Characteristics of Lesser Spotted Woodpeckers Dendrocopos minor on irruptive autumn movement along the coast of southern Norway

The Lesser Spotted Woodpecker Dendrocopos minor is a facultative autumn migrant in Fennoscandia, but there is little published information about its migratory ecology. Analysing data from 26 years (1990–2015) of trapping at Lista Bird Observatory, southern Norway, we found that autumn migration varied in relation to sex and age in this species. Annual numbers of trapped birds fluctuated between 0 and 19 but there was no significant temporal trend in the numbers of birds trapped. However, the numbers were positively correlated with similar data from Falsterbo Bird Observatory in southern Sweden. Thus, the annual fluctuation of Lesser Spotted Woodpeckers at Lista probably reflects the situation across larger parts of the southern Scandinavian Peninsula. In total, 96% of the birds trapped at Lista (n = 136) were in their first calendar year, showing clear evidence for differential migration in the species. There was no sex bias in the material but the median arrival date was about 14 days earlier in males than in females. Wing length increased over the season in both sexes, although the explanatory value of this seasonal progression was low. Also, body mass was higher in males than in females and increased with date of trapping when body size (wing length) was controlled for. Our findings comply with the hypothesis that annual fluctuation in the number of migrating Lesser Spotted Woodpeckers is caused by varying breeding success in the source population(s), mediated by intra-specific competition (the competitive release hypothesis).

Responsiveness to acoustic stimulation, distribution and habitat preferences of the Lesser Spotted Woodpecker, Dendrocopos minor, in Friuli-Venezia Giulia (North-eastern Italy)

From 2005 to 2013 in Friuli-Venezia Giulia (NE Italy), using the playback method, a study on the Lesser Spotted Woodpecker, <em>Dendrocopos</em> <em>minor</em>, was carried out. The aims were to identify the trends in distribution, the range, and the habitat preferences, along with the evaluation of the responsiveness to acoustic stimulation. The Lesser Spotted Woodpecker responded in 10.67% of the points where a conspecifics stimulus was emitted, demonstrating a “strong” responsiveness to the first stimulus. In the case of a response, males prevailed, and the Lesser Spotted Woodpecker was confirmed as the <em>Picidae</em> species that tended to show itself the most (79.17% of the points). Thanks to the tendency to expand the range and to occupy new zones within the known range, most of the suitable environments were occupied in the Provinces of Trieste and Gorizia and from the lowlands to the outer prealpine zone, even in urban areas. In the montane zone, expansion occurred through ascending of the valleys and slopes. The species was found from sea level to 1200 m (mean altitude: 429±270 SD m a.s.l.) and particularly below 800 m a.s.l. (about 90% of the contacts). Of all the contacts, 71.69% occurred in broadleaf woodlands. Woodlands along watercourses were revealed to be very important (most highly represented forest type with more than one fifth of contacts), which have allowed the species to live in the lowlands and subsequently colonize other suitable environments, and the countryside and orchards, which are fundamental in the mountains for the spread and permanence of the taxon. In some areas, densities of 1.11-2.50 territories/100 ha were obtained. In Friuli-Venezia Giulia, a population of 150-190 pairs has been estimated, with an increase of just over 60% compared to the beginning of the century. Finally, some aspects concerning conservation-related problems are reported.

Habitat Preference of Great-Spotted Woodpecker (Dendrocopos major Linnaeus, 1758) and Lesser-Spotted Woodpecker (Dendrocopos minor Linnaeus, 1758) in the Presence of Invasive Plant Species - Preliminary Study

This study was carried out in Hungary, in an old, unmanaged, riparian poplar-willow forest, where two invasive tree species, the green ash and the boxelder maple are presented and reproduce more effectively therefore are more abundant than the native species in the study area. There are also invasive hybrid wild grapes to be found. These invasive plants cause widespread problems in floodplain forests in Central Europe. We studied Great-spotted and Lesser-spotted Woodpeckers. We investigated the following questions: Which tree species are preferred by the foraging birds? How are the foraging birds distributed spatially between the microhabitats? Are there any differences in terms of foraging niche utilization between the two studied species? We gathered our data through weekly standard observations throughout two whole years. Based on our findings we could determine that both species preferred the less abundant native trees rather than the invasive ash and maple trees, though Lesser-spotted Woodpeckers preferred hybrid wild grapes the most. Great-spotted Woodpeckers preferred the middle heights of the trees, they also moved mainly on trunks. Lesser-spotted Woodpeckers used the thinnest branches in the canopy. Based on our results we predict that the decrease of the native tree species may create a suboptimal habitat compared to the current situation. As the studied species are the major cavity excavators, the above mentioned changes will probably have significant effects on numerous cavity dependent species.