Recent Sightings Friday 13th December – The Dashing “Pigeon Hawk” - thanks to volunteer Phil for his article and photos

This day provided one of those special wildlife moments that stay in the memory. It all started in Winpenny Hide, an excellent place to spot birds of prey which often seem to prefer to hunt around the longer grasses near the riverbank, when no less than 3 marsh harriers appeared, drifting together over the Brooks not far from the sluice gate.

They eventually separated and I followed one of the harriers when suddenly, in the background, I spotted a much smaller brown raptor flying fast towards the bank being chased by another crow. The size difference between the much larger crow and the bird of prey was very pronounced and I quickly realised this must be a merlin.  

Very soon the chase disturbed a marsh harrier, probably one of the original 3, and the crow peeled off to mob the harrier while the merlin kept going fast and low along the bottom of the bank. Then to my astonishment it disturbed a red kite, which must have been on the ground for some time and I’d completely missed, before dropping out of sight. 

This has been my third time of spotting a merlin this season and prompted me to find out more about this uncommonly seen species, of which I’ve only ever had a handful of sightings. Not only are they difficult to see but they are even more difficult to photograph and I’ve never managed to do this.

Here are two of Mike Langmans superb illustrations of a male and female merlin.

(rspb-images.com)

The merlin is Britain’s smallest bird of prey, breeding typically in moorland country but increasingly in trees, and moving to open country further south in winter. In common with other birds the UK population increases in the winter as birds from Northern Europe and particularly Iceland take advantage of our milder weather. Every winter a small number of these birds take up residence at Pulborough Brooks.

Perhaps the main difficulty for spotting merlins is their habit of flying low to the ground, using their great agility to hunt small birds and occasionally small mammals and insects. If you spot a large group of ducks or waders taking to the air but don’t spot an obvious bird of prey causing the disturbance, it could just mean that there is a fox nearby, but another possibility is that a merlin has flown by fast and low. They will sometimes perch on fenceposts between feeding sorties and its always worth checking these out for their presence, or indeed any other raptors.

Male merlins have blue grey upper parts and orangey coloured breasts. In common with some other raptors they are smaller than females which have brown upper parts and pale breasts with a barred pattern. This size difference gives the advantage of allowing the adults to take a wider range of species when feeding young. The colour scheme and size differential between the sexes are similar to that of the sparrowhawk so this is perhaps the most likely confusion species. This photo, taken outside the Visitor Centre a few years ago, shows a perched sparrowhawk. 

A perched female or juvenile merlin would look similar, both having prominent bands across the tail feathers. However, if you have a chance to see the breast, merlins have a top to bottom streaked pattern whereas sparrowhawks show horizontal barring as can be seen in this photo taken in my garden.

In flight merlins display the typical pointed wing shape of a falcon whereas sparrowhawks have proportionately broader and more rounded wings and are larger by up to 20% in length.

There are a number of sub species of merlin across the world including North America, where the bird appears to have acquired the name pigeon hawk. This is reflected in the taxonomic species name falco columbarius, derived from the word columba which is Latin for pigeon or dove. However, why it has acquired this name is something of a mystery, as merlins are unlikely to take anything much larger than a thrush, leaving pigeons to its much larger cousin falco peregrinus, the peregrine. 

To conclude I would recommend any visitors to the reserve to keep a close eye out for merlins. Not so many people have ever seen these, and yet they are currently very much in residence and seeing one could give a special wildlife moment.

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