Monitoring the feeding activity of nesting birds with an autonomous system: case study of the endangered Wryneck Jynx torquilla

This paper describes an original autonomous system based on the passive int egrated transponder (PIT) technology for monitoring the feeding activity of smalt birds at the nest. It is installed on pre-existing nestboxes which w ere slightly modified for the monitoring purposes. The system operates auto nomously for at least seven days and recorded data can be collected using a simple pocket calculator or a standard laptop computer, The monitoring cap abilities of the system include the arrival times of each adult, tagged wit h a PIT attached to one leg, and the regular collecting of microclimatic da ta. In the present study, the internal and external temperatures of the nes t were recorded. The autonomous system was validated during two weeks as pa rt of a more extended study on Wryneck Jynx torquilla L. foraging strategie s. Ifs efficacy was confirmed by comparison with conventional photographs o f birds at each feeding and climatic station data. The autonomous system al lows researchers to collect good quality and quantities of data with a mini mal disturbance of birds' behaviour Results obtained with this system show that brood size, temperature, precipitation and time of day influence the f eeding rate Of Wrynecks.