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Population divergence could be strongly affected by species ecology and might not be a direct response to climate‐driven environmental change. We tested this in the middle spotted woodpecker (Dendrocoptes medius), a non‐migratory, low‐dispersal habitat specialist associated with old deciduous forests of the Western Palearctic. We present the first phylogeographic study of this species integrating genetic data (three mitochondrial loci, one autosomal and one Z‐linked intron) with species distribution modelling. Based on this species ecology, we predicted that the middle spotted woodpecker could have colonized its current range from multiple Last Glacial Maximum (LGM) refugia and that strongly structured populations could be expected. Indeed, we discovered a strong genetic divergence between Asian and European populations, with a split estimated at around one million of years ago. This was surprising given only slight intraspecific variation in plumage and morphology. Although there was no significant phylogeographic structure within the Asian and European groups, we cannot exclude the possibility of multiple refugia within either group during the LGM. This has to be further investigated with more extensive geographic sampling and larger number of variable independently evolving markers. Future studies should also investigate potential differences in vocalizations and ecology between the two groups. Lineages showing similar level of genetic differentiation including woodpeckers are often treated as species‐level taxa. Comparison of our results with the phylogeographic history of other woodpeckers, suggests that sympatric species with similar life‐histories might have idiosyncratic phylogeographic patterns probably resulting from different ecological requirements or historic stochasticity.

I investigated sexual differences in morphology and foraging behaviour in the nearly monomorphic Middle Spotted Woodpecker Dendrocopos medius. In the northeastern Swiss lowlands, radiotracked birds were observed from 1994 to 1996 between January and June. The sexes overlapped in all morphological characters, with males (n = 25) being on average larger than females (n = 17). Bill-length and length of the crimson-red crown patch were most useful to discriminate the sexes. Sex-specific differences in foraging behaviour were found both within and between the prebreeding and breeding periods concerning the use of tree species, foraging techniques, relative height zones and living and dead substrates within a tree. Overall, both sexes had broader niches in the prebreeding than in the breeding period and niche overlap was larger during the latter period. Hence, sex-specific differences were more pronounced in the prebreeding than in the breeding period, indicating different niche use of males and females in the two periods. These varying patterns of sex-specific differences imply that niche segregation results from behavioural plasticity, probably based on dominance relationships between the sexes, rather than from sexual dimorphism.

Twelve polymorphic microsatellite loci were developed for Dendrocopos medius. Polymorphism was assessed for 27 individuals from the southwesternmost population of this woodpecker species. The number of alleles per locus ranged from three to seven, with observed heterozygosity values from 0.444 to 0.852. Genotypic frequencies conformed to Hardy–Weinberg equilibrium, and no evidence for linkage disequilibrium was observed. Multilocus genotypes resulting from this set of markers will be useful to determine genetic diversity and differentiation within and among habitat patches inhabited by D. medius. Three of the loci were polymorphic for Picoides articus.

Food composition, prey size utilization and foraging behaviour of three sympatric woodpecker species (Dendrocopos major, D. medius, D. minor) were studied in an oak forest near Budapest during the breeding season in 1983 and 1984. Considering these three aspects of feeding, the great spotted woodpecker is a generalist species. Food composition of this species resembled the arthropod supply on the bark of trees more than those of the other two species. The bark of the trees seems to be a relatively unproductive microhabitat in the breeding season, so woodpecker species use, to different degrees, the food supply of the foliage as well. The food and the foraging behaviour of the middle spotted woodpecker show that this species feeds on prey living both on barks and in the foliage; it occupies-an intermediate position between the great and the lesser spotted woodpeckers. Prey size did not correlate with predator size suggesting that woodpeckers adapted not to the summer resources but rather the winter ones.

In a stepwise regression analysis, oak habitat area and habitat isolation were the most important parameters explaining numbers, density, regularity, and probability of presence in two successive years of middle spotted woodpeckers. No estimate of habitat quality contributed significantly to the equations. A 50% regularity of occurrence during the study period was found in oak areas of 75 ha. It is suggested that, for a small population, habitat fragmentation that gives rise to partially isolated subpopulations will make the population more vulnerable. The large area required by Swedish middle spotted woodpeckers compared with Central European ones, is believed to be a result either of an ‘extinction disequilibrium’ or of poorer habitats in the periphery of the distribution area of the species.

During winter and spring the oak Quercus robur, was the tree species most utilized by middle spoiled woodpeckers. In March, saptrees, mainly maples Acer platanoides, were preferred for a short period. In winter the birds foraged in the crowns of oaks but in spring they preferred lower stem parts. Dead branches were utilized more in winter than in spring. The birds mostly used a gleaning and probing technique, which may render the species more senstitive to severe weather conditions than other woodpecker species. Arthropods collected from trees were mostly spiders, beetles, thrips or springtails. The nestlings were mainly fed on scale insects and larvae of moths and sawflies. The oak habitat specialization is believed to be caused by competition for food with other gleaning forest birds. Food shortage might possibly occur during periods of bad weather, causing increased mortality.