Haliaeetus albicilla

White-tailed Eagles have been described as a flying barn door with broad parallel-edged wings, and short tail making this the largest and most imposing British bird of prey. Now a focus of eco-tourism and a familiar star of wildlife photographs, White-tailed Eagle has a sad history in this country.

Also known as Sea Eagle, the local name of Erne was used in northern and western Britain where historical populations had retreated to. It became a species of wild, coastal areas but even here it was wrongfully accused of taking lambs and persecution was heavily supported. By 1916 just one female (an albino) was present on Skye and even she was eventually killed.

In 1975 began one of the most successful reintroduction programmes, albeit one that took many years to secure White-tailed Eagles once more as a part of our natural fauna. Norwegian chicks were reared in holding pens on the Isle of Rhum in the Inner Hebrides, before being released with supplementary feeding provided. It was another 10 years before the first chick was raised, as these long-lived birds reached breeding age and slowly began to learn to rear chicks to fledging. Subsequent additional releases have supplemented the population and numbers are now, slowly, rising.

Archaeological discoveries, and observations of eagles in Europe as the population rises there as well, show that far from being ‘Sea Eagles’ these are birds equally at home in lowland wetlands and marshes. Wandering young birds, both from the British population but also from Scandinavia and the Netherlands, turn up along the East coast each winter and there is a hope that some of these birds may settle.

VITAL STATISTICS

Size: Average 80cm, wingspan 220cm. Weight averages 4.3kg in males, 5.5kg in females.

Status. Re-introduced, resident breeder. Passage visitor.

Population size. 400 pairs.

Conservation status: RED (due to previous historical decline and extirpation, and current low number and restricted distribution).

Lifespan: Average lifespan is estimated at 12 years. Adults have a 70% year-to-year survival. First year survival is low, and the oldest known wild bird was 33 years old (ringing recovery).

Nesting: White-tailed Eagles nest in large stick nests, often in the fork of a large tree, where available, although they will nest on cliffs and crags. Nests are enormous, sometimes measuring several metres across and up to two metres deep. Nests are usually repaired and added to each year.

Number of eggs: 2

Incubation: 38 days

Fledging time: 70-75 days

Habitat and Distribution: Currently this is a species of well-known localities. Certain islands such as Mull and Skye offer excellent chances of encountering this species. Any of the Scottish Atlantic islands can be visited by White-tailed Eagles, and breeding occurs on a number of them. Successful breeding occurred on Hoy, Orkney for the first time in 2018 and there are a number of additional reintroduction options being considered, including some on the lowlands. This is still very much a bird of coastal sites but wintering birds are as likely to be encountered inland on marshes or other, open, habitats.    

Movements: British White-tailed Eagles are relatively sedentary although as with all large, long-lived birds of prey, young birds will explore, travelling sometimes significant distances from their natal site and even leaving the UK before, usually returning to breed not far from their place of birth. As the population is currently so low, there are so many potential breeding territories available.

Feeding: As with many birds of prey, White-tailed Eagles are adaptable and take opportunities as they arise, but fish is an important food item, alongside seabirds. Indeed, in the early days of the Rhum reintroduction young, inexperienced eagles were targeting the numerous Fulmars around the coast, before they learned of the Fulmar’s ability to vomit copious amounts of very sticky fish oil, which led to several youngsters becoming significantly oiled and dying. Other birds are a favourite food item and the range of species taken is large, with birds up to the size of a Grey Heron being taken, although there are records of even Mute Swans being caught and killed.

Mammals may feature in the diet, but these are usually secondary and are invariably either Rabbits and Hares, or carrion. Carrion can be an important part of the diet, especially in winter.

Milvus milvus

The sight of a Red Kite, or two, or three, gently soaring over our countryside is now, once more, a familiar thing. The reintroduction of this species to Britain must rate as one of the conservation success stories of the modern era.

Once a common bird over much of the country, even haunting the litter-ridden and filthy streets, Red Kites were seen as disease-carrying vermin and bounties were paid for their carcasses. The population retreated, finding a final refuge in the valleys of central Wales. A handful of breeding pairs hung on. In 1989, six Swedish birds were released at a site in Scotland and a further four birds were released in the Chilterns.

Red Kites are extremely long-winged and long-tailed and very large, with slightly larger bodies and very much longer wings than a Buzzard. They are predominantly rufous red, with dark wing tips and pale outer wings. The head is pale, with older birds developing almost white heads, and the long, red tail is deeply forked and used as a stabiliser in flight, twisting back and forth – a characteristic clue to the Red Kite’s identity.

Red Kites are found across much of northern Europe and into Iberia in the south west and Russia in the east. Only populations from the western part of the range are resident, those from further east are migratory and one of the challenges for the reintroduction programme was to source birds from a non-migratory population to ensure a similar lifestyle to the previous British kites. Most of the Chilterns birds were sourced from the sedentary and common Spanish population for this reason, although birds for the later, more northerly reintroductions have often been sourced from the thriving Swedish population.   

VITAL STATISTICS

Size: Average 63cm, wingspan 185cm. Females (1.2kg) somewhat larger than males (1kg).

Status: Resident and reintroduced/introduced breeding bird. Passage visitor.

Population size: 2,000 pairs.

Conservation status: GREEN (least concern). Rare breeding bird, having suffered drastic long-term decline, but now common after multiple successful introductions.

Lifespan: Average in the wild of 4 years. Adults have an 61% year-to-year survival. About half of all juveniles will survive their first year. The oldest known wild bird was almost 24 years old (ringing recovery).

Nesting: Nests are usually built high up in a tree, in a fork. Red Kites build their own nest but on occasion will take over an old Buzzard nest. Twigs and sticks continue to be added to the nest during the breeding season, and nests are often reused in subsequent years with some well-used nests becoming very large. The nest cup is lined with grass and often wool, but Red Kites are known for decorating their nests with man-made objects. Plastic bags and brightly coloured plastic items are gathered, and items of clothing (especially underwear) have been known to be acquired for the nest. Even Shakespeare warned: “…when the kite builds, look to lesser linen…”!

Number of eggs: 2

Incubation: 31-32 days

Fledging time: 50-60 days

Distribution and Habitat: Now found across much of the country, the distribution map still shows obvious concentrations around reintroduction areas, such as the Chilterns, Northamptonshire, North Yorkshire, southern Scotland, the Black Isle and, more recently, eastern Ireland. The traditional and last remaining original population of Red Kites, in central Wales, has now spread into much of Wales, and into Shropshire and Herefordshire. In winter, birds wander further and they are now a familiar sight along many of our roads. Kites are fairly catholic in their habitat requirements, although they prefer mixed, open countryside with the main requirement being broad-leaved wooded areas.

Movements: Once adult, Red Kites in the UK are fairly sedentary, but as youngsters in their first two years before breeding kites will often wander large distances and can turn up anywhere. Being sedentary is unusual in a species that across its range is migratory, and northern continental birds are regular in the east of the UK in winter.   

Feeding: Red Kites are renowned as scavengers and are frequently seen along roads, where they target roadkill. Other, larger, animals will attract kites but they will also take live prey. Small mammals are an important part of the diet, but a range of other prey, such as live birds (especially ground-nesting species chicks), reptiles and amphibians is taken. Earthworms feature highly in the diet in spring. In areas of high kite density, garden feeding has become prevalent, with people putting out chicken and other meat for them. Familiarity with humans providing food has led to occasional records of Red Kites stealing food, such as sandwiches, from people in a similar manner to gulls.

Circus pygargus

Montagu’s Harrier is by far our rarest breeding harrier and has partially recovered from near extinction in the 1970s. They are long distance migrants and recently most have nested in arable crops, making them vulnerable to early harvesting or crop management. They rely very heavily on nest protection in this habitat.

They are much smaller birds than Hen Harriers, but have similar length wings, making them even more buoyant and agile. Males are more heavily marked than Hen Harriers, with a dark band on the upper wing, and a series of dark and rufous bands on the underwings. Although grey above, they are marked below, giving them a very different impression. Females can initially seem very similar to Hen Harrier, although the long, narrow wings should help. There are only four visible ‘fingers’ at the wing tips and young birds are a rich rufous colour, likely only to be mistaken for young Pallid Harriers – a rare visitor to the UK.

They are named after George Montagu (1753-1815), an English army officer and naturalist best known for his pioneering Ornithological Dictionary and discovering that the bird now known as Montagu’s Harrier bred in the UK.

VITAL STATISTICS

Size: Average 45cm, wingspan 112cm. Females (380g) larger than males (270g).

Status. Migrant breeding bird. Passage visitor.

Population size. 15 breeding pairs.

Conservation status: AMBER (due to recent population and range decline)

Lifespan: Average lifespan is 6 years, with an adult survival rate of 72% year on year. Juvenile survival is not known. They begin breeding at age of 3 and the oldest known wild bird, was almost 8 years old (ringing recovery).

Nesting: Unlike Hen Harrier, although Montagu’s Harriers will nest on heathland or marshland, most nest in the UK in arable fields, where they do stand the risk of failing due to agricultural activities such as crop spraying.

Number of eggs: 4-5

Incubation: 28-29 days

Fledging time: 35-40 days

Habitat and Distribution: Montagu’s Harrier has always been a scarce if widespread breeding bird in the UK, although numbers crashed. By 1075 there was only one nest, but numbers have slowly recovered a little since then. It is now found in two areas, on the east coast around The Wash and north into Lincolnshire and south Yorkshire; and a second core area in central southern England. Birds can be found hunting over a range of open areas with low vegetation but most UK birds nest in farmland crops.

Movements: Unlike their cousins, Montagu’s Harriers are long-distance migrants and spend the winter in Africa south of the Sahara. The species is widely distributed across Europe and Asia, wintering in Africa and India, but is seldom common. 

Feeding: Montagu’s Harriers hunt in a similar way to other harriers, slowly working back and forth across an area at low altitude watching and listening for prey, which may consist of small mammals, birds, and other similar-sized animals. Due to the long and large wings, Montagu’s Harriers are more agile than other harriers and are able to tackle more agile prey.