Zino's Petrel
Encyclopedia
The Zino's Petrel or Freira, Pterodroma madeira, is a small seabird
in the gadfly petrel
genus
which is endemic to the island of Madeira
. This long-winged petrel has a grey back and wings, with a dark "W" marking across the wings, and a grey upper tail. The undersides of the wings are blackish apart from a triangle of white at the front edge near the body, and the belly is white with grey flanks. It is very similar in appearance to the slightly larger Fea's Petrel
, and separating these two Macaronesia
n species at sea is very challenging. Zino's was formerly considered to be a subspecies
of the Soft-plumaged Petrel
, P. mollis, but they are not closely related, and Zino's was raised to species status because of differences in morphology
, calls, breeding behaviour and mitochondrial
DNA
. It is Europe's most endangered seabird, restricted to a few ledges high in the central mountains of Madeira.
Zino's Petrel nests in burrows which are visited only at night, to the accompaniment of their haunting calls. The single white egg is incubated by both adults, one sitting during the day while the other feeds on fish and squid at sea. Eggs, chicks and adults have been subject to predation by introduced cats and rats, and in the past have been taken for food by local shepherds. Predator control, and other measures such as the removal of grazing animals which trample the burrows, has enabled the population to recover to 65–80 breeding pairs; it remains Endangered
on the IUCN Red List
. However, conservation efforts had a major setback in August 2010 when fires killed three adults and 65% of the chicks.
in the Desertas Islands
, and in the Cape Verde
archipelago were long considered to be subspecies of the Southern Hemisphere Soft-plumaged Petrel, P. mollis, but mitochondrial DNA analysis, and differences in size, vocalisations, breeding behaviour, showed that the northern birds are not closely related to P. mollis, and that the Bermuda Petrel
or Cahow may be the closest relative of the Macaronesian birds. Sangster recommended establishing Zino's Petrel on Madeira and Fea's Petrel on the Desertas and Cape Verde as full species, and the species split was accepted by the Association of European Rarities Committees
(AERC) in 2003.
Sangster estimated that the two Macaronesian species diverged at the end of the Early Pleistocene
, 850,000 years ago, although the methodology used to establish this time scale has subsequently been questioned. An analysis of feather lice
taken from Fea's Petrels, Pterodroma feae deserti, from Bugio Island, and from Zino's Petrels from the Madeiran mainland showed that there were marked differences between the two seabirds in terms of the parasites they carried, suggesting that they have long been isolated, since lice can normally only be transferred through physical contact in the nest. The species on Zino's Petrel are most similar to those of the Bermuda Petrel, whereas Fea's Petrel's lice are like those of Caribbean and Pacific Pterodroma species. This suggests that despite the close physical proximity of the two species of gadfly petrel found in the Madeiran archipelago, they may have arisen from separate colonisations of mainland Madeira and, later, the Desertas Islands
. Although their reproductive isolation has allowed the separate evolutionary development of the two species, genetic evidence shows the three Macaronesian petrels are each others closest relatives.
The petrels breeding in the high central mountains of Madeira were first recorded in 1903 by German naturalist and priest Ernst Johann Schmitz
, who failed to realise that they were different from the Fea's Petrels he had seen in the Desertas. The species was formally described as a race of Soft-plumaged Petrel by Australian amateur ornithologist
Gregory Mathews
in 1934. Following the recognition of the Madeiran birds as a full species, they were named after the Portuguese ornithologist, Paul Alexander Zino
, who was instrumental in their conservation during the latter half of the twentieth century. The genus name Pterodroma is derived from Greek πτερον, pteron, "a wing", and δρομος, dromos, "running", and refers to the bird's swift erratic flight. The specific madeira refers to the island on which it breeds. The Portuguese name Freira means "nun"; the inhabitants of Curral das Freiras
(Nun's Valley) near the breeding site claimed that the nocturnal wailing of the petrels in the breeding season were the calls of the suffering souls of the nuns. The sisters had taken refuge in the valley from attacks on the island by French pirates in 1566 that lasted for 15 days.
Pterodroma petrel remains dated at between 60,000 and 25,000 years BP
were found in two cave sites in Gibraltar. They consist of a more abundant form similar in size to Zino's, and a larger, less common type. It is uncertain whether they represent the site of a former breeding colony, or are the result of a seabird wreck in which storms blow birds inland. They do suggest, however, that members of the genus were formerly more widespread.
or Great Shearwater
, with a fast flight; in strong winds it shears high above the surface with angled wings. Nothing is known of the fresh juvenile plumage or the moult sequence, and ageing birds is currently not feasible.
This species is very similar in appearance to the Fea's Petrel
, but is smaller. The size difference and lighter flight may not be apparent at sea, especially with lone birds, but a recent study helped to clarify other useful features. Zino's has a diagnostically small, delicate, often rather long and slender bill, which may be obvious in the most slender-billed examples, which are probably mostly females, but can be difficult to determine in larger-billed, probably adult male, birds. Another useful feature is a large whitish panel on the underwing. The wing panel is exclusive to Zino's but is only shown by 15% of the birds. Zino's has a more rounded wing tip, but P. feae deserti sometimes shows a rounded wing tip, so this feature is not diagnostic. Previously suggested criteria such as head, upperwing and flank patterns were found to be inconclusive. Off the eastern United States and the Azores, both Macronesian petrels are easily distinguished from the larger Bermuda Petrel by that species' upperparts, which are uniformly dark but for a pale grey rump.
This species at its breeding sites gives a long mournful call like the hooting of a Tawny Owl
, and a much less frequent sound like the whimpering of a pup. It is silent at sea. The breeding calls are very similar to those of Fea's Petrel, and Bretagnolle's analysis of the calls of the Soft-plumaged Petrel complex led him to suggest in 1995 only a two-way species split, with the northern forms madeira, feae and deserti all as subspecies of Fea's Petrel.
expeditions to the Madeira archipelago in 2008, 2009 and 2010 each had sightings of a Pterodroma petrel (possibly the same bird) with largely white underwings, but upperwings like Zino's or Fea's. This plumage does not correspond to any known Pterodroma species. It may have been an unusual variant of Zino's but this is unlikely since no similar bird has been seen amongst the more than 100 caught at the nest. It may alternatively be a single aberrant individual, a hybrid or an unknown taxon from Madeira or elsewhere. No conclusion is possible on current knowledge.
, but grasses may also be present. It nests at heights above 1650 m (5400 ft). It was formerly more widespread, since subfossil
remains have been found in a cave in eastern Madeira, and on nearby Porto Santo Island
. The breeding ledges have to be inaccessible to introduced goats so that they remain rich in endemic flora. The vegetation ensures that there is sufficient earth on the ledges to allow the birds to burrow and make their nests, and trampling by grazing animals reduces the soil cover.
This petrel is only present in Madeiran waters during the breeding season. Its distribution at sea during the rest of the year is poorly known due to the rarity of the species and the difficulty of separating it from other Pterodroma petrels at sea. Birds identified as either Zino's or Fea's have been recorded from both sides of the North Atlantic, and in Ireland and Britain there has been a large increase in the number of reports, perhaps because global warming brings increasing numbers of tropical species into temperate waters. The timing of the reports, mainly in late spring and summer in the western North Atlantic, and in late summer and early autumn in the east, has suggested that birds follow a clockwise route around the North Atlantic after leaving their breeding sites. However, the few birds that have been identified with certainty have all been Fea's. Zino's Petrel may have a similar strategy, since preliminary results from geolocation studies indicate widespread dispersal over the North Atlantic central ridge during the breeding season, and migration towards the Brazilian coast in the non-breeding period. Pterodroma petrels have been recorded in the Canary Islands
and the Azores
on surprisingly few occasions; a claim of possible Zino's from South Africa is now thought to be erroneous.
about 85 days later in late September and October. This petrel is strictly nocturnal at the breeding sites to avoid predation by gull
s. It stays 3–5 km (2–3 mi) offshore during the day, coming to land in darkness. It calls from about 30 minutes after nightfall until dawn, including on moonlit nights.
This species mates for life, and pairs return to the same burrow year after year. The single egg is not replaced if lost. This is a long-lived species: one bird has returned to its burrow for ten consecutive years, and the lifespan is estimated to be about 16 years. The age of first breeding is unknown, but assumed to be four or more years. Despite the proximity of the breeding sites, Zino's and Fea's Petrels have never been found at each others' nesting areas, and Zino's is not known to hybridise with any other species.
s, the bioluminiscent
fish Electrona risso
and small crustacean
s. Like other small petrels, Zino's does not normally follow ships.
, is a rodent hunter. Other than bats, there are no native land mammals on Madeira, although there are a number of introduced species, two of which will take birds or chicks. These are Brown Rats
and feral domestic cat
s. Even the high mountain nest sites of the Zino's Petrel are not safe from these adaptable predators, ten adults being killed by cats in 1990. Feather lice
found on Zino's Petrels include Trabeculus schillingi, Saemundssonia species and an unnamed species of Halipeurus.
in the early 1940s, presumably attracted there by lights, but the species was not seen again until 1969. In 1969, Paul Zino played a tape of Fea's Petrel from Bugio to a shepherd from Curral das Freiras; he immediately recognised the call, and led the researchers to the remaining nesting area. Predation by introduced rats meant that breeding success in the small population was low, and no young at all fledged in 1985. The Freira Conservation Project was founded in 1986 with the aim of increasing the population of Zino's Petrel by controlling rats and human interference; the control was extended to cats after the mass predation of 1990.
There are now 130–160 known individuals (65–80 breeding pairs) confirmed to breed on just six ledges. There may be some disturbance from visitors at night and from the construction of a NATO radar station on the summit of Mount Areeiro, and in the longer term climate change may have an adverse effect, since all nests are within 1,000 m (3250 ft) of the top of the highest mountain in the breeding area. Formerly, shepherds collected nestlings for food, and egg collectors have raided burrows. Currently, the main threats continue to be predation of eggs and chicks by rats, and of nesting adults by feral cats, although at much reduced levels due to trapping.
Zino's Petrel is protected under the EU's Wild Birds Directive, and its breeding sites lie within the Parque Natural da Madeira
national park
. Following the purchase of about 300 ha (740 acres) of land around the main breeding site, all livestock has been removed from the breeding areas, allowing the vegetation to recover, although breeding still only occurs on ledges that were never accessible to grazing animals. The research and predator control by the Freira Conservation Project and the national park which started in 1986 was expanded in 2001 with additional EU funding. The increase in productivity (29 chicks fledged in 2004) meant that this species was downgraded from Critically Endangered
to Endangered on the IUCN Red List in 2004. Its population appeared to be stable or increasing slightly up to the summer of 2010.
A disaster struck the colony on 13 August 2010, when a forest fire swept through the breeding site killing three adults and 25 of the 38 chicks. The fire destroyed the vegetation and several nesting burrows. Conservation action to protect the 13 remaining chicks included removing dead birds and burnt vegetation, reinforcing the surviving nests, and setting poison bait for rats around the now exposed nest sites. In the longer term, the action plan includes the provision of artificial burrows, seed dispersal to help the vegetation recover, and the use of anti-erosion materials.
Seabird
Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...
in the gadfly petrel
Gadfly petrel
The gadfly petrels are seabirds in the bird order Procellariiformes. These medium to large petrels feed on food items picked from the ocean surface....
genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
which is endemic to the island of Madeira
Madeira
Madeira is a Portuguese archipelago that lies between and , just under 400 km north of Tenerife, Canary Islands, in the north Atlantic Ocean and an outermost region of the European Union...
. This long-winged petrel has a grey back and wings, with a dark "W" marking across the wings, and a grey upper tail. The undersides of the wings are blackish apart from a triangle of white at the front edge near the body, and the belly is white with grey flanks. It is very similar in appearance to the slightly larger Fea's Petrel
Fea's Petrel
Fea's Petrel is a small seabird in the gadfly petrel genus, Pterodroma. It was previously considered to be a subspecies of the Soft-plumaged Petrel, P. mollis, but they are actually not closely related at all. However, P. feae is very closely related to Zino's Petrel and Deserta's Petrel, two...
, and separating these two Macaronesia
Macaronesia
Macaronesia is a modern collective name for several groups of islands in the North Atlantic Ocean near Europe and North Africa belonging to three countries: Portugal, Spain, and Cape Verde...
n species at sea is very challenging. Zino's was formerly considered to be a subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
of the Soft-plumaged Petrel
Soft-plumaged Petrel
The Soft-plumaged Petrel is a species of seabird in the Procellariidae family.-Distribution:It breeds on islands in the Southern Hemisphere, nesting on Tristan da Cunha, Gough Island, the Prince Edward Islands, Crozet Islands, Macquarie Island, and on the Antipodes Islands of New Zealand. Small...
, P. mollis, but they are not closely related, and Zino's was raised to species status because of differences in morphology
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
, calls, breeding behaviour and mitochondrial
Mitochondrion
In cell biology, a mitochondrion is a membrane-enclosed organelle found in most eukaryotic cells. These organelles range from 0.5 to 1.0 micrometers in diameter...
DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
. It is Europe's most endangered seabird, restricted to a few ledges high in the central mountains of Madeira.
Zino's Petrel nests in burrows which are visited only at night, to the accompaniment of their haunting calls. The single white egg is incubated by both adults, one sitting during the day while the other feeds on fish and squid at sea. Eggs, chicks and adults have been subject to predation by introduced cats and rats, and in the past have been taken for food by local shepherds. Predator control, and other measures such as the removal of grazing animals which trample the burrows, has enabled the population to recover to 65–80 breeding pairs; it remains Endangered
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
on the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
. However, conservation efforts had a major setback in August 2010 when fires killed three adults and 65% of the chicks.
Taxonomy
The gadfly petrels in the genus Pterodroma are seabirds of temperate and tropical oceans. Many are little-known, and their often similar appearance have caused the taxonomy of the group to be rather fluid. The forms breeding in Macaronesia on Madeira, BugioBugio Island
Bugio Island is one of the Desertas Islands, a small chain of islands in the archipelago of Madeira, located to the southeast of the island of Madeira....
in the Desertas Islands
Desertas Islands
The Desertas Islands are a small Portuguese archipelago, located about 25 km to the southeast of Ponta de São Lourenço, the eastern tip of the island of Madeira, the whole chain located roughly between Madeira and the Canary Islands.-Geography:...
, and in the Cape Verde
Cape Verde
The Republic of Cape Verde is an island country, spanning an archipelago of 10 islands located in the central Atlantic Ocean, 570 kilometres off the coast of Western Africa...
archipelago were long considered to be subspecies of the Southern Hemisphere Soft-plumaged Petrel, P. mollis, but mitochondrial DNA analysis, and differences in size, vocalisations, breeding behaviour, showed that the northern birds are not closely related to P. mollis, and that the Bermuda Petrel
Bermuda Petrel
The Bermuda Petrel, Pterodroma cahow, is a gadfly petrel. Commonly known in Bermuda as the Cahow, a name derived from its eerie cries, this nocturnal ground-nesting seabird is the national bird of Bermuda, and a symbol of hope for nature conservation. It was thought extinct for 330 years...
or Cahow may be the closest relative of the Macaronesian birds. Sangster recommended establishing Zino's Petrel on Madeira and Fea's Petrel on the Desertas and Cape Verde as full species, and the species split was accepted by the Association of European Rarities Committees
Association of European Rarities Committees
The Association of European Rarities Committees is a co-ordinating and liaison body for the bird rarities committees of Europe and other nearby countries.It was created in 1993 at a meeting of European rarities committees on the German island of Heligoland....
(AERC) in 2003.
Sangster estimated that the two Macaronesian species diverged at the end of the Early Pleistocene
Early Pleistocene
Calabrian is a subdivision of the Pleistocene Epoch of the Geologic time scale. ~1.8 Ma.—781,000 years ago ± 5,000 years, a period of ~.The end of the stage is defined by the last magnetic pole reversal and plunge in to an ice age and global drying possibly colder and drier than the late Miocene ...
, 850,000 years ago, although the methodology used to establish this time scale has subsequently been questioned. An analysis of feather lice
Louse
Lice is the common name for over 3,000 species of wingless insects of the order Phthiraptera; three of which are classified as human disease agents...
taken from Fea's Petrels, Pterodroma feae deserti, from Bugio Island, and from Zino's Petrels from the Madeiran mainland showed that there were marked differences between the two seabirds in terms of the parasites they carried, suggesting that they have long been isolated, since lice can normally only be transferred through physical contact in the nest. The species on Zino's Petrel are most similar to those of the Bermuda Petrel, whereas Fea's Petrel's lice are like those of Caribbean and Pacific Pterodroma species. This suggests that despite the close physical proximity of the two species of gadfly petrel found in the Madeiran archipelago, they may have arisen from separate colonisations of mainland Madeira and, later, the Desertas Islands
Desertas Islands
The Desertas Islands are a small Portuguese archipelago, located about 25 km to the southeast of Ponta de São Lourenço, the eastern tip of the island of Madeira, the whole chain located roughly between Madeira and the Canary Islands.-Geography:...
. Although their reproductive isolation has allowed the separate evolutionary development of the two species, genetic evidence shows the three Macaronesian petrels are each others closest relatives.
The petrels breeding in the high central mountains of Madeira were first recorded in 1903 by German naturalist and priest Ernst Johann Schmitz
Ernst Johann Schmitz
Ernst Johann Schmitz was a German naturalist, ornithologist, entomologist and Roman Catholic priest who settled in Madeira in the late 1870s, serving as vice chancellor of the Funchal Seminary from 1891 to 1898, and again from 1902 to 1908, becoming a naturalised Portuguese citizen. From 1898 to...
, who failed to realise that they were different from the Fea's Petrels he had seen in the Desertas. The species was formally described as a race of Soft-plumaged Petrel by Australian amateur ornithologist
Ornithology
Ornithology is a branch of zoology that concerns the study of birds. Several aspects of ornithology differ from related disciplines, due partly to the high visibility and the aesthetic appeal of birds...
Gregory Mathews
Gregory Mathews
Gregory Macalister Mathews CBE was an Australian amateur ornithologist.Mathews made his fortune in mining shares, and moved to England around 1900....
in 1934. Following the recognition of the Madeiran birds as a full species, they were named after the Portuguese ornithologist, Paul Alexander Zino
Paul Alexander Zino
Paul Alexander Zino was a Portuguese ornithologist after whom Zino's Petrel is named....
, who was instrumental in their conservation during the latter half of the twentieth century. The genus name Pterodroma is derived from Greek πτερον, pteron, "a wing", and δρομος, dromos, "running", and refers to the bird's swift erratic flight. The specific madeira refers to the island on which it breeds. The Portuguese name Freira means "nun"; the inhabitants of Curral das Freiras
Curral das Freiras
Curral das Freiras , is a civil parish in the municipality of Câmara de Lobos in the Portuguese archipelago of Madeira. In 2001 the popylation was just over 1673 residents, in an area that covers 25.07 km² of the interior mountain range of the island, in the shadow of Pico do Arieiro and Pico Ruivo...
(Nun's Valley) near the breeding site claimed that the nocturnal wailing of the petrels in the breeding season were the calls of the suffering souls of the nuns. The sisters had taken refuge in the valley from attacks on the island by French pirates in 1566 that lasted for 15 days.
Pterodroma petrel remains dated at between 60,000 and 25,000 years BP
Before Present
Before Present years is a time scale used in archaeology, geology, and other scientific disciplines to specify when events in the past occurred. Because the "present" time changes, standard practice is to use AD 1950 as the origin of the age scale, reflecting the fact that radiocarbon...
were found in two cave sites in Gibraltar. They consist of a more abundant form similar in size to Zino's, and a larger, less common type. It is uncertain whether they represent the site of a former breeding colony, or are the result of a seabird wreck in which storms blow birds inland. They do suggest, however, that members of the genus were formerly more widespread.
Description
This long-winged petrel is 32–34 cm (12.5–13.4 in) long with an 80–86 cm (31–34 in) wingspan, and an average weight of 290 g (10.3 in). It has a grey back, grey wings with a dark "W" marking across them, and a grey upper tail. The undersides of the wings are blackish apart from a triangle of white at the front edge near the body, and the belly is white with grey flanks. The head has a mottled whitish-brown forehead, a dark cap, and a dark spot below and behind the brown eye. The bill is black and the legs are flesh pink, the colour continuing onto the first third of the feet, the rest of the toes and webs being black-brown. It gives the general impression of a small Cory'sCory's Shearwater
The Cory's Shearwater is a large shearwater in the seabird family Procellariidae.This species breeds on islands and cliffs in the Mediterranean, with the odd outpost on the Atlantic coast of Iberia. The nest is on open ground or among rocks or less often in a burrow where one white egg is laid,...
or Great Shearwater
Great Shearwater
The Great Shearwater is a large shearwater in the seabird family Procellariidae. Its relationships are unclear. It belongs in the group of large species that could be separated as genus Ardenna ; within these, it might be allied with the other black-billed, blunt-tailed species Short-tailed...
, with a fast flight; in strong winds it shears high above the surface with angled wings. Nothing is known of the fresh juvenile plumage or the moult sequence, and ageing birds is currently not feasible.
This species is very similar in appearance to the Fea's Petrel
Fea's Petrel
Fea's Petrel is a small seabird in the gadfly petrel genus, Pterodroma. It was previously considered to be a subspecies of the Soft-plumaged Petrel, P. mollis, but they are actually not closely related at all. However, P. feae is very closely related to Zino's Petrel and Deserta's Petrel, two...
, but is smaller. The size difference and lighter flight may not be apparent at sea, especially with lone birds, but a recent study helped to clarify other useful features. Zino's has a diagnostically small, delicate, often rather long and slender bill, which may be obvious in the most slender-billed examples, which are probably mostly females, but can be difficult to determine in larger-billed, probably adult male, birds. Another useful feature is a large whitish panel on the underwing. The wing panel is exclusive to Zino's but is only shown by 15% of the birds. Zino's has a more rounded wing tip, but P. feae deserti sometimes shows a rounded wing tip, so this feature is not diagnostic. Previously suggested criteria such as head, upperwing and flank patterns were found to be inconclusive. Off the eastern United States and the Azores, both Macronesian petrels are easily distinguished from the larger Bermuda Petrel by that species' upperparts, which are uniformly dark but for a pale grey rump.
This species at its breeding sites gives a long mournful call like the hooting of a Tawny Owl
Tawny Owl
The Tawny Owl or Brown Owl is a stocky, medium-sized owl commonly found in woodlands across much of Eurasia. Its underparts are pale with dark streaks, and the upperparts are either brown or grey. Several of the eleven recognised subspecies have both variants...
, and a much less frequent sound like the whimpering of a pup. It is silent at sea. The breeding calls are very similar to those of Fea's Petrel, and Bretagnolle's analysis of the calls of the Soft-plumaged Petrel complex led him to suggest in 1995 only a two-way species split, with the northern forms madeira, feae and deserti all as subspecies of Fea's Petrel.
"Snowy-winged petrel"
The Hadoram ShirihaiHadoram Shirihai
Hadoram Shirihai is an Israeli ornithologist and writer.-Biography:Shirihai grew up in Jerusalem where he became fascinated with birds when he was 13 and spent much time documenting shorebird behaviour, raptor breeding biology and participating in bird migration surveys...
expeditions to the Madeira archipelago in 2008, 2009 and 2010 each had sightings of a Pterodroma petrel (possibly the same bird) with largely white underwings, but upperwings like Zino's or Fea's. This plumage does not correspond to any known Pterodroma species. It may have been an unusual variant of Zino's but this is unlikely since no similar bird has been seen amongst the more than 100 caught at the nest. It may alternatively be a single aberrant individual, a hybrid or an unknown taxon from Madeira or elsewhere. No conclusion is possible on current knowledge.
Distribution and habitat
Zino's Petrel is endemic to the main island of Madeira, where it breeds on inaccessible and well-vegetated ledges in the central mountains between Pico Areeiro and Pico Ruivo. The typical ledge plants are endemic hemicryptophytess and ChamaephytesSubshrub
A subshrub or dwarf shrub is a short woody plant. Prostrate shrub is a similar term.It is distinguished from a shrub by its ground-hugging stems and lower height, with overwintering perennial woody growth typically less than 10–20 cm tall, or by being only weakly woody and/or persisting...
, but grasses may also be present. It nests at heights above 1650 m (5400 ft). It was formerly more widespread, since subfossil
Subfossil
Subfossil refers to remains whose fossilization process is not complete, either for lack of time or because the conditions in which they were buried were not optimal for fossilization....
remains have been found in a cave in eastern Madeira, and on nearby Porto Santo Island
Porto Santo Island
Porto Santo Island is a Portuguese island northeast of Madeira Island in the North Atlantic Ocean; it is the northernmost and easternmost island of the archipelago of Madeira, located in the Atlantic Ocean west of Europe and Africa.- History :...
. The breeding ledges have to be inaccessible to introduced goats so that they remain rich in endemic flora. The vegetation ensures that there is sufficient earth on the ledges to allow the birds to burrow and make their nests, and trampling by grazing animals reduces the soil cover.
This petrel is only present in Madeiran waters during the breeding season. Its distribution at sea during the rest of the year is poorly known due to the rarity of the species and the difficulty of separating it from other Pterodroma petrels at sea. Birds identified as either Zino's or Fea's have been recorded from both sides of the North Atlantic, and in Ireland and Britain there has been a large increase in the number of reports, perhaps because global warming brings increasing numbers of tropical species into temperate waters. The timing of the reports, mainly in late spring and summer in the western North Atlantic, and in late summer and early autumn in the east, has suggested that birds follow a clockwise route around the North Atlantic after leaving their breeding sites. However, the few birds that have been identified with certainty have all been Fea's. Zino's Petrel may have a similar strategy, since preliminary results from geolocation studies indicate widespread dispersal over the North Atlantic central ridge during the breeding season, and migration towards the Brazilian coast in the non-breeding period. Pterodroma petrels have been recorded in the Canary Islands
Canary Islands
The Canary Islands , also known as the Canaries , is a Spanish archipelago located just off the northwest coast of mainland Africa, 100 km west of the border between Morocco and the Western Sahara. The Canaries are a Spanish autonomous community and an outermost region of the European Union...
and the Azores
Azores
The Archipelago of the Azores is composed of nine volcanic islands situated in the middle of the North Atlantic Ocean, and is located about west from Lisbon and about east from the east coast of North America. The islands, and their economic exclusion zone, form the Autonomous Region of the...
on surprisingly few occasions; a claim of possible Zino's from South Africa is now thought to be erroneous.
Breeding
Zino's Petrel breeds two months earlier than the Fea's Petrel's on Bugio, only 50 km (30 mi) away. The birds return from sea to their breeding grounds in late March or early April and courting occurs over the main breeding area during the late evening and early morning hours. The nest is a shallow burrow or old rabbit tunnel up to 140 cm (55 in) long in thick soil on vegetated ledges. The length of the burrow is related to the age of the pair that uses it, young birds making shorter tunnels, which are extended in subsequent years. The oval white egg is laid from mid-May to mid-June in a chamber at the end of the burrow and incubated for 51–54 days, each parent alternating between sitting on the nest and feeding at sea. The young fledgeFledge
Fledge is the stage in a young bird's life when the feathers and wing muscles are sufficiently developed for flight. It also describes the act of a chick's parents raising it to a fully grown state...
about 85 days later in late September and October. This petrel is strictly nocturnal at the breeding sites to avoid predation by gull
Gull
Gulls are birds in the family Laridae. They are most closely related to the terns and only distantly related to auks, skimmers, and more distantly to the waders...
s. It stays 3–5 km (2–3 mi) offshore during the day, coming to land in darkness. It calls from about 30 minutes after nightfall until dawn, including on moonlit nights.
This species mates for life, and pairs return to the same burrow year after year. The single egg is not replaced if lost. This is a long-lived species: one bird has returned to its burrow for ten consecutive years, and the lifespan is estimated to be about 16 years. The age of first breeding is unknown, but assumed to be four or more years. Despite the proximity of the breeding sites, Zino's and Fea's Petrels have never been found at each others' nesting areas, and Zino's is not known to hybridise with any other species.
Feeding
Zino's Petrel, like its relatives, feeds on small squid and fish. The vomited stomach contents of one bird contained cephalopodCephalopod
A cephalopod is any member of the molluscan class Cephalopoda . These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot...
s, the bioluminiscent
Bioluminescence
Bioluminescence is the production and emission of light by a living organism. Its name is a hybrid word, originating from the Greek bios for "living" and the Latin lumen "light". Bioluminescence is a naturally occurring form of chemiluminescence where energy is released by a chemical reaction in...
fish Electrona risso
Electrona risso
The Electrona risso or Chubby Flashlight Fish is a species of lanternfish in the family Myctophidae. This marine fish is found at depths of 90-820 m. The males can reach 8.2 cm in length and have32-34 vertebrae. This species is sexually mature from 5.9 cm long. It is oviparous with planktonic...
and small crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s. Like other small petrels, Zino's does not normally follow ships.
Predators and parasites
Their nocturnal approach to the breeding sites means that Zino's Petrels avoid the attentions of gulls or diurnal raptors, and the only owl on the island, the Barn OwlBarn Owl
The Barn Owl is the most widely distributed species of owl, and one of the most widespread of all birds. It is also referred to as Common Barn Owl, to distinguish it from other species in the barn-owl family Tytonidae. These form one of two main lineages of living owls, the other being the typical...
, is a rodent hunter. Other than bats, there are no native land mammals on Madeira, although there are a number of introduced species, two of which will take birds or chicks. These are Brown Rats
Brown Rat
The brown rat, common rat, sewer rat, Hanover rat, Norway rat, Brown Norway rat, Norwegian rat, or wharf rat is one of the best known and most common rats....
and feral domestic cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
s. Even the high mountain nest sites of the Zino's Petrel are not safe from these adaptable predators, ten adults being killed by cats in 1990. Feather lice
Louse
Lice is the common name for over 3,000 species of wingless insects of the order Phthiraptera; three of which are classified as human disease agents...
found on Zino's Petrels include Trabeculus schillingi, Saemundssonia species and an unnamed species of Halipeurus.
Conservation status
Zino's Petrel has a very restricted range on the mountaintops of a single island, and is the most endangered European seabird. The birds, already confined to a limited area when discovered, were thought to be extinct by the mid-twentieth century. Two freshly fledged juveniles were found within the walls of the governor's palace in FunchalFunchal
Funchal is the largest city, the municipal seat and the capital of Portugal's Autonomous Region of Madeira. The city has a population of 112,015 and has been the capital of Madeira for more than five centuries.-Etymology:...
in the early 1940s, presumably attracted there by lights, but the species was not seen again until 1969. In 1969, Paul Zino played a tape of Fea's Petrel from Bugio to a shepherd from Curral das Freiras; he immediately recognised the call, and led the researchers to the remaining nesting area. Predation by introduced rats meant that breeding success in the small population was low, and no young at all fledged in 1985. The Freira Conservation Project was founded in 1986 with the aim of increasing the population of Zino's Petrel by controlling rats and human interference; the control was extended to cats after the mass predation of 1990.
There are now 130–160 known individuals (65–80 breeding pairs) confirmed to breed on just six ledges. There may be some disturbance from visitors at night and from the construction of a NATO radar station on the summit of Mount Areeiro, and in the longer term climate change may have an adverse effect, since all nests are within 1,000 m (3250 ft) of the top of the highest mountain in the breeding area. Formerly, shepherds collected nestlings for food, and egg collectors have raided burrows. Currently, the main threats continue to be predation of eggs and chicks by rats, and of nesting adults by feral cats, although at much reduced levels due to trapping.
Zino's Petrel is protected under the EU's Wild Birds Directive, and its breeding sites lie within the Parque Natural da Madeira
Parque Natural da Madeira
The Madeira Natural Park is a large biological reserve in Madeira with a unique endemic flora and fauna. It was created in 1982 to safeguard the natural heritage of the archipelago, and contains a number of endangered species including global rarities such as Zino's Petrel...
national park
National park
A national park is a reserve of natural, semi-natural, or developed land that a sovereign state declares or owns. Although individual nations designate their own national parks differently A national park is a reserve of natural, semi-natural, or developed land that a sovereign state declares or...
. Following the purchase of about 300 ha (740 acres) of land around the main breeding site, all livestock has been removed from the breeding areas, allowing the vegetation to recover, although breeding still only occurs on ledges that were never accessible to grazing animals. The research and predator control by the Freira Conservation Project and the national park which started in 1986 was expanded in 2001 with additional EU funding. The increase in productivity (29 chicks fledged in 2004) meant that this species was downgraded from Critically Endangered
Critically Endangered
Critically Endangered is the highest risk category assigned by the IUCN Red List for wild species. Critically Endangered means that a species' numbers have decreased, or will decrease, by 80% within three generations....
to Endangered on the IUCN Red List in 2004. Its population appeared to be stable or increasing slightly up to the summer of 2010.
A disaster struck the colony on 13 August 2010, when a forest fire swept through the breeding site killing three adults and 25 of the 38 chicks. The fire destroyed the vegetation and several nesting burrows. Conservation action to protect the 13 remaining chicks included removing dead birds and burnt vegetation, reinforcing the surviving nests, and setting poison bait for rats around the now exposed nest sites. In the longer term, the action plan includes the provision of artificial burrows, seed dispersal to help the vegetation recover, and the use of anti-erosion materials.
External links
- Madeira Birds: Zino's Petrel