Black-shouldered Kite Elanus axillaris Scientific name definitions

A small, mostly white falcon-like kite with gray upperwings; long and rather broad, pointed wings; and a short, white square-tipped or slightly notched tail (length 33–37 cm, wingspan 82–94 cm, male mass 181–295 g, female mass 270–340 g). It has a relatively large rounded head, and shallow gull-like wingbeats. Measurements and descriptions are from Marchant and Higgins (1 Marchant, S., and P. J. Higgins, Editors (1993). Handbook of Australian, New Zealand and Antarctic Birds. Volume 2. Raptors to Lapwings. Oxford University Press, Melbourne, Australia. Close ), Ferguson-Lees and Christie (2 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ), Debus (3 Debus, S. (2019). Birds of Prey of Australia, A Field Guide. Third edition. CSIRO Publishing, Melbourne, VIC, Australia. Close ), and Seaton et al. (4 Seaton, R., M. Gilfedder, and S. Debus (2019). Australian Birds of Prey in Flight, A Photographic Guide. CSIRO Publishing, Melbourne, VIC, Australia. Close ). Plumage changes with age.

Adults are white on the head and underbody; light gray dorsally, with a black patch in front of each eye extending as a thin black eyebrow, and black inner forewings; and dark gray primaries on long, pointed wingtips exceeding the tail tip. The tail is white, washed pale gray on the central rectrices. The underwings are white, with a black carpal spot and dark gray primaries. The bill is black, the cere horn to yellow, the irides are red, and the feet bright yellow. The sexes are similar, although females are slightly (1%) larger and up to 15% heavier. Juveniles (<1 yr) are washed and streaked rusty brown on the head, back and breast, with pale feather fringes on the back and forewings, and initially a thin rusty subterminal band on the tail. The cere is horn, the feet cream to dull yellow, and the eyes initially gray-brown, changing to yellow-brown then orange-red through the first year. Adult plumage is the same throughout the year; juvenile plumage quickly wears and fades, and changes to adult body plumage within the first year.

Distinguished from other Australian raptors by a combination of size, plumage, bare parts, structure, and flight behavior. Black-shouldered Kite is most likely to be confused with Letter-winged Kite (Elanus scriptus), Gray Falcon (Falco hypoleucos), and Gray Goshawk (Accipiter novaehollandiae); juvenile Black-shouldered Kites can be confused with Nankeen Kestrel (Falco cenchroides).

Black-shouldered Kite is distinguished from other gray and white raptors by plumage, shape, proportions, bare parts and flight behavior. Distinguished from Letter-winged Kite (Elanus scriptus) by facial features (black eyebrow versus black ring encircling each eye); underwing pattern (dark primaries and black carpal spot, versus pale primaries and solid black line from body to carpal); rapid and shallow wingbeats (versus slower and deeper beats); and typically diurnal foraging (versus daytime communal roosting and nocturnal foraging). Gray Goshawk (Accipiter novaehollandiae) has short, broad, rounded wings, long tail, barred breast, wings and tail, and long legs. Gray Falcon (Falco hypoleucos) has bright orange-yellow bare parts, wispy malar stripe, and streaked and barred plumage. Both latter species lack the black “shoulders” and hovering habit. Nankeen Kestrel (Falco cenchroides) has extensively rusty upperparts, slender build, barred wings and tail, and long tail with prominent black subterminal band.

In flight, Black-shouldered Kite is distinguished by its hovering habit with body inclined, feet lowered and tail depressed, and upswept wings when gliding and soaring; it drops feet-first, with wings raised high, at prey. Gray Goshawk, Gray Falcon, and Nankeen Kestrel soar and glide on flatter wings; Gray Goshawk has very rounded wings. Nankeen Kestrel hovers with body horizontal, and dives with closed wings at prey.

The most common vocalizations of the Black-shouldered Kite (chicken-like whistles, and harsh rasping wheeze), sometimes accompanied by tail raising after alighting, distinguish it from confusion species, other than Letter-winged Kite, which has similar calls.

The Black-shouldered Kite has ten full-length primaries (numbered distally, pp1‒10), 13 secondaries (numbered proximally, ss1‒10, and including three tertials, numbered distally, tt1‒3), and 12 rectrices (numbered distally, rr1‒6, on each side of the tail); hawks in Accipitridae are diastataxic (see 5 Bostwick, K. S., and M. J. Brady (2002). Phylogenetic analysis of wing feather taxis in birds: macroevolutionary patterns of genetic drift? Auk 119(4):943–954. Close ), indicating that a secondary has been lost evolutionarily between what we now term s4 and s5. Wings are rounded, p7 being the longest primary; pp6‒8 are notched on the outer web (sometimes p6 and p5 slightly) and pp7‒10 are emarginated on the inner web (6 Marchant, S., and P. J. Higgins, eds. (1993). Handbook of Australian, New Zealand and Antarctic Birds. Vol. 2. Oxford University Press, Melbourne. Close ). Little to no geographic variation in plumage has been described (see Geographic Variation). The following is based on descriptions in Marchant and Higgins (6 Marchant, S., and P. J. Higgins, eds. (1993). Handbook of Australian, New Zealand and Antarctic Birds. Vol. 2. Oxford University Press, Melbourne. Close ), along with examination of Macaulay Library images; see Pyle (7 Pyle, P. (2008). Identification Guide to North American Birds, Part II: Anatidae to Alcidae. Slate Creek Press, Point Reyes Station, California, USA. Close ) for age-related criteria based on molt patterns in the very similar White-tailed Kite (Elanus leucurus), which appear to be similar for Black-shouldered Kite. See Molts for molt and plumage terminology. Sexes are similar in Juvenile Plumage and differ slightly in later plumages; definitive appearance is typically assumed at the Second Basic Plumage. Timing of plumages (fresh vs. worn) may generally equate with peak molt in November‒March but can occur year-round (see Phenology).

Natal Down

Hatchlings fully downy. First down (nessoptile) described as fawn, sandy, or pale brownish; second (mespotile) down pale gray (6 Marchant, S., and P. J. Higgins, eds. (1993). Handbook of Australian, New Zealand and Antarctic Birds. Vol. 2. Oxford University Press, Melbourne. Close ).

Juvenile (First Basic) Plumage

Differs distinctly from later plumages in having crown, nape, and breast variably washed rufous-brown to brown with dark shaft streaks; back feathers brown to gray-brown with white tips forming boldly scaled appearance; rectrices with brown subterminal marks (more extensive distally) and black shaft streaks; upperwing coverts (including black lesser coverts) dull and tipped white; remiges narrower and with distinct white tips, the tertials washed brown. See also Bare Parts regarding iris color changes with age.

Formative Plumage

Variable. Can be similar to Juvenile Plumage but with crown, nape, and chest band slightly whiter (with less brown) and back mixed with gray formative feathers, or similar to Definitive Basic Plumage but with some to most juvenile upperwing coverts and juvenile flight feathers retained (rarely all wing coverts can be replaced), narrow, worn and brown, the greater coverts and remiges with white tips. Most to all rectrices abraded and with dark subterminal marks if not bleached off (occasionally can be completely replaced with white formative feathers). Replaced formative lesser coverts are black, contrasting with more worn and slatier juvenile coverts with whitish fringes if not worn off. In some birds tertials can be replaced are are contrastingly fresh and gray; a few inner primaries and some secondaries may also occasionally be replaced, as can occur in White-tailed Kite, but study is needed on this in Black-shouldered Kite. See also Bare Parts regarding iris color changes with age. Sexes of many birds with more complete Preformative Molts (especially males) can be distinguished, as in Definitive Basic Plumage.

Second Basic Plumage

Second Basic Plumage has not been documented in Black-shouldered Kite but, in White-tailed Kite, some birds can retain juvenile outer primaries or secondaries (among s4 and s7‒s8) during the Second Prebasic Molt and can be aged (8 Pyle, P. (2005). Remigial molt patterns in North American Falconiformes as related to age, sex, breeding status, and life-history strategies. Condor 107(4):823–834. Close ,7 Pyle, P. (2008). Identification Guide to North American Birds, Part II: Anatidae to Alcidae. Slate Creek Press, Point Reyes Station, California, USA. Close ). Other birds following complete Second Prebasic Molts may retain some juvenile characters such as white fringing to some greater coverts and/or broader white fringing on the remiges (especially the inner primaries). Study is needed on what proportion of second-year Black-shouldered Kites can be aged.

Definitive Basic Plumage

Female. Generally a gray-and-white bird with distinct black patches to the ocular area, upperwing, and underwing. Forecrown white, becoming pale to medium grayish on the hind crown, nape, and back, scapulars and rump. Rectrices white, often becoming stained brown near the tips when worn. Sides of head whitish to grayish white with grayish lores and the ocular feathers in front of and above eye black, forming a masked appearance, the black extending as a short superciliary stripe above and behind eye. Marginal coverts at bend of wing white; upperwing lesser and median coverts otherwise black, forming distinct patch; greater coverts, alula, and remiges from above dark gray, the primaries and most secondaries with dark shafts. Underparts white. Underwing secondary coverts and secondaries from below are white and the lesser primary coverts are black, forming a distinct black patch to the underwing. The underwing greater primary coverts and primaries from below are dark gray to blackish, becoming darker distally.

In both sexes, definitive basic flight feathers are broader than juvenile feathers, more truncated at the tips, and lack white fringes (except for thin ones when very fresh). Molt clines from more worn to fresher feathers following molt sequences among primaries and secondaries (see 8 Pyle, P. (2005). Remigial molt patterns in North American Falconiformes as related to age, sex, breeding status, and life-history strategies. Condor 107(4):823–834. Close , 7 Pyle, P. (2008). Identification Guide to North American Birds, Part II: Anatidae to Alcidae. Slate Creek Press, Point Reyes Station, California, USA. Close ) are present. Prebasic molts can be suspended for breeding or incomplete, resulting in, e.g., fresher inner than outer primaries. In some cases Staffelmauser (or stepwise) molt may ensue, with two sets of basic primaries indicating Third Basic Plumage or later (cf. 9 Herremans, M. (2000). Cases of serial descendent primary moult (Staffelmauser) in the Black-shouldered Kite. Ringing and Migration 20:15–18. Close , 10 Pyle, P. (2006). Staffelmauser and other adaptive strategies for wing molt in larger birds. Western Birds 37(3):179–185. Close , 7 Pyle, P. (2008). Identification Guide to North American Birds, Part II: Anatidae to Alcidae. Slate Creek Press, Point Reyes Station, California, USA. Close ). See also Bare Parts regarding iris color changes with age.

Male. Similar to Definitive Basic female but head completely bright white, including crown to nape and sides.

Aberrant Plumages

A formative bird photographed (below) in Indigo, Victoria, Australia, on 21 April 2023, was leucistic showing largely or entirely white body feathering, pallid lesser wing coverts, and otherwise white to pallid wing feathers from above but, interestingly, a more normal pattern to the underwing feathering.

General

Molt and plumage terminology follows Humphrey and Parkes (11 Humphrey, P. S., and K. C. Parkes (1959). An approach to the study of molts and plumages. Auk 76(1):1–31. Close ), as modified by Howell et al. (12 Howell, S. N. G., C. Corben, P. Pyle, and D. I. Rogers (2003). The first basic problem: a review of molt and plumage homologies. Condor 105:635–653. Close ). Under this nomenclature, terminology is based on evolution of molts along ancestral lineages of birds from ecdysis (molts) of reptiles (13 Pyle, P., S. N. G. Howell, D. I. Rogers, and C. Corben (2024). Moult terminology: envisioning an evolutionary approach. Journal of Avian Biology 2024:e03169. Close ), rather than on molts relative to breeding season, location, or time of the year, the latter generally referred to as “life-cycle” molt terminology (14 Jenni, L., and R. Winkler (2020). Moult and Ageing of European Passerines. Second edition. Bloomsbury, London, UK. Close ). Black-shouldered Kite exhibits a Modified Basic Strategy (c.f. 12 Howell, S. N. G., C. Corben, P. Pyle, and D. I. Rogers (2003). The first basic problem: a review of molt and plumage homologies. Condor 105:635–653. Close , 15 Howell, S. N. G. (2010). Peterson Reference Guide to Molt in North American Birds. Houghton Mifflin Harcourt, Boston, Massachusetts, USA. Close ), including incomplete-to-complete prebasic molts and a limited-to-incomplete preformative molt but no prealternate molts (6 Marchant, S., and P. J. Higgins, eds. (1993). Handbook of Australian, New Zealand and Antarctic Birds. Vol. 2. Oxford University Press, Melbourne. Close ), as it the case in the similar Black-winged Kite (Elanus caeruleus) (9 Herremans, M. (2000). Cases of serial descendent primary moult (Staffelmauser) in the Black-shouldered Kite. Ringing and Migration 20:15–18. Close ) and White-tailed Kite (Elanus leucurus) (7 Pyle, P. (2008). Identification Guide to North American Birds, Part II: Anatidae to Alcidae. Slate Creek Press, Point Reyes Station, California, USA. Close ).

Prejuvenile (First Prebasic) Molt

Complete, in the nest, primarily in August to January in southern populations but potentially at all times of the year in other populations. No information on this molt (into Juvenile Plumage) in Black-shouldered Kite.

Preformative Molt

Based on examination of Macaulay Library images, the Preformative Molt is variable, including most feathers of the head and scattered feathers on the back and breast in some birds, to most or all body feathers and secondary coverts, some tertials and inner primaries, and two to all 12 rectrices in others (see images under Formative Plumage), as is the case with White-tailed Kite(7 Pyle, P. (2008). Identification Guide to North American Birds, Part II: Anatidae to Alcidae. Slate Creek Press, Point Reyes Station, California, USA. Close ). Reports of complete Preformative Molts (6 Marchant, S., and P. J. Higgins, eds. (1993). Handbook of Australian, New Zealand and Antarctic Birds. Vol. 2. Oxford University Press, Melbourne. Close ) may have been based on the Second Prebasic Molt. Timing of the Preformative Molt is likely in October-April or later in southern populations but potentially at all times of the year in other populations; body feathers may be replaced first followed by protracted molt of wing coverts and remiges replaced.

Second and Definitive Prebasic Molts

Complete, primarily November-March in southern populations but potentially at all times of the year in other populations (6 Marchant, S., and P. J. Higgins, eds. (1993). Handbook of Australian, New Zealand and Antarctic Birds. Vol. 2. Oxford University Press, Melbourne. Close ).

Molt of one to a few primaries and secondaries can sometimes initiate during incubation, suspend for chick feeding, and resume after chicks have fledged in White-tailed Kite(7 Pyle, P. (2008). Identification Guide to North American Birds, Part II: Anatidae to Alcidae. Slate Creek Press, Point Reyes Station, California, USA. Close ) and this should be looked for in Black-shouldered Kite. Suspension allows individuals to take advantage of quiet period to molt, especially by females, which are often fed by males during incubation. Primaries are replaced distally (p1 to p10), secondaries are replaced proximally from s1 and s5 and distally from the tertials (often bilaterally from t2), and rectrices may be replaced in sequence r1–r6-r3-r4-r5 on each side of tail, with some variation likely (16 Underhill, L. G. (1986). A graphical method to determine the ordering of moult, illustrated with data from the Blackshouldered Kite Elanus caeruleus. Bird Study 33(2):140–143. Close , 6 Marchant, S., and P. J. Higgins, eds. (1993). Handbook of Australian, New Zealand and Antarctic Birds. Vol. 2. Oxford University Press, Melbourne. Close ).

Prebasic molts appear to be complete in many if not most Black-shouldered Kites, as based on examination of Macaulay Library images, but some in individuals 1-4 outer primaries and 1–6 secondaries (often among s3–s4 and s7–s10) can be retained during incomplete prebasic molts; retained juvenile feathers following an incomplete Second Prebasic Molt would indicate Second Basic Plumage. Incomplete molts can lead to Stafflemauser patterns including two waves of molt through the primaries, as in other Elanus kites (9 Herremans, M. (2000). Cases of serial descendent primary moult (Staffelmauser) in the Black-shouldered Kite. Ringing and Migration 20:15–18. Close , 7 Pyle, P. (2008). Identification Guide to North American Birds, Part II: Anatidae to Alcidae. Slate Creek Press, Point Reyes Station, California, USA. Close ), with two waves or sets of basic feathers indicating a bird in at least Third Basic Plumage (10 Pyle, P. (2006). Staffelmauser and other adaptive strategies for wing molt in larger birds. Western Birds 37(3):179–185. Close ). Staffelmauser occurs when large birds lack the time to complete flight-feather molt in a single year and it has the ultimate benefit of preventing larger gaps in the wing enabling flight and foraging during peak molting periods (8 Pyle, P. (2005). Remigial molt patterns in North American Falconiformes as related to age, sex, breeding status, and life-history strategies. Condor 107(4):823–834. Close ).

From Marchant and Higgins (6 Marchant, S., and P. J. Higgins, eds. (1993). Handbook of Australian, New Zealand and Antarctic Birds. Vol. 2. Oxford University Press, Melbourne. Close ) along with examination of Macaulay Library images.

Bill and Cere

The bill is black to gray-black at all ages. The cere is dull greenish to yellowish in adults; in nestlings it is grayish becoming yellowish gray in juveniles and attaining the color of adults in the first year. The gape can be orange-yellow and the inside of the mouth pink and black (cf. ML567629671).

Iris and Facial Skin.

In adults the iris is bright orangish red to red. In nestlings it is brown, becoming dull amber in juveniles, gradually becoming brighter amber during the first year, and changing to dull to bright orange at about a year of age and into the second year. The orbital ring is grayish in nestlings and juveniles becoming black during the first year and in adults. See images under Plumages as well as those below.

Tarsus and Toes

The legs and feet in adults are yellow to orangish yellow, with black talons. The legs and feet can be paler creamy yellow in some adults, perhaps during non-breeding periods of the year, becoming brighter during prebreeding periods. In nestlings they are creamy to rich buff, becoming yellow (sometimes duller than in adults) in juveniles and attaining adult-like color quickly thereafter.

Falco axillaris Latham, 1801, Supplementum Indicis Ornithologici, p. 9.—Australia.

Latham based his scientific binomial on his own earlier description of the “Axillary Falcon”, which Latham informs us was based on a specimen kept alive for two months, “being fed with small birds, fish, and etc.”. Original material from Latham, or used by him to describe new species, is generally rare in museum collections (17 Steinheimer, F. D. (2005). The whereabouts of pre-nineteenth century bird specimens. Zoologische Mededelingen Leiden 79(3):45–67. Close ), although a substantial body of specimens belonging to the Leverian Museum, which was a regular recourse of his, was purchased by Leopold von Fichtel (1770‒1810) on behalf of what is now the Naturhistorisches Museum Wien (NMW), not all of which have survived (see 18 Bauernfeind, E. (2004). Bird specimens from the Leverian Museum: documentation and present holdings at the NMW. Festschrift für Univ. Prof. Dr. Horst Aspöck. Denisia 13:555–565. Close ). There is no evidence that the specimen upon which Latham based this species still exists.

Synonyms:
Elanus notatus Gould, 1838, Synopsis of the Birds of Australia, part 4, appendix, p. 1.—New South Wales. Of two specimens labeled New South Wales from Gould held in what is now the Academy of Natural Sciences at Drexel University, Philadelphia, Stone (19 Stone, W., and G. M. Mathews (1913). A list of the species of Australian birds described by John Gould, with the location of the type-specimens. Austral Avian Record 1(6–7):129–180. Close ) selected ANSP 1973 (a male) as his “type” [= lectotype], making ANSP 1972 (a female) the paralectotype.
Elanus axillaris parryi Mathews, 1912, Novitates Zoologicae 18:251.—Parry Creek, northwest Australia. The holotype, an adult male collected on Parry Creek, 5 miles west of Trig. Station, East Kimberley, on 27 January 1909 by J. P. Rogers, is held at the American Museum of Natural History, New York (AMNH 531543) (20 Greenway, J. C. (1973). Type specimens of birds in the American Museum of Natural History. Part I: Tinamidae–Rallidae. Bulletin of the American Museum of Natural History 150(3):209–345. Close , 21 LeCroy, M. (2017). Addenda and corrigenda to type specimens of birds in the American Museum of Natural History, Part 1 (by James C. Greenway, Jr. 1973. Bulletin of the American Museum of Natural History 150(3): 207–346). Bulletin of the American Museum of Natural History 150(3)(Supplement):1–218. Close ). Said to be paler on the upperparts (22 Mathews, G. M. (1912). A reference-list to the birds of Australia. Novitates Zoologicae 18:171–455, 607–656. Close ), but Mathews had sunk his own name into synonymy just four years after describing it (23 Mathews, G. M. (1916). The Birds of Australia. Volume 5(2–4), pp. 160–440, pls. 245–274. Witherby & Company, London, UK. Close ).

In the past (e.g., 24 Peters, J. L. (1931). Check-list of Birds of the World. Volume 1. Harvard University Press, Cambridge, MA, USA. Close , 25 Stresemann, E., and D. Amadon (1979). Order Falconiformes. In Check-list of Birds of the World, Volume 1, 2nd edition (E. Mayr and G. W. Cottrell, Editors), Museum of Comparative Zoology, Cambridge, MA, USA. pp. 271–425. Close ) referred to by the specific name notatus (see above) on the grounds that Latham’s senior synonym axillaris was supposedly unidentifiable and could have applied to Letter-winged Kite (Elanus scriptus); this view is, however, unfounded (26 Schodde, R., and I. J. Mason (1980). Nocturnal Birds of Australia. Landsdowne, Melbourne, Australia. Close , 27 McAllan, I. A. W. and M. D. Bruce (1989). The Birds of New South Wales: A Working List (1988). Biocon Research Group, Turramurra, New South Wales, Australia. Close ). This species has traditionally been thought to form a species-group (or superspecies) with Black-winged Kite (Elanus caeruleus) and White-tailed Kite (Elanus leucurus) (28 Parkes, K. C. (1958). Specific relationships in the genus Elanus. Condor 60(2):139–140. Close , 29 Husain, K. Z. (1959). Notes on the taxonomy and zoogeography of the genus Elanus. Condor 61(3):153–154. Close , 30 Clark, W. S., and R. C. Banks (1992). The taxonomic status of the White-tailed Kite. Wilson Bulletin 104(4):571–579. Close ); all three species have been considered conspecific in the past, but they differ variously in plumage, morphology, and behavior.

None definitely reported.

The genus Elanus is monophyletic. Mindell et al. (31 Mindell, D. P., J. Fuchs, and J. A. Johnson (2018). Phylogeny, taxonomy, and geographic diversity of diurnal raptors: Falconiformes, Accipitriformes, and Cathartiformes. In Birds of Prey (J. Sarasola, J. Grande and J. Negro, Editors), Springer, Cham, Switzerland. pp. 3–32. Close ) recovered two major branches within the group, one comprising Black-winged Kite (Elanus caeruleus), and the other consisting of the present species, Letter-winged Kite (Elanus scriptus), and White-tailed Kite (Elanus leucurus) (see also 32 Starikov, I. J. and M. Wink (2020). Old and cosmopolite: molecular phylogeny of tropical–subtropical kites (Aves: Elaninae) with taxonomic implications. Diversity 12:327. Close , 33 Keirnan, A., T. H. Worthy, J. B. Smaers, K. Mardon, A. N. Iwaniuk, and V. Weisbecker (2022). Not like night and day: the nocturnal letter-winged kite does not differ from diurnal congeners in orbit or endocast morphology. Royal Society Open Science 9:220135. Close ); they found the morphologically not dissimilar Pearl Kite (Gampsonyx swainsonii) of the Neotropics to be sister to Elanus, with these two genera diverging in the Early Miocene, whereas splits within Elanus appear to have occurred exclusively in the Pliocene (31 Mindell, D. P., J. Fuchs, and J. A. Johnson (2018). Phylogeny, taxonomy, and geographic diversity of diurnal raptors: Falconiformes, Accipitriformes, and Cathartiformes. In Birds of Prey (J. Sarasola, J. Grande and J. Negro, Editors), Springer, Cham, Switzerland. pp. 3–32. Close ). Earlier, Griffiths et al. (34 Griffiths, C. S., G. F. Barrowclough, J. G. Groth, and L. A. Mertz (2007). Phylogeny, diversity, and classification of the Accipitridae based on DNA sequences of the RAG-1 exon. Journal of Avian Biology 38(5):587–602. Close ) also reported that Gampsonyx and Elanus are sister taxa and basal to all other accipitrid genera. More recently, Starikov and Wink (32 Starikov, I. J. and M. Wink (2020). Old and cosmopolite: molecular phylogeny of tropical–subtropical kites (Aves: Elaninae) with taxonomic implications. Diversity 12:327. Close ) suggested that the subfamily Elaninae, comprising Elanus, Gampsonyx, and Chelictinia (sensu 35 Lerner, H. R. L., and D. P. Mindell (2005). Phylogeny of eagles, Old World vultures, and other Accipitridae based on nuclear and mitochondrial DNA. Molecular Phylogenetics and Evolution 37:327–346. Close ) should be treated at family level, as the Elanidae, on the basis of molecular, cytological, morphological, and ecological data, with Gampsonyx potentially meritorious of its own subfamily within this new arrangement.

Not reported.

Also known as the Australian Black-shouldered Kite (e.g., 2 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ).

Information needed.

Australia: breeds mainly in southeast corner, from north of Cairns (Queensland) to west side of Eyre Peninsula (South Australia), but also in southern and northwestern coastal strip of Western Australia, and around Darwin and Melville Island (Northern Territory) (2 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ); occasional in Tasmania.

Grassland and other sparsely wooded habitats with ground cover of 30–150 cm tall (2 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ), including savanna, coastal sand-dunes (especially in south and west of range) (2 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ), tree-lined watercourses (2 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ), farmland, heath, market gardens (2 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ) and vacant urban grassy land. Nesting male in southeastern Australia hunted mostly in woodlands with rank grasses and avoided grazed grasslands with few perches (36 Barnes, T. (2005). Foraging, habitat use and nesting of the Black-shouldered Kite Elanus axillaris in the Australian Capital Territory. Australian Field Ornithology 22(2):58–66. Close ). Found from sea-level to 1,500 m (2 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Nests in trees amidst open forest (36 Barnes, T. (2005). Foraging, habitat use and nesting of the Black-shouldered Kite Elanus axillaris in the Australian Capital Territory. Australian Field Ornithology 22(2):58–66. Close ).

Resident populations in temperate coastal lowlands; others dispersive, partly migratory and irruptive in response to plagues of prey (e.g. rodents and grasshoppers). Longest ringing recovery ca. 1,000 km (from South Australia to eastern New South Wales) and has also been recorded as a vagrant on King Island, Flinders Island, and Tasmania (2 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Present only in Snowy Mountains, New South Wales, during snow-free months (37 Osborne, W.S. and Green, K. (1992). Seasonal changes in composition, abundance and foraging behaviour of birds in the Snowy Mountains. Emu 92(2):93–105. Close ). Irregular in semi-arid zone; regular wintering on coast.

Mostly small rodents (especially house mice) (38 Debus, S. J. S., G. S. Olde, N. Marshall, J. Meyer, and A. B. Rose (2006). Foraging, breeding behaviour and diet of a family of Black-shouldered Kites Elanus axillaris near Tamworth, New South Wales. Australian Field Ornithology 23(3):130–143. Close ); occasionally small birds, lizards and large insects (especially grasshoppers) (2 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Forages mostly by hovering head into wind (2 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ), then dropping onto prey on ground with wings held high above back, but occasionally hunts from perches and during level flight (36 Barnes, T. (2005). Foraging, habitat use and nesting of the Black-shouldered Kite Elanus axillaris in the Australian Capital Territory. Australian Field Ornithology 22(2):58–66. Close ). In one study, 77% of 44 attacks successful (38 Debus, S. J. S., G. S. Olde, N. Marshall, J. Meyer, and A. B. Rose (2006). Foraging, breeding behaviour and diet of a family of Black-shouldered Kites Elanus axillaris near Tamworth, New South Wales. Australian Field Ornithology 23(3):130–143. Close ). Consumes prey either in flight or on perch. Primarily hunts diurnally but sometimes nocturnally on moonlit nights (2 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ).

Considered to be mainly silent except in breeding season. Vocalizations rather weak though sometimes persistently given, a high whistled "chee-chee-chee" or "chip-chip-chip", as well as a harsh wheezing "skee-ah" (2 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Repertoire includes harsh, harmonic, chatter and whistle vocalizations, with high-amplitude long duration calls indicating high degree of stress (39 Jurisevic, M. A. (1998). Comparison of vocalisations of Australian falcons and Elanine kites. Emu 98(1):1–12. Close ). Chatter vocalizations are of short duration (0·08 seconds) and low amplitude, and given in nest defence, but may turn into longer calls in response to increased threat, e.g. by approaching human intruder (39 Jurisevic, M. A. (1998). Comparison of vocalisations of Australian falcons and Elanine kites. Emu 98(1):1–12. Close ). Harsh vocalizations emitted when bird alarmed or agitated, and by female during copulation, aerial transfer of prey and by birds fleeing territorial intruders (39 Jurisevic, M. A. (1998). Comparison of vocalisations of Australian falcons and Elanine kites. Emu 98(1):1–12. Close ). Whistle-type calls, sometimes given monotonously, usually considered to be given in contact, but may possess a harsh component in response to human presence (39 Jurisevic, M. A. (1998). Comparison of vocalisations of Australian falcons and Elanine kites. Emu 98(1):1–12. Close ).

Season variable, throughout most of year (March–January) with peaks in autumn and spring (mostly June–October in east and November–January in west) (2 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ); continuous when food abundant, when pairs have two broods per year. Solitary, or in loose colonies when prey abundant. Aerial displays include solo and mutual high-circling, butterfly flights, talon-grappling and cartwheeling (2 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Platform of sticks 27–45 cm wide, 10–15 cm deep (2 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ), lined with green leaves; placed 4–35 m above ground in canopy of live tree, rarely on artificial structure. Both sexes gather nest material, but only female builds (36 Barnes, T. (2005). Foraging, habitat use and nesting of the Black-shouldered Kite Elanus axillaris in the Australian Capital Territory. Australian Field Ornithology 22(2):58–66. Close ). Usually 3–4 eggs (2–5), size 37.9–45.8 × 30.1–34.5 mm (40 Olsen, P. D., and T. G. Marples (1993). Geographic variation in egg size, clutch size and date of laying of Australian raptors (Falconiformes and Strigiformes). Emu 93:167–179. Close ); incubation 29–34 days; chicks have fawn first down, then pale grey second down; fledging 33–38 days (exceptionally 42+ days) (2 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ); post-fledging dependence ca. 1 month (41 Read, D. G. (2005). Observations on parent/young behaviour in a pair of Black-shouldered Kites Elanus axillaris. Australian Field Ornithology 22(3):109–121. Close ). Age at first breeding probably one year. Oldest ringed bird 3.5 years. Of all eggs laid 73% hatch, and 54% result in fledglings.

Not globally threatened (Least Concern). CITES II. Common and widespread; has increased in range and numbers in cleared and farmed areas of south and southwest (2 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ) Australia in response to creation of habitat and introduction of suitable prey. Unlike many raptors, effects of DDT on eggshell thickness and consequently breeding success from late 1940s onwards not considered to be significant (42 Olsen, P. D., P. Fuller, and T. G. Marples (1993). Pesticide-related eggshell thinning in Australian raptors. Emu 93:1–11. Close ).