Regular ambient temperature monitoring provides data used to help calibrate thermal imaging videos as part of research into measuring stress levels in wild birds.
Researchers at Glasgow University are developing a new,
non-invasive method of measuring stress in wild birds using thermal
imaging. This new technique avoids the difficulties of having to
take blood samples to look at plasma hormone levels. When animals
are under physiological stress, their blood gets diverted to the
body core. This results in a cooling at the skin surface, which is
what the researchers are studying as a new way of assessing stress
The absolute temperatures measured by the thermal imaging
cameras are affected by a number of factors, including air
temperature and humidity. The analysis software is designed for
this data to be inputted, but in practical terms it is inconvenient
to collect, and can introduce error. An alternative method is to
provide a reference temperature from a body with known reflectance,
within the field of view, against which the whole image can be
calibrated. A Tinytag temperature
probe covered in insulation tape is perfect for this job.
accompanying probes are being used in this way with cameras at
a number of research sites in the area surrounding the Scottish
Centre for Ecology and the Natural Environment (the University of
Glasgow field station), on the eastern bank of Loch Lomond.
Paul Jerem is a Researcher on the project whose group has been
using Tinytag loggers to successfully monitor ambient temperature
for many years. Paul comments, "As the loggers were already
providing the kind of data we needed for calibrating the thermal
image videos, it was suggested that I use them. Their accuracy and
the ease of use of the software are the main reasons I'm happy
In order to increase stress levels in the birds, a stuffed
sparrowhawk is sent down a length of clothes line, picking up speed
as it approaches a busy woodland bird table, simulating a natural
attack. The thermal cameras record changes in bird body
temperatures as the perceived risk of predator attack rises. The
study aims to understand how animals are responding to
environmental change, particularly climate change.
The arrow on thermal image above shows the logger probe in
the top right hand corner (the slightly pale rectangle).