Behavioral innovation, defined as the ability to exhibit novel behaviors that may contribute to problem-solving and adaptability, has been increasingly recognized as a key factor in species’ resilience to environmental shifts. Here we investigate the association between behavioral innovation and climatic niche breadths (the range of climatic conditions a species can tolerate) across 9338 bird species, representing the majority of extant birds, exploring its potential role in coping with climatic variability. We quantified climatic niches using high-resolution spatial and bioclimatic data to capture both species-overall extremes and among-locality variations. By using Bayesian Phylogenetic Generalized Linear Mixed Models, we analyzed correlations between these realized climatic niche breadths and two metrics of behavioral innovation—innovativeness (the propensity to exhibit novel behaviors) and innovation rate (the frequency of such behaviors)—while incorporating ecological and life-history traits as covariates. Innovativeness significantly correlates with broader climatic niche breadths for both temperature and precipitation. In contrast, innovation rate shows only a positive association with precipitation niche breadth and no significant correlation with any temperature niche metrics. Our findings reveal that while innovativeness significantly correlates with broader climatic niche breadths in birds, further variation in climatic niche breadth among innovative species is minimally associated with their innovation rates. This relationship is linked to a distinct spatial pattern: for temperature, innovative species exhibit broader niches alongside both wider within-locality tolerance and greater variation among localities; for precipitation, broader niches are associated primarily with greater variation among localities, despite having narrower within-locality niches. These results highlight that integrating innovativeness into climate vulnerability assessments could better capture resilience, complementing established predictors.

Foraging skills influence food intake and could therefore also play a role in mate choice decision. Previous empirical work has shown that individuals benefit from being in groups that include individuals with a variety of foraging skills as this increases foraging success. This idea, formalized in the skill-pool hypothesis, may extend to mate choice. Diverse foraging skills can expand the foraging niche of a pair and benefit offspring through enhanced parental provisioning, and exposure to a broader foraging skillset. To test this idea, we trained captive female and male budgerigars to solve one of two different novel foraging puzzle boxes. Then, females simultaneously observed two males that could solve either the same or the other box, and assessed female preferences in a binary mate choice apparatus. Females preferred males with foraging skills that differed from their own, independent of the skill type and the number of times males solved the foraging puzzle. These findings show that foraging skills can influence social preferences, including in a mate choice context, and support intraspecific diversity in foraging skills.

Food sharing is very common in the animal kingdom. Despite extensive research, the mechanisms underlying food sharing remain debated. Moreover, the majority of studies on food sharing in non-human animals have been conducted under controlled environments. The natural behavioral characteristics and ecological factors influencing the natural selection of food sharing are still not well understood. In this study, we introduce a method to examine food-sharing behaviors in wild birds within their natural habitat. Using two types of feeders-one permitting food sharing with conspecifics and the other providing exclusive access to food-along with infrared cameras to record feeder-triggering events, we found that azure-winged magpies did not exhibit proactive food-sharing behaviors. However, they did exhibit passive food-sharing behaviors under conditions of low food availability. Consistent with the harassment-avoidance hypothesis, the birds prioritized the sharing feeders to decrease harassment from food snatching when food was limited. These findings suggest that food sharing is likely shaped into a passive behavioral pattern under limited resources conditions, which induce conflicts within social groups. This context-dependent strategy may effectively reduce harassment costs, optimize individual access to resources to maximize individual benefits, and potentially enhance the survival of other group members.

Rodents are known to interact with seed plants in three different ways, including predation in situ, scatter hoarding and larder hoarding of seeds. These behaviours span a spectrum from mutualistic seed dispersal to predation, and they are related to species' and environmental characteristics. We used interaction networks to evaluate the structure and drivers of rodent-seed plant interactions, including geography, phylogeny and traits at continental scales. We constructed five aggregated networks, each representing a continent and containing three subnetworks defined by foraging behaviours, tested questions about their network structures and analysed the driving signals shaping rodent-seed plant interactions at network and species levels. Rodent-seed plant networks varied across continents. We found most rodents exhibited a significant propensity for one foraging behaviour and detected significant modular structures in both aggregated networks and subnetworks. We detected significant co-phylogenetic signals between rodents and seed plants. Distance matrix-based regressions on interaction and module dissimilarity of rodents suggest geographical and phylogenetic forces are important in the assembly of rodent-seed plant networks. In addition, multiple species traits correlated with the roles of rodents within aggregated networks; however, the specific traits associated with these roles varied among interaction types. Our results highlight that geography and phylogenetics are dominant in structuring the architecture of rodent-seed plant networks at continental scales and reveal challenges regarding spatial and taxa coverage in rodent-seed plant interactions.

The ability to understand relational concepts, such as 'same' and 'different', is a critical feature of human cognition. To what extent non-human animals can acquire such concepts and which factors influence their learning are still unclear. We examined the acquisition and the breadth of understanding the 'same-different' concept in budgerigars (Melopsittacus undulatus). Budgerigars trained to discriminate stimulus pairs in which two identical figures were either the same or different size (Experiment 1) successfully generalized the discrimination to novel stimuli belonging to various categories (size, colour, shape, geometric type and number of dots). The results of Experiment 1 thus demonstrate that budgerigars can perceive and generalize the same-different concept across dimensions after training with a limited set of stimuli differing along a single dimension. In contrast, while most budgerigars trained to discriminate two pairs of discs that were either the same or different in colour (Experiment 2) could generalize the discrimination to novel stimuli within the training category (colour), only few generalized the discrimination to another category suggesting a generalization based on perceptual similarity. The results thus show that whether budgerigars generalize a relationship by conceptual or perceptual similarity depends on the nature of the training stimuli.

Scatter- and larder hoarding are the primary strategies of food-hoarding animals and have important implications for plant-animal interactions and plant recruitment. However, their origins and influencing factors have not been fully investigated across a wide range of taxa. Our systematic literature search amassed data for 183 seed-hoarding rodent species worldwide and tested relationships of seed-hoarding behaviours with phylogenetic signal, functional traits and environmental factors. We found that the evolution of hoarding strategies was not random in phylogeny, and scatter hoarding originated independently multiple times from larder hoarding. Rodents with higher encephalisation quotient (relative brain size), omnivorous diet (related to dependence on seeds) and inhabiting lower latitudes were disproportionately likely to scatter hoard. Despite body mass's potential relationship with competition through food defence, it was associated with food-hoarding strategy only in a few families. Our results show the need to study the community and ecological context of food-hoarding behaviours.

Scatter- and larder hoarding are the primary strategies of food-hoarding animals and have important implications for plant-animal interactions and plant recruitment. However, their origins and influencing factors have not been fully investigated across a wide range of taxa. Our systematic literature search amassed data for 183 seed-hoarding rodent species worldwide and tested relationships of seed-hoarding behaviours with phylogenetic signal, functional traits and environmental factors. We found that the evolution of hoarding strategies was not random in phylogeny, and scatter hoarding originated independently multiple times from larder hoarding. Rodents with higher encephalisation quotient (relative brain size), omnivorous diet (related to dependence on seeds) and inhabiting lower latitudes were disproportionately likely to scatter hoard. Despite body mass's potential relationship with competition through food defence, it was associated with food-hoarding strategy only in a few families. Our results show the need to study the community and ecological context of food-hoarding behaviours.

In recent years, researchers have been attempting to relate differences in personality (e.g., boldness, aggressiveness, exploration tendency) to variation in cognition (performances in tasks that require learning, reasoning, attention, or memory, etc.) both theoretically and empirically. However, it is unclear on what basis personality and cognition might be associated with each other. Previous theory suggests a connection between fast-slow personality types and cognitive speed-accuracy tradeoffs. In this study, we tested this hypothesis in budgerigars and found that, in their 1st associative learning, birds with fast personality (less fearful of handling stress) were fast learners in the beginning, while slow personality individuals improved faster, but both types of birds did not differ in accuracy. However, these relationships were context-dependent. No significant relationship was found in subsequent learning tasks (reversal learning and a 2nd associative learning) in the familiar context (task setup and apparatus similar to the 1st associative learning). We then conducted a problem-solving experiment with novel setup and apparatus to test 1 possible explanation that the association between personality and cognition in the 1st associative learning might be caused by noncognitive constraint, such as fearfulness when facing novel task setup and apparatus. We found that fast individuals interacted more with the problem box and solved it, whereas the slow birds were not. We suggest that personalities can influence cognitive performances and trigger a cognitive speed-improvement tradeoff under the novel context. However, there are no consistent cognitive styles that co-varied with different personalities.

In an earlier study (Chen et al., 2019, Science, 363(6423), 166-167), we showed that budgerigar, Melopsittacus undulatus, females increase their preference for males that were observed solving two extractive foraging problems. Camacho-Alpizar et al. (2020, Animal Behaviour, 165, e1-e3) question whether this outcome shows that females evaluate the cognitive skills of males. Their main argument is that individual differences in problem solving are often due to differences in noncognitive abilities. Here we outline the differences between the use of problem-solving tasks as it is mostly done and how we used it in our study. We argue that our design maximizes the chance that observed differences in male problem solving indicate differences in learning abilities to an observing female. We agree with Camacho-Alpizar et al. that the topic of the evolution of cognitive abilities through sexual selection deserves further study and hope our study (Chen et al., 2019), Camacho-Alpizar et al.'s comment and this reply will stimulate further research. (c) 2020 The Authors. Published by Elsevier Ltd on behalf of The Association for the Study of Animal Behaviour. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Many animal species can detect dependencies between adjacent visual or auditory items in a string. Compared with adjacent dependencies, detecting nonadjacent dependencies, as present in linguistic constructions, is more challenging as this requires detecting a relation between items irrespective of the number and nature of the intervening items. There is limited evidence that nonhuman animals can detect such dependencies. An animal group in which such abilities might be expected is songbirds, which have learned songs consisting of a series of vocal elements given in specific sequences. So far no songbird (or other bird species) has been tested for its ability to detect nonadjacent dependencies. We examined whether zebra finches can detect the dependencies between items at the edges of artificially arranged strings of song elements. Zebra finches were trained to discriminate 2 sets of dependent song elements that always appeared in the same order (A and B; C and D), from other element combinations (AD, AC, BD, CB, CA, DB). The element combinations were separated by intervening (I) elements. Subsequent tests revealed that the finches could generalize the learned dependencies over different numbers and types of intervening items. Our findings show that the ability for detecting nonadjacent dependencies is not limited to humans or primates, and lend support to theories that suggest that nonadjacent dependencies can be learned by a nonlinguistic associative learning process. (PsycINFO Database Record

Adding an affix to transform a word is common across the world languages, with the edges of words more likely to carry out such a function. However, detecting affixation patterns is also observed in learning tasks outside the domain of language, suggesting that the underlying mechanism from which affixation patterns have arisen may not be language or even human specific. We addressed whether a songbird, the zebra finch, is able to discriminate between, and generalize, affixation-like patterns. Zebra finches were trained and tested in a Go/Nogo paradigm to discriminate artificial song element sequences resembling prefixed and suffixed 'words.' The 'stems' of the 'words,' consisted of different combinations of a triplet of song elements, to which a fourth element was added as either a 'prefix' or a 'suffix.' After training, the birds were tested with novel stems, consisting of either rearranged familiar element types or novel element types. The birds were able to generalize the affixation patterns to novel stems with both familiar and novel element types. Hence, the discrimination resulting from the training was not based on memorization of individual stimuli, but on a shared property among Go or Nogo stimuli, i.e., affixation patterns. Remarkably, birds trained with suffixation as Go pattern showed clear evidence of using both prefix and suffix, while those trained with the prefix as the Go stimulus used primarily the prefix. This finding illustrates that an asymmetry in attending to different affixations is not restricted to human languages.

In birds, the trade-off between the quality and number of nestlings is one of the most important theories of the evolution of life history of birds, which is closely related with climate. We investigated variation in egg and clutch size of the Black Redstart (Phoenicurus ochruros) on the northeastern edge of the Qinghai-Tibetan Plateau in order to explore and test the relation between egg size and clutch size and the rules governing the variation in these two components with climate change.

Abstracting syntactic rules is critical to human language learning. It is debated whether this ability, already present in young infants, is human- and language specific or can also be found in non-human animals, indicating it may arise from more general cognitive mechanisms. Current studies are often ambiguous and few have directly compared rule learning by humans and non-human animals. In a series of discrimination experiments, we presented zebra finches and human adults with comparable training and tests with the same artificial stimuli consisting of XYX and XXY structures, in which X and Y were zebra finch song elements. Zebra finches readily discriminated the training stimuli. Some birds also discriminated novel stimuli when these were composed of familiar element types, but none of the birds generalized the discrimination to novel element types. We conclude that zebra finches show evidence of simple rule abstraction related to positional learning, suggesting stimulus-bound generalization, but found no evidence for a more abstract rule generalization. This differed from the human adults, who categorized novel stimuli consisting of novel element types into different groups according to their structure. The limited abilities for rule abstraction in zebra finches may indicate what the precursors of more complex abstraction as found in humans may have been like.

Learning sequences is of great importance to humans and non-human animals. Many motor and mental actions, such as singing in birds and speech processing in humans, rely on sequential learning. At least two mechanisms are considered to be involved in such learning. The chaining theory proposes that learning of sequences relies on memorizing the transitions between adjacent items, while the positional theory suggests that learners encode the items according to their ordinal position in the sequence. Positional learning is assumed to dominate sequential learning. However, human infants exposed to a string of speech sounds can learn transitional (chaining) cues. So far, it is not clear whether birds, an increasingly important model for examining vocal processing, can do this. In this study we use a Go-Nogo design to examine whether zebra finches can use transitional cues to distinguish artificially constructed strings of song elements. Zebra finches were trained with sequences differing in transitional and positional information and next tested with novel strings sharing positional and transitional similarities with the training strings. The results show that they can attend to both transitional and positional cues and that their sequential coding strategies can be biased toward transitional cues depending on the learning context. This article is part of a Special Issue entitled: In Honor of Jerry Hogan. (C) 2014 Elsevier B.V. All rights reserved.

Adding an affix to transform a word is common across the world languages, with the edges of words more likely to carry out such a function. However, detecting affixation patterns is also observed in learning tasks outside the domain of language, suggesting that the underlying mechanism from which affixation patterns have arisen may not be language- or even human-specific. We addressed whether a songbird, the zebra finch, is able to discriminate between, and generalize about, affixation patterns. Zebra finches were trained and tested in a Go/Nogo paradigm to discriminate artificial song element sequences resembling prefixed and suffixed ‘words’. The ‘stems’ of the ‘words’, consisted of different combinations of a triplet of song elements, to which a fourth element was added as either a ‘prefix’ or a ‘suffix’. After training, the birds were tested with novel stems, consisting of either rearranged familiar element types or of novel element types. The birds were able to generalize the affixation patterns to novel stems with both familiar and novel element types. Hence the discrimination resulting from the training was not based on memorization of individual stimuli, but on a shared property among Go or Nogo stimuli, i.e. affixation patterns. Remarkably, birds trained with suffixation as Go pattern showed clear evidence of using both prefix and suffix, while those trained with the prefix as the Go-stimulus used primarily the prefix. This may imply an interesting parallel to the asymmetry in the type of affixation preferred in human languages. to claim that such an experiment demonstrates the presence of the full formal notion of affixations in a non-human animal. What it can show is whether birds have the competence to detect surface transformations similar to different affixation patterns (prefix and suffix) and link these to different ‘meanings’ – in this case either a food reward or a mild punishment. The linkage of each affixation pattern to a different reward is also an advantage of using a Go/NoGo paradigm over a habituation paradigm as used in the tamarin study (Endress, Cahill et al., 2009). The habituation paradigm can tell whether animals spontaneously detect a change in a pattern, but detecting such a change is not linked to any consequence. The Go/Nogo not only tests whether the animals detect a difference, but also whether they can link this to a difference in consequences, analogous to human infants that have to learn over time how different affixations alter word meanings.. We also examine whether zebra finches can learn both prefixation and suffixation patterns equally well, or have a bias to be more sensitive to one over the other, as has been suggested for human languages (Cutler, Hawkins et al., 1985; Dryer, 2005; St Clair, Monaghan et al., 2009). We show that the zebra finches are able to learn both regularities. Remarkably, birds that had been trained with prefixation as Go pattern used predominantly the prefix to make their discrimination while birds trained with suffixation as Go pattern used both prefix and suffix.

A hallmark of the human language faculty is the use of syntactic rules. The natural vocalizations of animals are syntactically simple, but several studies indicate that animals can detect and discriminate more complex structures in acoustic stimuli. However, how they discriminate such structures is often not clear. Using an artificial grammar learning paradigm, zebra finches were tested in a Go/No-go experiment for their ability to distinguish structurally different three-element sound sequences. In Experiment 1, zebra finches learned to discriminate ABA and BAB from ABB, AAB, BBA, and ABB sequences. Tests with probe sounds consisting of four elements suggested that the discrimination was based on attending to the presence or absence of repeated A- and B-elements. One bird generalized the discrimination to a new element type. In Experiment 2, we continued the training by adding four-element songs following a 'first and last identical versus different' rule that could not be solved by attending to repetitions. Only two out of five birds learned the overall discrimination. Testing with novel probes demonstrated that discrimination was not based on using the 'first and last identical' rule, but on attending to the presence or absence of the individual training stimuli. The two birds differed in the strategies used. Our results thus demonstrate only a limited degree of abstract rule learning but highlight the need for extensive and critical probe testing to examine the rules that animals (and humans) use to solve artificial grammar learning tasks. They also underline that rule learning strategies may differ between individuals.

Natural selection should favor flexibility in nest site selection when environmental variability influences individual fitness. Birds can modify their reproductive behaviors in response to predation cues. Similar to predation risk, human disturbance may cause birds to exhibit parental antipredator behavior. Effects of human disturbance on nest site selection of Black Redstarts ( Phoenicurus ochruros ) were investigated from 2006 to 2009. Black redstarts altered their manner of concealing nests following human disturbance. The Black Redstarts were found to shift their nests to deeper locations in the cavities in the subsequent breeding season after human disturbance. In an undisturbed study plot, nests were not well hidden in the first year but shifted to deeper positions in the nest cavities following disturbance from researchers. The depth in the nest cavity at which banded individual Black Redstarts nested was deeper than its previous nest location depth after human disturbance. The results obtained in this study suggest that the Black Redstarts cognize human disturbance as a predation risk and exhibit adaptive behavioral plasticity in nest site selection associated with concealment.