Influence of researcher experience and fieldwork intensity on the probability of brood losses in sensitive species: The case of the Red-backed Shrike Lanius collurio

Abstract

Minimizing disturbance to animals when studying them should be a major consideration in ecological research design, especially when species are known to be sensitive to disturbances. A basic method in the study of bird reproductive ecology involves nest visits, but these can adversely affect birds’ breeding success. Appropriate fieldwork procedures are therefore highly important, especially in the case of timid and sensitive species. This study aimed to assess the impact of the method of searching for nests of Red-backed Shrike Lanius collurio on the probability of these birds abandoning their broods. Our study revealed that observer experience and nest searching intensity did influence the likelihood of brood desertion by this species. Less field experience and a greater nest searching intensity caused the shrikes to abandon their nests more often. We recommend paying scrupulous attention to the behaviour of the birds when searching for nests and when looking for nests after incubation has started.