3.79 19

Field notes on the Letter-winged Elan us scriptus at Werribee, Victoria, 1977. By JAROSLAV KLAPSTE, 6/15 Southey St., Elwood, Victoria, 3184. Drawings by Malcolm Taylor from field sketches by the author. Summary The occurence, abundance and behaviour of the Letter-winged Kite at Werribee, Victoria is described. These kites are part of a wider invasion into Victoria and south-eastern from far inland. They were observed and studied in the above mentioned locality for a period of about five months. Comparisons in behaviour and appearance with the Black-shouldered Kite are discussed as well as problems of field identification. · Introduction There are twenty-four species of diurnal of prey in Australia and six of them are endem;c. These endemics are little known because they are rare or live in remote areas of the interior. For several reasons, Elanus scriptus is one of the most interesting. The Elanus consists of four species. Two of them occur in Austra­ lia, namely, the Black-shouldered Kite, E. notatus and the Letter-winged Kite E. scriptus. The Black-winged Kite E. caeruleus is the most wide­ spread, ·living in Africa, southern Asia and Europe (Portugal only). It has not yet been recorded in Australia, but it does come as close as Timor and New Guinea. The fourth species is the White-tailed Kite E. leucurus. It occurs in central and south America and, very rarely, in the southern United States. The kites of the genus Elanus have large eyes for their size and this together with their broad head gives them a somewhat owl-like appearance. I have in mind hawk-owls of the genus Ninox rather than the Barn Owls Tytonidae and the rest of the typical owls Strigidae. In fact the Letter­ winged Kite looks more owl-like than the three other kites of the genus, because it has the largest and roundest black orbital patch. There is seldom opportunity to observe and study the Letter-winged Kite in the settled areas of southern Australia. The following ob:;ervations are from the Melbourne and Metropolitan Board of Works Farm, Werribee, Victoria (Werr;bee township = 3r 55'S lat., 144° 44' E long.). Some of my ob:;ervations differ from those of Beruldsen ( 1971), due possibly to behaviour varying according to the kite's locality. Finding the Letter-winged Kites While at the M.M.B.W. Farm, Werribee, on January 21, 1977 at 1630 hrs. ( d.s. t.), Peter Klapste and I saw four of what at first appeared to be Black-shouldered Kites. They were perching together on a dead branch of a small Melaleuca tree, about three metres above the ground. When they took wing they were immediately recognized as Letter-winged Kites. They sat on the fence about 200m away. We followed and took several photo­ graphs of them in flight and also sitting on the fence. The similar Black­ shouldered Kite was also common at that time in this area. Next day, January 22, 1977, we visited the farm again with Wallie Coles and found one Letter-winged Kite in company with a Black-shouldered Kite at 0930 hrs. Later we met Fred T. H. Smith with a group of observers and 20 KLAPSTE 3.79 ·------~~ told them of our findings. When we met them again several hours later they showed us the roosting place of 14 Letter-winged Kites which they had just found about 1 km from our original sighting. This locality became one of the main roosting places of these kites on the farm. About 1 km further north I found two other roosting places. All four main roosting places known to me were in a line of about 2 km. From that ti me until now, (May 1978), I have observed the kites there many times ( see Table I), always with Peter Klapste and often with other observers. It was interesting to hear these people describe the kites as "looking sleepy". In the literature this kite is described as a nocturnal (Beruldsen (1971), Mason (1976), Morris (1976) ). I recorded its activity throughout a twenty-four hour period and found that in the later night hours it is as little active as it is during midday hours. Field Observations The invasion of the Letter-winged Kites at the M .M.B.W. Farm, Werribee seems to have brought with it larger numbers of Black-shouldered Kites. The Letter-winged Kite is a highly sociable bird in contrast to the Black-shouldered Kite. But in the Werribee area J'iotatus also became a gregarious bird in the company of scriptus. Both species were always seen together. This was an advantage, enabling easy comparisons to be made in general appearance, , flight and behaviour. In the Werribee area, the Black-shouldered Kite, not usually a very shy raptor, was much shyer than the Letter-winged Kite. E. notatus became noticeably tamer in the compc: ny of scriptus, and allowed closer approach and observation than normal. When these two species were disturbed from perching together, it was always notatus which first took flight. In the summer the kites were usually, but not always, perching on dead branches, under the shade of living branches-- and at that time they were roosting on higher trees than they were later -- dur:ng the autumn and early winter. There are many exceptions, but the average perch height was 8-15 metres. In autumn the k ~ t e s were observed perching consistently lower in the trees and more often in the d :::ad trees -- some of which stood isolated in paddocks. The average roosting height in autumn and winter was lower than earlier in the year -­ usually between 1-6m from the ground. In these seasons the Letter-winged Kites were starting to rest on the ground in groups, close together, while the Black-shouldered Kites were often perching in the trees nearby. These "congregating grounds" were in the cattle grazi ng paddocks, in short grass and often far from trees. As many as twenty-two E. scriptus were seen sitting together on the ground in a small area of approximately five sq uare metres. Whether perching or on the ground an observer was allowed within twenty metres before the kites would take to the wing. On one occasion a bird remained sitting (whilst the other fourteen took wing) and allowed two of us to approach very closely even though we were coming from different directions. We thought that thi s bird may have been injured or sick, but it took wing in noiseless flight as we approached to five metres. During the period of time when the kites occupied the area I did not notice any preference for a specific species of tree. T hey used several species of Eucalyptus, both living and dead for perching. Less often they used cypress-, probably because they are not as common there. With some exceptions perching on fences only occurred when the kites were disturbed from their roosting trees, or "congregating grounds" . "Owl-like" facial features of peering Letter-winged Kites. M.M.B.W. Farm, Werribec, Victoria. Plate 7 Photo by J aroslav Klapste

Two Letter-winged Kites in a close-contact roost attitude. M.M.B.W. Farm, Werribee, Victoria. Plate 8 Photo by J aroslav Klapste 22 KLAPSTE 3.79

I was surprised to see the kites perched for as long as an hour, in what appeared to be a peculiarly uncomfortable position, on high, vertical branches (see sketch). This happened more often in the summer, shortly after their arrival in the area, and when they were disturbed from their roosting branches. I noticed many times that they rest lengthwise on branches (see sketch). On hot summer days they often perched with open beak, and sometimes with wings deeply drooped or partly open. However they normally kept the wings folded over the tail or slightly drooped under the tail where only the extreme tips of the primaries were crossed (see Plate ) . As many as seventeen birds have been seen perched together on one branch. Five birds was the average. Distance between perching birds was usually about 20-30 em, sometimes more, and sometimes only five em. Actual contact between two birds has been noticed many times (see sketch). In the Werribee area solitary Letter-winged Kites were seen only rarely. Sooner or later groups of birds were noticed of this very gregarious species. I have seen Letter-winged Kites there, usually in groups of up to 20-30 birds together but often a smaller group was also nearby. The largest number I have seen together was sixty-eight birds. It was on February 19, 1977 in bright sunny weather. Peter Klapste tried to photo­ graph these kites in flight. All the birds of the roosting colony eventually took wing- flying high over the intruders, and provided an opportunity to be counted. This most spectacular sight was shared by Chris Doughty. Only the Letter-winged Kites were counted but there were also about ten Black-shouldered Kites in this locality. In light of previous experience in the area it can be estimated that about twenty or more Letter-winged Kites were also unnoticed in the general area. The Letter-winged Kites were not very vocal. On the early morning of February 4, 1977, I was lying on my back under the trees where the kites were roosting. Watching these birds I was disturbed by a call a Letter­ winged Kite uttered when a Little Falcon Falco longipennis flew near one of them and subsequently perched in the next tree. The call was strong and harsh, "shreep-shreep" reminding me of a call of the Whiskered Tern Chlidonias hybrida. During one period of time spent among these kites the other call I heard was similar to that of the Black-shouldered Kite and of the Silver Gull Larus novaehollandiae. It sounded like "kar" repeated three times. I heard it only four times and it was always uttered when an arriving bird had insufficient space to alight on a branch amongst the other kites. Pellets: During my observations of the Letter-winged Kites I twice witnessed the ejection of pellets. The ejections preceded several long "yawnings" and were accompanied by vigourous vertical headshaking. The measurement of the pellets were: 46 x 24 mm and 39 x 26 mm respectively. I found fourteen other pellets under the roosting trees. Some of them may be from the Black-shouldered Kites. They all were cylindrical in shape and greyish in colour. Average measurement 36 x 22 mm; smallest 29 x 18 mm; largest 46 x 26 mm. On a "congregating ground" I found only one pellet 37 x 24 mm, undoubtedly from the Letter-winged Kite as the Black-shouldered Kites do not use these "grounds". 3.79 Letter-winged Kite 23

..-p ~~ __.:;:--...--:;::::;-...... ------~-----Sitting lengthwise along branch.

Contact, and separate perching.

Letter-winged

uneven angle perching. 24 KLAPSTE 3.79

The Other Raptors: There is no scarcity of food for birds of prey at the Werribee Farm, but no plagues of rodents or locusts have been recorded which can be especially attractive for the Letter-winged Kites. In the area occupied by the Letter-winged Kites I observed nine other species of birds of prey. Six of them were commonly seen. These were the Black-shouldered Kite Elanus notatus; Whistling Kite sphenurus; Brown Goshawk A ccipiter fasciatus; Swamp Harrier Circus aeruginosus; Brown Falcon Falco berigora and Nankeen Kestrel Falco cenchroides. Three rarer species for the area (with date of observations), are Spotted Harrier Circus assimilis (19.3.77); Black Falcon Falco subniger (19.3.77; 12.4.77 and 13.6.77); Little Falcon Falco longipennis ( 4.2. 77). The Letter-winged Kites have been closely associated only with Black-shouldered Kites. Werribee Farm: Numbers of E. scriptus and E. notatus. NUMBER OF DATE TIME E. SCRIPTUS E. NOTATUS 21.1.1977 1630 4 4 22.1. 0930 1 1 30.1. 1500 14 2 4.2. 1400 14 7 22.1. 2100 32 12 23.1. 0830 26 14 19.2. 1500 68 10 5.3. 1030 36 15 19.3. 1000 28 14 26.3. 1500 25 11 6.4. 1530 32 10 12.4. 1800-2400 34 8 15.4. 1800-2400 28 4 16.4. 1030 22 4 8.5. 1330 20 4 14.5. 1600 12 2 15.5. 1030 20 8 22.5. 1530 11 2 28.5. 1630 26 6 5.6. 1600 22 4 13.6. 1100-1500 28 8 20.6. 0630-0900 7 2 26.6.1977 1030 7 3 (This column not corrected for daylight saving time- Hon. Editor.) In the literature the "Letter-wing" is usually described as a nocturnal bird. But this habit varies according to the circumstances of a particular locality and it is connected with its food supply as well as with weather conditions. Certainly it is more active in darkness than in daylight. This does not mean that it is active all night. During sunset the birds first start hunting. On one occasion I saw also the Black-shouldered Kite hunting in darkness. The Letter-winged Kite in the late night hours is as little active as it is during daylight. Three times I saw the Letter-winged Kite hunting during 3.79 Letter-winged Kite 25

Letter-winged Kites in flight. M.M.B.W. Farm, Werribee, Victoria. Plate 9 Photo b y Peter K lapste 26 KLAPSTE 3.79 daylight; always afternoon, in cloudy weather. By contrast, I saw one bird during sunny weather soaring high over the roosting trees where the other kites were perching motionless at the same time. The Letter-winged Kites are highly sociable only in their roosting colonies, otherwise every bird hunts on its own. I found that these birds were most active about two hours after sunset. It is very possible that the hunting activity starts again several hours before sunrise. As I wanted to prove this I arrived at their roosting colony at night on June 20, 1977, at 0330 hrs. and found two birds at 0630 Ius. Only seven birds were observed. It was overcast, and behaviour and hunting time may differ from that in better conditions. The return of the kites to their roosting trees was very inconspicuous. Identification of the two similar species E. notatus and E . scriptus is easy whilst birds are in flight. Perching birds must be identified with care. T he Letter-wing;o:d Kite generally looks greyer, usually with a larger black patch at the shoulders, but there are some variations. Both species are about the same size. I found that the most significant (and only reli able) features for the correct field identification are the extension of the black orbital patch and colour of the legs and feet. Legs and feet of E. notatus are bright yellow, often with an orange tinge, whilst legs and feet of E. scriptus varied from dull yellowish-white to pale (dull) yellow. T he Black-shouldered Kite has a small relatively narrow black patch in front of the eye and also behind the eye, where it is "pointed", giving an impression of a perfect brow. There is no black below the eye (see sketches) . The Letter-winged Kite has a relatively large and wide black patch in front of the eye. From close up, there is a clearly visible narrow black extension above, behind and below the eye, which paralells the shape of the orbit. It is not pointed posteriorly as in E. notat us (see sketches). This is incorrectly illustrated in the field guides by Slater (1970) and Morris (1976) . Condon (1968) has only an overhead illustration of the Letter­ winged Kite. In summer I saw several immature birds among the adult Letter-winged Kites. The coloration was similar to that of the immature Black-shouldered Kite, but with the characteristic black underwing pattern. Intensity of the black in the underwing pattern varied slightly for immatures as well as for adults, but it was always the best identification feature. The active flight of the Letter-winged Kite has a slower wing beat than that of the Black-shouldered Kite. This can sometimes be more conspicuous than at other times. Whilst gliding E . scriptus holds its wings less raised and less crooked at the shoulder than E. notatus. In hovering flight I d~d not notice any difference between scriptus and notatus. References Beruldsen, G. R., 1971. The Letter-winged Kite, Elanus scriptus. Aust. Bird Watcher 4 : 46-52. Condon, H. T., 1968. Field Guide to the Hawks of Australia. 4th ed; Melbourne, B.O.C. Mason, I. J., 1976. "Complete Book of Australian Birds". (H. J. Frith, ed.) Reader's Digest Services, Sydney. Morris, F. T., 1976. Birds of Prey of Australia. A Field Guide. Lansdowne, Melbourne. Slater, P., 1970. A Field Guide to Australian Birds. Non Passerine. Rigby, Adelaide. ABW