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Author Bugnyar, T.; Kotrschal, K. doi  openurl
  Title Leading a conspecific away from food in ravens ( Corvus corax)? Type Journal Article
  Year 2004 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 7 Issue 2 Pages 69-76  
  Keywords Misleading – Deception – Raven – Social foraging  
  Abstract Active misleading of conspecifics has been described as a social strategy mainly for primates. Here we report a raven leading a competitor away from food in a social foraging task. Four individuals had to search and compete for hidden food at color-marked clusters of artificial food caches. At the beginning of the experiment, a subordinate male found and exploited the majority of the food. As a result, the dominant male displaced him from the already opened boxes. The subordinate male then developed a pattern, when the loss of reward to the dominant got high, of moving to unrewarded clusters and opening boxes there. This diversion often led the dominant to approach those unrewarded clusters and the subordinate then had a head start for exploiting the rewarded boxes. Subsequently, however, the dominant male learned not to follow the subordinate to unrewarded clusters and eventually started searching for the reward himself. These interactions between the two males illustrate the ravens' potential for deceptively manipulating conspecifics. We discuss under which circumstances ravens might use this capacity.  
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  Notes Approved no  
  Call Number (up) Serial 2080  
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Author Bugnyar, T.; Kotrschal, K. doi  openurl
  Title Movement coordination and signalling in ravens (Corvus corax): an experimental field study Type Journal Article
  Year 2001 Publication Acta ethologica Abbreviated Journal Acta. Ethol.  
  Volume 3 Issue 2 Pages 101-109  
  Keywords Ravens – Corvus corax – Foraging – Coordination – Communication  
  Abstract Vagrant non-breeding ravens frequently attract conspecifics to rich ephemeral food sources. There, grouping may allow them to overcome the defence of territorial breeders. Here, we focus on ravens making use of regular food supplies in a game park, where they divert food from the provision of park animals. We investigated if ravens foraging in the Cumberland game park (Grünau, Austria) are attentive towards one another when they experience some unpredictability in food provisioning. We confronted a group of 30-50 ravens with two different treatments. Ten minutes ahead of the feeding of either wolves or wild boars we showed buckets containing pieces of meat to the ravens flying overhead. In the reliable cue treatment (RCT), the meat was placed next to one of the two enclosures, whereas in the unreliable cue treatment (UCT), the buckets were placed simultaneously in front of both enclosures though only in one of the enclosures were the animals fed 10 min later. Thus, during RCT but not during UCT, ravens could predict where food would become available. Only during UCT, ravens moved in large groups between the two feeding sites. Many ravens moving at the same time in the same direction may indicate some co-ordination in space and time, which is most likely achieved by social attraction among individuals. Furthermore, the number of ravens approaching and leaving, respectively, a feeding site cross-correlated with a temporary increase in the rate of a food-associated call, the yell. This suggests that in addition to watching each other, calling may have contributed to group formation. Possible benefits of group formation during food inspection are discussed.  
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  Notes Approved no  
  Call Number (up) Serial 2081  
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Author Janson, C.; Byrne, R. url  doi
openurl 
  Title What wild primates know about resources: opening up the black box Type Journal Article
  Year 2007 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 10 Issue 3 Pages 357-367  
  Keywords Cognitive map – Primate – Foraging – Ecology – Psychology  
  Abstract Abstract  We present the theoretical and practical difficulties of inferring the cognitive processes involved in spatial movement decisions of primates and other animals based on studies of their foraging behavior in the wild. Because the possible cognitive processes involved in foraging are not known a priori for a given species, some observed spatial movements could be consistent with a large number of processes ranging from simple undirected search processes to strategic goal-oriented travel. Two basic approaches can help to reveal the cognitive processes: (1) experiments designed to test specific mechanisms; (2) comparison of observed movements with predicted ones based on models of hypothesized foraging modes (ideally, quantitative ones). We describe how these two approaches have been applied to evidence for spatial knowledge of resources in primates, and for various hypothesized goals of spatial decisions in primates, reviewing what is now established. We conclude with a synthesis emphasizing what kinds of spatial movement data on unmanipulated primate populations in the wild are most useful in deciphering goal-oriented processes from random processes. Basic to all of these is an estimate of the animals ability to detect resources during search. Given knowledge of the animals detection ability, there are several observable patterns of resource use incompatible with a pure search process. These patterns include increasing movement speed when approaching versus leaving a resource, increasingly directed movement toward more valuable resources, and directed travel to distant resources from many starting locations. Thus, it should be possible to assess and compare spatial cognition across a variety of primate species and thus trace its ecological and evolutionary correlates.  
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  Notes Approved no  
  Call Number (up) Admin @ knut @ Serial 4214  
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Author Voelkl, B.; Huber, L. url  doi
openurl 
  Title Common marmosets (Callithrix jacchus) do not utilize social information in three simultaneous social foraging tasks Type Journal Article
  Year 2007 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 10 Issue 2 Pages 149-158  
  Keywords Marmosets – Social foraging – Social information – Food competition  
  Abstract Abstract  Social foraging is suggested to increase foraging efficiency, as individuals might benefit from public information acquired by monitoring the foraging activities of other group members. We conducted a series experiments with captive common marmosets (Callithrix jacchus) to investigate to what extent marmosets utilize social information about food location when foraging simultaneously with conspecifics. Subjects were confronted with dominant and subordinate demonstrators in three experiments which differed in the amount of information about food location available to the demonstrators. In all three experiments, the focal subjects` performance in the social condition was not enhanced in comparison to a non-social control condition. Because we could rule out kleptoparasitism and aggressive displacements as explanations, we argue that the subjects tendency for scramble competition by avoiding others and dispersing over the foraging area seems to inhibit or mask the acquisition of social information about the location of rewarded patches.  
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  Notes Approved no  
  Call Number (up) Admin @ knut @ Serial 4220  
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Author Goodwin, D.; Davidson, H.P.B.; Harris, P. url  doi
openurl 
  Title A note on behaviour of stabled horses with foraging devices in mangers and buckets Type Journal Article
  Year 2007 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.  
  Volume 105 Issue 1-3 Pages 238-243  
  Keywords Stabled horse; Behaviour; Foraging device; Management; Edinburgh foodball  
  Abstract Processed feed for stabled horses is usually presented in buckets or mangers, and is easily and rapidly consumed. Foraging devices based on the Edinburgh foodball can be used to provide part of the ration. Current designs are all placed on the floor, raising concerns regarding ingestion of foreign materials along with the dispensed food. Alternative devices were evaluated, when presented within suitable, clean containers to prolong food-handling times but avoid such issues. In four Latin square designed replicated trials we investigated behaviour of 12 stabled horses with three foraging devices. These were separately presented for 5 min, varied in sensory complexity (round, square, polyhedral) and contained 500 g high fibre pellets. In Trials 1 and 2 six geldings were presented with devices in buckets then mangers. All individuals foraged successfully from at least one device and behaviour was compared. However, all individuals exhibited some frustration while using the devices (either pawing or biting them). Horses frequently removed the devices from the buckets in Trial 1 terminating these sessions. In Trial 2 mean device foraging duration was ranked polyhedral > round > square. Mean pawing rate in Trial 2 was calculated for horses (frequency of pawing per individual/summed duration manipulation and foraging) and was highest with square (0.11, npawers = 6). In Trial 3 six stabled mares were presented with the same foraging devices in mangers. Mean foraging duration with devices again ranked polyhedral > round > square. Mean pawing rate was highest with round device (0.08, npawers = 4). Trial 4 investigated behaviour of six horses when devices initially containing five high fibre pellets became empty. Mean foraging duration with devices ranked round > polyhedral > square. Mean pawing rate was highest with square device (0.11, npawers = 4). All horses foraged successfully from at least one foraging device in buckets and mangers. Devices met initial objectives but the unpredictability of reward suggests a source of frustration and warrants further investigation.  
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  Notes Approved no  
  Call Number (up) Admin @ knut @ Serial 4345  
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Author Templeton, J.J.; Giraldeau, L.-A. url  doi
openurl 
  Title Vicarious sampling: the use of personal and public information by starlings foraging in a simple patchy environment Type Journal Article
  Year 1996 Publication Behavioral Ecology and Sociobiology Abbreviated Journal Behav. Ecol. Sociobiol.  
  Volume 38 Issue 2 Pages 105-114  
  Keywords Social foraging ? Patch sampling ? Public information ? Sturnidae  
  Abstract Group foragers may be able to assess patch quality more efficiently by paying attention to the sampling activities of conspecifics foraging in the same patch. In a previous field experiment, we showed that starlings foraging on patches of hidden food could use the successful foraging activities of others to help them assess patch quality. In order to determine whether a starling could also use another individual's lack of foraging success to assess and depart from empty patches more quickly, we carried out two experimental studies which compared the behaviour of captive starlings sampling artificial patches both when alone and when in pairs. Solitary starlings were first trained to assess patch quality in our experimental two-patch system, and were then tested on an empty patch both alone and with two types of partner bird. One partner sampled very few holes and thus provided a low amount of public information; the other sampled numerous holes and thus provided a high amount of public information. In experiment 1, we found no evidence of vicarious sampling. Subjects sampled a similar number of empty holes when alone as when with the low and high information partners; thus they continued to rely on their own personal information to make their patch departure decisions. In experiment 2, we modified the experimental patches, increasing the ease with which a bird could watch another's sampling activities, and increasing the difficulty of acquiring accurate personal sampling information. This time, subjects apparently did use public information, sampling fewer empty holes before departure when with the high-information partner than when with the low-information partner, and sampling fewer holes when with the low-information partner than when alone. We suggest that the degree to which personal and public information are used is likely to depend both on a forager's ability to remember where it has already sampled and on the type of environment in which foraging takes place.  
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  Notes Approved no  
  Call Number (up) Equine Behaviour @ team @ Serial 4198  
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Author Fleurance, G.; Duncan, P.; Fritz, H.; Cabaret, J.; Cortet, J.; Gordon, I.J. url  doi
openurl 
  Title Selection of feeding sites by horses at pasture: Testing the anti-parasite theory Type Journal Article
  Year 2007 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.  
  Volume 108 Issue 3-4 Pages 228-301  
  Keywords Foraging strategies; Horses; Parasite risk; Patch choice  
  Abstract Management of grazed grasslands for production and/or conservation objectives requires a thorough understanding of the choices of feeding sites by herbivores, and of the biological processes involved. Most models of the feeding strategies of herbivores are based on the principle that optimising the intake of energy (or some nutrient) is the primary goal of foragers but other selective forces, such as parasitism, could be important. Gastrointestinal parasites (including cyathostome nematodes) have powerful effects on the fitness of herbivores and may act as a major selection pressure favouring host behaviour that reduces the risk of encountering parasites. Among large herbivores, horses have perhaps the most marked tendency to select particular feeding sites within grasslands. We test here: (1) whether horses select feeding patches with relatively low parasite densities and (2) if their choice is affected by their parasite load. We used 10 two-year old saddle-horses and three periods. In the first period, the horses were under natural parasitism which varied strongly among individuals; in the second period they were all dewormed, and in the third, a sub-set of the horses was experimentally infected with cyathostome larvae. Ninety-eight percent of the infective larvae in the pasture were found <1 m from faeces. The main determinant of the choice of feeding patch by horses was the availability of patches of different parasite risk and grass height. Controlling for availability, the horses used tall grasses (>16 cm) less than expected, whether the grass was contaminated or not, and they selected for short patches >1 m from faeces, where the risk of encountering parasites was low. These results suggest that selection of feeding sites by horses is driven by an interaction between their nutritional and anti-parasite strategies: the horses avoid the patches of tall grass which are generally of low quality and areas contaminated by parasite larvae which leads them to prefer the patches of short grass far from faeces. The parasite status of the horses at the time of the experiment had no effect on their feeding choices. However, before concluding that the challenge by cyathostomes has no effect on the selection of feeding sites in horses, it will be necessary to test whether the history of parasitism of the individuals, rather than the current status, is important.  
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  Notes Approved no  
  Call Number (up) Equine Behaviour @ team @ Serial 4228  
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Author Valone, T.J. openurl 
  Title Group foraging, public information, and patch estimation Type Journal Article
  Year 1989 Publication Oikos Abbreviated Journal Oikos  
  Volume 56 Issue 3 Pages 357-363  
  Keywords Techniques; Mathematical techniques; Nutrition; Feeding behaviour; Behaviour; Social behaviour^, Comprehensive Zoology; Mathematical model; Resource patch estimation by group members; use of public information; Foraging; Group behaviour  
  Abstract Public information is information about the quality of a patch that can be obtained by observing the foraging success of other individuals in that patch. I examine the influence of the use of public information on patch departure and foraging efficiency of group members. When groups depart a patch with the first individual to leave, the use of public information can prevent the underutilization of resource patches.  
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  Notes Approved no  
  Call Number (up) Equine Behaviour @ team @ Serial 4274  
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Author Mech L.D. url  openurl
  Title Leadership in Wolf, Canis lupus, Packs. Type Journal Article
  Year 2000 Publication Canadian Field-Naturalist Abbreviated Journal Can Field Nat  
  Volume 114 Issue 2 Pages 259-263  
  Keywords Wolf, Canis lupus, leadership, behavior, foraging, movements, pup care, provisioning, sociality, reproduction, breeding, Northwest Territories.  
  Abstract I examine leadership in Wolf (Canis lupus) packs based on published observations and data gathered during summers from 1986 to 1998 studying a free-ranging pack of Wolves on Ellesmere Island that were habituated to my presence. The breeding male tended to initiate activities associated with foraging and travel, and the breeding female to initiate, and predominate in, pup care and protection. However, there was considerable overlap and interaction during these activities such that leadership could be considered a joint function. In packs with multiple breeders, quantitative information about leadership is needed.  
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  Notes Approved no  
  Call Number (up) Equine Behaviour @ team @ Serial 4688  
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Author Connor, R.C.; Mann, J.; Tyack, P.L.; Whitehead, H. url  doi
openurl 
  Title Social evolution in toothed whales Type Journal Article
  Year 1998 Publication Trends in Ecology & Evolution Abbreviated Journal Trends. Ecol. Evol  
  Volume 13 Issue 6 Pages 228-232  
  Keywords odontocetes; toothed whales; social evolution; communication; bottlenose dolphins; sperm whales; long-term studies; foraging  
  Abstract Two contrasting results emerge from comparisons of the social systems of several odontocetes with terrestrial mammals. Researchers have identified remarkable convergence in prominent features of the social systems of odontocetes such as the sperm whale and bottlenose dolphin with a few well-known terrestrial mammals such as the elephant and chimpanzee. In contrast, studies on killer whales and Baird's beaked whale reveal novel social solutions to aquatic living. The combination of convergent and novel features in odontocete social systems promise a more general understanding of the ecological determinants of social systems in both terrestrial and aquatic habitats, as well as the relationship between relative brain size and social evolution.  
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  Series Volume Series Issue Edition  
  ISSN 0169-5347 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number (up) Equine Behaviour @ team @ Serial 4789  
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