Robins

[Stargazer]

How can one distinguish a male from a female?

[Tilly2]

https://www.birdspot.co.uk/bird-brain/how-can-you-tell-male-and-female-robins-apart

[choux]

Apparently, one cannot be c_ocksure then?

[bhg481]

ladybirder explained the difference in this thread:

https://www.theanswerbank.co.uk/Animals-and-Nature/Twitching-and-Birdwatching/Question1781151-1.html

and I put a couple of pictures on.

[Chipchopper]

I would think another robin could tell the difference easy enough :-)
Funnily enough, I was thinking the same thing when I saw two jays in the garden earlier today, then I noticed one of them had slightly larger blue wing patches than the other, and I reckon that was the male.

[ToraToraTora]

Did You Know, robins are the jack Russells of the small song bird world and regularly attack other birds with a lot of aggression.

[ladybirder]

Yes, I knew that having had many JRs in my life. Got a terrier now but he's not bi-coloured so he's not a JR, just a terrier I suppose.