Satellite sensor links birders and NASA scientists

Thousands of hobbyist bird watchers are seeing their avian observations put to high-tech use in a new biodiversity study that uses satellite data to monitor changes in bird populations over vast swathes of land.

The birders’ observations were originally part of a 40-year, large-scale survey conducted in the United States and Canada to track changes in songbird populations. Now, their contributions are being given new life as part of a Montana State University research project that tracks how human land use affects bird diversity. They are using vegetation data from a satellite sensor called the Moderate Resolution Imaging Spectroradiometer, or MODIS.

Researchers point out that tracking population changes over large areas can be extremely difficult—for one thing, extracting patterns of changes to birds’ habits can take years, and when you have several hundred types of birds flying around, watching for tell-tale shifts in their environments would be an enormous task.

We wrote about a group in the UK that’s using sophisticated RFID tracking and wireless networks to observe a few dozen birds, but imagine trying to tag thousands of the creatures. It would be expensive and time-consuming, to say the least. Besides, there are thousands of bird buffs out there to do it for free.

So the Montana ecologists analyzed several of the migration patterns documented in the North American Breeding Bird Survey over a period of years and matched that to the data on vegetation change collected by MODIS. Together, the data produced a much more complete picture of how human land use had pushed bird populations along particular migratory paths, and perhaps caused some birds to disappear.  

MODIS, no slouch of an instrument, was also used this month to spot the actively burning wildfires that broke out in California last week. The satellites Terra and Aqua, each of which has a MODIS sensor, orbit the Earth from pole to pole, and together they produce images of most of the planet almost every day. The sensors are beyond their projected design life, however, so while they are likely to stay functional and to continue collecting climate and ecosystem-related data, we don’t know for how long.