The Wilson Journal of Ornithology 124(4):737-742, 2012 
NESTING OF THE THORN-TAILED RAYADITO (APHRASTURA 
SPIN/CAUDA) IN A PINE PLANTATION IN SOUTHCENTRAL CHILE 
CLAUDIO S. QUILODRAn. 1 RODRIGO A. VASQUEZ, 13 AND CRISTlAN F. ESTADES’ 
ABSTRACI—We installed nest boxes lor I horn-tailed Rayaditos (Aphrastrum spinicauda) and monitored their use in 
a Monterrey pine (Pin us radiata) plantation in the Manic Region, southcentral Chile. Thirty-four breeding pairs built nests 
in boxes, of which 75*7 began laying eggs. Nest establishment began in early September and construction lasted 12.8 ± 
A9 days in = 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 Chilod Island, where broods are larger and the incubation period is 
shoner. The provision of artificial cavities allowed Thorn-tailed Rayaditos to nest in the pine plantation. Nest boxes 
combined w ith oilier management tools, such as maintaining snags and understory enhancement, may be important factors 
in mitigation of negative effects of pine plantations on secondary cavilv-ncsling birds. Received IS February 2012. 
Accepted 7 June 2012. 
The Furnariidae consists of a large variety of 
species that have colonized a wide diversity of 
habitats from tropical rainforests to savannas and 
deserts (Fjeldsa et al. 2005). They are mostly 
insectivorous, socially monogamous, and territo¬ 
rial. Their plumage is typically brown or grayish- 
brown, and males and females are morpho¬ 
logically similar (Zyskowski and Prum 1999, 
Mezquida 2001, Remsen 2003. Rubio and de 
Pinlio 2008). 
The Thorn-tailed Rayadito (A ph rostrum spini- 
cauda) is an endemic member of Furnariidae from 
South American temperate rainforests (Grigera 
1982). It does not exhibit sexual dimorphism and 
has high parental care of eggs and chicks (Moreno 
et al. 2007, van Dongen et al. 2009). Ii is 
territorial during the breeding season (Ippi et al. 
2011), but joins mixed-species flocks during the 
non-breeding season where it is the dominant 
'pecies fVuilleumier 1967, Ippi and Trejo 2003). 
Plantations of exolic Monterrey pine (Pinus 
radiata) have replaced (he original native vege¬ 
tation in southcentral Chile, affecting wildlife 
diversity by homogenizing the landscape (Munoz- 
Pedrcros et al. 1996, Vergara and Simonetii 
2003). The Thom-tailcd Rayadito is considered 
sensitive to habitat fragmentation and patch 
vegetation characteristics (Vergara and Simonetti 
Institutodc Ecoiogia y Biodivcrsidad. Departamento de 
C'ienciaji EcolOgicas. Facultad dc Ciencias, Univcrsidad de 
Chile, Casillu 653. Santiago. Chile. 
‘ fahoratorio de Ecoiogia de Vida Silvestre. Facultad de 
t iencias Forestales y de la Conscrvacibn de la Naturaleza. 
Univcrsidad dc Chile. Casilla l >20b. Santiago. Chile. 
Corresponding author: e-mail: rvasquez@uchile.cl 
2004, Vergara and Marquet 2007), but also 
frequently visits the pine matrix to forage (Estades 
1999, Estades and Temple 1999). Rayaditos use 
small and isolated remnants of native forest 
during the breeding season, where there are 
available tree cavities, a limiting resource for 
nesting (Tomasevic and Estades 2004, 2006; 
Cornelius et al. 2008). 
Pine plantations represent usable foraging 
habitat for Thorn-tailed Rayaditos and may also 
enhance connectivity between remnant native 
vegetation patches (Estades and Temple 1999; 
Estades 2001 h. c: 2006). However, the scarcity of 
cavities in industrial forests severely restricts 
breeding use by the species (Estades 2001b). 
Thus, use of nest boxes has the potential to 
become a habilnt improvement tool to allow 
Thorn-tailed Rayadilos to nest in pine plantations. 
Information about Rayadito breeding biology in 
pine plantations is scant, despite its usefulness to 
assess conservation status as well as species 
responses to environmental disturbances in natural 
and managed habitats (Vasquez and Simonetti 
1999). Our objectives were to; (I) examine if 
Rayaditos can breed in exotic pine plantations if 
they have access to nesting cavities, and (2) 
describe their breeding biology in pine plantations 
for comparison with previously published data 
from a native forest on Chiloe Island, Chile 
(Moreno et al. 2005). 
METHODS 
Study Area .—The study was conducted during 
austral spring 2009 in the Coastal Range of the 
Maule Region. Constitucion Province, southcen¬ 
tral Chile (35 29' S. 72° 21' W) (Fig. I). The 
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