Lathrotriccus euleri (Cabanis, 1868)

Melo, Tomaz Nascimento de & Greeney, Harold F., 2019, Notes on the breeding biology of birds in riverine floodplains of western Amazonia, Bulletin of the British Ornithologists’ Club 139 (1), pp. 56-64 : 61-62

EULER’S FLYCATCHER Lathrotriccus euleri

On 6 September 2017 a nest was discovered in the same lowland forest where those of Phaethornis hispidus and Cranioleuca gutturata were found, sited in a dried cocoa Theobroma cacao fruit ( Malvaceae ), 1.24 m above ground ( Fig. 6 ). The entrance was a hole in the side of the fruit, and the interior was covered by dark rootlets, small fibres and green moss, forming a shallow cup. It was not possible to take measurements, but the nest held two pinkish eggs with reddish-brown spots at the large end. Only one adult was observed at the nest. This species constucts a cup-shaped nest of fibres, and uses small holes ( Farnsworth & Lebbin 2004). Londoño (2014) depicted a similar nest, in the Peruvian Amazon, with two apparently identical eggs, but constructed in a natural cavity. Possibly this is the first formal description of a nest of L. euleri in Amazonia, but its breeding biology in the south and south-east of its range is well known ( Di Giacomo & López Lanús 1998, Aguilar et al. 1999, Marini et al. 2007, Auer & Bassar 2009). There, nests are shallow cups constructed in natural cavities in trees, fallen logs or in ravines, with a mean height above ground of 2 m. The clutch is two or three eggs.

Although Stouffer et al. (2013) did not identify a well-defined breeding season for central Amazonian upland birds, landscapes in the floodplains are subject to strong transformation between the dry and wet seasons due to the dynamics of the flood ( Wittmann et al. 2010), which can alter the availability of nest sites ( Beja et al. 2010). Of the species for which breeding activity was registered in the Madeira floodplain, five bred when water levels were falling (June/July) and one in the dry season (September). Although the same sites were sampled as in the early wet season (December), when the Madeira River is at its highest level (March) TNM did not find any evidence of nesting activity. However, Leite et al. (2016) found an active nest of Leaden Antwren Myrmotherula assimilis at the Juruá River during its peak flood (March). Environments in the floodplains change completely between the dry and wet season, creating different opportunities for nesting, presumably depending on the natural history attributes of a given species.

Figures

Figure 6. Nest and eggs of Euler’s Flycatcher Lathrotriccus euleri in a dried cocoa Theobroma cacao fruit (Malvaceae), Rondônia, Brazil, September 2017 (Tomaz Nascimento de Melo)