Meet the woodland and heathland residents
Brownsea boasts a mosaic of wildlife habitats. These varying habitats are all incorporated within a small island and supports an amazing diversity of species rarely matched by places of a similar size.
There are eight priority habitats on Brownsea which include; lowland heathland, lowland dry acid grassland, wet woodland, reedbeds, saline lagoon, maritime cliff & slope, coastal saltmarsh, and coastal vegetated shingle. All these habitats sustain a huge wealth of wildlife from the larger mammals such as the sika deer, to the smaller residents such as the tiny pink crab spider.
The island’s ability to sustain such variety and wealth of wildlife is the basis for its designation as a Site Of Special Scientific Interest, or SSSI. The number of species is impressively demonstrated by the birds recorded on the island. Over a third of all species seen in Britain have been spotted on Brownsea and the island holds the record for the largest single flock of overwintering avocet and record numbers of spoonbill in the UK.
Brownsea’s biodiversity in a nutshell
Across the island there are some 334 different plant species that have been recorded, of which four are nationally scarce (NS) such as the shrubby seablite and a further five which have been given Red Data Book (RDB) sensitivity. There are 66 tree species, 143 lichens recorded with four NS and eight especially associated with old woodland. Some 79 species of mosses and liverworts have been recorded, as well as 46 species of marine algae.
The Brownsea woodland is one of only two places in southern England which is has a stable population of the protected red squirrel. Being an island, the resident squirrel population thrive with little threat from predators. The heathland also provides a special home for the amber listed nightjar and Dartford warbler.
Over on the lagoon, managed by The Dorset Wildlife Trust, there are a number of breeding birds who feature as 'amber' on the conservation watch list such as the Sandwich tern, oystercatcher and little egret. Over-wintering birds also include internationally important numbers of avocet and black-tailed godwit.
Other protected species who live on the island include water vole, three Nationally Scarce dragonfly species plus the brown long-eared and soprano pipistrelle bat.
A woodland home
The woodland on Brownsea is comprised of over 65 different tree species, most planted since the 1700s by a succession of owners. There are distinct areas of deciduous trees including native hardwood trees such as oak, beech, rowan and hazel and coniferous trees such as Scots, maritime and Monterey pines. The National Trust manages the woodland predominantly for the red squirrels, thinning out old trees and replanting new trees to create a good food source.
Our rare resident
There is a population of over 200 red squireels on the island who depend on the woodland to provide up to 80% of their food in order to survive, however their diet is quite diverse. Although most people think their main diet includes eating acorns, red squirrels cannot actually digest mature acorns, favouring only green or young ones. Instead their main diet comprises mostly of pine seeds.
The woodland is also home to a large herd of sika deer who were first introduced from Japan in the late 1800s. They are good swimmers and stags have been spotted swimming across the harbour to mate with the females on the island.
The rich variety of woodland also attracts small birds including coal, blue, great and long-tailed tits, great spotted woodpeckers, nuthatches and jays. The noctule bat (one of eleven species on the island) roosts in hollow trees and at night the tawny owl swoops out hunting for woodmice.
Until the late 1600s, much of Brownsea was probably heathland. From the early 1700s, a succession of owners began planting trees and growing crops, reducing the amount of heath. Today heathland is a scarce and fragmented habitat on the island and the National Trust has been restoring these areas back to life.
Lowland heathland, once a common part of the landscape in Southern England, is now rarer than the rainforest. 85% of it has been lost in the last 200 years due to farming and development. The National Trust manages the heathland on Brownsea Island carefully and every year, different areas of heath are cut to encourage bell and ling heather, the predominant vegetation, to grow.
A hidden world
For part of the year, the heath can appear dormant. Only when temperatures start to rise does the heath burst into a profusion of pink and purple flowers and awaken from its winter slumber. Even then, much of the activity takes place on or close to the ground, where many of the creatures are small, camouflaged and quick to hide.
Creatures such as spiders have adapted their survival strategies to help them live in this type of environment. For example, the tiny pink crab spider pounces on its prey, springing from heather flowers, rather than spinning a traditional web and others such as the wolf spider simply roam the heathland floor for its prey.
Spotlight on the Nightjar
The Brownsea heath is lucky enough to be home to two pairs of nightjar. These rare birds, which are classified in the UK as Amber under the Birds of Conservation Concern, migrate to the island all the way from Africa and spend the summer months here bringing up their young before flying back. Nightjars are very unusual looking birds with big gaping mouths, big eyes and very short legs which means they can scarcely walk, but they are exceptionally agile fliers.
Their grey-brown, mottled plumage provides ideal camouflage in the daytime when they are at rest within the heath. The first indication that nightjars are present is usually the male’s churring song which has a hypnotic quality.