Raptor ID Challenge - Is it a true Western Marsh Harrier

If you look at this blog you realise I placed them as Western Marsh Harrier. However many of you all who have follow my discussion in many other places also aware that I did mention that this was a hybrid but more western than eastern. 

So what is it? How does this become a hybrid and how do we tell them apart. I will leave this part open for a while for reader to have their own answer before I provide the result of discussion. See photo below.

ANSWER AND DISCUSSION

To begin with in the first glance there is nothing to suggest that this was Eastern Marsh Harrier. However, we can’t come into agreement that it was Western either. Let’s begin with the head patter. While the dark marking for the side of head and necked join to the eye – typically suggest the id as Western Marsh Harrier – the patched were too large and non typical design of the Western. However not joining and no evidence of crescent also mean that this individual is not Eastern Marsh Harrier.

 

This does not mean that we immediately have a hybrid. It is also known that the Western Marsh Harrier have dark morph variation. Individual observed inf light show no evidence of barring which is also more typical of Western rather than Eastern Marsh Harrier.

 

While all this seem to work in and out between Western and Eastern Marsh Harrier, other feature were look into. At such age the rump should show all dark for Western and white in Eastern and intermediaries’ plumage silvery grey for Western. This plumage here however show neither. A part from being very narrow it also pale brownish in colour. The marking as in the picture are not common to either both. The dark chocolate in colour below are also not typical of for Eastern Marsh Harrier population sighted in this country. 

 

On the upperwing there is also no evidence of pale creamy colour of the upper wing covert and leading edge a marking should be noted at this age making the idea this would have been a dark morph variation of hybrid. 

 

Although the picture is rather decent for identification, it is to many of us were not able to reach accepted conclusion to lean this as hybrid or just placed in Western Marsh Harrier. As for this there is no proper classification can be done when they are hybrid. There is many feature of this bird where already leaning towards Western but it will not be appropriate for the team to immediately conclude this as Western without acknowledge the possibility of this being hybrid. As for this this blog at previously accepted it on species level of Western Marsh Harrier with the understanding this is a hybrid. 

 

(This blog have yet to placed anything of hybrid previously due to needs of further research and technical analysis. Current year have shown the increase in number of record of harrier identified as hybrid in the country and we noted that this population now deserve to be recognize as hybrid population and not concluded as species level as done previosuly)

 

As of today we have noted this individual as Western Marsh Harrier X Eastern Marsh Harrier.