Izzy's UEA Ecology blog

The grey squirrel ( Sciurus carolinensis ) is a cute and charismatic species, commonly seen in rural areas and urban parks, but this species causes problems for native wildlife. Since being introduced from North America in the 19th century, the grey squirrel has successfully spread across almost the entirety of Britain, with some exceptions including northern Scotland, Anglesey and the Isle of Wight.  A startled baby grey squirrel in a deciduous woodland, Hampshire Larger than the red squirrel, grey squirrels weigh around 400-600g, are 24-29cm long, and have an impressive, fluffy tail around 20cm long. Other than the obvious difference in colour, the two species can also be distinguished by the grey's lack of ear tufts. Deciduous woodland is the primary habitat of grey squirrels, but they are also common in parks and gardens, often seen visiting bird feeders. Wild food sources include acorns, plant shoots, fungi, hazelnuts and seeds from pine cones, which they extract by nibbling a...

 The turn of the seasons is marked by the arrival of the summer migrants. One of these is the cuckoo, Cuculus canorus , which travels north from Africa to breed in Europe.  Cuckoos have grey upper parts and chest, and barred underparts. ( James West , creative commons license) This species is well known for its brood parasitism - laying its eggs in the nests of other birds. In Britain, the most commonly parasitized species varies depending on the habitat type. In moorland and healthland meadow pipits are the primary targets, reed warblers in marshland, and dunnocks in woodland and farmland. In the absence of these species cuckoos will also parasitize the nests of robins and pied wagtails. The slight size difference between male and female cuckoos is likely to have come about due to selection pressure on females to be smaller, therefore laying smaller eggs to match the small host eggs. This is different to many bird species where size dimorphism evolves due to sexual selection ...

The blackbird ( Turdus merula ) is a much loved species, ubiquitous across the UK with the exception of some areas in northern Scotland. Males are particularly identifiable - living up to their name, they are entirely black with a striking yellow-orange beak and eye rings. Females are less conspicuous as they are all brown with some speckling on the breast. Both sexes weigh 80-100g. Originally a woodland bird, the blackbird has been particularly successful in gardens - their breeding season can start 2 weeks earlier in gardens than in woodland, and breeding success is often higher. This may be because of food provided in gardens, or lower nest predation rates in urban areas compared to rural.  A male blackbird taking food to his chicks in the nest. Across their woodland, grassland, and garden habitats blackbirds eat a variety of foods, including insects, fruit and berries. Earthworms constitute a large part of this species' diet, and they find them by listening for their movement b...

The wood mouse ( Apodemus sylvaticus ) is the most common rodent in the UK, it's generalist feeding habits allowing it to be ubiquitous across most of the country. It's range also spans most of Europe and northern Africa. Despite their name, wood mice are not just a woodland species - they are also found in grassland, farmland, heathland and gardens. A. sylvaticus is a nocturnal species, foraging predominantly under the cover of darkness. They are good climbers and have large back feet to assist leaping.  In winter, wood mice nest communally, then in spring females will leave for their home range and nest singly, with males roaming over an area occupied by a few females. Nests are made of leaves, moss and grass, either in underground chambers, in buildings or in nest boxes. Burrows are generally used by successive generations who may enlarge and modify them. In each burrow there are multiple sections for nest chambers and food stores.  The lifespan of these small mammals ...

One springtime event I await with eager anticipation each year is the emergence of the bluebells. From late March a few nodding heads emerge sporadically across the woodland floor, and by late April they are out in full splendour, their blue hue carpeting the ground.  A display of bluebells in a broadleaved woodland, Hampshire  Compared to many wildflower species, the English or common bluebell ( Hyacinthoides non-scripta ) blooms early. This is an adaptation to its woodland habitat, to allow photosynthesis and accumulation of resources before the forest canopy becomes too dense and reduces light intensity at ground level. Bluebells can be considered ancient woodland indicators due to their slow rate of spread - populations spread up to 6cm per year .  In wetter areas, such as the west coast of the British Isles,  H. non-scripta can also grow in more open habitats, where summer cover is provided by bracken ( Pteridium aquilinum ). Bluebells have been shown to flower ...