The effects of food limitation on behavior, corticosterone, and the use of social information in the red crossbill (Loxia curvirostra).

Meeting metabolic demands through foraging is a basic animal need that drives the evolution of foraging adaptations. The use of social information is one adaptation that could improve foraging success and fitness if it helps animals locate food when conditions are challenging. It is unknown if food limitation-or the glucocorticoid hormones that are often released when food is limited-can influence the extent to which animals use social information or their ability to learn novel foraging techniques. We explored the effects of limited access to food on activity levels, corticosterone secretion, and social information use in red crossbills, a highly social songbird species adapted to cope with high degrees of resource unpredictability. Using an observer/demonstrator paradigm, food limited or well fed observers were allowed to watch demonstrators solve a novel feeding puzzle before being allowed to attempt the puzzle themselves across repeated trials. Our findings suggest that food limitation transiently increased activity levels but did not result in long-term elevations of corticosterone and did not increase the speed at which red crossbills utilized social information to solve the novel foraging task. However, food limitation may have increased the value of using socially acquired information, as foraging technique performance improved faster in food limited birds relative to controls. Social learning was further demonstrated by the red crossbills in this study when naïve observers overwhelmingly learned a socially-demonstrated task over an undemonstrated task when tested on a two-task foraging board.

Performance on the Hamilton search task, and the influence of lateralization, in captive orange-winged Amazon parrots (Amazona amazonica).

Psittacines are generally considered to possess cognitive abilities comparable to those of primates. Most psittacine research has evaluated performance on standardized complex cognition tasks, but studies of basic cognitive processes are limited. We tested orange-winged Amazon parrots (Amazona amazonica) on a spatial foraging assessment, the Hamilton search task. This task is a standardized test used in human and non-human primate studies. It has multiple phases, which require trial and error learning, learning set breaking, and spatial memory. We investigated search strategies used to complete the task, cognitive flexibility, and long-term memory for the task. We also assessed the effects of individual strength of motor lateralization (foot preference) and sex on task performance. Almost all (92%) of the parrots acquired the task. All had significant foot preferences, with 69% preferring their left foot, and showed side preferences contralateral to their preferred limb during location selection. The parrots were able to alter their search strategies when reward contingencies changed, demonstrating cognitive flexibility. They were also able to remember the task over a 6-month period. Lateralization had a significant influence on learning set acquisition but no effect on cognitive flexibility. There were no sex differences. To our knowledge, this is the first cognitive study using this particular species and one of the few studies of cognitive abilities in any Neotropical parrot species.

Are Underweight Shelter Dogs More Likely to Display Food Aggression toward Humans?

It is commonly believed that underweight or emaciated dogs are predisposed to food aggression toward humans. Each year, the American Society for the Prevention of Cruelty to Animals (ASPCA) receives hundreds of dogs from criminal cruelty cases. The dogs range from emaciated to overweight. We analyzed existing data from 900 such dogs to examine the relationship between body condition score and food and chew item aggression toward humans. Across all types of cruelty cases, 9.2% of dogs were aggressive over the food, chew, or both, which is a lower prevalence than that previously reported among shelter dogs. Dogs from cruelty cases originating in New York City were more likely to show aggression over food (z = 3.91, p < 0.001) and chew items (z = 2.61, p = 0.01) than dogs from large-scale cruelty cases, although it is unclear why. Female dogs were less likely to show food (z = -3.75, p < 0.001) and chew item (z = -2.25, p = 0.02) aggression compared to males. Underweight dogs were not more likely to display food aggression, but when they did, the aggression was no more severe than that of normal-weight dogs (Fisher's exact tests = 0.41 and 0.15 for the Food Bowl and Chew Item scenarios, respectively). Breed type was not a significant predictor of aggression. Canine food aggression does not appear to be an aberrant behavior caused by a history of food scarcity but may be related to biological factors such as sex. These findings could prove useful for animal behavior subject matter experts testifying in court or consulting on cruelty cases, as they could speak with scientific validity to the question of whether there is a link between previous food scarcity and the likelihood of food aggression in dogs.

Psittacine cognition: Individual differences and sources of variation.

Both the number and breadth of avian cognition studies have expanded in the past three decades. Parrots have a long history as subjects in avian cognition research. This paper summarizes results from a number of parrot species tested on basic learning, and physical & social cognitive processes, with an emphasis on individual differences. Early psittacine studies were aimed at demonstrating a particular cognitive ability existed in a given species. Because of this proof of capacity focus, early studies typically included only a single individual or a dyad of parrots. Existing reviews of parrot cognition tend to focus on a particular cognitive component in a single species, or even a single individual. Despite the narrow focus, results from increasing sample sizes show intraspecific variation across a variety of cognitive assessments and parrot species. Intraspecific variability in performance on cognitive tasks highlights the need for establishing a cognitive normal range for a given species and process. To accomplish this, large numbers of individuals need to be tested and non-cognitive sources of variability need to be controlled. Once species typical cognitive normal ranges are established, cognitive comparisons can be made between parrot species and between parrots and other taxa.

Sleep disturbances in the rotenone animal model of Parkinson disease.

Parkinson disease (PD) is characterized by the degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNc) and the presence of intracytoplasmatic inclusions known as Lewy bodies. Chronic administration of rotenone (RT) produces Parkinson's-like symptoms in rats. Because PD patients have disrupted sleep patterns, we determined if chronic RT administration produces similar changes in rat sleep. RT was administered for 28 days to rats. Basal and vehicle (VH) rats received saline or dimethyl sulfoxide and polyethylene glycol (1:1), respectively. VH infusion induced a progressive decrease in non-rapid eye movement sleep (NREMS) during the 4-week period of VH infusion and REMS was reduced in the third and fourth week of VH infusion. VH infusion did not induce dopaminergic cell degeneration. Rats receiving RT infusion also showed decreased NREMS during the treatment. REMS was dramatically reduced on day 7 although subsequently on days 13 and 20 REMS was similar to basal values. After 4 weeks of RT infusion, time in REMS was decreased again. In RT-treated rats, progressive dopaminergic cell degeneration occurred in the SNc. After 4 weeks of daily injections of L-dopa in RT-infused rats, NREMS values remained similar to those values obtained after RT alone. L-dopa therapy did, however, induce a recovery of REMS in weeks 3 and 4 of RT infusion. Dopaminergic cell damage persisted in the L-dopa-RT-infused rats. We conclude that the RT-PD rat model is associated with large long-term sleep disruption, however, the vehicle, DMSO/PEG had as large an effect as RT on sleep, thus changes in sleep cannot be ascribed to loss of dopaminergic cells. Such results question the validity of the RT-PD rat model.

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.

Viewpoint of animal welfare organisations on the long distance transportation of farm animals.

The World Society for the Protection of Animals (WSPA) describes the viewpoint of non-governmental organisations (NGOs) involved in the welfare of farm animals undergoing long distance transportation. The guiding principle is that the potential for poor animal welfare increases with the distance and duration of travel. Thus, farm animals should be slaughtered as close to their farm of origin as possible and trade in live animals for slaughter should be replaced with a trade in meat only. The challenge for reform in long distance transportation of animals is to raise community awareness about the issue without invoking the psychological phenomenon of cognitive dissonance, which has the paradoxical effect of reinforcing adverse behaviour. NGO activity in long distance transportation of animals is described for Australia, the United States and the European Union and aspirations elsewhere in the world are discussed. Importantly, animal welfare NGOs are now recognised by and have a voice in the forums of international bodies such as the World Organisation for Animal Health (Office International des Epizooties: OIE) and the International Finance Corporation. Challenges for the future include the development of partnerships in global markets to replace the trade in live animals with a meat-only trade.