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Wednesday, December 23, 2015

More about electrocution

Worldwide electrocution is a huge problem for large birds, including many eagles and vultures. Many of the species affected by electrocution (like the Egyptian vulture) are also endangered, and electrocution contributes to their poor conservation status.  Click here to access a paper on electrocution of Egyptian vultures in East Africa by Ivaylo Angelov and others.  If you Google the words "bird electrocution power lines" you will be able to see loads of images of many species that have been electrocuted, mostly large species and many predatory birds



Oman is recognized as a global stronghold for Egyptian vulture because of its seemingly stable breeding population, and as a destination for many migrants from farther north.  It is also an important winter destination for migrating eagles, like the endangered Steppe Eagle (which is on the 100 Baiza note) and Eastern Imperial Eagle.  Oman was thought to be relatively safe for Egyptian vultures, and other species, although the possibility that birds were being electrocuted was always there.  Sadly, this incident shows that electrocutions occur, we just don't know at what rate.
Juvenile Egyptian vulture perched on a dangerous power line in Oman. (Photo: A. Kovac)


While the news of this bird's death is sad, and the prospect that more birds are electrocuted is worrying, there is a positive side.

1) Oman is a developing country and is only now installing much of its power transmission network, a process that will grow as the human population grows and human activities are started up in new areas.  This means that using pylon designs that reduce electrocution during this development phase could help avoid future electrocution at almost no additional cost.  Much has been done in North America http://www.aplic.org/, Europe and Africa to design such safe pylons.

Juvenile golden eagle electrocuted on a power line in North America (Photo: USFWS)
2) The distribution in Oman of the large birds that are most vulnerable to electrocution is somewhat predictable.  Many of the migrating raptors are also scavengers and concentrate near rubbish dumps and many of the resident raptors are territorial and use particular habitats.  This means that "sensitivity maps" can be drawn that identify areas where risk is particularly high, and these areas can then be the focus of efforts to reduce that risk.  In doing this the biggest conservation benefit will be realized sooner and with the least effort and cost.

Wintering Steppe Eagles on a dangerous pylon near a rubbish dump in Oman (Photo: A. Kovac)
3) In some cases the most immediate solution is to change the pylons that are most dangerous.  This, of course, costs money.  Because of this problem bird biologists have long worked with transmission line engineers to design cost-effective solutions or retro-fitting.  Indeed, in the long run these modifications could save money by reducing the number of times engineers have to visit sites of electrocution.  Reducing electrocutions would also have the advantage of reducing power outages to customers.


If you'd like to read more about this problem, click on the links below.

https://www.ewt.org.za/species%20factsheets/bop/Electrocution.pdf
http://www.ub.edu/aligaperdiguera/EEAPcat/pdf/Tinto_et_al_2010.pdf
https://sora.unm.edu/sites/default/files/journals/jfo/v062n02/p0181-p0190.pdf
http://wildlifepreserves.org/files/pdfs/Bird%20Collisions.pdf
http://www.murcianatural.carm.es/europa/life00214/pdf/DISCOLIFE_/LIFE_tendidos_Murcia2/Albert_Tinto/Ma%F1osa2001.pdf

Monday, December 21, 2015

Sad News

It is with great regret that I report that the Egyptian vulture we have been tracking since January 2015 has died.  The Environment Society of Oman (ESO) has posted something on Facebook (https://www.facebook.com/EnvironmentSocietyOfOman/?fref=ts).  The last transmission we had from this bird was in the afternoon of 13 December from a location just north of the Sifa Resort.  Sensors on board the transmitter showed it to be working normally, but the transmissions ended abruptly.  Below is a map of the locations in the week before the end of transmissions.

Vulture locations in the week before its death.
Last two locations
We waited for another transmission cycle to pass before worrying because other things can affect transmissions, like the amount of sunlight or whether the bird is in view of a satellite.  On 19 January Dr. Glyn Barret went in search of the bird, using the coordinates of its last location.  He found it dead from apparent electrocution under power lines and a transformer.  The transmitter was apparently fried.  See below.

Dead satellite tagged Egyptian vulture below power lines near Sifa. (Photo G. Barrett)
Last location.  One can see the shadow of the pylons in the picture above.

Dead vulture.  Transmitter can be clearly seen in the middle of the picture.(Photo G. Barrett)
The dead vulture during happier days (Photo W. AlFazari).
Worldwide electrocution is a huge problem for large birds, including many eagles and vultures.  Many of the species affected by electrocution (like the Egyptian vulture) are also endangered, and electrocution contributes to their poor conservation status.  Click here to access a paper on electrocution of Egyptian vultures in East Africa by Ivaylo Angelov and others.

Oman is recognized as a global stronghold for Egyptian vulture because of its seemingly stable breeding population, and as a destination for many migrants from farther north.  It is also an important winter destination for migrating eagles, like the endangered Steppe Eagle (which is on the 100 Baiza note) and Eastern Imperial Eagle.  Oman was thought to be relatively safe for Egyptian vultures, and other species, although the possibility that birds were being electrocuted was always there.  Sadly, this incident shows that electrocutions occur, we just don't know at what rate.  Indeed, it may have been that the other vulture we tracked, which disappeared in March, was also electrocuted.

In the coming days I'll post more information on the issue of electrocution and birds, so hopefully this sad event will have some positive effect.

Thursday, December 10, 2015

Early December 2015

The tracked Egyptian vulture has settled into the area where it has spent most of its time since it was captured 11 months ago.  Early in the month it was located mostly inland from Sifa, then during 4-5 December it was on the coast south of Quriyat, and roosting on a power pylon SW of the town. In recent days it has moved back up to range in villages along the Muscat to Quriyat road (الطريف Al Traiff
الفياض Al Fiadh, حيفظ Heifdh) and made quick journey to the area around Yiti.  Although back north of the Hajar Mountains, it seems not to have visited the rubbish dump at Al Multaqua in the last two weeks.

Movements of a sub-adult Egyptian vulture during early December 2015.