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Introduction
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Little
is know about the behaviors and activity within the
roosting cavities of the eastern screech owl (Otus
asio). In this live study we will observe the
behavior of the eastern screech owl inside several
roosts using artificial nest cavities fitted with
small video cameras.
Traditional methods of monitoring roosting cavities
and nest boxes include ascending trees with climbing
spikes, using a ladder, or a pole mounted with a
mirror or small video camera. While these methods
are effective monitoring techniques they tell us
little about the daily and nightly activity. The
monitoring system we designed was used to monitor
the activity continually without any invasive
actions to view the cavities.
In our study we fitted seven artificial owl boxes with a
small infrared video camera and a small audio MIC.
The video cameras used were 1.20 in diameter and 4
long and include (8) infrared LEDs which produce an
infrared illumination source in the 940nm range,
which do not emit any visible red glow. The video
cameras were wired back to a central monitoring
station at a maximum of 1000 from the study area.
The cameras were connected to a multi-channel video
server which recorded any activity within the owl
boxes and sent real-time photo notification upon
motion detection via an Internet connection. Each
owl box is viewed live via a streaming webcam
protocol using a standard web browser.
Owl Boxes
Owl Box w/Camera
Camera
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Study Area |
The screech
owl study area is broken into two areas,
Study Area 1 and Study area 2.
Each owl box is fitted with a small, mini IR
bullet camera and was wired back to the Base
Station about 500 from the study area.
Study Area 1
located in a dry wetlands area surrounded by
mature hardwoods in Westmoreland County, PA.
Five artificial screech owl boxes were
constructed and placed 20 high into mature
hardwoods trees on the edge of the wetlands
area. The boxes were spaced no less than 75
apart, and all boxes were within a 300
study area. In Study Area 2 we
installed two owl boxes in an over
grown farmland field, owl boxes #6 and #7.
Study Area 1 and Study Area 2 are about 300
yards apart. In study Area 1
there is
also an external pan-tilt-zoom (PTZ) which we can
remotely control and view all five cameras for an
outside view.
Study Area
(click on photo to enlarge) Owl Box in Tree
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Real-Time Video
Monitoring System |
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Video Server and
Control Electronics
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The base station
consisted of a two 4-channel video server which was
connected to the Internet. The base station was
placed inside an area with power and Internet
access. We used audio/video baluns at the video
camera and the video server ends, and ran CAT6
outdoor network cable between the baluns. The baluns
were used in order to run long distances of wire to
transmit the audio and video signal back to the
video server without signal loss.
This technique allows a maximum distance of 1000
between the video cameras and video server.
The video server was set up to detect motion from
any of the video camera sources and record the
activity to a SD media card, which was integrated
into the video server electronics. A JPEG still
photo was captured upon the initial motion detection
event and sent via email in real-time to notify us
of the activity within the owl boxes. Photos are
also
archived to a website for viewers to review. The video
stream from each camera could be accessed for live
viewing via a standard web browser.
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Set
full motion detection |
Set door
way motion detection |
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Winter Roosting
Activity |
Screech owls do not
migrate; they maintain home ranges throughout the
winter. During they day light hours the owls will
find a roosting location and will roost until dark.
The winter roosting time period is typically between
October to March. Screech owls are primarily solitary except during
the breeding season. Pairs occasionally roost
together during the winter in hollow trees, nest
boxes, and trees with dense foliage. The cameras
enable us to view the activity inside the owl box
and outside the owl box with the PTZ camera. During
the day the owl boxes are often mobbed by song birds
and occasionally bothered by gray squirrels.
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Caching of Prey |
It is a well known
fact that screech owls will cache uneaten prey items
in cavities. We were surprised at the number of
different species cached and how long the prey items
remained in the owl boxes before being consumed. The
most interesting item was a wood frog (see below)
which was cached on the evening of December 24th
when the air temperature was only 30 deg. F. The
frog was consumed over a 2-week period in stages
over multiple night feedings, and was totally
consumed on January 7th, 2012.
Frog
Mouse
Shrew
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Visitor to Owl Boxes |
The owl boxes do get
the occasional visitor such as gray squirrels and
Carolina wrens during the day and flying squirrels
at night. We have observed unusual behaviors such as
flying squirrels eating cached prey by the screech
owls.
Carolina Wren
Gray Squirrel
Flying Squirrel
Bluebirds Mobbing
Tufted Titmouse Mobbing
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Courting &
Nesting |
Courtship Behavior
Roosting Together
Laying & Incubating
Eggs
Male Feeding Female
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