RiverQuestion of the Month

for January 2009

Compiled by Jennifer Robertson, M.Ed.

RiverQuest Education Specialist

 

Question:

This past fall, students from Colfax Upper Elementary School in Springdale spotted a Bald Eagle at Brunot's Island on the Ohio River, as they searched for birds from the decks of the RiverQuest fleet.

Are Bald Eagles nesting along Pittsburgh's rivers?

 

Answer:

Not yet, but there are favorable signs that Bald Eagles may soon be nesting in Allegheny County.

The bald eagle pictured directly above was photographed by Mr. Bob Ochsenhirt from Colfax Upper Elementary School, Allegheny Valley School District.  The picture was taken from the decks of the RiverQuest fleet, as the vessel sailed on the back-channel of Brunot's Island, just upstream from the McKees Rocks Bridge on the Ohio River near downtown.

Bald Eagles (Haliaeetus leucocephalus) are native to North America. Their historic range stretches from Alaska and Canada to northern Mexico. At the time of the Bald Eagle’s designation as our national symbol in 1782, there was a healthy population of the majestic birds. Fast-forward almost 200 years to 1973, and there were less than 500 documented nesting pairs in the continental United States. A number of factors, including habitat destruction, illegal poaching, water quality degradation and a shortage of prey species played a role in the decline of Bald Eagles. But the widespread use of the pesticide DDT was linked to the most dramatic decrease in Bald Eagle numbers. DDT causes eagles and other birds of prey to produce egg shells that are too thin to support the incubating parent’s weight.

The Bald Eagle protection act of 1940 and the Migratory Birds Treaty Act were steps taken to help save our national symbol. The 1972 banning of DDT in the United States, coupled with the Endangered Species Act the following year permitted remaining eagles to begin having successful breeding seasons once again.  The PA Game Commission initiated a reintroduction program in the 1980s, relocating ~90 eaglets from Canada to the commonwealth. That initiative, along with similar programs in neighboring states, led to a dramatic increase in Pennsylvania’s Bald Eagle population in the 1990s and into the new century. Recently, the Bald Eagle was upgraded from endangered to threatened in Pennsylvania.

On the federal level, new protection legislation and reintroduction efforts allowed for the birds to be upgraded from endangered to threatened in the contiguous U.S. in 1995, and eventually to be removed from the federal list of threatened and endangered species in June of 2007.

Currently, the Commonwealth of Pennsylvania sustains approximately 150 nesting pairs of Bald Eagles in 47 of the state’s 67 counties. Their concentrations are the greatest in the southeastern and northwestern corners of the state. Their status in southwestern Pennsylvania has been improving steadily. Several counties surrounding Allegheny County have confirmed nests, and Bald Eagle sightings in Pittsburgh and surrounding areas have been on the rise in recent years.  These sightings, along with thee availability of wild areas for nesting and hunting along the rivers, are favorable indicators that a nesting population of Bald Eagles in the Pittsburgh area could just be a matter of time.

Comment? Question? Bald eagle sightings?

Email  your feedback to us at info@riverquest.org.  Thanks!

 

 

Sources:

  • Cornell Lab of Ornithology (2009). 2nd Pennsylvania breeding bird atlas (2004-08). Online (Available) http://bird.atlasing.org/Atlas/PA/Main?cmd=state Summary&theme=species&edition=current&species=baleag&species=Go, January 2009.
  • Pennsylvania Game Commission (2006). Threatened species: Bald eagle. (Online) Available www.pgc.state.pa.us/pgc/cwp/view.asp?a=458&q=152498, January 2009.
  • Pennsylvania Natural Heritage Program (2008). Bald eagle (Haliaeetus leucocephalus). (Online) Available www.naturalheritage.state.pa.us/factsheets/ Bald%20Eagle.pdf, January 2009. 
  • St. John, Kate (2008). Outside my window: A bird watcher’s view of the world. (Online) Available http://www.wqed.org/birdblog/2008/07/04/bald-eagle-nes/, January 2009.
  • U.S. Fish & Wildlife Service. Bald Eagle fact sheet: Natural history, ecology, and history of recovery (2007). (Online) Available www.fws.gov/midwest/eagle/ recovery/biologue.html, January 2009.

 

Images:

 

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