Video summary
The speaker, Tom Collett, reflects on his experiences studying the visual behaviors of flies, particularly focusing on their pursuit chases and how they navigate space. He describes a specific type of chase where a fly moves rapidly away from a stimulus and then returns slowly to the same location, noting that there is no direct correlation between the length of the excursion and the accuracy of returning to that spot. This observation led researchers to hypothesize that flies are not simply memorizing distances but are instead using visual cues related to the angle of an object relative to their own body. To test this, they conducted experiments where a board was moved away from the fly's starting position; the results showed that flies would fly back until the image of the board subtended the same angle in their vision as it did when they left, suggesting they rely on angular size rather than absolute distance for navigation.
Further investigations explored whether these chases were driven by magnetic fields or purely visual mechanisms, with evidence supporting the latter. The researchers also examined how flies behave in more naturalistic settings, such as an ecosystem box filled with flowers, where they observed that flies maintain a specific orientation relative to their surroundings while moving. This ability allows them to remain stationary or move backward and sideways effectively, enabling them to easily spot and intercept small targets. These findings highlight the sophisticated spatial awareness of flies, which allows them to manipulate their flight path to keep visual references constant regardless of their actual movement direction.
A significant portion of the research focused on sexual behavior, specifically how male flies use vision to locate females. The speaker explains that males typically decelerate and land when they spot a female, whereas if they are already pursuing one, they accelerate rapidly to close the distance. This behavioral difference underscores the critical role of visual input in mating strategies. Additionally, the study revealed anatomical differences between male and female flies; males possess a larger field of view, which is advantageous for scanning for mates, while females utilize their vision more effectively during interactions with other females. These distinctions demonstrate how evolutionary pressures have shaped the visual systems of different sexes to suit their specific behavioral needs.
In conclusion, the symposium presented a fascinating look into the complex world of insect vision, blending rigorous experimentation with observations of natural behavior. The research team found great joy in these studies over several years, noting that the work was less stressful than modern academic administration might suggest. They also highlighted advancements in technology, such as devices that enhance visual capabilities for further study, and mentioned collaborations with institutions like the University of York and researchers like Simon. Ultimately, the talk emphasized that while flies may seem simple, their visual processing involves intricate calculations regarding angles, distances, and orientations that allow them to thrive in dynamic environments.
Read the full video transcript
and so
I was asked to talk about uh my
experiences on my 21st came and he left
a very hidden verbally and that was in a
very stateless
uh
probably the students
were similar
um
[Music]
uh and I have always been a really great
for my previously persuaded me to stop
doing that and to start doing that which
is much more fun because in the outside
world and you can translate Behavior
pretty
uh easily in what's happening
well
so we worked on
public lies
and one of the flavors who wrote
um was
Irish stateless Genex and if you really
need to
many uh
groups or arts or anywhere if you see
these things
but every now and then they could dance
I hope they hope will be your neighbors
and it very rarely is amazed so then
they come back to the same place
uh this is a kind of Chase that they do
so there it starts and then it was very
fast
and it is
up and comes back and he goes very
slowly
uh so one thing we wondered about was
I would get that in the same place
so we found that
so here's a whole function with chases
and this is here and this is the length
of the exertion
yeah
and there's no relationship between the
length of the Excursion and English how
accurate the article in that same place
so that made us Wonder
well there's some visual information
that they might be picking up around
really
oh
the hook inside and we
tested that by using a large Port that
we placed
with be close to where these flies were
found
and then we moved the board away
and
if you look at this you can see the
trajectory
uh so the board is moved during this
prostitution then it goes away and as a
useless Chase and then it comes back I
mean the position relative to the board
if you choose this thing is as a similar
distance to uh we we where the board was
here
so this should work here you can see
that
distance it's more it's the same
so
we suppose that what happens is that
they have learned
the size of this towards and then they
fly back until the image of the board
sometimes the same angle that you did
when they left
and obviously there are many experiments
that you could do to test this more
finally what that's not so the next
question we had with what device with a
reference was about their
the chase itself
opposite control its Pursuit for
potential magnets and for that we use
patients so the target is pretty short
but you should have
and
yeah
you can see what's the why is
doing
so it's not trying to trap because it's
going Beyond it's doing
course
difference
we could get some experimental evidence
that was supposition
I
putting a key at the end of it makes it
cotton and then when we he was shot
because
the
he stops here
and one is where the fly starts its
interception of course and of this
region there's no visual information at
all and it doesn't
about that
so that
seems to be a reasonable evidence but it
it does plan an Inception of course
so
we then
looked at a difference
and we made a sort of ecosystem
box where there were flowers and
they live happily in there
forward what they did in this
uninterrupted situation and what we did
was quite interesting
wow so this is
an example of
oh just flying around but what is really
nice is if you look
at this bit of the
eventually you can see because it
maintains the same orientation with you
sideways or want to do that we can move
backwards
and that means the will itself is
stationary or a threatened and they can
easily pick up any small Target that
there is
so popular has been a lot from this
position kind of this sideways backwards
forwards upside down and play uh
and Mike then went home
and she found that the
allies are very much better but seeing
women of emails
and you can see that here so
so
10 degrees on a male just is a fact he's
a retina whether it's 10 degrees of a
female is about
and they make the rails make good use of
its additional
security
when they interact with females
so
uh is
a male a person who basically wants to
pee and you can see that it's
decelerates
uh and then lands
but you can spots a female then it does
the reverse so here it's accelerating
and this mission is not enough land head
to head and tail
and while Israel was
uh
now for me this man was just looking on
well
we had a lot of fun doing this about
five years or so
[Music]
um
that's Rockets
huh
days were very relaxed
like
before four o'clock it's the right time
to stop doing silence and that you could
go home and do the other things
the University of life was not stressful
but then it's not Administration said
what one should do
uh excuse me back then it was bad
it's an absolutely
yeah
especially now in circles have been
found in the cuts in New York Times the
packages in Business University working
with regards from q2w thanks very cheap
and he's out of here
visual scientists
um well Simon and that area were wearing
the device that gave an even better
vision
so there's lots of
um
but