The Capricorn Yellow Chat (Meliphagidae: Epthianura crocea macgregori) is a poorly known, endangered passerine
of coastal north-eastern Australian wetlands. Recent research has highlighted the need for evidence based management
and that recovery programmes may be hampered by a lack of sound ecological knowledge. Capricorn Yellow Chats
were found at 15 sites near Rockhampton between Broad Sound and the Fitzroy River delta in the south. Overall,
suitable habitat was limited with an area occupied of about 6 000 ha, confirming the need for careful management.
Habitat may be typified as grass-sedge wetlands or tall supratidal saltmarshes that are temporarily flooded, with pools
becoming brackish to hypersaline as they dry. Over 96% of sightings were on coastal plains formed by marine
sedimentation processes, most without current tidal influence, and many less than 5 m above sea level. The remaining
4% were associated with alluvial-formed plains, but only where these bordered existing marine plain sites; suggesting
a preference for marine plain habitats, possibly reflecting structural differences and foraging preferences (marine plains
tend to be more open due to the presence of salt-tolerant samphire vegetation). Sea level rise was identified as a
major threat to the subspecies with chat sightings at most sites averaging less than 2 m above current highest
astronomical tidal influence, and sites becoming tidal or with regular storm surge influence under future modest predicted
sea level rise scenarios of 0.5 m by 2100. Most sites had some form of banking to reduce tidal influence and promote
freshwater pasture grasses for cattle production. The site supporting most chats had small banks that allowed floods
to flow around them, maintaining connectivity with the downstream marine systems. This study contributes to baseline
information essential to the evaluation of any future management interventions; thus avoiding the pitfalls hampering
much of the global conservation efforts directed at threatened species.
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The spur-throated locust Nomadacris guttulosa (Walker) was reared under laboratory conditions for the first time. Females were larger and heavier than males and had 1-3 additional instars. Eye stripe number was the most useful indicator of instar number. Male nymphs changed colour from green to brown on average 1 instar earlier than females. Ratios of adult hind femur length/head capsule width and fore wing lengthlhind femur length were independent of sex. The ratios obtained were similar to those expected of the extreme solitarious phase of other locusts.The duration of the nymphal stage decreased with temperature; 137 d at 24'C; 62 d at 3 1°C and 60 d at 32"/39"C. Food type had no effect except at 27°C and 35% relative humidity (RH), where first-instar nymphs fed daily on cut wheat seedlings failed to survive, but did so on wheat growing in tubes.Under continuous illumination and 35-48% RH, oviposition commenced earlier at 32'/39'C than at 31°C.
The critically endangered Capricorn yellow chat (CYC) is endemic to coastal central Queensland on marine plains where it occurs in three areas, numbering <300 birds. Recent industrial expansion in the region has increased the threat to the CYC. To assist management of the subspecies, a phylogeographical evaluation of the CYC using mitochondrial DNA was undertaken. We found no genetic diversity within, nor genetic divergence between, the two areas at the northern and southern extremes of their current distribution, and only slight morphological differences. These findings suggest that the two groups of CYC represent daughter populations of an ancestral population that was affected by a genetic bottleneck in the recent past. Implications for conservation of the subspecies could be increased vulnerability to environmental change. A preliminary evaluation of the divergence between the CYC and its nearest subspecies, the widespread inland yellow chat, indicate a time to the most recent common ancestor of 215 000 years or less. This timespan overlaps two periods of glacial aridity during which xeric habitats used by yellow chats for breeding, such as semiarid and arid swamps, may have expanded, allowing colonisation of the coastal marine plains. CYCs may represent a relictual population from a previously more xeric era that has subsequently become isolated as the region became wetter following glacial maxima.
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