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Described below are some new ways we are going about studying social
behavior.
Voice Recognition
| We now collect observational measures of singing and social
organization using IBM ViaVoice speech recognition technology. Spoken information is sent by wireless mic to the lab, received by ViaVoice, transcribed into text, and downloaded into a database. The database checks for errors, organizes and summarizes the
data all automatically. It has proven to be an incredibly accurate system that provides us with a hands-free interface and removes manual data recording and data entry time. For more information on the system, click here. And for even more information, click
here. This capability has allowed us to vastly increase the quality
and quantity of behavioral data we collect and consequently has created the
ability to investigate the development of social/communicative
behavior in realistic social settings. In our
first large flock study over an 8 month period four observers collected
approximately 32,000 data points and entered the data in a data base.
Today four observers can collect and analyze a comparable data set in about
20 days. The voice recognition data is all time stamped so that we can
identify patterns of action and reaction that are related in time. The
continuous flow of time stamped data led us to develop a new statistical
tool to identify recurring sequences of behavior not easily seen with
traditional statistics (see below). |
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Modified Triadic Census
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Studies of learning or the development of behavior
typically measure the behavior of one or two individuals at a time but
learning in nature commonly occurs when multiple individuals are present and
interacting with each other as the eavesdropping literature shows.. To
address this real world problem
we use a modified
triadic census that parses behavioral data from a flock into interactions
among three individuals at a time. The figure on the right shows all
possible interactions between three individuals and is taken from Wasserman
and Faust (1994). Unlike previous implementation of the triadic census we
use the occurrence of a particular behavior as an initiating event for the
formation of a triad and require that subsequent events occur in immediate
temporal proximity to be considered part of a triad. The implementation of
the triadic census produces a distribution of triad frequencies that is very
sensitive to individual differences and variation in social structure. The
figure below shows one such distribution created after male singing to
females. |
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female)dir.jpg)
The figure on the left shows the triads created when the initial event
was a male singing to a female. The X axis shows that only 11of the 16 triad
types were present. The Y axis, on a log scale, shows the frequency of the
triad types. It can be seen that the most frequent triad, the first bar on
the far left, was when a male sang to a female and nothing happened. It can
also be seen that the three next most frequent events are (from the left)
triad types 3,5,7. In all of these triads after the initial song the male
either sang to another bird, was sung to or interacted reciprocally with
another individual. While not shown in this figure we can then break out the
exact type of interactions within the triads. When we do this we see that
virtually all of the subsequent interactions in the 3,5 and 7 triads are
with males. Thus, in this particular flock, when a male sang to a
female the most common event to follow was male-male singing. |
Robotics
| This is Selfish Jeanne. She is a robotic female
cowbird programmed to move her head, move back and forth along a perch and
to wing stroke. She will be used to interact with live cowbirds. Robotics
give us the power to have control over one aspect of a dynamic system.
Click here start 2.8MB movie of Jeanne |
 
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Computer Simulations
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Requires Macromedia Flash Player |
In collaboration with Anne Smith, a former PhD
student in our lab, we have begun
designing agent-based simulations where individual simulated organisms are
programmed with a series of behavioral rules and then allowed to interact
with one another. The patterns in these interactions then can be documented.
Such simulations will be used to test the rules of social interaction that
cowbirds may be using that produce the social profiles we have documented in
the aviaries. Two animations of the Virtual Observer simulation showing
male and female organism assortment patterns under
high and
low bias bias to moving toward same sex individuals (males are black,
females are brown). Requires Quicktime 5 or 6
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Hand Raising Baby Birds
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Egg-to-egg development
Although we have hand reared cowbirds in the past, we
required the assistance of a host species to feed the babies for the first
five days. In the left frame a baby cowbird is fed by a canary. This year the lab tried and succeeded in raising babies from the
egg, straight from our incubator. The eggs were obtained from females in our
aviaries. The females lay eggs in nests that we build. Pictured to the right
above
is one such nest. The speckled egg is a cowbird egg. The other two "eggs"
are yogurt covered peanuts. Female cowbirds prefer to lay eggs in nests that
contain eggs. The yogurt covered peanuts work very well as substitute eggs.
Before laying her own egg the female will remove a host egg as pictured to
the right.
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| The aviaries are observed extensively during the breeding season so
we have extensive social histories on each individual female and her mate. We have found that female fecundity and egg viability
varies greatly across different social environments. We now have the
ability, using hand rearing and DNA analyses, to extend individual and group
social histories across generations: to see how the growth and behavior of
the young correlate with the social competencies of their parents or their
social group. |
Pictured to the right is an incubator tray with each row showing the
egg output from 5 of our aviaries spanning a 12 day period: all of the
aviaries housed about the same number of females but egg production varied
widely. After the eggs hatch, the babies are fed every 15 minutes from
6:00am to around 11:00 PM
Pictured below is the same baby cowbird photographed on days one, ten,
fifteen, twenty one and forty eight. |
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Day 1
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Day 10 |
Day 15 with leg bands OD (orange dark blue)
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Day 21
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Day 48 a female
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 Day 79 for OD & day
72 for LY (light blue yellow) a male. LY is attempting to sing to OD. |
Recording Babies
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We use small wireless microphones (FMR-150, Telex Communications) to obtain
high quality recordings of infants' prelinguistic vocalizations. The
microphone and transmitter are fitted in overalls that the infant wears
throughout the play session.
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