Cooperative Territorial Defense in the Australian Magpie,Gymnorhina tibicen (Passeriformes,Cracticidae), a Group-living Songbird

Comparison of populations that vary in cooperative behavior can point to factors that influence the evolution of cooperative breeding. In this paper we study cooperative territorial defense in two populations of the Australian magpie. These populations differed in social organization; in New Zealand group breeding was the norm and in Queensland simple pair breeding was the norm. We used caged territorial intruders to examine experimentally the participation of males, females, and juveniles in synchronous territorial defense. Within a population in Queensland and a population in New Zealand, adult males and females participated in cooperative defense significantly (p < 0.05 at least) more often together than alone. Between populations, Queensland pairs differed significantly (p < 0.01 at least) from New Zealand pairs in the level of response. As group size increased, percapita input in defense decreased in both populations. We discuss the importance of synchronous defense as a cooperative behavior in this species.     

Molecular characterization of native Australian trypanosomes in quokka (Setonix brachyurus) populations from Western Australia

The quokka, Setonix brachyurus, is a vulnerable, small marsupial endemic to Western Australia. Blood samples were collected from quokkas from three different geographical locations; Two Peoples Bay, Bald Island and Rottnest Island. The overall prevalence of trypanosomes by nested PCR at the 18S ribosomal RNA gene was 57.3% (63/110) with prevalences of 91.4%, 85.3% and 4.9% respectively for Two Peoples Bay, Bald Island and Rottnest Island. Phylogenetic analysis conducted on 47 18S PCR positives identified two Trypanosoma copemani genotypes, with T. copemani genotype B, the most prevalent genotype infecting quokka populations from the three locations with an overall prevalence of 51.8% (24/47) compared to 34% for T. copemani genotype A (16/47). The overall prevalence of mixed T. copemani genotype A and B infections was 14.9% (7/47). Phylogenetic analysis of 26 quokka isolates at the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) locus, largely supported the 18S analysis but identified a mixed infection in one quokka isolate (Q4112-4117 from Two Peoples Bay). T. copemani genotype B has previously only been isolated from quokkas and the Gilbert's potoroo whereas T. copemani genotype A has a wide host range and may be pathogenic. Further work is required to determine the clinical impact of T. copemani on marsupial populations.     

Communal roosting in the Magpie (Pica pica)

Summary Why does MagpiesPica pica roost communally rather than solitarily in winter? Most roosts were situated in deciduous trees near water, and they held relatively small numbers of birds. All Magpies roosted communally in winter. Strong winds reduced the height of roost perches, and roosting in leeward conditions increased. Less time was spent at the roost before and following roosting in winter when compared with the autumn and the spring situations. Magpies from high quality territories arrived late in the evening and left early in the morning. Foraging activity increased at the roost as day-length decreased, whereas flying remained constant. Sexual and aggressive behaviour were common in spring. Juveniles were sub-ordinate at the roost. Communal gathering was common at the roost. Several activities occurred frequently either at the pre-roost or at the roost, but aggressive and sexual behaviour had a spatial distribution as expected from the number of birdhours spent in the two sites. Roosting ceased following initiation of nesting activity, but early nesters attended the roost longer than late nesters following start of nest building. Start of breeding was not synchronized within roosts. Predation was rare at the roost and elsewhere in the study area. Roosting seems not to be due to information centre effects, predator avoidance, favourable micro-climate, lack of roost sites, or synchronization of breeding activities. Magpies may monitor the quality of their neighbours including their mating status at the roost. Communal roosting of corvid species seems to be related primarily to the distribution and the abundance of food, species with an unpredictable food supply roosting communally.

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Gemeinsames Übernachten bei der ElsterPica pica

Zusammenfassung Warum ziehen Elstern Gemeinschaftsschlafplätze der Einzelübernachtung vor? Viele Übernachtungsplätze liegen in Laubbäumen am Wasser und werden meist nur von relativ wenigen Individuen benutzt. Im Winter übernachteten jedoch alle Elstern in größeren Scharen (Abb. 1). Starker Wind verringert die Höhe der Sitzplätze und begünstigt leewärts gelegene. Vor und nach dem Übernachten waren die Elstern im Winter weniger lange Zeit answesend als im Frühjahr und Herbst (Abb. 6). Elstern aus Revieren hoher Qualität kamen abends später und flogen morgens früher wieder ab (Abb. 7, 8). Nahrungssuche am Übernachtungsplatz nahm mit abnehmender Tageslänge zu; Flugaktivität blieb konstant. Im Frühjahr waren Anzeichen von Aggressivität und Sexualverhalten häufig. Juv. nahmen an Übernachtungsplätzen niedrigere Rangstellungen ein. Schwarmbildung war häufig. Verschiedene Aktivitäten waren häufig entweder vor oder am Übernachtungsplatz festzustellen, doch Aggressiv- und Sexualverhalten konzentrieren sich meistens auf Plätze außerhalb. Nach Beginn des Nestbaus wurde der gemeinsame Übernachtungsplatz nicht mehr aufgesucht (Abb. 12), doch blieben Frühbrüter relativ länger als Spätbrüter gemessen am Stand des Brutgeschäfts. Innerhalb einer Übernachtungsgesellschaft verlief der Beginn des Nestbaus nicht synchron. Der Feinddruck am Schlafplatz wie im übrigen Untersuchungsgebiet war sehr gering. Gemeinsames Übernachten scheint keine Bedeutung als Informationszentrum oder für Verringerung der Feindeinwirkung zu besitzen, noch ist es wegen günstigen Mikroklimas, des Fehlens geeigneter Übernachtungsplätze oder als Mittel der Synchronisation des Brutgeschäftes erklärbar. Elstern prüfen vielleicht die Qalität ihrer Nachbarn und ob sie verpaart sind. Gemeinsames Übernachten scheint bei Corviden in erster Linie mit der Verteilung und Menge der Nahrung zusammenzuhängen: Arten mit einem nicht vorhersagbaren Nahrungsangebot übernachten gemeinsam.

     

Chromosome numbers of Western Australian species ofVillarsia (Menyanthaceae)

Chromosome numbers are reported for eight of the nine Western AustralianVillarsia species.Villarsia albiflora, V. calthifolia, V. capitata, V. congestiflora, V. lasiosperma, V. latifolia, andV. violifolia are diploid with n=9. Five populations ofV. parnassiifolia are diploid and three are tetraploid (n=18). The morphological, ecological, and breeding-system diversity of the Western Australian species is largely not associated with the tetraploidy or hexaploidy that characterizes otherVillarsia species in eastern Australia and South Africa. The majority of Western AustralianVillarsia species are restricted to the high rainfall zone of southwestern Western Australia, where favorable climatic and edaphic conditions may have existed since mid-late Tertiary times.     

A new species of Darwinia (Myrtaceae) from Western Australia

A new species of Darwinia, D. divisa is described. The species is unique in the genus in having divided prominent calyx lobes and densely hairy floral tube. The species has not been re-collected since the type and only collection in 1965.     

A new genus of Syllidae (Polychaeta) from Western Australia

During a study carried out on the subfamily Exogoninae (Syllidae) from Australia, several specimens of a new genus and species were found in samples of dead coral substrate from Western Australia. They have long palps, fused except for a terminal notch, long median and two short lateral antennae, a single pair of short tentacular cirri, and short dorsal cirri, somewhat longer than the parapodial lobes. These characters resemble those of the genus Exogone Örsted, 1845. However, all these appendages are articulated. The chaetae are very similar to those of several species of Syllis Lamarck, 1818, having coarse spines on the margin of compound chaetal blades and truncated dorsal simple chaetae. Furthermore, the pharynx begins in chaetiger 3, posterior to the peristomium, as in many species of the genus Syllis; this condition does not occur in any described species of Exogone. The new genus is provisionally proposed to belong to the subfamily Syllinae, although it has some characters typical of the Exogoninae. Examination under the SEM shows another peculiar feature, the nuchal organs are distinctly laterally located. Within the Syllinae, only Paratyposyllis Hartmann-Schröder, 1962 has a single pair of tentacular cirri, but in that genus, the palps are only basally fused.     

Phylogeography and divergence in the chloroplast genome of Western Australian Sandalwood (Santalum spicatum)

Western Australian sandalwood (Santalum spicatum) is widespread throughout Western Australia across the semiarid and arid regions. The diversity and phylogeographic patterns within the chloroplast genome of S. spicatum were investigated using restriction fragment length polymorphism analysis of 23 populations. The chloroplast diversity was structured into two main clades that were geographically separated, one centred in the southern (semiarid region) and the other in the northern (arid) region. Fragmentation due to climatic instability was identified as the most likely influence on the differentiation of the lineages. The lineage in the arid region showed a greater level of differentiation than that in the southern region, suggesting a higher level of gene flow or a more recent range expansion of sandalwood in the southern region. The phylogeographic pattern in the chloroplast genome is congruent with that detected in the nuclear genome, which identified different genetic influences between the regions and also suggested a more recent expansion of sandalwood in the southern region.     

Subterranean archipelago in the Australian arid zone: mitochondrial DNA phylogeography of amphipods from central Western Australia

In 1998, a unique subterranean ecosystem was discovered in numerous isolated calcrete (carbonate) aquifers in the arid Yilgarn region of Western Australia. Previous morphological and genetic analyses of a subterranean water beetle fauna suggest that calcrete aquifers are equivalent to closed island habitats that have been isolated for millions of years. We tested this hypothesis further by phylogeographic analyses of subterranean amphipods (Crangonyctoidea: Paramelitidae and Hyalidae) using mitochondrial DNA sequence data derived from the cytochrome oxidase I gene. Phylogenetic analyses and population genetic analyses (samova) provided strong evidence for the existence of at least 16 crangonyctoid and six hyalid divergent mitochondrial lineages, each restricted in their distribution to a single calcrete aquifer, in support of the 'subterranean island (archipelago) hypothesis' and extending its scope to include entirely water respiring invertebrates. Sequence divergence estimates between proximate calcrete populations suggest that calcretes have been isolated at least since the Pliocene, coinciding with a major aridity phase that led to the intermittent drying of surface water. The distribution of calcretes along palaeodrainage channels and on either side of drainage divides, have had less influence on the overall phylogeographic structure of populations, with evidence that ancestral crangonyctoid and hyalid species moved between catchments multiple times prior to their isolation within calcretes. At least two potential modes of evolution may account for the diversity of subterranean amphipod populations: dispersal/vicariance of stygobitic species or colonization of calcretes by surface species and independent evolution of stygobitic characteristics.     

The structure of the seed in some Western Australian species of the genus Hibbertia (Dilleniaceae)

The internal structure of the seed was studied for four Western Australian species of the genus Hibbertia (Fam.: Dilleniaceae). The principal mechanical layer of the seed coat is the endotesta. The large cells of the endotesta are heavily cutinized in potentially viable seeds of all examined species. However, results for H. hypericoides show that the cells of the endotesta are distinctly less cutinized in non-viable seeds. The tegmen consists of only one layer which is spirally thickened. Remains of the nucellus enclose the endosperm. The endosperm is rich in both starch and lipids, and the embryo is underdeveloped and minute.     

Coxiella burnetii in Western Barred Bandicoots (Perameles bougainville) from Bernier and Dorre Islands in Western Australia

The aim of this work is to investigate the presence of Coxiella burnetii in Perameles bougainville and their ticks on two islands off Western Australia. Haemaphysalis humerosa, Haemaphysalis ratti, and Haemaphysalis lagostrophi were collected from P. bougainville on Bernier and Dorre Islands from 2005 to 2007; only Amblyomma limbatum was collected from humans over the same interval. One of 13 tick samples and 1 of 12 P. bougainville fecal samples were positive for C. burnetii DNA using quantitative polymerase chain reaction. DNA fragments had >99% similarity to published C. burnetii sequences. Three of 35 P. bougainville sera tested positive for anti-C. burnetii antibodies using enzyme-linked immunosorbent assay. C. burnetii was found in P. bougainville feces and a H. humerosa tick on Dorre Island and Bernier Island, respectively. This is the first reported use of enzyme-linked immunosorbent assay for screening of P. bougainville sera. The risk of zoonotic Q fever infection for human visitors to these islands is considered relatively low, however, appropriate precautions should be taken when handling western barred bandicoots, their feces and their ticks on Bernier and Dorre Islands.     

Mosquito (Diptera: Culicidae) fauna in inland areas of south-west Western Australia

Abstract  Previously existing sources of data regarding mosquitoes in inland areas of south-west Western Australia are few and qualitative in nature. This is the first attempt to quantitatively investigate mosquito fauna in this region. The existing data are reviewed and compared with the results of the quantitative surveys presented in this paper. Temporal comparisons appear to indicate that mosquito community structure in the region may have changed since the initial surveys in the 1950s from a combination of freshwater-breeding species towards a strong dominance of Aedes camptorhynchus (Thomson), a major vector of Ross River virus in southern Australia. It is speculated that this shift may have been brought about by the increasing area and severity of dryland salinity in the region over the last century, and also may increase the potential for Ross River virus disease transmission.