Fig 1.
Satellite picture of a typical transect (St-Léonard as an example) surrounded by its arbitrarily defined buffer zone depicting study designs at the two scales considered. (A) Landscape scale with mapped habitat structures. (B) Field scale (B is an excerpt from A): parcels with bird observations depicted by stars (presence data) and parcels with absence of bird observations (pseudo-absence data). Reprinted from Swisstopo under a CC BY license, with permission from Alexandra Frank(see S1 File).
Table 1.
Explanatory variables recorded for habitat selection modelling.
Fig 2.
Model-averaged predictions of seasonal bird abundance at the landscape scale.
(A) Pooled species. (B) Turdus spp. (thrushes). (C) Fringillidae (finches). (D) Species richness. (E) Shannon diversity. These relationships demonstrate a significant (model-averaged) effect of cosmonth and/or sinmonth on habitat selection (see Table 3B). Shown are model-averaged bird density predictions (per 20 ha) from Poisson regression models with 95%-Bayesian credible intervals. The letters on the x-axis stand for the first letter of each month from J: January to D: December.
Table 2.
Competitive models from the overall and seasonal model selection procedures at both spatial scales.
Table 3.
Model-averaged parameter estimates.
Fig 3.
Model-averaged, seasonal relationships between grove cover and bird density at the landscape scale.
(A) Pooled species. (B) Turdus spp. (thrushes). (C) Species richness. (D) Shannon diversity index. The habitat preference for greater grove cover was dependent of season. The two months “June” and “December” were retained for plotting predictions because they reflect the greatest changes in habitat selection between summer and winter (extremes). Shown are model-averaged bird density predictions (per 20 ha) from Poisson regression models (overall habitat selection) with 95%-Bayesian credible intervals (delimited by grey areas). Predicted estimates were allowed to vary with the habitat variable under consideration, while other explanatory variables present in the average model were held constant at their mean values. Circles represent raw data of the entire year.
Fig 4.
Model-averaged predicted seasonal bird occurrence probability depending on green ground vegetation cover and month.
From (A) January to (L) December. Selection for green ground vegetation cover by pooled species significantly varied between seasons (months) at the field scale. 95%- Bayesian credible intervals are depicted by different coloured belts representing contrasting selection patterns. Circles represent raw data of the entire year. Occurrence probabilities greater than 0.5 indicate selection or preference whereas values lower than 0.5 should be interpreted as avoidance, relative to the other available habitats [56].
Fig 5.
Model-averaged predicted seasonal bird occurrence probability depending on brown ground vegetation cover and month.
(A) March. (B) June. (C) September. (D) December. Selection of brown ground vegetation cover by pooled species significantly varied between seasons (months) at the field scale. The four months were selected because they reflect the greatest changes in habitat selection along the annual cycle. 95%-Bayesian credible intervals are depicted by different coloured belts representing contrasted selection patterns. Circles represent raw data of the entire year. Occurrence probabilities greater than 0.5 indicate selection or preference whereas values lower than 0.5 should be interpreted as avoidance, relative to the other available habitats [56].
Fig 6.
Model-averaged predicted seasonal occurrence probability of thrushes depending on green ground vegetation cover and month.
(A) March. (B) June. (C) September. (D) December. Selection of green cover by thrushes significantly varied between seasons (months) at the field scale. The four months were selected because they reflect the greatest changes in habitat selection along the annual cycle. 95%-Bayesian credible intervals are depicted by different coloured belts representing contrasted selection patterns. Circles represent raw data of the entire year. Occurrence probabilities greater than 0.5 indicate selection or preference whereas values lower than 0.5 should be interpreted as avoidance, relative to the other available habitats [56].
Fig 7.
Model-averaged predicted overall occurrence probability of thrushes and finches depending on retained habitat variables.
(A) Turdus spp. (thrushes) with respect to distance to the nearest natural grassy area. Fringillidae (finches) in relation to (B) green and (C) brown vegetation covers. These habitat selection patterns at the field scale remained constant throughout the year. 95%-Bayesian credible intervals are drawn in grey. Circles represent raw data of the entire year. Occurrence probability was allowed to vary with the habitat variable under consideration, while other explanatory variables present in the average model were held constant at their mean values. Occurrence probabilities greater than 0.5 indicate selection or preference whereas values lower than 0.5 should be interpreted as avoidance, relative to the other available habitats [56].