Dr Andrea Griffin

The ability to gain information from one situation, acquire new skills and/or perfect existing ones, and subsequently apply them to a new situation is a key element in behavioural flexibility and a hallmark of innovation. A flexible agent is expected to store these skills and apply them to contexts different from that in which learning occurred. Goffin's cockatoos (Cacatua goffiniana) are highly innovative parrots renowned for their problem-solving and tool-using skills and are thus excellent candidates to study this phenomenon. We hypothesized that birds allowed to use a tool in a larger variety of contingencies would acquire a broader expertise in handling it, facilitating its transfer to new tasks. In our study, we compared the performance of two groups of captive Goffin's cockatoos (N¿=¿13): A test group received more diverse learning and motor experiences on multiple applications of a hook-type tool, while a control group received intensive, total trial-matched, experience with a single application of the same tool. Then, both groups were tested on two novel tasks to determine whether experience with the tool in multiple contexts would facilitate performance during transfer. While both groups transferred to both novel tasks, group differences in performance were apparent, particularly in the second transfer task, where test birds achieved a higher success rate and reached criteria within fewer trials than control birds. These results provide support for the prediction that experiencing a diverse range of contingencies with a tool appears to allow birds to acquire generalizable knowledge and transferrable skills to tackle an untrained problem more efficiently. In contrast, intensive experience with the tool in a single context might have made control birds less flexible and more fixated on previously learned tool-dependent instances.

Biodiversity monitoring is crucial for effective conservation efforts. Effective monitoring allows managers to determine the status and trends of biodiversity, as well as the success of conservation actions. The population of the Broad-toothed Rats (Mastacomys fuscus) in the Barrington Tops National Park New South Wales, Australia has been monitored since 1999 via scat and live-trapping surveys. We reviewed the methods used and analysed the data produced with the aim of describing patterns of population change over time using a range of outcome variables and identifying different climate correlates. A secondary aim was to explore the use of population statistics that account for imperfect detection by comparing naïve occupancy, with an index of relative abundance based on trap effort, the latency to find scats during scat surveys and an occupancy model based on trapping surveys. Neither of these three methods accounts for detectability variation. Naïve occupancy decreased slightly over time, while the relative abundance based on trap effort revealed no evidence of change. Additionally, naïve occupancy decreased with increasing temperature while temperature had no clear impact on relative abundance. Finally, precipitation had no impact on either naïve occupancy or relative abundance. We found no evidence of a relationship between the latency to find scats and the index of relative abundance, suggesting that one or neither is related to actual abundance. Finally, a multi-season occupancy model found occupancy probability to be 0.78 ± 0.23 (standard error); detection probability as 0.51 ± 0.06; seasonal colonisation rate as 0.36 ± 0.13 and seasonal extinction rate at 0.44 ± 0.13. We conclude that despite significant investment in monitoring, this historical data set does not allow managers to ascertain whether population change has occurred and to identify potential drivers of change. Careful consideration of future methods, in particular, whether there is imperfect detection in scat surveys, will help to inform future monitoring.

Humans prey on animals with often dramatic effects on abundances, but also alterations to the phenotypical composition of prey populations. Instances of lethal management provide an opportunity to explore proximate mechanisms of phenotypical change. While there is evidence from exploitative predation (e.g. fisheries) that prey can change via evolutionary mechanisms, we present one of the first studies to explore this effect in an invasive vertebrate species that is being lethally controlled. Using an avian species that is known to be changing its behaviour in areas where it is heavily trapped, this study explored whether trapping of specific behavioural phenotypes might underpin observed changes. The behaviour of common mynas, Acridotheres tristis, captured using a large walk-in baited trap was compared with that of mynas captured using a cryptic whoosh net. All tests revealed significant inter-individual variation in ecologically meaningful aspects of myna temperament. Contrary to our predictions, however, we found no evidence that mynas captured in traps were more exploratory, more sociable, less fearful or better problem-solvers than those captured with the cryptic net. We present various interpretations of this finding, including the possibility learning might underpin behavioural changes in free-ranging mynas from heavily trapped populations, complemented by some selection against sociability and low fearfulness. As such, our findings and their interpretation will serve to guide future research on prey responses to human predation and inform animal management practices.

Humans are translocating species beyond their native ranges increasingly fast. These translocations create a natural experiment to explore the role of cognition in invasiveness. Alien vertebrate species face many behavioral challenges upon introduction to novel environments. But here, we focus on how alien species might use cognition to find and adopt new foods. Cognitive processes are particularly well suited to this challenge, a prediction supported by large-scale comparative analyses of alien species¿ historical introductions. Here, we parse the steps involved in approaching, handling, tasting, and evaluating novel food sources and, for each one, describe which cognitive abilities are the most relevant. In bringing attention to the functional importance of innovative feeding both conceptually and empirically, synthesizing the cognitive processes involved, highlighting the current void of knowledge, and arguing that alien species are particularly well suited to controlled experimental cognitive studies, this piece scaffolds future experimental cognitive research.

Conservation managers cannot manage what they don't know about, yet our existing biodiversity monitoring is idiosyncratic and small in scale. One of Australia's commitments to the Convention for Biological Diversity in 2015 was the creation of a national biodiversity monitoring programme. This has not yet occurred despite the urgent need to monitor common and threatened species, as highlighted by the challenges of determining the biodiversity impacts of the Black Summer fires of 2019/20. In light of improvements to automation, miniaturisation and powering devices, the world urgently needs to scale-up biodiversity monitoring to become coordinated, comprehensive and continuous across large scales. We propose the BIOMON project that could achieve this where individual sensor nodes use machine learning models to identify biodiversity via sound or photos onboard. This could be coupled with abiotic data on temperature and humidity, plus factors such as bushfire smoke. Nodes would be set within networks that transmit the results back to a central cloud repository where robust analyses are conducted and provided free to the public (along with the raw data). Network arrays could be set up across entire continents to measure the change in biodiversity. No one has achieved this yet, and significant challenges remain associated with training the algorithms, low power cellular network coverage, sensor power versus memory trade-offs, and sensor network placement. Much work is still needed to achieve these goals; however we are living in the 21st Century and such lofty goals cannot be achieved unless we start working towards them.

The current study represents the first attempt to analyse quantitatively, within a phylogenetic framework, uptake and partitioning patterns of copper (Cu), zinc (Zn), cadmium (Cd) and lead (Pb) in extant saltmarsh taxa globally, and to assess associations of these patterns with various plant traits indicative of their halophytic adaptations. Despite saltmarsh being diverse taxonomically, most saltmarsh taxa accumulate metals to roots at, or above, unity (> 1). Further, there is significant translocation from roots to shoot for Cu, Zn and Cd (= 1), however, Pb is less mobile (TF = 0.65). Patterns of accumulation were similar among families, except greater Cd accumulation to roots in members of Juncaceae. Patterns of uptake to roots and translocation to leaves were broadly similar among plant type, plant form, habitat and photosynthetic mode. Zinc is lower in the leaves of salt-secreting species for some closely related taxa, suggesting some species co-excrete sodium (Na+) and Zn2+ through glands in leaf tissue. Salinity tolerance has no relationship to metal uptake and translocation. Translocation of Zn is greater at lower Zn sediment exposures, reflecting its active uptake and essentiality, but such bias does not affect outcomes of analyses when included as a covariate.

Theory suggests that overcrowding and increased competition in urban environments might be detrimental to individual condition in avian populations. Unfavourable living conditions could be compounded by changes in dietary niche with additional consequences for individual quality of urban birds. We analysed the isotopic signatures, signal coloration, body condition, parasitic loads (feather mites and coccidia), and immune responsiveness of 191 adult common (Indian) mynas (Acridotheres tristis) captured in 19 localities with differing levels of urbanization. The isotopic signature of myna feathers differed across low and high urbanized habitats, with a reduced isotopic niche breadth found in highly urbanized birds. This suggests that birds in high urban environments may occupy a smaller foraging niche to the one of less urbanized birds. In addition, higher degrees of urbanization were associated with a decrease in carotenoid-based coloration, higher ectoparasite loads and higher immune responsiveness. This pattern of results suggests that the health status of mynas from more urbanized environments was poorer than mynas from less modified habitats. Our findings are consistent with the theory that large proportions of individual birds that would otherwise die under natural conditions survive due to prevailing top-down and bottom-up ecological processes in cities. Detrimental urban ecological conditions and search for more favourable, less crowded habitats offers the first reasonable explanation for why an ecological invader like the common myna continues to spread within its global invasive range.

Australian cavity-nesting birds in urban habitats can encounter strong competition for nesting cavities. This results from the shortage of old large hollow-bearing trees in urban areas and because cities often host a suite of alien birds, including cavity-nesters. However, it is unclear whether some behavioural differences are involved with access to nesting cavities. We aimed to examine parental nest attendance, nest disturbance and breeding success in native parrots and the most common invasive urban bird in Australia, the Common Myna, Acridotheres tristis. We installed 78 experimental nest boxes in Newcastle, the second largest city in New South Wales, Australia, to compare native parrots and Mynas. We found that despite occupying nest boxes equally, native parrots had significantly lower breeding success, lost more clutches to hatch failure, exhibited lower levels of parental nest attendance, and encountered higher levels of nest disturbance than the alien Myna. These findings provide important insight into the breeding success of native and alien secondary cavity-nesting birds in cities. Evaluating the effectiveness of urban nest boxes will help guide future research and management aimed at optimising nest box design for maintaining native cavity breeders.

The extent to which native species utilize urban environments depends on species responses to multiple threatening processes. Here, we aimed to quantify changes in bird communities in response to changing habitat structure, invasive species and aggressive native species. We conducted surveys in two independently invaded regions with similar patterns of urban development. The study regions were New South Wales (NSW) and Queensland (QLD), Australia. We observed 127 species in NSW and 144 species in QLD. Most species (NSW 83 and QLD 84) are urban adapters making use of some or all urban sub-environments. Urban avoiders, species only found in remnant vegetation, were the second largest group (urban avoiders: NSW 23 and QLD 31). We found the lowest richness in the most urban sites (urban exploiters: NSW 10 and QLD 15). Using generalized linear mixed models, we found a non-significant relationship between species richness and the abundance of aggressive species like the common myna and noisy miners, Manorina melanocephala, but a significant positive correlation with the percentage of shrub cover at a site. As there is a gradual loss of species with increasing urbanization, retaining higher complexity in vegetation structure in urban areas will support large numbers of species and could help mitigate the potential impacts of aggressive urban-adapted species and habitat loss.

We examined the patterns of uptake and partitioning of metal(loid)s in Suaeda australis from three highly urbanised estuaries (Sydney Olympic Park, Hunter Wetlands and Lake Macquarie) in NSW, Australia. Of these, Sydney Olympic Park was found to be the most contaminated estuary in terms of combined sediment metal(loid) load, followed by Hunter Wetlands and lowest in Lake Macquarie (via PERMANOVA). Uptake in roots was greater for the essential metals Cu and Zn along with the non-essential metal Cd and the metalloid Se (root BCFs >1) and lower for Pb and As (root BCFs <1). Substantial barriers for translocation from roots to stems were identified for all metal(loid)s (stem TFs; 0.07¿0.68). Conversely, unrestricted flow from stems to leaves was observed for all metal(loid)s at unity or higher (leaf TFs = 1). Strong linear relationships between sediment and root for Zn and Pb were observed, indicating roots as a useful bioindicator.

Interaction networks among native and invasive species in a community can inform both invasion impacts and applied management of invasive species. The intensity of aggressive interactions may be related to the overlap in species¿ ecological niche and functional traits, especially in cavity-breeding species, that often compete for limited nesting sites. Australia is home to over 100 native and introduced cavity-nesting species, including several invasive species that are widespread globally, such as the common myna Acridotheres tristis. Here, we aimed to test the extent to which shared functional traits inform the intensity of aggression between cavity-nesting birds. We quantified the outcomes of aggressive interactions between birds in large hollow-bearing trees in SE Queensland, Australia. We examined whether more similarly sized birds interacted more frequently, whether larger species won aggressive interactions more often, and whether cavity-breeding species with similar preferences for nesting sites (breeding-niche space) interacted more frequently. We recorded a total of 410 aggressive interactions and 48 interacting bird species around tree hollows, including 20 cavity-nesting bird species. These interactions were dominated by the invasive common myna, the native noisy miner (a non-cavity-breeder) and the native rainbow lorikeet Trichoglossus moluccanus, but the common myna won the largest total number of interspecific interactions. On average, larger birds won aggressive interactions more frequently, yet there were some important exceptions to this finding; the common myna (113¿±¿30¿g) won 26 of the 29 interactions against the larger native rainbow lorikeet (126¿±¿44¿g). Importantly, species with more similar nest-site preferences were observed aggressively interacting more frequently. Synthesis and applications. The impact of the invasive common myna was higher-site preferences. Control efforts for the myna should focus on birds that nest in natural tree hollows. An analysis of shared traits by managers could be used to help identify how many local species would benefit from common myna control in a given area and test if further behavioural studies of common myna are warranted.

Conspicuous coloured displays from ultraviolet to bright red have been documented in many species throughout the animal kingdom. These colours often occur as sexual signals and can be incorporated into different types of integuments (e.g. scales, feathers, skin). Two main mechanisms are known to produce coloured integuments: pigmentation and tissue structure. Although pigmental and structural coloration are separate mechanisms and can occur independently, some coloured displays might emerge from a combination of both. Here, we demonstrate, using biochemical, optical and morphological methodologies, that the yellow coloration of the skin located around the eye of Common (Indian) Mynas (Acridotheres tristis) is produced by both light-reflecting nanostructures and light-absorbing carotenoid pigments. Our analysis confirms that nanostructured collagen in the avian dermis work in combination with carotenoid pigments to produce vivid integumentary colours. Identifying the mechanisms behind the production of a coloured signal provides a basis for predicting how a signal¿s function might be influenced by environmental factors such as fledgling nutrition.

Inference by exclusion is the ability to select a given option by excluding the others. When designed appropriately, tests of this ability can reveal choices that cannot be explained by associative processes. Over the past decade, exclusion reasoning has been explored in several non-human taxonomic groups, including birds, mainly in Corvids and Parrots. To increase our understanding of the taxonomic distribution of exclusion reasoning and, therefore, its evolution, we investigated exclusion performances in red-tailed black cockatoos (Calyptorhynchus banksii), an Australian relative of the Goffin cockatoo (Cacatua goffini), using a food-finding task. Cockatoos were required to find a food item hidden in 1 of the 2 experimenter's hands. Following training sessions in which they reliably selected the closed baited hand they had just been shown open, each individual was tested on 4 different conditions. Critical to demonstrating exclusion reasoning was the condition in which they were shown the empty hand and then offered a choice of both closed hands. The performance of all birds was above chance on all experimental conditions but not on an olfactory and/or cuing control condition. The results suggest that the birds might be able to infer by exclusion, although an explanation based on rule learning cannot be excluded. This first experiment in red-tailed black cockatoo highlights the potential of this species as a model to study avian cognition and paves the pathway for future investigations.

Social learning of novel threats coupled with adaptive generalization from learned to novel cues together provide the cognitive mechanisms by which adaptive avoidance of threats can spread rapidly both within and across generations. Whereas attention to effects of fishing and hunting on prey is increasing, nothing is known about how human predation can alter the behavior of invasive animals. Here, we examined whether common (Indian) mynas, Acridotheres tristis, one of the most widespread invasive birds in Australia and invasive to many other parts of the world, are learning to respond to anthropogenic predation. We analyzed behavior at an experimental food patch provisioned by 2 distinctly clothed persons both before and after mynas had observed one of the 2 persons seemingly capture conspecifics inside a trap placed at the food patch. After the demonstration, mynas landed in smaller numbers at the food patch and took longer to land. Further, mynas alarm called more when provisioned by the person who had been involved in trapping. Future work will determine whether narrow generalization gradients are a consistent feature of synanthropic species or whether they broaden as a function of human predation threat level as is predicted by the Predator Recognition Continuum Hypothesis. Practical implications for control are discussed.

Bird damage to commercial crops is a significant problem across the globe, especially for high value crops like wine grapes. Various bird control methods have been developed in the past to reduce bird damage. After a brief review of the current bird damage control strategies, we found the most effective methods, such as netting and hiring a human scarer, rely on intensive manual labour, as well as fragile and costly infrastructure. Whereas the cheaper methods, such as using alarm calls and predator models, are effective for no more than two weeks before the birds habituate to them. We are proposing a novel Unmanned Aerial Vehicle (UAV, more commonly referred to as drone) system incorporating bird psychology for efficient bird damage control. The UAV is equipped with a loud speaker broadcasting distress calls, as well as a crow taxidermy installed on the undercarriage that appears as captured prey. This special UAV configuration is designed to engage birds¿ well-established abilities to learn to recognise and avoid novel predators, thus providing the benefit that a long-term fear response towards the UAV can be expected. The initial trials were carried out in vineyards around south-eastern Australia. Results indicated the UAV can deter large pest birds such as ravens and cockatoos in a 50-m radius centred on the UAV for an extended period of time. The UAV can also effectively deter small pest birds such as silvereyes for brief time periods after exposure to the UAV. It is also evident from the results that while one UAV is sufficient to protect vineyards smaller than 25 ha, multiple UAVs are needed to protect a large vineyard effectively.

Compassionate conservation focuses on 4 tenets: first, do no harm; individuals matter; inclusivity of individual animals; and peaceful coexistence between humans and animals. Recently, compassionate conservation has been promoted as an alternative to conventional conservation philosophy. We believe examples presented by compassionate conservationists are deliberately or arbitrarily chosen to focus on mammals; inherently not compassionate; and offer ineffective conservation solutions. Compassionate conservation arbitrarily focuses on charismatic species, notably large predators and megaherbivores. The philosophy is not compassionate when it leaves invasive predators in the environment to cause harm to vastly more individuals of native species or uses the fear of harm by apex predators to terrorize mesopredators. Hindering the control of exotic species (megafauna, predators) in situ will not improve the conservation condition of the majority of biodiversity. The positions taken by so-called compassionate conservationists on particular species and on conservation actions could be extended to hinder other forms of conservation, including translocations, conservation fencing, and fertility control. Animal welfare is incredibly important to conservation, but ironically compassionate conservation does not offer the best welfare outcomes to animals and is often ineffective in achieving conservation goals. Consequently, compassionate conservation may threaten public and governmental support for conservation because of the limited understanding of conservation problems by the general public.

Animal personality has become a major topic in animal behaviour. Much recent progress has come from the use of the open-field test, which is routinely used to separate individuals into fast and slow explorers. However, there is no standard way to conduct the test and it is unclear whether the test really measures exploration. Here, we addressed these issues by combining an open-field test with a battery of independent assays intended to assess the convergent and discriminant validity of the behavioural traits suggested to measure exploration in the open-field test. Our study subjects were common mynas, Acridotheres tristis, introduced to Australia. The analyses confirmed that the open-field test allows individuals to be separated according to their propensity to explore, mainly through metrics related to spatial and object examination of the novel cage. However, other metrics classically used to describe exploratory behaviour, such as the latency to enter the novel space, reflected shyness rather than exploration. The open-field test can therefore be a powerful tool to investigate personality, but only if the biological meanings of the metrics derived from the test are properly validated with independent behavioural assays.

Establishment in urbanized environments is associated with changes in physiology, behaviour, and problem-solving. We compared the speed of learning in urban and rural female common mynas, Acridotheres tristis, using a standard visual discrimination task followed by a reversal learning phase. We also examined how quickly each bird progressed through different stages of learning, including sampling and acquisition within both initial and reversal learning, and persistence following reversal. Based on their reliance on very different food resources, we expected urban mynas to learn and reversal learn more quickly but to sample new contingencies for proportionately longer before learning them. When quantified from first presentation to criterion achievement, urban mynas took more 20-trial blocks to learn the initial discrimination, as well as the reversed contingency, than rural mynas. More detailed analyses at the level of stage revealed that this was because urban mynas explored the novel cue-outcome contingencies for longer, and despite transitioning faster through subsequent acquisition, remained overall slower than rural females. Our findings draw attention to fine adjustments in learning strategies in response to urbanization and caution against interpreting the speed to learn a task as a reflection of cognitive ability.

Animal innovations range from the discovery of novel food types to the invention of completely novel behaviours. Innovations can give access to new opportunities, and thus enable innovating agents to invade and create novel niches. This in turn can pave the way for morphological adaptation and adaptive radiation. The mechanisms that make innovations possible are probably as diverse as the innovations themselves. So too are their evolutionary conse- quences. Perhaps because of this diversity, we lack a unifying framework that links mechanism to function. We propose a framework for animal innovation that describes the interactions between mechanism, fitness benefit and evolutionary significance, and which suggests an expanded range of experimental approaches. In doing so, we split innovation into factors (components and phases) that can be manipulated systematically, and which can be investigated both experimentally and with correlational studies. We apply this framework to a selection of cases, showing how it helps us ask more precise questions and design more revealing experiments.

The possibility that variation in the propensity to forage innovatively is attributable to variation in cognition is a matter of debate. Motor flexibility and persistence offer alternative viewpoints. The present study used a computational model to evaluate the relative contribution of these mechanisms to the innovation process. We modeled the effects of low and high motor flexibility on problem-solving performance, which provided a baseline against which to examine how performance changed when combined with operant learning or persistence. We titrated our models through a wide range of parameter values in order to explore where in the outcome space biologically meaningful effect sizes are likely to be detected. The baseline model accurately reproduced an enhancement of performance when relative frequencies of motor expression were balanced (high motor flexibility) rather than skewed (low motor flexibility). Operant learning enhanced performance, but only when agents persisted until they solved and only when motor flexibility was low. In scenarios where agents gave up even if they had not solved, persistence in response to occurrence of secondary cues improved problem solving in both motor flexible and motor inflexible individuals. In scenarios, where the benefits of persistence and learning were compared directly, the benefits of persisting were typically equal, if not greater than those of learning. Given the high metabolic cost of neural tissue, our simulations predict that selection for enhanced problem solving should select for processes that increase persistence (e.g., personality changes) rather than learning.

Innovation and creativity are key defining features of human societies. As we face the global challenges of the twenty-first century, they are also facets upon which we must become increasingly reliant. But what makes Homo sapiens so innovative and where does our high innovation propensity come from? Comparative research on innovativeness in non-human animals allows us to peer back through evolutionary time and investigate the ecological factors that drove the evolution of innovativeness, whereas experimental research identifies and manipulates underpinning creative processes. In commenting on the present theme issue, I highlight the controversies that have typified this research field and show how a paradigmatic shift in our thinking about innovativeness will contribute to resolving these tensions. In the past decade, innovativeness has been considered by many as a trait, a direct product of cognition, and a direct target of selection. The evidence I review here suggests that innovativeness will be hereon viewed as one component, or even an emergent property of a larger array of traits, which have evolved to deal with environmental variation. I illustrate how research should capitalize on taxonomic diversity to unravel the full range of psychological processes that underpin innovativeness in non-human animals.

It is now well established that individuals can differ consistently in their average levels of behaviour across different contexts. There have recently been calls to apply the same adaptive framework to interindividual differences in cognition. These calls have culminated in the suggestion that variation in personality and cognition should correlate. We suggest that both these appealing notions are conceptually and logistically problematic. We identify the first crucial step for establishing any cognition-personality relationship. This is to determine the degree to which cognitive abilities yield consistent task performance. We then suggest how to establish whether such consistency exists. Finally, we discuss why formulating predictions about how cognition might be related to personality is much more difficult than is currently realised.

Macro-ecological comparisons have repeatedly demonstrated that the taxonomic distribution of foraging innovations coincides with the ability to adjust to novel and changing environments. We sought to obtain experimental support for the link between innovative foraging and opportunism by measuring the innovation abilities of two highly successful passerines on the east coast of Australia with very different success strategies. The ecological success of the introduced Indian myna, Acridotheres tristis, has been linked to its ability to occupy opportunistically an ecological niche that most natives cannot, whereas the native noisy miner, Manorina melanocephala, owes its success to its ability to aggressively outcompete other avian species. Indian mynas were significantly more neophobic than noisy miners. Yet, when tested on a range of innovative foraging tasks, Indian mynas consistently outperformed noisy miners. The ability to use the beak in a greater range of ways, and more flexibly, was highly repeatable in Indian mynas, and underpinned their superior problem-solving performance. We discuss the results in the light of potential methodological influences, but also the idea that necessity may facilitate innovation not only in less competitive individuals, as is documented in the literature, but also in species with less competitive lifestyles.

Foraging innovation occurs when animals exploit novel food sources or invent new foraging techniques. Species vary widely in their rates of innovation, and these differences can be quantified using counts of novel behavior observed in the wild. One of the assumed benefits of innovativeness is that it allows species to exploit a wider variety of habitats and foods, enhancing survival when resources are in shortage or when individuals invade new environments. However, the relationship between innovation propensity and ecological generalism lacks firm empirical support. Moreover, innovativeness does not only imply benefits but may also lead to higher risks incurred in the wide array of habitats exploited. In this study, we test whether innovative species exploit a wider variety of habitats and food types as well as face the potential risk of more predators as a consequence of their ecological generalism. Using data for 193 North American bird species in a phylogenetically informed analysis, we find a significant positive relationship between innovation rate and habitat generalism, but not diet breadth. Although habitat generalism is also associated with exposure to a wider variety of predators, there is no direct relationship between innovation rate and predation. Our results suggest that although innovators use a wider variety of habitats, they are not necessarily diet generalists, challenging the classic view that feeding generalism is equivalent to feeding flexibility. © 2011 The Author. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved.

In Pavlovian conditioning, animals acquire a response to a previously neutral stimulus (conditioned stimulus, CS), such as a light, if that stimulus predicts a biologically important event (unconditioned stimulus, US), such as delivery of food. Learning typically occurs when the CS precedes the US (forward conditioning), and not when the CS follows the US (backward conditioning). In social learning about predators, the predator stimulus is considered to be the CS to which observers acquire avoidance responses after the stimulus has been presented in contiguity with an alarmed demonstrator, the US. We tested the prediction that social learning of response to a predator would occur even if the social alarm cues (the US) appeared before the predatory stimulus (the CS). Carib grackles, Quiscalus lugubris, responded to a familiar predator presented at close range by suppressing alarm calls. Presentation of an unfamiliar avian model (black-and-yellow pigeon) also decreased calling, and this inhibition of calling was enhanced following a training session in which the model stimulus was presented in association with grackle alarm calls. Acquired inhibition of calling was independent of the order of presentation of the model and an alarm chorus. These are the first results to indicate that social acquisition of predator avoidance is not dependent upon a particular temporal relationship between predators and social alarm cues. Evolution may have modified some properties of Pavlovian conditioning to accommodate social learning about potentially dangerous stimuli. © 2004 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

In comparison with social learning about food, social learning about predators has received little attention. Yet such research is of potential interest to students of animal cognition and conservation biologists. I summarize evidence for social learning about predators by fish, birds, eutherian mammals, and marsupials. I consider the proposal that this phenomenon is a case of S-S classical conditioning and suggest that evolution may have modified some of the properties of learning to accommodate for the requirements of learning socially about danger. I discuss some between-species differences in the properties of socially acquired predator avoidance and suggest that learning may be faster and more robust in species in which alarm behavior reliably predicts high predatory threat. Finally, I highlight how studies of socially acquired predator avoidance can inform the design of prerelease antipredator training programs for endangered species.

Behavioural plasticity allows animals to adjust rapidly to local environmental conditions, but at the risk of erroneously changing behaviour in response to irrelevant events. Adaptive biases or predispositions constrain learning and reduce such potential costs. Preferential learning about complex biologically-meaningful stimuli, such as predators, has been investigated in only a few systems and there have been no experimental tests for the presence of adaptive biases in a marsupial. We have previously shown that tammar wallabies (Macropus eugenii) became fearful of a model fox (Vulpes vulpes) after it was repeatedly paired with an aversive event. Tammars generalized their acquired response to a cat (Fells catus), but not to a non-predator (juvenile goat, Capra hircus), suggesting that they might have a bias to associate predators with frightening events. The present study tested this idea directly. We used an experimental design identical to that of earlier predator-training experiments, but substituted a model goat for the fox as the stimulus predicting a capture attempt. A control group had the same total experience of the goat and of a human with a net, but without any predictive relationship between these two events. We detected no change in behaviour towards the goat, or to any of an array of control stimuli, as a consequence of training. This finding contrasts strongly with the effects of the same pairing procedure using a fox model. Taken together, these studies provide the first evidence for an adaptive predisposition to acquire a fear of predators in marsupials. Learning processes in this group are thus evolutionarily convergent with those previously described in eutherian mammals.

Many species modify their behaviour in response to the scents of their predators, but species or populations living without predators may lose such abilities. This loss has been suggested to be irreversible, and to constitute a significant hurdle in restoring historical ecosystems. Olfactory predator recognition was studied in two macropodid marsupials - the tammar wallaby (Macropus eugenii) and the red-necked pademelon (Thylogale thetis). Both species are in the 'critical weight range' of Australian native mammals that have been negatively affected by the introduction of novel predators since European settlement. Predator-naive animals were tested by exposing subjects simultaneously to two feeders with either a predator or a herbivore faecal or urine sample beneath the food tray. The presence of predator olfactory cues beneath the feeder did not affect foraging behaviour or feeder use when compared to control stimuli (herbivore faeces or urine). Previous studies have found that predator-experienced herbivorous marsupials modify their behaviour in the presence of predator scents. In contrast, our studies of predator-naïve individuals found no evidence of such selectivity, suggesting that marsupial herbivores may have to learn to modify their behaviour in response to olfactory cues from predators. This implies that the loss of olfactory predator recognition may not be irreversible. Animals translocated from predator-free areas could potentially be trained to recognise the smells of their predator. © 2002 The Zoological Society of London.

Predator recognition is often dependent upon experience. This behavioural plasticity can potentially be exploited to enhance the antipredator behaviour of captive-bred animals, but it is first necessary to understand the specificity of learning. We enhanced the responses of tammar wallabies, Macropus eugenii, to a model fox, Vulpes vulpes, by presenting this novel predator in conjunction with a human simulating a capture procedure. A control group had identical total exposure to fox and human, but with no such predictive relationship between these two events. Animals that experienced paired presentations of fox and human behaved more cautiously towards the fox after training than controls. To assess whether this learnt response was specific to the fox, we presented the animals with an array of visual stimuli both before and after training. The tammars generalized their acquired response from the predator with which they were trained to a predator with which they were not trained (cat, Felis catus), but not to a nonpredator (goat, Capra hircus). Tammars also exhibited a transient increase in response to a model wallaby after training. We suggest that this effect is more likely to reflect social behaviour than generalization of the learnt response from predator to conspecific. Two additional controls revealed that changes in behaviour after training were not attributable to the presentation device and were not caused by a general decrease in response threshold associated with training. Our results suggest that tammar wallabies perceive predators as a natural category. © 2001 The Association for the Study of Animal Behaviour.

Animal reintroductions and translocations are potentially important interventions to save species from extinction, but most are unsuccessful Mortality due to predation is a principal cause of failure. Animals that have been isolated from predators, either throughout their lifetime or over evolutionary time, may no longer express appropriate antipredator behavior. For this reason, conservation biologists are beginning to include antipredator training in pre-release preparation procedures. We describe the evolutionary and ontogenetic circumstances under which antipredator behavior may degenerate or be lost, and we use principles from learning theory to predict which elements can be enhanced or recovered by training. The empirical literature demonstrates that training can improve antipredator skills, but the effectiveness of such interventions is influenced by a number of constraints. We predict that it will be easier to teach animals to cope with predators if they have experienced ontogenetic isolation than if they have undergone evolutionary isolation. Similarly, animals should learn more easily if they have been evolutionarily isolated from some rather than all predators. Training to a novel predator may be more successful if a species has effective responses to similar predators. In contrast, it may be difficult to teach proper avoidance behavior, or to introduce specialized predator-specific responses, if appropriate motor patterns are not already present. We conclude that pre-release training has the potential to enhance the expression of preexisting antipredator behavior. Potential training techniques involve classical conditioning procedures in which animals learn that model predators are predictors of aversive events. However, wildlife managers should be aware that problems, such as the emergence of inappropriate responses, may arise during such training.

We studied the way in which a population of tammar wallabies (Macropus eugenii), which have been isolated from mammalian predators since the last ice age, responded to the sight and sound of historical and ontogenetically and evolutionarily novel predators. Tammars were shown a range of visual stimuli, including taxidermic mounts of two evolutionarily novel predators, a red fox (Vulpes vulpes) and a cat (Felis catus), and a model of an extinct predator, the thylacine (Thylacinus cynocephalus). Controls were a conspecific, the cart on which all mounts were presented, and blank trials in which spontaneous change in behavior was measured. We played back recorded sounds to characterize responses to acoustic cues from predators and to a putative conspecific antipredator signal. Treatments included the howls of dingoes (Canis lupus dingo), an evolutionarily novel predator; calls of a wedge-tailed eagle (Aquila audax), a historical and current predator; and wallaby foot thumps. Controls were the song of an Australian magpie (Gymnorhina tibicen) and a blank trial. After seeing a fox, wallabies thumped their hind feet in alarm, suppressed foraging, and increased looking. The sight of a cat similarly suppressed foraging and increased looking. The sounds of predators did not influence responsiveness, but wallabies foraged less and looked more after thump playbacks. Our results suggest that tammars respond to the sight, but not the sounds, of predators. In contrast, the response to foot thumps demonstrates that this particular sound functions as an antipredator signal. We suggest that responsiveness to visual cues has been preserved under relaxed selection because predator morphology is convergent, but vocalizations are not.

Mammals can navigate through path integration (dead reckoning) by updating their position on the basis of internal signals generated during locomotion, without using any external references. However, being open to cumulative errors, path integration remains functional over short excursions only, unless corrected by familiar landmarks. That such a corrective process may occur was examined in golden hamsters during hoarding excursions occurring in darkness, within a large open arena. The subjects proceeded from their peripheral nest to a feeding site on a platform. If the annuals were rotated during food pouching, their subsequent homing behavior was disoriented, self-generated positional information having been disrupted. By contrast, when the subjects were rotated at the food source and then briefly presented with the familiar visual environment, they returned homeward, albeit not very precisely. Thus, the animals may have taken an approximate positional fix or reset their internal compass only.