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

Abstract

Gábor Ónodi & Tibor Csörgő 2014. 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. -Ornis Hungarica 22 (2): 50-64. AbstractThis 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.Összefoglalás A vizsgálatot a Közép-Tiszai Tájvédelmi Körzetben, egy 60-70 éves, kezeletlen fűz-nyár ártéri erdőben végeztük. A területen két invazív fafaj fordul elő, az amerikai kőris és a zöld juhar. E két fafaj terjedése jelentős környezeti problémát jelent Közép-Európa szerte. Másodlagos lombkorona szintet alkotva leárnyékolják az őshonos fák újulatát, allelopatikumaikkal meggátolják az őshonos fűz és nyár csemeték fejlődését. A területen szintén előforduló, invazív, hibrid szőlőfaj szintén problémát jelent. Két harkályfajt, a nagy és a kis fakopáncsot vizsgáltuk. A következő kérdésekre kerestük a választ: A táplálkozó-pihenő madarak mely fafajokat preferálják? Az egyedek milyen téreloszlásban vannak jelen a fákon? A fafaj preferenciák vizsgálatához felmértük az egyes fásszárú fajok gyakoriságát. Az adatokat egy teljes éven át, heti rendszerességgel gyűjtöttük. Az amerikai kőrist és a zöld juhart egyik vizsgált faj sem preferálta. A nagy fakopáncsok legjobban a fűzfákat, a kis fakopáncsok a hibrid szőlőket részesítették előnyben. A nagy fakopáncsok a fákon főként a felsőbb régiókban, a törzsön, a kis fakopáncsok a lombsátor legvékonyabb ágain mozogtak. A jelenlegi állapothoz képest az őshonos fafajok állo-mánycsökkenése a két h...

Nest site characteristics of the Great-spotted Woodpecker in a bottomland riparian forest in the presence of invasive tree species

“…Among native trees, nest site plots had more trees from all of the available three species, but the difference was proportionately bigger in terms of willow and black poplar hybrid trees, than white poplar hybrids. In one of our earlier studies made in the same study area, through weekly standard, year-round foraging observations, we found, that invasive tree species were avoided (Ónodi & Csörgő 2014). In spite of that, among other tree species, the rough barked native willow and black poplar hybrids were the most preferred trees for foraging (Ónodi & Csörgő 2014).…”

“…In one of our earlier studies made in the same study area, through weekly standard, year-round foraging observations, we found, that invasive tree species were avoided (Ónodi & Csörgő 2014). In spite of that, among other tree species, the rough barked native willow and black poplar hybrids were the most preferred trees for foraging (Ónodi & Csörgő 2014). The green ash and boxelder maple were scarcely used for foraging by the study species (Ónodi & Csörgő 2014).…”

“…In spite of that, among other tree species, the rough barked native willow and black poplar hybrids were the most preferred trees for foraging (Ónodi & Csörgő 2014). The green ash and boxelder maple were scarcely used for foraging by the study species (Ónodi & Csörgő 2014). This could be due to that these tree species have very few prey items in them.…”

“…Although living trees were preferred by the foraging birds, nest site plots had proportionately less living trees than random plots. This could be from the fact that most of the living trees in the study area are invasive and thus avoided by the foraging birds for both foraging and nesting (Ónodi & Csörgő 2014).…”

“…As a generalist species could have a crucial role in such altered communities as the main cavity-excavating species. For further understanding, it is important to study the habitat use of this species in such transformed habitats (Ónodi & Csörgő 2013(Ónodi & Csörgő , 2014.…”