Mini logo

Hen Harriers.

Posted in:

Frequently Asked Questions

What is a Hen Harrier?

Hen Harriers are medium sized birds of prey, with a wingspan of just over a metre, which breed in upland areas in the UK.

Where do Hen Harriers nest?

Hen Harriers usually nest on the ground, in a clump of heather or rushes; in the UK this is often in upland areas of moorland. In France they often nest in tall cereal crops. The location of the nest at Muirshiel is not disclosed as this may put the birds at risk of disturbance. The birds choose a different site each year.

Where can I see one?

If you come to Muirshiel Country Park during the breeding season, April to August, you have a reasonable chance of spotting harriers hunting across the moors. The mine track walk is one of the best view points. We may also have LIVE video from the nest in the Visitor Centre during nesting season.

Where do they live?

Hen Harriers breed in upland areas of the UK, in the winter they move down to lower land along the coast or marshland areas where the winter hunting is better. Hen Harriers are also found across Europe and Asia.

Are they here all year?

No the Hen Harriers usually leave Muirshiel in the autumn. Harriers in the UK are partial migrants, that is they summer and breed in the high moors then move downhill in the winter to follow their food source.

Where do they go in winter?

They might travel a few dozen miles to a winter location with a good food supply or could fly as far as France or Ireland. But not a lot is known about their migration patterns, recent studies have included satellite tagging harriers to follow them when they leave the nesting areas.

How long do they live for?

The oldest ringed recovered Hen Harrier was 15yrs, 9 months but it is likely that they live for between 5 – 9 years; most juveniles will die in their first winter as they learn to hunt efficiently. Only 2 out of 5 will live to 2 years old, when they reach breeding maturity.

How big are they?

Females are about the same size as a common buzzard, but much lighter in build. The male bird is about one third smaller than the female. Males have a wing span of about 1.1 metre, and females about 1.3m, males weigh about 350g and females about 500g.

What do they eat?

Hen harriers eat small mammals and birds, at Muirshiel their diet includes, short-toed field voles, meadow pipits and skylarks.  More unusual items of prey have included, grouse, lapwing and curlew chicks, small rabbits and stoats.

Why are they protected?

Harriers are protected because in the past they were heavily persecuted, they were killed by humans with a vested interest in game shooting and almost all harriers on mainland Britain were eliminated. Nowadays because they are protected and attitudes have changed this is much less of a problem but the numbers of harriers are still below historical figures and due to habitat loss the population is struggling to increase. Protection of the birds and their moorland habitat is giving them the best chance to recover.

How are they protected?

Hen Harriers are protected under European, UK and Scot’s law. They are listed as schedule 1 in the Wildlife and Countryside Act (1981) and Nature Conservation (Scotland) Act 2004 which gives the highest level of protection in the UK, it is illegal to disturb them at the nest, photograph them or interfere with a nest without a licence. Heavy fines and jail terms can be given to those found guilty of such crimes.

Why are they so rare?

Hen harriers have been historically persecuted by man and modern habitat loss are the main factors. There are about 650 pairs in the UK.

Why are they called Hen Harriers?

Because, when they were much more common in the past they would take chickens and hens from the yards of farms and houses. Their hunting style harries the birds into flight where they are caught. In Holland their name translates as ‘blue chicken thief’.

How many eggs are usual for a nest?

4 to 5 eggs is the normal clutch and these are laid one every 2 days or so.

Do you get them anywhere else?

There are Hen Harriers throughout the greater European continent, into Asia and North Africa. About 1000 pairs breed in France and there are about 80 pairs in Germany, 500 pairs in Spain, 100 pairs in the Netherlands, 1000 pairs in Sweden and 600 pairs in Finland, and 100 in Estonia. Numbers are more difficult to estimate for the more eastern parts of Europe and Asia but the total world population is likely to be about 30 – 40,000.

Why do they Sky-dance?

Hen Harriers probably sky-dance for two reasons: to mark their territory and to attract mates.

Why do they food pass in the air?

Male birds pass food to the females in a mid air food-pass, foot to foot, most likely so that the prey is not lost in the deep vegetation on the moorland and it is safer not to land where there may be predators.

How many Hen Harriers are there?

In the UK there are only about 650 pairs of breeding Hen Harriers; most of these are in the very north of Scotland, the Western Isles and Orkney, only 10 pairs breed in England, similar numbers to Muirshiel.

Why are they different colours?

The female needs to be well camouflaged because while she is sitting on the eggs for a month, she and her chicks are vulnerable on the ground and doesn’t want to attract predators to the nest.  The male is pale grey like an overcast sky, and his white belly flashes in the sun when he sky-dances.

How long are the eggs incubated?

Eggs usually hatch after 31-34 days incubation.

How long are the young in the nest?

The young take about 37 days or so to fledge or leave the nest.

Do the young birds stay with their parents?

For a time after leaving the nest fledglings will follow their parents to watch them hunt and catch food and gradually learn to do this for themselves over several weeks or months.

Does the male help to incubate the eggs?

Only in very exceptional conditions will the male try to incubate the eggs and raise young on his own, but this is not likely to be successful. The female usually does all the incubation and stays at the nest to protect it while the male does most of the hunting.

How many pairs are there?

There are about 650 pairs of breeding Hen Harriers in the UK, with up to 10 pairs at Muirshiel.

Do they mate for life?  

It is not known for sure, but it appears at Muirshiel that males compete for females each year by displaying and giving them food, so it is probably up to her if she wants him back! Females will choose a male that is a good provider of food and has a good territory. In areas such as Orkney with a higher number of females the male will mate with several females (polygyny) and she may have to compete for his attention.

How safe are ground-nesting birds?

It is a dangerous place to nest on the ground, foxes, mink, crows and even people and dogs can get to the nest easily, so it is well hidden in the heather and the female keeps the eggs covered from prying eyes in the sky. Even so probably about half of all nests will fail due to predators, bad weather or disturbance.

Leave a Reply

Make a booking