1,721,127 research outputs found
Use of statistical programs for nonparametric tests of small samples often leads to incorrect P values: examples from Animal Behaviour
No full textIn recent years, the use of software for the calculation of statistical tests has become widespread. For many nonparametric tests, a number of statistical programs calculate significance levels based on algorithms appropriate for large samples only (‘asymptotic testing’). In behavioural sciences, however, small samples are common. In nonparametric tests, this requires the use of the ‘exact’ variant of the respective statistical test. Using the asymptotic variant of a nonparametric test with small sample sizes usually yields an incorrect P value, and consequently, this may lead to a false acceptance or rejection of the null hypothesis. With the frequent application of statistical packages, the inappropriate use of the asymptotic variant has unfortunately become quite common. We examined the results of nonparametric tests with small sample sizes published in a recent issue of Animal Behaviour and found that in more than half of the articles concerned, the asymptotic variant had apparently been inappropriately used and incorrect P values had been presented. Before describing this analysis of papers published in Animal Behaviour, we provide a short overview of the differences between asymptotic and exact testing and discuss the consequences of the inappropriate use of asymptotic tests
Older Barbary macaques show limited capacity for self-regulation to avoid hazardous social interactions
No full textAccording to the Strength-and-Vulnerability-Integration (SAVI) model, older people are more motivated to avoid negative affect and high arousal than younger people. To explore the biological roots of this effect, we investigate communicative interactions and social information processing in Barbary macaques (Macaca sylvanus) living at ‘La Forêt des Singes’ in Rocamadour, France. The study combines an analysis of the production of (N = 8185 signals, 84 signallers) and responses to communicative signals (N = 3672 events, 84 receivers) with a field experiment (N = 166 trials, 45 subjects). Here we show that older monkeys are not more likely to specifically ignore negative social information or to employ avoidance strategies in stressful situations, although they are overall less sociable. We suggest that the monkeys have only a limited capacity for self-regulation within social interactions and rather rely on general avoidance strategies to decrease the risk of potentially hazardous social interactions
Spatiotemporal Patterns of Sleeping Site Use of Guinea Baboon Parties ( Papio papio )
No full textABSTRACT Sleeping site selection in animals is thought to be influenced by multiple factors, including resource availability and competition, predation risk, thermoregulation and the risk of parasitic infection. While previous research has highlighted the importance of these factors, little is known about how they affect spatiotemporal patterns of sleeping site use among multiple groups of non‐territorial species with overlapping home ranges. Here, we investigated the sleeping site use of Guinea baboons ( Papio papio ) in Simenti, Senegal. We used locational data for 4 years of several baboon parties sharing the same range. We assessed the distribution of sleeping sites within the local habitat mosaic and patterns of sleeping site use of parties across time. We further investigated the proximity of sleeping sites of parties to those of co‐occurring parties and the impact of food availability and predator presence at the landscape level on the distance between parties' sleeping sites on the same night. In Simenti, Guinea baboons use trees exclusively as sleeping sites, and we found that the vast majority of sleeping sites were in the gallery forest along the perennial Gambia River, likely due to the availability of tall trees. Patterns of sleeping site use of individual parties in general showed no evidence of predator or parasite avoidance. Between parties, Guinea baboons slept in close spatial proximity (< 50 m) to at least one other party, regardless of food availability and predator presence. Thus, Guinea baboons in Simenti likely use the abundantly available sleeping sites opportunistically rather than being driven by intergroup competition or strategies for predator avoidance or reduction of the risk of parasite infection.Deutsche Forschungsgemeinschaft https://doi.org/10.13039/50110000165
Impact of food availability and predator presence on patterns of landscape partitioning among neighbouring Guinea baboon (Papio papio) parties
No full textAbstract Background Access to critical resources, including food, water, or shelter, significantly determines individual fitness. As these resources are limited in most habitats, animals may employ strategies of landscape partitioning to mitigate the impact of direct resource competition. Territoriality may be regarded as an aggressive form of landscape partitioning, but other forms of landscape partitioning exist in non-territorial species. Animals living in groups with greater flexibility in their association patterns, such as multilevel societies with fission–fusion dynamics, may adjust their grouping and space use patterns to short-term variations in ecological conditions such as food availability, predation pressure, or the presence of conspecific groups. This flexibility may allow them to balance the costs of competition while reaping the benefits of better predator detection and defence. Methods We explored patterns of landscape partitioning among neighbouring Guinea baboon (Papio papio) parties in the Niokolo-Koba National Park, Senegal. Guinea baboons live in a multilevel society in which parties predictably form higher-level associations (“gangs”). We used four years of locational data from individuals equipped with GPS collars to estimate annual home ranges, home range overlap, and average minimum distances between parties. We examined whether food availability and predator presence levels affected the cohesion between parties in 2022. Results We found substantial overlap in home range and core area among parties (33 to 100%). Food availability or predator presence did not affect the distance to the closest neighbouring party; the average minimum distance between parties was less than 100 m. Conclusions Our results suggest a low level of feeding competition between our study parties. Whether this is a general feature of Guinea baboons or particular to the situation in the Niokolo-Koba National Park remains to be investigated.Open-Access-Publikationsfonds 202
An examination of measures of young children's interest in natural object categories
No full textDevelopmental research utilizes various different methodologies and measures to study the
cognitive development of young children; however, the reliability and validity of such
measures have been a critical issue in all areas of research practices. To address this problem,
particularly in the area of research on infants’ interests, we examined the convergent validity
of previously reported measures of children’s interests in natural object categories, as indexed
by (1) parents’ estimation of their child’s interest in the categories, (2) extrinsic (overt choices
in a task), (3) intrinsic (looking time toward objects), and (4) physiological (pupil dilation)
responses to objects of different categories. Additionally, we also examined the discriminant
validity of all the aforementioned measures against the well-established and validated
measure of parents’ estimations of children’s vocabulary knowledge. Children completed two
tasks: (a) an eye-tracking task, where they were presented with images from a range of
defined categories, which collected indices of looking time and pupillary activity; (b) a
sticker-choice task, where they were asked to choose between two sticker-images from two
different categories belonging to the range of categories assessed in the previous task. Parents
completed two questionnaires to estimate (i) their child’s interests and (ii) vocabulary
knowledge in the categories presented. We first analyzed the discriminant validity between
the two parent measures, and found a significant positive association between them. Our
successive analyses showed no strong or significant associations between any of our
measures, apart from a significant positive association between children’s looking time and
parents’ estimations of children’s vocabulary knowledge. From our findings, we conclude that
measures of infants’ interests thus far may not have sufficient reliability to adequately capture
any potential relationship between these measures, or index different components of interest
in young children. We suggest next steps for further validation studies in infant research
Deep rooting revisited: Comparing the rooting patterns of European beech, Sessile oak, Scots pine, and Douglas fir in sandy soil to 3.8 m depth
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