Predictors of psychological stress and behavioural diversity among captive red panda in Indian zoos and their implications for global captive management.

At high elevations, biodiversity is at elevated risk from extinctions due to rapid environmental changes. In the most of its range in Himalayas, the red panda, an endangered species, is struggling to survive in the wild, and a global captive breeding programme has been launched to conserve the species. Because captivity can have negative impacts on animals, reducing the chance of successful reintroduction, we investigated the predictors of stereotyped behaviour and behavioural diversity of red panda (n = 26), and the effect of stereotypy on their behavioural diversity in three Indian zoos. Multivariate analysis showed that stereotypy increased with density of logs on the ground, age and higher among pandas in zoo 3 compared to zoo 2, but decreased with number of nests, sociality, tree density and tree height used. Similarly, behavioural diversity increased with log density, but decreased among pandas in zoo 2 compared to zoo 1, during summer compared to winter, and also with ambient temperature, stereotypy, tree density, and tree height used. The relationship between stereotypy and behavioural diversity was negative, but not significant. Provision of a greater density of trees was associated with higher levels of daytime inactivity. Findings from this study have global relevance, as the captive red panda experiences similar welfare issues around the world, and our data provide empirical support for some existing guidelines for red panda husbandry.

Location as a feature in pigeons' recognition of visual objects.

A number of different phenomena in pigeon visual cognition suggest that pigeons do not immediately recognize two identical objects in different locations as being "the same." To examine this question directly, pigeons were trained in an absolute go/no-go discrimination between arbitrary selections from sets of 16 images of paintings by Claude Monet. Of the eight positive stimuli, four always appeared in the same location, whereas the other four appeared equally often in each of two locations; the same was true of the negative stimuli. There was a consistent tendency for stimuli that appeared in a single position to be better discriminated than those that appeared in two positions, although by the end of training this effect was confined to negative stimuli. This result suggests that, for a pigeon, an image's location is one of the bundle of features that define it, and that pigeons need to learn to abstract from that feature rather than doing so automatically. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Suppression, resolve, and habit in everyday financial behaviour.

Everyday financial behaviour involves inter-temporal choices, between saving, spending, and debt. Consumers do not always take these decisions to their best advantage. Ainslie's analysis of the means to willpower as suppression, resolve, and habit is potentially applicable to understanding and improving the decisions that consumers make. Some relevant research on these topics exists, and it is briefly reviewed here.

Behavioral flexibility: A review, a model, and some exploratory tests.

This paper aimed to explore and clarify the concept of behavioral flexibility. A selective literature review explored how the concept of behavioral flexibility has been used in ways that range from acknowledging the fact that animals' behavior is not always bounded by instinctual constraints, to describing the variation between species in their capacity for innovative foraging, a capacity that has repeatedly been linked to having a brain larger than would be predicted from body size. This wide range of usages of a single term has led to some conceptual confusion. We sought to find a more precise meaning for behavioral flexibility by representing it within a simple formal model of problem solving. The key to our model is to distinguish between an animal's state of knowledge about the world and its observable behavior, using a construct of response strength to represent that underlying knowledge. We modelled behavioral flexibility as a parameter in the function that transforms response strengths into observable response probabilities. We tested this model in simulations based on some recent experimental work on animal problem solving. Initial results showed that parametric manipulation can mimic some of the behavioral effects that have been attributed to flexibility.

Measuring response inhibition with a continuous inhibitory-control task.

Inhibitory control enables subjects to quickly react to unexpected changes in external demands. In humans, this kind of behavioral flexibility is often used as an indicator of an individual's executive functions, and more and more research has emerged to investigate this link in nonhuman animals as well. Here we explored the value of a recently developed continuous inhibitory-control task in assessing inhibitory-control capacities in animals. Pigeons completed a response-inhibition task that required them to adjust their movement in space in pursuit of a reward across changing target locations. Inhibition was measured in terms of movement trajectory (path taken toward the correct location for trials in which the target location did and did not change) and velocity (both before and after correcting the trajectory toward the changed location). Although the observed velocities did not follow any of our predictions in a clear way, the pigeons' movement trajectories did prove to be a good indicator of inhibitory control, showing that pigeons, though limited in their capacities relative to the sophisticated control strategies expressed by humans, are capable of exerting some forms of inhibitory control. These results strengthen the role of this paradigm as a valuable tool for evaluating inhibitory-control abilities across the animal kingdom.

Pigeons' performance in a tracking change-signal procedure is consistent with the independent horse-race model.

In many cognitive tasks where humans are thought to rely on executive functioning, pigeons' behavior can be explained by associative processes. A key form of executive functioning is inhibiting prepotent responses, often investigated in humans by means of "Stop-Signal" or "Change-Signal" procedures. In these procedures, execution of a well-practiced ("Go") response to a stimulus is occasionally interrupted by a signal to withhold or alter the practiced response. Performance in such tasks is usually described by the "independent horse horse-race model." This model assumes that the processes that cause the Go and inhibitory responses occur independently; the process that finishes first determines the response observed. We further tested this model by training pigeons to track the circular movement of a colored patch around a touchscreen by pecking it; the spot occasionally deviated from its normal path (the Change signal). The pigeons had to inhibit the habitual movement of their heads to land a peck on the spot in its unexpected position. The key predictions of the independent horse-race model were confirmed in the pigeons' latency data. Thus, the independent race model can also successfully describe Stop-change performance of subjects that do not rely on executive control. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Inhibitory control and memory in the search process for a modified problem in grey squirrels, Sciurus carolinensis.

Inhibiting learned behaviours when they become unproductive and searching for an alternative solution to solve a familiar but different problem are two indicators of flexibility in problem solving. A wide range of animals show these tendencies spontaneously, but what kind of search process is at play behind their problem-solving success? Here, we investigated how Eastern grey squirrels, Sciurus carolinensis, solved a modified mechanical problem that required them to abandon their preferred and learned solution and search for alternative solutions to retrieve out-of-reach food rewards. Squirrels could solve the problem by engaging in either an exhaustive search (i.e., using trial-and-error to access the reward) or a 'backup' solution search (i.e., recalling a previously successful but non-preferred solution). We found that all squirrels successfully solved the modified problem on their first trial and showed solving durations comparable to their last experience of using their preferred solution. Their success and high efficiency could be explained by their high level of inhibitory control as the squirrels did not persistently emit the learned and preferred, but now ineffective, pushing behaviour. Although the squirrels had minimal experience in using the alternative (non-preferred) successful solution, they used it directly or after one or two failed attempts to achieve success. Thus, the squirrels were using the 'backup' solution search process. Such a process is likely a form of generalisation which involves retrieving related information of an experienced problem and applying previous successful experience during problem solving. Overall, our results provide information regarding the search process underlying the flexibility observable in problem-solving success.

In what sense are dogs special? Canine cognition in comparative context.

The great increase in the study of dog cognition in the current century has yielded insights into canine cognition in a variety of domains. In this review, we seek to place our enhanced understanding of canine cognition into context. We argue that in order to assess dog cognition, we need to regard dogs from three different perspectives: phylogenetically, as carnivoran and specifically a canid; ecologically, as social, cursorial hunters; and anthropogenically, as a domestic animal. A principled understanding of canine cognition should therefore involve comparing dogs' cognition with that of other carnivorans, other social hunters, and other domestic animals. This paper contrasts dog cognition with what is known about cognition in species that fit into these three categories, with a particular emphasis on wolves, cats, spotted hyenas, chimpanzees, dolphins, horses, and pigeons. We cover sensory cognition, physical cognition, spatial cognition, social cognition, and self-awareness. Although the comparisons are incomplete, because of the limited range of studies of some of the other relevant species, we conclude that dog cognition is influenced by the membership of all three of these groups, and taking all three groups into account, dog cognition does not look exceptional.

Multiple feature use in pigeons' category discrimination: The influence of stimulus set structure and the salience of stimulus differences.

Two experiments investigated what makes it more likely that pigeons' behavior will come under the control of multiple relevant visual stimulus dimensions. Experiment 1 investigated the effect of stimulus set structure, using a conditional discrimination between circles that differed in both hue and diameter. Two training conditions differed in whether hue and diameter were correlated in the same way within positive and negative stimulus sets as between sets. Transfer tests showed that all pigeons came under the control of both dimensions, regardless of stimulus set structure. Experiment 2 investigated the effect of the relative salience of the stimulus differences on three visual dimensions. Pigeons learned a multiple simultaneous discrimination between circular patches of sinusoidal gratings that differed in hue, orientation, and spatial frequency. In initial training, each stimulus only included one positive or negative feature, and the stimulus differences on the three dimensions were adjusted so that the rates of learning about the three dimensions were kept approximately equal. Transfer tests showed that all three dimensions acquired control over behavior, with no single dimension dominating consistently across pigeons. Subsequently the pigeons were trained in a polymorphous category discrimination using all three dimensions, and the level of control by the three dimensions tended to become more equal as polymorphous training continued. We conclude that the salience of the stimulus differences on different dimensions is an important factor in whether pigeons will come under the control of multiple dimensions of visual stimuli. (PsycINFO Database Record

Pigeons in control of their actions: Learning and performance in stop-signal and change-signal tasks.

In human participants, 2 paradigms commonly assumed to measure the executive-control processes involved in response inhibition are the stop-signal and change-signal tasks. There is, however, also considerable evidence that performance in these tasks can be mediated by associative processes. To assess which components of inhibitory response control might be associative, we developed analogues of these tasks for pigeons. We trained pigeons to peck quickly at 1 of 2 keys of different colors to obtain a food reward. On some trials, the rewarded key was replaced (after a varying interval) by a signal of a different color. For some birds, this was a change signal: pecking the signal had no effect, but pecking the usually unrewarded alternative key led to a reward, so the response had to be changed. For other birds, the change in color was a stop signal: pecking the alternative key remained ineffective, but pecking the signal now led to a timeout instead of the usual reward, so responses had to be withheld. Pigeons succeeded in both tasks, but performance declined with increasing signal delay. The details of performance in both tasks were consistent with the independent horse-race model of inhibitory control often applied to studies of human participants. This outcome further suggests that stop-signal tasks of the kind used here might not necessarily be suitable for assessing top-down executive-control processes in humans. (PsycINFO Database Record

How to stay perfect: the role of memory and behavioural traits in an experienced problem and a similar problem.

When animals encounter a task they have solved previously, or the same problem appears in a different apparatus, how does memory, alongside behavioural traits such as persistence, selectivity and flexibility, enhance problem-solving efficiency? We examined this question by first presenting grey squirrels with a puzzle 22 months after their last experience of it (the recall task). Squirrels were then given the same problem presented in a physically different apparatus (the generalisation task) to test whether they would apply the previously learnt tactics to solve the same problem but in a different apparatus. The mean latency to success in the first trial of the recall task was significantly different from the first exposure but not different from the last exposure of the original task, showing retention of the task. A neophobia test in the generalisation task suggested squirrels perceived the different apparatus as a different problem, but they quickly came to apply the same effective tactics as before to solve the task. Greater selectivity (the proportion of effective behaviours) and flexibility (the rate of switching between tactics) both enhanced efficiency in the recall task, but only selectivity enhanced efficiency in the generalisation task. These results support the interaction between memory and behavioural traits in problem-solving, in particular memory of task-specific tactics that could enhance efficiency. Squirrels remembered and emitted task-effective tactics more than ineffective tactics. As a result, they consistently changed from ineffective to effective behaviours after failed attempts at problem-solving.

Touch screen assays of behavioural flexibility and error characteristics in Eastern grey squirrels (Sciurus carolinensis).

Behavioural flexibility allows animals to adjust their behaviours according to changing environmental demands. Such flexibility is frequently assessed by the discrimination-reversal learning task. We examined grey squirrels' behavioural flexibility, using a simultaneous colour discrimination-reversal learning task on a touch screen. Squirrels were trained to select their non-preferred colour in the discrimination phase, and their preferred colour was rewarded in a subsequent reversal phase. We used error rates to divide learning in each phase into three stages (perseveration, chance level and 'learned') and examined response inhibition and head-switching during each stage. We found consistent behavioural patterns were associated with each learning stage: in the perseveration stage, at the beginning of each training phase, squirrels showed comparable response latencies to correct and incorrect stimuli, along with a low level of head-switching. They quickly overcame perseveration, typically in one to three training blocks. In the chance-level stage, response latencies to both stimuli were low, but during initial discrimination squirrels showed more head-switches than in the previous stage. This suggests that squirrels were learning the current reward contingency by responding rapidly to a stimulus, but with increased attention to both stimuli. In the learned stage, response latencies to the correct stimulus and the number of head-switches were at their highest, whereas incorrect response latencies were at their lowest, and differed significantly from correct response latencies. These results suggest increased response inhibition and attention allowed the squirrels to minimise errors. They also suggest that errors in the 'learned' stage were related to impulsive emission of the pre-potent or previously learned responses.

Disentangling learning from knowing: Does associative learning ability underlie performances on cognitive test batteries?

Are the mechanisms underlying variations in the performance of animals on cognitive test batteries analogous to those of humans? Differences might result from procedural inconsistencies in test battery design, but also from differences in how animals and humans solve cognitive problems. We suggest differentiating associative-based (learning) from rule-based (knowing) tasks to further our understanding of cognitive evolution across species.

Task-switching in pigeons: Associative learning or executive control?

Human performance in task-switching paradigms is seen as a hallmark of executive-control processes: switching between tasks induces switch costs (such that performance when changing from Task A to Task B is worse than on trials where the task repeats), which is generally attributed to executive control suppressing one task-set and activating the other. However, even in cases where task-sets are not employed, as well as in computational modeling of task switching, switch costs can still be found. This observation has led to the hypothesis that associative-learning processes might be responsible for all or part of the switch costs in task-switching paradigms. To test which cognitive processes contribute to the presence of task-switch costs, pigeons performed two different tasks on the same set of stimuli in rapid alternation. The pigeons showed no sign of switch costs, even though performance on Trial N was influenced by Trial N - 1, showing that they were sensitive to sequential effects. Using Pearce's (1987) model for stimulus generalization, we conclude that they learned the task associatively-in particular, a form of Pavlovian-conditioned approach was involved-and that this was responsible for the lack of any detectable switch costs. Pearce's model also allows us to make interferences about the common occurrence of switch costs in the absence of task-sets in human participants and in computational models, in that they are likely due to instrumental learning and the establishment of an equivalence between cues signaling the same task.

A stimulus-location effect in contingency-governed, but not rule-based, discrimination learning.

We tested pigeons' acquisition of a conditional discrimination task between colored grating stimuli that included choosing 1 of 2 response keys, which either appeared as white keys to the left and right of the discriminative stimulus, or were replicas of the stimulus. Pigeons failed to acquire the discrimination when the response keys were white disks but succeeded when directly responding to a replica of the stimulus. These results highlight how conditioning processes shape learning in pigeons: The results can be accounted for by supposing that, when pigeons were allowed to respond directly toward the stimulus, learning was guided by classical conditioning, but that responding to white keys demanded instrumental learning, which impaired task acquisition for pigeons. In contrast, humans completing the same paradigm showed no differential learning success depending on whether figure or position indicated the correct key. However, only participants who could state the underlying discrimination rule acquired the task, which implies that human performance in this situation relied on the deduction and application of task rules instead of associative processes.

Serial reversal learning in gray squirrels: Learning efficiency as a function of learning and change of tactics.

Learning allows individuals to adapt their behaviors flexibly to a changing environment. When the same change recurs repeatedly, acquiring relevant tactics may increase learning efficiency. We examined this relationship, along with the effects of proactive interference and other interference information, in a serial spatial reversal task with 5 gray squirrels (Sciurus carolinensis). Squirrels completed an acquisition and 11 reversal phases with a poke box in which 2 of 4 possible reward locations were baited diagonally in a square array. In this situation, an efficient tactic is to locate the diagonally related locations consecutively (integrative search tactic) instead of searching rewards in a clockwise or counterclockwise direction (sequential search tactic). All squirrels formed a learning set, acquiring successive reversals in fewer trials. Although 4 squirrels gradually employed more integrative tactics in locating the rewards both within and between phases, sequential tactics were used in the first trial of each phase. This suggests the integrative tactic did not depend on an association between the rewarded locations but was learned as a spatial pattern and/or by use of extra-apparatus cues to locate individual rewards. Generalized estimating equation models showed that learning efficiency increased with experience and tactic change. Although tactic change partially mediated the effect of learning on learning efficiency, learning remained an independent contribution to improved efficiency. Squirrels that used more integrative tactics made fewer total errors than squirrels that used less integrative tactics, suggesting that learning a task-relevant tactic using spatial cues can provide direct benefits in maximizing rewards and minimizing time costs.

Feature- versus rule-based generalization in rats, pigeons and humans.

Humans can spontaneously create rules that allow them to efficiently generalize what they have learned to novel situations. An enduring question is whether rule-based generalization is uniquely human or whether other animals can also abstract rules and apply them to novel situations. In recent years, there have been a number of high-profile claims that animals such as rats can learn rules. Most of those claims are quite weak because it is possible to demonstrate that simple associative systems (which do not learn rules) can account for the behavior in those tasks. Using a procedure that allows us to clearly distinguish feature-based from rule-based generalization (the Shanks-Darby procedure), we demonstrate that adult humans show rule-based generalization in this task, while generalization in rats and pigeons was based on featural overlap between stimuli. In brief, when learning that a stimulus made of two components ("AB") predicts a different outcome than its elements ("A" and "B"), people spontaneously abstract an opposites rule and apply it to new stimuli (e.g., knowing that "C" and "D" predict one outcome, they will predict that "CD" predicts the opposite outcome). Rats and pigeons show the reverse behavior-they generalize what they have learned, but on the basis of similarity (e.g., "CD" is similar to "C" and "D", so the same outcome is predicted for the compound stimulus as for the components). Genuinely rule-based behavior is observed in humans, but not in rats and pigeons, in the current procedure.

Behavioural responses of Eastern grey squirrels, Sciurus carolinensis, to cues of risk while foraging.

Previous studies have shown that Eastern grey squirrels modify their behaviour while foraging to offset risks of social and predatory costs, but none have simultaneously compared whether such modifications are performed at a cost to foraging. The present study directly compares how grey squirrels respond to cues of these risks while foraging. We simulated social risk and predatory risk using acoustic playbacks of stimuli that grey squirrels might be exposed to at a foraging patch: calls of conspecifics, heterospecifics (competitor and non-competitor) and predators. We found that grey squirrels responded to predator, heterospecific competitor and conspecific playbacks by altering their foraging and vigilance behaviours. Foraging was most disrupted by increased vigilance when we played calls of predators. Squirrels' response to calls of heterospecific competitors did not differ from their response to conspecific calls, and they resumed foraging more quickly after both compared to predator calls: whereas they showed little response to calls of non-competitor heterospecifics and a white noise control. We conclude that squirrels respond differentially to calls made by conspecifics, heterospecific competitors and predators, with the most pronounced response being to calls of predators. We suggest that squirrels may view conspecific and corvid vocalisations as cues of potential conflict while foraging, necessitating increased vigilance.

Pigeons can learn to make visual category discriminations using either low or high spatial frequency information.

Pigeons were trained to discriminate photographs of cat faces from dog faces, using either high- or low-pass spatial frequency filtered stimuli. Each pigeon was trained with multiple exemplars of the categories, but only with either high-pass or low-pass filtered stimuli. Not all pigeons reached the discrimination criterion. Successful pigeons were exposed in probe trials to test stimuli: cat and dog faces that had been subjected to the opposite kind of filtering from their training stimuli; the unfiltered original stimuli from which their training stimuli had been derived; and new exemplars of the cat- and dog-face categories, with the same filtering as was used in training. There was no transfer of discrimination to the stimuli with the opposite filtering from those used in training. Discrimination transferred, with some decrement, to the original unfiltered stimuli and to new exemplars with the same type of filtering as used in training. These results provide further evidence that both high and low spatial frequency information can be sufficient for pigeons to make category discriminations, and that there is no clear advantage for high spatial frequency information. They also confirm that high-pass and low-pass spatial frequency filtering produce images that have effectively no information in common. This article is part of a Special Issue entitled: Tribute to Tom Zentall.