Sensory information and associative cues used in food detection by wild vervet monkeys.

Understanding animals' spatial perception is a critical step toward discerning their cognitive processes. The spatial sense is multimodal and based on both the external world and mental representations of that world. Navigation in each species depends upon its evolutionary history, physiology, and ecological niche. We carried out foraging experiments on wild vervet monkeys (Chlorocebus pygerythrus) at Lake Nabugabo, Uganda, to determine the types of cues used to detect food and whether associative cues could be used to find hidden food. Our first and second set of experiments differentiated between vervets' use of global spatial cues (including the arrangement of feeding platforms within the surrounding vegetation) and/or local layout cues (the position of platforms relative to one another), relative to the use of goal-object cues on each platform. Our third experiment provided an associative cue to the presence of food with global spatial, local layout, and goal-object cues disguised. Vervets located food above chance levels when goal-object cues and associative cues were present, and visual signals were the predominant goal-object cues that they attended to. With similar sample sizes and methods as previous studies on New World monkeys, vervets were not able to locate food using only global spatial cues and local layout cues, unlike all five species of platyrrhines thus far tested. Relative to these platyrrhines, the spatial location of food may need to stay the same for a longer time period before vervets encode this information, and goal-object cues may be more salient for them in small-scale space

Dispersal in male ursine colobus monkeys (Colobus vellerosus): Influence of age, rank and contact with other groups on dispersal decisions

Dispersal is male-biased in ursine colobus monkeys (Colobus vellerosus), although female dispersal also occurs (Teichroeb et al., 2009). Here we describe the process of male dispersal and its connection with between-group encounters (BGEs, N = 444) and male incursions (when males left their group and approached within 50 m of another group; N = 128) at the Boabeng-Fiema Monkey Sanctuary in central Ghana. Through BGEs and incursions, particularly those with non-aggressive interactions between individuals in different groups (BGEs, N = 17; incursions, N = 4), males could probably assess other groups for dispersal opportunities. There was a trend for males to perform incursions more frequently before emigrating voluntarily than involuntarily. Incursions were often performed towards the group that the male eventually transferred to. Incursions by alpha males were temporally shorter and more aggressive than those by non-alpha males. We suggest that non-alpha males used incursions to assess other groups for breeding or dispersal opportunities, whereas alpha males performed incursions mainly to convey information about their quality to neighbouring males and females. Male emigrations/disappearances (natal N = 20, secondary N = 43, unknown N = 9) and immigrations (N = 62) were recorded for seven groups during ten years (2000- 2010). Alpha males always emigrated involuntarily. Parallel emigration and immigration occurred. Males often immigrated into groups with a more favourable adult male/adult female ratio and improved their rank, both of which likely increased their mating opportunities. The most fitting ultimate explanation for both natal and secondary male dispersal in this population was the intrasexual competition for mates hypothesis, as males of all ages appeared to emigrate to improve their reproductive opportunities. © 2011 Koninklijke Brill NV, Leiden

Individualistic female dominance hierarchies with varying strength in a highly folivorous population of black-and-white colobus

Females that do not experience strong contest competition for food are presumed to form egalitarianâ relationships (i.e., lacking strong, linear dominance hierarchies). However, recent studies of Gorilla beringei beringei (mountain gorilla) have documented relatively strong, linear female dominance hierarchies despite them having a highly folivorous diet that generates relatively low levels of within-group contest competition (Robbins et al., 2005, 2007). To investigate if this pattern holds true for other highly folivorous species that may experience low levels of contest competition, we examined the linearity and strength of female dominance hierarchies in a population of Colobus vellerosus (ursine colobus or white-thighed colobus) at Boabeng-Fiema, Ghana. From 2004 to 2011, we collected data via ad libitum and focal sampling of 75 adult and subadult females in eight groups. Half of the study groups had few unknown submissive relationships, and females formed individualistic hierarchies with high linearity indices ranging from 0.9 to 1. There was between-group variation in all components of hierarchical strength (i.e., hierarchical expression, consistency, and stability). Groups showed varying rates of submission, and there was a short latency to detect a linear hierarchy in some groups and a long latency in other groups (i.e., varying levels of hierarchical expression). Females in most groups formed unidirectional and stable relationships. Maturing females challenged older females in some groups, and these groups had more non-linear relationships (i.e., dyads with more submissive interactions down rather than up the hierarchy) and higher rates of individual rank change than other groups. Based on low rates of submission, long latencies, and/or some inconsistencies, we conclude that most groups form relatively weak dominance hierarchies, similar to other egalitarian primates. However, a few groups formed strong dominance hierarchies, similar to some despotic primates. Colobus vellerosus occasionally forage on contestable food items, and this may provide enough incentive for females to establish individualistic dominance hierarchies of varying strength. © 2013 Koninklijke Brill NV, Leiden, The Netherlands

Factors influencing male affiliation and coalitions in a species with male dispersal and intense male-male competition, Colobus vellerosus

Male Colobus vellerosus compete intensely for access to females, which sometimes leads to mortal wounding. Yet, males often form cooperative relationships to overtake prime-aged males and immigrate into bisexual groups. We investigated the factors that predicted the presence of coalitions and affiliative relationships among males in this species. Interactions among males in 292 dyads from six groups were examined from 2004 to 2010 at Boabeng-Fiema, Ghana. Affiliation rates among males were higher and aggression rates lower when one or both males in the dyad were subadult, compared to adult male dyads. Affiliation rates tended to be higher among males that were kin but no other aspect of male relationships predicted affiliation. Coalitions among males were rarely observed and primarily occurred in the context of joint defense against extra-group males (93.5% of events). Adult males were more likely to provide coalitionary support than subadults and coalitions occurred significantly more often when both males were high ranking, since these males probably benefited most in terms of reproductive success from excluding extra-group males. Rank-changing and leveling coalitions among low-ranking males appear to be quite rare or absent in C. vellerosus. The costs of these types of coalitions may be too high or male group size too small on average for these types of coalitions to have been selected for. The overall low rates of affiliation and coalitions among male C. vellerosus are likely influenced by male-biased dispersal and the high level of male–male competition.</jats:p

Crop raiding patterns of solitary and social groups of red-tailed monkeys on cocoa pods in Uganda

Crop damage by wildlife is a very prevalent form of human-wildlife conflict adjacent to protected areas, and great economic losses from crop raiding impede efforts to protect wildlife. Management plans are needed to decrease damage by raiding wildlife, yet conservation biologists typically lack the basic information needed for informed conservation strategies. Red-tailed monkeys (Cercopithecus ascanius) raid a variety of crops adjacent to protected forests in East Africa; however, the role of group structure on crop raiding has not been explored. Here, crop raiding patterns of solitary males and social groups were investigated during 10 months in a plantation of mature cocoa in Uganda. Monkeys gained access to the plantation via trees planted as wind breaks and shade trees, and the sighting frequency of groups was negatively related to the distance from the forest edge. In contrast, solitary males were sighted more frequently far from the forest edge and caused proportionately greater damage than members raiding in a social group. These results highlight that for social animals, crop raiding behavior can vary among types of social groupings; appropriate strategies to cope with raiding must therefore respond to this variation. Deborah Baranga, G. Isabirye Basuta, Julie A. Teichroeb, and Colin A. Chapman

Emergent group level navigation: an agent-based evaluation of movement patterns in a folivorous primate.

The foraging activity of many organisms reveal strategic movement patterns, showing efficient use of spatially distributed resources. The underlying mechanisms behind these movement patterns, such as the use of spatial memory, are topics of considerable debate. To augment existing evidence of spatial memory use in primates, we generated movement patterns from simulated primate agents with simple sensory and behavioral capabilities. We developed agents representing various hypotheses of memory use, and compared the movement patterns of simulated groups to those of an observed group of red colobus monkeys (Procolobus rufomitratus), testing for: the effects of memory type (Euclidian or landmark based), amount of memory retention, and the effects of social rules in making foraging choices at the scale of the group (independent or leader led). Our results indicate that red colobus movement patterns fit best with simulated groups that have landmark based memory and a follow the leader foraging strategy. Comparisons between simulated agents revealed that social rules had the greatest impact on a group's step length, whereas the type of memory had the highest impact on a group's path tortuosity and cohesion. Using simulation studies as experimental trials to test theories of spatial memory use allows the development of insight into the behavioral mechanisms behind animal movement, developing case-specific results, as well as general results informing how changes to perception and behavior influence movement patterns

Methodological suggestions for inferring fear from vigilance

I suggest some methods for data-collection and analysis that may help researchers infer fear from vigilance

EFFECTS OF EMBRYONIC EXPOSURE TO PREDATOR CUES ON PRE- AND POST-HATCHING ANTIPREDATOR BEHAVIOUR IN COMMON CUTTLEFISH (SEPIA OFFICINALIS)

Since neonates are often the age-class most susceptible to predation, there should be strong selective pressure on prey for the early development of successful antipredator behaviour. The ability to assess predation risk as early as the embryonic stages may increase an individual’s survival, as it would allow young individuals to be better adapted to current predation risk, since present conditions are often a good short-term indicator of future conditions. I exposed embryonic cuttlefish (Sepia officinalis) to the odour of a predator and tested both the responses of the embryos to this stimulus, and the latent effects of both long (approximately 3 weeks)- and short (a few days)- exposure on the behaviour of newly-hatched juveniles, in particular the efficiency of cryptic behaviour on uniform and sandy substrates. Exposure to novel odours, whether they were predators or non-predators, increased the ventilation rate of embryos. This may be adaptive, because it helps an individual survive first encounters with unknown potential dangers before they have opportunity to collect information about a novel stimulus. Long-term exposure to predator odour increased the camouflage efficiencies of juveniles on uniform substrates. On sandy substrate, the exposure did not affect camouflage, but increased the extent of sand digging behaviour. Juveniles were also larger in size at hatching when exposed to predators compared to those that were not. These results were not seen in individuals with only short-term exposure to predator. Short-term exposure also had no effect on camouflage efficiencies on uniform or sandy substrates, or on sand digging behaviour. The results of my thesis indicate that high predation risk during embryonic development induces behavioural and morphological changes in camouflage expression and body size in cuttlefish hatchlings. The behavioural plasticity may provide survival benefits for newly hatched individuals, but may come at a cost in terms of body size. Such behavioural and morphological plasticity may have an impact on predator-prey dynamics and organization of communities

Norwegian Attitudes Toward Non-native English Speakers and Accents

I denne studien benyttes to ulike metoder for å svare på følgende forskningsspørsmål: 1) Hva er nordmenns holdninger til ulike utenlandske engelske aksenter og språkbrukere, og 2) er det en sammenheng mellom stereotypier om ulike nasjonaliteter og nordmenns holdninger til utenlandske engelske aksenter? Den første metoden som blir brukt er en indirekte metode som heter «verbal guise test», en type spørreundersøkelse der 51 nordmenn har evaluert lydopptak av fire ulike utenlandske engelske aksenter. Aksentene som ble evaluert er en tysk aksent, fransk aksent, russisk aksent og hindi aksent. Den andre metoden som blir benyttet er kvalitative intervjuer av utenlandske utvekslingsstudenter i Norge. Disse er utenlandske engelskbrukere i Norge, og disse intervjuene kan derfor gi et innblikk i nordmenns holdninger til utenlandske engelsk aksenter. Gjennom intervjuene deler informantene deres erfaringer med å være utenlandske engelskbrukere i Norge og deres tanker rundt nordmenns holdninger til ulike utenlandske engelsk aksenter. Informantene har aksenter som samsvarer med aksentene i spørreundersøkelsen. Hovedfunnene i studien er at Nordmenn rangerer vest-europeiske engelske aksenter som tysk og fransk høyere når det gjelder sosio-intelektuell status, enn andre utenlandske engelske aksenter. Videre viser funnene at den russiske aksenten evalueres negativt sammenlignet med de andre aksentene, og at den franske aksenten appellerer mer til nordmenn når det gjelder estetisk kvalitet.This master’s thesis employs two sets of data to answer the following research questions: 1) What are Norwegian attitudes toward non-native English speakers and their accents and 2) Are there links between stereotypes/prejudices against certain nationalities and Norwegian attitudes toward non-native English speakers and accents? The first method used to assess these questions is an indirect method called a verbal guise test - executed as an online questionnaire in this study. 51 Norwegian university and college students responded to this questionnaire, evaluating four speech samples of different non-native English accents based on how they thought the speaker sounded. The speech samples included are recordings of a German, a French, a Hindi and a Russian speaker. These four non-native speakers were evaluated on 12 semantic differential items using a 7-point scale. These 12 items represented the following three factors: socio-intellectual status, aesthetic quality, and dynamism. In order to gain further insight into Norwegian attitudes, four non-native English speakers studying in Norway (who are not Norwegian) were interviewed. The qualitative data collected through these interviews are included in this thesis to provide insight into the experiences of non-native English speakers living in Norway. Specifically, they provide insight into Norwegian attitudes toward non-native English speakers and their accents. Importantly, the qualitative data is used to clarify findings from the verbal guise test. Similarities between the two datasets are drawn on to develop the discussion of Norwegian attitudes. The main findings of this study are that western European non-native accents such as German and French are rated and perceived higher in terms of socio-intellectual status than other non-native English accents and speakers. Specifically, that the Russian speech sample is evaluated quite negatively in comparison to the other speech samples. Another main finding is that Norwegians rate and perceive the French accent and French people higher in terms of aesthetic quality and attractiveness