Temporal and spatial variations of the avian communities of the forest of Caldén, Parque Luro, La Pampa, Argentina.

CID, F.D.; MACEDA, J. J.; ENRIQUE CAVIEDES VIDAL

Merlo, San Luis

Congreso; Reunión Anual de la Sociedad de Biología; 2004

TEMPORAL AND SPATIAL VARIATIONS OF THE AVIAN COMMUNITIES OF THE FOREST OF CALDEN, PARQUE LURO, LA PAMPA, ARGENTINA Cid FD, Maceda JS, Caviedes- Vidal E Unidad Invest Cs Biol, Univ Nac Sun Luis, 5700 Sun Luis; *Univ Nac La Pampa. Email: fcid@unsl.edu.ar An avian community is largely affected by the structure of the habitat and seasonal changes. We studied the species composition and seasonality of the avian communities in two environments with different plant composition and structure: open (BA) and closed (BD) forest of Prosopis caldenia (Parque Luro). Data were collected from 12 transects (25Ox30m) during autumn, winter and spring of 1998. We recorded 53 bird species, 41% of species cited for the phytogeographic region "El Caldenal". Avian richness (S) and abundance (N) was higher in BD (N=1773; S=47) than in BA (N=l170; S=38). Avian diversity (Shannon index; t-Hutchenson, pe0.05) was also higher in BD than in BA during autumn and winter, but not in spring. seasonal habitat diversity of BA was low in winter and, during spring, for BD. Bird species were assigned to five trophic guilds. Omnivores were only present during spring and winter. Richness of BD in terrestrial granivores (GT), flying insectivores (FI) and terrestrial insectivores was increased during spring. The abundance of arboreal herbivores was higher in BD than BA. In summary, temporal and spatial variations were registered in avian communities present in the open and closed forest of Caldén. In addition, the community composition is not stable during the year: Different species assemblages are present in each season, the annual resident and the seasonal species.