The Guardian • Issue #2044

Bird vagrancy: an indicator of global climatic changes

The White Ibis is now so numerous in the beaches and parks that they are called “bin chickens.” Photo: Anna Pha

In October 2022 a young Bar-Tailed Godwit broke a world record by flying non-stop from Alaska to Ansons Bay, Tasmania, 13,560 km in 11 days. Scientists in Alaska had attached a 5G satellite tag in order to track the species’ migration patterns.

Eric Woehler, from Birdlife Tasmania, said the bird had probably lost “half or more of its body weight” during its continuous day and night flight. The flight was dangerous for the little bird as the species is unable to land on water – they don’t have webbed claws.

A vagrant bird is a bird which is outside its normal wintering and breeding areas. Other vagrants attracted the media, when birds normally found in Asia turned up in Gippsland and in western Victoria.

A species never seen before in Australia, the Long-Billed Dowitcher, was spotted at Lake Tutchewop, Swan Hill. Vagrant Aleutian Terns appeared in NSW. In January 2022 a Narcissus Flycatcher, native to the Korean Peninsula, Japan, the Philippines and Borneo, was spotted at a roadhouse near Port Hedland WA.

In April 2021 a Nordmann’s Greenshank was spotted in Cairns, Qld. Affectionately called Nordy, the lone bird had flown off course during its usual migration from Russia to South-East Asia. Never before spotted on the east coast of Australia, “Nordy” is very rare, with little more than 1000 left in the wild.

One of Australia’s most distinctive bird vagrants is the Musk Duck which has been spotted several times in the Brisbane wetlands.

The records of the Birds Australia Rarities Committee show that since the 1990s there have been an increasing number and variety of vagrant birds. Amongst these are the Spotted Whistling Duck found in Weipa, Qld.; the Pheasant-tailed Jacana in Paraburdoo, WA; the Laughing Gull in Triabunna, Tasmania; and the Blue Rock Thrush in Noosa, Qld.

In south-eastern Australia on average the first arrival of migrant birds has advanced by 3.5 days per decade since 1960, with departures delayed by 5.1 days per decade. The Rufous Whistler now spends significantly longer periods at its breeding grounds in Australia.

Vagrant birds are increasingly being recorded outside of their normal geographic range. A recent study of an Asian songbird showed that it was establishing a new migration route because of the loss of habitats. Vagrancy numbers have increased in Australia, New Zealand, Antarctica, the United Kingdom, the USA, and elsewhere. According to Bird Life International, climate change has had a significant change in Australian bird distribution and abundance, especially for migratory birds.

While a boon for bird watchers, it raises the question of why bird vagrancy continues to increase? Are changes in migratory routes a direct response to species facing global climate changes and habitat losses? In the past ornithologists argued that birds spotted outside of their normal range, vagrants, had been lost due to storms, changes in ocean currents, or navigation errors. It is now increasingly obvious that climatic changes are playing an important part by altering resource availability, resulting in changes in bird distribution patterns.

Between 1977 and 2006 land birds, such as the Pacific Baza and the Pied Butcherbird, have moved 300 km further south. Such changes are having a deleterious impact on many Australian bird species, especially those with restricted habitats.

The Tooth-billed Bowerbird, which is endemic to high altitude rainforests in the Atherton Tableland of north-east Qld, is especially susceptible. Species that occupy low-lying islands, such as the critically endangered Orange-bellied Parrot, will be threatened by rising sea levels.

It is not only in Australia where habitat loss and pollution have caused the mass death of birds. In 2012 thousands of Pelicans were found washed up on shore in Peru. Over-fishing of the important anchovy areas had led to mass starvation.

Other factors in massive bird losses include, industrial pollution, oil spills, farming techniques and bird eradication policies. Millions of dead fish are washed up onshore from chemical spills and plastics around the world.

Thousands of songbirds died in 2020, in south-western USA, due to long-term starvation and unseasonably cold weather. Birds fell dead out of the sky due to air pollution, and a large number of migratory birds were found dead in Colorado, the result of habitat loss after massive brush fires and the emission of toxic compounds. Such occurrences are now common, worldwide.

Birds are more than part of our environment; they are an indicator of how our environment is changing and how much our climate has changed over the past sixty years. Birds require a suitable climate, food supply, nesting sites, and the need to feel safe while eating or breeding.

A damaged ecosystem forces birds to seek new territory or die from starvation. Property development has destroyed bird feeding areas in estuaries, mangrove swamps, beaches, mud flats, and farmland to such a degree that the difference can be noted in changing bird distribution patterns. Birds are forced to migrate.

The early explorers of Australia saw huge flocks of birds flying overhead or at feeding sites. The disappearance of such numbers is an indication of how European settlement has destroyed the landscape, reducing suitable ecosystems across the continent, leading to numerous species now being endangered.

Long-term monitoring has revealed an up to 90 per cent decline in many bird species in Australia. The Australian government has now listed the Far Eastern Curlew, Curlew Sandpiper and Great Knot as Critically Endangered, the level below extinction. The Red Knot and Lesser Sand Plover are listed as Endangered and the Greater Sand Plover as Vulnerable.

In the 1960s beaches around Brisbane had flocks of Seagulls and Pelicans and nearby Curlews, Cockatoos and Willy Wagtails. Sadly, this has changed. I saw my first Brush Turkey at the University of Queensland in 2010. This is a tropical bird, yet today they are common throughout Brisbane and Sydney. The White Ibis is now so numerous in the beaches and parks that they are called “bin chickens.” The loss of their normal feeding areas has forced birds to find their food amongst humans.

A number of species of migrating birds fly from Alaska and Siberia during the northern winter to feed in Australia and New Zealand during our summer. Two million birds, consisting of 36 species of waterbirds, migrate to Australia. Another sixteen species visit occasionally.

These migratory waterbirds include species such as Plovers, Sandpipers, Stints, Curlews, and Snipes. Many of these birds fly to Moreton Bay in southeast Qld. Its biodiversity is dependent on the health of the creeks and foreshores, which deteriorate under the constant expansion of urban and industrial areas.

Each year 50,000 migratory shorebirds arrive during their non-breeding season, our summer. They range from the large Far Eastern Curlew to the tiny Red-Necked Stint. These shorebirds arrive exhausted and need to eat as much food as possible to put on the weight needed to return to the Arctic, six months later. Any disturbance while they eat (low tide), or rest (high tide), impacts their ability to gain weight. Councils have placed signage around walking tracks and BBQ areas for the public to not disturb the wildlife, and indicating the route along which these birds travel every year.

Councils, dependent on increased income from growing house numbers and seaside holiday accommodation, allow developers to clear beach areas and bulldoze swamp lands for building estates.

The coastal regions of Australia are facing a contiguous barrage of environmental destruction that eradicates traditional feeding and nesting areas for birds and other wildlife. This is the cost of placing profits above the environment.

The present fines do little to stop the nefarious activities of certain corporations. Unlawful land clearing has penalties of $600,000 per breach, yet local governments appear reluctant to enforce them. Corporations do illegal tree clearing because they are rarely punished under the present development-first attitude of governments. These same corporations donate to governments at all levels to ensure their projects are passed. Property developers are among the biggest industry donors.

According to the Centre for Public Integrity, between 1999 and 2019, the industry donated more than $54 million. Donations are not always in cash. They may involve tickets to events, or membership of clubs, where developers have easy access to politicians to ensure the “right” decisions are made. The impact of governments and property developers continues to worsen the situation for our precarious native and birdlife, already suffering from the impacts of climatic changes.

Further Reading:: Graham Pizzey and Frank Knight. 2012. The Field Guide to the Birds of Australia. 9th ed. Sydney. HarperCollins Publishers.
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