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Emu - Austral Ornithology
Volume 115, Issue 1, 2015 Summaries
Editorial: A quantum leap in avian biology
Leo Joseph and Katherine L. Buchanan
Emu – Austral Ornithology 115(1), 1–5
http://www.publish.csiro.au/paper/MUv115n1_ED.htm
The frequency of ingested plastic debris and its effects on body condition of Short-tailed
Shearwater (Puffinus tenuirostris) pre-fledging chicks in Tasmania, Australia
Hannah R. Cousin , Heidi J. Auman , Rachael Alderman and Patti Virtue
Emu – Austral Ornithology 115(1), 6–11
http://www.publish.csiro.au/paper/MU13086.htm
Observations of wildlife deaths and injuries from entanglement in or ingestion of plastic debris are
increasing around the world. Seabirds in particular are facing greater exposure to this threat as levels
of marine plastic pollution increases. Short-tailed Shearwaters (Puffinus tenuirostris) are one seabird
species that could be exposed to this increasing threat, owing to their foraging range spanning both
hemispheres and several oceans. With their abundance and circum-Pacific migratory range, birds that
feed by surface-seizing, such as Short-tailed Shearwaters, can be considered potential indicators of
plastic accumulation in the ocean, an issue of increasing international concern. We recorded a total of
1032 pieces of plastic (weighing 25.3 g) from 171 dead Short-tailed Shearwater chicks from Clifton
Beach, Tasmania; there was an average 148.1 mg and 6.03 pieces of plastic per bird. From this study
we were able to conclude that the presence and amount of plastic, transferred from parents during
feeding, had no significant effect on growth and body morphology of chicks. However, it is a significant
concern, particularly in the greater context of marine pollution on a global scale, that 96% of these
fledgling chicks from a relatively remote area are experiencing plastic marine debris ingestion.
Avian responses to varying intensity of cattle production in Spartina densiflora saltmarshes of
south-eastern South America
Daniel Augusto Cardoni , Juan Pablo Isacch and Oscar Iribarne
Emu – Austral Ornithology 115(1), 12–19
http://www.publish.csiro.au/paper/MU13028.htm
Saltmarshes occur along the coasts of all major continents except Antarctica. These ecosystems are
dominated by a few dominant species of salt-tolerant grasses, such as species of Spartina.
Saltmarshes in South America, as elsewhere, have been significantly modified by anthropogenic
activities, particularly production of livestock. We examined the effect of the intensity of cattle
production on the structure of Spartina densiflora saltmarsh vegetation, and how these changes
affected the richness and composition of their bird populations and the abundance of nests. The study
assessed three levels of intensity of cattle production and burning: high, low and none. Cattle
production changed the structure of saltmarsh vegetation, and modified the richness, abundance and
composition of the avian community and the abundance of nests. Saltmarshes with low intensity or no
cattle production were inhabited by specialised and threatened birds of tall grasslands. Conversely,
saltmarshes with a high intensity of cattle production were dominated by short grasses bird species.
That avian species diversity does not differ in areas of saltmarsh subject to either low levels of, or no,
production intensity has important implications for management of saltmarsh–grassland communities
for conservation of avian diversity.
Variation in productivity of Grey-faced Petrels (Pterodroma gouldi) with local burrow density
and breeding island
Christopher J. Jones , Philip O’B. Lyver , Catriona J. Macleod , Amy L. Whitehead and Guy J.
Forrester
Emu – Austral Ornithology 115(1), 20–28
http://www.publish.csiro.au/paper/MU14018.htm
For long-lived birds, estimates of how successfully they breed can be effective indicators of
environmental change or responses to management. We used fibre-optic cameras to survey Greyfaced Petrel nesting burrows on four islands off the north-eastern coast of New Zealand for up to four
breeding seasons and followed the fates of 1371 eggs. Daily nest-survival rates declined with
increasing local burrow density across all islands. We found variable overall breeding success rates of
11 28% across the four sites. This variation in productivity between our study colonies may be linked
to differences in the restoration histories of the islands or the presence of other breeding seabirds at
some sites. These differences suggest that data from one location should be used cautiously when
guiding management of the same species elsewhere.
Study of seed dispersal by Emu (Dromaius novaehollandiae) in the Jarrah (Eucalyptus
marginata) forests of south-western Australia through satellite telemetry
Andrew P. Nield , Neal J. Enright and Philip G. Ladd
Emu – Austral Ornithology 115(1), 29–34
http://www.publish.csiro.au/paper/MU13113.htm
The use of advanced technology, such as the global positioning system (GPS), allows scientists to
better-understand the movement and behaviours of organisms in different environments. We used
GPS devices to track the movement of Emus in the Jarrah forests of south-western Australia. As a
large bird that consumes the seeds of many forest species, the Emu plays an important role in seed
dispersal and plant regeneration. We found that the GPS-tagged Emus were capable of travelling
many kilometres during relatively short periods (weeks), avoiding steep slopes and preferring to
remain within the forested areas. These extensive distances covered indicate that the Emu moves
many seeds over long distances throughout the Jarrah forests. From a methodological perspective,
half of our GPS devices detached before 30 days of tracking data could be recorded. Further studies
of Emu movement within forested areas needs to consider device refinement to enable the collection
of additional data.
Evolutionary history of birds across southern Australia: structure, history and taxonomic
implications of mitochondrial DNA diversity in an ecologically diverse suite of species
Gaynor Dolman and Leo Joseph
Emu – Austral Ornithology 115(1), 35–48
http://www.publish.csiro.au/paper/MU14047.htm
The use of DNA sequences to read the footprint of evolution has grown explosively in the last 25
years. In this paper, DNA sequences are used to understand how the present-day genetic diversity of
bird species in southern Australia has been shaped by both environmental forces and the ecology of
the birds themselves. While affirming expectations that species of wetter habitats were isolated
between eastern and western Australia much earlier than species of drier habitats, we also see how
species that move widely in search of food have less genetic structure than more sedentary species.
In addition, this paper also argues the need for changes to how we classify some birds. We are
suggesting that some birds considered as one species until now need to be recognised as two
species. In other cases, we can pinpoint where more work is needed before such a decision can be
made.
The importance of winter-flowering Aloe ferox for specialist and generalist nectar-feeding birds
Timothy R. Kuiper , Diane L. Smith , Milena H. L. Wolmarans , Sara S. Jones , Ross W. Forbes ,
Patrick E. Hulley and Adrian J. F. K. Craig
Emu – Austral Ornithology 115(1), 49–57
http://www.publish.csiro.au/paper/MU14054.htm
In southern Africa, many Aloe species flower in the austral winter, when nectar sources are scarce.
We have followed the changes in the bird population at a stand of Aloe ferox in the Eastern Cape,
South Africa, for five seasons. When the aloes are in flower from June to August, there is a marked
influx of both specialist nectar feeders (sunbirds) and a range of other bird species that feed
opportunistically on nectar. At other times of year these birds are seldom seen at the site. Using
standard point-counts to record both the diversity and numbers of birds, we have found that Malachite
Sunbirds and three different weavers (Ploceus spp.) are the most numerous flower visitors, although
17 other species of bird have also been seen feeding on nectar at this site. For Aloe ferox, the shortbilled weavers and other opportunistic nectar feeders are the important pollinators, whereas the longbilled sunbirds carry very little pollen on their feathers.
Molecular analysis suggests the occurrence of Shy Albatross in the south-western Atlantic
Ocean and its by-catch in longline fishing
Sebastián Jiménez , Alejandro Marquez , Martin Abreu , Rodrigo Forselledo , Alfredo Pereira and
Andrés Domingo
Emu – Austral Ornithology 115(1), 58–62
http://www.publish.csiro.au/paper/MU13105.htm
Albatrosses are killed or injured through by-catch in longline fisheries and by collisions with warp
cables in trawl fisheries. Here we document the species of a sample of 29 shy-type albatrosses killed
as fisheries by-catch to confirm the observation that White-capped Albatrosses (Thalassarche steadi)
are the dominant shy-type albatross in the south-western Atlantic Ocean and exposed to the pelagic
longline fishery there. Using genetic analyses, we found that 28 specimens were White-capped
Albatrosses. There is no doubt that the White-capped Albatross, which is a regular visitor to
Uruguayan waters, is the predominant shy-type albatross in the south-western Atlantic. However,
these analyses also suggested that the remaining bird was a Shy Albatross (T. cauta). This result
indicates the possibility that a small proportion of shy-type albatrosses in this region could be Shy
Albatross but further analysis is required to confirm this.
Variation in innate immune function during incubation, chick-rearing and moult in Little
Penguins (Eudyptula minor)
Jessica K. Evans , Peter Dann and Theresa Frankel
Emu – Austral Ornithology 115(1), 63–71
http://www.publish.csiro.au/paper/MU13077.htm
A functional and robust immune system is essential for maintaining the ability to combat diseases.
Stresses caused by changed environmental conditions or food availability, as well as those originating
in birds through their natural annual cycles and habitats, can seriously reduce immune function. We
assessed the functionality of the immune system of Little Penguins during their main periods of stress
– moulting, egg laying and chick-rearing – using blood samples. The test showed that during late
chick-rearing, when food requirements are at their highest, and during egg incubation, when Little
penguins do not require as much food and are exposed to greater levels of environmental
contamination, the bacteria E. coli were not destroyed by blood immune factors. Results such as these
can show when susceptibility to diseases is likely to pose the greatest risk to penguins.
Nest-spacing, not human presence, influences the breeding of Chimango Caracaras (Milvago
chimango) in a peri-urban reserve
Claudina Solaro and José Hernán Sarasola
Emu – Austral Ornithology 115(1), 72–75
http://www.publish.csiro.au/paper/MU14038.htm
Urban development has heavily transformed many natural environments around the world and some
bird species seem to be tolerant to these changes. The chimango caracara (Milvago chimango) is one
of the most common and abundant birds of prey in southern South America usually found in towns
and cities. We studied the breeding biology of chimango caracaras in a peri-urban zone in central
Argentina to evaluate the spatial arrangement of nests and the reproductive response of this species
to human disturbances. We found that chimango caracara nested in a dense colony and that a
relatively low reproductive output was exhibited by this species. However, such low reproductive
success was not explained by human presence in our study area. Rather, the proximity of co-specific
nests (i.e. the relatively small distance between neighbouring nests) had greater negative effects on
individual breeding performance than human presence. Our results show that chimango caracaras are
able to breed in highly human-modified environments. However, several aspects of chimango
caracaras’ behaviour and ecology in urban landscapes may be determined by anthropogenic
pressures that ultimately drive their fitness in these modified habitats.
Biparental nest-attendance in Chilean Swallows (Tachycineta meyeni) breeding in Ushuaia,
Argentina
Emilie A. Ospina , Caren B. Cooper , Marcela Liljesthröm , Daniel R. Ardia and David W. Winkler
Emu – Austral Ornithology 115(1), 76–79
http://www.publish.csiro.au/paper/MU14036.htm
Avian embryos require consistent high temperatures to develop properly. Providing these high
temperatures through incubation is an energetically demanding activity. Thus adult birds balance their
energy needs with the thermal needs of the eggs. In a population of Chilean swallows nesting in a cold
region, the southern tip of Tierra del Fuego, Ushuaia, Argentina, we video documented the incubation
behaviour of male and female parents. We installed small cameras and temperature probes into the
nests of three pairs of swallows and discovered that in each, the male bird assisted to some degree in
the incubation of the eggs within the nest. Our interpretation of the video and temperature data is that
one bird (the female) actively provides heat to the eggs, raising their temperature well above ambient,
while a second bird (the male) attends the eggs to decrease the rate at which they cool during the
minutes that the female is away from the nest to forage. This study is the first to document male
incubation behaviour in the Chilean swallow.
Relationship between pest birds and landscape elements in the Pampas of central Argentina
Mariano Codesido , Emmanuel Zufiaurre and David Bilenca
Emu – Austral Ornithology 115(1), 80–84
http://www.publish.csiro.au/paper/MU13110.htm
In agroecosystems, some bird species may become abundant and cause problems as agricultural
pests. But why is that so? What are the elements in the landscape that make such species abundant?
It has been postulated that a mosaic landscape of crops and wooded patches are associated with an
increase in the numbers of pest birds in agricultural landscapes. We chose to investigate this
relationship in the Pampas of Argentina, an extensive and formerly treeless grassland region that has
become one of the largest agricultural regions of the world. Recently, woodlands of exotic tree species
have self-established along riparian zones and roadsides, and patches of trees have also been
planted near rural buildings and cattlelots. We estimated the abundance of four species of birds that
are considered pest species in this region: Eared Dove, Monk Parakeet, Picazuro Pigeon and Spotwinged Pigeon. We found that these pests species in the study area respond more to the presence of
woodlots rather than to the presence of croplands in the landscape. These results have practical
implications, suggesting that management of woodlots of exotic trees may providean effective method
of control of pest-bird species in the Pampas of Argentina.
Book Reviews
AN EYE FOR NATURE: THE LIFE AND ART OF WILLIAM T. COOPER
By Penny Olsen
BIRDS OF NEW GUINEA: SECOND EDITION
By Thane K. Pratt and Bruce M. Beehler
http://www.publish.csiro.au/paper/MUv115n1_BR.htm
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