Biology subjects

King, S. L.

Publications and source records attributed to King, S. L..

4 recordsLinked to original sources

bioRxiv2026

Demographic change in an iconic dolphin population driven by habitat degradation following a marine heatwave

Extreme climate events are rapidly reshaping ecosystems and contributing to biodiversity loss, yet their long-term impacts remain poorly understood, particularly in marine systems. In 2011, an unprecedented marine heatwave (MHW) on the west coast of Australia drove declines in habitat-forming plants and across taxa spanning multiple trophic levels. Shark Bay, home to an iconic Indo-Pacific bottlenose dolphin (Tursiops aduncus) population, endured temperatures 3-5{degrees}C above long-term means, triggering catastrophic seagrass loss. Using 20 years (2003-2023) of dolphin photo-identification data, we fitted a Bayesian Hidden Markov Model to estimate annual, age-class specific survival probabilities, abundance and recruitment rate, and their association with MHW-mediated seagrass loss in the western (WSB) and eastern (ESB) gulfs of Shark Bay. Adult survival declined markedly, from 0.99 (0.98-1.00) pre-MHW to 0.85 (0.79-0.90) post-MHW in WSB, and from 0.96 (0.92-0.98) to 0.89 (0.85-0.95) in ESB, remaining below pre-MHW levels for several years, while juvenile and calf survival declined in both gulfs to a lesser extent. Recruitment declined in both gulfs and, although recovery was evident in WSB from 2019 onward, continued to decline in ESB until the end of the study. These sustained demographic declines drove substantial reductions in population growth and abundance in both WSB (39%) and ESB (36%). Demographic changes were associated with seagrass loss, here a proxy for habitat and prey availability, with clearest support for adult survival in WSB and a two-year-lagged recruitment response in ESB. This pathway is likely to operate across diverse ecosystems as climate change drives increasing loss of habitat-forming species. The severity and duration of these demographic impacts illustrate that habitat change can cascade through trophic systems to overwhelm demographic resilience in upper-trophic species. This has negative implications for even long-lived, K-selected species, whose slow demographic recovery may not keep pace with the accelerating frequency and intensity of climate disturbance.

ecology↗

bioRxiv2026

Socially learned call sequences reveal gradual development of higher-order structure

Syntax was long considered to distinguish human language from other vocal systems, with parallels in non-human animals historically limited to song. However, song lacks discrete meaning, which is a crucial pre-requisite of linguistic syntax. Over the last two decades evidence of combinatoriality in the discrete, semantic calls of an array of taxa has accumulated, providing the opportunity to investigate potentially closer parallels to language. However, most examples remain limited to small repertoires of simple two-call sequences, preventing evidence of complex internal structuring like that seen in human sentences. The recent discovery that several species produce extensive repertoires of much longer call sequences, has provided the opportunity to investigate the full extent of syntactic structure in non-human call systems. Here we demonstrate that Western Australian magpies (Gymnorhina tibicen dorsalis) use multi-level structured ordering rules within their semantic call sequences and that these ordering rules are learned during development. Specifically, we find that calls within sequences up to 15 calls long depend on the two calls given prior and that independently produced segments ( phonemes), calls, and sequences recombine into longer structures, indicating hierarchical organisation. This represents the first evidence of multi-level non-adjacent organisation and learned syntactic structure in a semantic non-human system.

animal behavior and cognition↗

bioRxiv2026

Prey diversity revealed by environmental DNA elucidates ecological specialisation and social structure in bottlenose dolphins

Human disturbance drives rapid biodiversity loss, yet how prey diversity shapes individual niche differentiation and scales up to structure social organisation remains poorly understood, particularly in marine systems where prey are largely invisible to observation. Here we mapped prey community structure ( prey fields) using environmental DNA metabarcoding, integrating these maps with stable isotope data and >20 years of behavioural observations on bottlenose dolphins. We show that dolphins specialised on specific prey fields to varying degrees, and that none of 471 tracked individuals changed their predominant prey field -- even through climate-driven habitat reorganisation. Isotope profiles confirmed dietary differentiation scaling with specialisation strength. Across four independent sex-subpopulation networks, prey field overlap predicted social affinity in non-foraging contexts, revealing that prey community structure organises social ties beyond foraging. These results expose a socio-ecological link between prey diversity, trophic ecology, and social organisation, providing a transferable eDNA framework for predators with elusive prey.

ecology↗

bioRxiv2021

APOE4 genotype increases neuronal calcium signals and decreases pial arteriole responsivity and vasomotion in visual cortex of awake mice

Young mice possessing the e4 allele of the Apolipoprotein (APOE) gene (a risk factor for Alzheimers disease (AD)) have previously been shown to have dramatic decreases in vascular function, suggesting APOE4 may confer its risk via the vasculature. However, in human carriers, vascular and cognitive function decrease later in life. Mouse data may be confounded by an increased impact of anaesthesia and surgery in APOE4 animals, and has also focused on sensory cortices, ignoring medial lobe structures more sensitive to AD. To clarify how APOE4 expression alters neurovascular function, we studied the visual cortex and hippocampus of awake APOE3 and APOE4 targeted replacement mice, using 2-photon microscopy of neurons and blood vessels. We found milder vascular deficits than studies using anaesthetised preparations: functional hyperaemia was unaffected in APOE4 mice and neuronal or vascular function did not decrease with age. Instead, vascular responsiveness was lower at all ages, arteriole vasomotion was reduced and neuronal calcium signals during visual stimulation were increased. This suggests that, independently, APOE4 expression is not catastrophic but alters neurovascular physiology towards a state more sensitive to insults such as surgery or beta amyloid accumulation. Understanding how APOE4 expression interacts with these insults will be critical for understanding the emergence of AD in APOE4 carriers.

neuroscience↗