Pardalote

Abstract: Three species of pardalote co-occur only in eastern Tasmania. We examined habitat selection and foraging ecology of the three species, Pardalotus punctatus, P. quadragintus and P. striatus, in that area. Overlap and similarity between all three species was high in both foraging activity and habitat choice. All three species are specialized leaf-gleaners and favoured Eucalyptus virninalis forests. The distributions of the species were related to Eucalyptus species diversity, species of Eucal.vptus dominant, disturbance, and number of hollows and overmature trees at sites. It is suggested that there is substantial interaction between P. quadragintus and P. striatus and that this may affect the distribution and abundance of the restricted and declining P. quadragintus.

Abstract: The high levels of polymorphism and allelic diversity which characterise genes in the major histocompatibility complex (MHC) are thought to be generated and maintained through the combined effects of different evolutionary processes. Here, we characterised exon 2 of the MHC class II β genes in two congeneric passerine species, the spotted (Pardalotus punctatus) and striated pardalote (Pardalotus striatus). We estimated the levels of allelic diversity and tested for signatures of recombination, gene conversion and balancing selection to determine if these processes have influenced MHC variation in the two species. Both species showed high levels of polymorphism and allelic diversity, as well as evidence of multiple gene loci and putative pseudogenes based on the presence of stop codons. We found higher levels of MHC diversity in the striated pardalote than the spotted pardalote, based on the levels of individual heterozygosity, sequence divergence and number of polymorphic sites. The observed differences may reflect variable selection pressure on the species, resulting from differences in patterns of movement among populations. We identified strong signatures of historical balancing selection, recombination and gene conversion at the sequence level, indicating that MHC variation in the two species has been shaped by a combination of processes.

Abstract: Traditional methods of examining the nest contents of burrow-nesting birds have often been destructive, expensive, and/or limited to large-bodied species. Here we present details of a small, efficient, and inexpensive “burrowscope” designed for examining the nest tunnels of very small birds. The burrowscope consists of a tiny (16 mm × 22 mm) video camera and infrared light-emitting diodes, mounted on the end of flexible conduit (20-mm diameter) that houses a live video feed to a small, hand-held monitor display. In total, the burrowscope is only 22 mm wide at its widest point, weighs approximately 900 g, and was built for less than US $400. The burrowscope was tested in the field and could be used at 99.8% of Rainbow Bee-eater (Merops ornatus) nests and 100% of Spotted Pardalote (Pardalotus punctatus) nests (one of the world's smallest burrow-nesting birds). The accuracy of the burrowscope was evaluated by excavating a nest access hole at a sub-sample of Rainbow Bee-eater nests. The burrowscope e...

Abstract: Fifty-eight nests of the Eastern Striated Pardalote Pardalotus ornatus and the Spotted Pardalote P. punctatus were studied in north-eastern Victoria. P. ornatus nests in the subsoil where it is unprotected by surrounding vegetation. The entrances of its nests face south, lessening penetration by sunlight. P. punctatus nests in the topsoil where the nesting burrow is shaded by vegetation. The size of the entrance of nests of P. ornatus probably decreases with increasing altitude. The two species are probably influenced in choosing sites of nests by microclimate, predation and ease of construction.