Delaware Public Media

The forces behind unusual bird sightings in Delaware

May 5, 2015

Every now and then, you might hear of an unusual bird sighting. One example folks in Delmarva might be familiar with are the snowy owl sightings at the end of 2013.

Wildlife scientists call these birds and other animals that don’t belong in Delaware “vagrants.” One recent example was the burrowing owl, which was spotted at the Bombay Hook Wildlife Refuge in April.

The burrowing owl tend to reside in the southwestern United States and in Florida.

Anthony Gonzon, a DNREC scientist who catalogs these avian vagrants, says that there could be a number of reasons why a non-native bird appears in Delaware.

 

“Birds that migrate are often at the mercy of the weather," said Gonzon. "If they are moving at night and a storm system might come through, they might be blown off a few miles and sometimes, hundreds of miles.”

Other factors also include population size and the availability of food resources.

Gonzon added that it’s hard to link factors like climate change to these vagrant sightings, especially if you’re seeing only a very small number of birds from a species and if some migratory species are already prone to wandering off course. However, it’s possible that an increase in coastal storm activity, influenced by the changing climate, could play a role in blowing birds off-course.

Gonzon, who is an avid birder himself, said that seeing a vagrant is a very special experience.

 

"Taking the time to observe a vagrant, to identify its different fieldmarks and behaviors, and see something that in the end, not a whole lot of people really get to share that experience," said Gonzon.

 

If you have an unusual bird sighting you'd like to share, tell us at iSeeChange.org. Delaware Public Media has recently partnered up with iSeeChange, a community climate change journal and national radio initiative that collects and investigates your observations and questions about the forces that influence our environment.