On Red Kites, Marsh Harriers, and the magnificent Spanish Imperial Eagle
British Trust for Ornithology ID Training
Over the last six months we haven’t been able get out nearly as much as we would have hoped. In compensation perhaps, we attended a series of excellent ZOOM courses run by the British Trust for Ornithology training team, Nick Moran, Emily Cuff and others. We’ve learned an enormous amount on the identification of such tricky customers as young gulls, waders, and warblers – and great fun it was too.
At the end of this month (January 2022) we’ll be joining a course on British raptors, and in prep we’ve been brushing up on some of the finer points of identification.
Two interesting contenders on the course are Red Kites and Marsh Harriers. Really there shouldn’t be any confusion here, except that both species can have a rich brown coloured plumage, buoyant flight, and the Red Kite will hunt in the type of terrain favoured by Marsh Harriers.
… but first, Red and Black Kites
But for those of you who have the opportunity to bird watch in Southern Europe, the Black Kite will be the bird most likely to be confused with its Red counterpart, and indeed there are times when they can be very difficult to tell apart.
In poor light conditions it can be difficult to spot the difference, but the are a number of pointers that will help, including the fact that the Red Kite is a resident bird, and the Black a summer migrant, and so at least they only offer a tantalising challenge for half the year – see: https://woodcockwood.com/red-kites-and-black-kites.
There are between 20 and 30 sightings of the Black Kite in the south of England each year, and it is tipped to be one of the birds most likely to increase in numbers and even breed here, as our climate warms. And so, even if you don’t often travel to Southern Europe, it may be worth keeping a note of the distinction as their number will almost certainly be increasing in the UK over the next decade.
Red Kites
Red Kites have a relatively small range, being confined to parts of Europe and North Africa. In the UK they are one of our success stories. While in most parts of its range it has the dubious status of “near threatened” in the UK it was moved to the Green List in 20151.
In spite of this status, to us, they are still the most frequently seen raptor on our route south into Spain and Portugal. Everything about them spells speed and agility. They are beautiful birds to watch.
Marsh Harriers
The Marsh Harrier has a wide distribution across Europe and Asia. Some are sedentary, others migrate south to Africa. In the UK we have watched Marsh Harriers in Norfolk and Dungeness.
In Spain they are widespread, and we have seen them in the north, on the open plains of Tierra de Campos, and in the Extremadura.
The Marsh Harrier is the largest of the European Harriers. It hunts by sight and sound, quartering its territory 4 to 5 metres above the ground, dipping and rising with the contours, keeping close to hedge rows and ditches, in constant patrol. It will take small mammals, birds, ducks, and reptiles. We once inadvertently flushed a pair feeding from a perfectly skinned hare.
Travelling between Toledo and Alburquerque, we parked up for the night outside of Parque Natural de Cornalvo, on the side of a farm track and overlooking wheat stubble fields. What a privilege to have such a view as the evening drew in, watching a pair of Marsh Harriers quartering the immense field. They were there as the sun went down and again when it rose in the morning.
The adult males are more variable in their plumage than the Hen and Montagu’s Harrier, and overall tend to be darker. All have characteristic black wingtips, some have pale grey wings and chestnut streaked bodies, and others chestnut predominates over body and wings. But even in the dark males, the pale flight feathers tipped with black remain.
The females are larger than the male, with an overall appearance of dark brown plumage. The crown of the head is white, and some have a distinctive pale leading edge to the wing. This becomes more distinctive with increasing age – see below.
… and so where the confusion between Red Kites and Marsh Harrier?
There shouldn’t be any really when all is considered. The low, slow quartering flights of the Marsh Harrier compared to the obvious speed and agility of the Red Kite as it patrols its patch in search of live food or carrion can’t be mistaken. The jizz is unmistakable, but the following photos illustrate how, on occasions, mistakes can be made.
The Spanish Imperial Eagle
The first time we saw a Spanish Imperial Eagle was in 2019 when we spent a week with Martin Kelsey and a couple of friends identifying and watching the eagles of central Spain. It was a rather unedifying view of such a noble bird, early in the morning and still cold. The eagle was hunched by a pile of gravel at the edge of a field over looking a busy main road. The eagle didn’t move. It was waiting for the sun to rise and warm it sufficiently to enable it to take to the air.
The next time was in the following year. Chris and I had spent the day walking a trail in the Parque National de Cabañeros. We had seen little all day other than numerous Griffon Vultures. The sun was setting, and we working our way down a steep track towards the car park. The track looked down an immense valley. In the distance we saw a speck of a raptor circling …. just another Griffon. As the bird turn towards us, catching the setting sun, we saw a flash of white across it’s head a shoulders. Even at that distance it was clearly a Spanish Imperial Eagle. We were spellbound. It was a wonderful sight.
Since then we have seen them on several occasions, including once, close to Trejillo, when we were able to photograph it. We were in a location we know that is good for raptors, bordering Parque Nacional Monfragüe – an area of Dehesa – cork oak and cattle, and vast rolling fields of grain. Spanish Imperial Eagles are tree nesting birds favouring open and flat terrain. The Dehesa of Extremadura is ideal habitat.
We had pulled over in an entrance to a ranch and were scanning the skies, and there in the distance was the unmistakable shape of an eagle. As we watched, the white head and shoulders came into view as it slowly circled not too much above the tree line. We kept this bird in view for ages. Sadly it didn’t move closer. We saw what was presumably the same bird the following day in a location nearby.
The Spanish Imperial Eagle is a separate race of the European / Asian Imperial Eagle. The Spanish Imperial Eagle is another one of the large raptors that reached near-extinction during the mid 1900s, and has been brought back from the brink through a concerted conservation plan.
According to the EU Biodiversity Case Study Hub, the Spanish Imperial Eagle’s population is now stable. The ” … Spanish population is estimated to have increased by 135% from 2001 to 2012 and the species recolonised Portugal in 2003. According to the most recent published data, 358 pairs were counted in Spain in 2012, giving an overall estimate of c.370-380 pairs, and the Portuguese population was estimated at 11-18 pairs in 2013; so the current total population is around 1,100 individuals.” Since the publication of these figures I’m assuming the population has continued its slow growth – https://biodiversity.europa.eu
Is there a possible point of confusion between the Spanish Imperial Eagle and the Marsh Harrier?
One of our regular stopovers on our journey to Portugal is a “secret” spot called Valbuena de Pisuerga. There’s a single lane track turning off the busy main road. The track leads up to the village, but before you reach it there’s a derelict building facing across a small field onto a beautiful wooded hillside – a great spot for coffee and birding: see https://woodcockwood.com/marsh-harrier-identification-features.
A couple of years ago we saw a female Marsh Harrier flying low over the hill. It was some distance away. Initially all we saw was a large dark raptor with white head and shoulders. So ingrained is this feature that our initial reaction was Spanish Imperial Eagle. This is what we wanted it to be.
As it turned we could see long legs and long narrow wings of the harrier – a lovely bird to see, but there’s always a come down when you realise the most exotic has been replaced by something a little less rare and exquisite.
… but it’s what makes birding so wonderfully exciting!
1“Bird Trends 2018 – Trends in Numbers, Breeding Success and Survival for UK Breeding Birds” 2019, Ian Woodward et al, BTO Publications