A Black Kite at Duncombe Park and thoughts on its provenance

  

 

A rare Black Kite was at Duncombe park for a week or so, often associating with the display birds at the national bird of prey centre. While most birders who have seen it seem happy enough to tick it as a wild bird, its location has led to some doubts being expressed over its provenance. Some have even gone as far as to state categorically  that it’s an escapee.

 

So before I describe my visit to see it lets examine its provenance. As anyone who has read my blogs before will know , I’m a scientist with a doctorate in Physics and this drives me to analyse problems such as the provenance of this bird with as much logic as possible. In this regard I feel it is very important to state clearly what is a fact and what is based on a balance of probabilities.

 

So let’s start with the facts. 

 

To start with it must be stated that historically there have been,  and probably still are, both genuinely wild and  escaped captive Black Kites present in the UK. The relative population of each at any one time is uncertain.

 

So how can you say that a bird is genuinely wild? My understanding is that there are only two attributes that can prove a Black Kite is wild with complete certainty. Firstly, it was ringed in the nest in its normal range as a chick. Secondly, isotopic analysis of a sample of the bird has tied down where it has come from. I won’t go into how isotopic analysis works in detail here but it relies on the fact that different regional geologies have different isotopic mixes which the bird will have ingested via the food chain if present there. 

 

Conversely, how can you tell with certainly that the bird has escaped from captivity? If it carries any hardware from its captivity, owners rings, jesses etc. or if it shows signs of previous wing clipping it is certainly guilty of being an escape.

 

Unfortunately, most birds do not satisfy either of the above criteria so we are left with a more subjective balance of probabilities analysis of provenance. It is hence obvious that if you want to be puritanical and be 100% sure that you have seen a wild Black Kite in the UK you won’t be ticking one anytime soon! Most birders hence take a balanced view of various criteria to decide themselves if they are happy to tick the bird. As an example if you on the east coast looking out to sea during the spring migration and you see a Black Kite fly in off the sea the balance of probabilities would say that it is probably wild. With rarer birds that are subject to analysis by the various rare bird committees you can wait and see if it gets a majority vote of blessing from the experts but in my experience many of these decisions lack true scientific vigour.

 

Now specifically with regard to the Duncombe park bird, it passes the first test for a wild bird of having no physical indications of previously being kept in captivity. It has been condemned by some by its physical location and association with captive birds. Although the bird of prey centre are absolutely adamant that they have not lost a bird, and I have spoken to them personally to confirm this, some have gone as far as to imply that they are covering up an embarrassing escape. I personally, not being a subscriber to conspiracy  theories, find this extremely hard to believe. There is also other strong evidence that condemns this conspiracy theory to the bin it deserves to be in, the display birds are Yellow-Billed Kites, the Afrotropic counterpart of the Black Kite. The free flying bird, however,  is definitely a Black Kite. 

 

It has also been condemned by its association with the captive birds during free flying displays. This, in my mind at least, is illogical as this type of association is exactly how birds behave in the wild. This is evidenced by the local wild Red Kites which regularly appear during the flying displays. To my ear, the call of the Black Kite was identical to that of its Yellow Billed counterparts which called continuously during the display. So it really should be no surprise to anyone that the captive bird calls are attractive to it.

 

To further add weight to the wild argument it has now moved on.

 

Based on the above I see no reason why this bird cannot be  judged as wild as most others that are seen in the UK and in the absence of any new evidence to the contrary I’m happy to tick it.

 

The national bird of prey centre is located at the pleasant Duncombe park just outside of the town of Hemsley. A three hour mainly motorway drive had me parking up at the centre at 09:30. I went into the reception and parted with the princely sum of £1 for parking and chatted to the staff about the best place to see the bird. The staff were, again, absolutely adamant that it was not their bird! I was told the best place to watch from was the high ground in front of the stately home so I made my way there in what can only be described as mixed weather which set the tone for the whole day, squally hail and rain showers intermixed with sunny intervals of relative calm. I set my scope up and started to scan the surrounding countryside and within 5 minutes I saw the unmistakeable silhouette of the Black Kite approaching me. 

 

In stark contrast to its rarity in the UK, it is a very common bird globally. It is widely distributed through the temperate and tropical parts of Eurasia  and parts of Australasia and Oceania  with an estimated population of 6 million birds. Black Kites can be distinguished from Red Kites  by their slightly smaller size, less forked tail, and generally dark plumage. They lack the attractive rufous tones of their red cousins and, if truth by told, are an altogether a duller bird.

 

The Black Kite flew over me allowing me to take a few pictures before it drifted off on the wind behind the stately home. This set the tone for the whole 7 hours I was on site with some 5 or 6 good views of the bird flying overhead before drifting off. It was often associating with a group of wild Red Kites providing a good comparison of their clear differences. The Black Kite would occasionally call in the whistle like manner of many birds of prey.

 

There were three displays during the day at the bird of prey centre, the last one being notable for the 5 or so Yellow Billed Kites being flown. As per above, these are the African counterparts of the Black Kite and are treated by some as a separate species. To my ear the calls of the Black and Yellow Billed kites were identical and this certainly got the attention of both the free flying Red and Black Kites who returned their call.

 

After this last display at 16:30 I made my way back to the car for my long drive home extremely contended with the views of the Black Kite

 

 

 

  Footnote – my blogs are posted with sometimes rather imaginative spelling and grammar due to my extreme dyslexia!