Noronha Elaenia is endemic to the Fernando de Noronha archipelago (03°50′25″S, 32°24′41″W), 350 km off north-east Brazil. The archipelago comprises 26 islands, of which Noronha Elaenia occurs on three: Meio, Rata and the main island. The species is listed as Vulnerable (BirdLife International 2016) and is the only Elaenia species confined to an island. It inhabits scrub, woodland and gardens, and is presumed to breed in February–May (Nacinovic & Teixeira 1989, Antas et al. 1990, Licarião 2017). The taxonomic relationships of E. ridleyana are unclear, as the species has not been sampled molecularly (e.g., by Rheindt et al. 2008), but Straube & Rodrigues (2016) pointed to the many similarities between it and Large Elaenia E. spectabilis. The latter occurs over much of Brazil, except the extreme north, as well as widely east of the Andes south to northern Argentina but probably only as non-breeding visitor north to south-east Colombia and over much of Amazonian and north-east Brazil (Hosner & Kirwan 2020).

Here, we report the first record of Noronha Elaenia on Atol das Rocas (03°51′30″S, 33°49′29″W), 145 km west of Fernando de Noronha, the only atoll in the South Atlantic and one of the smallest in the world (Fig. 1). Thirty species of birds have been recorded on the atoll, including residents, migrants and vagrants, and thousands of seabirds nest there, but there are no breeding landbirds due to the lack of permanent fresh water (Schulz-Neto 2004).

On 16 June 2021, we recorded a Noronha Elaenia perched on a coconut tree (Fig 2a). It stayed in the area for four days and was heard singing. A House Sparrow Passer domesticus was observed at the same site, and this species has been by us in other years (annually since 1999) in flocks of up to nine individuals, always in the rainy season during the first half of the year, when freshwater resources are available in reservoirs. As shown in Fig. 2a, the Noronha Elaenia had rounded tips to the rectrices, a characteristic of adults (ICMBIO 2020) suggesting that birds of this age may sometimes attempt to disperse away from Noronha.

Although the first record of Noronha Elaenia on Atol das Rocas, our observation does not appear to be the first away from Fernando de Noronha. Twice, during research by Operations Sueste on the Almirante Saldanha, elaenias have been reported at sea, but unfortunately details of their locations are no longer available. First, an individual was captured in one of the ship's cabins in July 1982; at the time, it was identified as Olivaceous Elaenia E. mesoleuca because of the lack of white on the pileum. Second, in February 1983, an elaenia was photographed on the railing of the ship (Straube & Rodrigues 2016) and which we believe it is parsimonious to assume was a Noronha Elaenia. In the absence of any molecular-phylogenetic data, these observations necessarily resurrect discussions concerning the species' taxonomic validity. Straube & Rodrigues (2016), in their detailed review of the taxonomic history of Noronha Elaenia, while not excluding the possibility that it is a valid endemic species, noted the paucity of diagnostic characters from and the migratory nature of, especially, E. spectabilis, Small-billed Elaenia E. parvirostris and Yellow-bellied Elaenia E. flavogaster (Rheindt et al. 2008), which may provide a clue as to the origin of the modern-day Elaenia population on Fernando de Noronha and its relationships.

Figure 1.

Location of Atol das Rocas atoll in relation to the Fernando de Noronha archipelago and mainland Brazil.

Figure 2.

(A) Noronha Elaenia Elaenia ridleyana, Atol das Rocas, 16 June 2021 (Maurizélia de Brito Silva); (B) Fernando de Noronha, 20 June 2021; an individual banded by the project Aves de Noronha (© Heideger Nascimento)

Migratory elaenias are capable of crossing long distances (Chesser 1994). For example, White-crested Elaenia E. albiceps chilensis can fly 500–600 km/day, including across deserts and grasslands (Bravo et al. 2017). Given that the distance between Fernando de Noronha Atol das Rocas is just 150 km, and the prevailing winds between them are from the east (Kikuchi & Schobbenhaus 2002), it seems safe to assume that our record involved Noronha Elaenia. Whether E. ridleyana is capable of reaching mainland Brazil is unknown but this record raises questions as to whether there is gene flow between Noronha Elaenia and other Elaenia.