Behavioural testing to determine differences between coping styles in Grey parrots (Psittacus erithacus erithacus) with and without feather damaging behaviour

Effects of lighted incubation and foraging enrichment during rearing on individual fear behavior, corticosterone, and neuroplasticity in laying hen pullets

Environmental conditions during incubation and rearing can influence stress responsivity of laying hen pullets throughout their lifespan, and therefore have important implications for their welfare. In this study, a 12:12h green LED light-dark cycle during incubation and larvae provisioning as enrichment during rearing were tested as strategies to optimize early-life conditions and thereby decrease stress responsivity in ISA Brown laying hens. A combination of parameters was measured to indicate neuronal, physiological, and behavioral changes that may affect fear and stress. The proteins calbindin D28k (calbindin1), doublecortin (DCX), and neuronal nuclein protein (NeuN) were quantified after hatch as a proxy for brain plasticity. Plasma and feather corticosterone levels were measured after hatch and at the end of the rearing phase, and fearfulness was investigated through a series of behavioral tests (i.e., voluntary approach, open field, tonic immobility, and manual restraint tests). No effects of light during incubation were found on calbindin1, DCX, or NeuN. Neither of the treatments affected corticosterone levels in blood plasma and feathers. Light-incubated pullets showed less fearfulness towards humans in the voluntary approach test, but not in the other behavioral tests reported in this study. Larvae provisioning had no effect on behavior. Our study showed minor effects of light during incubation and no effects of enrichment during rearing on stress responsivity of laying hen pullets. The small effects may be explained by the enriched rearing conditions for all birds in this experiment (low stocking density, natural daylight, and 24/7 classical music). Given the promising results of lighted incubation in other studies, which were mostly performed in broiler chickens, and evidence regarding the positive effects of enrichment during rearing, the potential of these strategies to improve laying hen welfare needs to be explored further.

Personality Characteristics Predictive of Social Pairing Outcome in Orange-Winged Amazon Parrots (Amazona amazonica)

Most wild parrot species live in flocks, enriched by the environment and conspecific interactions. Captive parrots often live individually and are prone to behavioral maladaptation. If captive parrots and their behavior become intolerable, they are commonly relinquished to rescue organizations. This study aims to create parrot personality assessments for use by rescuers adding newly acquired parrots to shared environments. The study involved 20 orange-winged Amazon parrots (10 M, 10 F). Observers familiar with each bird scored its personality and analyses determined three sets of personalities: Social, Guarded, and Nervous Each parrot was paired with its 10 heterosexual counterparts and its interactions monitored remotely and captured on video. Pairing trials occurred over 72 hours in a specially designed pairing structure. Parrot personality could predict pairing success. Social-Guarded and Social-Nervous were more successfully paired, with individuals maintaining a close distance to one another and displaying increased rest-stretch behavior. Time of day influenced success with Social-Nervous pairs successful at all times of day, Social-Social pairs in the AM, and Guarded-Guarded pairs in the PM period. The study results suggest that rescues can use personality assessment and specific behaviors during cohabitation to predict OWA novel pairing outcomes.

Individual Responses of Captive Amazon Parrots to Routine Handling Can Reflect Their Temperament

Individual responses to physical restraint and temperament have been assessed in birds of several species; however, there is a paucity of research which investigates both aspects, especially in captive parrots. This lack of studies raises doubts about which temperament traits, if any, are evidenced during handling and if the intensity of responses to restraint is affected by behavioral training programs, a common practice used in ex situ conservation programs. To understand more about the subject, this study aimed to identify the main temperament dimensions of parrots and investigate their relationship with response to physical restraint for blood collection. A secondary aim was to evaluate whether parrots exhibited higher responsiveness to physical restraint after training to improve flight capacity and increase aversion to humans. The main dimensions identified were activity, neophilia, vigilance, and fearfulness. The more fearful parrots in temperament evaluations were more responsive to physical restraint, showing more vocalizations and struggle attempts than the less fearful ones. After training, the parrots showed higher responsiveness to physical restraint. We suggest that physical restraint for routine handling, such as blood collection, could be a feasible option for centers of rehabilitation to use to obtain data on individual behavioral differences in fear responses.

Temperament in Captivity, Environmental Enrichment, Flight Ability, and Response to Humans in an Endangered Parrot Species

Temperament assessment is useful in reintroduction programs. Reactivity to humans and flight ability are also important behavioral aspects for captive parrots candidates to reintroduction. The study aimed: a) to evaluate if behavioral responses to environmental enrichment differ as a function of temperament in captive Vinaceous-breasted Amazon parrots (Amazona vinacea) and b) to evaluate if the behavioral responses to environmental enrichment are related to flight ability and animal's reaction to human when offered food. A temperament assessment was performed and behavioral evaluations of parrots (n = 13) using an ethogram were carried out, in two phases: unenriched and enriched. Flight skill and food reward tests were also performed. Two temperament dimensions were described ("vigilance" and "risk-taking"). Parrots categorized as "vigilant" spent less time feeding on the feeder and interacting with environment. Animals with compromised flight ability spent more time preening, had lower frequency of vocalizations, tended to have fewer negative social interactions, and interacted less with the enrichment than individuals with better flight ability. Flight performance and temperament of captive parrots should be considered while planning and executing environmental enrichment techniques.

Non-Invasive Measurement of Adrenocortical Activity in Blue-Fronted Parrots (Amazona aestiva, Linnaeus, 1758)

Parrots kept in zoos and private households often develop psychological and behavioural disorders. Despite knowing that such disorders have a multifactorial aetiology and that chronic stress is involved, little is known about their development mainly due to a poor understanding of the parrots' physiology and the lack of validated methods to measure stress in these species. In birds, blood corticosterone concentrations provide information about adrenocortical activity. However, blood sampling techniques are difficult, highly invasive and inappropriate to investigate stressful situations and welfare conditions. Thus, a non-invasive method to measure steroid hormones is critically needed. Aiming to perform a physiological validation of a cortisone enzyme immunoassay (EIA) to measure glucocorticoid metabolites (GCM) in droppings of 24 Blue-fronted parrots (Amazona aestiva), two experiments were designed. During the experiments all droppings were collected at 3-h intervals. Initially, birds were sampled for 24 h (experiment 1) and one week later assigned to four different treatments (experiment 2): Control (undisturbed), Saline (0.2 mL of 0.9% NaCl IM), Dexamethasone (1 mg/kg IM) and Adrenocorticotropic hormone (ACTH; 25 IU IM). Treatments (always one week apart) were applied to all animals in a cross-over study design. A daily rhythm pattern in GCM excretion was detected but there were no sex differences (first experiment). Saline and dexamethasone treatments had no effect on GCM (not different from control concentrations). Following ACTH injection, GCM concentration increased about 13.1-fold (median) at the peak (after 3-9 h), and then dropped to pre-treatment concentrations. By a successful physiological validation, we demonstrated the suitability of the cortisone EIA to non-invasively monitor increased adrenocortical activity, and thus, stress in the Blue-fronted parrot. This method opens up new perspectives for investigating the connection between behavioural disorders and stress in this bird species, and could also help in their captive management.

The Relationship between Personality Dimensions and Resiliency to Environmental Stress in Orange-Winged Amazon Parrots (Amazona amazonica), as Indicated by the Development of Abnormal Behaviors

Parrots are popular companion animals, but are frequently relinquished because of behavioral problems, including abnormal repetitive behaviors like feather damaging behavior and stereotypy. In addition to contributing to pet relinquishment, these behaviors are important as potential indicators of diminished psychological well-being. While abnormal behaviors are common in captive animals, their presence and/or severity varies between animals of the same species that are experiencing the same environmental conditions. Personality differences could contribute to this observed individual variation, as they are known risk factors for stress sensitivity and affective disorders in humans. The goal of this study was to assess the relationship between personality and the development and severity of abnormal behaviors in captive-bred orange-winged Amazon parrots (Amazona amazonica). We monitored between-individual behavioral differences in enrichment-reared parrots of known personality types before, during, and after enrichment deprivation. We predicted that parrots with higher scores for neurotic-like personality traits would be more susceptible to enrichment deprivation and develop more abnormal behaviors. Our results partially supported this hypothesis, but also showed that distinct personality dimensions were related to different forms of abnormal behavior. While neuroticism-like traits were linked to feather damaging behavior, extraversion-like traits were negatively related to stereotypic behavior. More extraverted birds showed resiliency to environmental stress, developing fewer stereotypies during enrichment deprivation and showing lower levels of these behaviors following re-enrichment. Our data, together with the results of the few studies conducted on other species, suggest that, as in humans, certain personality types render individual animals more susceptible or resilient to environmental stress. Further, this susceptibility/resiliency can have a long-term effect on behavior, as evidenced by behavioral changes that persisted despite re-enrichment. Ours is the first study evaluating the relationship between personality dimensions, environment, and abnormal behaviors in an avian species.

Tail biting in pigs: blood serotonin and fearfulness as pieces of the puzzle?

Tail biting in pigs is a widespread problem in intensive pig farming. The tendency to develop this damaging behaviour has been suggested to relate to serotonergic functioning and personality characteristics of pigs. We investigated whether tail biting in pigs can be associated with blood serotonin and with their behavioural and physiological responses to novelty. Pigs (n = 480) were born in conventional farrowing pens and after weaning at four weeks of age they were either housed barren (B) or in straw-enriched (E) pens. Individual pigs were exposed to a back test and novel environment test before weaning, and after weaning to a novel object (i.e. bucket) test in an unfamiliar arena. A Principal Component Analysis on behaviours during the tests and salivary cortisol (novel object test only) revealed five factors for both housing systems, labeled ‘Early life exploration’, ‘Near bucket’, ‘Cortisol’, ‘Vocalizations & standing alert’, and ‘Back test activity’. Blood samples were taken at 8, 9 and 22 weeks of age to determine blood platelet serotonin. In different phases of life, pigs were classified as tail biter/non-tail biter based on tail biting behaviour, and as victim/non-victim based on tail wounds. A combination of both classifications resulted in four pig types: biters, victims, biter/victims, and neutrals. Generally, only in phases of life during which pigs were classified as tail biters, they seemed to have lower blood platelet serotonin storage and higher blood platelet uptake velocities. Victims also seemed to have lower blood serotonin storage. Additionally, in B housing, tail biters seemed to consistently have lower scores of the factor ‘Near bucket’, possibly indicating a higher fearfulness in tail biters. Further research is needed to elucidate the nature of the relationship between peripheral 5-HT, fearfulness and tail biting, and to develop successful strategies and interventions to prevent and reduce tail biting.