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The sensitive nature of avian biochemistry and why it is an essential tool in ERAs.

I talk a lot about birds, so I figured why not back up that passion with more science. 

    Lately, I have been reading on the versatility birds offer in regards to environmental risk assessment. Aside form their sensitive biology, birds provide migratory behaviors, breeding site fidelity, not to mention countless developmental factors like eggshell thickness, incubation periods, parental investment, etc. (Scheuhammer et al., 1987). There are many measurable biological phenomena that birds display, and they each are sensitive, to a degree, and subject to alteration due to heavy metals, PCBs, and other pollutants (Zhang et al., 2011).

    Something that I personally wanted to explore was the ability to test materials in bird feathers, showing what has possibly entered the trophic chain via ingestion of other species or incidental ingestion. This non destructive method of sampling could allow for more rigorous and larger sampling without ecological detriment (Zhang et al., 2011). With further study, different feathers, be it down feathers that show in early development, or fully developed flight feathers, different concentrations and readings can be deciphered, leading to effective ERA baselines.

    Another positive with this kind of sampling is the storage ability. We can use things like feathers, eggshells, and other externals to compare spatial-temporal trends and preserve those samples for comparisons to come (Zhang et al., 2011). With efforts to improve, restore, and clean our world proving to be mandatory for our well-being, not to mention everything else we share the planet with, avian species possess non-disruptive points of sampling that can aid in restoration metrics.

    With eggshells, we are able to see local levels, with breeding parents feeding and in the area during development of zygotic material (Burger et al., 2002). This helps combat a possible issue of migration and the inability to pinpoint where a proportion of internal contamination came from. While nestlings provide valuable data into the nesting season, some species have multiple broods during a season, allowing for egg shell data collection throughout the duration of a Spring-Summer breeding period.

    Birds are very sensitive to heavy metals, and likely die when subject to regular exposure (Furness et al., 1993). From my experience, that is a common marker for action, and I can't help but ask: why not sooner? If we can trace elements in the hairs of humans, and with many common biological traits that define the animal kingdom, maybe similar methods for testing could be explored in different animal species. With a high sensitivity to ecosystem alteration and pollution, birds and their development could be further pushed as environmental bioindicators.

A. M.Scheuhammer. The chronic toxicity of aluminium, cadmium, mercury and lead in birds: a review.         Environ. Pollut., 46: 263-295 (1987)

J.Burger Food chain differences affect heavy metals in bird eggs in Barnegat Bay, New Jersey.                        Environmental Research Section A, 90: 33-39 (2002)

R. W. Furness and J. J. D. Greenwood. Birds as monitors of environmental change. Chapman and Hall             press, London, UK (1993)

W. W. Zhang and J. Z. Ma. Waterbirds as Bioindicators of Wetland Heavy Metal Pollution. Procedia Environmental Sciences,  vol. 10, 2769–2774 (2011)

Comments

  1. Liz Jurado April 27, 2021 at 4:15 PM

    Hi Jake! I never would have considered bird feathers a potential bio-indicator for population and ecosystem health. You mentioned that this method would be non-destructive compared to some of the other bio-indicator currently used. This makes me wonder about the sampling method you might use if feathers turn out to be a good marker. Would they be more opportunistic? Would this introduce any bias into sampling?

    I agree with your "why not sooner" mentality. It seems our attention is often only grasped when the impacts of pollution are severe. I believe that preventative surveillance is the key to effective environmental management!

    ReplyDelete

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