A day in the life of a vulture

This is an interesting snapshot of what our satellite tracked vulture does in this single day.  Early this morning (28 April) it moved from a location in the Wadi Sareen Reserve, by noon it was back in the area north of Ibra, and made a single excursion out to a storage dam to the north, and by evening appeared to be roosting in a location north of Ibra where it has spent much time over the past weeks (See earlier blog posts).  For much of the past month or so this bird has moved mostly within a 10 km x 10 km area just north of Ibra.

Movements of an Egyptian vulture during a single day, 28 April 2016. (Click on the image to enlarge it.  Time stamps are GMT.  Add 3 hrs for local time)

Early April 2016

At the beginning of the month our tracked vulture was in Quriyat, but it soon moved south over the mountains, and has been staying in a relatively confined area north of Ibra.  It seems the bird has been visiting the Ibra landfill site, but also areas around the ring road being constructed around Ibra.

Movements of Egyptian vulture during early April 2016.

Close up view of movements of Egyptian vulture in the area north of Ibra.

Also, there is a new paper available on vulture use of the Al Multaqua Landfill site.  The landfill is perhaps the best place to see vultures if you are near Muscat.  You can download the paper here https://drive.google.com/open?id=0BzhIfKS1gn5cQjVOeF9TLUt4aFU

End of March 2016

At the beginning of the past two weeks 80 was spending most of its time at the Tahwa Landfill site, and apparently roosting in the mountains (Jebel Qahwan) to the east.  On 23 March it flew west toward Ibra, then south near Sinaw.  It is remarkable how many of the sites this bird appears to be visiting were visited by the bird we tracked in 2015 (Look back at earlier blogs: November 2015).  On 25 March it flew north and spent a short period in the Wadi Sareen Protected Area.  During the past week it has been staying mostly very close to the rubbish dump at Quriyat, with some trips to, what appears from satellite images, a local dump site at Hayl al Ghaf.  Again, this is a site that was visited by other of our tracked vultures (See blog post from Mid May 2015).  Today it has made its way back over the mountains to a location north of Ibra, near where we last heard a signal from a bird we tracked in 2015 (See blog post for 19 February 2015).

Below is a map of the bird's movements in the last week and a map of the bird's movements since it was fitted with a transmitter in mid January 2016.

Movement of Egyptian vulture 24 March-1April

Movement of Egyptian vulture January through March 2016.

Although we have limited data, it is apparent that there are hotspots for Egyptian vultures in Oman, and these include small and large waste disposal sites, and roosting sites in the mountains.  The Egyptian vultures that we tracked have stuck to lower elevations, and that may be because that is where people are and their rubbish.  High voltage electricity pylons are also favoured as roost sites, especially during daylight hours.  Mapping such hotspots would be a useful step in understanding vulture ecology in Oman and promoting conservation.  We know that some vultures are electrocuted, some raptors are shot, and some die from ingesting poisons and contaminated food.  Also, development, such as windfarms and the associated transmission infrastructure, are a threat to migratory soaring birds.  A "sensitivity map" of locations likely important to vultures would enable government, private companies, and conservation organizations to target areas for caution and conservation effort.  Sensitivity mapping is being used by Birdlife to highlight areas potentially important to migrating soaring birds http://migratorysoaringbirds.undp.birdlife.org/en/sensitivity-map and has been used to identify areas where conflicts may exist between golden eagles and windfarms http://rwww.rspb.org.uk/Images/bright_langston_bullman_others_tcm9-192434.pdf

Early March 2016

On 1 March, 80 was visiting a rubbish dump just east of Bidiyah, but soon flew back to area around the Tahwa Landfill, where it has spent much of the past month.

Movements of juvenile Egyptian vulture (80) during first half of March 2016.  Click on the image to open it up larger in a new tab.

The map below shows the movements of 80 during a single 24 hour period.  The time stamps are in GMT, so one can see that the vulture is spending the day at the Tahwa Landfill, and its nights roosting in the steep sided wadi to the east.

Movements of juvenile Egyptian vulture during a single 24-hour period.

End of February 2016

Some good news and some not so good news... First the good news.

80 has spent the last two weeks south east of where it was caught. From 16-23 Feb it was mostly in the mountains near the village of Wadd.  During 23-29 February it mostly visited the Tahwa Landfill site, which is the main waste disposal site for Sur.  While there it spend a good deal of its time perched on the pylons of the high voltage power line nearby, but also spent time in the northern Jebel Qahwan (Does anyone have a map of the new MECA protected area in Jebel Qahwan?  If so, can you send it to me?   Its a great place to see resident Egyptian vultures and there are some unknown number of breeding pairs in the mountains there.).  On the 29th it made a leap to the west, moving between the mountains and the Wahiba Sands near the towns of Bidya and Al Qabil.  Its last locations in February were on some power lines just south of the main road, near the Bidya rubbish dump.

Movements of juvenile Egyptian vulture during 16-29 February 2016.

Movements of Egyptian vulture between pylons (linear array of points left of centre), Tahwa Landfill (cluster near the centre of the map, and Jebel Qahwan (duster to the right).

Movements of juvenile Egyptian vultures on 29 February 2016.

The bad news is that 93, the other bird we were tracking, has died.  It flew out from the pylon on which it roosted in Al Amerat on the 16th, and two hours later we were receiving the signal from a non-moving transmitter.  When we recovered the bird there was no evidence of what was the cause of death.  It was not very near to any powerlines, and there was no obvious evidence that it had been shot.   Sadly, we were unable to collect it as soon as it died, and in the warm air of Oman, the body decomposed quickly.  Thus, clues as to why it died may have been lost.  While it is tempting to speculate that some human-related factor was involved and we know there are many human related threats to vultures, it is true that juvenile birds of all species, including Egyptian vultures have high rates of natural mortality.  While we know of no studies on this species, similarly sized raptors can have natural first year mortality of 70% or more.  Still, we are very sorry to lose 93. Here is a link to information on tracking of vultures from Bulgaria, which sadly also shows that mortality seems to be very high for this species http://www.lifeneophron.eu/en/news-view/371.html 

Early February 2016

The birds we fitted with transmitters have been moving about a bit.  Like the birds we tracked last year, they have not visited the Al Multaqaa landfill consistently since we trapped them.  I have talked to Dick Forsman (author of a umber of books on raptor identification) and he tells me that based on the timing of the moult we observed in the birds we captured, he would think they are probably from southern parts of the species distribution... perhaps Oman.

Below are some maps of the movements of the two vultures we have been tracking (Click on the images and they should open up larger in a separate window.  Currently we identify them by their transmitter numbers (80 and 93), but perhaps we should find names for them. In the first two weeks of February, 80  has been mostly east of Sur (near the village of Wadd) and 93 was on 1 February about 6 km east of Sifa, and since then has been mostly in the Al Amerat area (roosting on power lines near the Oman Oil petrol station south of the road from Boushar).

For the last six months or so we have been collaborating with the Vulture Conservation Foundation. They have featured the work in Oman on their web site http://www.4vultures.org/news/.  Have a look at that and all the other things they are doing for vultures.

Movements of "80" during the first two weeks of February 2016.

Movements of "93" during the first two weeks of February 2016.

Have you seen a ringed bird? Let us know.

Before radio tracking of birds was possible, scientists marked birds with uniquely numbered rings to provide information on the movements of birds, how long they lived and to estimate likely population size and detect population trends.

While radio tracking has some advantages, it has not made marking birds by other means obsolete, and ringing remains a basic tool used by scientists, the data from which can be combined with information from radio tags to better understand bird ecology.  The data from both are similar:  the bird is "marked" with a radio tag or ring at some known location and time, and then "recaptured or recovered" at some later known location and time.  The main difference is that recapture of radio tagged birds is done remotely (and usually more frequently) via the radio signal, and the ringed bird is usually physically caught or found dead.

Egyptian vulture marked with uniquely numbered metal and Darvic rings (Photo: M. McGrady)

Some of the main advantages of ringing include its low cost and that it can harness the efforts of amateurs, citizen scientists and the public to collect useful information.  In recent years, the availability of high quality optics and affordable high resolution digital cameras has made the accurate identification of birds possible for anyone by examining closely pictures of birds with rings or wing tags and then getting in contact with those who fitted the rings/tags.

Wing-tagged eagle in Kuwait.

Because Oman is a winter destination for many birds from farther north, and a stronghold for many species of conservation interest, Oman is a good place to look for marked birds (or at least keep them in mind when you are viewing your photos after a day in the field.).There have been a number of cases of marked birds turning up in Oman, being spotted by birdwatchers or photographers, and identified from their marks, including the steppe eagle below, an eastern imperial eagle from Kazakhstan some years ago, and an eastern imperial eagle in 2015.

Colour-ringed Steppe eagle near Salalah (Photo: A.Kovac)

Close up of colour ring from digital photograph (Photo: A. Kovac)

So, if you do spot a bird (of any species) in the wild with a ring or find one dead (or you know someone who does), please report it to us (just make a comment on this blog).  If it is one we have marked we will give you information on it; if it is not, then we will work to find out who did ring the bird, and pass that information along.  Such information is highly valuable to us as we try to understand these birds and conserve them.

Colour-ringed Egyptian vulture on a carcass in France. (Photo: C. Ponchon)