Key Elements of the White-Backed Woodpecker’s (Dendrocopos leucotos lilfordi) Habitat in Its European South-Western Limits

Abstract

In the last decade, the population of the white-backed woodpecker (Dendrocopos leucotos lilfordi) (WBW) in Navarre has been reduced mainly due to the loss of suitable habitat for this species from intensive forest management, leading almost to its extinction. This study aimed to identify the key structural elements of breeding habitats of the WBW and analyze their effect on the composition of the saproxylic fungi community within the habitats. In the Special Area of Conservation, namely Quinto Real in Navarre, 20 circular plots (500 m2) and 10 transects (150–300 m) were located inside and outside WBW territories. Within each sample plot, forest structure, deadwood, microhabitats, regeneration, and saproxylic fungi community were studied. The results showed that the key elements in the WBW territories were high trees, high diversity of deadwood (with a high presence of big and late-decay deadwood), high snag volume, and high microhabitat diversity. Although the past management is also evident in the variability of some of those characteristics, this species is well adapted to different structural and compositional conditions of the territory. The saproxylic fungi community was richer among the WBW territories, and in those areas, the presence of Fomes fomentarius was high, compared to non-WBW territories where it was not present. In conclusion, to maintain and protect the studied population, it is necessary to implement sustainable management that guarantees the conservation of the key elements for the WBW territories (structural heterogeneity and high deadwood diversity) in order to increase the suitability of the habitat for WBWs.

Characteristics of nest cavities used by White-backed Woodpecker (Dendrocopos leucotos) in Hungary

“…Ultimately, White-backed Woodpeckers are strongly associated with mature deciduous trees and deciduous deadwood. Numerous studies from across the range have shown that reasonably large areas of unmanaged old-growth forest with a high proportion of deadwood, standing and fallen, are required for both foraging and breeding (Håland & Ugelvik 1990, Costantini & Melletti 1992, Grangé 1993, 2016, Virkkala et al 1993, Hogstad & Stenberg 1994, Bernoni 1995, Mikusiński & Angelstam 1998a, 1998b, Frank 2002, Håpnes 2003, Melletti & Penteriani 2003, Pavelka 2003, Garmendia et al 2006, Czeszczewik 2009, Gerdzhikov et al 2018, Schwaiger & Lauterbach 2019, Urkijo-Letona et al 2020, Bühler 2021. In Hungary, the species generally only occurs in hill forests where there are native deciduous tree species older than 60-70 years and a minimum volume of 20 m 3 /ha of deadwood (Szmorad et al 2018).…”