toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Schmidt, J.; Scheid, C.; Kotrschal, K.; Bugnyar, T.; Schloegl, C. url  doi
openurl 
  Title Gaze direction – A cue for hidden food in rooks (Corvus frugilegus)? Type Journal Article
  Year 2011 Publication Behavioural Processes Abbreviated Journal  
  Volume 88 Issue 2 Pages 88-93  
  Keywords Gaze; Object choice; Corvids; Effort; Rooks  
  Abstract Other individual's head- and eye-directions can be used as social cues indicating the presence of important events. Among birds, ravens and rooks have been shown to co-orient with conspecifics and with humans by following their gaze direction into distant space and behind visual screens. Both species use screens to cache food in private; also, it had been suggested that they may rely on gaze cues to detect hidden food. However, in an object-choice task, ravens failed to do so, and their competitive lifestyle may have prevented them from relying on these cues. Here we tested closely related and cooperative rooks. Food was hidden in one of two cups and the experimenter gazed at the baited cup. In a second experiment, we aimed to increase the birds’ motivation to choose correctly by increasing the investment needed to obtain the reward. To do so, the birds had to pull on a string to obtain the cup. Here, the birds as a group tended to rely on gaze cues. In addition, individual birds quickly learned to use the cue in both experiments. Although rooks may not use gaze cues to find hidden food spontaneously, they may quickly learn to do so.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0376-6357 ISBN Medium  
  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number Equine Behaviour @ team @ Serial 5420  
Permanent link to this record
 

 
Author Griffin, A.S.; Tebbich, S.; Bugnyar, T. url  doi
openurl 
  Title Animal cognition in a human-dominated world Type Journal Article
  Year 2017 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 20 Issue 1 Pages 1-6  
  Keywords  
  Abstract In the USA, each year, up to one billion birds are estimated to die from colliding with windowpanes (Sabo et al. 2016). A further 573,000 are struck down by wind turbines, along with 888,000 bats (Smallwood 2013). Worldwide, unintended capture in fishing devices is recognized as the single most serious global threat to migratory, long-lived marine taxa including turtles, birds, mammals and sharks (Wallace et al. 2013). Estimates put the number of amphibians killed per year on Australian roads at 5 million (Seiler 2003). The likelihood of a green turtle erroneously ingesting plastic debris, often by mistaking them for food, rose from 30% in 1985 to almost 50% in 2012 (Schuyler et al. 2013). Human-induced rapid environmental change (HIREC, sensu Sih et al. 2011) is filling animals’ environments with new threats which bear little or excessive similarity to those they have encountered in their evolutionary history (Dwernychuk and Boag 1972; Patten and Kelley 2010; Witherington 1997). As a consequence, many of the stimuli involved fall outside the adaptive processing space of animals’ evolutionary perceptual, learning, memory and decision-making systems, making individuals particularly vulnerable to their impact.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1435-9456 ISBN Medium  
  Area Expedition Conference  
  Notes (up) Approved no  
  Call Number Equine Behaviour @ team @ Griffin2017 Serial 6129  
Permanent link to this record
 

 
Author Bugnyar, T.; Stöwe, M.; Heinrich, B. doi  openurl
  Title Ravens, Corvus corax, follow gaze direction of humans around obstacles Type Journal Article
  Year 2004 Publication Proceedings of the Royal Society B: Biological Sciences Abbreviated Journal Proc. Roy. Soc. Lond. B Biol. Sci.  
  Volume 271 Issue 1546 Pages 1331-1336  
  Keywords  
  Abstract The ability to follow gaze (i.e. head and eye direction) has recently been shown for social mammals, particularly primates. In most studies, individuals could use gaze direction as a behavioural cue without understanding that the view of others may be different from their own. Here, we show that hand–raised ravens not only visually co–orient with the look–ups of a human experimenter but also reposition themselves to follow the experimenter's gaze around a visual barrier. Birds were capable of visual co–orientation already as fledglings but consistently tracked gaze direction behind obstacles not before six months of age. These results raise the possibility that sub–adult and adult ravens can project a line of sight for the other person into the distance. To what extent ravens may attribute mental significance to the visual behaviour of others is discussed.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes (up) 10.1098/rspb.2004.2738 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5009  
Permanent link to this record
 

 
Author Range, F.; Bugnyar, T.; Schlogl, C.; Kotrschal, K. doi  openurl
  Title Individual and sex differences in learning abilities of ravens Type Journal Article
  Year 2006 Publication Behavioural Processes Abbreviated Journal Behav. Process.  
  Volume 73 Issue 1 Pages 100-106  
  Keywords Animals; Behavior, Animal/*physiology; *Crows; Discrimination Learning/*physiology; Exploratory Behavior/physiology; Female; *Individuality; Male; Sex Factors; Spatial Behavior  
  Abstract Behavioral and physiological characteristics of individuals within the same species have been found to be stable across time and contexts. In this study, we investigated individual differences in learning abilities and object and social manipulation to test for consistency within individuals across different tasks. Individual ravens (Corvus corax) were tested in simple color and position discrimination tasks to establish their learning abilities. We found that males were significantly better in the acquisition of the first discrimination task and the object manipulation task, but not in any of the other tasks. Furthermore, faster learners engaged less often in manipulations of conspecifics and exploration of objects to get access to food. No relationship between object and social manipulation and reversal training were found. Our results suggest that individual differences in regard to the acquisition of new tasks may be related to personalities or at least object manipulation in ravens.  
  Address Konrad Lorenz Research Station, A-4645 Gruenau 11, Austria. friederike.range@univie.ac.at  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0376-6357 ISBN Medium  
  Area Expedition Conference  
  Notes (up) PMID:16675158 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4146  
Permanent link to this record
 

 
Author Bugnyar, T.; Heinrich, B. doi  openurl
  Title Pilfering ravens, Corvus corax, adjust their behaviour to social context and identity of competitors Type Journal Article
  Year 2006 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 9 Issue 4 Pages 369-376  
  Keywords Adaptation, Psychological; Animals; *Behavior, Animal; *Competitive Behavior; Crows/*physiology; *Deception; Feeding Behavior; Female; Male; Social Behavior; *Social Environment  
  Abstract Like other corvids, food-storing ravens protect their caches from being pilfered by conspecifics by means of aggression and by re-caching. In the wild and in captivity, potential pilferers rarely approach caches until the storers have left the cache vicinity. When storers are experimentally prevented from leaving, pilferers first search at places other than the cache sites. These behaviours raise the possibility that ravens are capable of withholding intentions and providing false information to avoid provoking the storers' aggression for cache protection. Alternatively, birds may refrain from pilfering to avoid conflicts with dominants. Here we examined whether ravens adjust their pilfer tactics according to social context and type of competitors. We allowed birds that had witnessed a conspecific making caches to pilfer those caches either in private, together with the storer, or together with a conspecific bystander that had not created the caches (non-storer) but had seen them being made. Compared to in-private trials, ravens delayed approaching the caches only in the presence of storers. Furthermore, they quickly engaged in searching away from the caches when together with dominant storers but directly approached the caches when together with dominant non-storers. These findings demonstrate that ravens selectively alter their pilfer behaviour with those individuals that are likely to defend the caches (storers) and support the interpretation that they are deceptively manipulating the others' behaviour.  
  Address Department of Biology, University of Vermont, Burlington, VT 05405, USA. thomas.bugnyar@univie.ac.at  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1435-9448 ISBN Medium  
  Area Expedition Conference  
  Notes (up) PMID:16909235 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2449  
Permanent link to this record
 

 
Author Heinrich, B.; Bugnyar, T. openurl 
  Title Just how smart are ravens? Type Journal Article
  Year 2007 Publication Scientific American Abbreviated Journal Sci Am  
  Volume 296 Issue 4 Pages 64-71  
  Keywords Animals; *Behavior, Animal; Crows/*physiology; Environment; *Intelligence; Predatory Behavior; Problem Solving; Thinking  
  Abstract  
  Address University of Vermont, USA  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0036-8733 ISBN Medium  
  Area Expedition Conference  
  Notes (up) PMID:17479632 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4101  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print