It is present at Trindade Island year-round (all months) and breeds in two well-defined periods with some overlap and apparent fidelity of individuals at one period. Nests are located in crevices and other cliff-cavities in the highest parts of Trindade (Antas 1991) as well as down to sea level. The peak times for breeding activities (laying) are October and April (F. P. da Fonseca Neto in litt. 2000). 

Pterodroma arminjoniana breeds on Trindade Islands off the coast of Espírito Santo, Brazil. It was considered abundant on Trindade in 1913 and 1986 (Murphy 1936, Filippini 1986). Surveys in the mid-1990s have indicated that the population on Trindade numbers 2,000-5,000 individuals (F. P. da Fonseca Neto in litt. 2000). The global population was estimated at 15,000 individuals (Brooke 2004), although recent estimates suggest the total may be as low as 1,130 breeding pairs (Luigi et al. 2008). Flocks have been noted flying around the Túnel, Pão de Açúcar, Farilhões and Crista de Galo peaks. Aerial courtship displays during daylight hours make the species very easily observeable, despite low abundance. From what was previously an unidentified Pterodroma species, the species was recently found to be breeding on Round Island, 22 km north of Mauritius, in the Indian Ocean (Brown et al. 2010). There have been confirmed sightings of several birds at sea in the central south Atlantic (490 nm northeast of Tristan da Cunha), off the Azores and a single sighting off Cape Verde Islands (Flood 2010). Geolocator trackings confirm they may regularly winter in the central North Atlantic (Ramos et al. in prep.). During breeding forage in a vast area around Trindade Island, from the Equator to 34°S, in deep waters. Apparently there is a staging area east of Trindade used by birds after breeding and before migration to North Atlantic Ocean (L. Bugoni and G.R. Leal unpubl. data). 

Conservation Actions Underway

Since 1967, Brazilian law has afforded protection to all seabirds by forbidding persecution, killing, colony disturbance and the use of bird by-products (Antas 1991). Goats and pigs denuded the island’s vegetation, likely degrading Trinidade Petrel breeding habitat, but were eradicated in 2004 and 1965 respectively (Alves et al. 2011, Kruger et al. 2018).

Conservation Actions Proposed

Designate the majority of Trindade as a federal reserve (Antas 1991) or national park (F. P. da Fonseca Neto in litt. 2000). Conduct an impact assessment before any construction on Trindade.