The evening grosbeak, a noisy and charismatic songbird, once arrived at Oregon State University in springtime flocks so vast an OSU statistics professor estimated there were up to a quarter million of the birds on campus daily.
The evening grosbeak, a noisy and charismatic songbird, once arrived at Oregon State University in springtime flocks so vast an OSU statistics professor estimated there were up to a quarter million of the birds on campus daily.
Gone is the era, however, when the birds were so numerous that students, staff and faculty felt the need to take cover from grosbeak droppings.
An Oregon State study published in the journal Diversity shows the number of evening grosbeaks using the campus as a migration stop-over site has gone down an average of 2.6% per year over the last four decades. The bird has been experiencing decades of decline throughout its range, which includes most of the United States, said Douglas Robinson of the OSU College of Agricultural Sciences.
It’s not yet known, Robinson said, why there are fewer evening grosbeaks than there used to be. It could be related to disease, climate change or shifts in land use, or some combination of those, or a different factor that scientists have yet to uncover.
Read more at: Oregon State University
Male evening grosbeak (Photo credit: Douglas Robinson, Oregon State University)
