Western honeybees (Apis mellifera) are remarkable among insects for their ability to generate heat endogenously and maintain a stable hive microclimate. This process relies on the activity of the indirect flight muscles, but the direct relationship between thermogenesis and carbohydrate availability has not been systematically investigated. To investigate this relationship, we developed a controlled individual-level thermography assay that provides a standardized framework for studying honeybee thermogenesis at the individual level. Starved bees showed little or no thermogenesis, whereas sucrose-fed bees exhibited substantially increased thoracic temperatures and thermogenic activity, consistent with a threshold-like activation of thermogenesis. Additionally, thermogenic performance was significantly lower in bees fed a sucralose solution used as a putatively non-nutritive control than in bees that received the same volume of sucrose solution. Together, these findings support the hypothesis that thermogenesis depends on the availability of recently ingested carbohydrates.

The spotted lanternfly (Lycorma delicatula) is an invasive hemipteran spreading across the United States. Eradication campaigns, such as "See It, Squish It," rely on mechanical elimination. However, lanternflies often escape by executing hindlimb-driven leaps. Although escape rates remain unquantified, the physical nature of these eradication attempts likely results in individuals surviving with damaged/missing limbs. Lanternflies do not exhibit limb autotomy, and it remains unclear how well they tolerate injury. To evaluate the effects of limb loss on locomotor performance, we amputated a single fore-, mid-, or hindlimb in lanternfly nymphs and measured three ecologically relevant metrics: jumping and climbing velocity and pull-strength. We also tracked recovery over several days post-amputation for jumping and climbing trials. Jumping velocity and pull-strength were unaffected by limb removal. In contrast, climbing velocity declined significantly across all groups, with the greatest reductions observed following forelimb and hindlimb removal. This decrease in climbing velocity was associated with changes in both stride length and stride frequency. However, because climbing velocity also declined in the control group, it remains unclear whether limb amputation alone-or the intervention itself-was responsible for these effects. No evidence of performance recovery was observed over time. These findings demonstrate the fault-tolerant nature of the lanternfly locomotor system, likely supported by mechanical redundancy and decentralized neuromuscular control. The ability to maintain essential behaviors following limb loss may represent a complementary evolutionary strategy to autotomy-centered on resilience rather than pre-programed limb sacrifice. This performance robustness likely contributes to the lanternfly's invasive success.

Neophobia, the avoidance of novel stimuli, is a widespread and ecologically relevant behavior observed across vertebrates and invertebrates. It is important for survival and adaptability, affecting how individuals navigate and use their environments. Neophobia might decrease an organism's exploitation of novel resources, but it also provides protection from potential dangers. Neophobia has been extensively studied in ecological and biomedical contexts, yet these two fields differ in their experimental paradigms, focal species and research goals. This Review uses a systematic approach to clarify the relationships between various 'neophobias' and the neural mechanisms that mediate them in vertebrates. Most vertebrate work focuses on mammals and, to a lesser extent, birds. In mammals and birds, both the hippocampus and amygdala (in birds, the medial ventral arcopallium) play a role in novelty evaluation and decision-making processes. In mammals, especially in the context of taste, food and odor neophobia, the insular and gustatory cortices also play a critical role. Serotonin, dopamine, glutamate, noradrenaline (norepinephrine) and glucocorticoids all exhibit context-, species- and life stage-dependent effects on neophobia. Fewer studies have examined immune or genetic mechanisms, and non-mammalian vertebrates are understudied relative to laboratory-bred rodents. In this Review, we also highlight persistent inconsistencies in how neophobia is defined and measured, emphasizing the need to distinguish it from neophilia and anxiety-related behaviors. Overall, this Review reveals both common mechanistic themes and major taxonomic and methodological gaps. We conclude by outlining key directions for future research, including broader comparative approaches and greater integration of ecological context into mechanistic studies of neophobia.

Macroalgal-herbivore interactions are fundamental to the stability of coastal ecosystems and their vulnerability to climate-driven shifts will affect biodiversity and ecosystem functioning. However, the effects of climate change on species interactions may be context dependent and vary by seasonal oceanographic processes. We examined the effects of warming and acidification on an intertidal primary producer foundation species, Silvetia compressa, and its herbivore, Agathistoma eiseni, under differing upwelling regimes in early (low upwelling) and late spring (high upwelling). We measured metabolic rates including photosynthesis, respiration, and calcification after four weeks of exposure to a range of nine pH levels (7.2-8.0) at two temperature levels (16°C, 20°C). Rockweed responded more to acidification than to warming, but showed different seasonal responses, decreasing photosynthetic rates in early spring and increasing rates during late spring. Their snail consumer, however, responded most strongly to temperature, increasing both respiration and calcification rates under warm conditions in late spring. Our findings demonstrate that seasonal differences can modulate responses of macroalgae and herbivores to changing environmental conditions. Warming may increase top-down effects through increased snail metabolism, while acidification affects rockweed production to affect bottom-up forcing. By assessing physiological responses across different ecological regimes, our study advances understanding of how top-down and bottom-up processes interact in intertidal ecosystems under global change.

Frequency and intensity of animal vocalisations scale with body size resulting in smaller animals generally producing weaker and higher frequency sounds than larger animals. Echolocating bats are very small mammals that not only vocalise to communicate but also produce high frequency calls to perform echo guided foraging in a variety of environments. Thus, in addition to body size, vocal scaling in bats may likely be driven by foraging specialisations and environmental context. To test this hypothesis, we used a microphone array to record the echolocation behaviour of seven wild bat species (6-32 grams) orienting through a narrow tunnel during nightly cave emergence. Under these recording conditions, the bats faced the same sensory scene while solving the same natural behavioural task. As predicted from mammalian vocal scaling, the centroid frequency of calls decreased with body size for both constant frequency (CF) and frequency modulating (FM) bats. However, the frequency scaling slope of FM bats was less negative than predicted, suggesting convergence of call frequency across body size and foraging specialisations. Contrary to general scaling principles, call intensity and call intervals also converged across body size meaning that smaller bats called louder, and larger bats called more often than predicted by their size. This leads us to conclude that environmental context is a very important driver of bat echolocation behaviour and that this deviation from normal scaling principles must be considered when performing comparative sensory studies across bats of different sizes, foraging specialisations and sensory scenes.

Emergent technologies and integrative approaches have transformed our ability to understand organismal behavior, physiology, and evolutionary ecology. Baleen whales (Mysticeti) have evolved the largest body sizes by filter-feeding on dense aggregations of prey in diverse ocean ecosystems. Although the wide range of foraging modes and prey capture abilities among mysticetes has been well-documented, the functional morphology underlying these relationships remains poorly understood. Gray whale (Eschrichtius robustus) morphology and ecological niche contrast starkly from closely related lunge-feeding rorqual species (Balaenopteridae), with gray whales foraging closer to the coastline using longer skulls and flatter mandibles in comparison to most rorquals. We used video and motion-sensing biologging tags to quantify the kinematics of gray whales feeding on infaunal ghost shrimp (Neotrypnea californeinsis) in the shallow waters of the northern Puget Sound, Washington, USA. Tag-based kinematics were integrated with 3D models and morphological dimensions of the skull to calculate the skull area in contact with the seafloor during each feeding roll, resulting in an average minimum benthic contact area of 4.9 +/- 1.1 m2. Daily rates of feeding events (mean 292 +/- 153) were comparable to those of lunge-feeding rorqual species despite using an average of 47.3% (weighted by deployment length) of the available high-tide feeding window. We posit that the paddle-like mandibles of gray whales reflect an adaptation for infaunal prey capture that may facilitate benthic suction-filter feeding in shallow coastal habitats, potentially opening a unique coastal foraging niche among mysticetes.

An object on immediate collision course generates a rapidly expanding visual stimulus on the retina, which will typically trigger a fast reaction, such as an evasive behavior. In hoverflies, for example, visual looming stimuli may be generated if the insect is about to collide with a stationary object in the surround, by an approaching predator, or by conspecifics during territorial interactions. Supporting these behavioral responses is a diverse range of looming sensitive descending neurons that project information from the optic lobes and central brain to the motor control centers in the thoracic ganglia. We here show that the looming sensitive descending neurons are predominantly sensitive to looming stimuli located in the ventral visual field. To investigate if this is matched by behavior, we recorded how tethered hoverflies responded to looming stimuli presented dorsally or ventrally on a visual monitor, at four different speeds (l/|v| of 10 - 667 ms), covering a naturalistic range. We found that ventral stimuli, especially at intermediate speeds (l/|v|=50 or 200 ms), triggered much stronger behavioral responses than dorsally displayed stimuli. The behavioral data thus not only match the receptive fields of the neurons likely to support the behavior, but also highlight that behavioral output is not entirely reflexive but is strongly modulated by stimulus speed and elevation.

The interactions between thermal environments and morphology provide critical insights into how organisms adapt to ecological pressures. Leg and bill morphology in birds are commonly shaped by their thermal regime, with thermoregulatory use of the legs predicted by high temperature extremes and bill size limited by cold temperature extremes. This general pattern has a well-documented exception, however, where the bills of birds in saline habitats appear adapted to high rather than low temperatures. Here we present a test of the thermoregulatory use of the bill for high temperatures in three Ammospiza sparrow taxa, which face dual challenges of heat stress and freshwater limitation during the breeding season while representing a gradient of specialization to tidal saltmarshes. We quantified heat dissipation across ambient temperatures (10-35°C) using thermal imaging and examined inter- and intraspecific variation in bill-mediated heat loss and its relationship to bill size. We found that larger bills facilitated greater heat loss, with Seaside Sparrows, the most tidally adapted taxon, exhibiting the highest heat dissipation rates and thermal efficiency. Notably, Seaside Sparrows also displayed nonlinear heat dissipation patterns, with physiological control enabling rapid heat loss up to a thermal breakpoint (21.5°C) before plateauing. In contrast, Saltmarsh and Nelson's sparrows exhibited linear, passive heat dissipation patterns typical of other songbirds. These findings highlight the dual contributions of morphological and physiological adaptations to thermoregulation in a freshwater-limited ecosystem, report the most fine-tuned physiological control of bill vasculature yet in a passerine, and offer insights into the evolutionary pressures driving avian thermoregulatory strategies.

Bird feathers serve numerous essential functions, with water repellency being particularly critical, as many other feather functions depend on remaining dry. Despite its importance, significant gaps remain in our understanding of the mechanisms underlying feather water repellency. This property arises primarily from feather microstructure. Feather morphology varies widely among bird species. However, the functional consequences of this variation for feather wettability remain poorly understood. Advances in computer-aided 3D modeling enable us to investigate such structure-function relationships with unprecedented precision. In this study, we created 3D feather models from micro-computed tomography scans of a Seaside Sparrow feather and systematically altered its morphology, specifically barbule density, to observe how feathers interact with water droplets using computational fluid dynamics simulations. We quantified the spatio-temporal distribution of droplet behavior, measured spreading radii during interactions, and assessed final contact angles for feathers with varying barbule densities. We validated our simulation results with barbule-density estimates and static contact-angle measurements on contour feathers from four New World sparrow species, including the Seaside Sparrow, spanning a gradient in water exposure. Together, computational and experimental results demonstrate that higher barbule density reduces water repellency. Collectively, these findings highlight how feather microstructure directly governs feather wettability.

Streaked shearwaters (Calonectris leucomelas) return to their breeding colonies, which are established in elevated locations on islands, by increasing their flight altitude immediately before landing. We quantitatively analysed the characteristics of this energetically demanding ascending flight and examined how body mass influences flapping behaviour using high temporal resolution biologging data from eight individuals. We compared the proportion of time spent flapping, the period of dorsal-ventral axis acceleration cycle (the inverse of wingbeat frequency) and acceleration amplitude between ascending and sea-surface flight. The proportion of time spent flapping was considerably larger during ascending flight (94.6±6.5%) than during sea-surface flight (40.8±13.0%). The mean dorsal-ventral acceleration cycle was markedly shorter (0.233±0.008 s versus 0.247±0.008 s) and the mean amplitude was larger (8.85±0.82 m s-2 versus 7.20±0.49 m s-2) during ascending flight than during sea-surface flight. During ascent, birds increased wingbeat frequency, accompanied by greater body acceleration amplitude, indicating increased mechanical power output required for climbing flight. The increases in wingbeat frequency and amplitude were larger for heavier birds when transitioning from sea-surface to ascending flight, revealing that body mass strongly influenced flapping performance under high energy demand scenarios. Individual variation in body mass strongly affected the biomechanics and energy requirements of flight, providing insights into size-related trade-offs in the flight behaviour of island-breeding seabirds.

Bees use vibrations across behavioural contexts, including a specialised foraging routine in which they vibrate flowers to release pollen (floral vibrations). Floral vibrations often have complex spectral properties, combining fundamental frequencies and their harmonics, yet their functional consequences remain unknown. We experimentally replicated bee buzzes with identical fundamental frequency (300 Hz) but different harmonic content (0, 2, or 4 harmonics) to determine their effect on pollen release, a key functional outcome for both the bee and the flower. We normalised signals to the same average power by holding root mean squared (RMS) acceleration constant and applied three RMS levels to test for interactions between power and spectral composition. We applied vibrations to flowers and quantified both the input signal (at the shaker) and the vibration transmitted at a distal anther, and measured pollen release. Harmonic content did not explain pollen release at any RMS level. In contrast, RMS acceleration strongly predicted pollen removal. The RMS measured at the distal anther was only weakly correlated with the input RMS, suggesting that the flower strongly modifies the vibration signal. Both input RMS and distal anther RMS explained pollen release, irrespective of spectral composition. Our results suggest that pollen release is determined by vibration amplitude (RMS acceleration) rather than spectral composition and is jointly governed by the bee-generated input and the mechanical filtering properties of the flower.

Hibernation is a seasonally regulated process dramatically reducing metabolic rate and subsequently core body temperature (Tb). Many hibernators repeatedly cycle between torpor and arousal (T-A cycling) throughout the hibernation season. How these cycles are regulated is still unresolved. The sensing of metabolites accumulating / depleting during torpor may regulate T-A cycling. Here, we report the development of a microdialysis protocol to sample at a high temporal resolution from the 3rd ventricle (3V) of the hypothalamus, from an individual hibernating golden hamster (Mesocricetus auratus). Over multiple days and T-A cycles we saw no negative impact on hibernation physiology or dynamics during the microdialysis. We collected samples at 2-hour resolution over 2 successive T-A cycles and measured metabolites by targeted and untargeted metabolomics. Finally, we developed an analysis pipeline to identify accumulating or depleting metabolites during torpor, providing a proof of concept that CSF-microdialysis from the 3V of a hibernating golden hamster can be used in future studies to understand regulation of T-A cycling.

Seasonal changes in metabolic rate have been studied to varying degrees in terrestrial mammals, but relatively little is known about this phenomenon in odontocetes. Seasonal changes in thyroid hormone levels in bottlenose dolphins suggest potential seasonal effects on resting metabolic rate (RMR). To explore this potential, the RMR of nine adult and four adolescent bottlenose dolphins were measured monthly for 13 months using open-flow respirometry. Oxygen consumption was measured while dolphins were post-absorptive and during the morning to avoid diurnal hormone fluctuations. Blood samples were collected from six of the adult dolphins immediately following oxygen consumption measurements and assessed for levels of total and free T3 (fT3), reverse T3 (rT3), total and free T4 (tT4 and fT4, respectively), and cortisol. Resting metabolic rate varied seasonally in mature dolphins; RMRs were lower in the spring and higher in the summer and fall. Suppression of RMR in the spring was followed by a progressive increase in RMR through the summer and fall. The mean mass-specific RMR of adolescent dolphins (5.49 ml O2 min-1 kg-1) was higher than that of adult dolphins (4.38 O2/min/kg), and the RMR of adults did not vary between sexes. The RMR of adult dolphins was significantly related to serum concentrations of tT3 and fT3, while rT3, fT3, and tT3 were all significantly related to photoperiod. The entrainment of seasonal changes in dolphin RMR are probably driven by photoperiod, although the signaling mechanism mediated by melatonin is likely altered in this species because it lacks a defined pineal gland.

Animals time durations between arbitrary events to make predictions about their environment. This ability, known as interval timing, has been studied in the context of reward expectancy in the laboratory and foraging in the wild. However, timing is also used in other contexts, such as in animal communication. Communication signals have characteristic timing, which affects the sender's likelihood of attracting mates, fending off rivals and deterring eavesdroppers. The literature on timing in reward expectancy and communication is extensive, but there is little crossover between the two fields. Here, we review this literature while highlighting the neural mechanisms that may be shared between the two modes of timing. We focus our comparison on learned communication signals, such as birdsong, given that learning is also a crucial component of reward expectancy. However, we also argue that even the study of innate communication signals could shed light on the nature of the neural oscillators that animals use to keep track of time. We also highlight potential differences between interval and communication timing. We argue that timing precision might be particularly important in communication, as precision can be an honest indicator of quality. However, increased precision might occur at a cost to the range of intervals that can be produced in a signal. Thus, communication signals provide an opportunity to study the physiological constraints that limit the precision and range at which neurons can sustain rhythms to either produce rhythmic behavior or keep track of time.