Cockatoo Calyptorhynchus Research Articles

Clutch size, incubation and nestling periods, and age estimation of nestling Red-tailed Black Cockatoos Calyptorhynchus banksii escondidus in the Western Australian wheatbelt

ABSTRACT The breeding ecology of the Red-tailed Black Cockatoo Calyptorhynchus banksii escondidus was studied in the northern wheatbelt of Western Australia from the austral spring of 1974 to the end of 1981. The usual clutch was one egg, but 8 of 465 clutches were of two eggs, none of which produced two fledglings. The incubation period was 29 days, similar to that of other species of black cockatoo with similar body mass. The nestling period was 80-84 days, nearly 17% longer than the similarly-sized Carnaby's Cockatoo C. latirostris. The ages of nestling Red-tailed Black Cockatoos may be estimated by comparison with photographs taken of nestlings of known age or estimated more precisely from the length of the nestling's folded wing. Aging nestlings enables the calculation of laying and hatching dates.

Managing a breeding population of endangered Carnaby’s Black–Cockatoo Calyptorhynchus latirostris on the edge of their range

Context The Carnaby’s Black–Cockatoo Calyptorhynchus latirostris, an endangered species endemic to south-west Western Australia, has experienced a 30% contraction in range and 50% decline in population since the 1940s. A breeding population of Carnaby’s Black–Cockatoo was first described at Murchison House Station in the 1970s, but breeding had not been recorded there since the 1990s. Aims We sought to confirm whether Carnaby’s Black–Cockatoos were still breeding at this location at the far-northern edge of their range, hundreds of kilometres from the nearest known breeding site. Once confirmed, we compared population, hollow and nestling characteristics with those of other well-studied breeding populations of the same species and surveyed foraging and nesting habitat to evaluate population health and inform management. Methods We monitored 30 breeding attempts and characterised 21 confirmed hollows. We conducted comprehensive vegetation community surveys at nine sites. Key results We confirm that Carnaby’s Black–Cockatoos are still breeding at the far-northern edge of their range. Hollow and nestling characteristics are similar to breeding populations elsewhere. We found no evidence of plant recruitment for crucial foraging or nesting species. Conclusions The absence of plant recruitment in both foraging and nesting habitats suggests that active management will be required to support ongoing breeding. We recommend conserving and revegetating foraging and breeding habitat, maintaining hollows and/or providing artificial hollows while trees regenerate. Implications Foraging and breeding habitat will need long-term management to support ongoing breeding of this threatened species at the northern edge of its range.

Food and movements of the Red-tailed Black Cockatoo Calyptorhynchus banksi escondidus in the Western Australian wheatbelt

ABSTRACT The diet and movements of a breeding population of the Red-tailed Black Cockatoo Calyptorhynchus banksi escondidus was studied between spring 1974 and the end of 1981 at Nereeno Hill in the northern wheatbelt of Western Australian. The birds fed almost exclusively on the seed of Double Gee Emex australis, an introduced, prolific, agricultural weed. When incubating and raising young nestlings, parents foraged within 5 km of their breeding area. However, once their nestlings were older, they often foraged more than 20 km from their nest hollows, commuting over an hour in the early morning and again in the evening. In doing so, they passed over available food, to join large, non-breeding, foraging flocks. Once the birds finished breeding they foraged widely in large flocks of over 1000 birds, up to 200 km from their breeding area. The dependence on the seed of an agricultural weed for food has allowed the birds to increase their distribution and abundance, but is a potential threat to the cockatoos, as any control measure that severely reduces the density of Double Gee may adversely impact on the distribution of the cockatoos in the southern part of their range.

The influence of surrounding habitat, behaviour and interspecific competition on nestbox use by endangered Glossy Black Cockatoos (Calyptorhynchus lathami halmaturinus)

Nestboxes have been deployed for parrots and cockatoos (Psittaciformes) worldwide, but there is limited evidence of their efficacy for these species. We examined the use of nestboxes by endangered South Australian Glossy Black Cockatoos Calyptorhynchus lathami halmaturinus, a habitat specialist that feeds almost solely on the seeds of Drooping Sheoak Allocasuarina verticillata trees, and investigated the factors that influenced nestbox use. Between 1998 and 2017, the mean annual proportion of nesting attempts that successfully fledged a chick was similar in nestboxes (52%, n = 547) and natural hollows (53%, n = 627). Nestbox use increased over time, which may reflect changes in the size and extent of the Glossy Black Cockatoo population over the study period. Nestboxes were more likely to be used by Glossy Black Cockatoos if they were close to the nest of another breeding pair and were not occupied by Yellow‐tailed Black Cockatoos Zanda funerea early in the breeding season. Nestboxes were also more likely to be used if they had been used in the previous breeding season, indicating nest‐site fidelity. The amount of A. verticillata feeding habitat in a 1‐km and 5‐km radius did not significantly influence nestbox use. Our study provides further evidence of the value of nestboxes to cockatoo conservation programmes, but also suggests that multiple factors other than local food availability influence uptake by a target species. Given that Glossy Black Cockatoos prefer to aggregate their nests, nestboxes for this species are most likely to be beneficial when they are used to expand the capacity of existing breeding areas or are clustered in the landscape. Our study demonstrates that well‐designed nestbox deployments should consider the preferred social groupings of cockatoos during the breeding season, and the location of competitor species, in order to maximize nestbox uptake.

Horner Syndrome With Ipsilateral Wing Paresis in a Wild, Juvenile Yellow-Tailed Black Cockatoo (Calyptorhynchus funereus)

A juvenile yellow-tailed black cockatoo (Calyptorhynchus funereus) was presented with paresis of the right wing, ptosis, and miosis of the right eye; feather erection of the right side of the head and neck; and a penetrating injury over the right pectoral muscle. Temporary reversal of ptosis, miosis, and feather erection after administration of phenylephrine drops confirmed a diagnosis of Horner syndrome. Computed tomographic imaging revealed a fractured rib, traumatic lung lesions, and subcutaneous emphysema. The right-sided Horner syndrome and wing paresis were attributed to a sympathetic nerve trauma of the eye and feathers and to the brachial plexus, respectively. This report describes the diagnosis and resolution of ptosis and miosis within 8 weeks and recovery of feather symmetry and wing function within 11 weeks of the cockatoo's initial presentation with a conservative-management treatment plan.

Artificial hollows provide an effective short-term solution to the loss of natural nesting hollows for Carnaby's Cockatoo Calyptorhynchus latirostris

The ecology of one breeding population of Carnaby's Cockatoo Calyptorhynchus latirostris has been studied at Coomallo Creek, Western Australia, since 1969. A wildfire destroyed breeding habitat in part of the study area and adjoining areas in late December 2009. An increase in the number of breeding attempts the following year suggested that hollows were probably limiting. From 2011, the number of hollows available to the cockatoos was increased by repairing derelict natural hollows and providing artificial hollows. By 2017, cockatoos had access to 87 natural and 68 artificial hollows the approximate dimensions of natural hollows. Artificial hollows were readily accepted, however there were significant differences in the probability of hollows being used due to location and land use type. Despite floor temperatures of black and white artificial hollows being warmer than those of natural hollows, there were no significant differences in the probability of hollow use, the probability of breeding failures, and nestling condition in either white or black artificial hollows or natural hollows. The number of breeding attempts rose from 52 in 2011 to 127 in 2016 indicating that management intervention was effective. Between 2011 and 2018, artificial hollows provided 45% of available hollows and 54% of breeding attempts were made in them. By 2018, the number of breeding attempts in the area was 112% higher than in 2011. Artificial hollows provide an excellent short-term solution to the continuing loss of natural hollows. However, without extensive re-establishment of breeding and foraging habitat, the future for Carnaby's Cockatoo is uncertain.

First records of nesting by South Australian Glossy Black- Cockatoos Calyptorhynchus lathami halmaturinus on eastern Kangaroo Island

The South Australian Glossy Black-Cockatoo Calyptorhynchus lathami halmaturinus is extinct on mainland Australia, and occurs only on Kangaroo Island. Between 1995 and 2016, a successful long-term Recovery Program more than doubled the population of this taxon on Kangaroo Island. This paper documents the first records of nesting by Glossy Black-Cockatoos on the Dudley Peninsula on eastern Kangaroo Island in 2015 and 2018, at a time when flock size had increased to 35 individuals in post-breeding counts on the Dudley Peninsula. Nesting there is evidence of the growth and expansion of the Glossy Black-Cockatoo population over the past 25 years, which is likely a result of conservation efforts. This new eastern nesting site expands the breeding range of this subspecies ~13 km east, and to the part of Kangaroo Island that is closest to mainland South Australia.

Implications of Banksia seed reward for conservation and management of Carnaby’s cockatoo on the Swan coastal plain, Western Australia

The food resource utilisation of six species of Banksia by the endangered Carnaby’s cockatoo (Calyptorhynchus latirostris) was investigated on the Swan coastal plain, Western Australia, over a 12-month period. The energy yield from the seeds harvested by the cockatoos was determined and the information was combined with data on the number of infructescences produced per hectare, the average seed yield per infructescence and the average rate of harvest of that species of seed by the cockatoos to calculate estimates of the number of infructescences required to support a single cockatoo per day under a range of scenarios. Over 65% of infructescences of each species of Banksia handled by the cockatoos were consumed for seed. Banksia sessilis had the largest number of infructescences and follicles manipulated by Carnaby’s cockatoos. The energy content of Banksia seed was 20–23 kJ g–1. Seed weight varied from 0.075 ± 0.016 (s.e.) g for B. attenuata to 0.007 ± 0.002 (s.e.) g for B. sessilis. The number of infructescences required to meet the birds’ daily energy intake ranged from 14 for B. grandis to 3821 for B. sessilis. The results have important implications for the continued capacity of the Swan coastal plain to support Carnaby’s cockatoos, for the future survival of obligate seeding Banksia spp. and for anthropogenic revegetation programs utilising Banksia spp.

Culling farm wildlife for conservation and production on “Koobabbie”, a cereal and sheep growing property, in the northern wheatbelt of Western Australia

ABSTRACT Koobabbie is a 7,173ha cereal and sheep growing property in the northern wheatbelt of Western Australia. Unlike most wheatbelt properties that have been extensively cleared of native vegetation, Koobabbie retains 41% of its area under native vegetation. It is listed as an important bird area by BirdLife Australia and BirdLife International, and is a significant part of the region's conservation estate. Half of Australia's cockatoo species occur on the property, including the endangered Carnaby's Cockatoo Calyptorhynchus latirostris. The Major Mitchell's Cockatoo Cacatua leadbeateri occurs in small numbers on the property, while the Galah C. roseicapilla and Western Corella C. pastinator occur in large numbers, and compete with Carnaby's Cockatoo and Major Mitchell's Cockatoo for nest hollows. The owners have been culling Galah and Western Corella since 1997 to reduce competition for nest hollows. In addition, several other species of native animal, and three species of introduced mammal are culle...

Cumulative learnings and conservation implications of a long-term study of the endangered Carnaby's Cockatoo Calyptorhynchus latirostris

ABSTRACT The endangered Western Australian endemic Carnaby's Cockatoo Calyptorhynchus latirostris was studied by Denis Saunders from 1968 to 1996, and by Rick Dawson and Denis Saunders from 2009 to...

Assessing the spatial ecology and resource use of a mobile and endangered species in an urbanized landscape using satellite telemetry and DNA faecal metabarcoding

The conservation of highly mobile species presents challenges to managers for assessment of threats to survival, given the difficulties in locating and observing such species. Here we evaluate satellite telemetry, DNA faecal metabarcoding and traditional field observations as three complementary techniques to acquire critical management information for an endangered species, Carnaby's Cockatoo Calyptorhynchus latirostris. Satellite telemetry of 23 birds resulted in 6026 location fixes accurate to within 500 m, and combined with extensive field observations and DNA faecal metabarcoding resulted in a more detailed understanding of how this species survives in an urbanized landscape. We identified 168 night roosts, 75% of which were previously unknown, which will contribute towards a more accurate population size estimate based on annual counts of roosting birds. We also determined the scale of daily movements (morning 5.4 ± 3.4 km from roost, afternoon 5.5 ± 3.3 km to roost; maximum distance between consecutive roosts 69.7 km) and the size of foraging areas around roosts (range 17–276 km2), and identified dependence on a variety of native and exotic food sources. Field observations identified 11 food‐plant families, but combined with DNA faecal metabarcoding this was extended to 21 food‐plant families. The three techniques were compared to assess their individual and collective values. By combining spatial ecology information from satellite telemetry with ecological knowledge from field observation and DNA faecal analysis, we gained deeper insights into the ecology of the species than would have been possible from any one technique alone. This information will lead to more strategic conservation planning to allow this species to persist within a rapidly expanding urban environment.

Identification of individual Carnaby's Cockatoos Calyptorhynchus latirostris from distinctive plumage markings

This study determined methods for identifying individual Carnaby's Cockatoo Calyptorhynchus latirostris using natural variations in markings, to assist future research and management. Photographs of wild and captive cockatoos and museum specimens were studied and a variety of useful identification characteristics were found. These included marks on subterminal tail panels, yellowish colouration, upper mandible markings, atypical white feathers, white panels on undertail coverts and grey areas in the ear covert patches of females. A combination of distinctive marks could sometimes be used to identify individuals. Distinctive markings may be short term and useful until the next moult, or longer term and maintained over years. Females provided more identifying marks than males, with 28.6% of preserved adult female tails having black spots and/or bars in their white tail panels compared to 5.0% of adult males, and 53.1% of immature females compared to 12.5% of immature males. The tails of immature C. latirost...

Nature conservation on agricultural land: a case study of the endangered Carnaby’s Cockatoo Calyptorhynchus latirostris breeding at Koobabbie in the northern wheatbelt of Western Australia

Nature conservation and agricultural production may be considered as conflicting objectives, but for a wheat and sheep property in Western Australia they have been pivotal management objectives for the last 48 years. Koobabbie, a 7,173 ha property, has retained 41.5% of the original native vegetation, and is a designated Important Bird Area by BirdLife Australia, while still being an economically profitable agricultural enterprise. Since 1987 the owners of Koobabbie have kept detailed records of the avifauna of the property, and encouraged staff from government, non-government and academic organisations to conduct research and monitoring of the endangered Carnaby’s Cockatoo Calyptorhynchus latirostris breeding on their property. In addition, they have instituted control programs for two over-abundant cockatoo species which compete with Carnaby’s Cockatoo for nest sites, and for Feral Cats that are predators of nesting female Carnaby’s Cockatoo and their offspring. This paper presents the results of research and monitoring from 2003-2013, during which seven artificial nesting hollows were erected, and former active nest hollows that had become derelict were repaired. By 2008, the number of breeding pairs on the property was at least 27, but two mass deaths of breeding females in 2009 and 2012 reduced the number of breeding pairs by 80%. This study illustrates the importance of monitoring conservation on private property, and raises a number of issues in relation to management of endangered species dependent on large hollow-bearing trees on private property.

Use of tree hollows by Carnaby’s Cockatoo and the fate of large hollow-bearing trees at Coomallo Creek, Western Australia 1969–2013

Abstract The loss of hollow-bearing trees and lack of replacements are important issues throughout the world where development of intensive agriculture has resulted in the reduction and fragmentation of natural woodlands. Many species of animal depend on hollows (cavities) for breeding and shelter, and are impacted by these changes. One such species is the endangered Carnaby’s Cockatoo Calyptorhynchus latirostris , an endemic of southwestern Australia, which nests in large hollows in eucalypt trees. Nest hollow selection by a breeding population at Coomallo Creek, in the wheatbelt of Western Australia, was studied from 1969 to 2013. The cockatoos nested in any hollow large enough to access (mean entrance diameter 270 mm, floor diameter 407 mm and depth 1.24 m). Nesting attempts in shallow hollows ( 1000 mm). Breeding females returned to the same hollow they used previously, provided they had been successful in the previous breeding attempt and the hollow was not occupied. During the study, the cockatoos used 252 large hollow-bearing trees. By 2013 40% of these had fallen or been pushed over, had been burnt deliberately or by wildfire, or had been damaged such that they were no longer suitable for use by the cockatoos; an average annual loss rate of 0.91%. Based on this rate of loss, only 29% of large hollow-bearing trees standing in 2013 will be extant in 2125 and not all of these can be expected to offer useable nest hollows. The conservation implications arising from the results of the study are discussed.

The breeding biology of the Forest Red-tailed Black Cockatoo Calyptorhynchus banksii naso Gould in south-western Australia. I. Characteristics of nest trees and nest hollows.

The Forest Red-tailed Black Cockatoo Calyptorhynchus banksii naso (FRTBC) is a large, iconic forest cockatoo, endemic to the south-west corner of Western Australia. It is currently listed as Vulnerable under the State Western Australian Wildlife Conservation Act and under the Commonwealth Environment Protection and Biodiversity Conservation Act. In this paper, we provide details of nest tree and nest hollow requirements based on details of hollows in 128 nest trees studied over 17 years. FRTBC are monogamous and pairs nest in tree hollows from 6.5–33 m above ground. Most nests are in very large and very old, mature Marri Corymbia calophylla, a long-lived endemic tree species, which is the most important nesting tree throughout the FRTBC range. Nest trees of all species had a mean circumference at breast height of 2.79 m, a mean estimated age of 222 years and a mean overall height of 20.24 m. Marri nest trees had an mean circumference at breast height of 2.76 m, a mean estimated age of 220 years (95% confidence limit 209–231 years) and an average overall height of 20.04 m. The rate of fall or loss of nest trees was high, c. 16.6% per decade. A wide range of hollow types, defined by position of the hollow in the tree, were found. Hollow aspects were also diverse. The mean height to a hollow was 14.49 m. Mean hollow depth was 1.44 m, mean floor space (the longest linear distance across the bottom of the hollow) was 33.2 cm and the mean hollow entrance area was 30 x 34 cm. FRTBC nests are typically, but not always, clustered in the landscape and social interactions within the flock are likely to play a part in the clustering of nests. Nest competitors, including feral European Honey Bee Apis mellifera, Carnaby’s Cockatoo Calyptorhynchus latirostris, Baudin’s Cockatoo C. baudinii and the Regent Parrot Polytelis anthopeplus were recorded using nest hollows once used by FRTBC. In the past Marri was harvested commercially, especially the largest and oldest trees, for timber and woodchips. In recent times the volume of Marri logs has been reduced due to a decline in markets e.g. between 2004 and 2010 a total of 95,436 m³ was harvested (K. Whitford, pers. comm.). Given the importance of large, old trees for FRTBC breeding habitat, conservation of these trees

Ecology of black cockatoos at a mine-site in the eastern jarrah-marri forest, western Australia.

Three threatened black cockatoos inhabit the Jarrah Eucalyptus marginata-Marri Corymbia calophylla forest of southwestern Australia: Baudin’s Cockatoo Calyptorhynchus baudinii, Carnaby’s Cockatoo C. latirostris, and Forest Redtailed Black Cockatoo C. banksii naso [FRTBC]. Their local ecology in relation to anthropogenic disturbance is poorly known, hampering effective conservation management. Therefore we studied their group size, site occupancy patterns, habitat use, and food plants at a mine-site and its surrounds in the eastern forest over three years. FRTBC showed similar group sizes and occupancy across seasons, suggesting year-round residency and no marked seasonality in movements and grouping patterns. In contrast, Carnaby’s Cockatoos were up to twice as abundant in spring and summer, indicating migrating or transient flocks and some year-round residents. Few Baudin’s Cockatoos were present in summer, but their abundance increased at other times. All three cockatoos were observed in modified or humanmade habitats such as mine-site rehabilitation, farm paddocks, and pine plantations. Carnaby’s Cockatoos used the broadest habitat range. We documented feeding on 16 plant species, with Carnaby’s Cockatoos eating at least 10. Examination of feeding residues as well as observations of behaviour were essential to obtain a complete picture of feeding. Current mine-site rehabilitation protocols provide food for all three black cockatoos within a decade and should continue to do so long-term if Marri is maintained in the seed mix. However, because climate change scenarios predict declining rainfall over much of southwestern Australia, the plant species used to revegetate mine-sites and other landscapes may need to be reconsidered. For areas that do not specify restoring a jarrah forest landscape, the selective use of exotic or non-endemic flora better adapted to lower rainfall conditions may be an option.

The impacts of Sambar Cervus unicolor on the threatened Shiny Nematolepis Nematolepis wilsonii

Shiny Nematolepis Nematolepis wilsonii is a small understorey tree endemic to Victoria, south east Australia. The species is listed as threatened due to its limited distribution and low abundance. The sole known population, of approximately 400 metres individuals, is located in the Yarra Ranges National Park, Victoria. Paired exclusion plots were erected to investigate the impact of antler rubbing and thrashing activities of Sambar Cervus unicolor on Shiny Nematolepis. Sambar rubbing activities removed, on average, over half the circumference of bark down to the cambium of mature trees. Rubbing damage covered a range of tree sizes, with rubbed individuals in significantly poorer health and exhibiting 19% less relative foliage cover than non-rubbed individuals. Saplings selected by Sambar for thrashing had a significantly greater stem diameter and were most commonly situated beside the road. Other forms of damage to Shiny Nematolepis included storm events and biting by Yellow-tailed Black Cockatoo Calyptorhynchus funereus, but Sambar pose an added threat, which is likely to result in further decline of this threatened population.

Update on Longevity and Movements of Carnaby?s Black Cockatoo

Carnaby's Black Cockatoo Calyptorhynchus latirostris is an endangered species, found only in the southwest of Western Australia. Between 1971 and 1976 this species was the subject of a detailed ecological study (Saunders 1982). As part of that study, adults and fledglings were individually marked on each wing with stainless steel tags (patagial tags) described by Rowley and Saunders (1980). They were also marked with a numbered leg band of stainless steel supplied by the Australian Bird Banding Scheme. Observations made of tagged individuals provided much of the data used to explain the breeding biology, behaviour and movements of this species (Saunders 1980, 1982, 1986; Saunders and Ingram 1998). Despite major problems associated with the use of patagial tags (Saunders 1988), much of the ecology of the species could not have been investigated without their use.

The status of cockatoos in south-west Western Australia and conservation efforts by Perth Zoo

There are eight indigenous species (with two represented by two subspecies) and one introduced species of cockatoo in south-west Western Australia. Woodland clearance for agriculture has contracted the range of at least five species and fragmented the natural habitat across the region. Perth Zoo, in collaboration with the state conservation authority, private aviculturists and community groups, has developed a series of co-operative breeding programmes and education initiatives to protect local species of cockatoo and prevent further decline of wild populations. Detailed descriptions are given of the breeding requirements and threats which affect four species, Carnaby's cockatoo Calyptorhynchus latirostris, Baudin's cockatoo Calyptorhynchus baudinii, forest Red-tailed black cockatoo Calyptorhyn chus banksii naso and the southern subspecies of the Western long-billed corella Cacatua pastinator pas-tinator, and the contribution that the husbandry, education and captive-breeding activities at Perth Zoo make to the conservation of the species is described.

A serologic survey for avian polyomavirus and Pacheco's disease virus in Australian cockatoos

Sera collected from wild and captive Australian cockatoos and other psittacine species (n = 411) were tested for antibodies to avian polyomavirus (APV) and Pacheco's disease virus (PDV). Of 144 wild sulphur‐crested cockatoos (Cacatua galerita) sampled at three regions in New South Wales (NSW) 96 (64.4%) birds had positive (≥ 1:32) neutralizing antibody titres to avian polyomavirus (range 1:32–1:2048). Two of 17 wild long‐billed corellas (Cacatua tenuirostris) were also APV‐antibody positive. However, no samples from 107 wild galahs (Eolophus roseicapillus) were positive for neutralizing antibody to APV. Sera were also collected from captive psittacine bird flocks from NSW, Tasmania, Victoria, and Western Australia. In a mixed aviary of cockatoos and lorikeets, APV antibody was detected in sera from sulphur‐crested cockatoos, Major Mitchell's cockatoos (Cacatua leadbeateri), a white‐tailed black cockatoo (Calyptorhynchus baudinii latirostris), a red‐tailed black cockatoo (Calyptorhynchus magnificus) a single galah, a rainbow lorikeet (Trichoglossus haematodus), and a scaley‐breasted lorikeet (Trichoglossus chlorolepidotus). All 411 wild and captive birds were negative for the presence of neutralizing antibody to PDV. These results indicate that wild sulphur‐crested cockatoos in NSW are enzootically infected with avian polyomavirus and that the sampled populations are free of Pacheco's disease.