Breeding Biology of the Thorn-Tailed Rayadito (Furnariidae) in South-Temperate Rainforests of Chile

Abstract

We conducted a study of the breeding biology of the Thorn-tailed Rayadito (Aphrastura spinicauda) in secondary forests on the continental island of Chiloé (42° S), southern Chile. Rayaditos are small insectivorous furnariids inhabiting the south-temperate forests of Chile and Argentina. We followed the reproduction of rayadito pairs breeding in nest-boxes. Rayaditos build their nests mainly of rhizomes and stems of epiphytic vines, grasses, and hairs during periods of at least a week, and show a marked population asynchrony in laying dates of more than two months (October–December). Rayaditos lay clutches of 3–6 eggs with a mode of 4 and laying occurs on alternate days. Eggs are 50% larger and hatchlings are 30% larger than expected from allometric equations. Most broods hatch synchronously. Nestling growth curves adjust well to logistic functions and at 2 weeks nestlings attain masses similar to asymptotic values. Nestling growth, which occurs over 3 weeks, is 27% slower than expected from allometry. Fledglings attain adult size with respect to tarsus length, but have less developed plumage and higher body mass than adults. Rayaditos exhibit clutch and brood reduction, suggesting possible food limitation. The protracted breeding periods may preclude second breeding attempts for most pairs in Chiloé. There is evidence for declines in parental quality with season. The low seasonal fecundity, large eggs, and prolonged dependence periods of a truly south-temperate species like the Thorn-tailed Rayadito reflect a ‘slow’ life history similar to that of tropical passerines. Biología Reproductiva de Aphrastura spinicauda (Furnariidae) en Bosques Lluviosos Templados Meridionales de Chile Resumen. Realizamos un estudio de la biología reproductiva del Rayadito Aphrastura spinicauda en bosques secundarios de la isla continental de Chiloé (42° S), sur de Chile. Este pequeño furnárido insectívoro habita los bosques templados meridionales de Chile y Argentina. Seguimos las actividades reproductivas de parejas de rayaditos que utilizaron cajas artificiales para nidificar. Los rayaditos construyen sus nidos utilizando rizomas, hierbas y pelo durante períodos de al menos una semana, y muestran una marcada asincronía a nivel de población de más de dos meses (octubre a diciembre) en el inicio de la puesta. Las puestas incluyen de 3 a 6 huevos, con un tamaño modal de 4 huevos, los cuales son puestos en días alternos. Los huevos son 50% más grandes y los polluelos recién eclosionados 30% más grandes de lo esperado según ecuaciones alométricas. La mayoría de las nidadas eclosionan sincrónicamente. Las curvas de crecimiento se ajustan bien a funciones logísticas y el peso alcanza valores asintóticos a las dos semanas. El crecimiento de los polluelos, que ocurre durante un período de permanencia en el nido de tres semanas, es un 27% más lento de lo esperado por alometría. Los volantones alcanzan el tamaño adulto con respecto a la longitud de tarso, pero presentan un plumaje menos desarrollado y un mayor peso que los adultos. Esta especie presenta casos de reducción de la puesta o de la nidada, lo que sugiere posibles limitaciones en la disponibilidad de alimentos. Los prolongados períodos de reproducción pueden impedir el inicio de segundas puestas en Chiloé. Hay evidencia de disminuciones estacionales en la calidad parental. La baja fecundidad anual, el gran tamaño de los huevos y el prolongado periodo de crecimiento del Rayadito refleja una historia de vida ‘lenta’ similar a la de paseriformes tropicales.

Genetic differentiation of the Thorn‐tailed Rayadito Aphrastura spinicauda (Furnariidae: Passeriformes) revealed by ISSR profiles suggests multiple palaeorefugia and high recurrent gene flow

“…Among the birds most frequently seen in woodlands, the Thorn-tailed Rayadito is a small insectivorous furnariid that occasionally ingests fruit and seeds (Goodall et al 1951, Jaksic & Feinsinger 1991, Ridgely & Tudor 1994, Estades 1997, Remsen 2003, constructs domed vegetative nests within cavities, exhibits sexual dimorphism and has a unique breeding biology among cavity nesters (Zyskowski & Prum 1999, Moreno et al 2005, 2007. Based on variation in coloration and morphological differences, three subspecies are recognized: Aphrastura spinicauda spinicauda, which inhabits isolated relict forests of Olivillo Aextoxicon punctatum on the mainland extending from northern Chile (30°S) to Tierra del Fuego, Staten Island, Diego Ramírez Island, and is accidental on the Falkland Islands in the southern Atlantic; Aphrastura spinicauda fulva, occurring on Chiloé Island; and Aphrastura spinicauda bullocki, endemic to Mocha Island ( Fig.…”

Age and terminal reproductive attempt influence laying date in the thorn‐tailed rayadito

“…The species is socially monogamous; both members of the pair contribute to nest building, incubation and the feeding of nestlings (Moreno et al 2007, Espíndola-Hernández et al 2017). Females lay one clutch per breeding season, during the austral spring, from October to December (Moreno et al 2005). Nest construction takes 9-20 d, the incubation period is 15-22 d and fledging occurs 20-21 d after hatching (Altamirano et al 2015).…”

“…Nest construction takes 9-20 d, the incubation period is 15-22 d and fledging occurs 20-21 d after hatching (Altamirano et al 2015). Eggs are laid on alternate days and incubation is delayed until the clutch is completed (Moreno et al 2005). Clutch size varies according to latitude, with a mean clutch size of 2.5 eggs at lower latitudes and 4.5 eggs at higher latitudes (Quirici et al 2014).…”

Variation in fine‐scale genetic structure and local dispersal patterns between peripheral populations of a South American passerine bird

“…Data for our study were obtained during eight consecutive breeding seasons (2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015) in both localities. Adults were captured inside the nest boxes when feeding 12-to 14-day-old nestlings using a manually triggered trap (see details in Moreno et al, 2005;Quirici et al, 2014). Adults and nestlings were marked with a uniquely numbered metal ring, and blood sampled (ca.…”