Ground Dwelling Ants as Surrogates for Establishing Conservation Priorities in the Australian Wet Tropics

This study aims to identify a set of areas with high biodiversity value over a small spatial scale within the Australian Wet Tropics. We identified sites of high biodiversity value across an altitudinal gradient of ground dwelling ant communities using three measures of biodiversity. The three measures considered were estimated species richness, complementarity between sites and evolutionary history. The latter measure was derived using the systematic nomenclature of the ants to infer a surrogate phylogeny. The goal of conservation assessments could then be achieved by choosing the most diverse site combinations. This approach was found to be valuable for identifying the most diverse site combinations across an altitudinal gradient that could ensure the preservation of terrestrial ground dwelling invertebrates in the Australian Wet Tropics

Ground Dwelling Ants as Surrogates for Establishing Conservation Priorities in the Australian Wet Tropics

This study aims to identify a set of areas with high biodiversity value over a small spatial scale within the Australian Wet Tropics. We identified sites of high biodiversity value across an altitudinal gradient of ground dwelling ant communities using three measures of biodiversity. The three measures considered were estimated species richness, complementarity between sites and evolutionary history. The latter measure was derived using the systematic nomenclature of the ants to infer a surrogate phylogeny. The goal of conservation assessments could then be achieved by choosing the most diverse site combinations. This approach was found to be valuable for identifying the most diverse site combinations across an altitudinal gradient that could ensure the preservation of terrestrial ground dwelling invertebrates in the Australian Wet Tropics

FIGURES 19 – 22 in A second species of Oristicta Tillyard (Odonata: Isostictidae)

FIGURES 19 – 22. Oristicta filicicola Tillyard, male, anal appendages, dorsal: (19 – 20) from Iron Range; (21 – 22) from Lizard Island. Photos by John Martin

FIGURES 34 – 35 in A second species of Oristicta Tillyard (Odonata: Isostictidae)

FIGURES 34 – 35. Paratype female of Oristicta rosendaleorum sp. nov. (QMT 202662): (34) wings; (35) base of hindwing. Photos by Geoff Thompson

Foraging ecology of three species of hipposiderid bats in tropical rainforest in north-east Australia

We studied the foraging ecology of three species of hipposiderid bats - Hipposideros diadema (mean forearm length: 82 mm), H. cervinus (47 mm) and H. ater (41 mm) - in tropical, lowland rainforest in north-east Queensland, Australia. H. diadema foraged by perching within gaps and flying out to intercept slow-flying insects. The two smaller species typically foraged during flight, in undisturbed forest and gaps, and captured insects by aerial hawking. Seven arthropod taxa were identified in faeces of H. cervinus, with Coleoptera and Lepidoptera being present in most faeces. Percentage volume of moth scales was generally low: 35 of 60 faeces had a volume of 90%. No other taxa were frequently present in faeces of H. ater. Differences in foraging ecology between H. diadema and the smaller species were related to its large size and low manoeuvrability. The dietary differences we found between H. ater and H. cervinus were unexpected, because both species have high-frequency echolocation calls (160-164 and 144-145 kHz, respectively), which suggested that both would capture predominantly moths. Our data show that pairs of hipposiderid species with only small differences in call frequencies may consume different prey taxa; however, we contend that dietary variation is more likely to result from differences in body size, wing morphology, and tooth, jaw, and cranial morphology

Bat predation on eared moths: A test of the allotonic frequency hypothesis

Many species of moths (Lepidoptera) possess ears which enable them to hear the echolocation calls of bats and avoid predation. The range of best hearing of eared moths is to frequencies usually between 20 and 50 kHz; therefore, bats with calls above or below these frequencies are predicted to capture eared moths more frequently than other bats. This prediction is the basis of the allotonic frequency hypothesis. We conducted a field test of the hypothesis using three species of flutter-detecting bats which capture flying insects. The species were diadem leafnosed bat Hipposideros diadema (call frequency 55-58 kHz), eastern horseshoe bat Rhinolophus megaphyllus (67-71 kHz) and dusky leafnosed bat H. ater (160-164 kHz). Eared moths represented only 7.2% of individuals among prey remains of H. diadema. Moths dominated the diet of both R. megaphyllus and H. ater, being present in almost all faeces and representing the vast majority of prey remains. However, R. megaphyllus captured predominantly non-eared moths (Anthelidae, Lasiocampidae, Hepialidae) or Gelechioid moths, a superfamily which has not been tested for hearing. By contrast, H. ater fed mostly on eared moths, predominantly members of the family Noctuidae. Eared moths made up 91.7% and 82.5% of all moths captured by H. ater at two sites. The data show that the incorporation of eared moths in the diet was much higher in the bat species, H. ater, with a call frequency well above the range of best hearing of moths. This result supports the allotonic frequency hypothesis. Our study indicates that flutter-detecting bats could have imposed selective pressures on moths during the evolution of moth hearing

The Tribe Dufouriini (Diptera: Tachinidae: Dexiinae) recorded from Australia with the description of two new species

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Vertebrate diet decreases winter torpor use in a desert marsupial

One of the energetic benefits of daily torpor over prolonged hibernation is that it enables animals to regularly forage and, therefore, replenish food reserves between bouts of torpor. However, little is known about the diet of predators undergoing torpor or whether differences in prey composition among individuals influence torpor characteristics. Here, we test the hypothesis that prey composition affects winter torpor use and patterns of a population of carnivorous marsupial, the brush-tailed mulgara ('Dasycercus blythi'), in the Great Sandy Desert, Australia. Mulgaras in the study population captured a wide range of prey including vertebrates (mammals, reptiles, birds), seven insect orders, spiders and centipedes. The proportion of vertebrates in the diet was negatively correlated with both frequency of torpor use and maximum bout duration. This variation in torpor use with diet can be explained by the higher energetic content of vertebrates as well as their larger size. Even assuming uniform intake of prey biomass among individuals, those that subsisted on an invertebrate-dominated diet during winter apparently suffered energetic shortages as a result of the scarcity of invertebrate taxa with high energy content (such as insect larvae). Our study is the first to demonstrate a link between diet composition and daily torpor use in a free-ranging mammal

Why is the marsupial kaluta, 'Dasykaluta rosamondae', diurnally active in winter: Foraging advantages or predator avoidance in arid northern Australia?

The majority of animals have a specific activity rhythm over the 24 h daily cycle such that they can be categorised as either diurnal or nocturnal. This stability creates interest in understanding species that can invert their activity rhythm. The kaluta, 'Dasykaluta rosamondae', a small dasyurid marsupial endemic to northern arid Australia, is one such species. In contrast to most other dasyurid species and in fact most small mammals, the kaluta is almost exclusively diurnal in winter. To assess the potential benefits of diurnal activity we examined the diet and assessed potential predators and competitors. We identified 33 food categories including four classes of invertebrates, three classes of vertebrates and plant material. Diet was dominated by Coleoptera (beetles, 26.7% volume) and Formicidae (ants, 25.0% volume). We found no evidence that the prey base of kalutas differed as a consequence of diurnal activity. Likewise, diurnal foraging was probably not driven by competition. A likely explanation of diurnal activity in winter in this species is that it both allows temporal separation in activity from a significant predator, the brush-tailed mulgara, 'Dasycercus blythi', and reduces thermoregulatory foraging costs