Monday, March 17, 2014

Osprey: A Tale of Perseverance

In all its majesty, it soars over the marsh. Suddenly its bright yellow eyes notice lunch swimming below, an unlucky fish. Within a split second it folds its wings back and prepares for a dive. A few seconds more and splash. The Osprey briefly disappears into the water only to emerge with a 12 inch fish locked into its specialized talons. That’s right; the Osprey (Pandion haliaetus) is the best fisherman you will ever meet, averaging a mere 12 minutes per hunt (all about birds). Although this fascinating bird of prey seems to be “king of the air”, it has undergone many adversities in the past 60 years.
"Osprey at sandy beach" taken by Scott Kruitbosch
You see, there used to be this pesticide, DDT, which was commonly used. However, DDT (and other contaminants) was proven to lower productivity of the Osprey and it weakened their shells, as you would expect this greatly decreased the Osprey’s population. In fact, a study by K.E. Clark et al estimated that the pre-DDT population in New Jersey was between 350-400 pairs and in 1975 it plummeted to only 66 pairs (Clark)! I’m getting ahead of myself though. Before I tell you about the hardships encountered by the Osprey, you must first have a respect for them. I don’t know to what extents you would go to for a chance at breeding, but the Osprey seems to have no limits. Over the winter months (non-breeding), the Osprey is found typically in Central and South America and as far north as the southeastern U.S. However, come spring time these birds migrate north, inhabiting most of Canada and the east coast of the U.S. for the summer. They travel thousands of miles twice a year for a chance at breeding and to raise their young in hospitable habitats. For an adult Osprey nearing old age, (15-20 years) it will have traveled up to 160,000 miles in its lifetime just to breed (all about birds)! You can see how egg shell thinning by DDT is such a big deal! Now you understand the level of investment the Osprey puts into their offspring. 
In Pamela C. Toschik’s article, “Effects of Contaminant Exposure on Reproductive Success of Osprey (Pandion haliaetus) Nesting in Delaware River and Bay, USA” eggs were collected from 39 nests to look for various contaminants. All of the study’s together had at least one young Osprey fledge in 66-75% of the nests. They concluded that “contaminant concentrations were predictive of hatching success” and thus it is still a major stress for the productivity of Osprey (Toschik). Since contaminations are still such a major concern, researchers like Robert A. Grover are using the Osprey as an “sentinel species”, a species to get a broad idea of what the contaminants can do to other species. In an article by Grover he states that the Osprey is a perfect organism to study because contaminates effect the birds immune system, reproduction, behavior, and anatomically through bird defects. Thus, it is a good model species to get a better understanding of broad effects of chemical contaminants on Avian (bird) species. The study did show that populations have recovered nearly everywhere (even in some of the most polluted era) from the initial DDT destruction (Grove).
            Now that you have an understanding for the level of perseverance displayed by the Osprey you cannot help but have respect for these birds. Although they have undergone many hardships, they have rebounded. Although contamination is still a major concern for the Osprey and many animals, we now know how important it is to limit the contaminants and keep our waters clean.

To see great footage of the greatest fishers of North America click on the video below.

All About Birds. The Cornell Lab of Ornithology, N.D. Web. 16 March 2014.
BBC. “Ospreys Catching Fish-The Animal’s Guide to Britain, Episode 1 Preview-BBC Two”. Video. YouTube. YouTube, 13 April 2011. Web. 16 March 2014.
Clark, K.E., et al. “Changes in Contaminant Levels in New Jersey Osprey Eggs and Prey, 1989 to 1998” Environmental Contamination and Toxicology 40 (2001): 277-284. Web.
Grove, Robert A., et al. “Osprey: Worldwide Sentinel Species for Assessing and Monitoring Environmental Contamination in Rivers, Lakes, Reservoirs, and Estuaries.” Journal of Toxicology and Environmental Health 12b (2009): 25-44. Web.
Kruitbosch, Scott. “Osprey at sandy beach.” Photograph. Long Island Sound Study. Osprey Makes Comeback, n.d. Web. 16 March 2014.

Toschik, Pamela C., et al. “Effects of Contaminant Exposure on Reproductive Success of Osprey (Pandion haliaetus) Nesting in Delaware River and Bay, USA.” Environmental Toxicology and Chemsitry 24.3 (2005): 29. Web.

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