Collared Forest Falcon (Micrastur semitorquatus) Science Article 2
The Barred Forest-Falcon (Micrastur ruficollis) and Collared Forest-Falcon (M. semitorquatus) are cavity nesters with similar geographic distributions but differences in body size. For Barred and Collared forest-falcons, nest height averaged 17 and 20 m above ground, nest tree dbh averaged 95 and 167 cm, and nest depth averaged 81 and 47 cm, respectively. Most forest-falcon nesting attempts were in Cedrela mexicana: 33% for Barred and 44% for Collared forest-falcons. Nesting attempts in live trees were more successful than those in dead trees or snags. Inter-nest distances averaged 1.04 and 3.28 km for Barred and Collared forest-falcons, respectively. The breeding density calculated from inter-nest distance yielded estimates of 1 territorial pair/0.98-1.08 km2 for Barred Forest-Falcons and 1 territorial pair/9.6-10.5 km2 for Collared Forest-Falcons.
Russell Thorstrom, ORNITOLOGIA NEOTROPICAL 12: 337-343, 2001