Characteristics of avian mortality at a north Florida television tower: A 29-year study

The study of birds killed at the WCTV television tower in north Florida over a 29-yr period is one of the longest of its kind. A total of 44,007 individuals in 186 species was collected, and over 94% of the total number of individuals were Neotropical migrants with the Red-eyed Vireo (Vireo olivaceous) the most frequent. Two factors changed during the study period: tower height and scavenger control. Analysis of these factors suggest that towers approximately 94 m or lower may not pose as great a threat of avian mortality as caused by towers 200 m or greater. Absence of scavenger control corresponded with a 71% decline in the number of individuals found beneath the tower. Any study of avian mortality at communication towers must directly address the problem of removal of injured and dead birds by scavengers to make an accurate measure of mortality.