Collaboration: Behavioural Biologist Prof. dr. A.G.G. Ton Groothuis from the Faculty of Science and Engineering, Institute for Evolutionary Life Sciences, Groningen
In winter 2016-2017 I started a pilot project in collaboration with Behavioural Biologist Prof. dr. A.G.G.Ton Groothuis. We want to investigate if certain Great Grey Shrikes (Lanius excubitor) have there own personality and preference for the way they fix their prey and how these activities are lateralized (asymmetrical in terms of preference for leg and eye).
Lateralization of brain and behavior and personality are properties that until recently were seen as unique to humans. Recently research has indicated that both of them, however, have a fundamental property in the organization of brain and behaviour of animals and possible interrelation. Man seems almost unique in that on population level. There is a vast majority that is lateralized in the same direction, such as right handed. One of the evolutionary explanations is that the degree of population bias in lateralization positive linked to the frequency of tool use. The Great Grey Shrike is a species of bird that captures large animal preys and caches them by impaling or wedging them to objects in the environment.
In the Laniidae, vertebrate prey is impaled on sharp objects, decapitated and, in most cases, the brain consumed before other body parts (Reuven Yosef, unpublished data). Impaling is defined as the skewering of prey on a sharp projection; “wedging” is the placing of the item in the fork of a substrate (branch, barbed wire, etc.) that allows the predator to manipulate and feed on a prey item. In some cases, while the predator attempts to wedge the prey it may be accidentally impaled on a sharp projection, but intentional and systematic impaling, as it occurs in the true shrikes has not been documented in any non-Laniidaen bird species. Both wedging and impaling are considered tools that facilitate dismemberment of prey at lower energetic costs to the predator ( Schon, 1994; Cade, 1995, R. Yosef, B. Pinshow, 2005).
The aim of the project is to see (1) to what extent this behavior is lateralized on an individual level, (2) on population level (3) and how it is linked to personality properties. Next winter (2017-2018) we will officially start the project.
more information about impaling in true shrikes (Laniidae):
Made possible by financial support from the Foundation Lucie Burgers for Comparative Behaviour Research, Arnhem