Is it normal for a sparrow's tail to appear transparent through sunshine?

Last Friday lunchtime, it was really sunny and warm. I had decided to go and check on my patch as it would be low tide at the time.
When I arrived at Crabtree Wharf, as is pretty much always the case, there was a small group of sparrows in a bush by the Thames Path. I don't know if it was the fact that the sun was particularly bright, the angle of it, or that the sparrow was odd, but the tail of this sparrow appeared like transparent in the sunshine:





I'll admit these are not the best photos in the world... I unfortunately couldn't get another angle for another photo.

A small group split and went into smaller bushes by some railings, and I got some much more classic photos, like this one peeking out from behind a leaf:



or these 2 cheeky ones:



Don't you think their feet look like E.T.'s?

There are more photos from that day on the Fulham Sparrows flickr album if you fancy.