Long John Silver(tit)

Longtailed tits are regular visitors to our garden, so I thought i would try to photograph them again for my Blip.
Once again, I noticed there was an odd number, three today, but its something I have noticed with this species, there is always an odd number, I have no idea why
Another anomaly came to light while I was editing the photographs I took today, this one seems to have only one leg!
A wagtail with one leg visits, and a one legged chaffinch, even a chaffinch with a stump, ie it has one foot missing, and it makes me wonder, how many injured or limbless birds there are out there, does anyone else notice any disabled birds in their gardens?