Verónica C. Neves

Status and Distribution of Fea's Petrel, Bulwer's Petrel, Manx Shearwater, Little Shearwater and Band-Rumped Storm-Petrel in the Azores Archipelago

-This paper reports the first comprehensive surveys of Feas Petrel (Pterodromafeae), Bulwers Petrel (Bulweria bulwerii), Manx Shearwater (Puffinus puffinus), Little Shearwater (Puffinus assimilis baroli) and two temporally-segregated forms of Band-rumped Storm-petrel (Oceanodroma castro) in the whole Azores archipelago, conducted from 1996 to 1998. Listening to nocturnal vocalizations was the main survey method. Breeding of Feas Petrel was not confirmed and new sites of Bulwers Petrel were not found (previous status: one site, 50 pairs), but previously undocumented colonies were identified for the remaining species. Manx Shearwater occurred in four colonies with 115-235 pairs (previous status: probable breeder), Little Shearwater occurred in 28 colonies with 840-1,530 pairs (previously: four locations, >150 pairs), hot-season Band-rumped Storm-petrels occurred in 5 colonies with 250-300 pairs (previously: two locations, 200 pairs) and cool-season Band-rumped Storm-petrels were found in eight locations with 665-740 pairs (previously: three locations, 600 pairs). Most colonies were confined to precipitous cliffs and islets, which may be a result of predation threats by introduced mammals. Although these surveys provided a valuable revision of the status and distribution for these species of conservation concern, further survey work is warranted and target areas are indicated. We discuss the potential and limitations of listening for nocturnal vocalizations as a method to survey and monitor shearwater and petrel populations in inaccessible habitats. Received 24 May 1999, accepted 8 July 1999.

Seabird Habitat Restoration on Praia Islet, Azores Archipelago

As on many other islands, most of the seabird species breeding in Portugal’s Azores archipelago are now restricted to tiny remnants of their former nesting range, owing in large part to the introduction of mammals by humans. Praia Islet, 0.12 km2 in size, is home to five seabird species, four of which fall under the European listing of “conservation concern.” Introduced rabbits (Oryctolagus cuniculus) on Praia had accelerated soil erosion through overgrazing, destroyed seabird nests, and competed for burrows with petrels. Restoration of seabird habitat on the islet began in 1995 and involved rabbit eradication, control of soil erosion, native plant reintroduction, and installation of artificial nests for common terns (Sterna hirundo), roseate terns (Sterna dougallii), and Madeiran storm-petrels (Oceanodroma castro). Rabbits were eradicated in 1997 using broadcast pellets containing poison. Since then, soil erosion has decreased, many of the reintroduced native plants have started to spread, and tern and Madeiran storm-petrel breeding numbers on the islet have increased by 1,548% and 43%, respectively. However, Praia Islet seabirds remain vulnerable owing to human recreational activities. This case study highlights the need to consider local conditions carefully when assessing restoration options to effect rapid mammal eradication. It also confirms the value of combining measures aimed at restoring native vegetation and improving seabird habitat quality with alien herbivore eradication.

Seabird mortality induced by land-based artificial lights

Artificial lights at night cause high mortality of seabirds, one of the most endangered groups of birds globally. Fledglings of burrow-nesting seabirds, and to a lesser extent adults, are attracted to and then grounded (i.e., forced to land) by lights when they fly at night. We reviewed the current state of knowledge of seabird attraction to light to identify information gaps and propose measures to address the problem. Although species in families such as Alcidae and Anatidae can be grounded by artificial light, the most affected seabirds are petrels and shearwaters (Procellariiformes). At least 56 species of Procellariiformes, more than one-third of them (24) threatened, are subject to grounding by lights. Seabirds grounded by lights have been found worldwide, mainly on oceanic islands but also at some continental locations. Petrel breeding grounds confined to formerly uninhabited islands are particularly at risk from light pollution due to tourism and urban sprawl. Where it is impractical to ban external lights, rescue programs of grounded birds offer the most immediate and employed mitigation to reduce the rate of light-induced mortality and save thousands of birds every year. These programs also provide useful information for seabird management. However, these data are typically fragmentary, biased, and uncertain and can lead to inaccurate impact estimates and poor understanding of the phenomenon of seabird attraction to lights. We believe the most urgently needed actions to mitigate and understand light-induced mortality of seabirds are estimation of mortality and effects on populations; determination of threshold light levels and safe distances from light sources; documentation of the fate of rescued birds; improvement of rescue campaigns, particularly in terms of increasing recovery rates and level of care; and research on seabird-friendly lights to reduce attraction.

Diet of Bulwer's Petrel (Bulweria bulwerii) in the Azores, NE Atlantic

Abstract. Studying the diet of top marine predators, such as seabirds, is important in understanding their place in the trophic network and effects of global climate change, but knowledge of the diet of several procellariiformes remains anecdotal. The diet of Bulwers Petrel (Bulweria bulwerii) in the Azores was studied over two consecutive years using stomach flushings from 85 birds. The frequency of occurrence of prey taxa (%0) was similar in both years (&khgr;2 = 5.396, d.f. = 5, p = 0.370), with squid being the most common. Fish and squid were of similar occurrence by number (%N) in the diet (49% and 51%, respectively) in 1998 but in 1999 fish were more numerous (62% against 38% for squid). Squid lower beaks from five families and fish otoliths from six families were identified, representing 20 taxa. The most abundant prey in both years were squid Pyroteuthis margaritifera and the mesopelagic fish Electrona risso. The maximum standard length offish and squid consumed was 7 cm and 11 cm, respectively. Given most of the identified prey are luminescent, the findings corroborate earlier studies suggesting Bulwers Petrel feed on small mesopelagic prey that migrate to the surface at night.

Banded Roseate Terns from different continents trapped in the Azores

Abstract Banded Roseate Terns (Sterna dougallii) trapped on nests in the Azores illustrate that, during the nonbreeding season, birds from the Azores are found on the coast of Africa in groups of Roseate Terns from northern Europe and on the coast of South America with birds from the northeastern U.S. and the Caribbean. One Roseate Tern, probably originally banded on a nest in a western Atlantic colony, suggests the possibility of gene flow between these colonies and the Azores.

A control taste aversion experiment on predators of roseate tern (Sterna dougallii) eggs

European starlings (Sturnus vulgaris) are responsible for high rates of egg predation at one of the main colonies of the endangered roseate tern (Sterna dougallii) in the Azores archipelago. Control taste aversion has been effective in controlling raven predation in a colony of California least tern (Sterna antillarum browni), but there is little quantitative information about its efficacy on other species of predators taking eggs. We conducted a control taste aversion experiment on yellow-legged gulls (Larus michahellis) and European starlings eating eggs of terns in a mixed colony of common (Sterna hirundo) and roseate terns in the Azores. We treated quail (Coturnix coturnix) eggs with methiocarb and deployed them in artificial nests in the tern colony. On the first experiment, conducted before the terns laid eggs, predation rates on quail eggs by yellow-legged gulls showed significant and rapid decrease after deployment of treated eggs. During the second experiment, after the terns had started laying, results were mixed. Although predation rates by European starlings on treated quail eggs decreased, predation rates on tern eggs did not. We conclude that control taste aversion using methiocarb-treated eggs is likely to reduce depredation by gulls but not starlings because of the need to pre-train the birds and the tendency of starlings to be attracted by the movement of adults, not the presence of nests.

Recovery in Punta Rasa, Argentina of Common Terns Banded in the Azores Archipelago, North Atlantic

Abstract We report the southernmost recoveries of Common Terns (Sterna hirundo) banded in the Azores archipelago, North Atlantic. Two birds banded as chicks and one bird banded as an adult were recovered at Punta Rasa, Argentina, adding support to the hypothesis of a regular movement of Common Terns between the Azores and the South American coast rather than to the African coast.

Are European starlings breeding in the Azores archipelago genetically distinct from birds breeding in mainland Europe

The European starling (Sturnus vulgaris) has recently been found to eat eggs of the endangered roseate tern (Sterna dougallii) in the Azores. Azorean starlings are considered an endemic subspecies (S. vulgaris granti), so we investigated how much genetic divergence has accumulated between the Azores and other European populations in order to assess whether lethal control measures might be possible, as previous experiments have found that taste aversion is not likely to be successful. For this purpose, we sequenced a region of the protein-coding mitochondrial gene ND2 for samples from six different populations. Of the 1,026 base pairs sequenced, 19 (1.7%) were variable and formed 15 different haplotypes. The Azores had high and significant genetic differentiation from all the other populations studied. Haplotype diversity was high in the mainland populations studied, ranging from 0.767 to 0.900, but there was no variation among the Azores samples, which were collected from a geographically broad region. Given the lack of genetic variability in the Azores birds and their abundance throughout the archipelago, lethal control on a local basis and as part of an integrated control plan can be seen as a reasonable measure to protect tern colonies.

The role of Malcolm Clarke (1930–2013) in the Azores as a scientist and educationist

Malcolm Roy Clarke (1930–2013) was a British teuthologist who made an important contribution to marine science in the Azores archipelago (Portugal). Malcolm started doing research in the Azores from 1980s onward, settling for residency in 2000 after retirement (in 1987). He kept publishing on Azorean cephalopods collaborating in 20% of the peer reviewed works focus- ing on two main areas: dietary studies; and the ecology of cephalopods on seamounts. Since his first visit in 1981, he was involved in the description of the dietary ecology of several cetaceans, seabirds, and large pelagic and deep-water fish. Using his own data, Malcolm revised the association of cephalopods with seamounts, updating and enlarging the different cephalopod groups according to species behaviour and ecology. Malcolm taught several students working in the Azores on cephalopods and beak identification, lecturing the Third International Workshop in Faial (2007). He empowered the recently established research community, by providing important contacts with foreign institutes and informal advice. He collaborated in the regional cetacean stranding network (RACA) and was an active member of the advisory board of the journal Arquipelago—Life and Marine Sciences . But the scientific role of Malcolm Clarke in the Azores went beyond his academic activities. In the last 10 years Malcolm and Dot Clarke dedicated themselves to building and running a museum on Pico Island, showing the biology of the sperm whale and its interaction with squid; a cultural and touristic legacy for future gen- erations to enjoy.

Migration routes and non-breeding areas of Common Terns (Sterna hirundo) from the Azores

Abstract We describe the migration routes and non-breeding areas of Common Terns (Sterna hirundo) from the Azores Archipelago, based on ringing (banding) recoveries and tracking of three birds using geolocators. Over 20 years, there have been 55 transatlantic recoveries of Common Terns from the Azores population: six from Argentina and 49 from Brazil. The three tracked birds migrated south in different months (August, September, November), but the northern migration was more synchronous, with all leaving in April. The birds were tracked to three areas of the South American coast: the male spent November—April on the northern Brazilian coast (13°N–2°S), whereas the two females first spent some time off central-eastern Brazil (4–16°S; one for 1 week, the other for 3 months) and then moved south to the coast of south-eastern Brazil, Uruguay and northern Argentina (24–39°S). Although caution is needed given the small sample size and errors associated with geolocation, the three tracked terns potentially travelled a total of ∼23 200 km to and returning from their non-breeding areas, representing an average movement of ∼500 km day−1. With the exception of Belém, in northern Brazil, and Lagoa do Peixe, in southern Brazil, the coastal areas used by the tracked birds were also those with concentrations of ringing recoveries, confirming their importance as non-breeding areas for birds from the Azores.