The Effect of Polychlorinated Biphenyls on the Song of Two Passerine Species

Abstract

Polychlorinated biphenyls (PCBs) are synthetic chemical pollutants with demonstrated detrimental toxic and developmental effects on humans and wildlife. Laboratory studies suggest that PCBs influence behavior due to their effects on endocrine and neurological systems, yet little is known about the behavioral consequences of sublethal PCB exposure in the field. Additionally, specific PCB congener data (in contrast to total PCB load) is necessary to understand the possible effects of PCBs in living organisms since number and position of chlorine substitution in a PCB molecule dictates the toxicity and chemical fate of individual PCB congeners. We non-lethally investigated total PCB loads, congener specific PCB profiles, and songs of black-capped chickadees (Poecile atricapillus) and song sparrows (Melospiza melodia) along a historical PCB gradient at the Hudson River in New York State. Our results indicate that black-capped chickadees and song sparrows have higher total blood PCBs in regions with higher historic PCB contamination. The two bird species varied substantially in their congener-specific PCB profiles; within sites, song sparrows showed a significantly higher proportion of lower chlorinated PCBs, while black-capped chickadees had higher proportions of highly chlorinated PCBs. In areas of PCB pollution, the species-specific identity signal in black-capped chickadee song varied significantly, while variation in song sparrow trill performance was best predicted by the mono-ortho PCB load. Thus, PCBs may affect song production, an important component of communication in birds. In conclusion, we suggest that the ramifications of changes in song quality for bird populations may extend the toxic effects of environmental PCB pollution.

Latent cognitive effects from low‐level polychlorinated biphenyl exposure in juvenile European starlings (Sturnus vulgaris)

“…Hoogesteijn et al found reduced volumes of the song control nucleus robustus arcopallialis in the brains of juvenile zebra finches after exposing the maternal hens to just 40 μg Aroclor 1248, which for a typical 12‐g finch is equivalent to 3.3 μg Aroclor 1248/g body weight (measured egg concentrations = 0.19 μg/g wet w). A study from the historically PCB‐contaminated region of the Hudson River revealed that black‐capped chickadees ( Poecile atricapillus ) and song sparrows ( Melospiza melodia ) in the affected area had higher blood PCBs and altered song profiles . Possibly most compelling is that the present study extends from research on the same set of dosed starlings tested previously in an autumn migratory experiment, which were found to have impaired migratory orientation ability .…”

Current concepts in neuroendocrine disruption

“…Furthermore, sexually dimorphic behaviors were altered in rats exposed to PCBs (Lilienthal et al, 2013). Adverse effects of PCB exposure on reproductive and thyroid systems as well as singing behavior have been observed in birds (Deleon et al, 2013; Ottinger et al, 2013). Other effects, including impaired cardiac development, which may reflect early impacts on growth factors, have the potential to greatly diminish the fitness of the individual (Carro et al, 2013).…”

Embryonic exposure to environmentally relevant concentrations of a brominated flame retardant reduces the size of song‐control nuclei in a songbird

“…We found that timing of exposure is important, and the in ovo stage appears to be a more sensitive window than the early post-hatch period with respect to the effects on the song-control system from organohalogen contaminant exposure. The present study contributes to the increasing evidence that studying the song-control system and could be a sensitive tool for assessing impacts of environmental contaminants (Gorissen et al, 2005;Iwaniuk et al, 2006;Hoogesteijn et al, 2008;Markman et al, 2008;McKay and Maher, 2012;DeLeon et al, 2013). Effects on song learning and production could also potentially serve as a link between contaminant exposure and effects that are relevant for ecological risk assessment, such as reproductive and population level effects.…”