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Detection of a present predator is critical for prey survival, but prey cannot remain constantly vigilant without suffering fitness costs. To reduce the costs of vigilance, prey species use different cues to determine if another animal is a predator. We wished to determine whether or not Pelegrina helenae would respond to digital images of Phidippus audax as predators and whether the size of an image played a role in predator recognition response. P. helenae were placed in a plastic enclosure facing an iPhone X and shown an image of either P. audax or a ladybug and trials were recorded using a GoPro Hero 7. A second experiment was then performed where spiders were shown the same stimuli, but all ladybug stimuli had been increased to match the size of the P. audax stimuli. The presence of a Phidippus audax stimulus on screen significantly increased the vigilance duration of Pelegrina helenae which indicates that there is some specific visual predator cue that P. helenae is using to identify P. audax as a predator. Size on an image was not significant in the global model, but in the artificial size model, the vigilance duration between P. audax and the ladybug stimulus was not significantly different, indicating that size does play some role in predation risk, but not a large enough role to override specific predator cues.

A thesis submitted in total fulfilment of the requirements for the degree of Doctor of Philosophy to the School of Agriculture, Biomedicine and Environment, La Trobe University, Victoria, Australia.

Trade-offs shape animal behaviour. For decades, the study of trade-offs has provided insight into how animals make decisions, but they have rarely been explored in relation to sleep. A new study reveals a role for sleep in saving energy in garden warblers on a stopover during a northward migration, but with ecological costs.

Sleep is a highly conserved state across the animal kingdom. However, sleep duration, behavior and associated neural activity show great diversity across taxonomic groups, and sometimes even within the same species. Understanding sleep functions depends on understanding when sleep emerged, which of its characteristics have persisted throughout evolution, and what accounts for the similarities and differences in sleep behavior and neurophysiology across different species. Here, we provide an overview of the latest findings in comparative sleep neurophysiology and highlight remarkable examples of sleep flexibility. We discuss the implications that these findings have on the proposed functions of sleep.

Submitted in total fulfilment of the requirements for the degree of Doctor of Philosophy to the Department of Microbiology, Anatomy, Physiology and Pharmacology, School of Agriculture, Biomedicine and Environment, La Trobe University, Victoria.

Cilia are cell appendages that sense our environment and are critical in cell-to-cell communication. Dysfunction of cilia can result in several disease states including obesity. While cilia in the brain are known to be important for feeding behavior, it is unclear how they regulate energy homeostasis. Classically, cilia coordinate signaling through surface receptors called G-protein coupled receptors (GPCRs). For example, cilia mediated GPCR signaling is critical for both our senses of vision and smell. How cilia regulate the signaling of GPCRs in other areas of the body including the brain is only now emerging. To answer cell biology questions around cilia mediated GPCR signaling in neurons, we developed a system for primary neuronal cultures. We discovered that the cilia mediated hedgehog pathway influences the ability of neurons to respond to GPCR ligands. For the first time, this result highlights the role of the hedgehog pathway in neurons. We continue to explore how cilia integrate the hedgehog pathway and GPCR signaling in the central nervous system, and the potential connections to energy homeostasis. We discovered that hedgehog pathway activity in feeding centers of the brain changes based upon feeding conditions like fasting. We also learned that activating the hedgehog pathway in these brain regions is sufficient to cause obesity in mice. These novel results highlight an unrecognized role for the hedgehog pathway in the regulation of feeding behavior. Overall, this work provides a better understanding of ciliopathy associated obesity and may reveal more common mechanisms of obesity in the general population. In addition, this work implicates the hedgehog pathway in regulating behaviors and new modes of cell-cell communication within the central nervous system.

My thesis revolves around neuronal circuit dynamics in health and disease. The first part of the thesis characterized cross-regional synchrony within the visual cortical network following visual perceptual experience in healthy mice. This work for the first time described inter-areal 4-8 Hz superficial layer LFP synchrony across mouse visual cortical regions persisting beyond visual stimulation time window, and revealed that the synchrony was expressed specifically between V1 and the higher-order visual area (HVA) with functional preference matching the entrained spatial frequency (SF) and temporal frequency (TF) content, in mice. The discovery of visual familiarity induced inter-areal 4-8 Hz synchrony extends the previous discovery of the 4-8 Hz oscillation in V1 after visual experience from our lab (Kissinger et al., 2018; Kissinger et al., 2020; Gao et al., 2021), and provided the first pivotal evidence supporting the role of 4-8 Hz oscillation in mediating cross-regional communication. Such 4-8 Hz visual cortical network synchrony has been mostly reported in primate studies in contexts of visual attention and working memory (Liebe et al., 2012; Spyropoulos et al., 2018), while our study extended the visual cortical network synchrony research scope to mouse models and in a new context of visual familiarity. The work is a key step for starting cortical network studies in mice, and for starting predictive coding theory study in the context of oscillations in mouse cortical network in the future. Additionally, unit spiking was more strongly modulated by 4-8 Hz oscillations in V1 and HVAs after visual experience. The visually-locked responsive units in V1 and HVAs exihibted either increased or decreased inter-areal spiking synchrony, while most post-stimulus responsive units in V1 and HVA exhibited higher spiking synchrony. The other parts of my dissertation looked at V1 activity in disease and following a novel CNS therapy. One project looked at recovery of visually evoked response in mouse V1 after ischemia through NeuroD1 mediated astrocyte-to-neuron conversion, where we characterized the formation of cortical laminated structure from the converted neurons, longitudinal recovery of visually evoked responses of unit populations in V1, and units’ selective responses to orientations. Another project looked at altered visual cortical activity in an Auxilin knockout mouse model, which demonstrated overall reduced visually evoked responses, less selective responses to orientations, impaired visual adaptive responses and mismatch responses, as well as slower visual experience induced oscillations. These projects utilized the high-density silicon probe recording technique to 1) characterize visual cortical function recovery following a therapy, which provided evidence for its high efficacy for recovering physiological functions, and to 2) phenotype visual cortical functional impairments in a mouse disease model, which provided more basic understanding in visual cortical physiology of Auxilin related disease. In sum, my dissertation work took advantage of the high-density silicon probe recording technique to probe neuronal circuits in health and disease. The discovery of visual experience induced inter-areal 4-8 Hz synchrony paves the way for studying 4-8 Hz activity in relation to stream-dependent visual processing and predictive coding in health and disease.

Home cage aggression in male laboratory mice continues to challenge preclinical researchers. It reduces animal welfare and can alter research parameters, potentially reducing the validity and reliability of study data. While simply reducing aggression would be beneficial, promoting socio-positive, affiliative behaviors would greatly improve mouse welfare as mice are a social species. Mice also use olfaction to communicate, so this sensory modality could be used as a tool to improve social interactions in the home cage. A scoping review of the literature on how mammalian odor signals impact same sex social behavior found that studies are dominated by rodent subjects, treatments from urine, and aggression measures (Chapter 1). As a whole, urine treatments had a variable effect on aggression. This review highlights that treatments from non-urinary sources are not often tested, and affiliative behavior is rarely measured. One murine odor source worth exploring is found in used nesting material. Mice build complex nests for insulation and it has been speculated that the nest holds odor signals that appease home cage aggression, particularly aggression triggered by cage cleaning. It has been suggested that the nest contains secretions from plantar sweat glands, but the chemical content of neither nesting material nor plantar sweat have been examined. The main goals of this dissertation are to identify the odors stored in used nesting material, determine the sources of those odors, and test them for a behavioral role. Samples of used nesting material were collected from cages of group housed male mice. Further, plantar sweat, saliva, and urine were collected from the dominant and subordinate mouse in each cage as plausible odor sources. All samples were analyzed for protein and volatile organic compound content. Home cage aggression and affiliative behavior were also recorded to compare to odor profiles. Protein profiles showed that used nesting material contains a variety of proteins that primarily originate from plantar sweat, saliva, and urine sources (Chapter 2). A large proportion of these proteins contain messages about individual identity and bind volatile compounds that further contribute to identity cues. This suggests that the nest aids in maintaining a familiar odor environment. Analysis of volatile content showed that small compounds in the nest are also traced back to plantar sweat, saliva, and urine sources (Chapter 3). Few of the compounds have a known behavior role. However, one compound detected in nest, sweat, and saliva samples had a negative correlation with home cage aggression and three compounds (two from sweat and one from urine) had a positive correlation with affiliative behaviors, making them potential candidates for controlled studies on social behavior. Before testing the four candidate compounds, a challenge from the correlation study needed to be addressed. Body fluid samples were collected from individual mice based on social status, as this factor impacts production of known murine pheromones. Further, aggression is typically directed from a dominant to a subordinate mouse for territorial reasons. An aggression appeasement signal is likely to be produced by a subordinate to mitigate the dominant mouse’s perceived threat. Data from the correlation study showed no odor profile differences based on social status, and the pheromones that are known to vary with social status did not differ between dominant and subordinate mice. Therefore, Chapter 4 assesses the convergent validity of several dominance measures. Over one week, home cage interactions were observed in group housed male mice. For every aggression occurrence, the aggressor and target mouse was recorded to calculate individual dominance rankings in each cage. Then, individual mice were evaluated for the following measures known to correlate with dominance: levels of urinary darcin (a murine pheromone); scores from three rounds of the tube test; and ratio of preputial gland weight to body length. Postmortem wounding was also compared. Results showed that urinary darcin and preputial gland ratio have strong convergent validity with dominance ranking based on home cage aggression. Finally, the four candidate compounds (identified in Chapter 3) were developed into treatment solutions to assess their effect on home cage social behavior (Chapter 5). Cages of group housed male mice were randomly assigned one of five treatments (four compounds + control) and home cage aggression and affiliative behavior were recorded for one week. Postmortem wounding was recorded as a secondary aggression measure and social stress was measured through fecal corticosterone metabolites from each cage’s dominant and subordinate mouse (rank based on preputial gland ratio). Treatment did not predict changes in most measures. This may be due to limitations in application or from the original correlation study, which are further discussed. Although the final study showed null results, future research is still warranted to fine tune application methods and gain a better understanding of how odor signals impact interactions other than aggression. The relationship between olfaction and affiliative behaviors is largely unexamined and this dissertation is a first step in filling that gap.

Stable isotope analysis of δ15N and δ13C values allow us to interpret the effects of interspecific competition and environmental factors on fishes’ resource use. Saratoga Lake in Wyoming is one of the few locations brook stickleback Culaea inconstans (an invasive species), Iowa darter Etheostoma exile (a species of greatest conservation need), and fathead minnows Pimphales promelas are present. We used stable isotope signatures to investigate the trophic patterns of these species as well as catch rates over time. We sampled Saratoga Lake six times from June through September 2021. Fifteen individuals per species were harvested at each sampling event for stable isotope analysis and the remaining fish were identified, measured, and enumerated. Trends in δ13C data suggest that brook stickleback and fathead minnow exploited pelagic resources while Iowa darter primarily used littoral resources early in the season. However, brook stickleback and fathead minnow switched to use more littoral resources later in the season, coinciding with the timing of a cyanobacterial bloom. Iowa darter catch rate steadily declined over the season while fathead minnow and brook stickleback catch rates did not show directional trends. These results imply that changing habitat conditions and resource availability may potentially increase interspecific competition later in the season, with implications for fish species of greatest conservation need. Furthermore, our findings open the door to further investigation of the effects of cyanobacterial blooms on small-bodied fishes.

Green turtles (Chelonia mydas) perform ocean-crossing migrations, maintain healthy marine ecosystems, generate income through tourism, and are endangered and declining globally. For these reasons, among others, this species has been a focus of numerous research programs worldwide for almost a century. Most of these sea turtle research programs require some form of animal handling to collect the required data (e.g., tagging information or the collection of biological samples). However, this can cause stress, especially for wild animals, and that raises ethical issues. Here, I describe novel methods for assessing and mitigating the effects of handling stress on green turtles. Specifically: (1) I used a combination of animal-borne cameras and drone footage to determine how handling stress altered the post-release behavior of green turtles and (2) I used a photo-ID software to determine whether flipper scales can provide more accurate identifications than the more conventionally used facial scale patterns. I found that turtles spent more time swimming and had shortened dive intervals in the first 30 mins after capture and attachment of a camera than in the hours that follow. Instances of socializing, foraging and resting increased over the 3-3.5 h after release. Animals recorded by drone and not captured were less likely to rest, which suggests this behavior may be a recovery response to handling and/or stress. The same animals were also more likely to socialize. When determining the accuracy of flipper or facial images for photo-ID, I found that head scales provided correct identifications 80% of the time, whereas the flipper provided correct identifications 100% of the time. This implies that researchers could use the flipper instead of more invasive tagging techniques, such as metal flipper tags or using lights to photograph the face for photo-ID, which can induce stress.

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Sleep is widespread across the animal kingdom. However, most comparative sleep data exist for terrestrial vertebrates, with much less known about sleep in amphibians, bony fishes, and invertebrates. There is an absence of knowledge on sleep in cartilaginous fishes. Sharks and rays are amongst the earliest vertebrates, and may hold clues to the evolutionary history of sleep and sleep states found in more derived animals, such as mammals and birds. Here, we review the literature concerning activity patterns, sleep behaviour, and electrophysiological evidence for sleep in cartilaginous (and bony) fishes following an exhaustive literature search that found more than 80 relevant studies in laboratory and field environments. Evidence for sleep in sharks and rays that respire without swimming is preliminary; evidence for sleep in continuously swimming fishes is currently absent. We discuss ways in which the latter group might sleep concurrent with sustained movement, and conclude with suggestions for future studies in order to provide more comprehensive data on when, how, and why sharks and rays sleep.

The ESM file contains additional information about the data analyzed in our review article and a number of extra tables and figures illustrating the results of our semi-quantitative literature search.

Submitted in total fulfillment of the requirements for the degree of Doctor of Philosophy to the School of Agriculture, Biomedicine and Environment, La Trobe University, Victoria.

Submitted in total fulfilment for the degree of Doctor of Philosophy to the Department of Ecology, Environment and Evolution, School of Life Sciences, College of Science, Health and Engineering, La Trobe University, Victoria.

Supplementary Results, Tables and Figures

Recent studies have revealed that fecal microbiota transplantation exerts beneficial effects on modulating stress-related inflammation and behavioral disorders in mammals. The aim of this study was to examine if cecal microbiota transplantation (CMT) presents similar efficiency in improving the health status and reducing aggression in egg-laying strain roosters. Cecal contents were collected from the divergently selected 63 (gentle) and 72 (aggressive) chicken lines based on resistance or susceptibility to Marek���s disease, resulting in line���s unique physiological and behavioral characteristics. Eighty-four 1-d-old male chicks of Dekalb XL strain were randomly assigned into 3 treatments with 7 replicates per treatment of 4 birds per replicate: CTRL (0.1 ml of saline), 63-CMT (0.1 ml cecal solution of line 63), and 72-CMT (0.1 ml cecal solution of line 72) for a 16-wk trial. Cecal microbiota transplantation was conducted once daily from d 1 to d 10 and then boosted once weekly from wk 3 to wk 5. At wk 5, 11, and 16, body weight and blood samples were collected for detecting CMT-induced physiological changes of recipient birds. Samples of the spleen, ileum, hypothalamus, and cecal contents were collected at wk 5 and 16. Behavioral data was analyzed at the same time points. The results indicated that transplantation altered the structures and diversity of the gut microbial community in recipient birds, which led to differences in performance traits, neuroendocrine and immune systems, and exhibition of aggression. Compared to CTRL birds, 72-CMT birds had better nutrient digestion and absorption but lower stress adaptive capacity at wk 5, while 63-CMT birds had reduced systemic inflammation resulting from the up-regulation of anti-inflammatory cytokine IL-10, together with down-regulation of pro-inflammatory cytokines TNF-�� and IL-6 at wk 16. In addition, CMT induced a lower frequency of aggression with a higher hypothalamic serotonergic activity in 63-CMT birds at wk 5. Meanwhile, genus Ruminococcaceae UCG-005 was found to be positively correlated with brain serotonin levels (P < 0.05) in 63-CMT birds, while genus GCA-900066225 was negatively correlated with 5-HIAA (P < 0.05) in 72-CMT birds at wk 5. Taken together, early postnatal CMT in recipient birds induces donor���s line-related effects on performance traits, stress adaptive capability, aggressive behavior, immune and neuroendocrine functions through regulating the gut-microbiota-brain and gut-microbiota-immune axes. The findings may provide new insights into developing management methods for controlling aggressive behavior in poultry.

Management of predation on sea turtle nesting beaches is vital to conservation efforts for the vulnerable loggerhead turtles (Caretta caretta) and olive ridley turtles (Lepidochelys olivacea). Sea turtles increasingly face threats from invasive and human-tolerant mammalian predators as human disturbances on nesting beaches rises. The intensity of mammalian predation has increased in Las Baulas National Park in Costa Rica which is an important nesting site for several species of threatened and endangered sea turtles. I analyzed loggerhead and olive ridley nest predation on four beaches in the United States and Costa Rica that were chosen for variations in degree of human disturbance and management strategies. My objectives were to 1) determine if egg predation rates differ at the four sites, 2) determine the most destructive predators at each location, and 3) suggest management options to alleviate mammalian threats to turtle clutches on Playa Grande and Playa Cabuyal in Costa Rica. My results show that the beaches without a nest protection or predator control program had very high rates of predation. Invasive mammalian predators and mammalian predators associated with human disturbance were the most destructive at the four sites. I recommend that regulations regarding dogs and the take of eggs from the beach are enforced at Playa Cabuyal and that physical nest protection is rapidly implemented at Playa Grande. I also recommend that the National Park consider managing raccoon predation by removing problem individuals, but caution that they do so in a way that maintains the animals’ role in the ecosystem.

© Murray–Darling Basin Authority for and on behalf of the Commonwealth of Australia. With the exception of the Commonwealth Coat of Arms, the Murray–Darling Basin Authority logo and The Murray–Darling Freshwater Research Centre logo, all material presented in this document is provided under a Creative Commons Attribution 3.0 Australia licence (http://creativecommons.org/licences/by/3.0/au/).

Exposure to thermal stress can negatively impact an animals' overall welfare, resulting in decreased body condition, lower reproductive success, and in severe cases, mortality. The swine industry has prioritized efficient production and as a result has gained rapid improvements in lean growth and increase litter sizes. Unfortunately, modern swine are unable to cope with the negative effects of heat stress. Thus, it is crucial to understand the preferred temperature of swine to create recommendations on when to initiate mitigation strategies to combat the negative effects of thermal stress. However, several different factors contribute to an animals' thermal comfort and thermal preference will differ based on age, reproductive stage, social context, early life thermal stress, and behavior. Thus, making it exceptionally difficult to classify an animal's thermal comfort zone. These studies aim to highlight how those factors influence thermal comfort in pigs and help guide recommendation polices for housing pigs in their preferred temperatures.

Supplementary text, Tables S1-S13, Figures S1,S2

Sexual conflict arises in biparental species because of the fitness payoffs of shifting the costs of care onto their partner. The negotiation model asserts that parents actively monitor their partner’s level of investment and adjust their own in response generally resulting in partial compensation when a member of the pair reduces their level of investment. The willingness of one parent to compensate for the other’s change is found to be widely variable. Habitat or resource quality available to pairs may explain such variation. It is predicted that the level of compensation by one partner will increase with decreasing resource quality. I tested this prediction with the biparental burying beetle, Nicrophorus orbicollis. Under natural conditions, burying beetles apply costly social immune molecules to carcasses of small vertebrates to preserve nutritional value for young. The goals of this research were (1) to determine if males immunologically compensate when females are immunologically handicapped; and (2) determine the impact of resource quality on compensation. Changes in lysozyme-like-activity (LLA) and phenoloxidase (PO) production in oral and anal secretions were used to quantify social immune investment. Pairs were provided a mouse carcass of one of three qualities: freshly thawed, aged for 3 days, or aged for 7 days. As expected, female LLA decreased once injected with lipopolysaccharide (LPS) irrespective of carcass quality. Injections caused significant down regulation of oral PO in females. Male LLA increased as the quality of carcasses decreased when paired with handicapped females. Males showed no changes in PO across treatments or carcass types. My results demonstrate that males compensate for a change in maternal investment and the level of compensation increases as resource quality decreases.

Data on the tethered flight of oriental fruit flies, Bactrocera dorsalis, in relation to age, sex and body mass at different temperatures.

Pathogens and parasites are increasingly recognized as important components within host populations, communities, and ecosystems. Parasite contributions to ecosystem function most likely manifest as density-mediated impacts of parasites on their hosts, the direct contributions of parasite biomass to a system, and via parasite-induced changes in host behavior and physiology (trait-mediated impacts). Here, a framework was constructed that can be used to conceptualize parasite contributions to ecosystem function (Chapter 1). Then the influence of parasite attack on host movement was explored to further evince the mechanistic underpinnings of trait-mediated parasite impacts (Chapter 2). Additionally, mesocosms were created across a gradient of parasitism to examine how these mechanisms are likely to unfold at larger biological scales (Chapter 3). Lastly, a series of differential equations was created to model host-parasite-ecosystem interactions and generate theoretical predictions about how and when parasites are likely to influence ecosystem processes (Chapter 4). Parasites have many characteristics of ecosystem engineers, but their role has historically been ignored. These studies begin to explore the role that parasitism may have as one of the drivers of ecosystem processes.

In group-living animals social information is essential to survival, providing indirect information about the environment, such as predator presence. An individual’s ability to acquire social information is mediated by its sensory system. In visually-oriented species, different visual dimensions provide rapid information about conspecifics. However, we know relatively little about how the uptake of visual social information mediates the formation of coordinated patterns of group movement, referred to as collective behavior. Using two species of birds (i.e., European starling (Sturnus vulgaris) and red-winged blackbird (Agelaius phoeniceus)) and fish (i.e., zebrafish (Danio rerio) and golden shiner (Notemigonus crysoleucas)), I determine how the structure of social interactions are facilitated by the capabilities imposed by the visual system from a theoretical point of view. With a focus on zebrafish (Danio rerio), a visually-oriented, social cyprinid, I further explore the role of vision in mediating social interactions. Specifically, I characterize several relevant visual dimensions in zebrafish that have the potential to influence the uptake of social information: visual coverage, visual resolution and visual contrast. With insights gained from theoretical modelling and a series of behavioral experiments, I discuss the constraints that these visual dimensions might impose on social interactions and develop predictions for collective behavior.

Human society is presently beset by an array of anthropogenic social-ecological crises that threaten the sustainability of the social-ecological systems that sustain our livelihoods. While research alone will not rectify these issues, it can help to answer key questions that must be addressed to develop effective solutions. To address such questions in a cohesive, compelling manner, social-ecological research can be bounded, structured, and distilled through innumerable organizing principles or theoretical frameworks. For this dissertation, I focused on the geographic region of Tierra del Fuego and sought to draw from the array of disciplines and methods that use sound as a lens for biological, ecological, and/or social inquiry. I also endeavored to consider various temporal, spatial, and organizational scales while investigating a selection of topics with a) specific importance in the social-ecological systems of Tierra del Fuego and b) general relevance to global social-ecological challenges. Chapter 1 provides an introduction to the dissertation, and Chapter 6 serves as a conclusion. The objective of Chapter 2, “Biogeographical and analytical implications of temporal variability in geographically diverse soundscapes”, was to provide some guidance to passive acoustic monitoring (PAM) practitioners on how to design appropriate temporal sampling schemes based on the temporal variability of the sounds one wishes to measure and the power and storage limitations of acoustic recorders. We first quantified the temporal variability of several soundscape measurements and compared that variability across sites and times of day. We also simulated a wide range of temporal sampling schemes in order to model their representativeness relative to continuous sampling. For Chapter 3, “Sentinels for sentinels: passive acoustic and camera trap monitoring of sensitive penguin populations”, we tested the utility of PAM to monitor behavior and abundance of Magellanic (Spheniscus magellanicus) and southern rockhopper penguins (Eudyptes chrysocome) at different spatial and temporal scales. We conducted in situ observations of the acoustic behavior of each species, and we compared acoustic metrics with penguin counts from narrowly focused camera traps and larger-extent observations of colony density. Chapter 4, “Acoustic monitoring shows invasive beavers (Castor canadensis) increase avian diversity in Tierra del Fuego”, is focused on impacts of the invasive North American beaver (Castor canadensis) on Fuegian bird communities. We sought to determine how bird communities might differ between intact riparian forests, beaver ponds, and beaver meadows created by pond drainage. We conducted PAM and classic avian point counts under each of these conditions across seasons to test for differences between impact conditions and to compare the two methodologies. For Chapter 5, “Human-nature connection and soundscape perception: insights from Tierra del Fuego, Argentina”, we evaluated the relationship between soundscape perception and nature relatedness by conducting surveys and soliciting responses to soundscape audio prompts. We also examined the potential for any demographic influences on nature relatedness or soundscape perception in the context of local social tensions.

Data for an upcoming publication:Tess Laidlaw, Tobias E. Hector, Carla M. Sgrò, and Matthew D. Hall. Pathogen exposure limits the expression of sexual dimorphism in a host’s thermal limits.Files in this package:Title: Laidlaw_limits.csvDescription: Data for the knockdown times (in minutes) for male and female Daphnia exposed to a 37°C static heat shock. Listed are each individual ID (indv_id), the sex of the host (sex, M = Male or F = Female), the host genotype (host, H2 = HU-HO2 or M1 = BE-OMZ-M10), the pathogen genotype or treatment (pathogen, C1, C14, C20 or CTRL = Unexposed Controls), and the knockdown times (death_time_min).Title: Laidlaw_spores_reg.csvDescription: Data for estimating the partial effects of spore loads and relative body size on the change in knockdown times of infected animals. Relative measures of upper thermal limits and body size were calculated by subtracting the corresponding control group means from each individual observation (i.e., sex- and genotype-matched). Listed are each individual ID (indv_id), the sex of the host (sex, M = Male or F = Female), the host genotype (host, H2 = HU-HO2 or M1 = BE-OMZ-M10), the pathogen genotype (pathogen, C1, C14, C20), time to death relative to unexposed controls (rel_death_time), body size relative to unexposed controls (rel_size) and log10 of spore loads (log_spores).

With a stable center of mass, pneumatic-aided movement, and the ability to scale multiple terrain types, the uniquely efficient and lightweight form of spiders has changed the way we think about robotic design. While the number of papers on arachnid biomechanics and spider-based biomimetic robots has been increasing in recent years, the style of analysis and the motion-types analyzed have barely changed since the 1980s. Current analyses are based on a force plate and treadmill design, in which the spider is induced into an escape run. This environmental change can affect the movements of the spider. Here I propose a novel method of testing the biomechanical and kinematic properties of spiders using a tank with a built-in sensor matrix which allows for a more natural environment for the specimens and provides force data from individual legs. The system detects a minimum force of .0196 N and has a sampling rate of 1,000 samples /second, which allows for the analysis of forces during the step. Aphonopelma seemanni, a tarantula commonly used in such research, but whose forces during movement have to date not been analyzed, was recorded walking across the matrix, and the forces, step patterns, joint angles, and center of mass deviations were recorded. Walking indicated significantly different step pattern traits than current literature, and forces per leg (.07281 N±.0235) recorded were much smaller than expected in comparison to other spiders. Statistical analysis also indicated no changes in walking movement over a range of temperatures, which also varies from literature. These findings indicate that further research on spiders should be done with respect to walking gaits in order to improve upon current biomimetic models.

The overall aim of this thesis was to investigate the impacts of environmentally realistic exposure to fluoxetine, an antidepressant, on ecologically important behavioural and physiological traits in freshwater fish (mosquitofish, Gambusia holbrooki and guppies, Poecilia reticulata). Specifically, in this thesis the impacts of fluoxetine on behavioural traits linked to anxiety, sociability, reproduction and foraging, as well as physiological traits related to health and reproduction were assessed.

In dense mating aggregations, such as insect and anuran choruses, signals produced at the same time can overlap and interfere with one another, reducing the ability of receivers to discriminate between individual signals. Thus, evolution by sexual selection is expected to result in mating signal timing strategies that avoid overlap. Patterns of signal alternation between competing males are commonly observed in leks and choruses across taxa. In some species, however, signalers instead deliberately overlap, or ‘synchronize’, their mating signals with neighboring conspecifics. Given the assumed high cost of reduced mate attraction when signals overlap, mating signal synchronization has remained an evolutionary puzzle. Synchronization may be beneficial, however, if overlapping signals reduce the attraction of nontarget receivers (predator avoidance hypothesis). Synchronized signals could also constructively interfere, increasing female attraction to the mating aggregation (the beacon effect hypothesis). I investigate these functions of synchronized signaling in two species of tree frogs that synchronize their mating calls: the pug-nosed tree frog (Smilisca sila) and the Ryukyu Kajika frog (Buergeria japonica). To examine the trade-offs imposed by call synchronization in each species, I conduct a series of field and laboratory playback experiments on target (female frogs) and nontarget (eavesdropping predators) receivers of frog calls. Results from these experiments support both hypotheses, suggesting that synchronized frog calls can reduce the attraction of predators and attract mates to the chorus. In addition, I found reduced preferences for fine-scale call timings in female S. sila and B. japonica, deviating from the expected preferences observed in many other anuran and non-anuran species. Thus, while males may enjoy multiple benefits from synchronized mating signals, relaxed sexual selection for non-synchronous signals may be key to the evolution and maintenance of mating signal synchrony.

2019 Annual Forum presentation - overview of the research delivered over the five year EWKR project

Echolocating animals that forage in social groups can potentially benefit from eavesdropping on other group members, cooperative foraging or social defence, but may also face problems of acoustic interference and intra-group competition for prey. Here, we investigated these potential trade-offs of sociality for extreme deep-diving Blainville′s and Cuvier's beaked whales. These species perform highly synchronous group dives as a presumed predator-avoidance behaviour, but the benefits and costs of this on foraging have not been investigated. We showed that group members could hear their companions for a median of at least 91% of the vocal foraging phase of their dives. This enabled whales to coordinate their mean travel direction despite differing individual headings as they pursued prey on a minute-by-minute basis. While beaked whales coordinated their echolocation-based foraging periods tightly, individual click and buzz rates were both independent of the number of whales in the group. Thus, their foraging performance was not affected by intra-group competition or interference from group members, and they did not seem to capitalize directly on eavesdropping on the echoes produced by the echolocation clicks of their companions. We concluded that the close diving and vocal synchronization of beaked whale groups that quantitatively reduces predation risk has little impact on foraging performance.

The research conducted by the MDB EWKR Waterbird Theme has produced new information to assist managers to better target water, vegetation and waterbird management to ensure ‘event readiness’ at sites between flooding events and to maximise recruitment. Maximising recruitment into the adult population depends on optimising the number of birds that nest, the number of chicks that fledge from each site, and the survival of those birds as juveniles, sub-adults and breeding adults. Information is needed quantifying these variables and what affects them – however the mobility of waterbirds and lack of information on their movements makes this difficult. Therefore, the MDB EWKR Waterbird Theme research activities included: detailed movement and habitat-use studies of individual birds over the duration of the EWKR project using tracking devices (satellite GPS transmitters); motion-sensing and time-lapse camera nest monitoring; on-ground tagged-nest and water depth monitoring; colony mapping; analysis of chick diet and energy sources; and modelling of chick energy requirements.

The microbiome plays a key symbiotic role in maintaining host health and aids in acquiring nutrients, supporting development and immune function, and modulating behavior. However, more research is needed to elucidate the potential impact of environmental pollutants on host microbial communities and how microbiomes can modulate the toxicity of contaminants to the host. Through a literature review of 18 studies that assessed the impacts of various anthropogenic chemicals on fish-associated microbiomes, we found that toxicants generally decrease microbial diversity, which could lead to long-term health impacts if chronically stressed, and can increase the host’s susceptibility to disease as well as the chemical resistance of certain microbes. These findings led us to explore the impacts of one of the reviewed contaminants, polycyclic aromatic hydrocarbons (PAHs), typically found in oil. The Deepwater Horizon disaster of April 2010 was the largest oil spill in U.S. history and had catastrophic effects on several ecologically important fish species in the Gulf of Mexico (GoM). This study tested the hypotheses that exposure to weathered oil would cause significant shifts in fish gut-associated microbial communities, with taxa known for hydrocarbon degradation increasing in abundance and that foraging behavior would decrease, potentially due to microbial dysbiosis via the gut-brain axis. We characterized the gut microbiome (with 16S rRNA gene sequencing) of a native GoM estuarine species, the sheepshead minnow (Cyprinodon variegatus). Fish were exposed to High Energy Water Accommodated Fractions (HEWAF; tPAH = 80.99 ± 12.5 μg/L) of oil over a 7-day period and whole gastrointestinal tracts were sampled for microbiome analyses. A foraging behavioral assay was used to determine feeding efficiency before and after oil exposure. The fish gut microbiome did not experience any significant changes in alpha or beta diversity but known hydrocarbon degrading taxa were noticeably present in oil-exposed communities and were absent in controls. We found the order Pseudomonadales, the family Paenibacillaceae, and Pseudomonas pachastrellae to be among these, with Pseudomonadales increasing in abundance. Foraging behavior was not significantly affected by oil exposure. This work highlights the need for further research to elucidate the functional metagenomic responses of the fish gut-microbiome under oil spill conditions.

Understanding and adequately protecting habitat is at the forefront of modern conservation concerns. Turtles are especially vulnerable to habitat loss, and are therefore a top priority for habitat research. To help meet this need, I used radio telemetry to collect microhabitat data from two imperiled species of turtles that occupy a military base in Michigan. Preliminary data exploration was carried out with principal components analysis (PCA). Microhabitat use was then modeled for each species using conditional logistic regression (CLR), with a generalized estimating equation (GEE) element to limit bias due to individual variation. Finally, I compared habitat use between sympatric Blanding’s and Wood Turtles using Mann-Whitney U tests and Mood’s median tests to investigate the degree of overlap in microhabitat use when these species occur in sympatry. Evidence for microhabitat selection in Blanding’s Turtles was weak, suggesting that they likely do not make habitat decisions at this level. Wood Turtles selected sites that were farther from water and had fewer trees, less overstory canopy cover, and more ground cover. Additionally, the two species differed in several aspects of microhabitat use; Wood Turtles were more terrestrial and more tolerant of tree cover than Blanding’s Turtles. Patterns of microhabitat use found in this study match previously observed behavior of turtles in high quality habitat, suggesting that managers should work to maintain the habitat currently available at Camp Grayling. Additionally, because both turtle species were associated with open canopy, selective logging could benefit turtles provided care is given to timing and methods.

Appendix A1.1 The influence of flow and non-flow related stressors on the drivers of fish recruitmentAppendix A1.2 Prioritising fish research for flow management in the Murray-Darling BasinAppendix A1.3 Riverscape recruitment: a conceptual synthesis of drivers of fish recruitment in riversAppendix A1.4 Examination of the relationship between food density, temperature and early-life stage growth and survivalAppendix A1.5 Understanding the feeding requirements of larval fish in the northern Murray–Darling BasinAppendix A1.6 Comparison of the thermal and nutritional regimes among main channel and floodplain habitat patchesAppendix A1.7 The relationship between discharge, reach hydraulic complexity, zooplankton production and retention in a lowland river systemAppendix A1.8 Investigating the relationship between flow, structural habitat, hydrodynamics and patterns of larval settlement and retentionAppendix A1.9 Water infrastructure and challenges for fish conservation: A trait-based analysis to foresee fish recruitment in regulated riversAppendix A1.10 Basin-scale population dynamics of Golden Perch and Murray Cod: relating flow to provenance, movement and recruitment in the Murray–Darling BasinAppendix 2: Theme Data InventoryAppendix 3: Theme OutputsAppendix 4: Theme Engagement and Communications Activities

MMCP Collaboration (MMCP) is a project supported by the Joint State Governments and the Murray-Darling Basin Authority to generate and adopt freshwater ecological knowledge through collaboration, to maintain research capability and contribute supporting science to underpin the Basin-Wide Watering Strategy.

Laboratory animal welfare is critically influenced by personnel working with animals through their decisions about housing, management, and enrichment of these animals. In particular, human-animal interactions can have major impact on both animals and research results. The first step in better understanding their effects is to define terminology, theories, and general applications (Chapter I). Rats are commonly used as model in laboratory research and have been shown to experience stress even during routine handling. A handling technique called heterospecific play or “rat tickling”, which mimics aspects of rat rough-and-tumble play, has the potential to minimize stress, enrich a rat’s life, and improve their welfare. Unfortunately, a survey of 794 laboratory personnel shows rat tickling implementation to be low (Chapter II). Commonly cited barriers to rat tickling includes a lack of time, difficulty with personnel (attitudes and training), and research factors. However, personnel were more likely to tickle their rats if they were more familiar with the practice, thought it was both good and under their control, and felt subject to social pressure to provide it. They also were more likely to tickle their rats if they wanted to provide more enrichment and generally had more positive behaviors towards laboratory animals.Using those findings, an attempt was made to address those barriers to rat tickling implementation. Chapter III focuses on the barrier of time. This project compared the effectiveness of tickling rats for 15, 30 or 60 s for 1, 3, or 5 days. After the final day of tickling, rats were assessed for their in-cage behavior, human approach behavior, fecal corticosterone, and reaction to an intra-peritoneal injection. Results showed that the most time-efficient and effective rat tickling dosage is 15 s for 3 days before any aversive procedures, based on increased production of 50-kHz ultrasonic vocalizations (a measure of positive affect) and positive anticipatory behavior. Chapter IV focuses on the barrier of inadequate training. This project compared training laboratory personnel with online-only training or online + hands-on training as compared to a waitlist across 2.5 months. Results indicated that both training modalities increased personnels’ reported correct implementation of tickling, self-efficacy, knowledge, and familiarity with rat tickling. Hands-on training also increased personnel’s feelings of control related to rat tickling. Overall, this dissertation identified barriers to rat tickling and then attempted to address the barriers of time and beliefs/training to increase implementation of best practices of rat tickling to improve rat welfare.

MMCP Collaboration (MMCP) is a project supported by the Joint State Governments and the Murray-Darling Basin Authority to generate and adopt freshwater ecological knowledge through collaboration, to maintain research capability and contribute supporting science to underpin the Basin-Wide Watering Strategy.The Fish movement theme is one of five themes that make up MMCP. This project aimed to increase the capacity of training lock staff to tag fish with automated transponders, to increase available data on fish movement. This document outlines the equipment, procedures and handling of data for lock staff to undertake PIT tagging fish after initial training.

Prehistoric demography has recently risen to prominence as a potentially explanatory variable for episodes of cultural change as documented in the archaeological and ethnographic record. While this has resulted in a veritable boom in methodological developments seeking to address temporal changes in the relative size of prehistoric populations, little work has focused on the manner in which population dynamics manifests across a spatial dimension. Most recently, the so-called Cologne Protocol has led the way in this field. However, strict requirements of raw-material exchange data as analytical inputs have prevented further applications of the protocol to regions outside of continental Europe. We apply an adjusted approach of the protocol that makes it case transferable to other parts of the world, while demonstrating its utility by providing comparative benchmarks of previous research on the Late Glacial Final Palaeolithic of southern Scandinavia, and novel insights from the early Holocene pioneer colonization of coastal Norway. Although our results (re)demonstrate that population levels were low and occasionally hovered just above potential viability thresholds, we consider the estimates on population densities as having a much stronger and, occasionally, more negative effect on episodes of cultural change as testified in the regional archaeological records.This article is part of the theme issue ‘Cross-disciplinary approaches to prehistoric demography’.

Appendix 1 McGinness, H. M. (2016) Waterbird responses to flooding, stressors and threats. CSIRO, Australia. Technical literature review report. Appendix 2 McGinness, H.M., Langston, A., Robinson, F., Piper, M., Martin, J., Doerr, V.A.J., Kingsford, R., and Mac Nally, R. Satellite-tracking ibis and spoonbill movements and habitat choices. Appendix 3 McGinness, H.M., Robinson, F., Piper, M., and Hodgson, J., Kingsford, R., Mac Nally, R. and Doerr, V.A.J. Quantifying ibis and spoonbill egg and chick survival rates and mortality drivers using motion-sensing and time-lapse cameras. Appendix 4 Brandis, K., Bellio, M., Callaghan, D., Webster, E., Francis, R. Monitoring ibis and spoonbill nest success through on-ground tagged nest and water depth monitoring.Appendix 5 Brandis, K., McCann, J., Lyons, M. Ibis and spoonbill nest and colony mapping using drone imagery.Appendix 6 Ibis and spoonbill chick energy source assimilation. Current authors include: Paul McInerney, Kate Brandis, Heather McGinness, Ralph Mac Nally. Appendix 7 O’Brien, L. and McGinness, H.M. (in review) Ibis and spoonbill chick energy requirements: Implications for wetland management. Appendix 8 Lucy Wenger and Heather McGinness (2018) Waterbird Chick Development: A Visual Guide to Selected Australian Species. CSIRO, Australia. Appendix 9 Webster, E. (2017) Similarities and differences in breeding ecology of straw-necked ibis Threskiornis spinicollis and Australian white ibis T. moluccus in response to environmental flows. Honours thesis, UNSW. Appendix 10 Theme Data InventoryAppendix 11 Theme OutputsAppendix 12 Theme Engagement and Communications Activities

The American crocodile (Crocodylus acutus) is a common resident of Central American waterways, with one of the largest ranges of all crocodilians. It is very salt-tolerant, with only Nile crocodiles and Saltwater crocodiles superseding it in terms of being the most saline tolerant. Globally it has lost 9% of its range, with habitat destruction and fragmentation as the leading threat to this species. Overall there is a great need to understand the habitat uses by this species in order to mitigate consequences of further anthropogenic incursions along its range. Thus, this study aims to investigate seasonal effects of salinity on habitat selection of American crocodiles in a natural mangrove habitat, and to validate use of a commercial drone as a surveying tool for crocodilians in such habitats. This study found that as the seasons shift from wet to dry there was an associated increase in salinity of the estuarine waterway that resulted in an increase in the halocline of the estuary waters the greater the distance from the ocean. When broken down into the following groups: Hatchlings and juveniles (HJ) vs subadults and adults (SbA) it was found that salinity as well as season both had a correlation with the presence of crocodiles from the HJ group (p Surveys taken via drone were as efficacious as surveys taken diurnally via boat, with a survey encounter rate of 0.40 km-1, but still less efficacious than nocturnal eyeshine surveys, which had an encounter rate between 1.2 – 2.9 km-1. The drone was able to identify animals that were submerged under water, but was unable to ID animals resting on banks in thick mangroves. However, the drone was able to identify crocodiles as small as 0.7m. Further, the drone showed encounter rates for sharks and rays that were much higher than crocodiles, 0.84km-1 and 0.64km-1 respectively.

Published manuscript

Biodiversity loss is the silent crisis of the 21st century. Human activities are drastically altering the diversity of life on Earth, yet the extent of this transformation is shrouded by our limited information on biodiversity and how it is changing. Emerging technologies may be suited to fill this information gap, and as a result increase our capacity to measure and manage natural systems. Acoustic monitoring is a remote sensing technique that is rapidly reshaping the temporal and spatial scales with which we can assess animal biodiversity. Through recording and analyzing soundscapes—the collection of sounds occurring at a given place and time—we can assess biodiversity, habitat condition, and environmental change. However, the relationships between soundscapes and these three ecological dimensions are still in the early phases of categorization, especially in aquatic systems. This dissertation investigates how soundscapes can be used to measure biodiversity, habitat condition, and environmental change in aquatic habitats. It addresses several knowledge gaps: First, I develop a framework for classifying unknown sounds within a soundscape, which I use to measure the acoustic diversity and dynamics within a tropical freshwater wetland. Second, I demonstrate that soundscapes can reflect the resilience of animal communities following disturbance events. Altered soundscapes revealed that Hurricane Maria, which swept through Puerto Rico in September 2017, impacted dry forest animal communities more than adjacent coral reef communities. Third, in kelp forest habitats off the coast of California, USA, I showed that soundscape variables correlated with ecological variables associated with regime shift in kelp forests, including urchin density, kelp cover, and fish diversity. Overall, this dissertation demonstrates that soundscape recording and analysis is a promising way to assess the ecological conditions of aquatic systems.

This thesis explores how people value the welfare of dogs and what they think is important to the welfare of dogs living in kennels. This research shows that young working dogs find training kennel facilities to be stressful. Access to an enrichment program did not increase stress and may help young working dogs to complete their training. The research also identified better ways to measure stress in dog welfare research using salivary cortisol. The thesis proposes that assuring the public that working dogs have good welfare will be important to the sustainability of relevant industries.

Exposure to psychosocial stress is known to precipitate the emergence of stress related psychiatric disorders such as depression and anxiety. While mechanisms by which this occurs remain largely unclear, recent evidence points towards a causative role for inflammation. Neurotransmitters, such as norepinephrine (NE) are capable of regulating expression of proinflammatory cytokines and thus may contribute to the emergence of stress-related disorders. The locus coeruleus (LC) is the major source of norepinephrine (NE) to the brain and therefore the current study utilized N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4), an LC selective noradrenergic neurotoxin, to determine the discrete involvement of the LC-NE system in social defeat-induced inflammation in LC projection regions including the central amygdala (CeA), dorsal raphe (DR) and plasma. In the current study, rats were exposed to brief social defeat or control manipulations on 5 consecutive days. To determine whether a history of social defeat enhanced or “primed” the inflammatory response to a subsequent defeat exposure, all rats regardless of stress history were exposed to an acute social defeat challenge immediately prior to tissue collection. As anticipated, prior history of social defeat primed inflammatory responses in the plasma and CeA while neuroinflammation in the DR was markedly reduced. Notably, DSP-4 treatment suppressed stress-induced circulating inflammatory cytokines independent of prior stress history. In contrast, neuroinflammation in the CeA and DR were greatly augmented selectively in DSP-4 treated rats with a history of social defeat. Together these data highlight the dichotomous nature of NE in stress-induced inflammatory priming in the periphery and the brain and directly implicate the LC-NE system in these processes.

Focusing on species of fish where males provide all of the parental care this thesis examines the conditions that lead to fathers eating their own offspring. It also investigates whether parental status influences male courtship behaviour. It finds that males are more likely to eat their own young when they will be costly to raise, and, in some instances, where doing so can help the male breed again. However, males did not adjust their courtship behaviour immediately after acquiring a clutch of eggs. Together, these findings highlight the complexity and variability in mating and parental effort among paternal caring species.

Injurious pecking is one of the major welfare concerns for poultry and other captive birds. Injurious pecking behavior can result in welfare problems including feather and skin damage, pain, substantial heat loss because of feather loss, and even death of the recipient bird. Injurious pecking can also cause economic losses because of reduced production efficiency, increased mortality and reduced feed conversion ratio. Injurious pecking behavior includes feather pecking, feather picking, cannibalism and aggressive pecking. Feather pecking, when a bird uses its beak or bill to peck at the feathers of another bird, can be categorized as either gentle feather pecking (repeated and light pecks) or severe feather pecking (singular and hard pecks). Feather picking is described as a self-damaging behavior that occurs in psittacine species such as parrots and also in ducks. Cannibalism is classified as either tissue pecking (persistently forceful pecks directed at exposed skin) or vent pecking (pecks directed at the top of cloaca or below the cloaca). Unlike feather pecking, feather picking and cannibalism, which are not associated with aggression, aggressive pecking establishes and maintains the dominance hierarchy. Limited studies have examined injurious pecking of Pekin ducks, but results from previous research examining duck picking behavior and feather quality suggested that ducks pick mostly at themselves and that the development of picking is related to feather growth and worsens with age. Scant information is available regarding the prevalence of injurious pecking behavior and characteristics of the behavior. To address some of the gaps in the knowledge regarding injurious pecking behavior of ducks, this study examined 1) age-related changes in frequencies and durations of preening behavior and injurious pecking behavior of Pekin ducks, including self-picking and feather pecking; 2) the body locations most frequently affected, and whether feather removal and feather eating occurred concurrently with injurious pecking; 3) the prevalence of injurious pecking behavior; and 4) age-related changes in duck welfare that may be associated with injurious pecking. Information about preening behavior was recorded because injurious pecking and preening behavior may have similar age-related patterns, as previous studies have suggested that increased levels of preening behavior are related to feather growth. Data were collected on 5 commercial duck flocks on 5 farms. Welfare data were collected from all 5 flocks and behavior data were collected from 2 of the 5 flocks. For the two flocks, duck behavior was video-recorded over two consecutive days at 20-22d (Period 1), 27-29 d (Period 2), and 34-36 d (Period 3). Scan sampling and focal animal sampling were used to analyze the video recordings and determine the frequencies and durations of injurious pecking behavior (gentle feather pecking, severe feather pecking, self-picking and aggressive pecking). For scan sampling, the percentage of ducks performing injurious pecking behavior were recorded every 30 min from 0900h to 1500h. For both scan and focal animal sampling, the viewing area of each camera installed in the barn was divided into eight equal squares (observation areas), of which four were randomly selected for analysis. For focal animal sampling, one duck was randomly selected from each observation area and observed for 30 min from 0945h to 1015h and 1345h to 1415h ((n=8 ducks per camera (4 ducks in the morning and 4 ducks in the afternoon) and n=24 ducks per barn)) to determine the duration and frequency of injurious pecking behavior and preening behavior. For all five flocks, duck welfare (feather quality, feather cleanliness, nostril cleanliness, eye condition, footpad condition and gait) was assessed in 100 ducks from each flock between 17-18 d (Period 1), 29-30 d (Period 2), and 36-37 d (Period 3). Welfare data and frequencies of behaviors from focal animal sampling were analyzed using the GLIMMIX procedure (SAS 9.4). Scan animal sampling data and behavioral durations from focal animal sampling data were analyzed using the MIXED procedure (SAS 9.4). The most frequently observed form of injurious pecking behavior was gentle feather pecking, which increased from Period 1 to Period 2 (P < 0.001), then declined from Period 2 to Period 3 (P < 0.001). Gentle feather pecking was most frequently directed at the tail, wings and back. Removal of feathers was observed 13 times, and feathers were eaten 7 times in the 6 days of video observation. Ducks’ eye condition, feather cleanliness under the tail, and feather quality on all the assessed body locations, except for the neck, worsened with age. Age was a major factor affecting the development of injurious pecking behavior including the proportion of ducks performing gentle feather pecking behavior (P < 0.001), frequency and duration of gentle feather pecking behavior (frequency: P < 0.001; duration: P < 0.001), and other injurious pecking behavior (frequency: P = 0.038; duration: P = 0.036). From scan sampling, 1.85% of the ducks were observed performing severe feather pecking behavior, 6.84% of the ducks were observed performing aggressive pecking behavior, and no duck was observed performing self-picking behavior in the total of 1082 ducks performing injurious pecking behavior across the 3 periods. From focal sampling, 83.33% of the ducks were observed performing gentle feather pecking behavior, 13.89% of the ducks were observed performing severe feather pecking behavior, 16.67% of the ducks were observed performing aggressive pecking behavior, and only 1.39% of the ducks were observed performing self-picking behavior of the total of 288 ducks observed. Frequency and duration of preening behavior increased from Period 1 to Period 2 (frequency: P = 0.004; duration: P < 0.001), then declined from Period 2 to Period 3 (frequency: P < 0.001; duration: P < 0.001). In conclusion, feather pecking between conspecifics was the most frequently performed pecking behavior of commercial Pekin ducks. Age was a major factor affecting the development of pecking behavior, which peaked at 27-29 d. The body locations that injurious pecking behaviors were most frequently directed at were the tail, wings and back, consistent with the welfare condition results that indicated a worsening tail, wing and back feather quality with age. Feather removal and feather eating were infrequently observed, which might indicate that injurious pecking behavior in Pekin ducks is not for the purpose of pulling out and eating the feathers. The frequency and duration of gentle feather pecking and preening behavior followed a similar pattern with age; however, further research is needed to evaluate whether these behaviors are associated. This study provided more details about age-related changes in injurious pecking behavior and welfare of commercial Pekin ducks. However, further work is needed to investigate specific causes of and methods to reduce injurious pecking behavior of Pekin ducks.

Elaborate ornamentation is often assumed to improve reproductive success of the bearer, by attracting mates or deterring rivals. In particular, bright plumage in birds may signal the quality of an individual, provided that its production and maintenance are costly. Seasonal plumages, i.e. the alternation of dull non-breeding plumage and colourful breeding plumage, have the potential to do so through multiple components; however, the nature and magnitude of their benefits and costs remain ill-understood, particularly for species that form monogamous, year-round and long-term partnerships. Here I investigate the function of male seasonal plumages in the genetically monogamous purple-crowned fairy-wren, Malurus coronatus.

Both mammals and birds exhibit two sleep states, slow wave sleep (SWS) and rapid eye movement (REM) sleep. Studying certain aspects of sleep-related electrophysiology in freely behaving animals can present numerous methodological constraints, particularly when even fine body movements interfere with electrophysiological signals. Interestingly, under light general anesthesia, mammals and birds also exhibit slow waves similar to those observed during natural SWS. For these reasons, slow waves occurring under general anesthesia are commonly used in the investigation of sleep-related neurophysiology. However, how spectral properties of slow waves induced by anesthesia correspond to those occurring during natural SWS in birds has yet to be investigated systematically. In this study, we systematically analyzed spectral properties of electroencephalographic (EEG) patterns of pigeons (Columba livia) occurring under two commonly used anesthetics, isoflurane and urethane. These data were compared with EEG patterns during natural sleep. Slow waves occurring during spontaneous SWS, and those induced with isoflurane and urethane all showed greatest absolute power in the slowest frequencies (