Friday, 12 September 2014

Breeding of African Purple Swamphen finally confirmed

I visited Khartoum Sewage Ponds today with Marwa and we were joined by a couple of friends, Basim and Jeanette. There were lots of terns about, which all appeared to be White-winged, plus quite a few waders, with large numbers of Black-winged Stilt, Ruff, Wood Sandpiper, and Spur-winged Lapwing and smaller numbers of Little Stint, Common Ringed Plover, Kittlitz's Plover, Temminck's Stint, Curlew Sandpiper, Black-tailed Godwit, and Marsh Sandpiper. I had my highest ever count of Hottentot Teal, with 48, plus a few Northern Shovelers.

Northern Shoveler, Khartoum Sewage Pools 12th September 2014

As has so often been the case at this site, the gallinules stole the show. We saw about 8 African Purple Swamphens, which is remarkable for a bird which is generally quite shy. For the last two and a half years we have been hoping to spot a young bird to confirm them as a breeding species, and finally we were in luck today with brief views of a bird in juvenile plumage. There were the usual big numbers of Common Moorhens, and as always there were quite a few young birds present, but for the first time we saw some pairs with very young chicks. I counted 28 Crested Coots, which, as in all previous visits, were in breeding plumage.

Crested Coot, Khartoum Sewage Pools 12th September 2014

Young Moorhen, Hottentot Teals and Crested Coot, Khartoum Sewage Pools 12th September 2014

I am particularly pleased to get the last shot, as, according to the published literature, it could never be Sudan. Common Moorhen is not recorded as a breeder, Hottentot Teal is known from only a single record, and Crested Coot has no published records. I demonstrates how little the avifauna of this country has been studied.

Sunday, 7 September 2014

Extensive feather wear of breeding male weavers

We must be nearing the end of the breeding season for the Northern Masked weavers at Bahri, because some of the males have started moulting out of their breeding plumage. I first reported them nesting way back in early February, making it a long season. However, a few birds are still building nests, so it is not yet completely over. Looking at the birds this weekend it was noticeable how worn the wings had become. The very high population density at Bahri means that I don't get many recaptures of ringed birds, but on Friday we caught two - I photograph the wings of every bird I catch, so this gave me a good opportunity to see how their wings have changed.

Male Northern Masked Weaver 158, Bahri 29th March 2014 

Male Northern Masked Weaver 158, Bahri 5th September 2014

The ring of bird 158 in March

The ring of bird 158 in September

Bird 158 (above) was first caught back in March, and then again on Friday. It is clear from the two photos that in the last 6 months the feathers have become highly abraded at the ends, have faded a lot, and that some ends have broken off completely. The effects of bleaching by the sun are equally evident on this bird's leg ring (above). One reason I include the ring shot is to prove that they are the same bird. The above wings are so completely different that I twice went back to my original photos (which include a series of head and body shots), to make sure that there was no mistake. Presumably the greater coverts have been changed recently, as they had narrow white edgings in March and thicker yellow ones in September.

Male Northern Masked Weaver 291, Bahri 23rd May 2014

Male Northern Masked Weaver 291, Bahri 5th September 2014

Bird 291 (above) was already looking quite tattered back in May. In the last few months there has been a lot of additional wear to many of the feathers, but there has also been some attempt at repair, as the broken primary 7 (numbered ascendantly, where the outermost feather is number 1) has clearly been replaced. There was no other sign of primary moult, so this was just a single replacement. However, the tertials and greater coverts are dark centred with bright yellow edgings and therefore must also be new.

Male Northern Masked Weaver 337, Bahri 5th September 2014

Hybrid male Northern Masked x Cinnamon Weaver 329, Bahri 5th September 2014

Many of the other males (above) also showed extensive feather wear and damage. However a comparison with some of the females (below) shows that they seem to have suffered far less.

Female Northern Masked Weaver 326, Bahri 5th September 2014

Female Northern Masked Weaver 334, Bahri 5th September 2014

Female Northern Masked Weaver 338, Bahri 5th September 2014

Although these females have received a lot of abrasion, they lack the more extensive damage seen on most of the males. There must be some behavioural difference causing this such as the activities of males during nest building, or display - where the males hang under nests and flap their wings whenever a female passes. The brushing of the wings on surrounding branches during display must cause some of this damage. There could also be damage caused by aggressive interactions between males, though this is something I have not seen much of, or it could just be that they spend so much time building nests and showing them off to females, that they have little time for feather care.

Juvenile Northern Masked Weaver 333, Bahri 5th September 2014

Juvenile weavers (unlike many other passerine families) have a complete post-juvenile moult, which means that when they moult out of their juvenile plumage they also change their flight feathers (which most passerines do not do). From what we have seen above we know that a lot of wear will occur in the coming breeding season, which helps explain why these birds need to moult their juvenile primaries to ensure that they will last the rest of the year. Juvenile number 333 (above) had already starting to moult its flight feathers (9 is in pin, 10 is three-quarters grown, while 1 to 8 are the old juvenile feathers). However, this bird still has fresh primaries that will easily last it for the next few months, which raises the question of why they need to moult them now. Surely a better strategy would be to moult them at the start of the breeding season, which is when they will already be moulting their body feathers into alternate (breeding) plumage. They would then have a new set of primaries that could more easily cope with the wear and tear of the coming nesting season. I wonder why they do not do this.

Saturday, 6 September 2014

Another hybrid weaver at Bahri

For the last two weekends Marwa and I have been netting weavers at Bahri sewage pools. Yesterday we caught our second Cinnamon Weaver x Northern Masked Weaver hybrid. As with the previous one, the underparts had extensive cinnamon colouring and there was a lot of black on the head forming a slight hood - which are Cinnamon Weaver features. However, as with the previous bird, the upperparts were much yellower, and more like Northern Masked. Again, the yellow nape was one of the most conspicuous differences that separated it from Cinnamon (for comparison see the photo of a Cinnamon weaver at the top right in the header of this blog). This hybrid had a wing of 75 mm, which is intermediate between the 76 mm average of male Cinnamon and 74 mm average of male Northern Masked, though there is extensive overlap between the two. See here for the report of the previous hybrid.

Hybrid Cinnamon x Northern Masked Weaver, Bahri 5th September 2014

Hybrid Cinnamon x Northern Masked Weaver, Bahri 5th September 2014

Hybrid Cinnamon x Northern Masked Weaver, Bahri 5th September 2014

The migrants are already starting to move through. Last week we saw a Southern Pochard and a Gargany, there have been reasonable numbers of White-winged Terns and there have been lots of waders of different species. There were quite a few Yellow Wagtails yesterday and we also saw a Wryneck, while last week we saw a Southern Grey Shrike. We have yet to see any warblers though.

Senegal Thick-knee, Bahri 5th September 2014

Village Weaver pecking at a Northern Masked Weaver, Bahri 5th September 2014

Saturday, 23 August 2014

First trips out after my summer break

I arrived back from my summer break a couple of weeks ago. I have yet to make any lengthy birding trips, but I popped out a couple of times to my local patch at the Soba Hospital sewage ponds. I was particularly interested in trying out some new recording equipment, but with little success, so I did not take any photos.

It was interesting to see that the Northern Masked Weavers are still nesting, with some birds still actively nest-building. Many of the rainy season visitors are still present, such as White-throated Bee-eater, Greater Blue-eared Starling, Abdim's Stork and Fulvous Whistling Duck; plus a number of migrants and winter visitors have already arrived, such as Gargany, Shoveler, Purple Heron, Night Heron, Little Stint, Common, Wood and Green Sandpiper, and White-winged Tern.

As is usual at this time of year, much of the area around the pools was flooded, which made it hard to see all of the birds and many would have been hiding in the thick vegetation. I counted at least 32 Hottentot Teal, but there were probably more. I hope to get out to Bahri next week with Marwa to see what is around.

Thursday, 5 June 2014

Another trip down to Sennar

Term finished on Monday at the school where I work and I headed straight down to Sennar, because I wanted to know if the Cinnamon Weavers would be breeding. The irrigation ditches were all dry and there was little sign of any active nesting, though a few males were starting to moult in some orange feathers and there was some activity and calling that could indicate the early stages of breeding behaviour. However, the majority of birds were still in flocks and in basic, non breeding plumage, so my guess is that nothing will begin until the rains set in.

I was pleased to catch my first Great Reed Warbler, especially after catching a Clamorous Reed Warbler a couple of months ago. I include a photo of the Clamorous below for comparison, as it really shows the different bill shapes. I was also pleased to catch my first Beautiful Sunbird and Grey-backed Camaroptera.

Great Reed Warbler, north of Sennar 4th June 2014

Clamorous Reed Warbler (for comparison), Bahri Sewage Ponds 4th April 2014

Beautiful Sunbird, north of Sennar 4th June 2014

Grey-backed Camaroptera, north of Sennar 4th June 2014

There were quite a few Collared Pratincoles flying around, with about 10 hanging out at a small muddy puddle at the edge of the village, including a couple of juveniles. This allowed me to get excellent views and to take some photos.

Adult Collared Pratincole, north of Sennar 4th June 2014

Juvenile Collared Pratincole, north of Sennar 4th June 2014

I will be away for a while, visiting El Salvador, Colombia and Spain where the birding should be quite spectacular. I will be back in August in time for the autumn migration.

Friday, 30 May 2014

The start of the wet season

Last week we had our first big downpour to herald the start of the wet season. I will head off soon on my summer break, and as always, I will return to find a widely different set of birds. When I arrive back in August there will no longer be any of the winter migrants, plus there will be a number of new arrivals. Last week Marwa and I saw our first Intermediate Egret, which is apparently mainly a wet season visitor. Today there were two birds present. Cattle Egrets started breeding a few weeks ago and there is one colony with perhaps a couple of hundred pairs. It seems that the Little Egrets and Squacco Herons are not going to leave and there are many now in breeding plumage, though we have yet to find any breeding colonies. Black-winged Stilts have never been reported breeding in Sudan, but there were lots around today and many appeared to be in pairs and flying around being very vocal as if involved in courtship.

Cattle Egret nesting, Bahri 30th May 2014

Black-winged Stilts, Bahri 30th May 2014

Storks always arrive over the wet season, with Abdim's being the most noticeable around Khartoum. We had our first of the year today. Openbills and Maribous are less common in the city, but will soon be found in big numbers a bit further south. Both species of glossy starling will soon be in Khartoum, plus other wet season arrivals such as Abyssinian Roller and African Pied Wagtail. Today we saw lots of Fulvous Whistling Ducks, which we have not seen at this site previously.

Abdim's Stork, Bahri 30th May 2014

Today I was a little surprised with the number of winter migrants still present, and I wonder if they will all leave. There were 5 Garganys, a Greater Flamingo, and several hundred terns, including Gull-billed, White-winged and Whiskered.

Vitelline Masked Weaver, Bahri 30th May 2014

As always, most of the morning was spent netting weavers. One nice capture was our first Vitelline Masked Weaver. I had wondered how easy it would be to notice among the Northern Masked Weavers, but it was pretty obvious with its brighter yellow underparts, reddish eye, all pale bill and plain coloured face (more reminiscent of female Cinnamon Weaver). In the hand it had a short bill (shorter than any of the Northern Masked I have captured). Another characteristic appears to be the wing structure, with the 2nd primary falling in length between the 5th and 6th primaries, whereas Northern Masked almost always falls between the 7th and 8th. It was a female in breeding condition with a brood patch, though I have not seen any signs of a colony around the site. Today we accessed a new area of the sewage works and found a large colony of Village Weavers. We have seen a small colony previously, but they seem to avoid nesting in the reeds and this colony was in a row of larger trees at the edge of the site. Northern Masked Weavers were nesting in the reeds below them.

Wednesday, 28 May 2014

Recent trips to Bahri

I haven't yet written up my last two trips to Bahri, on May 9th and 23rd, so I thought I would mention some of the sightings. Most of the effort was based around netting weavers, but we also caught a few other good birds. On the 9th we caught a couple of Red-billed Queleas, which is a species I rarely see this far north. They are a nightmare for farmers further south, where vast flocks of over a million individuals can destroy an entire crop, but they are still quite attractive birds.

Red-billed Quelea, Bahri Sewage Pools 9th May 2014

Another species I was pleased to finally catch was Ethiopian Swallow. We often see them flying around the reed beds, but they had yet to enter the net. This bird was caught on the 23rd.

Ethiopian Swallow, Bahri Sewage Pools 23rd May 2014

We saw a few other good birds around the sewage pools, mainly on the 23rd. Best was probably an Intermediate (or Yellow-billed) Egret, which I have only seen once before in Sudan. Nikolaus says that they move north during the rains, which probably explains my lack of sightings, as I am mostly out of the country during the peak of the rainy season. We also saw our first Green-backed Heron at the sight, which is surprising given how common they are on the river. Another good bird to see was a Painted Snipe, which was also our first at Bahri.

Intermediate Egret, Bahri Sewage Pools 23rd May 2014

The migration is still far from over. There were still lots of White-winged and Whiskered Terns around, plus a few waders. I was a little more surprised to see a White Wagtail, as I think of these as quite early migrants.