(female narrator)
William Rowan was an eccentric
and talented man
who had many interests,
including art, writing,
nature, and science.
But perhaps his greatest
passion was birds.
Originally from Switzerland,
he immigrated to Canada
in 1919 to pursue a career
as a biologist.
For Rowan,
the Canadian wilderness
presented a highly
under-explored
outdoor laboratory filled
with biological discoveries
waiting to be made.
He was especially curious
about bird migration:
the annual journeys
each spring and fall
between breeding
and wintering habitats.
What was it
that triggered birds
to fly such great distances
every year?
How did they know
when to go
and when it was time
to return?
Leading theories of the time
suggested that temperature
and barometric pressure were
the key environmental cues
that birds used
to calibrate
the seasonal changes
in their biology.
Rowan saw things
differently.
[click]
In 1924,
Rowan accepted an offer
from the University of Alberta
to establish
a new zoology program.
It was there
that he hypothesized
that changing day length,
not temperature or pressure,
was the key
environmental factor
that triggered bird migration
and reproduction.
Further, he reasoned
that if changing day length
in any way affected
the migratory impulse,
it must do so through
the seasonal growing
and shrinking
of the gonads.
Rowan was not the first
biologist to consider
the importance of photoperiod,
but he would be the first
to directly test
it's role in animals.
He devised an experiment
involving a small population
of captive birds
that would be housed
in two outdoor aviaries
during the winter.
The control group
would be kept un-manipulated
to observe and use
for comparison
with the experimental group.
The two aviaries
would be identical.
However, the experimental cage
would also have electric lights
that would be left on
into the winter nights
to simulate the increasing
length of days
birds would experience
in spring.
This pioneering experiment
would make Rowan famous.
But it didn't come easy.
University of Alberta president
Henry Marshall Tory
had very different ideas
about science.
For Tory, science belonged
in the lab and only the lab.
In the 1920s zoology
was focused on lab studies
of invertebrates, fish,
and amphibians.
Many regarded studying birds,
especially in the field,
as a foolish
scientific pursuit.
It's a waste of time.
(narrator)
Tory repeatedly discouraged
Rowan and gave stern warnings
to give up on his
ornithological research.
Fortunately for science,
Rowan didn't listen,
and he carried out his
fieldwork in secrecy.
As the nights got longer
and the temperatures dropped,
he made his day length
experiment a reality,
working in secrecy
on his own property
on nights
and weekends.
The bird he chose to work with
was the dark-eyed junco,
a common wintering songbird
in Alberta
that migrated northwards
each spring.
Juncos were
an easy choice,
as they were abundant
in small flocks,
easy to capture,
and thrived in captivity.
The experimental juncos
received electric light
well into the night
for three months,
with the duration of light
increasing five minutes
per day to simulate
spring and early summer.
Except for the
artificial lights,
the birds lived
in winter conditions.
In fact, it was
an especially cold winter,
even by Canadian standards.
Every two weeks, Rowan recorded
behavioral observations
and measured the size
of individual birds' gonads.
And just as Rowan
had hypothesized,
the increasing light caused
the experimental juncos' gonads
to increase in size.
By the end of the study,
they courted and sang
as if it were spring.
[chirping]
Funding to purchase and make
this educational production
accessible was provided by the
U.S. Department of Education:
PH: 1-800-USA-LEARN (V)
or WEB: www.ed.gov.
