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Re: hummingbirds, bees, and colors; romantic mockers; mute swans
hey, this pollinator thing is turning into a pretty neat thread...
on 04-20-2003 at 21:55, Josh wrote:
>The research Gary referred to showed that hummingbirds can be
trained to visit any flower color, but since bees flock most heavily to
blues, purples, and yellows, the hummers find less nectar there, and more
stinger-armed competition, and so spend most of their time visiting reds.<
uhhh...being a bit presumptuous there, Josh. actually, that's a different
paper where specifically Anna's hummers were trained to discriminate between
colors. i was referring to something else (Grant and Grant, 1969 i think)
but another experiment using 5 different-colored sugar water solutions with
Ruby-throated hummers showed no significant color preference. while we're
talking about pollinators and vision and all that sorta research,
Black-chinned hummers were demonstrated in 1980 to see in the near-UV range;
subsequent research has shown hummers possess the necessary retinal pigments
(as do a number of other bird species that have been investigated, including
chickens and pigeons) for tetrachromatic vision (seems that some salamanders
were demonstrated to have this ability, too. i have a tendency to gloss over
most all but the bird stuff. go figure.) for the hummers (maybe all of the
Aves,) the entire world might look something like a "blacklight" poster does
also, many of the non-red flowers produce as high or higher sugar
concentrations as the red. Brazilian Sage (Salvia guaranitica) has blue
flowers (there are a number of varieties ranging in color from sky blue to
purple) and averages ~30% (or more) sugar concentration. hummers wear this
stuff out here.
by comparison, Red Wal-mart Sage (Salvia splendens, pick your fav. cultivar;
this year's selection here is "Sizzler") avgs. ~18% sugar content.
in So. Calif. Tree Tobacco (Nicotiana glauca) is a common (naturalized) weed
that produces a proliferation of tubular yellow blooms. hummer gardeners
there cultivate it because of its attractiveness to the birds. (i'll be
giving it a try this season.) in So. Louisiana it gets 8' tall and literally
has hundreds of blooms per plant.
according to one fairly well-respected ornithologist-type person who happens
to garden for hummingbirds, wintering Black-chinned hummers in LA (that'd be
Louisiana, not Lost Angels) appear to show a preference for Forsythia Sage
(Salvia madrensis) which produces yellow blooms. Manettia inflata has
creamy, yellow-to-orange tipped blossoms; it's a big hit with hummers, too.
a white cultivar of (Pentas lanceolatas) appears to produce higher sugar
conc. than either its red or pink kin (these are the "old-fasioned" 3' tall
cultivars.) Ruby-throateds here visit the white before either of the others.
an Abelia hedge here attracts numerous pollinators with its white flowers;
hummers, several butterfly spp. and several Hymenopteran spp. keep it busy
while it's blooming.
i gotta go along with the "red stands out on a green background" line of
thinking (for now, anyway.)
and a bunch o' y'all think i'm just obssessed with putting jewelry on these
wicked little birds...
sunset zone 31
"...where is the person, I ask, who, on observing this glittering fragment
of the rainbow, would not pause, admire, and turn his mind with
reverence..." (J.J. Audubon)
----- Original Message -----
From: "Joshua S. Rose" <firstname.lastname@example.org>
Sent: Sunday, April 20, 2003 9:55 PM
Subject: hummingbirds, bees, and colors; romantic mockers; mute swans
> Hi Carolinabirders,
> Added Chipping Sparrow to the yard list, as two perched near the feeders
> but didn't eat much. A Gray Catbird is a new regular at the suet feeder,
> and meowed at me from there while I sat on the ground six feet below
> digging up weeds (Star-of-Bethlehem, yuck!). And lately, two mockingbirds
> have been sharing the suet in a scene that looks more appropriate to
> Valentine's Day than Easter or Passover... Yellow-rumps are into their
> breeding plumage, and singing lustily, but so far no vireos or other
> warblers migrating through Old North Durham. Hopefully they'll all show up
> for the Durham Spring Bird Count next Sunday...
> Some clarifications on the hummers-insects-flower color discussion: *some*
> insects can see the color red, especially butterflies. The main difference
> between butterfly- and hummingbird-pollinated flowers tends to be shape,
> not color; and the two groups do overlap. Where the red color becomes
> significant is in relation specifically to BEES. Bees' vision is shifted
> to the short wavelengths; it allows them to see into the ultraviolet, but
> in compensation reds appear black to them. So flowers which "want" to
> deposit their pollen on birds have red flowers; those which are
> specialized for bees usually have blue or purple flowers, or are yellow to
> our eyes, but have patterns in ultraviolet that unaided vertebrate eyes
> cannot see. The research Gary referred to showed that hummingbirds can be
> trained to visit any flower color, but since bees flock most heavily to
> blues, purples, and yellows, the hummers find less nectar there, and more
> stinger-armed competition, and so spend most of their time visiting reds.
> Back to invasive exotic species:
> On Fri, 18 Apr 2003, Ritch Lilly wrote:
> > On an unrelated note, the number of Mute Swans in our area is either
> > better or worse depending on your point of view. I had a total of 25
> > yesterday as I was out and about. Can someone tell me the status of that
> > bird here locally?
> > Are they protected? Should
> > they be removed? When is such a species determined to be established?
> Can't speak to their status; the only population I hear much about in the
> Carolinas is down there in the Conway/Myrtle Beach/Georgetown zone of SC.
> I don't think they're protected in their own right, but in some places
> they are protected in order to avoid people without hunting permits
> shooting Tundra or Trumpeter Swans thinking that they are Mutes.
> They definitely should be removed, although down here in the Carolinas,
> they're less of a menace; up north they run other waterfowl out of nesting
> habitat, but down here our only common nesters in most places are Wood
> Ducks that don't use the same habitat. Their prodigious wastes have caused
> clam beds to be closed up north, and could lead to closings of oyster beds
> down here; they might also cause serious damage to aquatic vegetation if
> they get common enough. The big question is how? Animal-rights groups get
> their panties bunched up over swans getting shot, and addling eggs can
> only get you so far. In the Chesapeake Bay, where Muties are a major
> problem, they have all kinds of proposals and counter-proposals. Not sure
> which one they're using.
> As for being established, if they are fledging young Muties faster than
> the adult birds are dying off as roadkill or whatever it is that kills
> them, that works for me...
> On Fri, 18 Apr 2003, Paula Jeannet Mangiafico wrote:
> > I wonder what effect the various hurricanes and ice storms in the last
> > years have had on populations of woodpeckers and other birds that depend
> > dead or downed timber?
> I actually tend to see the most woodpeckers around the various waterfowl
> impoundments like Horton's Pond and in many of the gamelands, and along
> the edges of artificial lakes like Jordan, Falls, etc. While the
> hurricanes and ice storms tend to produce *fallen* trees, the impoundments
> and dams flood forests and kill trees but leave them standing, more to the
> birds' liking.
> Good birding!
> Joshua S. Rose
> Duke University
> Department of Biology (Zoology, R.I.P.)