THE WESTERN AUSTRALIAN NATURALIST

Vol. 30 28th February 2017 No. 4

THE DISTRIBUTION, STATUS MOVEMENTS AND DIET OF THE FOREST RED-TAILED BLACK COCKATOO IN THE SOUTH-WEST WITH EMPHASIS ON THE GREATER REGION, WESTERN

By R.E. JOHNSTONE 1, T. KIRKBY 2 and K. SARTI 1 1 Department of Terrestrial Zoology, Western Australian Museum, Locked Bag 49, Welshpool DC, 6986, Australia 2 20 Buckingham Road, Kelmscott, Western Australia 6111, Australia

ABSTRACT The Forest Red-tailed Black Cockatoo (Calyptorhynchus banksii naso) is a large, iconic forest cockatoo endemic to the south-west corner of Western Australia. It is listed as Threatened under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 and Vulnerable under the Western Australian Wildlife Conservation Act 1950. It has experienced a severe decline in numbers and range since European colonisation. Over the past 20 years there has been a dynamic change in the foraging ecology of many birds in the northern Darling Range (adjacent to the Perth metropolitan area) driven mainly by their discovery of Cape Lilac as a new food source. Flocks that were once largely sedentary have now developed regular movements onto the Swan Coastal Plain and in some places have established new roost and breeding sites. Furthermore in 2014–2015 there was also a massive flowering and nutting of Marri (the main food throughout its range) in the northern Darling Range and on parts of the Swan Coastal Plain and during late 2015 and throughout 2016 there was a considerable movement of birds from the hills onto the southern Swan Coastal Plain to forage on Marri seed. Despite this abundance of food on the Swan Coastal Plain and in the adjacent hills region, almost no birds were recorded breeding in 2016, perhaps a result of

193 food quality rather than quantity, or perhaps a result of the energy required with the extensive movements to and from foraging sites. The availability of Jarrah and Marri seed is becoming increasingly scarce in many areas in the face of habitat modification, climate change and fire. The implications are that the Forest Red-tailed Black Cockatoo may become more dependent on some introduced species for food in some areas and this will impact on their breeding biology.

INTRODUCTION It is listed as Threatened under the Commonwealth Environment The Forest Red-tailed Black Protection and Biodiversity Con- Cockatoo (Calyptorhynchus banksii servation Act 1999 and as Schedule naso) is a large, iconic forest 3 fauna [species that are ‘rare or cockatoo, endemic to the south- likely to become extinct, as west of Western Australia. This vulnerable fauna, are declared to subspecies occurs in the humid be fauna that is in need of special and subhumid south-west protection’] under the Western mainly the hilly interior, north Australian Wildlife Conservation to Gingin (formerly to Dan- Act 1950. It is currently the daragan), Gidgegannup, and east subject of a recovery program to Mount Helena (formerly (Chapman 2008). Toodyay), Chidlow, Wooroloo, Wundowie, The Lakes, Christmas This paper provides details of the Tree Well, near Brookton, Ban- changing foraging ecology of nister (formerly to Wandering), many birds in the northern Mount Saddleback, Kojonup, Darling Range over the past 20 Rocky Gully, the upper King years. The foraging ecology of River, Porongurup Range and some populations in the north- Green Range. It was formerly ern Jarrah-Marri forest in recent common, but is now rare to times has meant that flocks that uncommon and patchily distri- were largely sedentary have now buted over most of its range. Its developed regular movements distribution on the northern onto the Swan Coastal Plain and Swan Coastal Plain was confined in some places established new largely to the eastern zone north roost sites and breeding sites. This to Gingin and south to the movement has led to an Armadale-Byford and Serpentine erroneous impression in the -North Dandalup regions, with Perth region that this subspecies small breeding populations at is expanding its range and Baldivis, Mundijong, Stake Hill, increasing in abundance. Karnup and more recently in the Perth area at Murdoch and DISTRIBUTION possibly Perry Lakes. The Red-tailed Black Cockatoo

194 Calyptorhynchus banksii (Latham, subspecies: C. b. macrorhynchus 1790) is widely distributed in occurs in the Kimberley region; eastern and northern Australia, C. b. samueli in the mid-western and south-western Australia. In region and C. b. naso from the far Western Australia there are three south-west of the State (Figure 1).

Figure 1. Distribution of Red-tailed Black Cockatoo subspecies in Western Australia.

195 Forest Red-tailed Black Cockatoo Chidlow, Wooroloo, Wundowie, (Calyptorhynchus banksii naso) The Lakes, Christmas Tree Well, This subspecies occurs in the Westdale, 10 km west of Brook- humid and subhumid south- ton, North Bannister (formerly to west mainly the hilly interior, Wandering), Mount Saddleback, north to Gingin (casually e.g. Kojonup, Rocky Gully, the upper December 1983 and Boonan- King River, Porongurup Range arring November 2012), (formerly and Green Range (Figure 2). to Dandaragan), Guildford Masters and Milhinch (1974) (resident here in colonial times noted it as scarce in the Northam now only rare or casual visitor, district, only observed west of see below), Bindoon, Gidge- the Avon River each autumn in gannup, and east to Mount Wandoo forest at Glen Avon and Helena (formerly Toodyay), west of Clackline in flocks up to

Figure 2. Distribution of Forest Red-tailed Black Cockatoo C. b. naso including historical records.

196 50; suddenly disappeared and last Bindi Bindi, Wyalkatchem, sighting was of five birds north Merredin, Walgoolan and Kool- of Clackline in 1971. yanobbing and is a casual visitor On the Swan Coastal Plain its further south at Kwolyin and status in historical times is Narembeen. uncertain. G.F. Moore noted a While the range of C. b. naso has black cockatoo with a red tail contracted over the past 50 years, about his homestead near in comparison the range of Guildford in 1831. It was listed by C. b. samueli has expanded south- Gould (1865) as “appears to be wards and this may be continu- most numerous in the colony of ing judging from southern the Swan River, where it inhabits records at Kwolyin, Narembeen all parts of the country”. W.B. and a recent report in September Alexander (1921) listed it for the 2015 of a flock of five birds Swan River District as “only feeding in a paddock on the occasionally seen in the district, upper Darkin River (Westdale, being a bird of the inland regions Beverley Shire) within the range of the State. The reasons for the of C. b. naso. occasional visits to coastal districts are unknown”. Serventy MOVEMENTS AND CHANGES IN (1948) noted that it was “never STATUS AND ABUNDANCE reported nowadays from the Swan Coastal Plain”. Storr and The northern subspecies samueli Johnstone (1988) list it as a rare is quite dispersive undertaking visitor in flocks up to 30, regular seasonal movements (November to May) to eastern whereas naso on the other hand parts of the Swan Coastal Plain, is considered generally very presumably from the adjacent sedentary with strong fidelity to Darling Range. On the Swan home range territory. In the past Coastal Plain it is currently rare, there has been some isolated but resident at some sites vagrancy of pairs and small (although patchily distributed) flocks onto the Swan Coastal at Mundijong, Baldivis, Karnup, Plain. For example a small flock Stakehill, near Lake McLarty, was observed by A. Chapman at Pinjarra, Coolup, Meelup, Good- Lake Joondalup on 25 April 1977; ale Sanctuary, Lake Clifton area, two were observed by P. Griffin Dawesville and Wokalup (Storr- in Booragoon bushland on 27 Johnstone Bird Data Bank). May 1978; six observed drinking by J. Stuart at Rosalie Park (near Inland Red-tailed Black Cockatoo Shenton Park) on 11 March 1981; (Calyptorhynchus banksii samueli) and three seen by B. Gardiner This subspecies occurs in the over Guildford Grammar School western arid and semiarid regions in late April 1984. of Western Australia, from the Banding recoveries of 37 chicks De Grey River south to Eneabba, that were banded between 1997

197 and 2011 with some 35 re- distance of 24 km from its natal sightings of 11 birds (including area. Another bird of interest is a fledglings to adults 13 years old) male chick banded at Nest 47 at showed that juvenile-immature 31 Mile Road (Jarrahdale State birds moved on average less than Forest) in December 2003 was 3 km from their natal tree and observed at Gleneagle on 29 older birds were recorded August 2005 (a distance of 1.3 moving up to 19 km. For example km) and observed in Bungendore a male chick banded at Nest 2 on Park on 21 March 2011, a distance 23 November 1997 was re-sighted of 14 km from its natal area. ten times between January 1998 Other banding records from and November 2003 moving Department of Parks and Wild- only 1–3 km from the nest site life include immature birds over that period and in July 2004 banded at Kaarakin Conser- it was observed (with a female vation Centre in Martin on 9 and immature) at Kelmscott six June 2009 and recovered at and a half years after banding Araluen on 15 June 2009 after and a distance of 6 km from the colliding with a vehicle (a nest site. A male chick banded at distance of 7.1 km); another on 24 Nest 18 in Bungendore Park (near March 2011 and recovered at Armadale) on 4 January 1998 was Manning after colliding with a observed seven times between 6 vehicle on 5 June 2012 (a distance April 1998 and 9 March 2003 of 18 km); another banded on 27 moving between 0.2 and 3 km July 2012 recovered at Wattle from its nest site. Another male Grove after colliding with a chick, banded at Serpentine on 11 vehicle on 2 August 2012 (a July 2000, was observed at Myara distance of 10.8 km). on 31 May 2013 and again on 3 July 2014 (13 and 14 years later) Records suggest that Forest Red- some 7 km from its nest site. tailed Black Cockatoos are Noteworthy also is a female generally sedentary. This seden- banded as a chick in Nest 40 at tary nature of most flocks in the Bungendore Park on 18 April Perth Hills is backed up not only 2002 that was observed four by banding but also by obser- times in and around Bungendore vations and photographs of a Park between 2 June 2003 and 13 distinctive aberrant female with October 2005 (moving less than 3 yellowish patches on nape and km from the nest site) and on 15 throat and two white outer July 2010 it was injured (after primaries (Figure 3) observed at colliding with a car) at Lynwood Cardup in February 2006, on a distance of 19 km from its natal Admiral Road in the Byford hills area. Also a female banded as a in August 2007 and near the chick in Nest 529 at Bungendore same site in December 2007, Park on 4 July 2009 was injured, January 2008, February 2008, and later died from vehicle strike August 2008, September 2008, at Carlisle on 29 January 2017 a November 2008, December 2008,

198 Figure 3. Aberrant female Red-tailed Black Cockatoo at Admiral Road, Byford.

March 2009, April 2009 and FORAGING ECOLOGY February 2011 and at Waterwheel There are pronounced differ- Ridge estate, Bedfordale in 2015. ences in the dimensions of the The overall movement being less bill and in the food of the Forest than 10 km during the period Red-tailed Black Cockatoo C. b. 2006–2015. naso and the more northern Further south, a Coolup resident, inland and mid-western sub- A. Robinson (1970), recorded species C. b. samueli. The former small flocks leaving the heavily naso has a large bill (and is mainly timbered Darling Range in 1970 arboreal and the latter samueli and moving out onto the more has a small bill and feeds mainly open coastal plain which he on the ground. noted as unusual.

199 Perth Region on the coastal plain and up to 30 Since 1995 there has been a very birds were roosting in Lemon- dynamic change in the foraging scented Gum (Corymbia ecology of many birds in the citriodora) at Murdoch, and by northern Darling Range (adja- November numbers had in- cent to the metropolitan area). creased to over 60. Small This began as a slow expansion of numbers (up to 5) were also foraging range from the Darling roosting in the vicinity of Range, west onto the Swan Shenton Park bushland judging Coastal Plain (mainly south of from some early morning Perth) to foothill localities. Prior observations. By 2011 over 100 to this, sightings of banded birds birds were roosting in tall (banded as nestlings) were within Lemon-scented Gum at Murdoch three km of banding site (natal campus and up to 80 were tree). In the late 1990s small roosting nightly in Marri in the flocks and family groups began western suburbs of Perth, near to alter their daily routine from East Lake, Perry Lakes. During foraging in relatively small home 2011–2012 numbers at the Perry ranges within Jarrah-Marri forest Lakes roost would occasionally to become at first only casual fluctuate from 0–80 birds (M. visitors to the base of the escarp- Owen pers. comm.) and at the ment mainly exploiting fruiting same time numbers at Murdoch Cape Lilac (Melia azedarach) in would increase with some counts some of Perth’s south-eastern of up to 200, so there was suburbs e.g. Byford, Armadale, apparently some movement of Kelmscott and Gosnells. By early birds between these roosts. By 2000 this had extended further 2013 birds were regularly flying north and west as other feeding out from the scarp and visiting sites or opportunities were found fruiting Cape Lilac trees as far in other suburbs including west as Fremantle and Kwinana Thornlie, Lynwood, Queens Park, around 32 km from the Darling Cannington, Kewdale, Bentley, Scarp. On evening of 2 January Belmont, Kensington and by 2017 over 266 birds were recorded 2005 this had extended further in the Perry Lakes-Underwood west and north to Murdoch and Avenue area gathering to roost Kardinya, by 2007 north to (M. Owen pers. comm.) This is the Nedlands and west to Medina. By largest flock ever recorded on the 2009 north to City Beach, Wood- Swan Coastal Plain. Since 2010 lands, Hamilton Hill, Mosman there has also been some Park and Henley Brook, also west vagrancy of flocks (probably to Kwinana and by 2010 further driven by a lack of surface water north to Carine, Joondalup and in home ranges) east into the the Upper Swan. wheatbelt to areas where there Also by early 2010 some of these was previously no historic flocks had established roost sites records of Forest Red-tailed Black

200 Figure 4. Occasional movements from the Darling Range eastwards into the wheatbelt towards Brookton and westwards onto the Swan Coastal Plain.

Cockatoos e.g. near Brookton and politan area it is a common Boyagin Rock, see Figure 4. garden, park and farm tree grown mainly for its shade. It flowers in Cape Lilac (Melia azedarach) spring, just as the new leaves Cape Lilac (White Cedar, Persian emerge, and flowering continues Lilac), a native of Indomalesia through into summer. and Australasia (variety in The marble-sized drupes (berry- northern Australia), is a large, like fruits) are produced from seasonally deciduous tree (gen- November to March in branched erally 10–15 m, but up to 40 m) clusters 10–20 cm long, initially with a canopy 6–8 m wide. Trees green then turning light yellow in the south-west of Western in colour at maturity. The leaves Australia appear to be the Persian turn yellow in late autumn and Lilac introduced from Asia fall in winter, but fruits remain (Mabberley and Pannell 2013). On on the tree all winter and the Swan Coastal Plain and gradually become wrinkled and especially in the Perth metro- more whitish. On the Swan

201 Figure 5. Adult male feeding on Cape Lilac in August at Fremantle.

Coastal Plain some trees with Bedfordale in August 1995 when fruits can be seen throughout some members of a small flock the year, including trees with (nine birds) were seen feeding on both old (yellow) and new (green) ripe fruits. There was no fruits. From June to mid- evidence that birds had previ- September, most trees have lost ously been feeding in these trees their leaves and the yellow berry- (i.e. no old or new debris below like clusters are quite visible, see the trees) and some birds perched Figure 5. in the trees appeared unin- terested in feeding while others The Inland Red-tailed Black began feeding at a rapid pace. Cockatoo C. b. samueli has been Within two weeks most drupe recorded feeding on the drupes clusters were gone from those of Cape Lilac at Merredin in the trees and small flocks were eastern wheatbelt of Western foraging on nearby trees. These Australia since the mid-1990s trees were within the home (Stranger 1997) and at Dowerin in range of a large flock and the March 2001. Cape Lilac trees were in a house The first observations of the garden at the edge of an orchard Forest Red-tailed Black Cockatoo not typical habitat for Forest foraging on Cape Lilac were from Red-tailed Black Cockatoo.

202 The movement onto the Swan We have recorded birds feeding Coastal Plain was initially very on ripe Cape Lilac throughout slow. Small flocks and family the year. Trees close to the groups moving in early morning escarpment are stripped first and from roost sites near the western the birds generally start feeding side of the Darling Range to areas in the canopy biting off the at the foot of the range where spray of fruits and then eating they could forage on Cape Lilac each fruit one at a time whilst and if the food resources were holding the rest of the spray, see suitable discovering new sites Figure 5. Experienced birds have often close by moving in a been observed taking less than mosaic pattern. This opportun- four seconds to remove the seed istic movement in populations whilst immatures can take up to that generally exhibit strong site fifteen seconds. One banded bird fidelity was quite exceptional for fleshed ten fruits in 35 seconds. Once the canopy fruits are gone, this subspecies. This could be the birds move to the lower correlated with the decline in branches. By the end of July most the availability or nature of of the trees close to the escarp- Jarrah and Marri in the northern ment have been stripped of forest block or possibly an fruits but many trees further increase in the number of birds west on the coastal plain (e.g. moving west to the edge of the around Welshpool, Queens Park, escarpment from the drier east- Kensington) are still heavily ern parts of the Darling Range. In loaded with fruit. At Armadale the long term, however, many of for example, birds begin visiting these birds that are on the move trees loaded with fruits in could be condemned, through January and February and by the loss or change in their forest end of June most trees have been habitat, to become nomads and stripped of fruits and flocks are drifters to parts of the Swan moving further north and west Coastal Plain where food re- onto the coastal plain. Numerous sources are also, or will eventu- trees with fruits are available on ally be, greatly limited. Around the Swan Coastal Plain through- Perth many shires are removing out the year and birds have Cape Lilac trees to control a pest learned the location of these caterpillar species of the White trees and return to the same trees Cedar Moth (Leptocneria reducta) year after year. that is confined to these trees. Noteworthy also is an apparent Because of the limited amount of change in foraging behaviour foraging habitat and the fact with many of the birds visiting that birds quickly exhaust food the Coastal Plain especially those supplies, seasonal fluctuations in around Murdoch, feeding on the numbers have been recorded at ground (Figure 6), a behaviour some roost sites including that is rarely observed in the Murdoch and Perry Lakes. forest.

203 Figure 6. Forest Red-tailed Black Cockatoo feeding on the ground at Murdoch University.

The toxic principles and insecti- on the ground. This behaviour cidal qualities of the seeds, leaves has also changed dramatically in and roots of Cape Lilac are 2016 with numerous observa- discussed by Mabberley and tions of birds feeding on the Pannell (2013) – Cape Lilac fruit ground either on fallen Marri is toxic to pigs and humans (6–8 seed or on nuts dropped by other are a fatal dose in children). species at Christmas Tree Well However, it is unknown what (Brookton Highway), Willowdale, the long-term effects are (if any) Harvey, Myara, Mundijong and of the foraging by Forest Red- Serpentine. This is probably the tailed Black Cockatoos on Cape result of a huge nutting cycle of Lilac. Marri in 2015–16 with a On 12 January 2012 a flock of ten considerable amount of seed birds was observed feeding in the falling onto the ground and canopy of Cape Lilac trees on many species such as Red-capped Quarry Road in Hamilton Hill Parrots clipping nuts from trees and another two were feeding on that has enabled birds to forage the ground below the trees. on these unopened nuts. This was in stark contrast with our observations in the forest Slow foraging expansion (Figure 7). where during the past 20 years of Slow vagrancy affords a species a our study we have fewer than method of discovering new ten observations of birds feeding habitat, which, if environ-

204 mentally suitable, especially food moving up to 19 km from their resources, can result in breeding original nest site which confirms range expansion. It appears their region of origin. For important in this case also as a example birds banded as nest- way of perhaps coping with the lings in Bungendore Park (near changing nature or loss of foods Armadale), have been observed at in the northern Jarrah-Marri Byford and also at Lynwood and forest, perhaps through the Carlisle. impacts of climate change and in The daily routine of birds some cases possibly fire. More leaving the western edge of the likely it could be simply a case of Darling Range at traditional opportunism and the fact that roost sites at or around dawn once they discovered the exten- 06:00–07:00 hrs and flying west, sive Cape Lilac food resource on often high up, wheeling around the plain, early morning move- the top of the scarp for a few ments to and from the Darling seconds before flying out over Range to isolated trees became the drop, then descending and frequent and the birds returned levelling out over the tree tops, each day until the food source to suitable feeding sites, often was depleted and again each year single trees in suburban gardens at fruiting times to the same well out onto the coastal plain. trees. Once a feeding site had On several occasions small flocks been located, birds flying in were (up to 14) were tracked from a quickly able to sight other vehicle as they left the edge of neighbouring trees and thus the Darling Scarp east of Gosnells slowly expand their foraging at 06:30–07:00 hrs to Welshpool zone. The birds showed persist- where they began to descend ence in returning to the same into gardens at Welshpool and food trees every day until the Belmont a distance of 16 km. trees were completely depleted They remained and fed at that of fruits before moving on. site until 16:30–18:30 hrs then Judging from our observations of flew back towards the Gosnells flocks foraging daily in the hills. This behaviour was Jarrah-Marri forest of the Perth observed for several weeks in Hills region, about 50% of birds August–September in that area from the western edge of the until all green and yellow fruits escarpment, i.e. from edge to on the trees were eaten. This about 3 km east, are involved in daily routine has become com- this movement onto the coastal monplace for numbers of birds plain, but the bulk of birds from in the northern forest block and areas further east in the Darling has continued year after year Range remain and forage within since 2000 and now extending the Jarrah-Marri forest. A across the entire Perth metro- number of birds banded in the politan area to forage on fruiting Perth Hills have been recorded Cape Lilac.

205 Jarrah-Marri forest

Records

Jarrah-Marri forest

Records

Figure 7. Records indicating slow foraging expansion on to the Swan Coastal Plain in 1994, and from 1994–2005, 1994–2011 and 1994–2016.

206 Jarrah-Marri forest

Records

Jarrah-Marri forest

Records

Figure 7 (cont.)

207 In areas where they found other PE tube erected in an exotic pine foods both native and exotic and tree (naso favour Marri as nest in some cases suitable roost sites trees) in a busy university car- with suitable drinking sites, new park is remarkable and provides roosts were established. In the some important insights into April 2016 Great Cocky Count conservation management. for example a total of 771 birds Numbers fluctuate at these sites were recorded at 29 roosts on the no doubt depending on the Swan Coastal Plain. These in- availability of food so monitor- cluded counts of 125 at Murdoch, ing breeding times and success 88 at Byford, 73 at Munster, 57 at would provide valuable inform- Coolbellup, 49 at Floreat, 42 at ation on the viability of this Kensington, 36 at Morley, 31 at population. Gosnells, 31 at The Vines, 26 at At other sites in the south-west, Darling Downs, 24 at Baldivis birds were first recorded feeding and 16 at Parklands. There is on Cape Lilac near Boddington considerable variation in num- in April 2003, at Serpentine and bers at some of these roosts. For Mundijong in February 2005 and example a total of 199 birds was at Dwellingup and Waroona in recorded at the Murdoch roost in March 2006 and a small flock 2014, 33 in 2015 and 125 in 2016; was recorded feeding on Cape also 47 at one Yokine roost in 2014, 28 in 2015 and none in 2016. This highlights the fact that there is considerable movement of birds to and from these roosts on the Swan Coastal Plain as well as a movement of flocks each day from the hills region onto the coastal plain. Following the establishment of roost sites on the coastal plain birds at two sites, Murdoch University and Perry Lakes, began prospecting for breeding hollows and in July 2011 and September 2012 at least two pairs bred successfully in artificial PE tube nest hollows erected at Murdoch (Figure 8). This was extraordinary as a few years previous (2000) there were no birds at all on that part of the Figure 8. Female at a PE Cockatube® Swan Coastal Plain. The fact that mounted in pine tree, Murdoch these birds bred in an artificial University.

208 Lilac at Harvey in May-June 2016. growing in towns such as Collie, The April 2003 record from near Brunswick Junction, Boyanup, Boddington is of great interest Bunbury, Whicher Range area, because it was not until March Donnybrook and Capel. Exten- 2006 that birds began to feed on sive groves of Cape Lilac along Cape Lilac at a regular Waroona laneways in the Tutunup area observation site (58 km to west) also have no evidence that birds and it is 80 km to the nearest are currently using this food northern record at Bedfordale. resource. This suggests that there is some movement of birds through the Southern Region: Byford- forest. Waroona-Harvey There is obviously some inter- Between May and November action and movement of small 2015 we carried out a series of numbers of birds from the Perth mostly east-west transects on the Hills to areas further south as southern Swan Coastal Plain some of the flocks in these more between Byford and Harvey to southern areas have discovered determine habitat use by Forest and learned to feed on Cape Red-tailed Black Cockatoos in Lilac. The recent records of birds roadside verges. These targeted feeding on Cape Lilac from surveys were to search for Harvey suggest that there has evidence of feeding, both old been some interaction of birds and recent, to determine if there along the escarpment between was a change in the status of Waroona and Harvey in recent birds during different times of times. We doubt that this dis- the year. There was a very covery and learnt behaviour extensive flowering of Marri would have been done inde- () in 2014–15 pendently but more likely resulting in a massive nut crop introduced to these southern on many trees especially those in flocks by contact with birds road verges in this part of the from further north. Probably Swan Coastal Plain. Between May because of the overall sedentary and August 2015 there was very nature of these populations the little evidence of recent foraging expansion or southward-spread and indeed few sightings of birds into new territory appears to within the region. This was in have been very slow and part of stark contrast to surveys in this may be due to the des- September–October 2015 where truction and fragmentation of there was extensive evidence of original habitat on the Swan birds foraging within that region Coastal Plain. (Figure 9). While there were still Certainly south of Harvey, birds some birds observed foraging still have not yet discovered within the adjacent hills Jarrah- Cape Lilac as a food source Marri forest there was obviously despite large numbers of trees considerable movement of birds

209 Figure 9. Surveys showing foraging of Marri seed on the Swan Coastal Plain, May–August 2015 (above) and September–October 2015 (facing page). from the hills onto the coastal ecology of some populations. plain to take advantage of the Unfortunately a great deal of extensive nutting of the Marri in road verge habitat was destroyed these road verges. As with Cape around Waroona, Yarloop, Lilac further north this appears Harvey and Lake Clifton in the to be a change in the foraging January 2016 wildfire. With a

210 Figure 9 (cont.) perimeter of 398 km this fire for these birds is vehicle strikes. In destroyed a total of 69,000 ha. August-September 2009 a total of 10 birds including adults and MORTALITY immatures were killed at a drinking site in a truck bay at the Vehicle Strikes edge of Albany Highway in One of the main mortality factors Bedfordale (probably more killed

211 but not found) and this would Wungong catchment were des- have had a significant impact on troyed during a controlled that small local population. “biodiversity management burn” The movement of birds onto the and it was noteworthy that these Swan Coastal Plain, especially trees burnt from the top down around Perth, has greatly in- indicating a fairly intense fire. creased the risk of birds being The January 2016 Waroona- killed or injured from vehicle Yarloop wildfire had a deva- strikes. Records from Kaarakin stating impact on the flora and (Black Cockatoo Conservation fauna of the area. The fire burnt Centre) for example show that 11 an estimated 69,000 ha including birds were brought in dead or extensive areas of Jarrah-Marri injured in January 2016; four in forest and road verges. This fire February; five in March; seven in was extremely intense with the April; and eleven in May. Also entire canopy, understorey and three birds were recorded as ground layers being burnt being killed or injured after (Figure 10). The loss of about 80– being hit by a train at Serpentine. 90% of foraging habitat for the small resident flocks in that region means that these birds Fire would have needed to forage The loss of nest trees through well outside their normal home logging, fire (including pre- range to survive. The two re- scribed burns) and post-fire clean sources most likely to limit their up, and weather is of concern, continual survival in the area are especially fire. Fire is acknowl- in the short term, the food edged as a significant factor in the supply and in the longer term, fall of hollow trees (Parnaby et al. nest hollows. 2010). Many veteran and stag Marri Overall this fire was an ex- (the favoured nest tree) are tremely significant ecological particularly susceptible to fire. event in that region and we plan Most of these trees have only an to monitor the response of black outer living shell around rotten cockatoos to determine where heartwood. A fire at the base of these populations forage and these trees quickly burns through adapt to change after the burn. the outer shell creating a chimney Five months after the fire and stack that destroys the tree. the widespread presence of basal The January 2005 Perth Hills fire reshooting and fresh ground for example, destroyed four out growth suggests that some areas of five known nest trees with of both forest and verge were hollows leaving only a burnt regenerating rapidly. Neverthe- stump or the tree completely less, there will be a gap in the burnt to ground. available food supply chain In May 2011 another three out of causing them to forage else- five known nest trees in the where. The loss of many large

212 Figure 10. Loss of habitat at Lake Clifton January 2016 (top) and Waroona 2016 (bottom) post-wildfire. veteran Marri that are required The same January 2016 Waroona for breeding hollows, and which wildfire also swept through the are already scarce in the land- nearby Larego forest block and scape, is concerning. Moderate destroyed a total of 19 of 41 fires often help create large known cockatoo hollows. hollows suitable for cockatoos in old trees, however, wildfires tend to destroy all old or veteran trees Nest Tree loss that could provide future During our study we have hollows. noticed a fairly high fall rate

213 (including trees blown over Ravens during storms) of veteran and Movement onto the Swan stag Marri (Johnstone et al. 2013a) Coastal Plain has also brought e.g. on 23 November 1999 a nest these cockatoos into greater tree we had been monitoring, in contact with Australian Ravens which there was a large chick, (Corvus coronoides) that harass blew over in strong easterlies; the and sometimes kill juveniles and chick that was almost ready to immatures (Figure 11). Attacks fledge was killed (WA Museum and harassment by ravens often specimen A36732). leads to the young cockatoos being separated from their adults Feral bees and being mobbed. Not always About 26% of known breeding do the ravens succeed and, on hollows of Forest Red-tailed one occasion, a raven that was Black Cockatoo in our study sites attacking and holding tail have been taken over by feral feathers of a fledgling Red-tailed European Honey Bees (Apis Black Cockatoo, in a tree, had mellifera) and at some sites at the one of its legs bitten off by an edge of the Darling escarpment adult male Red-tail Black (Bedfordale, Serpentine) it is as Cockatoo that was following high as 50%. At one nest hollow close behind. Ravens have great- in Bedfordale in December 2000, ly increased in abundance in the a chick that appeared healthy Perth region since the late 1960s may have succumbed to swarm- and are now common through- ing bees in the same tree near the out the suburbs and are attracted hollow entrance. to road-killed animals, garbage

Figure 11. Red-tailed Black Cockatoo being attacked by an Australian Raven, Bedfordale.

214 Marri Corymbia calophylla Silver Princess Eucalyptus caesia

Illyarrie Eucalyptus erythrocorys Sheoak Allocasuarina sp.

Jarrah Eucalyptus marginata Cape Lilac Melia azedarach

Figure 12. Some common foods (native and introduced) on the Swan Coastal Plain.

215 dumps and spilt food in parks Dongara region of Western Aus- and around food take-away tralia and commonly grown in outlets. Perth gardens; Bushy Yate (Eucalyptus lehmannii) endemic to the south-west of Western Aus- DIET tralia (mainly Albany and Principal native food species Esperance Plain) and used as a The principal foods (Figure 12) of street tree in Perth and Kaffir the Forest Red-tailed Black Plum (Harpephyllum caffrum) a Cockatoo in the northern Jarrah- native of southern Africa and Marri forest and the Perth grown in Perth gardens and used Region are the seeds of Marri as a street tree. Also of interest (Corymbia calophylla) and Jarrah recently was a flock of 12 birds (Eucalyptus marginata) and their feeding on olives Olea europaea in method of feeding on these Shenton Park. fruits is distinctive (see Johnstone and Kirkby 1999). Other less important foods IMPLICATIONS FOR THE include Blackbutt (Eucalyptus FUTURE patens), Sheoak (Allocasuarina The past half century has seen fraseriana), Snottygobble massive environmental change ( longifolia), spp. in the south-west of Western including H. petiolaris, Tuart Australia. The region is now a (Eucalyptus gomphocephala) and severely fragmented landscape Red Heart or Moit (E. decipiens). and the future loss of habitat, the changing structure of the Introduced food species Jarrah-Marri forest through Some introduced species regu- forestry and fire, the impact of larly foraged include the Cape introduced and invasive species Lilac (Melia azedarach); Spotted and the effects of climate change Gum (Corymbia maculata) a make the survival of the Forest native of eastern Australia Red-tailed Black Cockatoo and (Queensland, NSW and Victoria) indeed its forest relative Baudin’s and commonly grown in the Cockatoo (Calyptorhynchus Perth region; Lemon-scented baudinii) of great concern. As Gum (C. citriodora) originally Jarrah and Marri availability from Queensland, but natural- becomes increasingly threatened ised in the Darling Range and in in the face of habitat modi- suburban Perth; Silver Princess fication, climate change and fire, (Eucalyptus caesia) endemic to the Forest Red-tailed Black central wheatbelt region of Cockatoos may become more Western Australia, but common dependent on some introduced in Perth gardens; Illyarrie species for food in some areas. (Eucalyptus erythrocorys) endemic The change in foraging be- to the limestone ridges of the haviour by Forest Red-tailed

216 Black Cockatoos suggests op- for project support and the portunism, but could also be Department of Housing for possibly linked or have been financial assistance for this evoked by a decline in the project and to Vicki Stokes availability or nature of Jarrah (Alcoa) for information about and Marri as food in some parts the Larego forest block. We also of the Darling Range due to thank Margaret Owen for declining rainfall. The big observations at roost sites at downside of this movement of UWA Sports Park, Brockway birds onto the Swan Coastal Road, and Peter Mawson (Perth Plain has been the additional Zoo), Rick Dawson (Department impact of mortality with many of Parks and Wildlife) and Louise deaths from collisions with Hopper (Kaarakin Conservation motor vehicles and this loss is Centre) for banding data and not sustainable. Furthermore the information on bird mortality. altered foraging behaviour has led to local changes in distri- bution and roosting patterns REFERENCES that will no doubt also influence ABBOTT, I. and BARRETT, G 2016. breeding success. While Forest Suburban occurrence of birds: A Red-tailed Black Cockatoos feed microgeographic perspective their fledglings on Cape Lilac based on comparison of two sites seed, it may not be a suitable in inner suburbs of Perth. Western food to stimulate and sustain the Australian Naturalist 30(3): 152–171. next breeding cycle. Further studies are required on the ALEXANDER, W.B. 1921. The Birds availability of different food of the Swan River district, West- resources in different years ern Australia. Emu, 20: 149–168. which may help determine what Cockatoo Care programme. URL: triggers important breeding http://www.cockatoocare.com events. [accessed May 2016]. W.A. Museum In 2016, almost no Forest Red- Perth and formerly Water tailed Black Cockatoos were Corporation of W.A. recorded breeding at any of our DEC 2008. Forest Black Cockatoo study sites and no juveniles (Baudin’s Cockatoo (birds of the year) were recorded Calyptorhynchus baudinii and in the northern Jarrah forest or Forest Red-tailed Black Cockatoo on the Swan Coastal Plain. This Calyptorhynchus banksii naso) indicates that this population recovery plan 2007–2016. Wildlife may be at greater risk that we Management Program No. 42. originally thought. Department of Conservation and Land Management, Perth. GARNETT, S.T. and CROWLEY, ACKNOWLEDGEMENTS G.M. 2000. The Action Plan for We thank 360 Environmental Australian Birds 2000. Environ-

217 ment Australia and Birds Aus- JOHNSTONE, R.E. and KIRKBY, T. tralia, Canberra. 2009. Birds of Bungendore Park, GOULD, J. 1865. Handbook to the Bungendore Park Management Birds of Australia, London. Committee, Armadale. JOHNSTONE, R.E. and STORR, JOHNSTONE, R.E., KIRKBY, T. and G.M. 1998. Handbook of Western SARTI, K. 2010. Cockatoos Calling. Australian Birds, Volume 1, non- pp. 3–9 In Endangered Black passerines (Emu to Dollarbird). Cockatoos in Western Australia: Western Australian Museum, Proceedings of a symposium about Perth. their biology, status, threats and JOHNSTONE, R.E. and KIRKBY, T efforts to restore their habitat and 1999. Food of the Forest Red-tailed populations. Urban Bushland Black Cockatoo Calyptorhynchus Council WA (Inc.), Perth. banksii naso in south-west Western JOHNSTONE, R.E., KIRKBY, T. and Australia. Western Australian SARTI, K. 2013a. The breeding Naturalist 22(3): 167–177. biology of the Forest Red-tailed JOHNSTONE, R.E. and KIRKBY, T Black Cockatoo Calyptorhynchus 2005. ‘Cockatoo Care’ – A Public banksii naso Gould in south- Programme. Western Wildlife Vol. western Australia. I. Charac- 9. (4). teristics of nest trees and nest hollows. Pacific Conservation JOHNSTONE, R.E. 2006. Going, Biology 19(3): 121–142. going, gone! Veteran and stag trees: a valuable resource. Western JOHNSTONE, R.E., KIRKBY, T. and Wildlife Vol. 10. (1). SARTI, K. 2013b. The breeding JOHNSTONE, R.E. and KIRKBY, T biology of the Forest Red-tailed 2006. Cockatoos in Crisis. Black Cockatoo Calyptorhynchus Landscope, 21 (2). banksii naso Gould in south- western Australia. II. Breeding JOHNSTONE, R.E. and KIRKBY, T Behaviour and diet. Pacific 2007. Feral European honey bees: a Conservation Biology 19(3): 143–156. major threat to cockatoos and other tree hollow users. Western MABBERLEY, D. J. and PANNELL, Australian Naturalist 25(4): 252– C. M. 2013. Melia. 254. 26: 11–13. CSIRO Publishing, Melbourne. JOHNSTONE, R.E. & C. and KIRKBY, T. 2008. White-tailed MAWSON, P. and JOHNSTONE, Black Cockatoos on the Northern R.E. 1997.Conservation status of Swan Coastal Plain (Lancelin– parrots and cockatoos in Western Perth) Western Australia. Report Australia. Eclectus, 3: 21–23. June 2008 for DEWHA. PARNABY, H., LUNNEY, D., JOHNSTONE, R.E. and KIRKBY, T. SHANNON, I. and FLEMING, M. 2009. Birds of the Wungong Dam 2010. Collapse rates of hollow- Catchment, Bedfordale, Western bearing trees following low Australia. Western Australian intensity prescription burns in Naturalist 26(4): 219–274. the Pilliga forests, New South

218 Wales. Pacific Conservation Biology SAUNDERS, D.A., ROWLEY, I. and 16(3): 209–220. SMITH, G.T. 1985. The effects of PECK, A., BARRETT, G. and clearing for agriculture on the WILLIAMS, M. 2016. The 2016 distribution of cockatoos in the Great Cocky Count: a southwest of Western Australia, community-based survey for In Birds of Eucalypt Forests and Carnaby's Black-Cockatoo Woodlands: Ecology, Conservation, (Calyptorhynchus latirostris) and Management. Eds A. Keast, H.F. Forest Red-tailed Black-Cockatoo Recher, H. Ford, D. Saunders, pp. (Calyptorhynchus banksii naso). 309–321. Royal Australasian Birdlife Australia, Floreat, Ornithologists Union and Surrey Western Australia. Beatty: Sydney. ROBINSON, A. 1960. The import- SERVENTY, D.L. 1948. The birds of ance of the Marri as a food source the Swan River district, Western to south-western Australian Birds. Australia. Emu, 47: 241–286. Western Australian Naturalist 7(5): STRANGER, R. 2003. The Birds of 109–115. the Mandurah District, Western ROBINSON, A. 1970. Department Australia. Fineline Print. of Fisheries and Fauna. Fauna STORR, G.M. and JOHNSTONE, Bulletin. 4(1): 20. R.E. 1988. Birds of the Swan Coastal Plain and adjacent seas and islands. Records of the Western Australian Museum, Supplement No. 28: 1–76.

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