Bird Community Studies

Field studies are being carried out to determine how the different native forest habitats are used by bird communities throughout the year. Specifically, this focuses on three research issues:

1. Does forest bird assemblage richness, composition, relative abundance and diversity vary through the year ?

2. Does forest bird assemblage richness, composition, relative abundance and diversity vary in an altitudinal and vegetational gradient?

3. Does forest structure explain differences in bird assemblage diversity between pristine old growth and disturbed forests?

METHODS

Bird community sampling

The study is being carried out in two areas: Huerquehue national park as the old growth forest and the private reserve “El Cañi” as the secondary forest site.

In the two areas, 15 census sites have been established in the three habitat types distributed along an altitudinal gradient (Fig. 1). Five Point counts will be established in each habitat type. The point counts sites will be separated by at least 150m horizontally between each other and 200m vertically.

Grafico

Fig. 1 Altitudinal three habitat types were 15 point counts and 6 mist will be carried out in the two areas.

In each area, 6 (2 for each habitat type) of the point counts sites will be complemented using mist nets for 6 hours per day starting at sunrise (Whitman 2004).

Characterization of habitat structure

At each site, we will use compositional and structural elements or properties of forests that could be important for bird habitat. These are: availability of large trees (larger than 60cm DBH), dense understory, fallen logs and tree density. We will quantify this abundance of this elements to empirically assess their importance for birds.

Data being collected

Species richness
Species composition
Species relative abundance
Diversity
Morphometric measures of birds captured with mist nests and band code for each bird
Site where it was observed (air, ground, or tree)
Habitat quantitative features (compositional and structural)

Bird Survey

Lightweight nets are used to trap small woodland birds, so they can be identified, measured, ringed and released unharmed.