Pair bonding is a social behaviour observed among many vertebrate lineages, and is often regulated by nonapeptides, such as oxytocin, and neurotransmitters such as dopamine. Much of our understanding of the neurochemical mechanisms underlying pair bonding come from previous research utilising established model species such as prairie voles (Microtus ochrogaster), titi monkeys (Plecturocebus cuperus) and zebra finches (Taeniopygia castanotisi). However, the role of these neurochemicals in reptiles — a group in which pair bonding is rare and less well understood — remains largely unexplored. This study aimed to investigate whether mesotocin (non-mammalian homolog of oxytocin) and dopamine play key roles in regulating pair bonding behaviours in the pair bonding squamate reptile, the sleepy lizard (Tiliqua rugosa). Pharmacological antagonists were used to simultaneously block mesotocin and D1 dopamine receptors, allowing assessment of their combined effects on proximity behaviours. Our results revealed limited changes in pair bonding behaviours between the control and treatment groups, providing minimal evidence supporting a primary role for mesotocin and dopamine regulating pair bonds in sleepy lizards. However, interesting trends emerged, suggesting treatment related differences in pair-dynamics and baseline affiliative behaviour. These findings provide an important foundation for further research into the neuroendocrine systems involved in pair bonding and contributes to the broader understanding of the evolution of pair bonding behaviours across vertebrate lineages.

Understanding geographic variation in vocal signals can reveal population differentiation and inform conservation strategies. In this study, we analysed flight calls from Australian fairy terns (Sternula nereis nereis) across ten breeding colonies in South Australia and Western Australia to assess acoustic divergence between the two sub-populations (southern and western Australia) and evaluate the need for location-specific calls in conservation efforts. Although calls grouped into three different clusters, these did not align with geographic locations. This lack of vocal divergence suggests no reproductive isolation and implies potentially stronger connectivity between the populations than previously believed. Our findings also support the effective use of generic conspecific calls in conservation initiatives.

Kangaroos are the largest bipedal marsupial herbivore to ever evolve, and Australia boasts the widest diversity of species. The widespread retention and use of saltatory locomotion is unique to this lineage and, in larger species, has evolved to be energetically advantageous at higher speeds. This has raised important questions surrounding how this lineage developed its distinctive mode of locomotion, and why similar adaptations in placentals have not followed the same evolutionary progression. However, most gait studies have been conducted in laboratory conditions and with a direct focus on smaller sized species. This has left a gap in our understanding about how these traits function amongst larger species in their natural environment. To address this, we aimed to compare the locomotor patterns (stride parameters) of various Macropodoid species to enhance our understanding of bipedal locomotion in kangaroos. We collected locomotor footage of wild, captive and semi-captive individuals across the three sub-families of Macropodidae. Digitization software was used to quantify gait parameters such as; stride frequency, length and speed, enabling precise analysis of locomotor patterns. Environmental variables such as substrate type was also noted to see if there is any variation in stride pattern within more complex landscapes. We predict that larger kangaroos will have on average a lower stride frequency compared to smaller individuals and stride length will increase with speed. We also expect that substrate type will affect certain gait parameters (I.e., ground contact time and aerial phase). The outcome of this research will contribute to a more comprehensive understanding of gait modulation in free-roaming kangaroos and foster integration between biomechanics and ecology by contextualising biomechanical data within real-world environments.

Ants are often referred to as “the little things that rule the world” because of the critical roles they play as ecosystem engineers and moderators of plant and animal performance through trophic and non-trophic interactions. Here we describe an experimental test of the influence of ants on two other ubiquitous invertebrate groups, spiders and beetles, in an Australian tropical savanna where ant abundance and diversity are exceptionally high. We experimentally suppressed ant abundance by 52-77% through baiting in six plots (each matched with adjacent reference plots) across two sites and documented the impact on spider and beetle assemblages. Ants are both competitors and predators of spiders and beetles, and so we expected ant suppression to result in increases in spider and beetle abundance and richness. However, this largely did not occur even after two years of ant suppression. Such a finding implies that there is limited regulation of arthropod communities by ants in our study system. This contrasts with findings from other ant manipulation experiments showing marked impacts on other arthropods, which is particularly surprising because ant abundance is so high in Australian savannas. More experimental studies are required, but our results suggest that arthropod assemblages in Australian savannas are resilient to large reductions of a ubiquitous group that dominates faunal biomass.