The conservation value of paddock trees for birds in a variegated landscape in southern New South Wales. 2. Paddock trees as stepping stones

Abstract

The use of paddock trees as stepping stones by birds was assessedin a grazing landscape in southern New South Wales, Australia. A totalof 70 paddock tree sites was surveyed for 20 min each inthe morning, and 36 sites were surveyed again in the afternoon in March2000. During the surveys, the presence, direction of arrival, anddirection of departure to and from sites was recorded for each bird. Astepping stone effect of paddock trees was examined in two ways: (1) byanalysing the arrival and departure direction of birds relative tosurrounding vegetation cover, and (2) by analysing the departuredirection of birds relative to their arrival direction. An arrivaldirection was obtained for 150 independently acting groups of birds, anda departure direction was obtained for 203 independently acting groupsof birds. Both arrival and departure direction were obtained for 87independently acting groups. Foliage-foraging birds tended to followrelatively densely vegetated areas. There was some indication thatgranivores and nectarivores also preferred to move along denselyvegetated areas. This trend was absent for open-country species. Allgroups of birds examined tended to return to their place of origin ormove in the opposite direction of their arrival. This trend was mostpronounced for nectarivores and the foliage-foraging White-plumedHoneyeater (Lichenostomus penicillatus), and lesspronounced for open-country species and parrots. The results arediscussed in relation to the biology and ecology of the various speciesof birds. We conclude that paddock trees have the potential to enhancelandscape connectivity by acting as stepping stones to assist movement.This further highlights their conservation value as demonstrated in thefirst paper of this series.