Avian malaria may be behind drastic decline of London’s House Sparrows

London’s House Sparrows have plummeted by 71% since 1995, with new research suggesting avian malaria could be to blame.

Once ubiquitous across the capital city, the sudden, and unexplained decline of the iconic birds led a team from ZSL, the RSPB, the British Trust for Ornithology (BTO) and the University of Liverpool to investigate if parasite infections were involved.

Researchers collected data between November 2006 and September 2009 at 11 sites across London. Each site was centred around a single breeding colony and spaced at least four kilometres apart to ensure that birds from different groups didn’t mix. The team estimated changes in bird numbers by counting the mature males and took tiny blood and faecal samples from sparrows, carefully caught and soon released, to monitor infection rates and severity.

Of the 11 colonies studied, seven were declining. On average 74% of sparrows carried avian malaria – a strain that only affects birds - but this differed between groups with some as high as 100%. However, it was infection intensity (i.e. the number of parasites per bird) that varied significantly and was higher on average in the declining colonies.

Former ZSL Institute of Zoology researcher and lead author Dr Daria Dadam, now of the BTO, said: “Parasite infections are known to cause wildlife declines elsewhere and our study indicates that this may be happening with the House Sparrow in London. We tested for a number of parasites, but only Plasmodium relictum, the parasite that causes avian malaria, was associated with reducing bird numbers.”

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House sparrows staging a comeback, survey suggests

5 April 2019 at 12:02am

House sparrows appear to be staging something of a comeback after suffering major declines, the Big Garden Birdwatch suggests.

Results from the survey, run every year since 1979 by the RSPB which asks volunteers to count the birds in their garden or local park during a weekend in January, showed a mixed picture this year.

Sightings of some of the smallest garden birds were lower than last year, with long-tailed tits down by 27% and wrens by 17% after being seen in large numbers in 2018.

Populations of both species may have been hit by last year’s severe cold weather brought by the Beast from the East, which is likely to have hit smaller birds hardest, but experts said it was too early to say if it was a one-year blip or the start of a trend.

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House sparrows overtake starlings as most spotted garden bird in Northern Ireland

Marie Louise McConville

29 March, 2018 01:00

House sparrows have overtaken starlings as the number one bird spotted in gardens in Northern Ireland, according to the annual RSPB Big Garden Birdwatch.

Now in its 39th year, the annual Birdwatch is a chance for people of all ages to count the number of birds that visit their garden, helping the Royal Society for the Protection of Birds (RSPB) build up a picture of how they are doing.

Following the survey in January, which saw 420,000 people take part around the UK - 15,000 of whom were in Northern Ireland - it was found that there had been a surge in sightings of goldfinches, long-tailed tits and coal tits, and other smaller garden birds.

House sparrows remain at the top of the UK-wide Big Garden Birdwatch rankings with more than one million sightings throughout the weekend.

In addition, it was found that house sparrows have knocked starlings off their perch for the top spot in gardens across Northern Ireland.

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House sparrow decline linked to air pollution and poor diet

City sparrows suffer from more stress than their country cousins, find Spanish researchers, especially during breeding season

Date:  October 3, 2017

Source:  Frontiers

Summary:

House sparrows are well-adapted to living in urban areas, so it is surprising their numbers have fallen significantly over the past decades. An investigation into this worrying trend finds that sparrows living in urban areas are adversely affected by pollution and poor nutrition. The study also finds the birds suffer more during the breeding season, when resources are needed to produce healthy eggs.

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House sparrow decline linked to air pollution and poor diet

October 3, 2017

Despite being well-adapted to urban life, house sparrow numbers are falling. A study in open-access journal Frontiers in Ecology and Evolution finds that compared to sparrows living in the country, urban-dwelling birds show clear signs of stress linked to the toxic effects of air pollution and an unhealthy diet. This could have health implications for people living in cities.

"We find that house sparrows living in the city are suffering from more stress than those living in the countryside, and we link this to differences in air quality and diet," says Amparo Herrera-Dueñas, who completed this work in collaboration with the Department of Zoology and Physical Anthropology at the Complutense University of Madrid, Spain.

"It is particularly bad for urban birds during the breeding season when they are torn between allocating resources towards fighting the toxic effects of pollution or towards laying healthy eggs, both of which aren't helped by their poor diet."

She adds, "If our cities are unhealthy for birds, which is what our study is suggesting, then as their neighbors we should be concerned because we are exposed to the same environmental stressors as house sparrows."

Stress measured in urban, suburban and rural sparrows

Herrera-Dueñas and her colleagues used a non-invasive method to sample the blood of hundreds of sparrows from rural, suburban and urban areas around the Iberian Peninsula in Spain.

"We took a small blood sample from each bird, according to its weight and physical condition, and released them unharmed," she explains. The samples were analyzed for signs of oxidative stress, which can be used to measure how much an environmental stressor, such as pollution, is weakening the bird's natural defenses.

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Endangered garden birds continuing to decline in the UK, RSPB survey shows

Starlings, house sparrows and other threatened garden birds have suffered a further decline in their numbers over the past year, new figures show.

The results from the RSPB's annual Big Garden Birdwatch (BGBW),based on half a million people counting birds in their gardens over a weekend in January, also showed an increase in the species that are not commonly seen in back gardens, such as fieldfares and jays, after a freezing start to the year drove them out of the countryside in search of food.

Numbers of starlings, a "red-listed" species of conservation concern which dropped to a record low in last year's birdwatch, declined by a further 16% this year.

House sparrows – also endangered – fell by 17% on 2012 figures, while bullfinches and dunnock numbers also fell, by 20% and 13% respectively. While green finches have declined by nearly 21% since last year.

Martin Harper, the RSPB's conservation director, said: "We know from the many people who take part in Big Garden Birdwatch every year that garden birds are incredibly precious to us and connect us to nature every day … but several of our familiar and best-loved species have been declining at alarming rates over the 34 years that the RSPB has been running the birdwatch and this year's results show a continuing decline."

The starling, famous for its winter "murmurations" involving up to hundreds of thousands of birds, has seen a steady decline in numbers since the BGBW survey began in 1979. Losses have been linked to the loss of traditional, established farming pastures, where experts believe that intensively farmed land makes it more difficult for birds to find their favourite food – the cranefly larvae that live in undisturbed soil.

House sparrows have experienced a rapid recent decline, particularly in urban and suburban environments: greater London lost seven out of 10 sparrows between 1994 and 2001. The causes remain largely unknown, with everything from cats to air pollution being blamed.

"The decline of these two species is part of a long-term trend and nothing to do with the cold weather," said RSPB spokeswoman Wendy Johnson. "Starlings have gone down 82% since we started the survey and house sparrows by 63%. Bullfinches and dunnocks haven't declined overall in the same way as sparrows, starlings and songthrushes, however they are amber-listed species and we are concerned because they have suffered declines this year and over the last few years."

Continued: http://www.guardian.co.uk/environment/2013/mar/28/rsbp-garden-birdwatch-survey

House Sparrows

Bamboo nests have been placed at Coimbatore Zoo by the members of Vaagai Foundation to encourage nesting. Photo: S Siva Saravanan.

The house sparrows that once chirruped around in large numbers are now spotted rarely. “Blame it on high-rise buildings, lack of greenery, and radiation from the increasing number of cell phone towers. Development has shooed the little birds away from our neighbourhood,” says M. Sanjai Gandhi, chairman of Vaagai Foundation. It spreads awareness on rainwater harvesting, and environment conservation.

The Foundation is trying to bring many birds back. It has placed bamboo nests at various locations in the city, especially where there is greenery, to attract the birds. One of its first stops has been at the Coimbatore Zoo. More than 10 bamboo nests have been placed for the love birds to nest and breed. “As there are no trees, birds have no space to build nests. We want to encourage people to place the bamboo nests at their homes too,” says Sanjai. The small bamboo nests, they say, provides a comfortable nesting ground for a number of birds such as the finches, munias, babblers, and bee eaters. The nests can be kept on terraces, windows and compound walls.

Members of the foundation also plan to distribute open nests to attract crows and mynas. “We want to make nests for the thookanam kuruvi too from coir and coconut husks, and place them on trees in our neighbourhood,” he adds. Besides Ramanathapuram, Ramnagar and Gandhipuram in Coimbatore, the bamboo nests have made their way to places as far as Chennai, Kodaikanal and Dindigul.

“There was a time when there were sparrows in their hundreds. They would chirrup at the break of dawn, and it was our wake-up alarm,” remembers. S.R. Azhagappan, secretary of Vaagai Foundation.

Continued:  Read on:  http://www.thehindu.com/life-and-style/society/a-home-for-the-birds/article4034627.ece