Below is a map which shows the last 1000 locations of Egyptian vulture 16095. We are collecting data at a high rate (maximum 1 location/sec depending on solar power constraints). The map shows that this bird spent earlier parts of the morning at the Al Multaqa landfill. It then started soaring over the landfill and gained altitude, then flew in a straight line about 2 km to the south, circled once more to gain a bit more altitude, then perched.
Analyses of such data can allow us to understand the flight behaviour of vultures in relation to weather information, topography and location of food resources. Such understanding can help conserve vultures by enabling us, for example, to better understand the risk of collision at wind farm sites, and adjust turbine placement accordingly.
Movements of an adult Egyptian vulture during the morning of 7 July 2019
In January 2018, when we caught the vultures we are currently tracking, we assumed that most of them were from migratory populations and that they would leave Oman during the breeding season. However, to our surprise NONE of the birds we tagged were migratory, and that suggested instead that the breeding population in Oman is much larger than had been estimated (100 pairs, Jennings 2010), especially given the large increase we had recorded on Masirah (Angelov et al 2013)
In February-March of this year, a multi-national team (Ivaylo Angelov-Bulgaria; Clémentine Bougain-France; Michael Schulze-Germany) spent three weeks in Oman trying to determine whether the vultures we were following were indeed breeding, and to find other breeding pairs. To do this they used tracking data to identify the territories of tagged birds, which they visited to confirm occupancy. Then, using that as a framework, searched for signs (faeces at perch and nest sites, and attendant birds) of territorial pairs in the vicinity. This was not always easy work because much of the area is in difficult terrain with few roads, and the nests are sometimes not in places where they can be easily observed.
Searching for signs of territorial Egyptian vultures. Photo by the EV Team.
Nonetheless, the team were able to confirm apparent breeding by most of the tracked birds, with some birds apparently starting to incubate eggs by the first week in March. They were also able to find over 80 apparent breeding territories of Egyptian vulture within about 40 km of the main Muscat municipal landfill at Al Multaquaa, and they estimated there might be around 200 pairs in total in that area.
An Egyptian vulture inspecting a possible nest site, March 2019. Photo by the EV team
So, although it has been almost two months since our last positing, it is not the case that nothing has been happening... For their part Egyptian vultures in Oman have started breeding. Once they lay eggs, they will need to incubate them for about 42 days, then the nestlings will remain in the nest for about 70-90 days (so an egg laid on 10 March would produce a fledgling in July). We will continue to track vultures fitted with tags (below is an example of the movements of a vulture during March, showing that it has a territory located near Quriyat, but that it makes regular visits to the rubbish dump at Ibra). We are also analysing more closely the results of the Feb-Mar breeding survey, and aim to publish that in the coming months.
Movements of a territorial Egyptian vulture during March 2019.
The team saw many more interesting things during their surveys; in the coming days we will try to post more information, so come back to the blog or follow us via email.
This from Stoyan Nikolov from Bulgarian Society for Protection of Birds:
In January 2019, a joint expedition of BSPB, RSPB, BirdLife Africa, EWNHS, SCF, NCF and APLORI, under the support of the local experts and authorities, went to Ethiopia with three main objectives:
(1) monitor the numbers of Egyptian vultures in the wintering congregation site in Afar and small part of Oromia region;
(2) collect evidence on the major threats (poisoning, electrocution/collision, and direct persecution) which to inform adequate conservation measures;
(3) deploy transmitters on Egyptian vultures in their wintering grounds.
(1) 1,644 Egyptian vultures were counted to roost in the studied area (1,019 adults/subadults, 644 immatures/juveniles, and 44 birds with unidentified age). This is the highest number recorded so far, compared to previous surveys (2009, 2010 and 2013);
(2) Electrocution and collision with power lines was evidenced to cause significant mortality. We inspected over 180 km of dangerous power lines (medium and low voltage) for electrocution and collision victims. We found a total of 42 carcasses of birds, including 6 Egyptian Vultures and 9 other vultures. Of these carcasses, 22 were victims of electrocution and 15 were victims of collisions with the power line. Most of the victims were concentrated along killer power lines in the areas of Metehara (grassland with high abundance and easily accessible food for scavengers) and Logia (along two rubbish dumps with high abundance of scavengers). Further steps for mitigation of this problem will be done in synergy with MSB II project.
Based on the information collected from the authorities and local stakeholders, non-intentional or intentional poisoning (including with veterinary medical products toxic for vultures) does not seem to be a systematic serious threat for the Egyptian and other vultures in the studied area, neither is direct persecution. However, further investigation will be needed especially re poisoning as an adult individual was found at a rubbish dump and the autopsy of the bird suggests intoxication with heavy metals (final analyses yet to be completed).
(3) Seven Egyptian vultures (2 adults + 5 immatures) were trapped and tagged with GPS-GSM transmitters in the rubbish dumps in Metehara and Logya. You can follow their daily movements via our website. http://www.lifeneophron.eu/#transmitters
The transmitters we have used on some of the Egyptian vultures that we have been tracking since January 2018 can, when light conditions allow, collect location data every second. This means that very detailed tracks of the birds' movements can be mapped. When analysed closely along with information on weather, terrain and habitat, we can start to understand more about vulture flight. This can be important, for example, in understanding the likely risk of vultures colliding with wind turbines, and making decisions about turbine placement and size.
Ivaylo has been taking an initial look at those data. Below is a short story about a 53 km flight by an Egyptian vulture (171328) between its territory near Quriyat and the rubbish dump at Ibra.
On 9.03.2018 at 6:59:35, 171328 took off on a long foraging flight to the rubbish dump near Ibra – 47 km straight-line distance to the southwest. This bird regularly forages at the dump; this was one of 90 such flights that were made in 2018, and one of the 9 this bird made in March. During 2018 this bird also made 49 flights to the main landfill of Muscat at Al Multaquaa, 47 km to the west.
The 53 km track of an Egyptian vulture from its territory near Quriyat to the rubbish dump at Ibra. Yellow pins indicate thermal soaring (Viewed from the NE).
Thanks to the south-facing slopes, the initial third of the route (25 min) was transited in almost level gliding flight, with only two quite brief instances of thermal soaring.
At 7:25 the bird flew over the village of Tool (270 m asl), and started ascending in order to cross the mountain ridge south of it (1070 m asl). To transverse the next 5.5 km and the rising terrain (from 426 to 1662 m asl), the vulture used, during a period of 19:39 minutes, seven consecutive uplifting thermals. During the time spent in gliding flight between the thermals, the vulture lost only 58 m in elevation.
View of flight from the west, showing the use of seven thermals to gain altitude and cross the rising mountains (viewed from the east).
Upon reaching the peak of the central ridge, the vulture flew into and utilised the highest thermal of the flight, which it used for 4:12 min to gain an additional 589 m in elevation, reaching 1662 m asl. While using the thermal the vulture also encountered a strong headwind, which pushed it back in the direction of Quriyat.
Use of a thermal at the ridge of the Eastern Hajar Mountains (viewed from the east).
After covering another 11 km, the vulture entered two, spatially close, consecutive thermals, in which it spent 5:08 min and gained 507 m of altitude (Map below).
The last (№15) thermal soaring occurred 6 km north of the Ibra dump site, over flat terrain above a wadi. The vulture spent 2:08 min in that thermal, and gained 314 m of elevation. From the top of the thermal it descended to the dump site, arriving at 08:30.
The final (15th) thermal flight by the Egyptian vulture before descending to the rubbish dump at Ibra (viewed from the east).
A juvenile Egyptian vulture fitted with a solar-powered satellite transmitter in 2017.
Analysis of data from tracked juvenile Egyptian vultures in Djibouti and Oman suggests that, even when food is plentiful and concentrated in a single place, they will forage over large areas, thereby keeping abreast of the current availability of food. This behaviour would of course be advantageous because information on food availability is a hedge against the ephemeral food on which vultures typically rely (Download the paper by clicking on the link below). Adults may be doing the same thing, albeit affected by breeding/territoriality. But that is another paper, which may arise from data we are collecting in Oman.
It's been almost a month and a half since the last blog. Part of the reason for this is that the vultures have mostly been doing what they have been doing since their capture (No news is good news!). Most have moved around rather restricted areas...most of the time. These areas are most likely their territories, though the vultures have not yet started nesting.
Obviously, territories are needed for breeding, and require a good nesting site. For Egyptian vultures a good nesting site is a hole or crevice in a cliff that provides shade for most or all of the day. In much of Oman, especially the Hajar Mountains, there is an abundance of good nesting sites, and therefore many potential territories. Although a nesting site is important, so is access to sufficient food for survival, and to fuel any breeding effort.
Vultures are adapted to take advantage of food that is normally relatively sparse and widely distributed, and will forage over huge areas. In modern times, as humans have become more settled, rubbish dumps have sprung up around villages, towns and cities, and these are places where vultures can regularly find food; the foraging behaviour of vultures reflects the spatial pattern of food availability.
As a result of the desire to hold a territory and have a nest site in order to breed, and the need to be well-fed to survive and breed successfully, some of the vultures have become 'commuters' between their territories and the rubbish dumps at which they feed. In the example below, the locations are from a vulture with a tag ID of 171328, and have been collected during 31 October - 12 December 2018. This bird spends most of its time on what appears to be a territory just south of Quriyat, but makes regular trips to the Al Hamar rubbish dump, just north of Ibra and about 65 km away to the SW, and the occasional trip to the Muscat municipal landfill near Al Hajar (about 50 km away to the WNW).
Presumably, this bird would have made fewer trips to Ibra, when the Quriyat rubbish dump was in operation, but it has been closed for some time now. The closure of Quriyat may not have had any measurable negative effect on 171328 or other vultures with territories nearby because vultures are well-adapted to cover even very large distances to find food.
During the last month it seems that this bird also spent a good amount of time in Wadi Sareen Reserve. There it would have found plenty of shade, and was willing to leave its territory during this, the non-breeding season, when it may not be so important to defend the territory from intruders.
Movements of an adult Egyptian vulture, 171328 during 31 October-12 December 2018.
In January 2018 we fitted satellite transmitters to 13 Egyptian vultures (12 adults and 1 juvenile) at the Muscat municipal rubbish dump at Al Multaquaa. This blog has given occasional updates on the movements of those birds (and that two may have died). Back in January, we thought that Oman was likely an important destination for vultures migrating from farther north. However, because none of the birds we fitted with transmitters actually migrated, we now think that the large number of vultures at Al Multaquaa in winter are actually resident birds, indicating that Oman's vulture population is probably much larger than estimated. See https://egyptianvultureoman.blogspot.com/2018/10/summer-2018-to-october.html
As mentioned, none of the birds we tracked migrated. All except one settled into home ranges in NE Oman, roughly between Ibra, Samail, Muscat and Sur. However, one bird, 171318, moved up and down the north Oman coast during Jan-April, then hopped across the Straits of Hormuz, and settled on Qeshm Island and the adjoining mainland. It has been there ever since. You can look back at blog posts about its movements https://egyptianvultureoman.blogspot.com/2018/04/a-little-migration.html
John Burnside of Sustainable Houbara Management and University of East Anglia has kindly animated the movements of 171318 @SustainHoubara sustainablehoubaramanagement.org (Have a look what they are doing, and the movements of the Houbara bustards that they have tracked.).
It's fascinating that this bird travelled up and down the coast, covering about 19,000 km before crossing to Iran. In total since January, 171318 has covered almost about 30,000 km! (Double click on the image below or click on the full-screen option in bottom right of image to show in full screen.)
As you may remember, we fitted 12 adult Egyptian vultures with GPS telemetry back in January 2018, thinking that at least some of them would be from migratory populations farther north. It turned out that we were wrong. All the birds stayed in Oman, except one, which just hopped across to Iran. Below is a map of locations over the summer of 11 of the birds we have tracked, each bird has a different colour. You won't be able to make out the locations of some of the birds because their locations will be buried under the others... we have tens of thousands of locations all together. Despite that, the map tells the main story - Oman, especially the eastern Hajars, appears to be a real stronghold for resident vultures. This is real news because in almost all other locations in their huge global range (Iberia to Central Asia, south to India, Arabia and sub-Saharan Africa right across to West Africa) Egyptian vultures are declining and under severe pressure.
We, along with co-authors from the Environment Society of Oman and be'ah, the national waste management company, will be presenting these and other results at international conferences in the coming months.
In the coming days we will be updating you on the movements of the bird that went to Iran, so revisit this site.
Locations of 11 adult Egyptian vultures tracked between January and October 2018.
Of all the Egyptian vultures we fitted with transmitters in January 2018, only one left northeastern Oman. Until mid April, 171318 moved back and forth between Sur and Musandam, then finally crossed to Qeshm Island. Since then, (and as of today) it has remained on Qeshm Island, and the nearby mainland. The first map below shows the movements of 171318 during June-September 2018. The second map shows what it did during 27 September, and the third map zooms in on that showing that the bird spent much of its time perched on pylons (one can see the shadows of the pylons on which the bird is perched located at about 11 o'clock from the cluster of locations).
Movements of Egyptian vulture 171318 during June-September 2018
Movements of Egyptian vulture 171318 on 27 September 2018
Clusters of locations for Egyptian vulture 171318 on 27 September 2018. The shadows of pylons on which the bird is perching can be seen at about 11 o'clock to the clusters (click on image to enlarge).