Red-capped Robins in coastal Kenya

From: Neil & Liz Baker <tzbirdatlas@yahoo.co.uk>

Date: 2006-05-17 13:47

Subject: Red-capped Robins in coastal Kenya

Hi Colin

We have long suspected that these natalensis visitors to the coast have a SW origin rather than a simple southern one from the coast but of course have no idea how far they have travelled. I do recall a bird on Kifufu incorporating East Coast Akalat song phrases so perhaps some of your birds do not move far. We know they do not move in numbers through Mufindi and are not common as nocturnal migrants in Amani.

One day I'll get around to analysing our 1100 + ringing records.Terry, this would keep you busy for a few weeks !!!

Colin, what's your sample size now ? there should be a joint paper here somewhere.

Rains were VERY late this year and these are rains breeders. Moult is critical for these birds, they have to leave breeding grounds before they become too dry and burn. Adult males begin moult when females are on eggs.

It was always complicated in the Pugu Hills because we had a small resident breeding population there as well as passage birds and "winter" visitors.

1st arrivals would be adult males having completed moult on their breeding grounds, 2nd batch would have the 1st young of the year and remaining males, 3rd batch the last lot of imms and the 1st females, 4th batch would be the remaining females, the last of these would still be moulting inner secondaries such is their "desire" to migrate.

Now, it was never quite as simple as this of course but that's the general pattern.

In reality we could be taking about waves of birds from different sub populations.

So.. I would guess that your birds are late because the rains were late on the breeding grounds and they waited a few extra weeks before breeding. Sadly no one working in coastal Tanzania any longer.

I would be interested in the ratio of imms to adults this year and a comparison with previous years, this might give you a feel for breeding success this year.

Hope this helps

Neil

Colin Jackson <colin.jackson@arocha.org> wrote: ...following my email a few days ago asking where were all the Red-capped Robin
Chats I heard the first one during church on sunday in Malindi! Did a bit of env.
education and pointed it out to the congregation which amused and interested them
all!! Still haven't had them at Mwamba yet however - but understand one or two have
been recorded in Arabuko-Sokoke. It's very late for them, all the same and would be
interesting to know if any Tanzanians who get this (Neil?) have any idea why they may
have delayed so much.

Colin

-- -- -- -- -- -- -- -- -- -- - -- -- -- -- -- -- -- -- -- - -- -- --
Colin Jackson
Mwamba Bird Observatory & Field Study Centre,
A Rocha Kenya
PO Box 383
Watamu, 80202
Kenya

Tel: +254-(0)42-32023 (O), 32037 (H)
Mobile 0722-842366
eml: colin.jackson@arocha.org