To all:

I believe this is situation is somewhat common and the norm in my
experience, although Bluebirds in the mix are more of a winter season
association in my opinion, when the Robins and Bluebirds flock up after
nesting.

Everyone is familiar with roving bands of Parids (Chickadees, Tits and
Nuthatches (Sittidae)). In the colder season you often will get other
smaller birds who associate with these bands. This usually includes
Yellow-rumps (Myrtles in our area) as well as a creeper or two in the mix.
Sometimes Kinglets. I believe Rick is right and it does have to do with food
to some degree, but also safety in numbers/more individuals to sound a
warning as well as leading others to food sources in scarcer seasons.

I have found that Bluebirds often join these groups in the non-breeding
time. The bigger of the two thrushes that flock up and winter in the
"woods," the Robins, do not join these groups. But they are often there in
the woods in groups, just not closely associating with the smaller birds.
Usually, in my experience, the Robin flocks at this time can number quite a
few birds, 25 to 100, while the Bluebirds are usually only a handful, 5 to
10, so maybe if there are not too many of them they fit in with the roving
bands albeit a bit bigger in size. And in some cases, a Downy will join in
tagging along with the group.

But if you run into these bands and there are wrens, etc., present they will
scold you too and appear to be with the group; but they do not follow the
group when it moves on.

Both the Yellow-rumps and the Bluebirds are more reliant on berries at these
times, especially dead of winter and that probably influences where and
where they join these bands. This supports Fred's observation of these two
together as I assume they are following along together in search of berries,
as well as Rick's comments on food availability.

Unlike most warblers, Yellow-rumps are a flocking bird outside the nesting
period, including in migration. I am not referring to mixed groups of
feeding warblers in migration like at a fallout, but solid groups of all
Myrtles flying together. They often feed on the ground in winter in open
situations in large flocks and I have heard accounts they do this with
Bluebirds, Pipits and Palm Warblers (another flocking warbler), even on
beach areas in winter. I have not personally seen them with Bluebirds in
this situation however, only in more wooded situations with Bluebirds and
with Parids at the same time. I have seen them with only (multiple) Palms on
the ground in relatively open sites. Don't know about Audubon's Warbler in
this regard. The Palm is another "flocking" warbler outside breeding
periods.

I see Andy has joined the thread as I type and added Juncos. Fits in with
the ground feeding.

Mike O'Brien
Fairfield, Adams Cty, PA

On Tue, Nov 10, 2009 at 5:06 PM, Rick Sussman <> wrote:

> Fred,
>  Though I don't see this now as often as I used to when I lived in Ashton,
> I believe it is an association based on food availability.This time of year
> when both birds are around in good numbers, the shared food supply is just
> beginning to get scarce. In my yard now I have the last remains of the years
> wild grapes and Virginia Creeper berries, both foods of preference which I
> find them both eating. In Ashton, they would also congregate at the poison
> ivy berries (I don't have that much here). I have also seen lots of Cedar
> Waxwings around with the local bluebirds, eating pretty much the same
> things, though they also eat a lot of Bradford Pears now.
>
> Rick Sussman
> Woodbine (Virginia Creeper), MD
>
>
> the apparent co-mingling of E. BLUEBIRDS
> nd YELLOW-RUMPED WARBLERS. A large elm in the neighbors yards held a small
> roup of bluebirds, and in the same tree were the warblers. As the bluebirds
> lew to other sites, the warblers followed. Then, on to another location,
> arblers in tow. This is not the first time I've seen this behavior...anyone
> now of this or witness this symbiosis?
> Fred Burggraf
>
>
>
>
> -----Original Message-----
> From: Fred Burggraf <>
> To: 
> Sent: Tue, Nov 10, 2009 4:49 pm
> Subject: [MDOSPREY] Hermits, Blues & Rumps
>
>
>
> My woods have filled up with HERMIT THRUSHES of late...each day I hear a
> chorus
> f clucks and chucks from most quarters of my property. Is this the case
> tatewide? (I'm here in SE Charles Co.)
> Yesterday was quite birdy in my neighborhood, with hosts of ROBINS and
> CEDAR
> AXWINGS. I also noticed a "partnership" that I've seen before but that I
> don't
> ecall ever being discussed on Osprey: the apparent co-mingling of E.
> BLUEBIRDS
> nd YELLOW-RUMPED WARBLERS. A large elm in the neighbors yards held a small
> roup of bluebirds, and in the same tree were the warblers. As the bluebirds
> lew to other sites, the warblers followed. Then, on to another location,
> arblers in tow. This is not the first time I've seen this behavior...anyone
> now of this or witness this symbiosis?
> Fred Burggraf
> entsville, MD
>