The Gray-hooded Gull (Chroicocephalus cirrocephalus) is a seabird distributed in almost all South American countries. However, breeding information on the species in Brazil is scarce. In this study, literature review and search in online databases (WikiAves and eBird) were carried out to gather breeding information on the species in the country and nests of the Gray-hooded Gull were recorded on the northern coast of the Rio de Janeiro state. Literature review indicated breeding records in Rio Grande do Sul, Rio de Janeiro and Rio Grande do Norte states. On WikiAves, 19 records of the species with nests, eggs, chicks and breeding colonies were reported between 2009 and 2020, in Macau, Rio Grande do Norte and one adult hatching at Rio Grande do Sul. In August 2019, two nests were recorded at Ubatuba lagoon (22°09′S and 41°18′W) in the Restinga de Jurubatiba National Park, in the Quissamã municipality in Rio de Janeiro. The nests were described and monitored during five weeks. Each nest contained two eggs and was built with the grass Paspalum vaginatum. Over time, the eggs were degraded and disappeared from the nests, without signs of hatching and possible predation. This study compiles for the first time all the breeding information on the species in Brazil and contributes with data about the nests and egg biometry.

In Brazil, the White-backed Stilt Himantopus melanurus is distributed in the midwest, south and southeast but breeding information is scarce. In this study, species breeding information in the country was compiled from online platform (WikiAves, eBird) and literature. A case study describing nests and egg biometry were reported in Restinga of Jurubatiba National Park (RJNP), on the north cost of Rio de Janeiro state, as well potential threats to the species. Sampling was carried out in September and December 2018, monthly in 2019 and between January to March and September to December in 2020. Overall, 70 breeding records were compiled, between 1997 and November 2021, being 64 from WikiAves in all regions of Brazil, four records from eBird in São Paulo state (in 2021) and two records in literature (one from São Paulo state, in 2007 and one from Rio de Janeiro in 2012). In RJNP, 44 nests were identified being 34 active, with an average of 3.5 eggs per nest, and overall 118 eggs were measured. The main materials used to build the nests were the saltmarsh plant and mud. Around 60% of nests were degraded or predated. Predation was the main cause of egg loss. Successful nests (with chicks or hatching signs) represented 26% of the total nests monitored. This study reports the first information on the biometry of the species' eggs and nests, confirming the northern coast of Rio de Janeiro state as a nesting area for the species.

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