Tuesday, 15 April 2014

Wattled Starlings at Bahri

Since February we have regularly been seeing flocks of Wattled Starlings at Bahri Sewage Pools, but on Saturday the flock was bigger than ever with up to 200 birds present. We tried to catch some, but as with our previous attempts we had no luck. The flock was about a 50:50 mix of adults and juveniles and it seems pretty certain that they must be breeding in the area. Nikolaus describes the species as a non-breeder and "fairly common in the southeast, rare elsewhere". By 'the southeast' he must be referring to what is now South Sudan, so they must have been quite rare in what is now Sudan. It seems that they have either changed their status here or were previously overlooked. I have seen quite a few elsewhere, including at Soba sewage pools and several times at the KICS stables, so I find it hard to believe they were overlooked.

Adult and juvenile Wattled Starling, Bahri Sewage Pools, 12th April 2014

We wanted to follow up on our capture last week of a Clamorous reed Warbler, so we tried playing some recordings (downloaded from Xeno Canto of birds in Egypt). We had no success, until we tried the area where we caught the bird last week. We had two birds calling back at us. One came in very close, but mostly stayed hidden from view. Hopefully we will be able to establish if there is a resident population here. Last week we also saw our first Crested Coot at Bahri and one was present again on Saturday. It is nice to confirm that they are not just at Khartoum sewage works. Interestingly, we saw none while the Eurasian Coots were here. They have now all left. 

Crested Coot, with Little Grebe, Bahri Sewage Pools, 12th April 2014

It is not often you get good views of a long-tailed Nightjar, but this one showed well after it was flushed from its day roost by a Spur-winged Lapwing. Here it can still be seen harassing the nightjar.

Long-tailed Nightjar and Spur-winged Lapwing, Bahri Sewage Pools, 12th April 2014

Last week we had a couple of Slender-billed Gulls at the site, but they had gone and were replaced by a group of 16 Black-headed Gulls.

Black-headed Gull, Bahri Sewage Pools, 12th April 2014

Wednesday, 9 April 2014

Clamorous Reed Warbler netted at Bahri

In my previous post I discussed the hybrid weaver we netted last Saturday at Bahri sewage pools. However, we also saw some other good birds including a Clamorous Reed Warbler, which we netted. Nikolaus shows one record from the Nile Valley up near the Egyptian border, and shows a resident breeding population on the Red Sea coast, but nothing from anywhere near Khartoum. In this part of the world the species is non-migratory, which implies the species might have either spread down the Nile or somehow crossed from the Red Sea. I am very interested in finding out its origins, as Marwa and I are currently preparing a paper of our recent records, which discusses the potential spread of bird populations along the Nile between the Afrotropical and Palaearctic regions. This could be a good example of a species moving southward. Apparently, the Egyptian and Red Sea populations are a different subspecies, but the biometrics of this bird (see below) appear to be inconclusive.

Wing - 82 mm
Tail - 76 mm
Bill tip to skull - 25.1 mm
Bill tip to feathering - 20.7 mm
Bill depth - 5.5 mm
Bill width - 4.6 mm
Total head (bill tip to back of head) - 47 mm
Tarsus - 29.1
Weight - 29 g
Total length (hard to measure on live bird) 183 mm, then 190 mm, then 185 mm
P2 = P7
Longest primaries - 3 and 4
Emargination - 3 and 4 (with slight hint on 5th)

I hope to follow up on this bird to determine if there is a resident population at Bahri and to find out which form it is. Perhaps this can be done with tape playback.


Clamorous Reed Warbler, Bahri Sewage Ponds 4th April 2014

Wing of Clamorous Reed Warbler, Bahri Sewage Ponds 4th April 2014

There were plenty of other good birds around including lots of Sacred Ibis. There have been lots about all winter, but Nikolaus describes them as a summer visitor, so again this appears to be a recent change of status. Two Slender-billed Gulls were present, and a group of 22 African Openbill Storks was an uncommon site this far north. There were fewer migrants this week, but still plenty to look at.

Sacred Ibis, Bahri Sewage Ponds 4th April 2014

African Openbill Storks, Bahri Sewage Ponds 4th April 2014

Slender-billed Gull, Bahri Sewage Ponds 4th April 2014

Whiskered Tern, Bahri Sewage Ponds 4th April 2014

Wood Sandpiper, Bahri Sewage Ponds 4th April 2014

Friday, 4 April 2014

Probable Cinnamon X Northern Masked Weaver hybrid?

I visited Bahri sewage pools again today with Marwa to ring some weavers. For the first time we noticed a small group of Cinnamon Weavers near to the Northern Masked Weaver colony we have been netting at recently. It was nice to see them, but it does mean that it will be much more difficult to know what I am catching now, as the females seem to be almost identical and one of my main aims is to find a way to separate the two. So far my concerns have been about the identification of the females and non-breeding males, but today we caught a bird that threw another spanner in the works, as it seems to be a male that is intermediate between the two species. I wonder if it might be a hybrid - a distinct possibility given the similarity of the females, the almost identical nesting behaviour, and the presence of both species breeding together at one site (I assume the Cinnamon weavers are breeding nearby, as they were in breeding plumage).

Note that the bird is moulting out of its non-breeding (basic) plumage, which is why it still has some pale brown feathers on the head and whitish feathers on the underparts. This is nothing to do with it being a probable hybrid.

Probable Cinnamon x Northern Masked Weaver hybrid, Bahri Sewage Pools 4th April 2014

Probable Cinnamon x Northern Masked Weaver hybrid, Bahri Sewage Pools 4th April 2014

Probable Cinnamon x Northern Masked Weaver hybrid, Bahri Sewage Pools 4th April 2014

Probable Cinnamon x Northern Masked Weaver hybrid, Bahri Sewage Pools 4th April 2014

I have included some photos of male Northern Masked Weavers in breeding plumage below for comparison. Although the cinnamon colouring around the head and on the breast is quite variable, I have never seen anything close to the bird caught today.

Northern Masked Weaver

Northern Masked Weaver

Northern Masked Weaver

Northern Masked Weaver

From the photos above you can see that the hybrid has a lot more chestnut on the crown and underparts than the Northern Masked Weavers. It also has a bit more black on the crown than most Northern Masked, but less than most Cinnamons (see below), though the extent of black on the head of Cinnamon Weavers varies a lot, from little more than a face patch to almost a complete hood. The photos above show that the upperparts of the hybrid are much more like Northern Masked, being bright yellow rather than golden, though it does have a couple of the golden feathers (for example on the coverts of the open wing shot) that are more typical of Cinnamon.

Cinnamon Weaver

Cinnamon Weaver

Cinnamon Weaver

Cinnamon Weaver

This hybrid individual (I will assume this is a hybrid unless good evidence arrises to prove otherwise) is very similar to photos I have seen of Yellow-backed (or Black-headed) Weaver Ploceus melanocephalus. In particular, the yellow nape and upper parts contrasting with dark head and cinnamon underparts is quite distinctive. The main difference is that this hybrid bird has a black and cinnamon head, while Yellow-backed Weavers have an all black head. This species is found in South Sudan and in Eritrea and Ethiopia up to the Sudan border. Potential hybrids will clearly have to be considered when identifying birds in any of these areas, where all three species could occur.

Saturday, 22 March 2014

Good painting of Red Sea swallow on photo bucket

I was just searching on Google for 'Red Sea Swallow' and I came across this good painting of one on photo bucket. I thought I would add the link here as others might be interested in seeing what they would look like if anyone ever gets the chance to see one. It was uploaded by Carlos Urdiales.

photobucket.com/Hirundoperdita.jpg

Tom

Thursday, 20 March 2014

Netting in Sennar

I have been on my mid-semester break this week, so I decided to head down to Sennar for a couple of days of ringing. My main hope was to try and catch some Cinnamon Weavers in non-breeding plumage. First priority was to locate the non-breeding flocks, so I drove around with my local helper Mohamed to try and find some birds. We also saw other good birds on our travels, with the best being my first ever Zebra Waxbills. We saw about 40 in total in two locations a few km apart. Although found throughout South Sudan, they have only previously been reported in Sudan from Darfur, making this a considerable range extension for the species. Some Winding Cisticolas were also in the same reed-filled ditches.

Zebra Waxbills, near Sennar March 2014

Winding Cisticola, near Sennar March 2014

We headed down to a farm beside the Blue Nile owned by a friend Husam. We could't find any weavers in the area and Husam commented that they sometimes bred nearby, but mostly were in the fields along the irrigation ditches, which is where I was netting them back in October and November. There were a few good birds around, including an African Skimmer fishing on the river, plus an Osprey, a yellow-billed Stork and some Grey Herons.

African Skimmer, near Sennar March 2014

We headed back to the main nesting areas the next morning and found some big flocks of weavers in some of the fields, but it was very open and the birds were unapproachable, so it was necessary to set nets at the field edges near some bushes. This was not very successful and all the first birds I caught were Village Weavers. Closer observation showed that most birds in the flock were this species, so we moved to a new location near where we had seen the Zebra Waxbills, where we had also seen a few Cinnamon Weavers. There were not many around and we only caught 4. However, as always, there were some other good birds that entered the nets. Most exciting was a couple of Malachite Kingfishers, which proceeded to put on a bit of a display.

Malachite Kingfisher, near Sennar March 2014

Malachite Kingfisher, near Sennar March 2014

Another surprise was this Squacco Heron which flew up into the net when we were trying to flush some weavers from a bush.

Squacco Heron, near Sennar March 2014

Cinnamon Weaver, near Sennar March 2014

I was very pleased to catch this Eastern Bonelli's Warbler. I have been looking out for them for a long time, but without success and this was my first in Sudan. Warblers are often very difficult to observe well in Acacia trees and many interesting birds have to be left unidentified. This is one area where a mist-net can be a big help. I was surprised with how bright the rump was, as this is not a feature I have noticed when I have seen this species in the field. Usually the bright yellow-green edges to the flight feathers are more easily noticeable.

Eastern Bonelli's Warbler, near Sennar March 2014

Black-Scrub-Robin, near Sennar March 2014

Isabelline Shrike, near Sennar March 2014

I have seen surprisingly few Red-billed Queleas in Sudan. Sometimes referred to as the Sudan Dioch, this species is renowned for forming huge flocks that decimate farmers crops, and they are supposedly abundant in the area of the Gezira Scheme, the large area of land between the two Niles irrigated by various canals and ditches. This is the first time that I have seen big numbers of them in this area. 

Red-billed Quelea, near Sennar March 2014

Rufous Scrub-Robin, near Sennar March 2014

Although they are supposedly present, I have yet to see a Tawny-flanked Prinia anywhere around Khartoum, where the Graceful Prinia is ubiquitous. On this trip there seemed to be Tawny-flanked Prinias all over the place. I wonder where the cut off point is in their distribution, or whether there is a place where one species gradually gives way to the other.

Tawny-flanked Prinia, near Sennar March 2014

While using nets I do not carry my camera, so I was unable to take shots of a female Black-bellied Bustard that flew overhead at the ringing site. Fortunately, I had my binoculars and the evening before I had been brushing up on the identification of bustards, so I was able to tell what it was. This is my first sighting of a bustard in Sudan. I am very keen to see some of the others.

Grey-crowned Crane - a new species for South Sudan

I recently received information about this record of 4 Grey-crowned Cranes in Juba by Henrik Mikkelsen on 31st October 2013. He first heard the sound and then looked up to see 4 cranes flying overhead heading north. The colouring of the cheek in the photo below (mostly white with a red patch above) clearly shows that these were Grey-crowned Cranes. The Black-crowned Cranes that are known from South Sudan have mostly a red cheek with a paler patch above. To my knowledge, this is the first record for the country. Birds of South Sudan (1989) by Gerhard Nikolaus gives no records, but mentions that it "might occur as a visitor from Uganda along the southern border". Congratulations to Henrik on an excellent record, and thanks also for giving permission to publish his record and picture. He tells me he saw around 200 species during his 6 month stay in Juba. I would love to hear about his other records.

Grey-crowned Crane, Juba 31st October 2014 (Henrik Mikkelson)

Tuesday, 11 March 2014

Active nesting of Northern Masked Weavers at Bahri

On Friday I visited Bahri Sewage Pools again with Marwa. We visited the same area as last week, placing two nets close to where some weavers had built some nets. We had less success with the nets than last week and I only caught 7 new Northern Masked Weavers, many of which were showing some body moult with yellow feathers on the underparts, but none of which were in full breeding plumage. We also caught a couple of Village Weavers, a Reed Warbler and a heap of House Sparrows. Once again, we had about 50 Wattled Starlings flying around close to the nets, but again none went in. Unlike last week, I noticed that a number had the full wattles of birds in breeding plumage. After a while the wind picked up and we packed the nets up early.

We checked the main pools on the way out and were struck by the large numbers of weaver nests that had recently been constructed. One group of 16 nests was about 30 m out in the water in the branches of a flooded bush. There were then two other colonies close by that were built in patches of reeds beside the road, one with 29 nests and the other with 17. It was noticeable that the males around this area were in full breeding plumage. All nests were above water and the ones in reeds were between about 1 and 1.5 m above it. The ones further out in the bush were perhaps a little lower. Not all nests were complete and there was clearly still a lot of activity going on. Some males were already hanging below the nests and flapping their wings to attract females. I hope to get back soon to check on the nest contents.

Northern Masked Weaver nests in bush, Bahri Sewage Pools 7th March 2014

Northern Masked Weaver nests in reeds, Bahri Sewage Pools 7th March 2014

The most conspicuous birds, once again, were the large flocks of Ruff, with several thousand present but very difficult to actually count. Ducks were fewer in numbers, with mainly Gargany present and only a couple of Shovelers. There were still a couple of Eurasian Coots, several Western Marsh Harriers and we had a group of over 20 Senegal Thick-knees roosting under some bushes.

Ruff flocks, Bahri Sewage Pools 7th March 2014

Eurasian Coot, Bahri Sewage Pools 7th March 2014