This is a blog about vultures in Djibouti. Please feel free to comment. You can click on the images and they will open up larger in a new window and be easier to see. Also, you can translate the text by using the translate gadget on the right side of this blog.

Wednesday, May 20, 2020

More about Mabla (216)

by H. Rayaleh and M. McGrady

As noted in an early post, Mabla (logger Id=216) appears to be a floating Egyptian vulture, and does not have a fixed territory.  Recently it has settled into the area around Hayu, Ethiopia.  It appears that Hayu is a small collection of buildings that service people and businesses moving between Ethiopia and Djibouti.  These places seem to be good for scavengers like Egyptian vultures.  Back in 2013, the vulture we were tracking (Assamo) spent time at a similar road side settlement near Ali Sabieh https://egyptianvulturedjibouti.blogspot.com/2013/06/
Movements by Mabla during 15 -20 May 2020.

Mabla's movements near Hayu, Ethiopia in May 2020.

Sunday, April 26, 2020

Tale of two vultures

by H. Rayaleh and M. McGrady

We are continuing to hear from the Egyptian vultures we tagged in Djibouti earlier this year.  As with the adult Egyptian vultures we tagged in Oman http://egyptianvultureoman.blogspot.com/, most of them appear to be territorial birds that move regularly between their territory and the abattoir at Tadjoure, where we caught them.  The territories are in cliff-rich terrain where they are probably nesting, at least some of them.  A few seem to be either unattached to a territory or less territorial because they may not be breeding this year.  Below are examples of a territorial bird (217, purple) and one that seems to be a "floating" bird (216, red).  Interestingly, the floating bird visited Ethiopia, returned to Djibouti (near Tadjoura), then headed again to Ethiopia and back to Tadjoura.  During that second Ethiopian sojourn it flew farther south, and was not so far from Adigala.  Look back at the maps of "Assamo" the Egyptian vulture we followed in 2013.
 https://egyptianvulturedjibouti.blogspot.com/2013/08/adigala.html .  Assamo, also spent a lot of time in Adigala.  I wonder what is so attractive there.

Movements of two adult Egyptian vultures during February - April 2020.  The red dots (216) are from a bird that apparently does not hold a territory, and wonders widely.  The purple dots (217) are from a bird that apparently holds a territory and regularly visits Tadjoure, Djibouti to feed.

Friday, April 3, 2020

Territory holders vs floaters

by H. Rayaleh and M. McGrady

In our previous post we showed maps of four territorial birds, and an apparently non-territorial bird.  The map below illustrates again how the behaviour of territorial birds differs from that of an apparently non-territorial "floating" bird.  At this time of year, territorial breeding vultures will be defending their territories against intruders, conducting courtship and producing eggs and young.  Of course, they still have to feed.  Floating birds don't have the burden (or benefit) of holding a territory, so they wander.  Those wanderings may include dwelling in some places for some limited amount of time, but they really are not tied to any locations.

Movements of three adult Egyptian Vultures during February and March 2020.  Blue and Green are territorial birds that occassionally travel to Tadjoura, presumably to feed.  Yellow is a wandering bird, with no fixed abode.

Wednesday, April 1, 2020

They seem to be resident

by H. Rayaleh and M. McGrady

So far, it seems that the birds we marked in Tadjoure in March are all resident birds; they were all adults.  Below is a map of some of the birds we are tracking.  If you double click on the map you should be able to see a full screen view. The map illustrates that some are probably territory holders (blue, green, red), and may be breeding now (its spring and love is in the air), and at least one is seemingly unattached to a territory, and wandering more widely.  The territory holder are occassionally visiting Tadjoure, presumably to feed at the abattoir there, from time to time.

Please, everyone stay healthy.

Movements of Egyptian vultures during March 2020.

Sunday, March 8, 2020

New tracking initiative starting in 2020

by M. McGrady and H. Rayaleh

Mabla (216) being released by Houssein
This blog post marks the re-activation of  the Egyptian vultures in Djibouti blog, after a pause of over a year.  During 10-22 February 2020 we did field work in Djibouti on Egyptian vultures that followed up on our work in 2013.  In 2013, we fitted a single sub-adult Egyptian vulture (Assamo) with a GPS-PTT (satellite transmitter), and tracked it for about 18 months.  During that time, it moved between two centres of activity, one north of Tajoura, Djibouti and one near Adigala, Ethiopia.  We never got to the bottom of why that bird made such long journeys between those centres, but we did write a paper that used those data and data from Oman http://egyptianvultureoman.blogspot.com/ to examine the movements of non-breeding Egyptian vultures.  You can download that paper from the 24 Jan 2014 blog post https://egyptianvulturedjibouti.blogspot.com/2019/01/new-publication-using-data-from-assamo.html.

Anyway… during our 2020 field work we fitted 7 adult Egyptian vultures with satellite transmitters. In the coming weeks/months/years we will be posting updates about these birds every so often.  So as to get started, below is a map of the movements of Mabla (pictured above) since it was tagged on 16 February.  Unlike the others that we tagged, Mabla does not appear to be a territory holder, but has wandered over to near Semera, Ethiopia.  

Please follow this blog to keep up to date, and let others know about it.  We'll be posting more soon.

Movements of Mabla, an adult Egyptian vulture during 16 February - 8 March 2020

Thursday, January 24, 2019

New publication using data from Assamo

Egyptian vulture captured in Oman in 2018.
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.  See  http://egyptianvultureoman.blogspot.com

Wednesday, September 26, 2018

Assamo... an update...finally

Last post to this blog was in 2014!  However, Assamo has been transmitting intermittently since then. 

Below is a map of its movements during the time it has been tracked.  It has turned out that Assamo is, indeed, a resident (not migratory) Djiboutian.  The most recent locations are from June 2018, and were from near Obock.  That means Assamo has been being tracked for over 5.5 years, and he is at least about 10 yrs old.

The reason this tag is not transmitting regularly is not known, but may be because the long feathers on Assamo's neck are partially covering the solar panels at time.  No matter... it is good that some data are coming in, and that the bird appears to be alive.

Movements of a Egyptian vulture tracked in Djibouti during 2013-2018.  Green lines are roads and dark grey lines are high voltage powerlines.  Many locations are along roads and powerlines, where birds perch.

Locations from June 2018 near the town of Obock, Djibouti.