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06/09/2004
Decorating and Dancing Dude
My wife and I just returned to hot and humid New Jersey after a
few days in hot and dry Las Vegas. Talk about global warming –
the temperature in Vegas ranged up to 107 F and it felt like an
oven upon stepping outside our hotel. Our hotel, the Bellagio, is
noted for its spectacular fountain shows at frequent intervals
during the day and night and also for its lobby’s ceiling. The
ceiling is decorated by a 2000 square-foot sculpture by the
renowned artist Dale Chihuly. The sculpture, which took two
years to complete, consists of over 2000 individually blown
colorful glass pieces attached to the ceiling using a matrix of
steel rods. The effect is to create a colored veil of glass flowers
that is truly impressive and beautiful.
The male satin bowerbird of Australia is a bit more modest in the
decoration of its bower. I believe I’ve discussed the bowerbird
previously but now there’s a new study that deals not only with
his decorations but his song and dance routine. The study relates
to the broader subject of a female’s changing taste in members of
the opposite sex as she matures. Articles by Virginia Morrell in
the April 16 issue of Science and by Bijal Trevedi on the
National Geographic News Web site describe a paper in the
April 15 issue of Nature by graduate student Seth Coleman of the
University of Maryland, College Park and his colleagues. Seth
has shown that female bowerbirds look for different qualities in a
mate as they grow older.
Songwriters often mix sex with the blues, which seems to be
exactly the approach used by the male satin bowerbird, a
strikingly purplish-blue bird with blue eyes and a yellow beak.
He builds a U-shaped bower out of yellowish straw or twigs on a
straw mat and then searches for items to decorate his bower. He
particularly looks for blue items such as bits of plastic or glass,
berries, flowers, bottle caps or feathers. Blue not only matches
the color of his eyes but also is a relatively rare color in nature
(neglecting the blue sky), so a collection of blue items would
attract the attention of a female looking for a mate.
The female inspects the decorated bowers of various males,
taking note of the number of decorative objects and their
arrangements. She apparently has a sense of artistic design,
preferring a more ordered arrangement as opposed to a
haphazard assemblage of items. After evaluating the various
bowers, she then comes back to her favorite bowers and sits in
them while the males do their “buzz-wing-flip” dances.
The buzz-wing-flip is an impressive display of fluffing of
feathers and running back and forth, accompanied by buzzing
vocalizations. The male usually does this song and dance routine
four times. The female isn’t about to be rushed into a quick
decision and goes off to watch other males strut their stuff.
When she’s made her choice she builds a nest and returns to the
winning bower to mate with her chosen one. (One meaning of
the word “bower” is a boudoir.)
Back in 1871, Darwin proposed his theory of sexual selection,
noting that females are attracted to “fancy males”. The male
peacock’s plumage and the songs and dances of various birds
help set the fancy males apart from their lesser rivals. What Seth
Coleman set out to do was to see how females weigh different
“fancy traits” against each other in a three-year study of the
bowerbird in the Australian bush.
There, in New South Wales, he tagged some 90 wild bowerbirds
with colored bands for identification. There were 28 bowers in
the study. He gave each of 14 male bowerbirds 50 strands of
blue plastic and 20 blue plastic tiles. When these males had
arranged these items in their bower, he glued them in place to
keep other males from pilfering them. The other 14 males were
on their own as far collecting items for their bowers but were at
an obvious disadvantage when their bowers were compared with
the enhanced decorations of the first group. Video cameras
recorded the ensuing interactions with the female bowerbirds.
As expected, both younger and older females favored the bowers
of the males given the extra items and returned to watch those
males perform their buzz-wing-flips. But the inexperienced gals
in the 1- to 2-year-old age group weren’t prepared for the
intensity of the buzz-wing-flip and recoiled at all that physical
activity. Smart males would notice this apprehension and tone
down their dances. These young females would invariably
choose to mate with the male with the most heavily decorated
bowers.
On the other hand, the older females not only returned to the
most heavily decorated bowers but also watched closely the
buzz-wing-flips before making their selection of a mate. Being
more mature, they now had the wisdom to realize that the
intensity of a male’s dance, not only his decorative skills, was a
better measure of his fitness and desirability as a mate.
In the end, both young and old females ended up choosing the
same group of top males as their mates. The most energetic
males were also the ones who search out the most objects with
which to decorate their bowers. Hence, the male’s decorative
abilities correlate well with their physical prowess. So, although
concentrating on different “fancy traits”, both young and old
came up with the top mating candidates.
How do maturing women’s changing tastes in men compare with
those of the female bowerbird? Totally lacking any expertise in
this area, I venture the following unscientific assessment of the
situation. It seems to me that the maturing human female’s
choice of a mate or significant other develops in the opposite
direction of that of the female bowerbird. Aren’t younger
women and girls attracted more by the song and dance? I base
this on the screaming and yelling females in the presence of
today’s rock singers and the reported multiple couplings of many
athletes. As women mature, don’t they tend to favor men for
their decorative abilities, actually for their ability to decorate the
women with expensive jewelry etc.? I’ll quit while I’m behind!
I had thought that, after returning from Vegas, I would write
about the subject of statistics and the probabilities of coming out
ahead in the gambling arena. After my disheartening experience
with the slots, I decided that would be too depressing a subject.
Also, the last night of our stay we went to see the show “Jubilee”
at Bally’s. It contained two quite impressive production
numbers, one on the sinking of the Titanic and the other on the
bringing down of the temple by Samson after having his hair
shorn by Delilah. Of course, being Vegas, there was also a
plethora of beautiful women, a large number bereft of any
covering on the upper parts of their anatomies. This may have
influenced my selection of the topic of sex in the bowerbird for
this column.
Lest I leave you under the impression that my gambling activity
was also bereft of any covering (of losses), as we were lining up
to board our plane home, I put two quarters in a slot machine and
received 10 quarters in return. It was the only winning day of
my stay there!
Allen F. Bortrum
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