Hand‐Rearing Wild Caribou Calves for Studies of Nutritional Ecology

Caribou (Rangifer tarandus) are considered difficult to hand‐rear in captivity because they are sensitive to the composition and volume of formulated milks. We used a strict feeding schedule and a commercial milk formula designed specifically for caribou to bottle‐feed neonates captured from five wild caribou herds in Alaska. Under a feeding protocol adjusted for age and mass, the growth rates and body mass of 26 hand‐reared caribou calves to weaning were similar to those of three maternally nursed caribou. This protocol allows caretakers to hand‐rear caribou that are as representative as possible of maternally raised neonates. Zoo Biol. 32:163–171, 2013. © 2012 Wiley Periodicals, Inc.     

Hand‐raising a spectral tarsier (Tarsius tarsier) at the Ueno Zoological Gardens

On February 10, 2008, a newborn male spectral tarsier (Tarsius tarsier) was found on the floor of the indoor exhibit room in the Small Mammal House of the Ueno Zoological Gardens. The dam showed no signs of providing maternal care and therefore we decided to hand‐raise the infant. Its birth weight was 18.7 g. We placed the dam and infant in an incubator and gave 12.5–25% formula (for kittens), until the 145th day after birth. We limited the volume of formula intake to avoid excessive intake and to prevent diarrhea. For nutrition enrichment, we added a chicken liver homogenate to the formula 1–3 times per day. The infant was given a sunbath for 10 min on the 28th day. He showed no serious decline in health, except for diarrhea that occurred during the first few days after birth. He ate a small cricket for the first time on the 50th day and easily caught mealworms on his own on the 105th day. Gradual changes in feeding times, formula concentration, and the nutritionally enriched formula were essential for successfully hand‐raising the tarsier. Zoo Biol 30:218–224, 2011. © 2010 Wiley‐Liss, Inc.     

Food Acceptance and Social Learning Opportunities in Semi‐Free Eastern Chimpanzees (Pan troglodytes schweinfurthii)

When confronted with novel foods, chimpanzees’ responses combine a mixture of curiosity and cautiousness. Once the item is in the mouth, the initial cautiousness is followed by an aversion to bitter taste that is mediated mainly by the TAS2R gene family. For instance, variations on the TAS2R38 locus which has been studied extensively in humans have been associated with different acceptance of bitter substances. Surprisingly, while cautiousness and bitter taste aversion were selected to prevent any risk of poisoning, very few studies on novel food acceptance have included the vegetative parts of plants. Moreover, the studies were usually carried out with captive apes faced to a very restricted variety of non‐toxic plants, hardly making the results representative. This study aims to replicate previous findings obtained in zoos while controlling for these limitations. We provided nine subgroups of eastern chimpanzees (Pan troglodytes schweinfurthii) living in the Ugandan sanctuary of Ngamba Island with novel plants known to be consumed by wild chimpanzees of the same subspecies, as well as domestic plants, wild sapota fruit and grey clay used by human local communities. We also genotyped their TAS2R38 gene. Our results confirm the very low genetic heterogeneity for TAS2R38 in this chimpanzee subspecies. Chimpanzees were particularly cautious towards the vegetative parts of novel plants, likely reflecting their behavioural strategy for avoiding toxic compounds. We also confirmed their higher propensity towards testing sapota and clay, reflecting their ability to expand their diet. In contrast with the results found in zoos, familiar and novel less‐palatable vegetative parts of plants did not elicit many interindividual observations. This may be explained by the items presented, which could have been so novel to be considered as enrichment in captive conditions, where the apes are rarely exposed to plants.     

Task‐Dependent Differences in Learning by Subordinate and Dominant Wild Arabian Babblers

Learning and innovation abilities have been studied extensively in flocking birds, but their importance and relevance in cooperatively breeding birds have been relatively unexplored. We studied the acquisition of novel foraging skills in 14 groups of wild, cooperatively breeding Arabian babblers (Turdoides squamiceps). While in a previous study we found that subordinate individuals were usually the first to learn to remove black rubber lids from a foraging grid, here we show that dominant individuals were the first to succeed in shifting from these black rubber lids to newly introduced white rubber lids. We also found that in all groups where one forager learned to shift to the white lids, the rest of the foragers also learned to do so, suggesting that this behaviour may be transmitted among group members. Although dominant individuals were almost always the first to remove white lids, once starting to remove white lids, dominants and subordinates learned equally well to prefer white over black lids based on differential reinforcement (food was provided only under white lids). Together with our previous study, our results suggest that differences in learning between dominants and subordinates may be task‐specific, which may represent different cognitive strategies: subordinates may explore a more diverse range of foraging opportunities, while dominants may be better at generalizing from familiar tasks to similar ones.     

Social carry‐over effects underpin trans‐seasonally linked structure in a wild bird population

Spatial structure underpins numerous population processes by determining the environment individuals' experience and which other individuals they encounter. Yet, how the social landscape influences individuals' spatial decisions remains largely unexplored. Wild great tits (Parus major) form freely moving winter flocks, but choose a single location to establish a breeding territory over the spring. We demonstrate that individuals' winter social associations carry‐over into their subsequent spatial decisions, as individuals breed nearer to those they were most associated with during winter. Further, they also form territory boundaries with their closest winter associates, irrespective of breeding distance. These findings were consistent across years, and among all demographic classes, suggesting that such social carry‐over effects may be general. Thus, prior social structure can shape the spatial proximity, and fine‐scale arrangement, of breeding individuals. In this way, social networks can influence a wide range of processes linked to individuals' breeding locations, including other social interactions themselves.     

The Effect of Familiarity with Demonstrators on Social Learning in Three‐Spined Sticklebacks (Gasterosteus aculeatus)

Social learning is an important process in the spread of information, especially in changing environments where inherited behaviors may not remain relevant. In many species, the decision of whom to trust to have reliable information depends on the relationship between individuals. Many fish species, including three‐spined sticklebacks, preferentially associate with familiar individuals. Previous studies in three‐spined sticklebacks have provided mixed evidence about the effect of familiarity on social learning in this species. Therefore, this study further explores familiarity and social learning in sticklebacks, specifically from a demonstrator‐focused perspective. We found that in a food patch discrimination task, individuals with unfamiliar demonstrators performed significantly better than those with familiar demonstrators. In a problem‐solving task, we found that focal fish attended to the behavior of demonstrators, but we did not detect an effect of familiarity on performance, and indeed the proportion of individuals to solve the task after observing demonstrators was low. These results suggest that sticklebacks have a preference for unfamiliar demonstrators, but that the use of social information varies depending on context.     

Fractal Long‐Range Correlations in Behavioural Sequences of Wild Chimpanzees: a Non‐Invasive Analytical Tool for the Evaluation of Health

Quantitative evaluation of health impairments in wild chimpanzees was explored using fractal long‐range correlations of behavioural sequences. The health status of 13 chimpanzees in the Mahale Mountains National Park, Tanzania was evaluated non‐invasively using standard behavioural observation and parasitological analysis of stool samples. Based on these data, individuals were classified as being either healthy or sick. Behavioural sequences were analysed and shown to exhibit long‐range power law correlations. The behavioural sequences of individuals in healthy and sick states were quantitatively evaluated using detrended fluctuation analysis of social and non‐social behaviours within behavioural sequences. These values were compared and significant differences in long‐range correlations were found between health states. Sex differences were also noted, with female social behaviour displaying a larger fractal dimension than male social behaviour. The fractal dimension of females declined significantly in sick individuals. This analysis of behaviour provides a new and effective non‐invasive method to record and evaluate the general state of health and related stress of animals in the wild. Possible applications of this method in captive situations include the monitoring and evaluating of stress levels over time.     

Tolerance and Social Facilitation in the Foraging Behaviour of Free‐Ranging Crows (Corvus corone corone; C. c. cornix)

Social foraging provides animals with opportunities to gain knowledge about available food. Studies indicate that animals are influenced by social context during exploration and are able to learn socially. Carrion and hooded crows, which are opportunistic generalists with flexible social systems, have so far received little focus in this area. We combined observational and experimental approaches to investigate social interactions during foraging and social influences on crow behaviour within a free‐ranging population at Vienna Zoo, which included 115 individually marked crows. We expected the crows to be tolerant of conspecifics during foraging due to high food abundance. We predicted that social context would enhance familiar object exploration, as well as a specific foraging strategy: predation by crows on other species. We found that crows were highly tolerant of one another, as reflected by their high rates of cofeeding – where they fed directly beside conspecific(s) – relative to affiliative or agonistic interactions. Evidence for social facilitation – when the observer's behaviour is affected by the mere presence of a model – was found in both object exploration and predation behaviour. Specifically, crows touched the objects more frequently when others were present (whilst only approaching the objects when alone), and conspecifics were present more frequently during predation events involving the high‐risk target species. Evidence for enhancement during object exploration – where the observer's attention is drawn to a place or object by a model's actions – was not confirmed in this context. Our results highlight the role played by the presence of conspecifics across different contexts: natural foraging behaviour, familiar object exploration and a specific foraging strategy. To our knowledge, this is one of the first corvid studies aimed at teasing apart specific social influence and learning mechanisms in the field. These crows therefore make promising candidates for studying social learning and its consequences under naturalistic conditions.     

Social learning and human mate preferences: a potential mechanism for generating and maintaining between-population diversity in attraction

Inspired by studies demonstrating mate-choice copying effects in non-human species, recent studies of attractiveness judgements suggest that social learning also influences human preferences. In the first part of our article, we review evidence for social learning effects on preferences in humans and other animals. In the second part, we present new empirical evidence that social learning not only influences the attractiveness of specific individuals, but can also generalize to judgements of previously unseen individuals possessing similar physical traits. The different conditions represent different populations and, once a preference arises in a population, social learning can lead to the spread of preferences within that population. In the final part of our article, we discuss the theoretical basis for, and possible impact of, biases in social learning whereby individuals may preferentially copy the choices of those with high status or better access to critical information about potential mates. Such biases could mean that the choices of a select few individuals carry the greatest weight, rapidly generating agreement in preferences within a population. Collectively, these issues suggest that social learning mechanisms encourage the spread of preferences for certain traits once they arise within a population and so may explain certain cross-cultural differences.     

Theorizing human impacts into ecological restoration is not a slippery slope,but a toehold for reaching social‐ecological resilience: a counter‐response to McDonald et al. (2019)

In their reply, McDonald et al. have misconstrued several crucial points from our article. In this counter‐response, we clarify our concerns with the Standards as a document with global implications. We highlight our concern with framing preindustrial indigenous peoples' impacts as natural and the colonial connotations of such an assumption. We also discuss practical issues that arise from the Standards' conceptualization of natural variation and suggest avenues for developing frameworks that do not rely on a nature‐culture dichotomy or naturalization of indigenous landscapes.     

Quantitative trait locus mapping and analysis of heritable variation in affiliative social behavior and co‐occurring traits

Humans exhibit broad heterogeneity in affiliative social behavior. Twin and family studies show that individual differences in core dimensions of social behavior are heritable, yet there are knowledge gaps in understanding the underlying genetic and neurobiological mechanisms. Animal genetic reference panels (GRPs) provide a tractable strategy for examining the behavioral and genetic architecture of complex traits. Here, using males from 50 mouse strains from the BXD GRP, 4 domains of affiliative social behavior—social approach, social recognition, direct social interaction (DSI) (partner sniffing) and vocal communication—were examined in 2 widely used behavioral tasks—the 3‐chamber and DSI tasks. There was continuous and broad variation in social and nonsocial traits, with moderate to high heritability of social approach sniff preference (0.31), ultrasonic vocalization (USV) count (0.39), partner sniffing (0.51), locomotor activity (0.54‐0.66) and anxiety‐like behavior (0.36). Principal component analysis shows that variation in social and nonsocial traits are attributable to 5 independent factors. Genome‐wide mapping identified significant quantitative trait loci for USV count on chromosome (Chr) 18 and locomotor activity on Chr X, with suggestive loci and candidate quantitative trait genes identified for all traits with one notable exception—partner sniffing in the DSI task. The results show heritable variation in sociability, which is independent of variation in activity and anxiety‐like traits. In addition, a highly heritable and ethological domain of affiliative sociability—partner sniffing—appears highly polygenic. These findings establish a basis for identifying functional natural variants, leading to a new understanding typical and atypical sociability.     

The influence of AVPR1A genotype on individual differences in behaviors during a mirror self‐recognition task in chimpanzees (Pan troglodytes)

The mark/rouge test has been used to assess mirror self‐recognition (MSR) in many species. Despite consistent evidence of MSR in great apes, genetic or non‐genetic factors may account for the individual differences in behavioral responses that have been reported. We examined whether vasopressin receptor gene (AVPR1A) polymorphisms are associated with MSR‐related behaviors in chimpanzees since vasopressin has been implicated in the development and evolution of complex social relations and cognition and chimpanzees are polymorphic for the presence of the RS3‐containing DupB region. We compared a sample of DupB+/? and DupB?/? chimpanzees on a mark test to assess its role on social behavior toward a mirror. Chimpanzees were administered two, 10‐min sessions where frequencies of mirror‐guided self‐directed behaviors, contingent actions and other social behaviors were recorded. Approximately one‐third showed evidence of MSR and these individuals exhibited more mirror‐guided self‐exploratory behaviors and mouth contingent actions than chimpanzees not classified as passers. Moreover, DupB+/? males exhibited more scratching and agonistic behaviors than other male and female cohorts. Our findings support previous studies demonstrating individual differences in MSR abilities in chimpanzees and suggest that AVPR1A partly explains individual differences in MSR by influencing the behavioral reactions of chimpanzees in front of a mirror.     

Age and size at maturity: A quantitative review of diet‐induced reaction norms in insects

Optimality models predict that diet‐induced bivariate reaction norms for age and size at maturity can have diverse shapes, with the slope varying from negative to positive. To evaluate these predictions, we perform a quantitative review of relevant data, using a literature‐derived database of body sizes and development times for over 200 insect species. We show that bivariate reaction norms with a negative slope prevail in nearly all taxonomic and ecological categories of insects as well as in some other ectotherm taxa with comparable life histories (arachnids and amphibians). In insects, positive slopes are largely limited to species, which feed on discrete resource items, parasitoids in particular. By contrast, with virtually no meaningful exceptions, herbivorous and predatory insects display reaction norms with a negative slope. This is consistent with the idea that predictable resource depletion, a scenario selecting for positively sloped reaction norms, is not frequent for these insects. Another source of such selection—a positive correlation between resource levels and juvenile mortality rates—should similarly be rare among insects. Positive slopes can also be predicted by models which integrate life‐history evolution and population dynamics. As bottom‐up regulation is not common in most insect groups, such models may not be most appropriate for insects.     

A robust feeding strategy to maintain set‐point glucose in mammalian fed‐batch cultures when input parameters have a large error

Industrial CHO cell cultures run under fed‐batch conditions are required to be controlled in particular ranges of glucose, while glucose is constantly consumed and must be replenished by a feed. The most appropriate feeding rate is ideally stoichiometric and adaptive in nature to balance the dynamically changing rate of glucose consumption. However, high errors in biomass and glucose estimation as well as limited knowledge of the true metabolic state challenge the control strategy. In this contribution, we take these errors into account and simulate the output with uncertainty trajectories in silico in order to control glucose concentration. Other than many control strategies, which require parameter estimation, our assumptions are founded on two pillars: (i) first principles and (ii) prior knowledge about the variability of fed‐batch CHO cell culture. The algorithm was exposed to an in‐silico Design of Experiments (DoE), in which variations of parameters were changed simultaneously, such as clone‐specific behavior, precision of equipment and desired control range used. The results demonstrate that our method achieved the target of holding the glucose concentration within an acceptable range. A robust and sufficient level of control could be demonstrated even with high errors for biomass or metabolic state estimation. In a time where blockbuster drugs are queuing up for time slots of their production, this transferable control strategy that is independent of tedious establishment runs may be a decisive advantage for rapid implementation during technology transfer and scale up and decrease in campaign change over time. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:317–336, 2017