Railways as a potential bird census tool in citizen-science projects: a preliminary study

Abstract

ABSTRACTCapsule: Bird surveys carried out during a railway journey capture a significant proportion of the species and individuals recorded through line transects (LT).Aims: To explore the suitability of railways as a bird census tool in a scenario where bird data massively recorded by passengers of the railway network could be collected through appropriate web portals and cell phone technologies.Methods: Railway and walked transects were conducted along the 40 km rail line connecting the towns of Valencia and Buñol, Spain. From June 2012 to May 2016, I carried out a weekly survey of birds from the railway line looking through the train window. Additionally, to assess the efficacy of train surveys, a railway section 11 km long was surveyed monthly on foot from December 2014 to November 2015.Results: Train surveys were unsuitable to detect many woodland birds but were relatively efficient in detecting raptors, open-field and aquatic bird species. About 75% of non-woodland species were detected from the train, and there was a positive correlation between counts obtained through train and LT; mean detection rate per species was between 50% and 80% depending on the season. Overall, larger and numerically more important species were better quantified. Further, detection rates of several medium-large species were greater than one, indicating a superior efficiency of train over LT. Only for nine species were data sufficient to calculate population trends, which in several cases were similar to those obtained through monitoring programmes operating at coarser spatial scales.Conclusions: The relatively high performance of the method and the fact that broad geographical areas could be easily surveyed (even on a daily basis) by many people in a relatively short time make railway-based bird surveys a candidate to be used in citizen science programmes.