Do increases in the availability of standing dead trees affect the abundance, nest-site use, and niche partitioning of great spotted and middle spotted woodpeckers in riverine forests?

Abstract

Standing dead trees may be a limited resource for woodpeckers in managed forests, especially for species that rely on dead wood for their nest or roost cavity, and as foraging sites. Effective conservation strategies for woodpeckers require a detailed knowledge of species' responses to dead wood availability. To investigate the importance of standing dead wood (snags) for the abundance and nest-site use of the great spotted woodpecker Dendrocopos major and middle spotted woodpecker Leiopicus medius in mature riverine forests, we compared the responses of birds between two periods-before mass mortality, and during a pulse in standing dead trees. The density of standing dead trees available for cavity excavation by the great spotted woodpecker and the middle spotted woodpecker increased significantly during the study period: 37-fold and 4-fold, respectively. Temporal trends in the abundance of both woodpecker species from 2000 to 2015 were not significant. Great spotted woodpeckers were significantly more likely to use dead trees and places with wounds in species other than oak and ash during the outbreak period than in the pre-outbreak period. Middle spotted woodpeckers were significantly less likely to excavate cavities in tree species other than oak and ash in the outbreak period, but dead trees were more likely selected. An interspecific comparison suggests that the probability of a nest-hole having been excavated by a middle spotted woodpecker increased with a nest-hole sited in ash, in a dead tree, in a limb/branch, and decreased with 123Biodivers Conserv (2018) 27:123-145 https://doi.org/10.1007/s10531-017-1425-6 a nest-hole in a closed forest. These findings suggest that woodpecker species, especially weak excavators, may benefit from an increase in dead wood availability leading to nest niche shifts into more favorable substrates for cavity excavation. However, a strong increase in dead wood availability does not modify the general pattern of niche partitioning between great spotted and middle spotted woodpeckers. Conservation plans for the specialized middle spotted woodpecker must consider the preference for dead and decaying trees. The decreasing number of large ashes and oaks, and the lack of natural regeneration of the latter species, may negatively affect the middle spotted woodpecker in the future.

Population dynamics and regulation of the Middle Spotted Woodpecker in strictly protected and managed forests in Western Poland

“…The increase in population size of the Middle Spotted Woodpecker is also attributed to the availability of dead trees, which may improve their food base and play an important role in nest-site selection (Pasinelli 2000;Weggler et al 2013;Schuck et al 2018). However, as previously stated, we did not find any evidence that the Middle Spotted Woodpecker tended to increase in abundance after a pulse in deadwood availability in CFR (Kosiński et al 2018). Moreover, we did not observe a negative effect of deadwood removal on population abundance in LF.…”

“…As stated earlier, sanitary felling and salvage logging did not affect population growth rate in LF. Furthermore, we did not observe a temporal trend in the Middle Spotted Woodpecker abundance in CFR during 2000-2015, i.e., before and after the mass mortality of oaks and ashes (Kosiński et al 2018). On the one hand, these results suggest that forest thinning and natural disturbances probably do not distinctly improve the accessibility of food for Middle Spotted Woodpeckers, mainly smaller bark surface-dwelling arthropods (Pasinelli 2003), or their effects are delayed.…”

“…CFR is a part of both the Natura 2000 Special Protection Area Middle Warta River Valley PLB300002, with the Middle Spotted Woodpecker as one of the target species (Wilk et al 2010), and the Ostoja Nadwarciańska Special Area of Conservation PLH300009. Further characteristics of the forest stands and their management can be found elsewhere (Kosiński et al 2018).…”

Contribution of European forests to safeguard wild honeybee populations

“…Our results showed that conifer‐dominated forests are generally poorer in microhabitats, especially in tree cavities (see also Paillet et al., ). This is likely related to the foraging and nesting habits of cavity excavators, which tend to prefer broadleaved trees (e.g., Kosinski et al., ; Rolstad, Rolstad, & Saeteren, ), as well as to the higher persistence of decayed cavities on broadleaved trees (Paillet et al., ; Wesołowski, ). Unsurprisingly, unmanaged forests displayed significantly higher cavity densities than their managed counterparts, due to the higher occurrence of large trees and snags in these forests (Kozák et al., ; Paillet et al., ).…”

Significant Asia‐Europe divergence in the middle spotted woodpecker (Aves, Picidae)

“…(Ciudad, Robles, & Matthysen, 2009;Jenni, 1983;Kosiński, 2006;Pasinelli & Hegelbach, 1997;Pettersson, 1983;Robles et al, 2007). Trees suitable for cavity excavation are important resources for this woodpecker, since it typically excavates a new cavity each year and rarely reuses old cavities (Hebda, Wesolowski, & Rowinski, 2016;Kosiński & Winiecki, 2004;Kosiński et al, 2018;Pasinelli, 2000Pasinelli, , 2007. Its breeding success is affected by weather conditions during the nestling period most likely through food abundance (Kossenko & Kaygorodova, 2007;Pasinelli, 2001).…”