Breeding biology of the Wren-like Rushbird (Phleocryptes melanops) at the southeast Pampas of Argentina

CHIARADIA NICOLAS MARIANO; CARDONI D AUGUSTO; PRETELLI MATIAS G; ISACCH JUAN PABLO

WILSON JOURNAL OF ORNITHOLOGY

WILSON ORNITHOLOGICAL SOC

Año: 2017 vol. 129 p. 46 - 52

1559-4491

Between 2013-2015 we conducted a study on the breeding biology of the Wren-like Rushbird (Phleocryptes melanops) in wetlands of the Pampas region, Argentina. The search of Rushbird nests was conducted, by several researchers walking into the wetlands, in three ways, by observing adults carrying material, through singing adults next to the nest or from the active search for nests in the vegetation. Nests were visited at intervals of 3?5 days. Of the 245 nests encountered (153 nests in 2013?2014 and 92 nests in 2014?2015) in 97 were found eggs. The egg-laying period lasted almost three months (late September- late December). The mean clutch size was 2.7 ± 0.5 eggs (mean ± SD) (range = 1-3; n = 63), and the total time of nesting period was 34 ± 2.5 days (mean ± SD), with an incubation and chick-rearing periods of 18 ± 1.63 days and 16 ± 0.50 days, respectively. From the total number of nests found, 43% of them were abandoned during building, 38% of nests were predated, 14% of nests (n = 33) were successful, while 5% of nests were destroyed. Nest predation was higher during the incubation (80%) than during chick-rearing period (20%). The nesting success was on average of 23% (25% for the 2013?14 and 21% for the 2014?2015) for the entire nesting. We also observed a relatively higher plasticity than previously reported in relationship to vegetation used to fix nests (80% rushes, 20% other plants). Finally, we have observed an abrupt termination of the reproductive period associated with the desiccation the wetlands, 90% of active nests failure (75% was predated and 25% was abandoned) when the wetland was dried