Published: October 10, 2008 10:38 pm         

DNR blames Tucker bird deaths on fog

HAMBLETON, W.Va. — An investigation of more than 500 dead birds found last month at Tucker County High School found that the birds died from crashing into the building, according to the West Virginia Division of Natural Resources.

As part of standard procedure, officials from the West Virginia Department of Health and U.S. Department of Agriculture tested sample specimens for both West Nile virus and avian influenza. All samples tested negative for both diseases.

An additional sample was sent to the Southeastern Cooperative Wildlife Disease Laboratory in Athens, Ga.

Officials collected the majority of the birds near the outside walls of the school and from the roof. Some were collected from the adjacent parking areas and athletic field. All evidence was consistent with a large-scale collision event.

DNR and the U.S. Fish and Wildlife Service are working with the Tucker County Board of Education and Allegheny Power to remedy the situation at the school. They will modify lighting to make the site less attractive to migratory birds. The site will be monitored for additional mortality for the remaining 2008 migratory period and into future years.

The peak of neotropical songbird migration occurs in late September and early October and is concentrated along mountain ridges. Large bird strikes are not uncommon throughout North America during this time frame.

Events like these occur when several environmental conditions occur simultaneously in proximity to a lighted man-made structure.

These conditions typically include dense fog, southerly winds and a dome of artificial light surrounding a structure. The event can be further amplified by a period of rain prior to the event that concentrates birds by delaying migration.

Three days of rain prior to Sept. 29 were followed by a passing cold front that generated southerly winds and ideal migration conditions. These birds headed south, encountered dense fog along Backbone Mountain, were attracted by the dome of light surrounding the school, became disoriented and began to circle the structure, crashing into windows and the outside walls. Some birds may have died from exhaustion from constant circling.

Similar events have been documented in West Virginia in the past.

Officials recovered 501 birds representing 31 species at the site.

Seven birds recovered and were released alive.