Using ring records and field surveys to predict the winter distribution of a migratory passerine

Abstract

Capsule Ring records can be used to predict spatial changes in habitat suitability in wintering grounds of migratory birds as shown by a case study with the Meadow Pipit (Anthus pratensis). Aims To forecast the winter distribution of the Meadow Pipit in the Iberian Peninsula and the Maghreb (1 700 000 km 2) by combining ring records and fields surveys. Methods We processed winter ring records with Maxent, a popular machine-learning technique used to predict the occurrence probability of species. We then tested whether the occurrence probabilities predicted by the model were significantly positively related to the actual abundance of the Pipit in Spain and Morocco. Results Occurrence probabilities provided by Maxent explained 6% of Pipit abundance distribution in partial least squares regression analyses. There was, in addition, a weak effect of geographical location (1.5%) and a strong effect of local vegetation (17.6%) on Pipit distribution. The occurrence probabilities were used to classify the winter range of the Meadow Pipit in sectors of high, medium and low suitability. The most suitable sector occupied 9% of the region (153 000 km 2) and was restricted to warm and moist lowlands where Pipits gather in grasslands. Conclusion These results support the potential usefulness of cartographic models derived from ring records to describe the wintering range of migratory birds.

Range compression of migratory passerines in wintering grounds of the Western Mediterranean: conservation prospects

“…The potential wintering range of migratory passerines depicted a homogeneous pattern, with most birds constrained to similar lowlands and coastal sectors of the Iberian Peninsula and the Maghreb (Figure S2-2, Figure 1), where wood cover was positively (thrushes) or negatively (the rest of species) correlated, supporting the effect of specific habitat preferences on bird distribution (see Tellería et al 1999, del Moral et al 2012). These patterns are similar to the wintering maps reported by ring modelling of Meadow Pipit Anthus pratensis , Chiffchaffs Phylloscopus collybita , Blackcaps Sylvia atricapilla and Robin Erithacus rubecula , validated by field sampling of abundances (Tellería et al 2012, 2014a, 2016).…”

“…In this case, range contraction was explained by the sharp reduction of emerged lands available to birds in the Mesoamerican corridor (Mills 2006). We suspect a similar effect in the south-western border of the Palaearctic, where migratory populations are restricted to a minor part of emerged lands (mean range covers 16% of the Iberian Peninsula and the Maghreb) because suitable areas are constrained by coastlines, cold highlands and the dry expanses of the Sahara (Tellería et al 2014a,b).…”

“…Thus, it is interesting to explore whether seasonal changes in the range size of migratory populations reveal the existence of small areas of particular conservation concern. It has been shown that the western Mediterranean Basin is not a homogeneous wintering ground since the best areas are mainly restricted to mild lowlands and coastal areas (Tellería et al 1999, 2014a, Carrascal et al 2012). However, we do not know if these geographical features reduce the wintering range of migratory populations compared to their breeding grounds in central Europe.…”

Effect of Climate Change on Mediterranean Winter Ranges of Two Migratory Passerines

“…This trait is interesting from a methodological point of view because it will attenuate the confounding effects of local conspecifics on the abundance patterning of migratory individuals [ 48 ]. In this way, predictions based on ring recoveries in wintering grounds can be validated by the abundance distribution of the same migratory populations [ 49 ]. Second, pipits and chiffchaffs are small insectivorous passerines that occur in a broad range of habitats [ 42 , 43 ].…”

“…The resulting ranges were used to define maps of low, medium and high climate suitability for each species. The line transects were distributed within these sectors to test with χ 2 or ANOVA analyses if the number of localities at which the species are found to occur (occupancy) [ 32 ] and mean abundance increased from low to high climate-suitable sectors [ 49 ]. In addition, since the distribution models were launched to predict climate suitability, the effect of habitat structure on bird distribution was controlled by selecting the habitats mainly used by pipits (grasslands, farmlands, wooded pasturelands; n = 375) and chiffchaffs (wooded pasturelands, farmlands, scrublands, woodlands; n = 320) according to current information on winter habitat preferences [ 45 , 47 ].…”