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 integrated transponder (PIT) technology for monitoring the feeding activity of smalt birds at the nest. It is installed on pre-existing nestboxes which were slightly modified for the monitoring purposes. The system operates autonomously for at least seven days and recorded data can be collected using a simple pocket calculator or a standard laptop computer, The monitoring capabilities of the system include the arrival times of each adult, tagged with a PIT attached to one leg, and the regular collecting of microclimatic data. In the present study, the internal and external temperatures of the nest were recorded. The autonomous system was validated during two weeks as part of a more extended study on Wryneck Jynx torquilla L. foraging strategies. Ifs efficacy was confirmed by comparison with conventional photographs of birds at each feeding and climatic station data. The autonomous system allows researchers to collect good quality and quantities of data with a minimal disturbance of birds' behaviour Results obtained with this system show that brood size, temperature, precipitation and time of day influence the feeding rate Of Wrynecks.