Azalea at Lake Taylor 6pm Jan 18
January 19, 2012Replacement Female Jan 20, 2012
January 21, 2012Statement 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.
27 Comments
Oh so sad! Thank you for the explanation, I’ve been wondering about this very thing. Another urban hazard.
Is there a way to work around/with the power lines to make these deaths less likely to occur at NBG?
Incidentally Dr. Watts, thanks for the update and explanation.
I hope that the adult female found was not the new mom Norfolk.
I am sorry to see that a juvie was lost too.
Thank you for this statement, Dr. Watts.
Questions – Are the lines checked for bare spots ? Why are they not underground ?
Response – Your question implies that you assume overhead electric wires are coated or covered. They are all bare electric cable, everywhere.
We NBG Bald Eagle fanatics are all wondering if the adult F was the one we had been seeing with “Pa”. I know it’s mating season and hormone levels are pushing to mate, and, it if was the F from pre-2012, he could have another mate now, in order to breed.
I’m hoping the Juvenile wasn’t the beautiful mottled brown/white seen in Mike Inman’s Zenfolio photos – he/she is/was a magnificent specimen. Photos 14, 19, 30
http://mikeinman.zenfolio.com/p59528096/h16DC59D7#h16dc59d7
Thank you Dr. Watts & CCB for sharing this info with us. All of us Eagle/wildlife lovers appreciate all that you do.
Sorry, I meant photos 14, 19, 20
The photographers say the NBG male’s new mate – Mom2 – had a notch in her wing. Why cant those doing the necropsy check for that so we know for sure?
zoomer isnt posting that he is seeing nesting activity – and other eagle cams are. It seems highly unlikely our pair would seek a NEW nest site after apparantly laying claim to zoomers nest.
* is there a way to make these anti-spam letters more CLEAR? I cant make them out
If this is a common cause, what is the possibility of putting those lines at NBG underground ? It my mean time and expense but some precautions need to be considered. If for anything to protect the eagles especially dad and new mate as well as future
Maybe Morlan Nelson can offer some advice. He is a great ambassador for the eagles amd other birds of prey. He has great ideas about high center poles as well as nest platforms and even dropping the side wires to avoid electrocution. Check out this website:
http://www.avmv20.dsl.pipex.com/Articles/One_More_Hero.htm
Maybe the Garden should have spent some of its Chase money on burying electric lines … and less money on an eagle statue.
Thank you Dr.Watts and CCB for that report about the 2 beautiful eagles that expired at the gardens.We appreciate being kept inform.Man’s invention certainly interferes with Nature.
Could the power company put ‘ribbons’ or reflectors of some kind on the lines out in the open so they are more readily seen by a flying bird??
Response – The juvenile flew into the powerlines at 6:30 at night. Neither ribbons or reflectors would have been visible.
The Eagle statue was donated (donated means given or free of charge) by Turner Sculptors and the Eagle memorial was built from funds collected by NBG after the females death. The Chase monies is being used for educational programs and such if I’m not mistaken. I have been frequenting NBG since early 2008 and this is the first incident of wildlife being killed by powerlines at NBG that I know of. Do some homework Ben before laying blame on anyone or anything please. Yes, it’s upsetting an Eagle was killed by the powerlines but accidents do happen…this one happened to occur at NBG. Most of the powerlines run through the trees and plantings and for the most part the Eagles fly over these areas.
CJ – do what I do and keep hitting the top blue button until you see one you can decipher and enter.
The F did have a notch in on wing and she also had a specific feather pattern on her left eye, if you go back and look at color photos of her… it’s like something happened to her feathers and not all came back.
Thanks to Dr Watts for his statement and to Reese for posting it! It’s sad to lose two eagles.
In light of Duane’s helpful explanations, perhaps the question should be asked this way. There have been two reported bald eagle deaths at the Garden in the past two weeks. What steps is NGB taking to prevent this from happening again and again?
Response – In the nine years that the eagles have been at NBG this is the first time anything like this has happened to eagles or any other birds. Of course, we would like to know as much as possible about why they happened, but as of now both incidents look like just plain accidents that could have happened anywhere powerlines are present. We will likely never know all the answers, such as why was the juvie flying at 6:30 at night when it was pitch black dark? Was the adult being chased and not looking where it was flying? Some accidents are not preventable. Perhaps changes can be made at NBG, but it may take time to determine what to change and how.
Thank-you…..Duane.
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.