Update for 6490

 Continuing the post-spring migration updates for the birds we are tracking....

A Greater spotted eagle at Al Jahra, Kuwait during winter 2021-2022.

6490 is an adult female Greater spotted eagle that was captured and fitted with a tracking device on 15 December 2021 at Al Jahra, Kuwait.  It remained at Al Jahra for the winter, and commenced spring migration on 27 March 2022.  Migration took it through southern Iraq, Iran, Turkmenistan, and Kazakhstan.  It crossed the Kazakhstan border on 15 April.  Straight line distance between Al Jahra and its current location is about 3700 km, spanning about 30 degrees of latitude! See map below.

Spring migration 2022 of an adult female Greater spotted eagle between Kuwait and Russia (© KEL/KFAS).

Since arriving in Russia, it has wandered quite a bit (See map below).  Although 6490 is an adult, it does not appear that it will breed in this year because it has yet to settle into a limited home range.  Currently it is about 115 km NNE of the Russian city of Tobolsk, which has its own interesting history.  A close look at 6490's locations shows it to be frequenting wet forest areas, typical habitat for this species, whether or not it is breeding.

Movements of an adult female Greater spotted eagle (6490) since arriving in Russia on 15 April 2022 (© KEL/KFAS).

Locations (23 May 2022) of an adult female Greater spotted eagle (6490) that wintered in Al Jahra, Kuwait during winter 2021-22(© KEL/KFAS).

Update for 6489

Greater spotted eagle at Al Jahra, Kuwait (© KEL/KFAS).

Spring migration is more or less over for the birds we are tracking.  That means that eagles that are going to breed in 2022 should be on their breeding territories, building nests and preparing to lay eggs.  Other eagles will not be breeding this year, including birds that are too young and those that are old enough, but have not yet found a territory/mate.  A good example of this can be seen from our tracking data for Greater spotted eagle 6488, which was tracked when it did not have a territory in 2020, and when it did in 2021 (See these earlier postings here, here, and here).

Over the next days/weeks I'll try to update the situation with each of the eagles we are tracking.  Today is the turn of 6489, a female that was hatched in 2019 (we know this from its plumage) and caught by us on 15 December 2021 at Al Jahra.

Map below. After release, 6489 remained at Al Jahra until the morning of 9 April 2022, when it departed on migration.  By 19 April it crossed the northern border of Iran and entered Turkmenistan.  It stopped over at a location along the southern boundary of the Aral Sea in Usbekistan during 21 April - 4 May. On 15 May it arrived at Kuspek Lake at Kuspek, Kazakhstan.

Spring migration of a subadult female Greater spotted eagle (6489) during 9 April - 19 May 2022 (© KEL/KFAS).

At the time of this posting 6489 has been settled at Kuspek Lake, especially within a small area of woodland to the south of the lake and not far from human habitation.  See maps below. We don't know whether it will stay there this summer.  Because it is a young bird, it might wander.  We'll have to wait and see.  If it survives and migrates in autumn, it may spend next winter at Al Jahra.

Locations of Greater spotted eagle 6489 at Kuspek, Kazakhstan, 15 - 19 May 2022 

(© KEL/KFAS).

Concentration of locations of Greater spotted eagle 6489 at Kuspek, Kazakhstan, May 2022.  Most locations are within a line of trees about 250 m in length. 

(© KEL/KFAS).

6488 returns to 2021 summer territory

Greater spotted eagle (6488) after arriving back at Al Jahra, October 2021.

We have been tracking a Greater spotted eagle (6488) since January 2020, when we caught it at Al Jahra, Kuwait.  In summer 2020 it wandered widely in the breeding range, and did not hold a breeding territory (below left). In winter 2020-21, it returned to Al Jahra, then migrated in spring and settled into a territory in summer 2021 at a location about 90 km SE of Chelyabinsk, Russia (below right).  The blog we did for summer 2021 is here.

Movements of a Greater spotted eagle (6488) during January 2020 - October 2021.  Right panel: 2020 movements, Left panel: 2021 movement. Blue = winter movements, Purple = spring migration, Red = summer movements, Green = Autumn migration. ©KEL and IAR.

In winter 2021-22, it was again at Al Jahra, and on 25 March it left on spring migration, and has arrived back at the same summering location it used in 2021 (See below).  The breeding season is still young, so we don't yet have a clear indication whether this bird will breed in 2022.  

Breeding season locations of a Greater spotted eagle (6488) in July 2021 (purple) and April 2022 (yellow). ©KEL and IAR.

It is interesting, but not unusual for eagles to show fidelity to their breeding and wintering places.  One Greater spotted eagle tagged at a nesting site in Poland, returned every year for ten years.  That bird also showed fidelity every year to its wintering area, which was along the upper reaches of the Nile River on the border between Sudan and South Sudan.

Winter 2021-22, Long-legged buzzards

Long-legged buzzard (Buteo rufinus). Photo: © Christoph Moning via e-bird https://ebird.org/species/lolbuz1 

The winter has passed, and most of the raptors that wintered at Al Jahra have migrated. During the winter of 2021-22 we were able to deploy GPS tracking devices on more raptors, so that currently we are tracking six Greater Spotted Eagles, two Steppe Eagles, and two Long-legged Buzzards.  All of those have embarked on their spring migration, and some have already reached breeding areas in Europe and Asia.  In the next few posts, we'll catch up with what the tracked birds are doing.

In late March we captured two Long-legged Buzzards (Buteo rufinus), and fitted them with transmitters.  Long-legged Buzzards are rather large buzzards with a very big distribution (See below).  They are considered of Least-Concern in terms of conservation because of their wide distribution and large population size (See here).  They feed on a variety of animals, including snakes, lizards, and small to medium sized mammals.  You can read more about them here. 

Distribution of Long-legged Buzzard.  Yellow = Native Breeding, Dark Green = Native Resident, Light Green = Passage, Dark Blue = Native Non-breeding.

After wandering around a bit in Kuwait, both birds (8696 and 8697) recently started on migration.  8696 started proper migration on 12 April, and 8697 started on 6 April.  See the maps below.  As of today, both birds are in north-central Iran.  Although both birds are currently within the breeding grounds, we'll have to wait to see where they eventually settle.  In fact they might not settle, but could spend the summer living a rather nomadic lifestyle, moving from place to place in search of food.  Of course if they do that, they will not hold a territory and will not breed.

Movements of a Long-legged Buzzard (Buteo rufinus, 8696) during 22 March - 15 April 2022. ©KEL and IAR.

Movements of a Long-legged Buzzard (Buteo rufinus, 8697) during 27 March - 15 April 2022. ©KEL and IAR.

Roosting

Roosting is when birds perch in one place to rest, sleep, or avoid bad weather.  The locations of roost sites are such that they protect the roosting bird from the weather and from potential predation, especially by ground predators.  Thus, roosts are often in larger trees, under sheltered overhangs on cliffs or in dense vegetation.  

Roosting can occur during the day or the night. Birds that are more active during the day (diurnal birds like Greater spotted eagles), are more often awake when roosting during the day than when roosting during the night.  The reverse is true for nocturnal birds, like owls.

Most birds roost individually, but some species roost communally in groups, which can be large.  For example, roosts of Amur falcon (Falco amurensis) can hold thousands of birds (see this site).  The composition of the groups can vary in relation to age, breeding status and season.  A variety of raptor species roost communally, including eagles.  Indeed, scientists have used feathers shed by eagles at roost sites as sources of DNA, and used that information to estimate population sizes (see this paper)

An Amur falcon (Falco amurensis) roost tree in NE India. photo: Ramki Sreenivasan

Greater spotted eagles at Al Jahra also roost, and they can be seen doing so during the daytime.  However, it seems that they also might form loose groups to roost at night.  Photos taken using a drone late in the day, show Greater spotted eagles roosting together in a Prosopis juliflora tree.  The tree is surrounded by wet areas and reeds, so probably quite secure from ground predators, and well away from roads and lights.  (A side note is that Prosopis juliflora is an invasive species that has spread across many areas of Arabia.  Its greenness is appealing, but it is a pest species that should be removed when possible.  The problem is that it is very hard to remove.

Six Greater spotted eagles (Clanga clanga) roosting in a Prosopis juliflora tree at Al Jahra 2022.  © R. Hajji.

Apart from providing a secure place to rest, roosts can sometimes be a location where information can be exchanged.  This has been shown in vultures from the Americas (see this paper).  What happens there is that birds at the roost watch other birds as they come into the roost to see if they show signs of feeding (having a large crop), then they follow those birds the next day when they leave the roost, hoping they will lead them to food. 

Colour morphs of GSE

Dark and light (fulvescens) morphs of Greater spotted eagle at Al Jahra Pools, Kuwait, January 2022. © M. Gholoum

Quite a few raptor species display different plumage colours.  For some, like the Common buzzard (Buteo buteo) the variation seems to be continuous from very light coloured birds to very dark and all the variations in between (Look here).  In other species, the variations segregate into two rather distinct types: dark and light.  These different colour types are called "morphs", and some well-known examples are found in Booted eagle (Hieraaetus pennatus) and Eastern screech owl (Asio otus). See below. These colour differences sometimes earn the individuals a sub-specific classification, or at least a special name.  So, the grey variation of the Screech owl is sometimes called the McCall's morph or Asio otus mccalli, and the red variation is sometimes called the Northern morph.  In the past, colour variation sometimes lead taxonomists to believe the variants to be completely different species.

Two colour morphs are also observed for Greater spotted eagle (photo above).  By far the most common is the dark morph, in which the feathers are dark brown.  Much rarer is the light or fulvescens morph.  Little is known about this morph. except that it is rare, and it seems to occur more commonly in the eastern part of the breeding distribution, and is more common in winter in Arabia and India.  An informative article on this can be found here  http://docs.sibecocenter.ru/programs/raptors/RC28/RC28_89-104_ShortReports.pdf, starting on page 96.  The lead author on that article tells me that there have been more observations of fulvescens in that part of Russia in recent years.  At least two light coloured morphs of Greater spotted eagle have been wintering at Al Jahra Pools during 2021-22. 

Two colour morphs of the Booted eagle (Hieraaetus pennatus). Images from https://eunis.eea.europa.eu/species/1075. 

Two colour morphs of the Eastern screech owl:  the northern (reddish) morph and McCall's (greyish) morph. Images from https://www.allaboutbirds.org/guide/Eastern_Screech-Owl/id.

8749 moves to Iran

Release of a Greater spotted eagle at Al Jahra, Kuwait, after fitting it with a GPS-GSM tracking device (December 2021). © KFAS/KEL/IAR

Most of the Greater spotted eagles that we have captured at Al Jahra and tracked have remained mostly on the reserve.  Some have made short trips to agricultural areas nearby (see here, for example), others have left the reserve for a matter of hours, and 6491 even went to near Basra for a short while before returning to Al Jahra (here).  

8749 has acted differently in that it remained at Al Jahra until 8 January, then moved north, and, eventually crossing into Iran on 14 January.  Below is a map of 8749's movements since 1 January.  One obvious feature that contrasts with the data from the other birds we have tracked is that there are so few data since it has moved into Iran.  The reason for this is that the GSM network in that part of Iran is rather weak, and the only data that are uploaded are those that can be squeezed into the message from the tag when it makes contact with the GSM network once a day.  Once it moves back into a stronger network, the tag should upload data that it has stored on-board, and so fill in the gaps.

Movements of a Greater spotted eagle (8749) during 1 January -16 February 2022.  Yellow point is most recent location. © KFAS/KEL/IAR