I WAS very fortunate to be invited to the York Bird of Prey Centre in Huby for the launch of the Tourism Association of North Yorkshire (TANY) 2018 visitor guide. TANY is a small, independent organisation that relies on volunteers, and does sterling work in promoting our region, especially Ryedale, Hambleton and the North York Moors, to support local businesses in attracting valuable tourists to our beautiful part of the world.

I’d contributed a tribute to my dad, which is why I was asked along. What I didn’t expect was to be able to sit among the birds as they flew freely around us, tempted by morsels of meat placed in certain spots. We were invited to handle the birds ourselves, and I got up close and personal with a stunning barn owl, a southern crested caracara (a type of falcon), a sweet tawny owl and a majestic golden eagle. We were taught about the valuable education and conservation work the centre does, and learned that the birds get hours of free flying time outside of their aviaries every day (I must admit, I was wondering about that).

It’s a rare privilege to be able to get so close, and really made me appreciate just how amazing these birds of prey are. My parents were both (and my mum still is) keen bird watchers, and had installed several nesting boxes and feeders in their garden, keeping binoculars by the window so they could observe the daily antics of their feathered friends. They were both very knowledgeable and could instantly identify most birds that visited.

I can’t remember them ever mentioning a white blackbird though. In fact, until this week when I read my dad’s column from March 25, 1978, I had no idea they even existed. But apparently so, as a reader had written to ask Dad if white blackbirds were rare. Dad remembered having seen one in the grounds of the Bowes Museum in Barnard Castle. I assumed this would have been some kind of albino, but not necessarily, as, with help from the RSPB, I’ve discovered that some birds are simply lacking in the pigment that colours the feathers.

Further research revealed that the colouring of birds is in fact quite complicated, and just because a bird appears to be iridescent blue or green in colour does not mean they have blue or green feathers. In fact, the colour is created by the light being reflected off the complex structure of the feathers, making them appear blue or green. These are known as ‘structural’ colours. The true colour of many iridescent feathers is actually brown.

So, for example, if you see a kingfisher in low light, it will often appear dark in colour. Blacks, browns, chestnut-reds and yellows are created by melanin, a pigment which does colour the actual feather and also influences the intensity of the hue. Other colours are created by the process of the underlying pigment combining with a structural colour. For example, some parrots have an underlying pigment of yellow that interacts with a blue structural colour, which then makes the parrot appear green.

Anyway, back to our unusual white blackbird. Occasionally, the normal process that produces a bird’s colour breaks down, which can result in no pigmentation, or patchy pigmentation. A brief search on the internet throws up pictures of all sorts of wonderful patterns on the blackbird’s feathers, from pure white, to black with a white head, collar, breast or tail, white with black spots, black with white spots, or even black with white ‘go-faster’ stripes down the side.

Often the captions on these pictures mistakenly describes them as ‘albino’ or ‘part-albino’. As far as I am aware, it is impossible for anything to be ‘part-albino’. All vertebrates can be affected by albinism, which is a genetic mutation leading to reduced or complete absence of the pigment melanin which is responsible for colouring skin, hair, eyes, fur and feathers. The difference between a white blackbird and an albino blackbird is that albinos have pink or red eyes rather than black, because the lack of pigmentation means the blood can be seen. They will also have pale skin, legs, feet and beaks.

I saw recently wildlife artist and fellow columnist Robert Fuller’s wonderful video of the white stoat in his garden. I’d love to find out if readers have spotted any other unexpectedly white creatures in their gardens, or out and about.

Sadly, I have yet to clap my eyes on the elusive white blackbird.