Habitat selection and interspecific competition between Sylvia warblers in Cyprus following the rapid expansion of a recent colonizer

Abstract

Many island endemics around the world have evolved from populations of colonists. Further colonizations may lead to interactions between older and newer colonists. Little is known, however, regarding the impact of more recent island colonizers on incumbent congeners, partly because of a dearth of examples of natural colonizations in the recent past. Sardinian Warbler (Sylvia melanocephala) recently colonized Cyprus and has rapidly expanded its breeding range. We examined the impact of the Sardinian Warbler colonization on the endemic Cyprus Warbler (S. melanothorax) and on another congener, the Spectacled Warbler (S. conspicillata). We performed 402 population surveys in 32 sample plots across the island, covering five different habitat types and variation across three seasons. Our results show that Cyprus Warbler has undergone a significant decline during the five years of the study, especially in disturbed habitats, while Sardinian and Spectacled Warbler populations have remained stable. Although the longer established Spectacled Warbler clearly segregated habitat with Cyprus Warbler, Sardinian Warbler numbers were negatively associated with Cyprus Warbler abundance, suggesting its presence may contribute to the endemic's decline. Maquis scrub was favored by both Cyprus Warbler and Sardinian Warbler, but the latter also occurred in high densities in disturbed habitats. The colonizer's prevalence in disturbed, mixed habitat, suggests it may replace the endemic in parts of its former range following anthropogenic perturbations. Natural colonizations may contribute to rapid population declines in island endemics in a similar way to introduced species, especially when combined with strong effects of habitat disturbance. Sélection de l'habitat et compétition interspécifique entre les fauvettes des jardins à Chypre à la suite de l'expansion rapide d'une espèce colonisatrice récente RÉSUMÉ. De nombreuses espèces endémiques des îles du monde entier ont évolué à partir de populations colonisatrices. De nouvelles colonisations peuvent ensuite donner lieu à des interactions entre les populations récentes et plus anciennes. On en sait peu, en revanche, au sujet de l'impact des colonisateurs les plus récents des îles sur leurs congénères déjà présents, en partie en raison de la rareté des exemples de colonisations naturelles dans un passé récent. La fauvette mélanocéphale (Sylvia melanocephala) a récemment colonisé Chypre et son territoire de reproduction s'est rapidement développé. Nous avons examiné l'impact de la colonisation de fauvettes mélanocéphales sur l'espèce endémique, la fauvette de Chypre (S. melanothorax) ainsi que sur un autre congénère, la fauvette à lunettes (S. conspicillata). Nous avons réalisé 402 enquêtes sur ces populations sur 32 territoires échantillons dans l'île, couvrant cinq types d'habitats et les variations au cours de trois saisons. Nos résultats indiquent que la fauvette de Chypre a connu un déclin important au cours des cinq dernières années de l'étude, en particulier dans les habitats pertu...

Genomic data reveal contrasting patterns of divergence among island and mainland birds of the Eastern Mediterranean

“…Indeed, population structure between Sardinian Warbler in Cyprus and the mainland was a surprising result, because it only recently colonized the island (Frost 1995, Hellicar & Kirschel 2021, Papanikolas et al . 2021), and we expect that sampling in neighbouring continental populations of Cyprus might reveal little differentiation of the Cyprus population from them and more of a pattern of IBD.…”

Accelerated avian invasion into the Mediterranean region endangers biodiversity and mandates international collaboration

“…Islands tend to be characterized by high endemism but lower overall species richness and often more vulnerable incumbents than their mainland counterparts (Clavero et al, 2009). While common myna has not yet invaded Cyprus, 1 the rapid spread within the last couple of decades across the island of a recent colonizer (Sardinian warbler Sylvia melanocephala ) with parallel decline in the endemic Cyprus warbler S. melanothorax (Papanikolas et al, 2021), and expansion of the introduced laughing dove Streptopelia senegalensis within the last decade (ANGK, pers. obs.…”

Breeding habitat selection of three sympatric species of Mediterranean warblers in eastern Spain

“…6,7,10 In addition, differences in habitat selection between migrant and sedentary species were also evaluated. 5,9,11 Other studies on the habitat selection dynamics of warblers considered factors such as anthropic disturbance, 19 seasonality 20 and social behaviour. 21 Finally, Coreau & Martin 22 performed a multiscale analysis in order to improve the knowledge about bird distribution and changes in their habitat selection.…”