Animal Behavior Research Articles

Morphometric parameters of blood lymphocytes in American mink (Neogale vison) selected for tameness and defensive aggression toward humans.

Although there is some evidence to suggest that there is a link between behavior and immune parameters in animals, this issue is still not well understood. In particular, there is a lack of understanding of how specific behaviors affect the size of immune cells. To address this issue, we investigated the relationship between behavior and the morphometric parameters of lymphocytes in American mink (Neogale vison) that have been selectively bred for aggression and tameness toward humans at the Institute of Cytology and Genetics in Novosibirsk, Russia, for 37 years. Minks with high ("-3") and medium ("-2") aggressiveness, moderate ("+ 3") and high tameness ("+ 6"), as well as those not affected by special behavior selection, were compared with each other. We found that aggressive and tame mink significantly differed in lymphocyte size, cytoplasm content and nucleus to cell ratio (NCR). The lymphocytes of tame mink were characterized by larger size, increased cytoplasm content and lower NCR compared to those of aggressive mink and unselected mink. Among the studied parameters, the largest differences were found in the size of lymphocytes between "+ 3" and unselected minks (p = 0.000018) and in the cytoplasm content between "+ 6" and unselected minks (p = 0.000039). Minks with similar behavior ("-3" and "-2", "+ 3" and "+ 6") showed no significant differences. Our data, combined with the strong correlation reported by other researchers between morphological characteristics of lymphocytes and cytokine levels indicates that selection for specific behaviors may lead to a rebalancing in the immune system.

Transplanted deep-layer cortical neuroblasts integrate into host neural circuits and alleviate motor defects in hypoxic-ischemic encephalopathy injured mice.

Hypoxic-ischemic encephalopathy (HIE) is a major cause of neonatal disability and mortality. Although intensive studies and therapeutic approaches, there are limited restorative treatments till now. Human embryonic stem cell (hESCs)-derived cortical neural progenitors have shown great potentials in ischemic stroke in adult brain. However, it is unclear whether they are feasible for cortical reconstruction in immature brain with hypoxic-ischemic encephalopathy. By using embryonic body (EB) neural differentiation method combined with DAPT pre-treatment and quantitative cell transplantation, human cortical neuroblasts were obtained and transplanted into the cortex of hypoxic-ischemic injured brain with different dosages 2 weeks after surgery. Then, immunostaining, whole-cell patch clamp recordings and behavioral testing were applied to explore the graft survival and proliferation, fate commitment of cortical neuroblasts in vitro, neural circuit reconstruction and the therapeutic effects of cortical neuroblasts in HIE brain. Transplantation of human cortical neural progenitor cells (hCNPs) in HIE-injured cortex exhibited long-term graft overgrowth. DAPT pre-treatment successfully synchronized hCNPs from different developmental stages (day 17, day 21, day 28) to deep layer cortical neuroblasts which survived well in HIE injured brain and greatly prevented graft overgrowth after transplantation. Importantly, the cortical neuroblasts primarily differentiated into deep-layer cortical neurons and extended long axons to their projection targets, such as the cortex, striatum, thalamus, and internal capsule in both ipsilateral and contralateral HIE-injured brain. The transplanted cortical neurons established synapses with host cortical neurons and exhibited spontaneous excitatory or inhibitory post-synaptic currents (sEPSCs or sIPSCs) five months post-transplantation. Rotarod and open field tests showed greatly improved animal behavior by intra-cortex transplantation of deep layer cortical neuroblasts in HIE injured brain. Transplanted hESCs derived cortical neuroblasts survive, project to endogenous targets, and integrate into host cortical neural circuits to rescue animal behavior in the HIE-injured brain without graft overgrowth, providing a novel and safe cell replacement strategy for the future treatment of HIE.

Analysis of behavioral flow resolves latent phenotypes.

The accurate detection and quantification of rodent behavior forms a cornerstone of basic biomedical research. Current data-driven approaches, which segment free exploratory behavior into clusters, suffer from low statistical power due to multiple testing, exhibit poor transferability across experiments and fail to exploit the rich behavioral profiles of individual animals. Here we introduce a pipeline to capture each animal's behavioral flow, yielding a single metric based on all observed transitions between clusters. By stabilizing these clusters through machine learning, we ensure data transferability, while dimensionality reduction techniques facilitate detailed analysis of individual animals. We provide a large dataset of 771 behavior recordings of freely moving mice-including stress exposures, pharmacological and brain circuit interventions-to identify hidden treatment effects, reveal subtle variations on the level of individual animals and detect brain processes underlying specific interventions. Our pipeline, compatible with popular clustering methods, substantially enhances statistical power and enables predictions of an animal's future behavior.

Exposure to constant artificial light alters honey bee sleep rhythms and disrupts sleep.

Artificial light at night (ALAN) changes animal behavior in multiple invertebrates and vertebrates and can result in decreased fitness. However, ALAN effects have not been studied in European honey bees (Apis mellifera), an important pollinator in which foragers show strong circadian rhythmicity. Colonies can be exposed to ALAN in swarm clusters, when bees cluster outside the nest on hot days and evenings, and, in limited cases, when they build nests in the open. We captured and maintained foragers in incubated cages and subjected them to constant light (LL), constant dark (DD), or 12h light:12h dark (LD) cycle, and observed them with infrared cameras. After 79h, there was a significant interaction of treatment and time because LL bees slept less. In detail, the bees maintained a regular sleep pattern for three days but LL bees showed a shift on the fourth day. LL bees had the largest sleep differences from LD controls, with trends of lengthened periods and increased phase misalignment from both LD and DD bees. LL bees also experienced significantly more disturbances from their nestmates and preferred to sleep in the lower portion of the cages, which had significantly lower light intensity. These findings suggest that ALAN can disrupt the sleep of honey bee foragers, which has implications for their behavior and overall colony health.

Cannula Implantation Reduces the Severity of the Beta Amyloid Effect on Peroxidized Lipids and Glutathione Levels in the Brain of BALB/c Mice

Sporadic Alzheimer’s disease (sAD) is the most common of neurodegenerative disorders. The lack of effective therapy indicates that the mechanisms of sAD development remain poorly understood. To investigate this pathology in animals, intracerebroventricular injection of β-amyloid peptide (Aβ) using a Hamilton syringe, either during stereotactic surgery or through a pre-implanted cannula, is used. In this study, we analyzed the effect of chronic cannula implantation on the severity of Aβ effects at the behavioral, histological, and biochemical levels. The results showed that the local damage to neural tissue caused by cannulation has no bearing on the effect of Aβ on animal behavior and the microglial parameters of the unilateral hippocampus two weeks after the Aβ administration. However, cannula implantation fundamentally modifies some biochemical markers of the oxidative stress that occurs in the brain tissue in response to Aβ administration. Thus, the presence of a cannula reduces the severity of the Aβ impact on the levels of peroxidized lipids and glutathione two- and 10-fold, respectively. It is important to note that the detected changes are chronic and systemic. This is known because the homogenate of the entire contralateral (in relation to the cannula implantation site) hemisphere was analyzed, and the analysis was performed two weeks after implantation. At the same time, cannulation does not affect the rate of reactive oxygen species production. The obtained data indicate that chronic implantation of a cannula into the brain of experimental animals fundamentally distorts some parameters of oxidative stress in the neural tissue, which are widely used to assess the severity of experimental Alzheimer’s-type diseases.

Hierarchical behavior control by a single class of interneurons

Animal behavior is organized into nested temporal patterns that span multiple timescales. This behavior hierarchy is believed to arise from a hierarchical neural architecture: Neurons near the top of the hierarchy are involved in planning, selecting, initiating, and maintaining motor programs, whereas those near the bottom of the hierarchy act in concert to produce fine spatiotemporal motor activity. In Caenorhabditis elegans, behavior on a long timescale emerges from ordered and flexible transitions between different behavioral states, such as forward, reversal, and turn. On a short timescale, different parts of the animal body coordinate fast rhythmic bending sequences to produce directional movements. Here, we show that Sublateral Anterior A (SAA), a class of interneurons that enable cross-communication between dorsal and ventral head motor neurons, play a dual role in shaping behavioral dynamics on different timescales. On a short timescale, SAA regulate and stabilize rhythmic bending activity during forward movements. On a long timescale, the same neurons suppress spontaneous reversals and facilitate reversal termination by inhibiting Ring Interneuron M (RIM), an integrating neuron that helps maintain a behavioral state. These results suggest that feedback from a lower-level cell assembly to a higher-level command center is essential for bridging behavioral dynamics at different levels.

NeuroMechFly v2: simulating embodied sensorimotor control in adult Drosophila.

Discovering principles underlying the control of animal behavior requires a tight dialogue between experiments and neuromechanical models. Such models have primarily been used to investigate motor control with less emphasis on how the brain and motor systems work together during hierarchical sensorimotor control. NeuroMechFly v2 expands Drosophila neuromechanical modeling by enabling vision, olfaction, ascending motor feedback and complex terrains that can be navigated using leg adhesion. We illustrate its capabilities by constructing biologically inspired controllers that use ascending feedback to perform path integration and head stabilization. After adding vision and olfaction, we train a controller using reinforcement learning to perform a multimodal navigation task. Finally, we illustrate more bio-realistic modeling involving complex odor plume navigation, and fly-fly following using a connectome-constrained visual network. NeuroMechFly can be used to accelerate the discovery of explanatory models of the nervous system and to develop machine learning-based controllers for autonomous artificial agents and robots.

Contributions of mirror-image hair cell orientation to mouse otolith organ and zebrafish neuromast function.

Otolith organs in the inner ear and neuromasts in the fish lateral-line harbor two populations of hair cells oriented to detect stimuli in opposing directions. The underlying mechanism is highly conserved: the transcription factor EMX2 is regionally expressed in just one hair cell population and acts through the receptor GPR156 to reverse cell orientation relative to the other population. In mouse and zebrafish, loss of Emx2 results in sensory organs that harbor only one hair cell orientation and are not innervated properly. In zebrafish, Emx2 also confers hair cells with reduced mechanosensory properties. Here, we leverage mouse and zebrafish models lacking GPR156 to determine how detecting stimuli of opposing directions serves vestibular function, and whether GPR156 has other roles besides orienting hair cells. We find that otolith organs in Gpr156 mouse mutants have normal zonal organization and normal type I-II hair cell distribution and mechano-electrical transduction properties. In contrast, gpr156 zebrafish mutants lack the smaller mechanically evoked signals that characterize Emx2-positive hair cells. Loss of GPR156 does not affect orientation-selectivity of afferents in mouse utricle or zebrafish neuromasts. Consistent with normal otolith organ anatomy and afferent selectivity, Gpr156 mutant mice do not show overt vestibular dysfunction. Instead, performance on two tests that engage otolith organs is significantly altered - swimming and off-vertical-axis rotation. We conclude that GPR156 relays hair cell orientation and transduction information downstream of EMX2, but not selectivity for direction-specific afferents. These results clarify how molecular mechanisms that confer bi-directionality to sensory organs contribute to function, from single hair cell physiology to animal behavior.

Contributions of mirror-image hair cell orientation to mouse otolith organ and zebrafish neuromast function

Otolith organs in the inner ear and neuromasts in the fish lateral-line harbor two populations of hair cells oriented to detect stimuli in opposing directions. The underlying mechanism is highly conserved: the transcription factor EMX2 is regionally expressed in just one hair cell population and acts through the receptor GPR156 to reverse cell orientation relative to the other population. In mouse and zebrafish, loss of Emx2 results in sensory organs that harbor only one hair cell orientation and are not innervated properly. In zebrafish, Emx2 also confers hair cells with reduced mechanosensory properties. Here, we leverage mouse and zebrafish models lacking GPR156 to determine how detecting stimuli of opposing directions serves vestibular function, and whether GPR156 has other roles besides orienting hair cells. We find that otolith organs in Gpr156 mouse mutants have normal zonal organization and normal type I-II hair cell distribution and mechano-electrical transduction properties. In contrast, gpr156 zebrafish mutants lack the smaller mechanically evoked signals that characterize Emx2-positive hair cells. Loss of GPR156 does not affect orientation-selectivity of afferents in mouse utricle or zebrafish neuromasts. Consistent with normal otolith organ anatomy and afferent selectivity, Gpr156 mutant mice do not show overt vestibular dysfunction. Instead, performance on two tests that engage otolith organs is significantly altered – swimming and off-vertical-axis rotation. We conclude that GPR156 relays hair cell orientation and transduction information downstream of EMX2, but not selectivity for direction-specific afferents. These results clarify how molecular mechanisms that confer bi-directionality to sensory organs contribute to function, from single hair cell physiology to animal behavior.

ONIX: a unified open-source platform for multimodal neural recording and perturbation during naturalistic behavior.

Behavioral neuroscience faces two conflicting demands: long-duration recordings from large neural populations and unimpeded animal behavior. To meet this challenge we developed ONIX, an open-source data acquisition system with high data throughput (2 GB s-1) and low closed-loop latencies (<1 ms) that uses a 0.3-mm thin tether to minimize behavioral impact. Head position and rotation are tracked in three dimensions and used to drive active commutation without torque measurements. ONIX can acquire data from combinations of passive electrodes, Neuropixels probes, head-mounted microscopes, cameras, three-dimensional trackers and other data sources. We performed uninterrupted, long (~7 h) neural recordings in mice as they traversed complex three-dimensional terrain, and multiday sleep-tracking recordings (~55 h). ONIX enabled exploration with similar mobility as nonimplanted animals, in contrast to conventional tethered systems, which have restricted movement. By combining long recordings with full mobility, our technology will enable progress on questions that require high-quality neural recordings during ethologically grounded behaviors.

Short-Term Changes in Food Spatial Distribution by Zoo Husbandry Practices Increase Agonism and Affect Feeding Behavior in Chilean Flamingos (Phoenicopterus chilensis): A Case Study

ABSTRACT Short-term modifications to animals’ enclosures, stemming from zoo husbandry practices, can significantly impact animal behavior and, consequently, their welfare. In this case study, we examined a captive-bred population of 23 adult Chilean flamingos (Phoenicopterus chilensis) during a non-breeding season to evaluate whether short-term alterations in the spatial distribution of feeders would affect the birds’ feeding and agonistic behaviors. Initially, we developed an ethogram to establish baseline behavioral data. Subsequently, we assessed individual (latency to approach the feeders) and group (feeding and agonism) responses to feeder changes using an ABA-type experimental design (A1 and A2 feeders at the original location; B feeder location changed). Latency to approach feeders was also correlated with the birds’ sex and body weight. The results revealed that during and immediately after the alterations, agonistic behaviors at the most frequently used feeding site by the flamingos increased, while the use of alternative food sources decreased significantly. Latency was not influenced by the birds’ sex or body weight. These findings emphasize the importance of closely monitoring even seemingly minor changes in food spatial distribution to prevent negative impacts on the behavior, and presumably, the welfare of flamingos.

Structure-guided design and evaluation of CRM197-scaffolded vaccine targeting GnRH for animal immunocastration

Immunocastration is a humane alternative to surgical castration for controlling population and estrous behaviors in animals. Gonadotropin-releasing hormone (GnRH), the pivotal initiating hormone of the hormonal cascade in mammals, is the optimal target for immunocastration vaccine development. Cognate antigen-mediated cross-linking of B cell receptors (BCRs) is a strong activation signal for B cells and is facilitated by repetitive surface organizations of antigens. In this study, we describe the structure-guided design of highly immunogenic chimeric proteins with variant numbers of GnRH peptide insertion by epitope grafting. Linear B-cell epitopes of cross-reacting material 197 (CRM197) were replaced with multiple copies of GnRH peptide, and the inserts were displayed on the surface of the designs while maintaining the overall folding of CRM197. Among the seven designs, TCG13, which carries 13 copies of GnRH peptide, was the most immunogenic, and its immunocastration efficacy was evaluated in male mice. Vaccination with the BFA03-adjuvanted TCG13 induced potent humoral immunity and reduced the serum testosterone concentration in mice. It could significantly decrease sperm quality and severely impair gonadal function and fertility. These results demonstrate that CRM197 holds great value as a scaffold for epitope presentation in peptide-based vaccine development and supports TCG13 as a promising vaccine candidate for animal immunocastration.Key points• Provide a feasible way to design chimeric immunogen targeting GnRH by epitope grafting.• CRM197 can accommodate the insertion of multiple copies of heterologous epitope peptides.• Administration with the most immunogenic design led to effective immunocastration in male mice.

Compositional pretraining improves computational efficiency and matches animal behavior on complex tasks.

1Recurrent neural networks (RNN) are ubiquitously used in neuroscience to capture both neural dynamics and behaviors of living systems. However, when it comes to complex cognitive tasks, training RNNs with traditional methods can prove difficult and fall short of capturing crucial aspects of animal behavior. Here we propose a principled approach for identifying and incorporating compositional tasks as part of RNN training. Taking as target a temporal wagering task previously studied in rats, we design a pretraining curriculum of simpler cognitive tasks that reflect relevant sub-computations. We show that this pretraining substantially improves learning efficacy and is critical for RNNs to adopt similar strategies as rats, including long-timescale inference of latent states, which conventional pretraining approaches fail to capture. Mechanistically, our pretraining supports the development of slow dynamical systems features needed for implementing both inference and value-based decision making. Overall, our approach is an important step for endowing RNNs with relevant inductive biases, which is important when modeling complex behaviors that rely on multiple cognitive computations.

TRANCE STEREOTYPIES IN HUMAN AND PRIMATE PANTOMIMICRY

The authors reviewed and analysed Russian and foreign experimental studies on pantomimic stereotypes. Initially, stereotypical behaviuor was negatively evaluated. Modern research considers adaptive functions and possibilities of self-stimulation as a way to harmonise emotional and mental state. A comparative analysis of circular, pendulum and diagonal movements in children and Old World monkeys was conducted using an ethological approach to the study of behavioural patterns. Human observations were conducted in the psychoneurological department of Silischeva Astrakhan Regional Children’s Clinical Hospital, 40 preschool children with mental dysontogenesis participated. Five laboratory macaques and a family of hamadryas baboons kept in an aviary with homologous kinesics were observed in Sukhumi nursery. According to the authors’ team, walking (running) in a circle and diagonally, swinging the body “right-to-leftˮ in the pantomimic production of children and monkeys are associated with self-stimulation of an altered state of consciousness. Trance stereotypes divert attention from external stressors and stimuli and harmonise mental homeostasis. The study may be of interest to anthropologists, primatologists, specialists in the study of the psyche and pathological behaviour of animals and Homo sapiens.

Neural Networks for Audio Classification: Multi-scale CNN-LSTM Approach to Animal Sound Recognition

Abstract. This research explores the application of neural networks, specifically CNN-LSTM models, for classifying sound signals from dogs, frogs, and cats, selected from the ESC-50 dataset. The sound data was preprocessed using Mel-frequency cepstral coefficients (MFCCs) and augmented through time stretching, pitch shifting, and noise addition to enhance model generalization in varied acoustic environments. We compared two deep learning models: a traditional CNN-LSTM and an improved version with multi-scale feature extraction, allowing for capturing both short-term and long-term sound patterns. Our findings show that the multi-scale CNN-LSTM architecture outperforms the traditional CNN-LSTM, achieving a test accuracy of 86.11% compared to 80.56%. These results highlight the effectiveness of multi-scale feature extraction for handling complex audio signals. This research offers valuable insights into bioacoustics and has broader applications in areas such as environmental sound monitoring, wildlife preservation, and animal behavior analysis.

Artificial Light at Night Advances the Onset of Vocal Activity in Both Male and Female Great Tits During the Breeding Season, While Noise Pollution Has Less Impact and Only in Females

Artificial light at night (ALAN) and noise pollution are two important stressors associated with urbanisation that can have a profound impact on animal behaviour and physiology, potentially disrupting biological rhythms. Although the influence of ALAN and noise pollution on daily activity patterns of songbirds has been clearly demonstrated, studies often focus on males, and the few that examined females have not included the potential influence of males on female activity patterns. Using free-living pairs of great tits (Parus major) as a model, we examined for the first time the effects of ALAN and noise pollution and their interaction on the onset of (vocal) activity in both members of a pair. We focused on the egg-laying phase, when both sexes are most vocally active. The onset of male dawn song, female emergence time from the nest box and the onset of female calling in the nest box were measured and used as a proxy for the chronotype. The repeatabilities for all chronotype proxies were high, with higher repeatabilities for males. Consistent with previous studies, ALAN advanced the onset of male dawn song, while it did not elicit a strong response in female emergence time. Additionally, our results suggest an indirect effect of ALAN on the onset of female vocal activity via acoustic interaction with the male. Noise pollution advanced the emergence time in females, while an interaction between ALAN and noise pollution was found for the onset of female calling. In agreement with previous studies, several covariables were shown to have an influence on the activity onset. Taking several proxies for chronotype into account, this study has provided robust evidence of effects of ALAN on male and female cavity-nesting songbirds during the egg-laying period.

Single Intranasal Administration of Ucn3 Affects the Development of PTSD Symptoms in an Animal Model

Post-traumatic stress disorder (PTSD) is a multifactorial psychological disorder that affects different neurotransmitter systems, including the central CRH system. CRH acts via the CRHR1 and CRHR2 receptors, which exert opposite effects, i.e., anxiogenic or anxiolytic. The aim of this work was to investigate how intranasal administration of the CRHR2-specific agonist urocortin 2 (Ucn2) or urocortin 3 (Ucn3) affects manifestations of PTSD in a single prolonged stress (SPS) animal model of PTSD. Elevated plus maze (EPM) and open field (OF) tests were used to assess anxiety-like behavior. Changes in the gene expressions of CRH, CRHR1, CRHR2, glucocorticoid receptor (GR), and FKBP5 were measured in brain regions (BNST, amygdala, and PVN) responsible for modulating the stress response. The SPS animals spent less time in the OF central zone and were less mobile than the controls; however, the Ucn3 treatment reversed this effect. SPS decreased the GR and FKPB5 mRNA levels in the PVN. Ucn3 suppressed the effect of SPS on FKBP5 mRNA expression in the PVN and increased FKBP5 mRNA in the BNST and PVN compared to the stressed animals. We demonstrate that Ucn3 has the potential to ameliorate anxiety-like behavior in SPS animals and also to affect the neuroendocrine system in the BNST and PVN. In addition, we confirm the important role of CRHR2 signaling in mediating the stress response.

Conflict during learning reconfigures the neural representation of positive valence and approach behavior.

Punishing and rewarding experiences can change the valence of sensory stimuli and guide animal behavior in opposite directions, resulting in avoidance or approach. Often, however, a stimulus is encountered with both positive and negative experiences. How is such conflicting information represented in the brain and resolved into a behavioral decision? We address this question by dissecting a circuit for sexual conditioning in C.elegans. In this learning paradigm, an odor is conditioned with both a punishment (starvation) and a reward (mates), resulting in odor approach. We find that negative and positive experiences are both encoded by the neuropeptide pigment dispersing factor 1 (PDF-1) being released from, and acting on, different neurons. Each experience creates a distinct memory in the circuit for odor processing. This results in the sensorimotor representation of the odor being different in naive and sexually conditioned animals, despite both displaying approach. Our results reveal that the positive valence of a stimulus is not represented in the activity of any single neuron class but flexibly represented within the circuit according to the experiences and predictions associated with the stimulus.

Implementations of sign- and goal-tracking behavior in humans: A scoping review.

Animal research has identified two major phenotypes in the tendency to attribute incentive salience to a reward-associated cue. Individuals called "sign-trackers" (STs) preferentially approach the cue, assigning both predictive and incentive values to it. In contrast, individuals called "goal-trackers" (GTs) preferentially approach the location of the upcoming reward, assigning only a predictive value to the cue. The ST/GT model has been shown to be relevant to understanding addiction vulnerability and other pathological behaviors in animals. Therefore, recent studies tried to implement this animal model in the human population. This scoping review aimed to identify and map evidence of human sign- and goal-tracking. Studies that explicitly measured human sign- and goal-tracking or related phenomena (e.g., attentional bias induced by reward-related cues), using paradigms in line with the animal model, were eligible for this review. We searched for published, unpublished, and gray literature (PhD theses, posters, conference papers) through the following databases: MEDLINE, Scopus, PsycINFO, Embase, OSF, and Google Scholar. The JBI scoping review methodology was adopted. Screening and extraction were carried out by three reviewers, in pairs. A total of 48 studies were identified. These studies used various experimental paradigms and used the term "sign-tracking" inconsistently, sometimes implicitly or not at all. We conclude that the literature on human sign-tracking is very heterogeneous on many levels. Overall, evidence supports the existence of sign- and goal-tracking behaviors in humans, although further validated research is crucially needed.

Should Zoo Food Be Chopped for Ruffed Lemurs? It's Not so Black and White.

Whole food diets in zoos have the potential to reduce microbial contamination and keeper preparation time, whilst also reducing food nutrient breakdown. Given these benefits, it is important to determine whether there is any value in chopping up food. Lemurs (Family Lemuridae) are common in zoos, with over 7500 individuals housed globally. Given their regular occurrence in collections, plus the high incidence of frugivory, lemurs are an excellent taxon to investigate food presentation effects on behavior. A study was undertaken at Beale Wildlife Park on a group of four black-and-white ruffed lemurs (Varecia variegata) to investigate food presentation and preference. Animal behavior was recorded using instantaneous focal sampling at 60 s intervals to record state behaviors and continuous focal sampling to record event behaviors in 1-h sessions. Food preference was done by recording the first three food items consumed by individual lemurs. Overall, food manipulation was significantly increased during whole food presentation allowing the lemurs to display species-specific behaviors. Feeding and foraging were highest during very chopped food condition and inactivity was lowest in very chopped food presentation. When looking at aggressive interactions, there was an increase in stealing and locomotion with food during whole food presentation, whereas biting and startle were lower. Proving high-value food items chopped and low-value food items whole could reduce aggression while reduce aggression seen over high-value food items. For food preference, sweet potato was consistently in the top three food items for all lemurs, with beetroot being the second most-picked food item. This suggests that these individuals have a strong preference for food items high in carbohydrates. Keeper preparation time was significantly reduced during whole food preparation. Further research assessing a wider range of zoo-housed species would be beneficial to assess the effects of food presentation on behavior.