The changing trend in songbirds' abundance, variety and physical condition in Connecticut's forestry habitat

Abstract

Songbirds are facing rapid population declines in Connecticut due to habitat loss. Man-made habitats such as powerline corridors are one of the few remaining ideal habitats for songbirds in the state. This study aims to determine if the abundance and variety of song-birds in four selected forests (i.e. Naugatuck State Forest, Sharon Audubon Society, Miles Wildlife Sanctuary, and Great Mountain Forest Species Variety) in Connecticut show patterns of decline from 2005 to 2014. This study also compares the physical condition of songbirds captured along a powerline corridor in the Naugatuck State Forest with those captured in the rest three non-fragmented forests in Northwestern Connecticut using Mann-Whitney U tests. Weight and wingspan are used as indicators of bird physical condition. The results demonstrate that the three non-fragmented forests experienced a steady decline in the variety of songbirds between 2005 and 2014. In addition, songbirds' abundance decreased steadily during the same period, except that of the ovenbird (Seiurus aurocapilla) and wood thrush (Hylocichla mustelina) in Miles Wildlife Sanctuary. The results from the Mann-Whitney U test have shown that after sex- and age-controlled features, the physical conditions of the three selective songbirds - veery (Catharus fuscescens), ovenbird, and wood thrush - tend to be better in the Naugatuck State Forest than in the three non-fragmented forests - Sharon Audubon Society, Miles Wildlife Sanctuary, and Great Mountain Forest Species Variety. Given are recommendations on how to protect the shrubland habitat along powerline corridors and how to create the shrubland habitat in non-fragmented forests.