Scopoli's Shearwater at sea, photograph by John Borg

Mediterranean pelagic seabirds, like their big cousins, are continuously facing threats through human activities.  Accidental by-catch is not confined to the southern oceans, our three species of shearwaters are regularly caught on fishing lines in the Mediterranean.  Urbanization poses a threat to seabird colonies with light and sound pollution reducing their breeding success as well as the ever-increasing threat from alien predators.  Cats, rats and polecats all prey on the eggs and young of storm petrels and shearwaters.

The Maltese Islands, lying in the middle of the Mediterranean Sea, south of Sicily and north of the Libyan coast, host important colonies of Scopoli’s Calonectris diomedea and globally Vulnerable Yelkouan Puffinus yelkouan Shearwaters, as well as the largest known colony of Mediterranean Storm Petrels Hydrobates pelagicus melitensis.  Seabirds in Malta have been studied since the late 1960s through a bird ringing programme run by BirdLife Malta.  Since 1982, the breeding biology of these birds has been studied and the initial results showed that Malta had the lowest fledging success of Scopoli’s and Yelkouan Shearwaters in the region.

In 2006 the first of three EU Life projects was initiated and it focused on the largest colony of Yelkouan Shearwaters in Malta, at Rdum tal-Madonna on the north-east coast of Malta, a breeding colony of about 500 pairs.  This colony was facing numerous threats including predation on eggs and young by rats, to the extent that for almost fifteen years not a single chick fledged from any of the study nests.  Soon after the rat population was brought under control, the birds started increasing, new areas were colonized and the breeding success rapidly increased.  Furthermore, the tiny storm petrel started to visit these cliffs and some years later breeding was confirmed.

John Borg, National Museum of Natural History holds a Scopoli's Shearwater chick, photograph by Joe Sultana

Nowadays we have a much better understanding of where our birds go to feed and where they spend their post-breeding period.  Nevertheless, we still have numerous gaps in their life cycles. These birds are still facing serious threats at sea as well as from land.  In this respect, this year, the National Museum of Natural History, Mdina in collaboration with BirdLife Malta (EU LIFE seabird team) will be holding an exhibition commemorating World Albatross Day.  The exhibition will highlight the plight of these pelagic birds but will also look at the various advances in our knowledge in the life cycle of these birds.

The National Museum of Natural History, Mdina, photograph by John Borg

The exhibition will highlight the various threats such as accidental by-catch, predation by alien species, the effects of light and sound pollution as well as direct persecution and the important role of seabirds in the ecosystem through various displays.  We shall highlight various studies, methodologies and equipment used to monitor the shearwaters and storm petrels in the Maltese Islands over the last 50 years.

The Agreement on the Conservation of Albatrosses and Petrels (ACAP) will be commemorating World Albatross Day on 19 June – when the exhibition will open (and run to year end).  There are 31 different species listed in this agreement and while Malta and the rest of the Mediterranean has no albatross species, one species of procellariid; the Yelkouan Shearwater has been identified as a potential candidate for ACAP listing.

Work on the exhibition is now underway, display material for six showcases highlighting various topics are being chosen from the museum specimens, a life-sized fibre-glass model of a Wandering Albatross Diomedea exulans is being prepared by the museum artist and this will be the highlight of the exhibition.  A number of original photographs measuring about 1x1.5 m of different albatross species, as well as the three procellarids breeding within Malta, are at the printers; these will line the exhibition walls.

John J. Borg, Senior Curator, National Museum of Natural History, Mdina, Malta, 06 March 2020

Black Petrel, photograph by Edward Marshall

A banded globally and nationally Vulnerable Black Petrel/Takoketai Procellaria parkinsoni chick which fledged from Great Barrier Island/Aotea, New Zealand in 2001 was caught alive at sea on a vessel in Ecuador in 2007, according to a post on Wildlife Management International’s Facebook page.

“In Ecuador, the bird, then six years old, was disorientated when it was caught and didn’t want to fly, despite not having any injuries.  The crew cared for the bird for four days at sea, took it back to port for further care and additional food, and then released it alive when they returned to sea a couple of days later.”

The bird was recaptured for the first time at the Aotea study colony in a marked burrow near the summit of Mount Hobson/Hirakimata on 10 February 2020 at the age of 19 years, The bird was with another Black Petrel in the study burrow, so it is possible they may pair up and breed.

John Cooper, ACAP Information Officer, 05 March 2020

The globally Vulnerable Yelkouan or Mediterreanean Shearwater Puffinus yelkouan is endemic to the Mediterranean and Black Seas.  At risk from fisheries at sea and introduced predators and light pollution on land, it has been identified in the past as a potential candidate for listing by ACAP.

In response to its unfavourable conservation status the Faculty of Biology and the Biodiversity Research Institute (IRBio) of Spain’s University of Barcelona have commenced a new study of the biology and ecology of the shearwater at a global scale in the Mediterranean.  Collaborators in the project come from Crete, France, Greece, Italy, Malta, Spain, Tunisia and the United Kingdom, with funding from a Swiss foundation.  The project is being led by Raül Ramos, from the Department of Evolutionary Biology, Ecology and Environmental Sciences at the University of Barcelona.

“As part of the project, during 2020, the experts will study at the same time the space ecology (with miniaturised GPS) of five colonies of seabirds and will add data from previous studies to create a global evaluation gathering up to eight different populations in the Mediterranean.  The project will provide unpublished data to help define the main feeding areas for the Mediterranean Shearwater in the natural environment, the overlap between different populations, the nutrition pattern and areas of coincidence between fishing boats and seabirds.  Moreover, the experts will apply geolocation technology to see the migration patterns and hibernation areas of these birds (estimated to be in the Black Sea) in order to shape the annual distribution of each population and the general biological cycle of this endangered species.”

Read more here.

Reference:

Cooper, J. & Baker, G.B. 2008.  Identifying candidate species for inclusion within the Agreement on the Conservation of Albatrosses and Petrels. Marine Ornithology 36: 1-8.

John Cooper, ACAP Information Officer, 04 March 2020, updated 05 March 2020

The 40-year old Cory's Shearwater soon after collection

On 19 January 2020 a Cory's Shearwater Calonectris borealis with band No. 005286 was retrieved alive from Hobie Beach, Plettenberg Bay, Western Cape South Africa by Chanel Gemae Hauvette, Marine Research Technician with the environmental NGO Nature’s Valley Trust.  Despite the rehabilitation efforts by the Robberg Veterinary Clinic, the bird did not survive.  According to the Trust’s Facebook post, information from the Portuguese Ringing Scheme (Central Nacional de Anilhagem) via SAFRING is that the bird was banded (it seems most likely as a chick) on the Portuguese islTHTand of Selvagem Grande, Madeira Archipelago in the North Atlantic on 7 October 1979, making it a little over 40 years old.

The Cory's Shearwater on the beach before collection

In response to the post Marie Claire Gatt, ornithologist working on Cory's Shearwaters from Selvagem Grande, commented: “That's a great record!  Many seabirds live well into their 30s, but that lifestyle is exactly what places them so much at risk to environmental change induced by humans.  Cory's [Shearwaters] spend their first 7-9 years of life wandering the sea before they even attempt to breed for the first time.  This is usually when most mortalities happen, naturally from inexperience and infection, but now also from land stranding on their first flight as a result of light pollution, fishery bycatch, and intoxication.  If not enough youngsters survive into their adult years we eventually see a collapse in the population, but it could take so long to notice that not enough breeding birds are recruiting that for some species it could be too late. The Cory's population from Selvagem Grande has rebounded from intense harvesting of fat chicks which were considered a delicacy.  This activity has been illegal for a few decades now, and the population of Cory's numbers some 40 000 pairs nowadays.  This island is an absolute spectacle!”

This recovery represents a new record for longevity for the species, with the previous oldest recovery (as of May 2017) being given as 24 years and 10 months by EURING.  Not the oldest shearwater, however: EURING lists a Manx Shearwater Puffinus puffinus as reaching one month shy of 51 years of age.  In contrast, the oldest ACAP-listed Balearic Shearwater P. mauretanicus is recorded as being only 12 years old.  The oldest known seabird remains Wisdom, the 69+year Laysan Albatross Phoebastria immutabilis – still alive at last report.

John Cooper, ACAP Information Officer, 03 March 2020