Equivalent whole-body concentrations of 11-ketotestosterone in female and male coral goby Gobiodon erythrospilus, a bidirectional sex-changing fish.

The relationship between whole-body concentrations of 11-ketotestosterone (11-KT) and sexual function was examined in the coral goby Gobiodon erythrospilus, a bi-directional sex-changing fish. 11-KT occurred in both female and male G. erythrospilus, but levels were not always higher in males than in females within heterosexual pairs, and were not related to the stage of gonadal development of individual fish. These results suggest that comparable 11-KT levels in both sexes may allow serial adult sex change to take place in bi-directional sex-changing species, such as Gobiodon spp.

Patterns of movement and seed dispersal of a tropical frugivore.

Movement is a fundamental feature of vertebrate behavior and can modify processes within populations and communities. Because tropical avian frugivores disperse seeds of many plant species, the temporal and spatial patterning of their movement will influence seed distribution within a habitat. To date, little is known about movement patterns of these birds. Here we consider the movement of an understory frugivore, Mionectes oleagineus. Movements of 16 non-breeding females were monitored using continuous radio-telemetry to provide a general description of movement patterns and to examine the fractal geometry of the spatial component of movement. Most movements were of short distance and duration, with the frequency distributions of both measures strongly skewed to the left. Over the range of measurement scales considered, the fractal dimension of M. oleagineus's movement increased with increasing measurement scale up to ca.100 m, whereafter it appeared to flatten out. We combined movement data with M. oleagineus gut-passage rates for seeds of six plant species to predict seed shadows. Estimated seed shadows were leptokurtic for four of the six plant species, with median dispersal distances for all species from 42 to 56 m. Dispersal distances were of the order of reported pollen dispersal distances, suggesting that even small seed dispersers like M. oleagineus can provide significant dispersal for plant genotypes. Gut-passage rate appears to determine the shape of the seed shadow, while movement determines dispersal scale.

Use of medetomidine for capture and restraint of cassowaries (Casuarius casuaris).

OBJECTIVE: To examine the use of medetomidine for the sedation of captive and wild cassowaries (Casuarius casuarius). DESIGN: Clinical evaluation after administration of medetomidine by IM injection. PROCEDURE: Nine captive and two wild birds were chemically restrained, with the drug being administered by dart to 10 birds and hand injected to one. Doses of 0.26 to 0.31 mg/kg IM provided light sedation sufficient to allow approach and limited handling. Doses of 0.38 to 0.54 mg/kg IM provided heavy sedation adequate for full clinical examination. Body weights were estimated in six birds and measured in five birds and ranged from 40 to 66 kg. Sternal recumbency occurred in six birds, three in each dose range. In nine birds sedation was reversed with atipamezole at a dose of 15 to 80 mg/kg IM, which produced a return to alertness in 40 to 139 min. Forceful sneezing occurred during recovery in three birds. CONCLUSION: Medetomidine is a safe and reliable alternative to manual restraint in cassowaries.

Bryophyte dispersal by flying foxes: a novel discovery.

This research provides the first evidence of dispersal of bryophytes and associated microorganisms through ingestion by a highly mobile vertebrate vector, the spectacled flying fox (Pteropus conspicillatus). Bryophyte fragments were found in faeces collected at four P. conspicillatus' camps in the Wet Tropics bioregion, northeastern Australia. These fragments were viable when grown in culture; live invertebrates and other organisms were also present. Our study has significantly increased understanding of the role of flying foxes as dispersal vectors in tropical forests.