Every month there's an outing to the Botanical Garden, Century Park, Gongqing Forest Park, Changfeng Park, Daning Lifehub and other spots.

Gu believes he has spotted more than 100 bird species.

Shanghai once had 370 bird species according to "Shanghai Birds, Resources and Their Habitat" (1993).

The book collected sightings since the 19th century, including those by foreign birdwatchers.

It included museum specimens.

More than two-thirds of the city birds are migratory. Since 1993, there have been sightings of 10 more species, including the sandhill crane, white crane and long-billed Dowitcher.

The city's total of species today, 137, "isn't a lot, but for a city like Shanghai it's not bad," says Yuan from the wildlife bureau.

Because of its location, Shanghai is neither the best breeding spot nor the best over-wintering spot.

"Most birds are just passing through, they're just in transit," says Yuan.

That's because the best breeding areas are north of the Qinling Mountains (a major mountain range located mainly in north-central China's Shaanxi Province) while the best place to spend the winter is considerably south of the Yangzte River.

Shanghai on the Yangzte is just a stop-over.

Improved habitats such as the wetlands in Chongming Island and Baoshan District welcome more migratory birds, but the number of resident birds is a more direct index for the environment in Shanghai.

Providing a good environment for resident avians is much more difficult than simply planting trees.

Most resident birds prefer a habitat with many different kinds of trees including tall trees and bushes, and they like nearby water and space to fly.

Before Shanghai began to go green, there were first "green deserts" -- just lawns or areas with one or a few kinds of trees. The birds didn't come.

Now the greening strategy is changing and the number and variety of resident birds are slowly increasing.

For more information of, or to join in, the Shanghai Wild Bird Society, check www.shwbs.org.

Birds of Shanghai

Common blackbird

It's 12-29 centimeters long, with a long tail. The adult male has glossy black plumage, a yellow eye-ring and an orange-yellow bill. The female is soot brown.

It breeds in woods and gardens, building a neat, mud-lined, cup-shaped nest. It is omnivorous, eating many insects, earthworms, berries and fruit. It may be a resident or migratory.

It usually lays three to five eggs.

Chinese bulbul

It's a medium-sized (19cm) noisy bird with a black crown, white throat and undersides (the vent is the underside around the tail), grayish back and wings.

It feeds on berries, soft fruits and vegetables, as well as insects that they sometimes capture in the air.

The nest is cup-shaped, usually in the fork of a bush; it's made of coarse grasses and may be lined with fine grasses, leaves and flowers, as well as cotton, paper and manmade materials.

The clutch is usually three to four eggs.

Spotted dove

It's 28-32 centimeters long, with a long tail.

The back, wings and tail are pale brown, heavily spotted with buff. The head and underparts are pinkish, shading to pale gray on the face and lower belly. There is a black neck patch.

It eats grass, seeds, grain and vegetation. It breeds all year round with nests commonly found in trees, eaves of buildings or the ground.

A clutch is two eggs.

Tree sparrow

Sparrows were one of the "four pests" - the others are rats, flies and mosquitoes - eliminated in the Four Pests Campaign in the 1950s.

They were targeted because they ate grain and thus were believed to harm agriculture. Many other birds were also killed.

Tree sparrows are the most common birds in Shanghai. It's 12-14 centimeters long, with a wingspan of around 21 centimeters.

The crown and neck are chestnut with a black ear patch on each white cheek. The throat is black. The upper body is light brown, streaked with black, and the brown wings have two distinct narrow white bars. The sexes have similar plumage.

It builds untidy nests in natural cavities, under eaves or in the old nests of magpies. A typical clutch is five or six eggs that hatch in about two weeks.

It eats mostly seeds, but also insects in the mating season.

(Shanghai Daily February 24, 2009)