Nesting of the Thorn-Tailed Rayadito (Aphrastura spinicauda) in a Pine Plantation in Southcentral Chile

We installed nest boxes for Thorn-tailed Rayaditos (Aphrastrura spinicauda) and monitored their use in a Monterrey pine (Pinus radiata) plantation in the Maule Region, southcentral Chile. Thirty-four breeding pairs built nests in boxes, of which 75% began laying eggs. Nest establishment began in early September and construction lasted 12.8 ± 4.9 days (n = 23). Rayaditos used mainly pine needles, together with mosses, epiphytes, herbs, and animal hair in their nests. Clutch size ranged from two to four eggs (mode = 3) that were incubated for 15.8 ± 1.2 days. Brood size negatively affected mass of nestlings, but was positively related to mass of the parents. Adults had higher body mass and built larger nests than those reported previously for the species on Chiloé Island, where broods are larger and the incubation period is shorter. The provision of artificial cavities allowed Thorn-tailed Rayaditos to nest in the pine plantation. Nest boxes combined with other management tools, such as maintaining snags and understory enhancement, may be important factors in mitigation of negative effects of pine plantations on secondary cavity-nesting birds.