Wren butts

[smittyone@cox.net]

This Wren was seen yesterday afternoon in western Iowa.  My question is regarding their tail feathers (or lack thereof).  I've noticed this seems pretty common with Dickcissels right now too.  Do these birds completely lose their tail feathers and grow brand new ones every year?  Or is it only immature birds I'm seeing growing their very first tail feathers?   

[blackburnian]

This is a House Wren. 

[Charlie Spencer]

Most birds replace their feathers regularly, but I'm not aware of any songbirds that replace all their tail feathers at once.  Obviously, it makes it more challenging to fly.  I'm -guessing- this bird had a narrow escape from something that was looking for lunch, but got only a mouthful of tail feathers instead,

[The Bird Nuts]

Juveniles do have short tails when they leave the nest.  Here is a photo I took a few days ago of a House Wren that just fledged.

Your bird is a molting adult as its feathers are quite raggedy and it shows no large yellow gape flange.  But I don't know if it molted its tail feathers or if it lost them another way.  Anyway, it should have nice new feathers soon.

Edited August 25, 2020 by The Bird Nuts

[Tony Leukering]

In birds, annual feather replacement is, generally, gradual. That is because flight performance is negatively impacted by molt and slow-and-steady reduces how negatively, at the expense of increasing the amount of time in which performance is reduced. However, there are groups that always/nearly always drop flight feathers, if not all at once, close to it. Waterfowl become flightless due to their strategy, which is aimed at keeping flight performance reduced to a temporal minimum.

Some passerine groups, particularly blackbirds (Icteridae), show a tendency to drop all or most of their tail feathers at once, with Common Grackle being the poster species for that strategy, at least in my experience. Given the generally tight habitats of House Wren and the difficulty of capturing one for dinner, it would not surprise me if individuals were to regularly drop all or most of the tail at once. However, Charlie's suggestion is also probably true in many cases. I have certainly seen quite a few accipiters come out of an attack with only a small fistful of tail feathers.

[Charlie Spencer]

45 minutes ago, The Bird Nuts said:

Juveniles do have short tails when they leave the nest.  Here is a photo I took a few days ago of a House Wren that just fledged.

Your bird is a molting adult as its feathers are quite raggedy and it shows no large yellow gape flange.  But I don't know if it molted its tail feathers or if it lost them another way.  Anyway, it should have nice new feathers soon.

I'm out of 'Likes' again.  Thanks!

[Charlie Spencer]

48 minutes ago, Tony Leukering said:

In birds, annual feather replacement is, generally, gradual. That is because flight performance is negatively impacted by molt and slow-and-steady reduces how negatively, at the expense of increasing the amount of time in which performance is reduced. However, there are groups that always/nearly always drop flight feathers, if not all at once, close to it. Waterfowl become flightless due to their strategy, which is aimed at keeping flight performance reduced to a temporal minimum.

Some passerine groups, particularly blackbirds (Icteridae), show a tendency to drop all or most of their tail feathers at once, with Common Grackle being the poster species for that strategy, at least in my experience. Given the generally tight habitats of House Wren and the difficulty of capturing one for dinner, it would not surprise me if individuals were to regularly drop all or most of the tail at once. However, Charlie's suggestion is also probably true in many cases. I have certainly seen quite a few accipiters come out of an attack with only a small fistful of tail feathers.

Ditto!

[smittyone@cox.net]

Thanks for the info folks.  I learn so much here, not just bird identification.