ABSTRACT In 2012, one of us observed an adult male peninsula dragon ( Ctenophorus fionni ) predate a juvenile conspecific. This was noteworthy as we understood peninsula dragons to be primarily insectivorous and it prompted us to investigate cannibalism more generally using a systematic, comprehensive review of the literature. Cannibalism has never been reported in any wild, natural‐living Australo‐Papuan (i.e., Amphibolurine) agamid, except in the peninsula dragon. There are now three records of cannibalism in the peninsula dragon, all from populations of the central form. This raises the possibility that peninsula dragons, or certain populations thereof, may be unusually predisposed to cannibalism. However, the current data available are too sparse to draw firm conclusions and we encourage anyone with observations of cannibalism to publish them.
ABSTRACT The bait polychaete Diopatra aciculata is commercially farmed in Australia and is collected as bait in several South African estuaries. Despite its widespread use, the species' geographic origin remains uncertain, hindering management efforts within sensitive estuarine ecosystems. Mitochondrial Cytochrome Oxidase subunit I (mtCOI) data and ddRAD‐generated single‐nucleotide polymorphisms (SNPs) were used to gain insight into the origin and genetic diversity of D. aciculata. A total of 204 individuals were collected from an aquaculture farm in Australia and the Knysna, Keurbooms, and Swartkops Estuaries in South Africa. The mtCOI analyses supported the monophyly of D. aciculata and revealed lower genetic diversity in the South African population compared to the Australian population. Both marker sets revealed significant genetic differentiation between the continental populations that are naturally isolated by the Indian Ocean basin. The SNP dataset revealed low intrapopulation genetic diversity for both the Australian and South African populations. The discordant genetic diversity findings between the mtCOI and SNP datasets may be attributed to the differences in the evolutionary rate of the two marker systems. In addition, the low genomic diversity observed in the SNP dataset is consistent with the effects of captive breeding in the Australian aquaculture population; consequently, the effect of sampling bias cannot be excluded. However, the mtCOI signal of reduced diversity in South Africa is consistent with an introduced population and both mtCOI and SNP‐based RASP analyses recovered Australian samples in a basal position, suggesting Australia as the plausible origin. This highlights the need for precautionary conservation efforts to prevent further spread.
ABSTRACT Molecular sexing is a widely used approach for identifying the sex of monomorphic birds, but existing primers often target relatively large products that are difficult to amplify from highly degraded DNA. In this study, we developed a new primer set (voEP_F/voEP_R/P2) based on allele‐specific polymerase chain reaction (ASPCR) to facilitate the sexing of emperor penguins ( Aptenodytes forsteri ) using non‐invasively collected guano. Our assay targets short sequences within a conserved exon of the chromodomain helicase DNA binding 1 ( CHD1 ) gene and can therefore be used with a broad range of sample types. We compared the performance of our new primer set in both plucked feathers and guano to the commonly used intron‐based sexing primers (2550F/2718R and P8/P2) and evaluated its sensitivity through a cross‐factorial fragmentation and dilution experiment of synthetic CHD1 templates. We then independently validated the accuracy of our assay in a small subset of feather samples using whole‐genome sequencing (WGS) data. Although P8/P2 was highly effective compared to 2550F/2718R for sex determination in emperor penguins, it was less reliable when used with guano samples. In contrast, the voEP primers consistently yielded higher amplification success and showed greater analytical sensitivity across both feathers and guano. Sequence alignments of CHD1 from multiple penguin species revealed conservation of the primer‐binding sites, suggesting that the newly designed primers can potentially be used with other Spheniscids. Our results demonstrate that the voEP assay is a robust and reliable alternative method for sex identification in penguins and may provide a solution for sexing with lower‐quality genetic samples.
ABSTRACT Novel species interactions between resident and range shifting species in response to warming are posing challenges for conservation and management. This is especially the case when major predatory species are involved, as seen in the appearance of a mixed species outbreak of coral‐eating crown‐of‐thorns sea stars Acanthaster cf. solaris (As) and the lesser‐known Acanthaster brevispinus (Ab) in the tropical to subtropical transition zone in eastern Australia. The outbreak consisted of reproductively mature animals, and we investigated the potential for cross‐species hybridisation in fertilisation experiments across a range of sperm concentrations to sperm limitation conditions (106–102 sperm mL−1). Fertilisation was successful in all combinations of parents (As ♂ × As ♀, Ab ♂ × Ab ♀, Ab ♀ × As ♂, As ♀ × Ab ♂) with successful hybrid crosses in sperm dilutions as low as 102 sperm ml−1. Development in conspecific and heterospecific crosses was similar through the bipinnaria and brachiolaria larval stages to the juvenile. Juvenile hybrids had typical juvenile Acanthaster spp. development with a stellate five‐armed profile post metamorphosis, gaining arms after ~78 days. At no stage did the juvenile hybrids develop the distinctive pink colour trait that is characteristic of Acanthaster cf. solaris juveniles. Our results indicate that hybridisation is not restricted by sperm limitation conditions, with subsequent development of hybrids to the advanced juvenile stage. Our results highlight the potential for hybridisation and species introgression when range shifting species overlap with sister taxa. This may facilitate further range expansion or development of resilient hybrid progeny as a risk to vulnerable high latitude coral communities.
ABSTRACT Climate change is intensifying fire weather globally, increasing land managers' reliance on prescribed burning to reduce fuel loads and mitigate wildfire risk. Yet the direct effects of prescribed fire on threatened wildlife remain poorly understood, partly because individual‐level data on survival and behaviour during fire events are exceptionally rare. We used VHF telemetry and accelerometry to track the survival, space use and diel activity of nine western ringtail possums (Pseudocheirus occidentalis; ngwayir; eight collared, one uncollared joey)—a Critically Endangered arboreal marsupial widely regarded as highly sensitive to fire—through a low‐ to moderate‐severity prescribed burn at Yalgorup National Park, south‐west Western Australia. All nine animals survived direct fire exposure despite several refuge trees being scorched or structurally damaged. Post‐fire, possums relocated an average of 181 m, but movement distances were unrelated to burn severity and possums showed no selection for unburnt habitat, suggesting limited spatial disruption at the home‐range scale. This may partly reflect the predominantly low‐severity nature of the burn (95.7% of the burnt area). Accelerometry revealed suppressed nocturnal activity during smoke exposure and the fire period, with only partial recovery in the days following the burn, indicating measurable sublethal costs even where direct mortality did not occur. We interpret these behavioural responses as potentially consistent with adaptations shaped by long‐term exposure to frequent, low‐severity fire regimes historically associated with Noongar burning on the Swan Coastal Plain. Although based on a small number of individuals at a single site, and a carefully implemented low‐ to moderate‐severity prescribed burn, our findings provide rare empirical evidence that a critically endangered marsupial can survive prescribed fire. These results have implications for how prescribed burning programs are designed and implemented in the context of evolving fire regimes under climate change.
