Species today are at risk of going extinct at an unprecedented rate. However, can technology help us to save species from extinction? In this article Dr Oliver Padget tells us about his work with endangered seabirds, and some of the ways in which new technologies allow scientists and conservationists to do just this.
Seabirds comprise an evolutionarily diverse collection of species, coming from several taxonomic orders (albatrosses, shearwaters and petrels are of the order Procellarriifomes, for example, while puffins, skuas and gulls are members of the Charadriiformes). Seabird diversity exhibits the different ways that evolution has found to solve the problems presented by a pelagic (open sea) lifestyle – from the 25-gram storm-petrel to the seven-kilogram wandering albatross; from frigatebirds that never alight on water (they aren’t fully waterproof!), to guillemots diving more than 100 m. Sadly, the world’s seabirds are in precipitous decline.
Like all birds, seabirds lay eggs and so breed on land. During breeding, they must therefore commute to areas of the ocean where their food, mainly fish and squid, is plentiful. This creates several problems. First, anatomy suited to life at sea is not always practical for time spent on land. Most seabirds’ feet, for instance, are situated far back on their bodies, where they make excellent propellers or rudders during diving, but are poorly positioned for walking, making seabirds ungainly on land and vulnerable to predators. One solution adopted by some seabirds, such as shearwaters, is to breed only on remote islands where there are no ground predators. Another, adopted by auks like guillemots, is to breed on tiny ledges on steep sea cliffs.
A second problem is that anatomy suited to diving tends to be poorly suited to flying. Short wings allow some seabirds to ‘fly’ through the water to great depths but are inefficient in flight. Species such as puffins and guillemots, the latter of which can dive to depths of 100m, are therefore constrained to foraging close to their colony where commuting comprises only short flights. They avoid competition with other species by diving deeper rather than traveling further to forage on fish. At the other end of the scale, shearwaters, petrels and albatross have long wings which allow for efficient, high speed flight but make deep diving more difficult. Rather than diving deep, these species escape competition by exploiting prey over very large areas, sometimes to the extreme – the Deserta’s petrel, a small (400-gram) seabird breeding on remote islands off Madeira, routinely makes 10,000 km journeys across the Atlantic to search for food during 5-7 day-long trips.
At breeding colonies, seabirds are threatened by the introduction of ground predators and recent conservation efforts have focussed on eradication of rats and cats from remote islands. Threats to seabirds at sea, however, have until recently remained more of a mystery. Recent technological advances are helping scientists understand the at-sea factors driving declines. Miniaturised Global Positioning System (GPS) tags (the most modern weighing <10-grams) can be attached to seabirds and allow scientists to see where they go. Other miniaturised technologies, such as pressure sensors how deep they need to dive to catch the fish and squid that they rely on. Even heartrate monitors have been deployed to investigate how much energy seabirds use as they fly.
GPS tracking has revealed the areas of the oceans that many seabird species rely on to forage. For example, the Manx shearwater – a small seabird that breeds in here in the UK – congregate southwest of the Isle of Man, at an upwelling zone known as the Irish Sea Front. Identifying such foraging ‘hot spots’ in our oceans can help governments create Marine Protected Areas to protect important foraging grounds from over-fishing. Threats from bycatch in fisheries have been investigated too. There is evidence that setting long-lines at night would reduce bycatch of Europe’s most endangered seabird, the Balearic shearwater, since dive-loggers have shown that natural foraging occurs only during the day, and so shearwaters are less likely to be attracted to bait as it sinks during darkness. A recent study equipped wandering albatross in the Southern Ocean with GPS devices and radar sensors to detect illegal fishing. The data confirmed that Albatrosses were attracted to fishing vessels, but showed that over 1/3 of boats failed to declare officially their location to authorities – an explanation perhaps for why legally required by-catch mitigation measures are having a limited impact on albatross population declines.
Protecting foraging areas, eliminating ground predators at seabird colonies and reducing bycatch are the paths to solving seabird decline, but the picture is complicated. If seabird populations are to be saved, it will be these new technologies that shows us how.
Dr Oliver Padget is Junior Research Fellow in Biology at St John’s College, Oxford
|Procallariiformes||The taxonomic order of birds including the albatrosses, shearwaters and petrels|
|Charadriiformes||The taxonomic order of birds including auks (puffins, guillemots and razorbills), gulls and skuas|
|Pelagic||Far out at sea. E.g. pelagic seabirds are seabirds that spend time far away from land|
|Mustelid||A family of carnivorous mammals including weasels, stoats and minks|
|Kleptoparasitism||Stealing food from other animals|
|By-catch||Accidental capture of unintended species by fishers|
- Below is a figure from a scientific paper by Ventura et al (2020), showing the extraordinary foraging trips of Deserta’s petrels, which breed on islands off Madeira but travel to forage in the mid-Atlantic. Arrows on the figure show that the birds always travel in a clockwise direction. Why do you think Deserta’s petrels travel so far to forage? Why do you think they always travel clockwise? If you could put a datalogging device on a Deserta’s petrel what questions would you get it to record, what questions would like to answer and how do you think you’d go about doing that?
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