Effects of crop identity and biomass of grain spilled in stubbles on pest-bird abundance in the pampas of central argentina

ZUFIAURRE E.; CODESIDO M.; ABBA A.M.; BILENCA D.

Sevilla

Congreso; 10th European Vertebrate Pest Management Conference; 2015

Agencia Estatal Consejo Superior de Investigaciones Científicas de España

The Argentine Pampas is one of the richest agricultural regions of the world. Eared Dove (Zenaida auriculata), Monk Parakeet (Myiopsitta monachus), and pigeons (Patagioenas picazuro and P. maculosa) have become major pest-bird species of standing crops in agricultural landscapes of Argentina. However, little is known about abundance of these species after harvest, considering that spilled grain in stubbles may contribute to sustain granivorous bird populations. The aim of this study was to assess the effects of crop identity and the amount of grain spilled in stubbles on pest-bird abundance. During 2011-2013, we randomly sampled 167 plots (spring-summer: stubbles of wheat -N=45- and barley -N=33-; autumn: soybean -N=50-, corn -N=26- and sunflower -N=13-). In each plot we established a 600x100m transect in order to record pest-birds. We sampled grains spilled at each plot and calculated biomass. Mean biomass of grains spilled by plot ranged between 150±16 kg/ha for wheat and 293±105 kg/ha for corn, whereas all pest-birds were more abundant in autumn (3.8±1.1, 1.4±0.4 and 0.4±0.1 ind/ha) than in spring-summer (1.2±0.3, 0.5±0.2 and 0.3±0.1 ind/ha for doves, parakeets and pigeons, respectively). Generalized linear mixed models revealed that abundance of all species were associated with the identity of crop rather than biomass. During spring-summer, doves and pigeons were more abundant in wheat stubbles, whereas during autumn, doves were more abundant in sunflower and parakeets in corn stubbles. These results show a relative greater influence of crop identity rather than biomass of spilled grains available in stubbles on the abundance of pest-birds.