American Journal of Primatology

Why male primates invest in costly behaviours producing public goods remains debated, with two leading explanations, paternal care and reputation-based partner choice (RBPC). Using long-term data from four groups of wild vervet monkeys, we tested: (1) whether males show a bias in four protective "male services" (predator alarm calling, participation in between-group conflicts, leading river crossings and sentinelling); (2) which males contribute most; and (3) whether service provision predicts mating success during the mating season. We confirmed a male bias in all services. Consistent with the paternal care hypothesis, contributions were positively associated with past mating success, independently of rank, although potential fathers did not contribute more than non-fathers. Among non-fathers, service provision varied with rank, suggesting that newly immigrated males adjust their behaviour according to competitive state. Crucially, variation in alarm calling and between-group conflicts predicted future mating success, with between-group conflict emerging as the strongest and most consistent predictor of mating success across years and within mating seasons, whereas rank, tenure and social integration added little explanatory power. In contrast, sentinelling and leading river crossings did not reliably translate into mating benefits. Our findings indicate that male services are shaped by multiple selective pressures operating across different male career stages and that some forms of public goods provision function as signals of quality and cooperativeness to females. By directly linking cooperative investment to mating outcomes in a wild primate, this study provides rare empirical support for reputation-based partner choice beyond humans and highlights female choice as a potentially important force in the evolution of cooperation.

Approaching conspecifics is a fundamental component of social interactions. Such decisions are typically investigated through the study of social relationships (e.g., kinship, dominance, affiliation) and their impact. In the framework, the role of social affordances, i.e., interaction opportunities arising from the immediate social environment, remains poorly understood. We investigated how context-dependent factors shape approach decisions in wild crested macaques (Macaca nigra) in North Sulawesi, Indonesia. From September 2024 to May 2025, we collected data on 27 adults (20 females, 7 males) using focal observations and an approach-specific protocol recording neighbours identities and behaviours at the initiation of close-proximity approaches (<1 body length). We first compared data collected during approaches with focal data, then conducted within-approach analyses contrasting approached partners and bystanders. We further tested the effects of behavioural state, subgroup size and composition, including infant presence. Bayesian models revealed that affiliative, neutral, and grooming behaviours were more frequent in approach contexts than in general observations. Within approaches, individuals avoided congeners already engaged in grooming and approached individuals in neutral or affiliative states (e.g., lip-smacking, embracing). Macaques globally approached more isolated individuals or dyads. When multiple subgroups were present (i.e., multiple choices), the likelihood of being approached increased with subgroup size and was higher in subgroups containing infants. These findings indicate that macaques use behavioural cues and local social density as affordance signals, adjusting approach decisions to maximize interaction opportunities and navigate complex social environments.

One challenge of reintroduction programs is ensuring that captive individuals are prepared for life in the wild, including having the ability to forage on wild resources. Foraging proficiency can be especially challenging to foster in species with a wide dietary breadth or reliance on ephemerally available resources. A relatively unexplored obstacle to release readiness may be an animals hesitancy to approach or consume unfamiliar foods, i.e. their neophobia and dietary conservatism. In this study, we examined the responses of a conservation breeding population of the extinct-in-the-wild alal[a] (Corvus hawaiiensis), a dietary generalist, to novel and familiar native and non-native fruits. Birds were similarly willing to contact both novel and familiar fruits, suggesting little aversion to the presence and appearance of novel food items. However, birds showed a clear preference for contacting non-native fruits over native fruits, regardless of familiarity. Additionally, while birds were willing to contact novel items, they were less likely to consume novel native fruits, suggesting that dietary conservatism may limit incorporation of these resources in the wild. Finally, juvenile birds were less likely to approach the testing setup and contact items, suggesting that neophobia may constrain their exploration of novel environments and resources. We discuss the implications of alal[a] preferences for non-native foods and reluctance to consume novel native items for pre-release preparations and the goal of wild species recovery.

Zoological gardens strive to prioritize excellent animal care and adhere to the highest standards of animal welfare, ensuring that the conditions of animals` social and physical environment are as close as possible to those in the wild. This study investigates the effects of group split and relocation to the new enclosure on the behaviour of western lowland gorillas (Gorilla gorilla gorilla) (N = 7) living in Prague Zoo, Czech Republic. We conducted over 289 hours of behavioural observations focusing on daily activities, social interactions, and behaviours that serve as potential stress and welfare indicators. The group split led to establishment of two groups in two separate enclosures; the old enclosure consisted of a "bachelor group" (i.e. three males) and a new enclosure consisted of a mixed-sex group (i.e. three females and one juvenile male). The behavioural comparisons across different study periods were conducted using linear mixed models (LMMs). The changes led to an increase in time spent moving, feeding, being in social proximity, and higher rates of approaches among the gorillas, as well as to a decrease in rates of self-directed and "undesirable" behaviors. Our findings indicate that the gorillas effectively adapted to the changes, most likely by relying on social support, to navigate new conditions. This study contributes to our understanding of how socio-cognitively complex species cope with necessary alterations in captive animal care programs. Furthermore, these observations may inform strategies to enhance the welfare of zoo-housed animals and to improve their captive care.

Long-term studies of isolated animal populations have greatly improved the understanding of various evolutionary processes. However, potentially elevated inbreeding in those compared to wild populations is a common concern. Conventionally, inbreeding has been investigated using reconstructed pedigrees, but nowadays it can be done directly at the genomic level. Here, we utilize genomic data from an intensively studied isolated rhesus macaque (Macaca mulatta) population on the small island Cayo Santiago (Puerto Rico), which was founded in 1938 with wild animals from India. We quantified inbreeding levels by inferring runs of homozygosity (ROH), i.e., long identical haplotypes inherited from both parents. We identified ROH in 97 ~5x-coverage genomes from Cayo Santiago and, for comparison, in 79 rhesus macaque genomes from five wild populations from China. Notably, this conventionally considered low-coverage data proved sufficient to infer ROHs >4 centimorgans long after imputing the genomes using a reference panel. Our results revealed that the ROH-derived effective population size on Cayo Santiago, 420 individuals, falls within the ranges we inferred in wild populations. Moreover, a general scarcity of individuals with long ROH in both the Cayo and wild populations indicates very few cases of close-kin breeding, suggesting that mechanisms to avoid close-kin breeding operate in rhesus macaques, both in wild and isolated populations. Taken together, our results suggest that Cayo Santiago remains a representative study population.

Aims: Species' distributions are determined by the interplay between ecological niche and dispersal ability, constrained by biogeographical barriers. Bald-headed uakaris (Cacajao spp.) are highly specialized primates often associated with seasonally flooded forests. In this study, we used ecological niche models to assess changes in habitat suitability and geographic distribution of uakari species under future scenarios. Location: Western Amazonia. Methods: We integrated ecological niche models, current deforestation data, and dispersal ability to estimate habitat suitability under two Shared Socioeconomic Pathway (SSP) scenarios: intermediate (SSP2-4.5) and very high (SSP5-8.5) greenhouse gas (GHG) emissions. Results: Our models project shifts in suitable conditions for all species. Three of the five species are projected to experience substantial reductions ([&ge;]62%) in suitable habitat conditions within their current ranges by 2050 under both future scenarios. Across the western Amazonia, up to 219,189 km2 and 211,276 km2 of land are projected to be unsuitable within the uakari ranges under the intermediate and very high emissions scenarios, respectively. This is particularly relevant for C. calvus, C. rubicundus, and C. ucayalii. At the species level, the uakaris may lose between 343 km2 and 84,531 km2 of their ranges in the intermediate scenario and 858 km2 and 76,216 km2 in the very high scenario. Shifts in suitability due to climate change are expected to vary from 6 to 191 km in the intermediate scenario and from 5 to 168 km in the very high scenario. Furthermore, the uakaris may lose between 0.5% and 8% of their current ranges due to deforestation in all scenarios. Main conclusions: Our findings reveal a high sensitivity of the uakaris to climate change impacts. It is projected that all species may experience contractions in the suitable areas and spatial suitability within their ranges by 2050, underscoring climate change as a relevant threat to these taxa.

The timing of reproductive processes can influence how mating interactions shape reproductive strategies. We examined how female age correlates with receptivity and preference in the jumping spider Habronattus formosus, a system characterized by elaborate male courtship and strong female choice. To test how receptivity changes across the post-maturation period, we paired females of different ages with males and quantified male courtship displays and mating outcomes. Females were not receptive immediately after maturation and instead exhibited receptivity primarily 2-3 weeks after maturation. We further found that the full male courtship predicted mating success in older females, whereas only the second stage of the courtship predicted success in younger females. The delay in female receptivity is consistent with expectations for strong female choice systems, where females may have a greater opportunity to evaluate male courtship before mating. These results highlight the importance of age-dependent changes in female reproductive state and suggest that the timing of receptivity may shape how different components of male courtship influence mating success.

Effective conservation depends on demographic metrics that reliably reflect species status, particularly population abundance. For elusive species occurring at low densities, however, such metrics remain difficult to obtain. Spatial capture-recapture (SCR) models are the standardized approach for estimating density in marked populations, but their data requirements, especially the need for multiple spatial recaptures across individuals, often limit applicability in small or data-poor populations. This constraint has resulted in knowledge gaps for some of the most vulnerable species, undermining evidence-based conservation planning and management. Using camera-trap data and SCR-derived density estimates from data-rich populations, we evaluated alternative, less data-demanding metrics and tested the hypothesis: Space to Event (STE), Mean Local Abundance (MLA), and Relative Abundance Index (RAI) exhibit predictable relationships with SCR-derived density; if supported, these metrics can reliably estimate density in populations where SCR models cannot be implemented. We applied this framework to the European wildcat (Felis silvestris), an elusive small felid with highly fragmented populations across Europe, for which density estimates are largely lacking despite growing conservation concern. Across 21 study areas spanning most of the species' range, our results indicate that European wildcats generally occur at lower densities than previously reported. SCR-derived estimates (n=10) averaged 10.32 {+/-} 11.56 inds/100km2, while STE enabled density estimation in five additional data-poor areas (mean 5.52 {+/-} 5.33 inds/100km2). STE showed a strong linear relationship with SCR-derived density (R2=0.98), supporting its use as a viable alternative when SCR is infeasible, although it tended to underestimate compared to SCR, especially at higher densities. In contrast, MLA and RAI showed weaker and non-linear relationships with SCR-derived density (R2=0.65), indicating substantially lower explanatory power and suggesting their estimates are more strongly influenced by confounding processes. By explicitly calibrating alternative metrics across a wide density gradient throughout most of the species' distribution, this study provides a transferable methodological framework for estimating density in low-density wildlife populations and the first continent-wide, standardized density assessment of a carnivore species. From a management perspective, our findings identify populations that may be most vulnerable, particularly those with the lowest densities, and highlight the need to prioritize absolute abundance monitoring.

The tick Ixodes ricinus is the main vector of human and animal pathogens in Europe. Despite its importance in epidemiology and medicine, our understanding of physiological mechanisms controlling blood feeding, osmoregulation, or development are still limited. Here, we identify novel neuropeptide invertebrate parathyroid hormone-like peptide (iPTH) and its two receptors - PTHR1 and PTHR2 in I. ricinus. Functional aequorin-based assay confirmed specific activation of both receptors by iPTH. Using RT-qPCR we detected the PTHR1 transcript in the synganglion, while increased expression levels of PTHR2 were found in the salivary glands, hindgut and female gonads. RNA-mediated knockdown of iPTH receptors in nymphs resulted in delayed blood feeding, and a high incidence of defects in adult ecdysis. Consistent with observed phenotypes, iPTH is expressed in multiple neurons of the synganglion which project arborizing axons to the salivary glands, rectal sack and skeletal muscles. iPTH was colocalized with orcokinin-immunoreactivity (OK-IR) in all neurons that innervate these peripheral tissues. iPTH is further colocalized with tachykinin (TK) in Pd1DL1 neurons, suggesting coordinated action with other neuropeptides. Our findings indicate that iPTH signaling is required for normal feeding, development and successful ecdysis.

Racial equity remains a critical challenge in postsecondary science education, as Black students experience higher attrition rates and diminished well-being compared to their White peers. While active learning has been shown to reduce failure rates and narrow achievement gaps, the interpersonal affordances and constraints of peer discussions within these settings remain underexplored for Black students. Grounded in Critical Race Theory and utilizing the analytical lenses of racial microaggressions, microaffirmations, and Community Cultural Wealth, this study addresses this issue by investigating the racialized interpersonal experiences of Black students in active learning college science classrooms. Through semi-structured interviews, this study explores the nature of both exclusionary and affirming peer interactions and how students navigate these dynamics. Findings reveal that Black students frequently encounter racialized microaggressions--manifestations of macro-level anti-Blackness-- in the classroom which contribute to isolation and racial battle fatigue. Conversely, students describe instances of microaffirmations, predominantly through small counterspaces created by and for other students of color, which validate their intellectual contributions and foster a sense of belonging. Despite facing these tensions, participants advocate for active learning as a beneficial practice, provided that instructors implement explicit, equitable structures and facilitate culturally responsive classroom climates. These findings offer actionable implications for researchers and practitioners to design more inclusive active learning environments by explicitly addressing interpersonal dynamics, promoting cultural competence, and co-constructing humanizing science classroom climates.

A critical step in visual cortical maturation is refinement of receptive field (RF) size, producing higher acuity vision. This was previously studied using species with well-developed vision (e.g., carnivores, primates), in which visual experience was necessary for refinement but not maintenance of RFs in visual cortex. In contrast, in Syrian hamsters, a crepuscular species with low visual acuity, dark rearing had no effect on RF refinement in juveniles, but RFs re-enlarged in adulthood, resulting in reduced acuity. These inter-species differences raise the question of whether the need for visual experience is primarily related to the phylogenetic position of the species or to its ecological niche. Here we report that dark rearing had no effect on development or maintenance of RF properties of visual cortical neurons in nocturnal mice. Mice with lifelong visual deprivation refined and maintained their RF size over time. Furthermore, the development of stimulus direction tuning was unaffected by dark rearing. In contrast, surround suppression, orientation tuning and the sharpness of direction tuning were abnormal in dark reared mice. These and our previous results from hamsters show that species living in an ecological niche with minimal daylight exposure require little to no visual experience to develop and maintain refined RFs. This study is an important step in developing a better understanding of the role of visual experience in the development of visual processing circuitry and suggests that diurnal mammals may be a better model for human visual cortical development than mice.

Advances in metagenomic sequencing have transformed our understanding of host-associated microbiota, revealing critical roles in immune regulation, nutrient metabolism, and gastrointestinal (GI) homeostasis. However, the gut microbiome of large non-model species, particularly elephants, remains poorly characterized. Captivity introduces dietary, environmental, and management-related perturbations that may disrupt microbial balance and contribute to GI dysfunction. Here, we performed a longitudinal analysis of the fecal microbiome in five captive Asian elephants (Elephas maximus) at the Oregon Zoo exhibiting chronic fecal abnormalities, including mucus and inconsistent stool formation. Over 14 weeks, weekly fecal samples were collected and compared with samples from clinically normal elephants housed at three other zoological institutions. Using 16S rRNA gene sequencing, we identified marked differences in microbial community composition between affected and control elephants. Dysbiosis in Oregon Zoo elephants was characterized by enrichment of Akkermansia muciniphila and multiple members of the order Clostridiales, including taxa previously associated with gastrointestinal disorders. Administration of a commercially available probiotic formulation was associated with transient improvement in fecal characteristics and pronounced shifts in microbial composition, including a significant post-treatment reduction in overall microbial diversity and decreased abundance of several taxa linked to GI abnormalities. Notably, probiotic strains themselves were not detected, suggesting indirect or short-lived functional effects rather than durable colonization. Together, these findings provide one of the first longitudinal characterizations of gut microbiome dysbiosis in captive Asian elephants and identify candidate microbial contributors to chronic GI dysfunction in captivity, with implications for husbandry, dietary management, and microbiome-informed interventions in megafauna. Additionally, our study underscores the potential, although limited and likely indirect, benefit of probiotics when treating GI disorders in monograstric megavertebrates.

The AMY2B gene encodes pancreatic amylase, a critical enzyme for starch digestion. While previous studies have examined AMY2B copy number variation (CNV) in domestic and some wild animals, less is known about wild carnivores inhabiting regions with limited anthropogenic starch exposure. We analyzed blood samples for serum amylase activity and copy number variation in AMY2B gene from 8 wolves (Canis lupus), 11 brown bears (Ursus arctos), and 3 red foxes (Vulpes vulpes) from Bosnia and Herzegovina. AMY2B gene copy number was assessed using droplet digital PCR (ddPCR), and serum amylase activity and glucose levels were quantified. Although the number of fox samples was limited, foxes and wolves consistently harbored two copies of AMY2B, while brown bears exhibited higher CNV (3.67-8.40, mean 5.88). Serum amylase activity was highest in foxes, moderate in wolves, and variable but lower in bears. Despite differences in AMY2B copy number and serum amylase activity, circulating glucose concentrations did not differ significantly among species. Our findings suggest that variation in AMY2B copy number among wild carnivores may be associated with species-specific evolutionary histories and dietary adaptations, providing insight into genomic mechanisms underlying carbohydrate utilization in natural populations.

Social hierarchies are a nearly universal feature of animal groups, but whether dominance reflects a single generalized trait or a collection of context-specific competitive abilities remains unclear. Here, we assess social hierarchy in three strains of laboratory mice (BALB/c, C57BL/6, and Shank3B knockouts) of both sexes using three established paradigms: the tube test, the warm spot assay, and the void spot assay. Hierarchies emerged in all strains and both sexes across all three assays, but how animals established rank differed markedly by strain and sex. In the tube test, Shank3b-/- knockout females, but not males, lacked the winner effects seen in wild-type mice, indicating that the ability to build a winning streak depends on social recognition in a sex-specific manner. In the warm spot assay, females formed stronger hierarchies than males, particularly among mice on a C57BL/6 background, with high-ranking females actively displacing others from the warm platform. In the void spot assay, BALB/c mice of both sexes frequently displayed territory-marking behavior, a pattern that was less common in the other strains. Overall, individual rank rarely generalized across domains, despite high trial-to-trial repeatability for individuals within each assay. Together, these findings indicate that mice behave as dominance specialists rather than generalists, with strain- and sex-specific strategies for establishing rank in different competitive contexts, suggesting that distinct neural circuits likely underlie these separable components of competitive ability.

Remote island systems with small landmasses and reliable estimates of human occupancy are ideal model systems to disentangle the roles of global climatic changes and local human occupation on biota. Here, we used mitochondrial and nuclear genomic data from five endemic Fijian Lasioglossum (Homalictus) bee species to infer changes in effective population size (Ne). These ground-nesting bees are native, with non-specialised floral visitation habits, and distributed across the elevational gradient. All lowland species and populations showed strong signals of increasing Ne that correspond to the timing of human occupation of Fiji, but not Holocene climatic change. Highland populations, with greater isolation and present in regions less affected by anthropogenic impacts, did not show evidence of recent rapid increases in Ne. Population expansion rates across the elevational gradient differed between taxa, with significantly earlier and larger increases in predominantly lowland species than those with more restricted ranges in the highlands. This is consistent with the movement of people inland from coastal regions and into montane elevations of the island, and corresponding landscape changes that benefit the ecology of these bees. Specific life history traits of these bees, combined with substantive clearing of forest cover and floristic changes at lower elevations, has likely increased nesting opportunities and abundance of invasive floral resources. Our findings contrast with recent evidence that human occupation of Fiji has resulted in decreased ant biodiversity and raise the paradoxical possibility that human-mediated environmental changes may benefit some native montane tropical insect faunas.

Animal vocalisations can convey information about external events, but whether this goes beyond reflecting the emotional state elicited by these events is debated. To explore this, we studied the acoustic structure of common marmoset (Callithrix jacchus) phee (long-distance contact) and ek (alert/mobbing) calls produced in five treatments varying in the emotional valence and arousal they elicit (internal state), as well as food and social context (external events). We measured changes in arousal via nasal temperature and analysed both basic acoustic parameters and Mel-frequency cepstral coefficients (MFCCs) of the calls. Support Vector Machines combined with Linear Mixed effect models revealed that phee calls encode both external events and internal states, while eks reflected predominantly arousal. Notably, an acoustic signature related to food context was present in phees both when provided (positive valence) and teased with highly preferred food items (negative valence), and even when food was not physically present (food call playback treatment). This suggests marmoset long-distant phee calls encode external information beyond emotional arousal and valence, and independently of the presence of an immediately triggering stimulus.

Growing evidence of animals combining discrete, meaningful calls into sequences--a feature once thought unique to linguistic syntax--has presented the opportunity to investigate the evolutionary origins of syntactic communication. The arbitrary assignment of meaning to words marks an important step in human language evolution, and a necessary precursor to generating further meaning through sentences. Studying how other animals that produce call sequences learn the meaning of these signals could help shed light on how referentiality and semantic combinatoriality evolved. Given the presence of meaningful call sequences has only recently been revealed in several non-human animals, ontogenetic studies of the comprehension of these vocalisations are, to date, non-existent. Western Australian magpies (Gymnorhina tibicen dorsalis) combine discrete calls into a diverse array of call sequences. Recent evidence shows these sequences are socially learned, but the developmental stage at which fledglings respond correctly to them remains unstudied. We performed playbacks of a discrete alarm call and call sequence to fledglings over the course of their first 18 weeks out of the nest, identifying when they differentiate between the low-level disturbance associated with the discrete call and the high-grade aerial threat associated with the sequence. Fledglings showed immediate vigilance to both vocalisations but exhibited significantly greater vigilance and upward scanning following the sequence. Critically, fledglings showed this response to the sequence from the first week of testing, with no effect of age on the response to either vocalisation. These findings suggest that comprehension precedes production of sequences in magpies and that sequence meanings are either learned rapidly or have an innate basis. While further investigation is essential, this study offers the first empirical insight into the ontogenetic emergence of combinatorial comprehension in a non-human animal.

Wildlife hosts play important roles in the ecology and transmission of vector-borne parasites, yet information on host associations remains scarce in many biodiverse tropical regions. Within a One Health framework, characterizing parasite diversity in wildlife can improve understanding of ecosystem health and disease emergence. Road-killed animals provide a non-invasive opportunity to investigate host-parasite interactions while minimizing disturbance to natural habitats. We screened 127 liver and intestinal tissue samples obtained from 76 road-killed vertebrates collected near protected areas in two Ecuadorian biodiversity hotspots, the Tropical Andes and Choco-Darien, for trypanosomatids and other vector-borne microorganisms. Molecular analyses targeted the 18S rRNA and cytochrome b genes of trypanosomatids and included additional screening for Trypanosoma cruzi, Trypanosoma rangeli, Rickettsia spp., and piroplasmids. Twenty-nine samples were positive for kinetoplastids. We detected diverse trypanosomatids representing the genera Leishmania, Porcisia, Trypanosoma, Phytomonas, Blastocrithidia, and Obscuromonas, as well as free-living kinetoplastids of the order Neobodonida. The most frequently detected species was Leishmania amazonensis, identified in 17 samples from at least 13 species of birds, reptiles, and caecilians, predominantly in liver tissue, suggesting previously unrecognized host associations. We also identified a putatively novel species of Porcisia and three potentially undescribed avian trypanosomes belonging to the subgenus Ornithotrypanum. No evidence of T. cruzi, T. rangeli, Rickettsia spp., or piroplasmids was found. Our findings identify birds, reptiles, and caecilians as potential reservoir hosts of L. amazonensis. In addition, we substantially expanded current knowledge of kinetoplastid diversity in Ecuadorian wildlife. This study demonstrates the value of road-killed animals as a practical, non-invasive resource for wildlife pathogen surveillance and highlights the importance of integrating biodiversity research into One Health approaches to better understand parasite transmission dynamics in rapidly changing tropical ecosystems. Author summaryMany parasites that affect humans circulate naturally in wildlife, but identifying their animal hosts is often difficult in remote, biodiverse regions. We used road-killed animals as a non-invasive source of biological material to investigate parasites in wildlife from two biodiversity hotspots in Ecuador. By analyzing tissues from birds, reptiles, amphibians, and mammals, we found a remarkable diversity of kinetoplastid flagellates, a group that includes the agents of Chagas disease and leishmaniasis. Although we did not detect human-infective trypanosomes, we repeatedly identified Leishmania amazonensis (a species causing human disease) in birds, reptiles, and caecilians. These vertebrate groups have not previously been recognized as potential hosts of this parasite. We also discovered several undescribed trypanosomatid species, emphasizing how little is known about parasite diversity in tropical wildlife. Our results show that road-killed animals can provide valuable information on host-parasite interactions without disturbing living populations. Such surveillance contributes to One Health efforts by improving our understanding of how environmental change, wildlife, and human health are interconnected.

Behaviour innovation plays a pivotal role in a species adaptability to dynamic environments. Investigating innovative behaviour and its underlying mechanism is therefore crucial for elucidating the development of cognitive flexibility across animals. Animal personality--which shapes how individuals perceive and engage with their surroundings--could offer insights into individual variation in this process. This study used a three-step foraging puzzle to evaluate the innovation capacity in 28 rosy-faced lovebirds (Agapornis roseicollis), specifically examining their capacity to recombine individually innovated component behaviours into integrated, more sophisticated techniques. We found that nearly half of the individuals spontaneously innovated multiple component behaviours to solve novel puzzles. Crucially, when challenged with a more sophisticated task, they recombined these behaviours into functionally dependent sequences without prior social demonstration. We further identified sex, persistence, and asocial learning capacity as key predictors of innovative problem-solving performance, with females, persistent individuals, and superior asocial learners excelled at problem-solving. Our findings demonstrate that behavioural innovation is not a static event, but a dynamic process--modulated by physical, cognitive, and personality variables--in which behaviours are flexibly transferred and recombined into increasingly complex forms to enable rapid individual adaptation.

Voluntary physical activity is a highly motivated behavior with important implications for physical and mental health, yet the neural and endocrine mechanisms underlying motivation to exercise remain poorly understood. In contrast, motivation for sugar/palatable foods, drugs, and sex has been extensively characterized using operant paradigms. Here, we describe a novel progressive ratio operant task to measure motivation to run, independent of running ability. Using female Long Evans rats, which exhibit robust voluntary running behavior, we validated this paradigm by applying a manipulation well known to enhance the motivation to run: calorie restriction. Calorie-restricted animals exhibited increased operant responding to gain access to a running wheel, thus demonstrating heightened motivation for exercise. More specifically, calorie-restricted rats completed more ratios, reached a higher breakpoint in the progressive ratio task, ran more, and spent more time in the operant chamber. We did not observe any effects of calorie restriction on the estrous cycle or steroids (e.g. corticosterone, testosterone) in the blood or brain. Importantly, our task dissociates the motivational drive for physical activity from the ability to perform the physical activity itself, providing a new paradigm for studying the neural and endocrine mechanisms that regulate exercise motivation.