Anthropogenic contaminants could alter traits central to animal behavioral types, or personalities, including aggressiveness, boldness and activity level. Lead and other toxic metals are persistent inorganic pollutants that affect organisms worldwide. Metal exposure can alter behavior by affecting neurology, endocrinology, and health. However, the direction and magnitude of the behavioral effects of metal exposure remain equivocal. Moreover, the degree to which metal exposure simultaneously affects suites of correlated behavioral traits (behavioral syndromes) that are controlled by common mechanisms remains unclear, with most studies focusing on single behaviors. Using a model species for personality variation, the great tit (Parus major), we explored differences in multiple behavioral traits across a pollution gradient where levels of metals, especially lead and cadmium, are elevated close to a smelter. We employed the novel environment exploration test, a proxy for variation in personality type, and also measured territorial aggressiveness and nest defense behavior. At polluted sites birds of both sexes displayed slower exploration behavior, which could reflect impaired neurological or physiological function. Territorial aggression and nest defense behavior were individually consistent, but did not vary with proximity to the smelter, suggesting that metal exposure does not concurrently affect exploration and aggression. Rather, exploration behavior appears more sensitive to metal pollution. Effects of metal pollution on exploration behavior, a key animal personality trait, could have critical effects on fitness.
Metal pollution gradient exploration scores
This file contains novel environment exploration scores for great tits residing at study sites located across a metal pollution gradient in Antwerp, Belgium, in 2017. The study sites were: Fort 4 (F4), Fort 5 (F5), Fort 6 (F6/CDE), Fort 7 (F7), Fort 8 (F8) and Umicore (UM). UM is closest to the pollution source and F4 farthest away. UM and F8 were grouped into one site for final analysis. Band number, colors and PIT tag are three different individual identity markers. Basic body measurements are also given, including body mass on the night of capture (weight in) and body mass measured after the personality test on the following morning (weight out).
Metal gradient exploration scores, 06-12-17.xlsx
Metal pollution gradient STI data
This file contains behavioral measurements collected during simulated territory intrusions (STIs) performed at study sites across a metal pollution gradient in Antwerp, Belgium, in 2017. Moving away from the pollution source, the study sites were Umicore (UM), Fort 8 (F8), Fort 7 (F7), Fort 5 (F5) and Fort 4 (F4). UM and F8 were grouped into one site for the final analysis. Behaviors measured for males during the 3 min STI were: latency to approach (min), approach distance (MinDist, m), time on the decoy (min), and number of calls, songs, dives and attacks on the decoy. Scores from a principal components analysis performed on this data are also included in the file. For females, latency and approach distance were measured, and aggressive behavior was scored (Fem Score) as described in the manuscript.
STI data metal pollution gradient, 06-12-17.xlsx
Metal pollution gradient hissing data
This file contains results from hissing tests performed on female great tits across a metal pollution gradient in Antwerp, Belgium, in 2017. Moving away from the pollution source, the study sites were Umicore (UM), Fort 8 (F8), Fort 7 (F7), Fort 6 (Fort 6/CDE), Fort 5 (F5) and Fort 4 (F4). UM and F8 were grouped into one site for analysis. Hissing behavior is a form of nest defense. Thus, a larger number of hisses indicates more intense nest defense. The ND score (nest defense score) was not used in this paper, but increases with intensity of nest defense. Information on female aggressive and exploration behavior is also contained in this file, where available.
Hissing test data metal pollution gradient, 06-12-17.xlsx