Measuring Behavior 2005: Decker

Measuring the behavior of mink with permanent access to running wheels: The design of the wheels and a description of the digital video system

E.L. Decker

Department of Animal Health, Welfare and Nutrition, Danish Institute of Agricultural Sciences, Denmark

In order to quantify the activity level of mink in different farming systems 32 running wheels equipped with magnetic switches, were installed on alternate cages in a group of 64 cages.

The mink had permanent access to the wheels. As the wheels were designed so that they always returned to a position with the magnet on the opposite side of the switch, mink entering the wheel had to make at least half a turn for movement to be registered, making certain that we measured full revolutions.

The switches were connected to a digital IO card in a PC. All signals from the switches were timestamped and registered in a file.

The PC was also equipped with AD video cards for 8 video cameras. Moving the cameras every day gave us 24h video for each cage, every 8th day.

The programme collecting the video is a ‘standard’ security system from MSH-video (M. Shafro&Co) in Latvia. It is a Client-Server system with everything necessary for surveillance: reduced frame rate for ‘time lapse’ video, software motion detectors (motion intensity and area can be defined) for each camera. What is not standard about the system is that it saves all the video in a database instead of in a .mpg .le, allowing full control of the recorded video with features such as a timeline for all cameras showing detected motion, spooling, cutting, the possibility for scanning with a predefined time span, conversion to standard .mpg for automatic analysis and, most important for analysing video, registering and timestamping (video time of course!) all keypresses while viewing the video.

A paper discussing the results will be published by S.W. Hansen from DIAS. Just one result for the technically minded: make sure to put good bearings in the wheels, some mink ran up to 17000 revolutions a day (about 25 km).

Paper presented at Measuring Behavior 2005 , 5^th International Conference on Methods and Techniques in Behavioral Research, 30 August - 2 September 2005, Wageningen, The Netherlands.