User:J-smoothe06/sandbox

Ecology Topic

Environment

Ecology is the interaction between plants the environment and animals.

Areas:

• Biomes
• Population
• economy
• Landscape

"We developed a behavioral assay to test quick decision-making under diurnal light conditions by releasing a bird into an experimental arena in a way that it moved in one direction until it was forced to make a choice of going right or left. Our main motivation was to identify lights that would lead to avoidance responses ultimately to minimize collisions with man-made objects and/or vehicles; consequently, we used a single-choice (also known as no-choice) design (Withers & Mansfield, 2005; Van Driesche & Murray, 2004) in which one side had a light turned on and the other side had a light turned off. Single-choice designs have been shown to perform better than two-choice (i.e., both sides with lights on) or four-choice (i.e., each option with lights on) designs to measure avoidance behavior."

Methods: We found lights that approached our specified conditions at Super Bright LEDs Inc. (St. Louis, MO, USA): five mm through-hole format LEDs with peaks at different wavelengths: 380-nm ultraviolet (RL5-UV0230-380), 470-nm blue (RL5-B2430), 525-nm green (RL5-G7532), 630-nm red (RL5-R8030), and “cool” white (RL5-W18030). The bird was removed from the bag and placed into the first chamber of the experimental arena. We tested five different light wavelengths and an individual cowbird was exposed to each wavelength only once. We randomly assigned the compass direction of the arena (east or west), and the left-right orientation of the light-on and light-off conditions, such that each of the four light-on orientation (right, left) and arena compass direction (east, west) combinations was repeated five times with five different birds.

Results: Cowbirds significantly avoided the sides illuminated by the 470-nm LED (16/17, P = 0.000137) and the 630-nm LED (13/17, P = 0.0245) (Fig. 5). Cowbirds did not exhibit significant preference or avoidance for the 380-nm LED (9/17 avoided side with light-on, P = 0.500), the 525-nm LED (7/16, P = 0.773), or the “white” LED (8/17, P = 0.685) lights. our findings suggest that brown-headed cowbirds significantly avoid LED lights with peaks at 470 and 630 nm, but do not necessarily avoid nor prefer LED lights with peaks at 380 and 525 nm or broad-spectrum (white) LED lights. Overall, LED lights peaking at 470 nm could be a good candidate to enhance the chances of cowbirds evading man-made objects, thereby reducing collisions, at least under daylight conditions. Our study focused on lights, but it raises the interesting possibility that birds might also show avoidance behavior to certain wavelengths in bright painted surfaces. For instance, a correlational study using public records of bird-aircraft collisions found a negative association between brighter aircraft fuselage color and bird strikes.