Many species are exploited beyond sustainable levels

Jim Enticott Commercial fishing effort overlaps with foraging hotspots for seabirds Zoom In

Unsustainable hunting for food or trapping for the cage-bird trade currently threatens hundreds of bird species. Bycatch of seabirds by fisheries is a major threat, particularly to albatrosses.

Exploitation of birds has become unsustainable

Humans have harvested and traded birds since time immemorial: for food, as pets, for cultural purposes and for sport. This use of nature is fundamental to the economies and cultures of many nations. Wild meat is not only a vital source of protein, but also generates valuable income for rural populations. However, expanding markets and increasing demand, combined with improved access and techniques for capture, are causing the exploitation of many species beyond sustainable levels. Over the last few decades, more than one-quarter of the world’s bird species have been recorded in international trade, with millions of individual birds traded each year.

Over-exploitation has already caused extinctions

Humans have already driven formerly numerous species to extinction through over-exploitation. An example is the Great Auk, once widely distributed across the North Atlantic, which was hunted for its feathers, meat, fat and oil, with specimen collecting the final cause of its extinction in about 1852. Another is the Carolina Parakeet, once wide-ranging and very common in the eastern USA, which was hunted for food, crop protection and the millinery trade, with the last captive bird dying in 1915. Overall, 50 species that have become extinct since 1500 (c.40% of the total) have been subject to over-harvesting.

Hunting and the cage-bird trade are major threats

Currently, nearly 30% of Globally Threatened Birds (GTBs) are threatened by over-exploitation, mainly through hunting for food and trapping for the cage-bird trade. Exploitation particularly affects some bird families, including parrots, pigeons and pheasants (see box 1), and certain countries, notably Indonesia and China (box 2). For some species that are especially highly sought after, overexploitation is causing huge declines in both numbers and range, and is known to be the most significant threat to them (box 3). For many other species, the total numbers harvested for international and domestic markets, and the effects of this exploitation, are still poorly known.

Growth of commercial fishing threatens seabirds

The growth of longline fishing around the world is an increasing threat to many seabird species. This is for two main reasons: areas where fishing is concentrated overlap with foraging hotspots for birds (box 4), and measures that prevent seabird capture are not yet widely used. Longline fleets set more than one billion hooks each year, catching and drowning some 300,000 seabirds as they scavenge the bait. Pirate fishing boats operating illegally in the southern oceans kill one-third, with the rest dying in legally licensed fisheries. This incidental bycatch is the single greatest threat to albatrosses. All 21 species are now classed as globally threatened or Near Threatened, largely because of interactions with fisheries.

Boxes: case studies and scientific analyses

Download SOWB pp.42–43 (PDF, 312 KB) containing the following:

1. Over-exploitation is a threat to many large and conspicuous bird species
Large numbers of parrots, pigeons and pheasants are threatened by over-exploitation

2. Unsustainable exploitation is most prevalent in Asia
In Indonesia and China, more than 50 GTBs are threatened by over-exploitation

3. Sought-after species face rapid declines
Two examples of heavily traded birds:
a) Philippine Cockatoo was once widespread and known from 52 islands, but there are recent records from just eight
b) Straw-headed Bulbul was once widespread in lowland areas of South-East Asia, but recent records are almost all from peninsular Malaysia, Sabah and Brunei

4. Commercial fishing effort overlaps with foraging hotspots for seabirds
Seabird at-sea ranges/satellite data comparison with numbers of hooks per grid square