Fig 1.
Map of the study area, represented in a section of the province of Toledo, central Spain.
Green area delimits the Province of Toledo. The red dot in the map of Spain represents the location of the study site, and the red areas in the general view of the study site describe the two census areas (TR13-Villarrubia de Santiago and TR14-Santa Cruz de la Zarza). The picture images represent the two distinct census areas in higher detail. The pink lines in the images represent the transects by the rail and the blue lines represent transects 500m from the rail. Note that, for schematic purposes and visibility in the figure, transects by the rail were drawn slightly separated from the railway line, but they were performed very close to it, in reality. The black line crossing the census areas and going across the general map of Spain represents the High-Speed Railway Madrid—Castilla La Mancha—Comunidad Valenciana line. Reprinted from ign.es under a CC BY 4.0 license, with permission from IGN (Spanish National Geographic Institute), original copyright PNOAHISTORICO 2004–2019, scne.es.
Fig 2.
Variation in the number of birds observed in relation to the distance to rail.
A. Estimated mean number of Small Bird individuals observed in relation to the distance to the railway. A two level factor was considered for the distance to rail: Rail (area immediately adjancent to the HSR infrastructure) and 500m (area 500m away from the HSR infrastructure). Vertical lines indicate 95% confidence intervals. B. Estimated mean number of Large Bird individuals observed in relation to the distance to the railway. A continuous scale of distance to rail expressed in km was considered in this case. Grey shaded area represents 95% confidence intervals.
Fig 3.
Variation in the number of birds observed in relation to season and year.
A. Estimated mean numer of Small Bird individuals observed in relation to season (Autumn, Spring, Summer and Winter) and year of surveys (First: 2014–2015, Second: 2018–2019). The vertical lines represent 95% confidence intervals. B. Estimated mean number of Large Bird individuals observed in relation to season (Autumn, Spring, Summer and Winter) and year of surveys (First: 2014–2015, Second: 2018–2019). The vertical lines represent 95% confidence intervals.
Table 1.
Predictors of effect of different factors on number of birds per transect and species.
Fig 4.
Multivariate analysis plots of enviromental factors in relation to different bird species.
A. Ordination diagram of Redundancy Analysis (RDA). The most common species of Small Birds detected in the areas of survey are represented, along with blue arrows representing the environmental variables. The length of the arrows represents the relative weight of the variable in explaining the variance in the bird community. Species names are abbreviated by showing the first three letters of the genus and specific names separated by a point. B. Ordination diagram of Canonical Correspondence Analysis (CCA). The most common species of Large Birds detected in the areas of survey are represented, along with blue arrows representing the environmental variables. The length of the arrows represents the relative weight of the variable in explaining the variance in the bird community. Species names are abbreviated by showing the first three letters of the genus and specific names separated by a point.
Table 2.
Variance in the community of birds surrounding the HSR explained by different environmental variables.
Fig 5.
Diagram of pairwise dissimilarity matrix for Small Birds.
Diagram expresses the difference in species composition between different areas of survey. The railway infrastructure is represented at the bottom. Transects belonging to the areas of surveys (Santa Cruz de la Zarza and Villarubia de Santiago) are represented using two different colours. The vertical axis represents distance to the rail (Rail and 500m). Numbers show the results given by the Jaccard dissimilarity index, expressing how different are the communities in each of the areas compared.