AUSTRALIAN 20 WATCHER

AUSTRALIAN BIRD WATCHER 1989, 13, 20-29

The Breeding Biology of the Australian Falco longipennis

by E.C. METCALF, 11 Peel Street, O'Connor, A.C.T. 2601

Summary The breeding cycle of a pair of Australian Hobbies Falco longipennis was observed intensively for six consecutive seasons, from 1980 to 1986, in suburban Canberra, A.C.T. Nests were inspected on or near anticipated hatching dates and nestlings were banded. The Hobbies used vacated nests of the Australian Raven Corvus coronoides on electricity pylons, and discarded the nest lining. Incubation usually began in the first week of November and lasted an estimated 28-31 days. Nestlings fledged in January, at 35-41 days, the post-fledging period lasted ten weeks and the pair raised 12 young in six years (0-3, mean 2 young per year; modal brood size 3). Behavioural data are presented on courtship, copulation, territorial defence, parental roles in the laying, incubation, nestling and post-fledging periods, and development of the young.

Introduction The Australian Hobby Falco longipennis has not been the subject of a major study. For a widely distributed and relatively common raptor, the species is little known. In reviewing its biology, Czechura & Debus (1986) emphasised the need for additional field data, particularly on its breeding cycle. In Canberra (35 "20'S, 149 °04 'E) single Hobbies can be seen throughout the winter months. Breeding activity starts with pairing in mid September, and the young may leave the area as late as early April. Breeding is dependent on nests of the Australian Raven Corvus coronoides in suitable condition. One such nesting territory was readily observed from a suburban house for six years, and this paper reports on the results of those observations.

Methods From 1980 to 1986 a Hobby nesting territory was observed intensively throughout the breeding season. The most frequently used nest site could be monitored all day (heat haze permitting) through 12 x 40 binoculars at a distance of 1400 m, with a 4 o field of view each side of the nest. At important times the nest was visited and viewed with 7 x 40 binoculars. Long-distance monitoring occurred at intervals throughout the day while on-the-spot viewing was confined mainly to the early morning (starting 15-30 minutes before sunrise) or evening (finishing 15-30 minutes after sunset), times of greatest Hobby activity. From the 1980-81 season onwards, the young when present were banded and nest inspections provided accurate information on hatching dates. We were unwilling to disturb the earlier in the cycle, so laying data are based on behavioural changes and are therefore approximate. Despite one attempt the adults were not marked. However, with constant watching, the hunched attitude of the larger female versus the more upright stance of the male made identification reasonably certain. Definite sex designations were made only when both adults could be accounted for. We assumed that the bird coming off eggs at sunrise was the female. Also the precision with which patterns of behaviour are repeated over the years is striking and has been useful in confirming earlier assumptions. VOL. 13 (1) MARCH 1989 Australian Hobby: Breeding Biology 21

Results Nest In the area concerned, Australian Ravens build or refurbish their nests in July, lay eggs in August, hatch young in late August or early September and, most commonly, fledge young in the first week of October. Nests are a solid stick structure lined with bark from Red Stringybark Eucalyptus macrorhyncha or sometimes sheep's wool. In the area studied, three nests were placed near the top of electricity pylons and only one in a tree. If given a choice, the Hobbies under observation preferred pylon nests and moved 400 m to one so situated rather than 30 m to a tree nest. They returned to the original area the following year when the Ravens refurbished the original nest. The Ravens leave their nest in perfect condition with the cup lining intact. The Hobbies leave a flattened, messy platform and are dependent on the Ravens to render it habitable for the next season. If not reconstructed by the Ravens, the nests often fall down in the second year. None of the Australian Hobbies observed was seen to add eucalypt leaves or other lining material to the nest. However, material was sometimes discarded, starting about two days after the Ravens fledged, and was observed many times during the 3-4 weeks of the Hobbies' pre-laying period. The female Hobby spent much of this time on the nest, often shuffling and turning around in the cup for long periods. The discarding of nest lining, undertaken only by the female, occurred between dawn and 1000 h. She made 3-9 'transporting' flights at about one-minute intervals on each of the days on which it was observed. Courtship Courtship feeding occurred throughout the pre-laying period. During the early stages, the male usually transferred food to his mate in an aerial drop. However in the week before laying, prey was delivered to the female at the nest or at a nearby transfer perch. The female was obviously hungry and ate all the items provided, mostly small birds, without waiting for the male to pluck them. After prey delivery the male either perched near his mate or flew away from the territory. At times the male remained perched near the female at the nest for as long as 90 minutes. Throughout the pre-laying period both sexes appeared to use nocturnal roosts away from the nest, in one case c. 100 m away. However, both arrived at the nest before sunrise. Most nest-based activity, including discarding of lining, courtship feeding and copulation, occurred in the morning. Often the birds were not observed at all during the afternoon, although the nest was frequented again in the evening. Copulation Copulation was first observed two days after nest appropriation. It was noted on approximately 50% of observation days up until four days before incubation appeared to commence, with a frequency of 24 times over 16 days and a maximum of 4 times in a day. Most (approximately 80%) of observed copulations occurred in the first 150 minutes after sunrise. Copulation usually took 4-5 seconds (range 1-10 seconds), the single 10 second maximum being 22 days after nest appropriation and 10 days before continuous incubation began. Most copulations occurred on the nest or on one of the small wires attached to the nest pylon, however in some years copulation was observed only in a tree used for food transfer. Territorial defence There was considerable interaction between the resident pair and other Australian Hobbies during the pre-laying period. This occurred particularly in the week before laying, and continued into the first week of the incubation period. At times one or AUSTRALIAN 22 METCALF BIRD WATCHER two additional Hobbies soared in company with the residents, and an 'intruder' occasionally perched close ( (1 m) to the occupied nest. In 1985-86 conspecific visitation was observed ten times during an 80 day period in the breeding season. Usually there was no sign of aggression during such visits, although the resident female occasionally flew towards the perched intruder and gave an aggressive call; there was no violent chasing and the male did not react. It was not possible to determine the age of the intruders, or if they 'Nere banded. Conversely, the pre-laying period was characterised by mutual harassment between the resident Australian Hobbies and other species nesting nearby: Brown Goshawk Accipiter fasciatus, Hieraaetus morphnoides and Australian Kestrel Falco cenchroides. Most encounters appeared almost 'casual', without physical contact or prolonged high-speed chasing. However, with the approach of fledging the female Hobby was seen in determined pursuit of the neighbouring Goshawk. In one year about a month after the fledging date a probably juvenile Hobby was taken by a juvenile female Goshawk but managed to escape (Olsen 1982). Other species involved in mutual harassment with the Australian Hobbies were Sulphur-crested Cockatoo Cacatua galerita, Galah C. roseicapilla, Australian Magpie Gymnorhina tibicen, Strepera graculina and S. versicolor. Throughout the breeding season the female Hobby was observed to defend only in the immediate area of the nest. The male seemed responsible for defence of other areas of the territory. Human visitors to the territory were attacked only if the pylon was climbed. Both sexes were involved in defence against climbers, the female playing the major role. Once, the male perched immobile with prey about 50 m away while the female harassed the banding party for 15 minutes.

Laying As laying approached, the female Australian Hobby's activities centred more and more on the nest. While the male continued to soar above the tree canopy over the territory, the female became much less active. The period of close female attachment to the nest commenced approximately 10 days before laying and increased in intensity for 5-6 days. Long periods were spent sitting, standing or moving around in the nest. Nest attendance then declined in the 4-5 days before laying. On a few occasions during the final days before laying, the female flew to nearby Raven nests and sat in them for periods of 2-3 minutes. In 1982-83 the pair changed nest sites during the pre-laying period. In the 1985-86 season an attempt was terminated six days after incubation had apparently commenced, and another attempt was made at a disused Raven nest three pylons away. This attempt also failed, and a third (successful) attempt occurred back at the original pylon. Two females (by size and posture) were present in the territory throughout this period, the extra bird being noted only when all three Hobbies were visible.

Incubation Incubation commonly began in the first week of November although it commenced on 14 October in 1985. Observations suggested that incubation was intermittent until the clutch was complete or nearly so; this is supported by data from one clutch monitored by J. Olsen, in which all three eggs hatched within 24 hours. For two days after behaviour patterns suggested that laying was in progress, the female continued to leave the nest after sunset for a distant roost and was seen to return to the nest at dawn. On the third night she roosted near the nest and on the following day close incubation appeared to have started. However, throughout incubation the eggs were left uncovered for periods of up to 20 minutes, most often in the early morning when the female ate her first meal for the day. VOL. 13 (1) MARCH 1989 Australian Hobby; Breeding Biology 23

Australian Hobby Falco longipennis Plate 9 Drawing: Peter Slater AUSTRALIAN 24 METCALF BIRD WATCHER

In 1982, on the twenty-third day after presumed clutch completion, the male fed his mate close to the nest for 20 minutes. This meal started at 1900 h after a humid day of 26 o C maximum. Three days later the male provided food to his mate on the power line 100 m from the nest. On this occasion the eggs were uncovered for only five minutes. If the female was absent for longer periods, up to 80 minutes, the male incubated the eggs. Male inc:Jbation usually followed prey transfer to the female; the female was not seen to capture any of her own food during the incubation period. During prey transfers there was usually no solicitous behaviour from the female, although on one occasion (day 22 of incubation) she was heard calling at the nest. The male brought prey to the transfer perch and the female usually flew to the perch, took the food and ate it at the nest. Occasionally if the male was late the female waited on the transfer perch, on one occasion for 20 minutes while the eggs were left uncovered. Prey was usually eaten fully feathered, although the male occasionally plucked prey if it was not immediately claimed. On one occasion he held prey for 1V2 hours. The incubation period was estimated as 28-31 days (Table 1). In 1981-82 the three eggs were pipping when the nest was inspected on the thirtieth day after the clutch was estimated to be completed. All three eggs hatched early the next morning. The nestling period Until the eggs hatched, the male Australian Hobby usually perched quietly and was not often seen. In the first week after the eggs hatched, he frequently circled above the tree canopy to c. 30 m, in a 300 m radius around the nest, and behaved aggressively towards a variety of other birds. The female's activities were largely restricted to the nest. The male continued to provide all food (via a transfer perch or aerial drop), the female feeding small morsels to the nestlings from a standing position on the nest rim. As the nestling period proceeded, larger pieces of food were given to the young. Prey was seldom plucked. Only the female fed the young in the first 19 days after hatching (1982-83), however the male fed the nestlings on the twentieth day. By this stage the female spent extended periods off the nest, and the young were more visible and active. Flapping activity by the nestlings was not observed until 29 days after hatching. Thereafter flapping activity, particularly by the dominant nestling, was frequent and vigorous. During rain, the female covered her young at 24 days after hatching. On two occasions during light rain the female flew slowly through foliage, apparently gathering moisture. She then perched for some time, wings spread as if to dry. In 1985 a juvenile behaved similarly, 24 days after fledging (Metcalf & Metcalf 1988). In the late nestling period, both parents brought food to the nest. However, from the thirtieth day after hatching the rate of feeding declined. Generally the last meal of the day was delivered 30 minutes before sunset. However, in three years the nestlings were fed up to 28 minutes after sunset on the eve of the fledging of the first nestling. These evening meals took 10-13 minutes, suggesting that large prey items were involved. At one of these deliveries the incoming parent signalled its arrival with a long whistle 20 seconds before reaching the nest.

Fledging All young (n=l2) fledged in January; the nestling period was 35-41 days (Table 1). One bird flew at 32 days during a banding attempt. Though hatching of three eggs in 1981-82 occurred within 24 hours, first flights of the three young were separated by 24 and 48 hours (Table 1). VOL. 13 (1) MARCH 1989 Australian Hobby: Breeding Biology 25

Table 1 Breeding parameters for an Australian Hobby territory at Canberra, A.C.T. 1978-1986

Breeding Estimated No. & sex Fledging Nestling Post-juvenile season incubation of fledged dates period dispersal periotf' young (days) 1978-79 unknown 1+? unknown unknown unknown

1979-80 unknown 3? unknown unknown young present (site 1) on 3.4.80

1980-81 unknown 2F, IM 27.1.81 unknown young present (site I) (banded) 28.1.81 on 4.4.81 30.1.81

1981-82b 3.11.81- 2F, 1M 4.1.82 32c 27 .3.82 (site 1) 3.12.81 (banded) 11.1.82 39 13.1.82 41

1982-83 7.11.82- 3M 12.1.83 35 29.3. 83 (site 2) 8.12.82 (banded) 13.1.83 36 16.1.83 39

1983-84 unknown- lF, 1M 9.1.84 40 23.3 .84 (site 2) 30.11.83 (banded) 10.1.84 41

1984-85 no sign of nil nil nil niJd nesting

1985-86e 27.11.85- lF 28.1.86 35 19.3.86 (site 1) 25 .12.85 (banded) •Jaying and hatching dates known to ± 1-2 days bhatching dates confirmed by nest inspection (3 hatched within 24 h) cflew during banding

At the fledging stage, each morning the parents called kee-kee . . . in flight or from perches up to 100 m from the nest. They appeared to be enticing the young to fly. The young made many short flights, mostly less than 100m but some up to 400 m were made to specific trees in the territory where they perched for up to 30 minutes. Their flight was weak and fluttering, and landings were clumsy. On all flights greater than 100 m the fledglings were accompanied by an adult. In years when less than three young were raised, the male supplied more food than the young could consume immediately. The female fed the young with small pieces of prey at a variety of perches until they were temporarily sated. When not hunting, the male often perched for lengthy periods near the nest. The post-fledging period The young Hobbies remained in the locality for some 70 days after their first flight, developing their flying and hunting skills. During the first 14 days they developed in stages, with new abilities or behaviours appearing every three days. They appeared to learn by experience and by imitating the adults. AUSTRALIAN 26 METCALF BIRD WATCHER

Throughout the first 14 days the young roosted on the nest at night. They were no longer fed as a group but individually, first by the female which dismembered prey for them on perches. From the seventh day the male took a major role in feeding the young, and the female avoided them. Prey items were mostly small birds, fed whole to one fledgling at a time on the male's plucking tree. From the tenth day the male dropped whole prey items for the young to catch in flight, and from the thirteenth day the female also provided whole prey in aerial drops. Meals were characterised by loud calling of parent and offspring. On the ninth day of the 1985-86 post-fledging period, the male provided a young Hobby with a whole small bird. The fledgling manipulated it ineffectually for about 40 minutes, then began a low, plaintive moan. The male immediately seized the prey and for several minutes refused to release it, mantling closely. Finally he yielded it back to the fledgling, which mantled it for two minutes, plucked some feathers then began to eat hungrily when it struck meat. It took 20-30 minutes to consume the prey and it appeared unskilled, with a need to learn by doing. Mantling behaviour, not seen previously, became common practice for protecting prey from siblings and adults. One fledgling cached prey on the tenth day of the post-fledging period. At the end of the fortnight young were seen perched on the pylon, transferring prey from feet to bill and back. This 'prey play' motion was performed in flight from the fifteenth day post-fledging; the young moved large prey back and forth in an apparent checking motion, but may have eaten insects on the wing. Flying skills developed through stages from weak, fluttering flight between nest and perches (days 1-3) through gliding (days 4-6) and low, fast tandem flight (days 7-9) to high flying at c. 100 m and aerial exchange of prey (day 10). At the end of the first fortnight the young performed fast foliage-brushing flight. On the fourteenth day, following a shower of rain that ended a hot, dry period, the young followed the female on what appeared to be a moisture-gathering flight through the undergrowth. The party of flew rapidly through low vegetation, brushing damp foliage with their wings. (The young Hobbies had been noted previously to bath in moist foliage and grass as early as the tenth day post-fledging). By the end of the first fortnight the young were roosting at night in trees, and thereafter the nest was not defended although the young occasionally visited it. For the first time, Ravens and Magpies inspecting the nest for food scraps on day 15 were left unmolested. However, from this time on there was much mutual harassment between the young Hobbies and the larger birds of the area including Galahs, Sulphur-crested Cockatoos, Australian Magpie-larks Grallina cyanoleuca and Magpies. No attempt was made to capture these birds. The first recorded capture of prey was a small bat taken on day 23 of the 1982-83 post-fledging period (Metcalf 1983). Generally the young appeared to catch little food of their own for the first seven weeks after fledging, and were still being fed by an adult. However, around day 50 the young started to take an interest in the smaller birds. An adult Hobby flying 70 m above the canopy released live prey for a fledgling to catch, and once a young bird accompanied an adult into the suburban hunting area. By this time, early March, the easterly migration of honeyeaters may have provided easy prey for the young Hobbies which were now frequenting an area of2 sq. km around the nest, and soared on thermals to great heights. From day 60 to day 70 the young dispersed, and only single Hobbies were seen thereafter. In the 1981-82 and 1982-83 seasons, the Hobby post-fledging period lasted a little over 10 weeks (Table 1). In both cases it ended with an apparent group display that may mark a seasonal change in behaviour. The female rose to a high perch on a eucalypt VOL. 13 (1) MARCH 1989 Australian Hobby: Breeding Biology 27 and called a prolonged, clear kee-kee .. . whereupon the young flew towards her in a group, and for some minutes they performed diving and chasing aerobatics with loud calling. They then rose to about 500 m and flew off in different directions. Thereafter, Hobby sightings fell into the usual winter pattern of one per month. H. Nix (pers. comm.) has observed similar behaviour in about March of several years in Canberra: groups of 3-4 Hobbies at midday in clear skies, soaring high, swooping, performing aerobatics and chittering, after which Hobbies are seen singly. One of the young Hobbies, banded at the Canberra nest in the 1980-81 season and still present in the territory in April 1981, was recovered in Brisbane, 920 km NNE, on 3 May 1981 some 29 days later.

Discussion Australian Hobbies frequently breed in corvid nests (Carnaby 1933; Brandon 1938; Cupper & Cupper 1981). As reported here, appropriation of occupied nests occurs, sometimes within days of the young corvids fledging (North 1912; Boekel1980; Metcalf 1982). Some observers have claimed that the nest may then be repaired and/or lined (North 1912; McGilp 1923; Brandon 1938), although this is atypical for Falco (Cade 1982) and there are no convincing descriptions of this for Australian Hobbies. I have not seen such behaviour. Although species including the Merlin F. columbarius are known to line nests (Newton et al. 1978), Czechura & Debus (1986) considered there to be insufficient evidence for such behaviour in the Australian Hobby. However, the discarding of lining material has been noted previously for the Australian Hobby (Morris 1976) and other falcons (Cramp & Simmons 1980; Steyn 1982) and may account for observations of nest material being carried. The cosy lining favoured by winter-nesting Ravens may require ventilation for summer use by the Australian Hobbies. Fiuczynski (1987) noted that the European Hobby Falco subbuteo will remove sticks from the nests of European Crows Corvus corone and also that to attract this hobby artificial nests must be shallow enough to give an all-round view. As was the case at Canberra, male falcons are more active in pre-laying aerial display than their mates, especially as laying draws near (Cade 1982). As in many birds, male falcons also provision their mates with food during the pre-laying and incubation periods (Newton 1979; Cade 1982). This phenomenon has been reported for the Australian Hobby (Key 1938; Morris 1973; Fleming 1976). Courtship (supplementary) food transfers in Falco include both aerial drops and direct acceptance at the nest or on a nearby perch (Cade 1982), as observed for the Hobbies at Canberra. Both courtship feeding and copulation are known to commence at least one month before laying in some falcons (Newton 1979; Cade 1982), as was the case here. copulation is often associated with courtship feeding and it commonly occurs on the nest or at a food transfer perch (Newton 1979; Cramp & Simmons 1980; Cade 1982). As reported here for the Australian Hobby, most copulatory activity occurs in the early morning (Cade 1982). The early morning seems to be the most important time of day for pre­ laying nest-based action in raptors generally (Newton 1979). Male falcons are largely responsible for territory establishment and defence (Newton 1979). Although initial territory establishment could not be attributed to either sex at Canberra, the male Australian Hobby played the main role in both territorial display and territory defence in the pre-laying period. There is usually a 48-60 hour interval between the production of each egg in falcon clutches, which typically number 3-4 eggs (Cade 1982). Confirmatory observations (nest inspections) are required on laying interval and early incubation routines of the AUSTRALIAN 28 METCALF BIRD WATCHER

Australian Hobby. Most incubation is carried out by female falcons, however males often incubate the eggs while their mates feed (Cade 1982). Hollands (1984) first reported male Australian Hobbies to share incubation, and male incubation spells )1 hour as noted for the Hobbies at Canberra have been reported for several species including the F peregrinus, Gyrfalcon F rusticolus and Merlin (Newton 1979; Cade 1982). Male falcons capture most or all of the food eaten by the pair during incubation, as was the case at Canberra. The incubation period estimated for the Hobbies at Canberra (28-31 days) is typical of small falcons (Cade 1982). Previous estimates have put the Australian Hobby's incubation period at 30+ to 35 days (Hollands 1984; Czechura & Debus 1986), but this may represent the time from laying to hatching and not actual incubation time, which may begin in earnest after the clutch is nearly complete (cf. Newton 1979). It also compares with estimates of 28-33 days for the European Hobby in which egg coverage increases from 36% on day 1 of incubation to 75% by day 5 and 90% by day 6 (Fiuczynski 1987). Female falcons are very attentive to the nest and young in the first fortnight after hatching (Newton 1979). As reported here, males rarely visit the nest during this period. The female feeds the downy nestlings on small strips of flesh torn from prey captured by the male. As found for Australian Hobbies at Canberra, male falcons join in the direct provision of food to their young in the third or fourth week of the nestling period (Newton 1979). Similarly, female falcons often begin hunting by the fourth week of the nestling period, by which time the young start to become much more active on the nest (Cade 1982). The nestling period found here is longer than expected for a falcon the size of the Australian Hobby, given Newton's (1977) formula for Falco: nestling period = 26.94 + 0.013 x female mass (days). Taking mean female mass as 293 g (Baker-Gabb 1984), the mean Australian Hobby nestling period would be predicted as 30-31 days. Previous estimates for the species have been 35 days (Hollands 1984) and 28-35 days (RAOU Nest Record Scheme). The nestling periods for the European Hobby and African Hobby F cuvieri have been reported as 28-34 days and approximately 30 days, respectively (Cramp & Simmons 1980; Brown et al. 1982). There are no previous data on reproductive success of Australian Hobbies. In the years following the 1982-83 drought at Canberra there was a crash in the local small bird and large insect populations; shortage of food may explain the decline in brood size (Table 1). Comparatively little has been written about falcon post-fledging periods. Newton (1979) has reviewed the literature on adults 'enticing' the young to fly, and the adult role in developing flight and capture mastery via aerial drops of prey (sometimes live), refusal to release prey, and mutual flying activity; all are recorded here for the Australian Hobby. No presumed 'moisture-gathering' flight similar to that reported here has been described. This could be an artefact of most post-fledging field observations having been carried out in cooler, moister areas. Fiuczynski (1987) recorded foliage bathing and 'training' flights through foliage as well as dust bathing for the European Hobby. Recently fledged European Hobbies and Peregrine Falcons develop in flight mastery through experience (see Newton 1979; Cramp & Simmons 1980; Cade 1982); the young birds operate over a progressively expanding area, and many of the aspects of juvenile behaviour are similar to those documented here for Australian Hobbies. European Hobbies first capture insects 4-12 days after fledging, although their parents continue to supply food beyond this time. Newton (1979) gave the post-fledging period of small falcons as 2-3 weeks, however this estimate was derived from few and incomplete data. No previous estimate of the Australian Hobby's post-fledging period has been VOL. 13 (1) MARCH 1989 Australian Hobby: Breeding Biology 29 made, and there is no previous record of actual post-juvenile departure from the natal territory. Further investigation of the apparent pre-departure social interaction is warranted.

Acknowledgements Firstly, I must acknowledge the Hobbies which provided me with a great source of interest following my stroke. But to Tom Aumann, who took my copious field notes and first draft and wrought them into this paper, gratitude of the highest order is due. I also thank those intrepid climbers and banders R. Bartos, D. Mallinson, R. Metcalf, J. Olsen and T. Ross for helping to verify observations and for general comments. I appreciate the time given by Jerry & Penny Olsen to reading the manuscript but take full responsibility for the end result. I also wish to thank David Purchase, formerly of the Australian Bird Banding Scheme, for providing information on band returns of Australian Hobbies. Special thanks go to Diana Metcalf, for without her generous help with transportation at all hours of the day (usually 0500 h) none of the fine detail of this paper would have been possible.

References Baker-Gabb, D.J. (1984) , 'Morphometric data and dimorphism indices of some Australian raptors', Corella 8, 61-63. Boeke!, C. (1980), 'Birds of Victoria River Downs Station and of Yarralin, Northern Territory, part 1', Aust. Bird Watcher 8, 171-193. Brandon, T. (1938), 'Notes on the hawks observed in the upper north of South Australia during 1937', S. Aust. Omithol. 14, 153-160. Brown, L. , Urban, E.K. & Newman, K. (1982) , The Birds of Africa, vol. I, Academic Press, London. Cade, T.J. (1982), The Falcons of the World, Collins, London. Carnaby, I.C. (1933), 'The birds of the Lake Grace district, W.A .', Emu 33, 103-109. Cramp, S. & Simmons, K.E.L. (1980), Handbook of the Birds of Europe, the Middle East and North Africa. The Birds of the ltestem Palaearctic, vol. 2, Oxford University Press, London. Cupper, J. & Cupper, L. (1981) , Hawks in Focus , Jaclin, Mildura. Czechura, G.V. & Debus, S.J.S. (1986), 'The Australian Hobby Falco longipennis: a review', Aust. Bird Watcher 11, 185-2