Pallids Performing Perfectly…
The Pallid Harrier (Circus macrourus) up until now has been regarded as quite an exotic bird on the Iberian peninsular. Any sightings are fairly localised and take place during the migration seasons of spring and autumn. The increased number of sightings continues as this species expands it's breeding range into central Europe and Scandinavia. Pallids successfully bred in Finland this year.
There were two Pallids at La Janda the other day, one sat quite happilly preening as my friend Andy Paterson and I watched from the main track. The other Pallid was hidden from view by taller folliage on the edge of the rice-field. It wasn't until both birds took off that we realised that there were in fact two Pallids.
The head pattern is diagnostic showing this light ring or collar around the neck. We saw the yellow iris colour which told us that this one was a juvenile male. I didn't get close views or photos to tell the sex of the other bird.
The first thing that an observer may see is the general colour of the bird. It's a rich ochre over most of the body and the feathers on the trailing edge of the wing seem very even, typical of fresh birds. You may know this information from field guides and it is typical of juvenile birds, particularly with newly fledged harriers.
The head pattern is diagnostic showing this white ring or collar around the neck although head pattern can be quite variable.
You can also see the boldly barred primaries with pale bases on the underwing, another feature with Pallids identification.
One bird began to fly and hunt and the other flew off left and I did manage to some flight shots. During this short period we managed to see some of the other identification detail.
Males are smaller than females and move around in flight with a light dancing bounce, rather like a Montagu's Harrier. The females are heavier and more robust and just don't have that light agile performance and are more businesslike as with Hen Harriers.
The adult male Pallid we saw a few weeks ago had this flight pattern and now that more Hen Harriers are coming through the area, there have been some false alarms with adult male Hen Harriers that were thought to have been the lone adult male Pallid or even a second adult male Pallid turning up in our area.
Even at a distance you'd have to check out the wing tips or hand on both upper and under, then it would be clear even from afar. They are pointed black in Pallid on a thinner wing whereas adutl male Hen Harrier has broader wing, heavier in flight and the black hand is larger and almost squared off. Both are distinct and pretty straightforward unlike juveniles.
Now that I have seen more Pallid flight, there is a difference even at a distance. Females and especially juveniles at a distance can be extremely difficult, even to experienced birders. Just to complicate things there is the suggestion that hybridisation takes place between Hen Harrier and Pallid Harrier and that the offspring can show features of both species.
Dick Forsman posted a forum link about this very phenomenon here
and you can see one very interesting photo here
You might pick up some details from these rather distant shots that I managed to take.
See the black wingtip area and size of the 'hand' on the juvenile Pallid which is more open and less black on that of juvenile Montagu's (Circus pygargus)
You can see how loose the primaries are in this photo comparison
Like the Montagu's the Pallid has four fingers with the Hen Harrier having five.
Juveniles have an unstreaked body and you can perhaps make out the irregular underwing barring to the primaries which is typical with Pallids (See the other photos of the underwing in of this hunting sequence above)
Some wing moult is already underway and normally there will be a first winter body moult too. Pallids moult quicker than Montagu's as well
The morning sun lights up this hunting Pallid giving a slightly lighter look in the underwing.
A view not often seen and you can see the obvious light collar
Narrower wing structure easpecially at the hand than with Hen Harrier. The collar shows up in stark contrast with juvenile plumage
It looks like the other bird has moulted the central tail feathers. You can see the pale edges to the primaries in this photo.