabilis; Beissinger 1990). Finally, partic- studies of Brown Falcon diet. Thus, many prey items ularly given that at least some pairs were hunting near that have not previously been recorded likely reflect freshwater, there was a surprising paucity of amphibi- local availability or scarcity. Numerous inverte- ans in the diet recorded from the Canberra region. brates, and the Hooded Robin (Melanodryas cucul- Previous studies have generally reported one or two lata) and Painted Buttonquail (Turnix varia) are species of frogs in the diet, although they have always likely examples of this phenomenon, as passerines, provided a modest contribution to total biomass quail, and invertebrates, particularly beetles, are (Marchant and Higgins 1993, McDonald et al. 2003). DECEMBER 2012 BROWN FALCON DIET AT CANBERRA 399

A heavy reliance on introduced lagomorphs (Le- ACKNOWLEDGMENTS pus and in particular Oryctolagus sp.) by breeding Thanks to Esteban Fuentes, Sue Trost, and Mark Os- pairs of Brown Falcons is typical for several areas good for assistance in collecting prey. We are also grateful (Baker-Gabb 1984a, 1984b, Marchant and Higgins for advice received from Jeff Jolly, Nick Mooney, Joan Real, 1993, Aumann 2001, McDonald et al. 2003, McDon- Luis Palma, Christie Gould, Michael Maconachie, Nick Webb, Geoffrey Dabb, Michael Lenz, Les Boyd, and the ald and Baker-Gabb 2006). The proportion of rab- ACT Parks and Conservation Service, including David bits documented in this study was relatively low at Shorthouse, Murray Evans, Bernard Morris, Brett Macna- 7.8% of prey items, a minor amount in comparison mara, Don Fletcher, and Darren Rosso. Particular thanks to northwestern Victoria where rabbits constituted to Walter Boles, John Disney, Ian Lock, and Michael Shea as much as 46.3% of the diet (Baker-Gabb 1984b). of the Australian Museum for aid with the identification of some specimens, and Sean Doody from the Institute for Whether this difference reflected individual dietary Applied Ecology and Robert Palmer from the Australian preferences or prey availability, perhaps related to National Wildlife Collection for mass estimates of some reductions in rabbit numbers following the intro- prey. Special thanks to Ross Bennett, Enzo Guarino, Ar- duction of rabbit calicivirus (e.g., Sharp et al. thur Georges, Gabriela Peniche, and the Kippax Veteri- nary Hospital for their assistance with prey masses. Three 2002), was unclear. At least for the twenty sites sam- referees provided helpful comments that improved the pled in this study, rabbit numbers seem to be more manuscript, for which we are grateful. The study method- governed by localized activities such as poisoning ology was approved by the University of Canberra Animal than calicivirus (J. Olsen unpubl. data), although Ethics Committee Registration Number CEAE 02/10. definitive data is difficult to gather. However, de- LITERATURE CITED spite the low numerical contribution of rabbits to the diet of the Brown Falcon population at Can- AUMANN, T. 2001. An intraspecific and interspecific com- berra, they still made up half of the total biomass parison of raptor diets in the south-west of the North- ern Territory, Australia. Wildlife Research 28:379–393. captured. Thus, introduced rabbits were one of the BAKER, G.B., E.B. DETTMANN, B.T. SCOTNEY, L.J. HARDY, AND more important food items for this population and D.A.D. DRYNAN. 1997. Report on the Australian Bird indeed this species across its range. and Bat Banding Scheme, 1995–96. Environment Aus- Finally, given their similar niche space, it is worth tralia, Canberra, Australia. considering how these dietary data compare to those BAKER-GABB, D.J. 1984a. The feeding ecology and behav- of another woodland generalist raptor breeding in iour of seven species of raptor overwintering in coastal the same region, the Brown Goshawk (Accipiter fascia- Victoria. Australian Wildlife Research 11:517–532. tus). Brown Goshawks are slightly smaller than Brown ———. 1984b. The breeding ecology of twelve species of Falcons, at ca. 350 g (males) and 580 g (females; diurnal raptor in north-western Victoria. Australian Marchant and Higgins 1993), but have a similarly Wildlife Research 11:145–160. broad diet (e.g., Aumann 2001). Goshawks in the BARRETT, G., A. SILCOCKS,S.BARRY,R.CUNNINGHAM, AND study region took a lower proportion of invertebrate R. POULTER. 2003. The new atlas of Australian birds. Shannon Books, Melbourne, Australia. prey than the Brown Falcons (22.7% vs. 55% by num- BEISSINGER, S.R. 1990. Experimental brood manipulations ber; Olsen et al. 2006b). Instead, for goshawks in the and the monoparental threshold in Snail Kites. Ameri- Canberra region, rabbits composed a much greater can Naturalist 136:20–38. percentage of the diet (18.2% by number and 66.3% BOLLEN,C.1993.Breedingbehaviouranddietofthe by mass) than found in the Brown Falcon nests sam- Brown Falcon Falco berigora on the southern tablelands pled herein (7.8% and 50.5%, respectively; Table 1). of New South Wales. Australian Bird Watcher 15:19–23. However, given that these Brown Goshawk data were COLLOPY, M.W. 1983. A comparison of direct observations collected during an earlier time period than the falcon and collections of prey remains in determining the diet data presented here (Olsen et al. 2006b), it remains of Golden Eagles. Journal of Wildlife Management unclear whether this difference might be due to tem- 47:360–368. poral displacement and corresponding differences FUENTES, E.J., J.E. OLSEN, AND A.B. ROSE. 2007. Diet, occu- pancy, and breeding performance of Wedge-tailed in rabbit availability, or rather reflects consistent dif- Eagles Aquila audax near Canberra, Australia 2002– ferences in the importance of rabbit during breeding 2003: four decades after Leopold and Wolf. Corella season to these ecologically similar species. Further 31:65–72. study examining the potentially complex niche over- MARCHANT,S.AND P.J. HIGGINS.[EDS.]. 1993. Handbook of lap between these two species, and indeed the precise Australian, New Zealand and Antarctic Birds. Vol. 2: relationship between rabbit abundance and raptor Raptors to lapwings. Oxford Univ. Press, Melbourne, breeding activity in general, remains warranted. Australia. 400 MCDONALD ET AL.VOL. 46, NO.4

MARTI, C.D., E. KORPIMA¨ KI, AND F.M. JAKSIC. 1993. Trophic ———, ———, AND A.B. ROSE. 2006a. Trophic relationships structure of raptor communities: a three-continent com- between neighbouring White-bellied Sea-Eagles Haliaeetus parison and synthesis. Current Ornithology 10:47–137. leucogaster and Wedge-tailed Eagles Aquila audax breeding MCDONALD, P.G. AND D.J. BAKER-GABB. 2006. The breeding on rivers and dams near Canberra. Emu 106:193–201. diet of different Brown Falcon (Falco berigora) pairs oc- ———, ———, ———, AND S. TROST.2006b.Foodand cupying the same territory over twenty years apart. Jour- hunting of eight breeding raptors near Canberra, 1990– nal of Raptor Research 40:228–231. 94. Australian Field Ornithology 23:77–95. ———, P.D. OLSEN, AND D.J. BAKER-GABB. 2003. Territory ———, D. JUDGE, E.J. FUENTES, A.B. ROSE, AND S. DEBUS. fidelity, reproductive success and prey choice in the 2010. Diets of Wedge-tailed Eagles (Aquila audax) and Brown Falcon Falco berigora: a flexible bet-hedger? Aus- Little Eagles (Hieraaetus morphnoides) breeding near Can- tralian Journal of Zoology 51:399–414. berra, Australia. Journal of Raptor Research 44:50–61. ———, ———, AND A. COCKBURN. 2004. Weather dictates SHARP, A., L. GIBSON,M.NORTON,B.RYAN,A.MARKS, AND reproductive success and survival in the Australian L. SEMERARO. 2002. The breeding-season diet of Wedge- Brown Falcon Falco berigora. Journal of Animal Ecology tailed Eagles (Aquila audax) in western New South 73:683–692. Wales and the influence of rabbit calicivirus disease. ———, ———, AND ———. 2005. Selection on body size Wildlife Research 29:175–184. in a raptor with pronounced reversed sexual size di- STRAHAN,R.[ED.]. 1995. The mammals of Australia, Sec- morphism: are bigger females better? Behavioral Ecology ond Ed. Reed Books, Chatswood, Australia. 16:48–56. TROST, S., J.E. OLSEN, A.B. ROSE, AND S. DEBUS. 2008. Win- OLSEN, J.E., E.J. FUENTES,D.M.BIRD,A.B.ROSE, AND D. ter diet of Southern Boobooks Ninox novaeseelandiae in JUDGE. 2008. Dietary shifts based on prey availability Canberra 1993–2004. Corella 32:66–70. in Peregrine Falcons and Australian Hobbies near Can- berra, Australia. Journal of Raptor Research 42:125–137. Received 18 January 2012; accepted 1 July 2012