Showing papers in "Emu in 2007"

Gibson Desert birds: responses to drought and plenty

Abstract: There is little information on the response of birds to rainfall in the Australian arid zone. Counts of birds between 1988 and 1992 on paired 1-km2 quadrats representing major landform and vegetation types in the Gibson Desert revealed significant changes in species richness, community composition and abundance during increasing drought and following drought-breaking high rainfall. Species considered sedentary or resident (sedentary—resident), which were insectivorous or carnivorous, declined in abundance as the drought progressed, with at least one species, Rufous-crowned Emu-wren (Stipiturus ruficeps), apparently disappearing from the quadrats and not reappearing following heavy rainfall. Irruptive species, which were granivorous, nectarivorous or insectivorous, included species first recorded after heavy rainfall. Some species often considered to be nomadic, such as White-fronted (Phylidonyris albifrons) and Pied (Certhionyx variegatus) Honeyeaters, appeared to be both sedentary—resident and ir...

Breeding habitat of the Cook’s Petrel (Pterodroma cookii) on Little Barrier Island (Hauturu): implications for the conservation of a New Zealand endemic

Abstract: Cook’s Petrel (Pterodroma cookii), a trans-equatorial migrant endemic to the New Zealand archipelago, is today endangered and restricted to island habitats at the northern and southern extents of its former range. To improve the limited knowledge of the breeding habitat of this species, we combined an island-wide survey, the mapping capabilities of geographic information systems, and logistic and autologistic analyses to examine burrow distribution and habitat use of the world’s largest population of Cook’s Petrel, on Little Barrier Island (Hauturu). Our results show that, on this island, Cook’s Petrel breeds predominantly above 300 m above sea level, on steeper slopes, closer to ridge tops, and in unmodified forest habitats with low and open canopies and greater numbers of large stems compared to the available terrain and habitat. Within these habitats above 300 m, densities of burrows are 0.04 burrows m–2. Through comparisons with habitat data from two low-altitude colonies, we conclude that the current distribution of this population is a result of habitat selection and historical human-mediated impacts. We suggest that mature forest habitats, close proximity to ridge tops, and steep slopes are key habitat requirements for this species. A large amount of suitable habitat is available for Cook’s Petrel on Little Barrier Island and the recent removal of introduced predators is expected to result in an expansion of this population. The results of the current study provide useful information to aid in the restoration of former colony sites on other islands and the New Zealand mainland.

Differences in breeding success between African Penguins (Spheniscus demersus) that were and were not oiled in the MV Treasure oil-spill in 2000

Abstract: About 19 000 African Penguins (Spheniscus demersus) were oiled when the bulk ore carrier MV Treasure sank off the west coast of South Africa in June 2000. Of these, more than 17 000 Penguins were cleaned, rehabilitated and released back to the wild. The breeding success of these birds was compared with unoiled birds and birds oiled during other oil-spills, by measuring fecundity, hatching success and fledging success from 2001 to 2005 on Robben Island. Fledging success averaged 61% in birds that were not oiled in the Treasure spill and 43% in birds oiled during the Treasure event, with a large proportion of the reduction attributable to higher mortality of older chicks. Factors that may have contributed to differential fledging success include long mean intervals between capture and cleaning (22 days) and between capture and release (48 days) for birds oiled in the Treasure spill. One implication of these results is, if a similar large spill should occur in the future, every effort should be made to treat the oiled birds as quickly as possible to reduce the risk of their suffering a similar reduction in breeding productivity. Further, the other interventions, such as relocation of unoiled birds and captive-rearing of orphaned chicks may need to receive higher priority than hitherto.

Temporal variation in food resources determines onset of breeding in an Australian mistletoe specialist

Abstract: Temporal variation in the onset of breeding has been described for various species in a range of systems. Many of these studies have found a relationship between the timing of breeding and resource levels leading to a matching of life-history stages to resource abundance. However, most of this work has been conducted in northern hemisphere temperate zones – highly regular systems where temperature and other climatic factors have a predictable influence over food abundance. We present data gathered over two years on the timing of breeding in a nomadic mistletoe specialist, the Painted Honeyeater (Grantiella picta), relative to temporal variation in the abundance of its main food resource, fruit of the Grey Mistletoe (Amyema quandang), in an Australian semi-arid environment. Arrival and departure of the breeding population occurred either side of peak mistletoe fruiting in both years. Clutches were initiated on average on Day 66 of the breeding season (assigned as 1 October for both years) in 2004 (5 December) and Day 49 (18 November) during 2005, i.e. 17 days earlier in 2005. Abundance of mistletoe fruit peaked in January in both years but increased significantly earlier in 2005. Abundance of fruit was almost identical at the mean clutch initiation dates in both years, reaching comparable levels 19 days earlier in 2005. The timing of life-history stages followed the progression of fruiting phenology and was closely matched to resource levels despite marked differences in the temporal availability of fruit between years. Painted Honeyeaters appear similar to northern hemisphere passerines that use photoperiod to time their overall breeding season and then incorporate information from the local environment to fine-tune initiation of breeding. By cuing directly on the food resource, Painted Honeyeaters may avoid temporal mismatching in this highly unpredictable environment.

Trends in numbers of Cape Cormorants (Phalacrocorax capensis) over a 50-year period, 1956–57 to 2006–07

Abstract: The population trend of Cape Cormorants (Phalacrocorax capensis), a species endemic to southern Africa and that feeds mainly on shoaling pelagic fish, is described for a 50-year period, from 1956–57 to 2006–07. The main breeding localities for the species are grouped in three regions in the Benguela upwelling ecosystem: guano platforms off central Namibia, islands off southern Namibia and islands off South Africa’s Western Cape Province. From 1956–57 to 1978–79, the numbers breeding off Namibia increased, as a result of increased availability of breeding space and adequate supplies of food. In the same period, numbers remained stable in the Western Cape. Numbers decreased off southern Namibia in the early 1980s and off central Namibia in the early 1990s, when environmental perturbations reduced the availability of food. Numbers decreased in the Western Cape in the early 1990s, following periods of scarcity of anchovy (Engraulis encrasicolus), an important prey item, and an outbreak of avian cholera caused by the bacterium Pasteurella multocida. They remained low as cholera outbreaks continued and some pelagic fish were displaced to the east beyond the foraging range of breeding Cormorants. The overall population of Cape Cormorants was of the order of 100 000 pairs in 1956–57, increased to ~250 000 pairs in the 1970s, but reverted to ~100 000 pairs in 2005–06.

The gradual loss and episodic creation of Palm Cockatoo (Probosciger aterrimus) nest-trees in a fire- and cyclone-prone habitat

Abstract: We present information regarding the rate of loss of nest-hollows over a long period in the tropics, and a dramatic episode of nest-hollow creation following two tropical cyclones. We followed the fate of 61 Palm Cockatoo (Probosciger aterrimus) nest-trees over a period of 6 years (1999 to 2005). On average, 48 trees were monitored each year. During this time 16 (26.2%) were rendered unusable for Palm Cockatoos; their final cause of loss was fire (n = 10; 62.5%), wind (n = 4; 25%), and intense decay where the tree was left standing but unusable (n = 2; 12.5%). On average, 5.2% of nest-trees were lost each year. Dead trees were more likely to be destroyed than living trees. Individual Palm Cockatoos build nests in multiple hollows, a subset of which are used for actual breeding whereas the rest are used for display purposes only (inactive nest-trees). Inactive nest-trees were also more likely to be destroyed than active trees, suggesting Palm Cockatoos actually breed in nest-trees that are more durable. We revisited our study area in July 2006, following two severe tropical cyclones. Most of the known nest-trees that we visited after the cyclones were still standing. The first cyclone created ~0.02 new nesting opportunities per hectare, whereas the second created 0.19. The differences between the two cyclones can be explained by their different paths and different radii of destructive winds in relation to our study area. While the loss of nest-trees owing to fire is significant, and should be monitored given that they are a limiting resource (Murphy et al. 2003), our results suggest that fire management should focus more on maintaining adequate recruitment of large trees, which could be affected by excessively frequent burning.

Migration ecology and morphometrics of two Bar-tailed Godwit populations in Australia

Abstract: Bar-tailed Godwits (Limosa lapponica) are long-distance migratory shorebirds. About a third of the global population migrate to Australia during the non-breeding season where they occur mainly in the north-west and east. Using measurements of bill, wing, tarsus and total-head (head and bill), we show that birds from the two main Australian non-breeding regions belong to separate populations. Individuals in north-western Australia are subspecies L. l. menzbieri, which breeds in north-eastern Russia, whereas those in south-eastern Australia are subspecies L. l. baueri, which breeds in northern and western Alaska. Resightings and recoveries of marked birds showed that there is little exchange between the two populations on the non-breeding grounds. They also take different routes during northward migration: L. l. menzbieri was more frequent on staging areas in the western Yellow Sea and largely absent from Japan, whereas L. l. baueri was more numerous in the eastern Yellow Sea and was often recorded in Japan. L. l. baueri left on northward migration 1–2 weeks earlier than L. l. menzbieri and gained more body mass before departure, presumably in preparation for a longer migratory leg. Our data suggest that on northward migration, L. l. menzbieri and L. l. baueri make direct flights of 5400–6200 km and 8200–8500 km, respectively, to reach staging areas in East Asia. The route of Limosa l. menzbieri on its southern passage is similar to that of northward migration, with stop-overs in East Asia. Limosa l. baueri, however, make an ~10 400-km non-stop flight across the Pacific Ocean from Alaska to eastern Australia, one of the longest non-stop migratory flights known amongst birds.

Differential migration of shorebirds in the East Asian—Australasian Flyway

Abstract: Differential migration involving intraspecific segregation of ages or sexes on the non-breeding grounds is common among migratory birds. Most of the existing data have, however, been collected in Europe and the Americas and very little is known about such migration patterns in the East Asian–Australasian Flyway, which links eastern Siberia with Australia and New Zealand. Spatial segregation of males and females during migration and at non-breeding grounds has clear implications for conservation management, as the loss of habitat predominantly used by members of one sex will disproportionately reduce effective population size. Here, I review the published data on differential migration in shorebirds in the East Asian–Australasian Flyway and discuss these data in the context of alternative hypotheses for differential migration and their relevance to existing conservation programs.

Home-range of the Powerful Owl (Ninox strenua) in dry sclerophyll forest

Abstract: Since European settlement of Australia, the dry open forests and woodlands of central Victoria have been extensively cleared and most large trees harvested, resulting in a decline of arboreal mammal populations The Powerful Owl, which was formerly reliant on these prey species, still persists in the region but at very low densities and uncertain viability Previous research has shown that Powerful Owls select home-ranges with more large trees and hollows than the forest at large, but the amount of such habitat that is required remained undefined Four adult Powerful Owls (two males and two females) from four pairs occupying geographically separate territories in box-ironbark forest were radio-tracked over 1–6 months Home-range size was much greater than previously assumed for this species (minimum convex polygon of 4774, 2896, 1770 and 1382 ha) Range-length was 57–89 km, and on average 5–12% of each home-range was used during a single night Core foraging areas comprised many, typically small, patches scattered across the entire home-range Selection of roosting sites was flexible and did not constrain spatial use of home-range, with 96% of roosts in very small to medium-sized trees, which are widely distributed The finding of unexpectedly large foraging ranges suggests that enhancement of habitat quality and mammalian prey abundance in currently occupied home-ranges is the foremost goal for forest managers if a viable population is to be sustained

Microclimate of nesting burrows of the Rainbow Bee-eater

Abstract: Burrow-nesting affords protection from predators and climatic extremes, but potentially can pose physiological ‘problems’ for developing birds and attendant adults. Microclimate parameters of burrows of breeding Rainbow Bee-eaters (Merops ornatus) were measured to assess whether they presented such difficulties for young and adults. Estimated mean volume of the brood-chamber was ~4.5 L. Relative humidity was typically 100% in the brood-chamber and chamber air temperature was constant, averaging 4–6°C above ambient levels. The temperature regime of the burrow probably resulted in low thermoregulatory costs for attendant adults and endothermic nestlings. The chamber oxygen (O2) fraction (mean 19.35%) was always lower than ambient values, but mostly not sufficiently low to be problematic for the growing young. Mean pre-internal pipping absolute oxygen consumption rate of embryos (62.9 ± 13.8 mL O2 day–1) did not appear to be strongly influenced by either the protracted incubation period or the reduced O2 partial pressure of the chamber atmosphere. Mean eggshell water-vapour conductance (8.95 mg day–1 kPa–1) was tuned to egg mass rather than egg mass/incubation period. However, eggs still lost ~15% of their mass during incubation because the influence of the small water-vapour pressure difference across the shell (2.91 kPa) and the protraction of the incubation period apparently counteracted each other.

A wild goose chase - temporal and spatial variation in the distribution of the Magpie Goose (Anseranas semipalmata) in Australia

Abstract: At the time of European settlement in Australia in 1788, Magpie Geese (Anseranas semipalmata) were abundant, as they remain today, across northern Australia but were also common on swamps and on coastal and inland river floodplains in south-eastern Australia. However, by the early 1900s Magpie Geese had suffered a serious contraction of range from the south-east. In this study, we review all available records of the Magpie Goose and compile a list of processes potentially causing their decline. Historical changes in distribution are then compared with time frames of threatening processes to identify processes most likely to have driven the observed changes. The results suggest that the decline was primarily from loss of wetland habitat and hunting, although lesser threats such as poisoning, predation by Red Foxes (Vulpes vulpes) and severe drought may have increased the rate of decline. Since protection of the species from hunting in the 1930s in eastern and southern states and successful reintroductions in Victoria, New South Wales and South Australia, the species has returned to parts of its former range. However, populations are unlikely to return to their former numbers in the south-east as management of water resources has greatly reduced areas of breeding habitat and drought refuges. We suggest a program of management for southern populations of the Magpie Goose that includes long-term monitoring, engagement of landholders, identification and protection of existing wetlands, creation of new habitat, and reduction of disturbance from humans, introduced pests and livestock.

Breeding biology of the Flesh-footed Shearwater (Puffinus carneipes) on Woody Island, Western Australia

Abstract: The Flesh-footed Shearwater (Puffinus carneipes) is a pelagic seabird that breeds predominantly around southern Australia and New Zealand. Its breeding biology is poorly known, particularly in Western Australia where the species is known to have suffered mortality during long-line fishing operations. We studied the breeding biology of the Flesh-footed Shearwater on Woody Island, off the southern coast of Western Australia, between 2000 and 2003, from the post-migratory return of adults to the colony until the departure of the last fledglings 7 months later. Shearwaters dug single-tunnelled burrows slightly over 1 m long (1050 ± 16 mm (s.e.)) in soil >350 mm deep, during October, before embarking on an unsynchronised pre-laying exodus through November. Eggs were laid in the last week of November, and incubated over 54 ± 7 days during December and January, before hatching in mid- to late January. The fledglings left in late April–early May after spending an average 101 ± 0.9 days in the burrow. A logistic growth model, fitted to weekly measurements of skeletal body components, determined that the head, bill and tarsus grew rapidly during early burrow life, while growth of the wing was slow initially and remained incomplete at fledging. Breeding success was measured as 40% and 53% for two successive seasons, and was greater from burrows on a medium gradient than those on slighter gradients in both seasons. Although baseline data are provided here, longer term studies addressing specific demographic parameters, such as adult survival, juvenile recruitment and fecundity, are needed to assess the population status and guide management actions.

Does the integrity or structure of mallee habitat influence the degree of Fox predation on Malleefowl (Leipoa ocellata)

Abstract: Malleefowl (Leipoa ocellata) are in decline across their range. Previous studies have found that the survival rate of young Malleefowl is low, the single greatest cause of mortality being predation by the introduced Red Fox (Vulpes vulpes). Many of these studies, particularly those in New South Wales (NSW), were conducted in habitats that were heavily modified by fire, exotic herbivores or plant harvesting. In this paper, we examine the survival of Malleefowl in relatively undisturbed mallee habitats within two conservation reserves in South Australia (SA). Both reserves were long unburnt and free of large exotic herbivores, but differed greatly in understorey structure. Fifteen young captive-reared Malleefowl were released into each reserve. In all, 70% of these individuals were dead within 40 days. Fox predation was the prime cause of mortality, accounting for at least 30%, and perhaps as much as 96%, of all deaths. The extent and causes of mor- tality were similar in the two reserves. The overall level of Malleefowl survival was (1) better than that recorded in more disturbed habitat in NSW in the absence of any Fox control, but (2) substantially less than that in NSW after widespread Fox control was implemented. This study indicates that Malleefowl in SA are subject to significant levels of Fox predation, even in relatively undisturbed habitats. Also, for the two mallee habitats examined, evidence suggests that understorey structure had no influence on the degree of predation. Available data indicate that during the past two decades Malleefowl populations in SA have declined at about the same rate as those in NSW. Current densities in SA are typically about one- quarter of what they were 15 years ago. We conclude that habitat integrity and structure have little effect on the interaction between Foxes and Malleefowl, and suggest that Malleefowl populations across Australia are threatened by Foxes, placing the species at substantial risk of extinction.

Predicting spatio-temporal distribution for eastern Australian birds using Birds Australia's Atlas data: survey method, habitat and seasonal effects

Abstract: Faunal atlases are landscape-level survey collections that can be used for describing spatial and temporal patterns of distribution and densities. They can also serve as a basis for quantitative analysis of factors that may influence the distributions of species. We used a subset of Birds Australia’s Atlas of Australian Birds data (January 1998 to December 2002) to examine the spatio-temporal distribution patterns of 280 selected species in eastern Australia (17–37°S and 136–152°E). Using geographical information systems, this dataset was converted into point coverage and overlaid with a vegetation polygon layer and a half-degree grid. The exploratory data analysis involved calculating species-specific reporting rates spatially, per grid and per vegetation unit, and also temporally, by month and year. We found high spatio-temporal variability in the sampling effort. Using generalised linear models on unaggregated point data, the influences of four factors – survey method and month, geographical location and habitat type – were analysed for each species. When counts of point data were attributed to grid-cells, the total number of species correlated with the total number of surveys, while the number of records per species was highly variable. Surveys had high interannual location fidelity. The predictive values of each of the four factors were species-dependent. Location and habitat were correlated and highly predictive for species with restricted distribution and strong habitat preference. Month was only of importance for migratory species. The proportion of incidental sightings was important for extremely common or extremely rare species. In conclusion, behaviour of species differed sufficiently to require building a customized model for each species to predict distribution. Simple models were effective for habitat specialists with restricted ranges, but for generalists with wide distributions even complex models gave poor predictions.

An estimate of the population sizes of Black-browed (Thalassarche melanophrys) and Grey-headed (T. chrysostoma) Albatrosses breeding in the Diego Ramírez Archipelago, Chile

Abstract: The Diego Ramirez Archipelago, Chile, is the southernmost albatross breeding ground in the world and holds globally important numbers of Black-browed (Thalassarche melanophrys) and Grey-headed (T. chrysostoma) Albatrosses. A census in the Diego Ramirez Archipelago has been attempted only once, in 1980–81, with methods that were unlikely to determine population sizes accurately. The number of breeding pairs of both species was estimated in the incubation period of 2002 using a combination of aerial photography, ground-based photography, yacht-based photography and ground counts. All islands in the archipelago were surveyed. There were an estimated 55 000 pairs of Black-browed and 17 000 pairs of Grey-headed Albatrosses breeding at the archipelago. Based on the results of this census, and those for the other four known breeding locations, the populations of both species of albatrosses in Chile are considerably larger than previously reported, comprising ~20% of the Black-browed Albatrosses and 23% of Grey-headed Albatrosses in the world, with the largest populations of both species occurring in the Diego Ramirez Archipelago.

The effect of bill structure on seed selection and handling ability of five species of granivorous birds

Abstract: The relationships between bill morphology and seed characteristics (size and nutrients) with regard to feeding were investigated in five species of bird belonging to three families of granivorous p...

Climatic variation and breeding in the Australian Magpie (Gymnorhina tibicen): a case study using existing data

Abstract: To anticipate the effects of climate change on Australia’s avifauna, it is first necessary to understand the current effects of climate (including climate variability) on life histories, and to examine the scope and nature of existing data that may provide the necessary historical context to anticipate the effects of climate change. This study examines naturally occurring geographical gradients (altitude, latitude) and the Southern Oscillation Index (SOI) as integrated measures of climate. These are then compared with the timing and ‘amount’ of breeding recorded for the Australian Magpie (Gymnorhina tibicen) using data from Birds Australia’s Nest Record Scheme and Atlas of Australian Birds, the NSW Bird Atlassers Inc.’s NSW Bird Atlas, and the Canberra Ornitholgists Group’s Garden Bird Survey. For this common, easily identified species, these data suggest links between Australian Magpie breeding and all three environmental variables. Breeding became later as altitude increased, the proportion of breeding records increased from north to south, and years of high SOI corresponded to more (and earlier) breeding in this species. That annual climatic fluctuations have a direct, immediate and substantial effect on breeding in the Australian Magpie, particularly on the amount of breeding that occurs, implies that longer term changes in climate will have substantial impacts on populations. Results were not solely temperature-driven, which makes predicting climate change impacts difficult. For rainfall, predictions are far less precise and regional variation is higher. The results also highlight the potential and limitations of current survey techniques for documenting the impacts of climate change on birds; in particular, the Nest Record Scheme does not measure the amount of breeding that occurs, but a useful index of this can be derived from bird atlassing data.

Diet of the Lesser Rhea (Pterocnemia pennata) and availability of food in the Andean Precordillera (Mendoza, Argentina)

Abstract: The food and foraging strategies of the Lesser Rhea (Pterocnemia pennata) were studied in the high arid pampas of the Andean Precordillera in Mendoza, Argentina. The Lesser Rhea is primarily herbivorous and the composition of, and seasonal changes in, the diet were analysed in relation to the availability of vegetation. The analysis of vegetation and sampling of faeces were carried out in spring, summer and autumn 2002–03. Grasses and shrubs dominated the vegetation of the study area, while forbs and cactus (Cactaceae) were present only in low proportions. The main dietary component was leaf matter (94.30%), with the rest seeds (5.66%) and a small proportion of insects (0.03%). Stones constituted 2.24% of the dry weight of faeces. The diet included 70% of the available plant species in the area. Rheas showed a preference for forbs and shrubs in relation to the availability of these plant-types and, while grasses were the dominant plant-type in the environment, they were not selected in relation to their availability; Rheas showed no preference for cactuses. Dietary diversity (Shannon–Wiener index of diversity of plant species in the diet = 0.77) exceeded environmental diversity (Shannon-Wiener index = 0.29). The diet of the Lesser Rhea in the Andean Precordillera of Mendoza was almost completely herbivorous and generalist, although selective for some plant species, features that would constitute an adaptation to survive in this clearly arid environment.

Monitoring population change in the cryptic and threatened Western Ground Parrot in relation to fire

Abstract: Measures of abundance and population trends are necessary for informed management of rare species, but obtaining reliable estimates of sparsely occurring species is an ongoing challenge in conservation biology It is even more difficult when the species of interest is also cryptic We censused a population of one such species, the Western Ground Parrot (Pezoporus wallicus flaviventris), over several years to develop a monitoring protocol to assist in future management, extend understanding of its response to fire, and provide a model that could be used with other cryptic bird species Abundance of Western Ground Parrots, monitored by means of calling frequencies, varied from year to year at a study site in Fitzgerald River National Park, south-western Australia Frequency of calling increased significantly from 1996 to 2000 During this time, frequency of calling peaked in 1998 in part of the study site that had been unburnt for more than 40 years, and remained high in 2000 Frequency of calling was similar in a more recently burnt part of the study area except in May 1998, when frequency was lower following a fire that burnt part of this area five months previously Frequency of calling dropped significantly in both the long unburnt and recently burnt areas between 2000 and 2004; exact reasons for this are unknown Western Ground Parrots can use recently burnt vegetation where it is immediately adjacent to an established population, but do not need fire to create habitat, at least in the timescale of 40 years The current monitoring protocol, where eight listening posts are counted approximately three times each, is capable of detecting an annual change in frequency of calling of ~13% The number of listening posts would need to be increased to 14 in order to detect an annual change of 10%, and would need to be increased to 40 in order to detect an annual change of 5%

Using biometric measurements to determine gender of Flesh-footed Shearwaters, and their application as a tool in long-line by-catch management and ecological field studies

Abstract: We examined sexual dimorphism in 11 morphological characters of the Flesh-footed Shearwater (Puffinus carneipes) and used these characters in a discriminant function analysis (DFA) to enable sexual classification in the field. We also used molecular techniques to determine gender in live birds. Sexual dimorphism was present in all characters tested, with males (n = 50) significantly larger than females (n = 52) in all cases. A stepwise DFA of the 11 morphological characters resulted in gender being correctly assigned in 91% of birds using head–bill length (HBL), minimum bill-depth (MBD), and superior unguicorn-width (SUW), using the generalised function –48.360 + (0.661 × SUW) + (0.931 × MBD) + (0.334 × HBL). Of the nine misclassifications, seven were a result of females being incorrectly assigned as males, indicating an overlap between the upper cut off value for females with the lower threshold value for males. We applied the DFA to an existing morphometric dataset (n = 219) of Flesh-footed Shearwaters caught as incidental by-catch from long-line fishing in the Eastern Tuna and Billfish Fishery. The generalised discriminant function derived from live birds performed poorly when applied to the by-catch sample (only 68.5% correctly sexed), and the issues of data consistency and the application of discriminant functions between populations are discussed. A two-character DFA constructed from the by-catch dataset (–30.128 + 0.206 × HBL + 0.848 × MBD) resulted in 86% of by-catch birds being correctly sexed. The findings suggest that a combination of the morphological traits HBL, MBD and SUW are sufficiently robust to use in the field to determine the gender of live birds. The merits and application of this technique are discussed in relation to seabird conservation and management.

Nesting success and apparent nest adornment in Diamond Firetails (Stagonopleura guttata)

Abstract: The nesting biology of Australia’s endemic Diamond Firetail (Stagonopleura guttata) is poorly known. However, Diamond Firetails are known to weave flowers into the entrance of their nests sometimes, although the function of this behaviour is not known. This study used field and aviary data to address the following questions: (1) What proportion of nests in the wild have flowers woven into the nest-entrance? (2) Are nests with flowers more successful than nests without flowers? (3) Does the vegetation of the nest-site predict nesting outcome? (4) How often do wild birds reuse nests across years for breeding? (5) Do birds have a preference for stem-length or presence of flowers when selecting nesting material in aviaries? The field data showed that 70% of nests had flowers woven into the entrances, but with significant annual variation in the number of flowers at nest-entrances, with > 30 flowers per nest in 2004 and < 10 flowers per nest in 2005. Most (96%) natural nests were depredated (100% in 2004, and 91% in 2005), and we could not examine the role of vegetation of the nest-site in determining predation outcome. Using artificial nests with and without flowers we found no effect of the presence or absence of flowers on predation outcome, which suggests that flowers do not increase the conspicuousness of the nest for predators. However, there was an effect of nest concealment. Nests more exposed on the sides and below were depredated more than nests with greater concealment. Aviary data showed Diamond Firetails had a clear preference for longer stems over shorter stems for nest-building, irrespective of the presence of flowers. We conclude that the flowers observed at nests were a by-product of the preference for stem-length for nest-building. This finding helps to explain the inconsistency among anecdotal studies reporting the presence of flowers at nests of Diamond Firetails across Australia.

The digital tendon locking mechanism of owls: variation in the structure and arrangement of the mechanism and functional implications

Abstract: This study provides evidence of morphological differences in support of the current phylogenetic division of the owls into two familes (Strigidae, Tytonidae), with respect to the digital tendon locking mechanism (TLM). This mechanism consists of modified surfaces on the flexor tendons in the digits, which, when engaged form a lock that holds the digits in a flexed position. Although species-specific differences in TLM structure were apparent, consistent inter-family differences occurred in the degree of expression of the TLM, its location within the digit, and in the structure and arrangement of the locking elements. Phylogenetic differences also occurred in the location of the associated digital ligaments. The TLM of the Strigidae was found to resemble that of the Falconiformes (Falconidae and Accipitridae). However, the Tytonidae possess a more distinctive pattern, characterised by a digit 1 TLM located at the opposite end of the digit and bearing reversed plicae. The biomechanics of the mechanism are considered, along with the functional implications of the varying structures in an attempt to understand the adaptiveness, or otherwise, of this-little known structure within an avian order.

Patterns of supra-canopy flight by pigeons and parrots at a hill-forest site in Papua New Guinea

Abstract: It is important that conservation strategies consider the needs of taxa that range over large areas or make significant daily or seasonal movements across areas or habitats, but data on movements in most tropical animal species is lacking. We examined frequency, direction, and temporal variation in supra-canopy flight activity (number of individuals recorded per hour of recording) of eight species of parrot and seven species of pigeon over 5 months in a New Guinean hill-forest. Papuan Mountain Pigeon (Gymnophaps albertisii) contributed 44% of all flights and Sulphur-crested Cockatoo (Cacatua galerita) 17%; while 95% of 1800 flights were made by seven species. Directions of flights were non-random in nearly all species. There was a significant movement of Papuan Mountain Pigeon, and smaller movements of Dusky Lory (Pseudeos fuscata), Rainbow Lorikeet (Trichoglossus haematodus) and Eclectus Parrot (Eclectus roratus), towards lower altitudes in the mornings and a varying return to higher altitudes in the afternoons. Most species made more supra-canopy flights in the mornings than the afternoons but the exact patterns of flight differed between species. Flight activity varied significantly between months in several species, and flight activity tended to be highest during periods of breeding in most frugivorous birds. Large-bodied species made more supra-canopy flights than did smaller species, but there was no relationship across species between ‘on-the-ground’ bird densities and flight-frequency. Breadth of frugivorous diet (determined by review of the literature) did not influence flight-frequency. The factors that underpin the highly variable patterns of movement were identified. How these patterns might be affected by changes in land-use is important for landscape-level conservation, especially for those species that make systematic long-distance movements.

Feeding ecology of the White-tailed Hawk (Buteo albicaudatus) in south-eastern Brazil

Abstract: The feeding ecology of the White-tailed Hawk (Buteo albicaudatus albicaudatus) was studied in south-eastern Brazil. The aims of this study were to: (1) quantify the diet of the White-tailed Hawk, including the number of prey species eaten and their biomass; (2) investigate the influence of season on diet; and (3) describe the breadth of the diet. Pellets found beneath seven White-tailed Hawk nests and several roosting sites around the nesting sites were collected from September 2000 to September 2001. The analysis of 259 pellets revealed 31 prey species or morphospecies, 3296 individuals and 7.2 kg of estimated consumed biomass. Five insect orders (Hymenoptera, Heteroptera, Odonata, Isoptera and Lepidoptera) and one vertebrate order (Chiroptera) were reported as prey for the first time for this species. By number, invertebrates made up 88% of all prey items, 63% of which belonged to a single orthopteran family (Acrididae). Among vertebrates, rodents were the group most consumed by number and represented 73% of all vertebrate prey items. However, in terms of estimated biomass consumed, the most represented groups were rodents (50%), orthopterans (21%), birds (11%) and lizards (7%). Vertebrates alone yielded 77% of the total biomass consumed. Whereas the White-tailed Hawk may be classified as insectivorous by number of prey, it is carnivorous with respect to biomass ingestion. According to the Levin’s diet-breadth index, this raptor could be considered to be a specialist predator of grasshoppers (Acrididae) by prey number and of rodents by prey biomass. Food eaten was dependent on season, with more mammals taken during the dry (breeding) season and a broader range of prey during the wet season.

Seasonal and habitat-related changes in population density of North Island Saddlebacks (Philesturnus rufusater) on a small island: using distance sampling to determine variation

Abstract: We applied line-transect distance sampling to look at small-scale seasonal and habitat-related changes in abundance of North Island Saddlebacks (Philesturnus rufusater) on a small protected offshore island. We also assessed the recovery of Saddleback density in a mature forest patch on the island after removal of a small number of Saddlebacks for translocation (harvesting). From June 2003 to June 2004, we conducted 34 km of line-transect surveys on 15 transects in five forest patches (two mature forest patches, two replanted forest patches and the harvested mature forest patch). Different seasonal trends were identified for the two habitat types. Densities varied in replanted forest from a low of 3.18 ± 2.9 ha–1 (95% confidence intervals (CI)) in December–January (austral summer) to a high of 18.9 ± 2.5 ha–1 (95% CI) in April–May (austral autumn). In remnant mature forests, density varied less and ranged from a low of 5.23 ± 3.74 ha–1 (95% CI) in June–July (austral winter) to a peak of 14.2 ± 2.55 ha–1 (95% CI) in April–May. Differences in the densities of Saddlebacks in harvested and mature forest patches did not vary significantly. Juvenile density was higher than adult density in replanted patches, and we suggest that the decline in density in spring was caused by juvenile mortality. Although obtaining such detailed density estimates required considerable effort (34 km), this study has provided a current estimate of North Island Saddleback numbers on Tiritiri Matangi Island and has monitored a translocation source population. Finally, this analysis has highlighted testable hypotheses regarding juvenile dispersal and mortality, and seasonal use of different habitat types.

Estimating and reducing the amount of Plains-wanderer (Pedionomus torquatus Gould) habitat sprayed with pesticides for locust control in the New South Wales Riverina

Abstract: The potential effects of pesticides used to control locusts in the New South Wales Riverina on the endangered Plains-wanderer (Pedionomus torquatus) have been of concern since the early 1980s. We used geographical information systems (GIS) to determine the intersection of primary and secondary Plains-wanderer habitat areas with historical locust-control data and provide estimates of the area of Plains-wanderer habitat sprayed by the Australian Plague Locust Commission for control of locusts between 1977 and 2005. Peaks among these estimates, expressed as a percentage of the identified habitat occurring on nine 1 : 100 000 map sheets within the New South Wales Riverina study area, corresponded with years of peak locust control activity, although the proportion of habitat affected was less than expected. The maximum amount of habitat exposed to pesticides occurred in 1993–94, when ~16% of primary and 12% of secondary Plains-wanderer habitat was sprayed. Locust-control protocols during 2004–05 were altered to reduce the amount of Plains-wanderer habitat sprayed with fenitrothion from 16% to 1.5%, and to increase the use of the biological control agent, Metarhizium anisopliae var. acridum (Green Guard®), over plains-wanderer habitat from 0% to 3.6%. The use of Green Guard® during future locust control within Plains-wanderer habitat in the Riverina has been recommended in the draft NSW Plains-wanderer recovery plan (New South Wales National Parks and Wildlife Service 2002).

Breeding patterns of King Penguins on the Falkland Islands

Abstract: The breeding biology of the King Penguin (Aptenodytes patagonicus) has been investigated in detail at sites across its circum-subantarctic range, except at its most temperate location, the Falkland Islands. Aspects of the breeding biology of King Penguins, including timing of laying, brooding and fledging and the length of shifts during incubation and brooding, were studied in the Falkland Islands during the 2001–02 breeding season. The first peak in numbers of pre-nuptial moulting individuals occurred during October and eggs were laid from early November to mid-March. Incubation shifts lasted 10–18 days, and shifts undertaken during the 34-day brooding period were 4–9 days in duration. Foraging trips during the early creching period were 4–16 days in duration. Chicks that hatched before 22 January reached a mean asymptotic body mass of 8.8 kg in April, while later-hatched chicks increased in mass until July but reached a significantly lower body mass of 7.7 kg. Survival of chicks over winter was high (89%), which may be associated with lower rates of avian predation and less severe weather conditions in the Falkland Islands compared with other breeding sites. Chicks began fledging in mid-November. Late breeders who laid in January and February had a high rate of breeding success. Further research is required at this most temperate colony to confirm the early timing of breeding and the high success rates of early and late breeding attempts.

Changes in the spatial distribution of migratory shorebirds along the Shanghai shoreline, China, between 1984 and 2004

Abstract: Migratory shorebirds in the East Asian–Australasian Flyway use the Shanghai shoreline as an important stopover site. Until recently, little was known about the influence of intensive reclamation on the shorebirds using this shoreline. We investigated the distribution of shorebirds in 10 fixed-sample sites in 2004–05 and compared the results with those of surveys at the same sites in 1984–85; we also examined physical changes in intertidal wetlands and coastal land-use at these sites. In 2004–05, 25 shorebird species were recorded, and the seasonal abundance of shorebirds in 2004–05 was similar to that recorded in the 1980s, but the number of species observed in both northern and southern migration periods declined between 1984–85 and 2004–05 even though the overall numbers of birds had not. Since the 1980s, over 500 km2 of intertidal mudflats along the Shanghai shoreline have been reclaimed, though ~190 km2 of these mudflats have been reclaimed but not yet developed and could be considered fairly high-value habitat for shorebirds. Most of the shorebirds that were observed were on these reclaimed but undeveloped mudflats. The physical characteristics of the mudflats had been transformed over the preceding two decades through reclamation, siltation, erosion and, at some sites, artificial vegetation planting, and two habitat variables – the width of mudflats and the width of the upper intertidal zone – significantly affect the abundance and distribution of shorebirds. We discuss some implications for conservation related to rules and guidelines for reclamation of wetlands, and make recommendations on land-use procedures for artificial wetlands.

Foraging behaviour of the Common Myna (Acridotheres tristis) in relation to vigilance and group size.

Abstract: Foraging individuals allocate time to foraging behaviour or anti-predator vigilance, but rarely both at the same time. If we assume that foraging rate (that is, the number of foraging attempts per minute) decreases as a function of time spent vigilant, an individual can directly increase food intake by reducing time spent vigilant. Alternatively, it may increase food intake by increasing foraging effort, that is, making more foraging attempts in the time remaining after time devoted to anti-predator vigilance is excluded. I studied the foraging behaviour of the Common Myna (Acridotheres tristis) to determine foraging behaviour under different conditions of human disturbance (indirect predation risk), time of day and group size. The results showed that Mynas generally increased their food intake by increasing foraging effort, rather than decreasing vigilance behaviour. Although joining a group resulted in significantly lower levels of vigilance behaviour, it did not increase foraging rate or food intake. Despite being well adapted to the human environment, and having few natural predators, Mynas showed high levels of anti-predator vigilance, at least within the resource rich urban environment. These results are discussed in the light of possible management options to control this highly invasive bird.

The five-year change process at a secondary school: A case study

Abstract: The Five-Year Change Process at a Secondary School: A Case Study by LuAnne Marie Forrest Dr. Patti Chance, Committee Chair Associate Professor of Education University of Nevada, Las Vegas This study explored the five-year change process as experienced by members of a secondary school community who intentionally sought out and pursued school improvement through the establishment of a continuous improvement process with the goal of increased student achievement. Three questions guided this exploration: (a) What contextual factors contributed to the change process at a secondary school pursuing continuous improvement processes; (b) How did these contextual factors interact and inter-relate to contribute to the implementation and sustainability of the eontinuous improvement process; and (c) How did these contextual factors interact and inter-relate to contribute to the change process itself. As such, this study involved a close examination of the phenomenon of change as it existed within the complex situational and contextual conditions of the school organization. This was a longitudinal, exploratory single-case study with an historical analysis. Qualitative tools used to conduct this exploration included an extensive document review, an open-ended observation and twenty semi-structured interviews of teachers, teacher-leaders, administrators, parents and district leaders. Data were analyzed on three levels: chronologically, categorically and from the perspectives of multiple stakeholder groups. Within categories, data were analyzed for patterns and relationships using content and constant comparative analyses.