Listening to Macaronesian seabirds

The Seabird Macaronesia Sound (SMS) LIFE4BEST project is being implemented in Madeira (Madeira island) and Azores (Santa Maria, Graciosa, São Jorge, and Flores islands) archipelagos – marine hotspots and key biodiversity areas for seabirds in Macaronesia.

Both archipelagos enclose a total of nine Procellariiform breeding species: Cory’s shearwater Calonectris borealis, manx shearwater Puffinus puffinus, Audubon’s shearwater Puffinus lherminieri, Bulwer’s petrel Bulweria bulwerii, white-faced storm-petrel Pelagodroma marina and band-rumped petrel Hydrobates castro, as well as three endemic species – Monteiro’s storm-petrel Hydrobates monteiroi, Zino’s petrel Pterodroma madeira and Deserta’s petrel Pterodroma deserta. The Portuguese Macaronesian archipelagos harbor the world’s biggest breeding population of Cory’s shearwater, Europe’s largest colony of white-faced storm-petrel and Bulwer’s petrel, and the world’s biggest breeding colony of Audubon’s shearwater.

The last census and seabird population status review for the Azores dates from 1996-1998 (Monteiro et al., 1999; Groz & Monteiro, 1999 and Groz et al., 2005). Therefore, it is seriously outdated and there is no baseline data on which to support conservation actions and the definition of Key Biodiversity Areas for seabird species. The situation in Madeira is even more concerning. There is no information about the main populations of breeding seabirds on Madeira island.

The Seabird Macaronesian Sound (SMS) project aims to update the information on seabird distribution and population size in the Macaronesian islands of Azores and Madeira, targeting 26 potential colonies and five seabird species – manx shearwater (LC), Audubon’s shearwater (LC), band-rumped petrel (LC), Monteiro’s storm-petrel (VU), and Zino’s petrel (EN), by using a low-cost and standardized passive acoustic methodology. This project aims to improve and update baseline data by filling the knowledge gaps, in an effort to enhance conservation measures and define relevant action plans, but also to promote a better understanding of biodiversity and ecosystem services. Also, the low-cost passive acoustic methodology can be replicated and standardized to Macaronesia or outermost regions in order to evaluate the environmental status of a given species, assess populations and to ensure adaptation to threats such as climate change. Since seabirds are long-lived species, apex marine predators, philopatric (tendency of an organism to stay in or habitually return to a particular area), colonial breeders, and they forage in a wide variety of marine ecosystems, these species can be used as management units acting as ocean and land sentinels.

The passive acoustic methodology used in this project is based on the study carried out by the researcher Luís Monteiro between 1996-1998, and enables users to identify the distribution and estimate species abundance via vocalizations. Sampling periods are defined based on the breeding season (incubation and hatching of the offspring in asynchronous species) and counts are made every half hour after sunset until 00:00, following the information collected by previous autonomous recording units (frequency of visits to the colonies through the vocalization rate) placed in the main accessible colony sectors.

The number of calls is recorded by an experienced observer (30 minutes, in 5-minute periods, corresponding to 6 periods) and a recorder in order to calibrate the recorded information (30 minutes of continuous recording, with an equalizer to reduce wind effect), coupled with a unidirectional amplifier at a fixed point. To minimize the difference in detection between different observers, the experienced observer is the same at all sampling points, thus standardizing the information collected between the various islands due to variations in habitat/colonies and environmental variables. The methodology was adapted according to weather conditions, such as wind and rain, as well as the moon phase (census must be carried out preferably on a new moon, decreasing moon or on foggy nights due to a greater number of vocalizations / increased activity).

In total, 7 islands in the Azores and Madeira have been monitored to detect the presence of the target species of the project. In close synergy with the LIFE IP Azores Natura Project and the EElabs project on Corvo Island, the team expanded the sampling area on two additional islands (Corvo and Faial, in Azores). So far, 60 sampling points were surveyed following the defined methodology (except for Graciosa Island, where the weather conditions postponed the census, carried out only in December – though still within the period of incubation and species breeding season). Some preliminary data shows that Hydrobates castro was detected in 46 sampling points (in varying numbers) either in transit or indicating the possible presence of new breeding colonies at some of the sampling points.

It should also be noted that Puffinus lherminieri was detected during the census, which was expected given the asynchrony of the species. By the beginning of the breeding season, prospectors, immature or non-breeding animals can be observed in the colonies from August and with greater regularity in December. In Santa Maria, Puffinus puffinus was detected (breeding season from February to August), also indicating the presence of prospectors in at least one of the points. The species was previously detected on this island, but only in the Vila’s Islet (regularly since 2017 and with confirmed breeding in 2007, Bried et al., 2007), but with no records of detection and breeding on the island of Santa Maria.

In Madeira, during the first field season, no positive records of Hydrobates castro (winter population) were obtained. Preliminary results of the census performed in March and April indicate the presence of Puffinus puffinus and Puffinus lherminieri in 3 different locations (Puffinus lherminieri was heard four times in two different sampling points and Puffinus puffinus only once, so far). The field work campaign will continue until the end of May in both archipelagos.

Project outreach has been one of the key factors to increase knowledge about Macaronesian seabirds, with several mini documentaries on national and regional televisions, publications in the national, regional, and local press and, the major highlight, on the Facebook group “Aves Marinhas da Macaronésia” that counts 1600 members who follow conservation and protection work that is being carried out on Macaronesian seabirds.

Due to the COVID-19 pandemic, the project team had to face certain extra challenges, such as flight limitations between islands and extended curfews. Schools have been closed often over the past months and, with the delay on the regular curricula, they have not been open to environmental education activities. This resilient team has embraced the challenge and has already adapted its lectures to digital formats, such as webinars and remote meetings, and has already obtained interesting results!

Over the past two months, things have improved and, with the reopening of schools, the team has made a great effort on the awareness campaign. So far, 15 lectures, workshops and webinars were held, which already reached around 300 people (from first graders to the elderly). Of the many activities offered in environmental education, the seabirds’ themes were the most requested by schools and associations (9 presentations in total).  

The project team hopes that LIFE4BEST SMS will deliver a noteworthy contribution to biodiversity conservation by updating the existing data on seabird species protected by the Birds Directive and by fulfilling several EU targets: protect species and habitats; update and assess species to complete the Natura 2000 network and indirectly help improve management; enforce the implementation of EU laws and Directives; raise awareness; and deliver more consistent monitoring and reporting by implementing a low-cost, standardized and innovative methodology that is also replicable.

For more information about this exciting project, you can follow the Facebook group at and visit the website