St James's Park and The Green Park are London's most central Royal Parks. They are covered together here because they are close to each other, separated only by The Mall.
The Green Park is easily accessed from its northern end from Green Park underground station. It consists of a large area of open grassland, with lines of trees — mainly London Plane — along some of the paths. The park has no undergrowth, no scrubby areas, no flower beds and no water. Consequently, the diversity of birdlife is poor. One of the few species to breed here is Mistle Thrush, although they are not present all year round. Intensive watching in the 1960s showed that the few hawthorns in the centre of the park offer the best place for migrants, such as Lesser Whitethroat, to turn up. At the southern end of the park is Buckingham Palace and opposite that lies St James’s Park.
The dominant feature of St James’s Park' is its lake, complete with two islands (Duck Island and West Island). It is this that adds variety to the park's avifauna. The many trees in the park are mainly London Plane but also include a couple of Alders, some Weeping Willows and exotic pines. Additionally, some good scrubby patches with holly bushes are attractive to migrants, such as the Firecrest seen on 9 October 2001. Reed Bunting, Lesser Whitethtroat, Common Whitethroat and Spotted Flycatcher were all recorded in 2015. Common Whitethroat recorded again 2016. 'Regular migrants include Chiffchaff, Willow Warbler and Blackcap, which can be heard singing in spring, usually on the islands. Two small reedbeds in the lake attract summering Reed Warblers which bred in 2015. A Kingfisher was recorded almost every day for 6 months from 1st September 2014 and another has been present since 4th July 2016.
A captive wildfowl collection on the lake includes the famous – and very popular – White Pelicans. One is a free-flying bird that was "rescued" from the Essex coast and released into the park. Other species include Black Swan, Red-crested Pochard and Eider, all of which breed. The presence of these captive birds attracts all manner of wildfowl. Tufted Duck and Pochard are resident here and breed and their numbers increase in winter when they may be joined by occasional Shoveler. Canada, Greylag and Egyptian Goose can usually be seen here.
At times it can be difficult to determine which birds are wild. For example, fully-winged geese such as White-fronted Goose, Pink-footed Goose and Emperor Goose have all been seen in recent years, but are presumably escapes.
Legitimate wild birds seen include 'Slavonian Grebe, Great Crested Grebe, Little Grebe, Grey Heron, Cormorant, Black-headed Gull, Common Gull, Lesser Black-backed Gull, Great Black-backed Gull, Herring Gull , Mediterranean Gull, Coot and Moorhe'n. No raptors breed in the park but Kestre'l and Sparrowhawk are seen regularly while Peregrine is regular and Common Buzzard increasingly so at passage time. A Red Kite was seen in 2015 and 2016. S'wifts are often seen in summer but hirundines are only seen on passage and then only on a few days each year. Common Tern is occasionally recorded but as fly-over only. Grey Wagtail is often seen and occasionally Pied Wagtail too. Stock 'Dove can be found if looked for among the ubiquitous Pigeons. Waders are rarely noted, with just a couple of records of Common Sandpiper (2 birds together in July 2014 and one bird July 2016) and Woodcock (including one in November 2014 and October 2015) in recent years. Breeding birds include Blackbird, Wren, Dunnock, Robin, Goldcrest, Blue Tit, Coal Tit and Great Tit. A Spotted Flycatcher was recorded on just one day in 2015 as was a Lesser and a Common Whitethroat . A Reed Bunting was recorded once in 2015. Flocks of Goldfinch and Greenfinch liven up many a lunchtime and may be joined by Siskin in Autumn and Winter. A Lesser Redpoll recorded in Spring 2016. Great Spotted Woodpecker and (rarely) Green Woodpecker can be seen. Jackdaw was recorded twice in the Park in 2015 where Starlings also feed, though the large roost of yesteryear is long gone. Tawny Owl may use the Park as they breed in nearby Buckingham Palace Gardens.
Flocks of Redwing and Fieldfare can be seen flying over in Winter and in hard Winters feeding on the lawns or on the trees. A Water Rail took up temporary residence at the end of 2015.
Bats can be seen around the Lake at dusk.
'Butterflies recorded include: Painted Lady, Red Admiral, Peacock, Comm'a, Small Tortoiseshell, Small Copper, Gatekeeper, Meadow Brown, Holly Blue, Common Blue, Brimstone, Small, Large and Green Veined White.
Moths include Burnet Companion and Vapourer
The Park is very popular with tourists and with office workers at lunchtime but the majority of the birds recorded have been in the afternoon even at its busiest.
For additional information see the Royal Parks website.