AUTHORS: Luke F. Gray, Dr. Carol I. Bocetti - California University of Pennsylvania
ABSTRACT. Artificial lights attract wild birds during migration and nesting season. Some research has shown changes in reproductive physiology and molting up to one month earlier in captive birds as compared to known data in wild forest birds. Even low light levels at night have shown to trigger earlier Zugunruhe, increased nocturnal activity, and cause an increase in melatonin regulation in birds; which is the primary driver of the circadian rhythm. While effects of artificial lighting have been examined in captive birds, no studies have investigated the effects on wild birds during the winter season. The purpose of this study is to identify the effects of artificial lighting at night on the avian circadian rhythm during the winter months. The conservation concern for this anthropogenic disruption of wintering birds is the energy cost of being active at night. Resident species and overwintering migrants should be gaining fat in preparation for breeding in the spring, so added energy costs could compromise this process. Three dark sites (controls) and three night-lighted sites that have similar avian habitat (forest to open space ratios, < 0.5 ha) but different night lighting conditions were selected for comparisons. In coordination with California University of PA and private land owners, avian recording equipment will be set up at pairs of sites for two-week sampling periods, each at three pairs of sites (six sites total) beginning in late-January. Observations will also be conducted at least two days per week to supplement recordings and validate the sampling method. It is hypothesized that there will be an increase in the species richness and species diversity of birds that are active in night-lighted areas compared to areas without light; and that the average number of minutes that each avian species is active will be greater in night-lighted areas compared to dark areas.
