Common terns are they aggressive by nature....?

[bassist]

Was at preston docks the other day,when one of the terns spotted a crow.It did an about turn in the air and was off after it, dive bombing the crow until it had forced it to land on the ground.They are not nesting,which led me to think are they aggressive birds by nature.........?cool to watch though...!Peace...!

[astafjevs]

Based on the Arctic Terns featured on Springwatch this evening, I'd say yes! They seem to go to great lengths to defend their territory, and a crow would be an obvious nest predator. If they're not nesting, maybe its an instinct kicking in?

Incidentally, under your excellent recent tern picture I've posted a question regarding the differences between tern species. (just in case noone's seen it!)

[alanjns]

Hi astafjevs,

Terns differ in size, colouration and flight pattern. The easiest way of telling them apart may be from their bills. Sandwich, Black and Roseate Terns have black bills, Little Terns have an orange bill with a black tip and Common and Artic Terns have a red bill, but the Common Tern has a red tip to it.

In Bassists pics you can just about make out the black tip - especially in the 2nd pic.

This is all from my RSPB guide by the way, I haven't suddenly 'terned' into Bill Oddie

Cheers,

Alan

[clydebirder]

In mid - late Summer the wing pattern is the best way to ID Arctic from Common Terns. Common Terns have a grey wedge on the upper primaries which is obvious from a fair distance away, the Arctic is much cleaner winged with no obvious grey on upper primaries. From underneath the Arctic Tern only has a small dark neat border to the trailing edge of the primaries whereas the Common has larger more diffuse dark markings on the underside of the primaries. Some Arctic Terns can have a diffuse dark tip to the bill which can cause confusion, tail streamers are longer on Arctic but in late summer can be broken off

cheers, John

[astafjevs]

thanks guys, appreciate it.

will keep looking, if I ever manage to see one I will then start work on trying to work out which sort it is! There don't seem to be too many decent sites for terns in my area, I did visit the Camel estuary in Cornwall earlier in the year but it was probably too early for them.

Hopefully, my luck will 'tern' soon!!