Atlas of Habitats

group

0.0006 m³

at 3.2 m

48.2ºN

[ovoidal] pocket

wood

mixed

rough

mixed

[ovoidal] pocket

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habitat

Introduction

Austria
Floridsdorfer Wasserpark, Vienna
48.2501° N 16.4047° E
31/03/2024, 12:00 pm

This habitat archive highlights an ovoidal cavity found in a tree trunk located at the Floridsdorfer Wasserpark, Vienna, and initially excavated by a bird, most likely a woodpecker. The cavity has since become home to a colony of wasps, illustrating a significant interspecies dependency. Such natural habitats underscore the intricate ecological relationships that exist within urban ecosystems like this park.

Micro Climate

After the bird abandoned the cavity, it was colonized by a wasp colony. The cavity's structure provides ideal protection from weather extremes and predators, essential for the wasps’ nest. This instance of secondary occupancy underscores a form of interspecies facilitation – in which the labor of one species (bird) benefits another (wasps), enhancing the habitat’s biodiversity and illustrating ecological resilience.

Material

The tree, likely from the Salix (willow) or Populus (poplar) species, which are both prevalent in riparian areas of the park, provides an ideal substrate for cavity formation. Over time, the wood becomes decayed and softened, either through natural senescence or external factors like fungi, making it more accessible for excavation by birds. The physical condition of the tree – moisture content, stage of decay, and structural stability – plays a pivotal role in determining where birds create their cavities.

Location

Floridsdorfer Wasserpark is a critical component of Vienna's urban green infrastructure, featuring a mosaic of wetlands, meadows and woodlands that contribute to the city’s biodiversity. Its location near the Danube enhances its ecological significance, as it serves as a refuge for various species, especially cavity-nesting birds and insects. The park's vegetative richness supports dynamic interspecies interactions like the one documented here, where urban ecology fosters diverse life forms that thrive in natural yet human-adjacent environments.

Construction

The bird, most likely a woodpecker, used its strong, chisel-like beak to excavate the cavity by systematically removing wood fibers to create an ovoidal hollow. The shape and size of the cavity are tailored to the bird’s nesting needs, providing insulation and protection for its young. The direction and depth of the cavity are carefully calculated, factoring in tree health, location on the trunk, and external environmental threats, ensuring a stable, protective nesting site.