Every year at this time (Oct/Nov) our open woodlands where I live see huge flocks of White-browed woodswallows accompanied by 3 other species of woodswallows. The White-browed would be the most attractive and nest almost anywhere even on top of a rain-gauge. Their preference though, if available, is behind peeling tree-bark as seen here.
EOS 5D, EF 70-200 F2.8L plus x1.4 converter @ 280mm. Manual exposure - ISO 640, 1/200 sec F11, fill flash minus 1.75, Tripod, Hide on tower set-up.