13 replies to this topic

[sailormom64]

Took a picture of this finch, not sure if it is a house finch, I just returned to South Carolina from Washington and this doesn't look like the house finches I was taking pics of there.... just checking guys! I wasn't sure if they change "clothes" for the winter like some other birds do. Thanks in advance. (I know, me and my house finches!)

[TheBillyPilgrim]

Individual birds don't look much different between seasons, but they are extremely variable as a species in the extent of red (or other colors) they show. There's also a bit of geographic variation, since they are so widely distributed. This just looks like a more lightly male.

[sailormom64]

Thanks! I know the streaking on the belly wouldn't make it a purple, right? I just thought overall color didn't look quite right and wondered if they change. There were two of them, both males, that looked this way at my feeder. Since I have been back I haven't seen any of the bright strawberry colored house finches.

[TheBillyPilgrim]

Yep, the streaking below rules out Purples.

[BigOly]

I guess all I have is another question. Here in Baja Sur, many House Finches are yellow/orange in the winter.


By late spring-early summer most of the House Finches are reddish. I don't know what's up with that.

[TheBillyPilgrim]

I guess all I have is another question. Here in Baja Sur, many House Finches are yellow/orange in the winter.


By late spring-early summer most of the House Finches are reddish. I don't know what's up with that.

My guess is you've got migrating populations, so some birds are different between seasons. These guys don't change color, as far as I'm aware (i.e. a yellow variant is yellow its whole life and a normal, red finch is red it's whole life).

[psweet]

It wouldn't surprise me if House Finches changed color -- the yellows and reds are composed of carotenoids, and the precursors for those are obtained through diet. However, I agree with BillyPilgrim about migrating populations, since the molt is in the late summer and early fall, and thus there shouldn't be any new feathers between winter and spring. (Unless the molt timing given in Pyle doesn't apply that far south ...).

[TheBillyPilgrim]

It wouldn't surprise me if House Finches changed color -- the yellows and reds are composed of carotenoids, and the precursors for those are obtained through diet. However, I agree with BillyPilgrim about migrating populations, since the molt is in the late summer and early fall, and thus there shouldn't be any new feathers between winter and spring. (Unless the molt timing given in Pyle doesn't apply that far south ...).

I looked this one up and it appears I was way off...it is documented that House Finches actually change color with age, primarily going from orange or yellow in their early years to red in their 2nd or 3rd year. One study had 94% of its Yellow/orange birds change to red by the 5th years, while only 3% changed from Red to Orange (and none from Red to Yellow). Strange that that isn't really mentioned in field guides.

[psweet]

Cool, BillyPilgrim -- did those references hint at a mechanism?

[TheBillyPilgrim]

Cool, BillyPilgrim -- did those references hint at a mechanism?

It seems like its not entirely understood but primarily due to genetic and hormonal factors. Diet seems to have an impact, but its likely more of a limiting factor (i.e. birds with insufficient dietary supplies of the precursors for a pigment will have altered pigmentation, but given sufficient dietary supply the other factors seem to explain most variation). They made a good point that wild populations aren't likely to experience enough variation in diet between individuals to account for the larger number of yellow and orange variants in some areas (like BigOly's example).

[BigOly]

I just always figured that when these birds got down here and were yellow/orange they turned red after eating from my feeders for a couple months. I guess I'm way off.

[psweet]

Once a feather has grown in, the only things it can do are wear down or fade. Going from orange to red would require orange tips to wear off, showing the red below (not impossible, I suppose).

[TheBillyPilgrim]

Once a feather has grown in, the only things it can do are wear down or fade. Going from orange to red would require orange tips to wear off, showing the red below (not impossible, I suppose).

In the case of House Fnches, the entire feather is colored the same so wear doesn't factor into the change. I think the best assumption here is that BigOly is seeing different populations at different points of the year due to migration.

[sailormom64]

I think the yellow one is just as pretty, if we didn't know he was "supposed" to be red!