Posted by: rlukei | 2012/01/19

Eagle Deaths at Norfolk Botanical Garden

Statement prepared by Dr Bryan Watts, Director of The Center for Conservation Biology, with respect to the death of an adult and a juvenile bald eagle at Norfolk Botanical Garden.


Eagle Mortality Norfolk
Botanical Garden

On a global scale, our electrical infrastructure kills millions of
birds annually.  There are three common
ways that birds are killed when interacting with transmission or distribution
lines.  The most common of these is
referred to as pole electrocution.  Birds
perching on power poles are electrocuted when they come in contact with two
conductors and complete a circuit.  To
overcome this problem, power companies have retrofitted power poles in areas
known to have problems to prevent birds from making these contacts.  The second most common cause is referred to
as a mid-line electrocution which occurs when a large bird flies through the
lines and is able to complete a circuit by touching two wires with its
wingtips.  The third form of mortality is
when a bird flies into lines does not complete a circuit but is killed by the
trauma.  Bald eagles are particularly
vulnerable to mortalities related to the electrical infrastructure because they
are large enough to bridge the gap between conductors.

In a recent investigation of 62 eagle mortalities caused by power lines
within the upper Chesapeake Bay, Bryan Watts and Libby Mojica from The Center
for Conservation Biology determined that both line location and context had a
significant influence on the likelihood that they would kill eagles.  Lines that are near water or foraging areas
are crossed regularly and have a greater likelihood of being problem lines.  Lines that are exposed in open areas are much
more likely to kill eagles compared to those that are associated with screening
vegetation.  This is because tall trees
planted near electrical lines serve to shift the flight line of eagles above
the power lines.

In just the past 2 weeks, two eagles have been found dead within the
grounds of Norfolk Botanical Garden that were associated with power lines.  The first was an adult-plumaged female and the
second was a juvenile-plumaged bird.  The
juvenile clearly died by trauma-related mid-line strike, and the adult is suspected
as having also died by trauma-related mid-line strike.  The extent to which these mortalities were
facilitated by interactions with other eagles is not clear.  We have very little information on causes and
rates of eagle mortality but such events are likely much more common than we
currently know.


Dr Watts – Quote: In a recent investigation of 62 eagle moralities caused by power lines
within the upper Chesapeake Bay

What time frame would be the 62 eagle moralities? Weeks, months, years? Thanks in advance. Shoebutton♥
Response – The eagle deaths occured 1985-2007 and included only those that could be directly associated with powerlines

Thanks so much for the reply above!

Thank you so much for this information, tears for the beautiful female and for the juvenile, so heartbreaking, but dad has taken yet another mate so in this we will celebrate. Duane thank you for your response, put very well.

Two years ago I would not have been concerned about the death of an eagle. I was uneducated and ignorant(guess that is the same thing) about importance of our eagles. The eagle cams, CCB and many people like Dr. Watts are doing the research and educating us ignorant people why we should care. By educating us, they are also developing the first line of defense against misguided abuse of our wildlife. They are also taking steps ecologically and legally that will improve wildlife coexisting with us humans. It does take time and I am grateful for the tremendous effort all give to make such changes possible. Thanks

Thank you for all you do in keeping us informed and teaching us so much about wildlife and life in general…..we all need to step back and realize that life is at best a fleeting moment and your sharing your photos and knowledge with us makes that time the best we can ever have. Go Dad and new lady…..make babies!!!!!

Thank you, Dr. Watts, for studying and explaining the cause of these tragedies. Has the power company been alerted to this situation? Perhaps they can do something before we lose another eagle, (or other species).

Thank you, too, for the information. I know that lead is a big problem too. Wish hunters/fishers would get the message. I understand it is more expensive, but it is so important.