KENYABIRDSNET Abyssinian Scimitarbill nestbox.

On 20 October 2008, in my garden at Green Park, Naivasha, I erected a nestbox No. GP16 for White-bellied tits. It was a Gymnogene-proof design I had come up with in a previous study area, Lentolia farm, next to Crater Lake, where I lived for over 6 years. There White-bellieds were badly parasitized by Honeyguides and when the anti-Gymnogene boxes went up for Superb Starlings, the White-bellieds used them in some numbers. Lentolia was a 48 box project for many species, with about 38% occupancy.

The Green Park White-bellied box was totally ignored, as were 9 others there, of the so successful Lentolia design. But White-bellieds nested well at Green Park in a design rejected at Lentolia!

It therefore came as an exciting surprise when, on 11 June 2009, an Abyssinian Scimitarbill was calling by the box and another was in it, looking out a lot, for half an hour at least. The next day I added wood shavings to the bare box floor, and the Scimitarbills were not to be seen. A week later a Scimitarbill was calling in the approximate area of the box and 2 hours later one called by the box and maybe there was one in the box. The next day, 20 June, in the morning one was near the box making a “whistle” call, and that afternoon one arrived with its “chatter” call and went straight into the box.

Box visits with and without food were frequent from 21 June to 24 June when the pair sat together after one was called out of the box and fed by its mate, then both left together. 25 June both left together and 3 July both were near the box, and the next day one was in and was fed at the entrance hole. On 9 July a briefly seen Honeyguide, almost certainly Lesser, was seen to leave the box. The next day the pair came to the box calling; one went in and stayed in. All that day the pair came to the box together, and left together.

By studying all my notes I now estimated the young, if any, might be 6 days old. It had been frustrating to lose all the vital data one needs - date of first egg, date of last egg, date of hatching and so on. In a 200 box study in UK this data was collected all the time, but with Scimitarbills I was simply too apprehensive of desertion of nest to risk going to the box at all.

On 12 July it seemed the box clearly had young, so I risked climbing up. There were 3 young Scimitarbills which I judged as very roughly 8 days old, but could have been more. They weighed: 24g, 24g, and 20g. Two days later the adults’ box visits were most frequent and many times both had food. The female fell asleep outside the box! The young were photographed the day they were weighed. My next visit was 17 July, and more photos. They were photographed again 20 July. Sadly I had to go away 21-23 July. The morning of 24 July both adults visited the box but it seemed les than before. The next day I climbed up at 10.15 a.m. and the box was empty. The nest was damp with a strong smell so 5 hours later I cleaned it all out and added fresh wood shavings.

6 weeks later on 6 September one adult was at the box hole making tiny calls and the other was in the tree. Two days after that the adults with 2 young only were seen all over the garden. 10 September one was near the box making the calls that accompanied the breeding period. For the next 7 weeks the adults and young appeared infrequently.

Then on 26 October the 2 adults were at the box hole, good calls, and one went in and stayed a long time. 2 November both were at the box and left it together. I was surprised a second breeding might be close and also surprised the original box had been chosen again. On 7 November one flew to the box, then left. One was in the box, head out, food in beak, maybe just fed by the other one. It swallowed, then stayed with head out some time, and it may have remained in the box. On 11 November one was well into the box some time. Then what seemed to be the male was out and I wondered if it had emerged. If this bird was newly arrived, could it be that the other was now sitting? The next day there was one at the box with a good call. The other looked out some time.

Then 7 days later, on 19 November, there was an extraordinary turn of events.

I heard the pair calling a lot in thick bushes 88m from GP16 where I had erected a (same design) box, GP47 just for them on 11 June. So far as I know they have never been near it. Now I wondered whether all that I had seen at the original box for the past 24 days had been some sort of recce of that box, with a decision that, after all, it did not appeal. They soon left GP47 and went to another (same design again) GP65 erected for them 4 August 09 99m from GP16. Here I was very surprised to find one sitting below the box making the extra quiet noise (which I still cannot interpret) and one with the now familiar head out of hole pose. The one below the box was totally relaxed. I now wondered if the female had laid here.

I watched for some time and nothing changed, so I left quietly. On my way back to the house they flew over me, calling, and I found them back at GP16 again! One was calling endlessly and looking at the entrance hole. There was no response. After 10 minutes, out of the box came a Scimitarbill very suddenly, catching me off guard, with a white egg in its beak! It flew fast towards me and dropped the egg almost on my feet where it shattered on clean concrete, thus enabling me to gather what I could. Despite the endless small shell fragments I would think this was a small egg, maybe Lesser Honeyguide size. The contents were slight, probably not developing, and rotten. As I turned from gathering the bits, out of the box hole came a Scimitarbill, another white egg in its beak. I suspect but cannot be sure this egg was a little bigger. The bird flew the same route exactly and shot over the house roof. I ran outside to try to see it but it was gone. I looked a little for a broken egg - nothing. I went back to the box watching position and out of the box at once came a Scimitarbill with a definitely larger greenish egg in its beak. It followed the same route and vanished over the house. A really careful search of the area failed to reveal any broken shells at all, whether white or green. This was extremely disappointing.

Tragically therefore this astonishing event ends in unanswered questions. My experience at Lentolia showed various species of Honeyguide seem unlikely to lay unless confronted by the visual stimulus of an egg already in a box. If so why was the first white egg rotten? I climbed to the box, nest clean, tidy and no sign of shell. I assumed, wrongly perhaps, the green egg was the Scimitarbills’ first. If so, the small white egg should have been fresh. And what of the second white egg? Am I to assume a Lesser Honeyguide laid the first and maybe a Scaly-throated or even a Greater laid the second - both are here, both getting bees out of my other boxes often. It would make sense if a Scaly-throated or Greater was the second visitor, that it would puncture the Lesser egg and the Lesser would puncture the green egg if it was there.

Renewed interest in GP16 for a second clutch may have started 26 October. One Scimitarbill may have laid around 7 November. If so a 3 egg clutch would see the start of incubation maybe 10 November. By disaster day, 19 November, that would allow 9 days of incubation and if the Lesser egg had been there that long, and was punctured by a
Greater or Scaly-throated, that would allow it to be rotten when I scooped it up. But what of other Scimitarbill green eggs? Or were they removed when I was not looking? Clearly the checking of GP47 and GP65 by the Scimitarbills was, I suspect, induced by the knowledge that the breeding box was ruined by rotten eggs. But having removed them, does that not show intent to re-use, not to abandon GP16?

Two days after being near GP47 I checked the box. All tidy and clean. I did the same that day with GP65, also all tidy and clean. Scimitarbills have barely been seen or heard since the egg eviction day of 19 November. My hope was that with the box clear and clean, they would relay. Today, 5 days later, the birds are gone. I would hope for some interest in the box in the past 5 days, or even in the other 2 boxes that appealed before the egg eviction. I hope this is not a sad end to an otherwise exciting episode.

STOP PRESS! It is possible the Scimitarbills slept in GP16 last night!

Grahame Dangerfield

Hon Director

The Grahame Dangerfield Wildlife Trust, UK