Thursday, February 24, 2011

Nectarivory

During the recent holiday to Egypt I saw many, many Chiffchaffs. This was not entirely surprising as unlike the closely related Willow Warbler which winters mainly in West Africa south of the Sahara, many Chiffchaffs also cross the Sahara and concentrate in Senegal, while many others remain in Mediterranean North Africa; also at least 3 often inseparable races breed in the Middle East, collybita (includes brevirostris), menzbieri and probably abietinus and at least two others visit. So at any time, and especially during winter, spring and autumn the origins of Chiffchaffs and race of each individual in Egypt is hard to determine. There is no doubt I heard and saw our familiar collybita, with both the typical “hweet” call and occasional snatches of “chiff-chaff, chiff-chaff”. I also heard the “squeaky chicken” call frequently and on a couple of occasions, snatches of the fast, melodious song of Siberian Chiffchaff tristis, totally unlike the Chiffchaff song I know and more like a demented Dunnock.

Chiffchaff

Any day soon spring Chiffchaffs arrive in the UK and ringers know that in spring they may catch recently arrived Chiffchaffs carrying pollen residues on their bills. This pollen was deposited by the feeding strategy known as nectarivory, or birds indulging in sipping nectar from flowering plants during which flowering pollen is left on the bird itself, mainly around the base of the bill, the part of the bird most closely in contact with the flower. Nectarivory is also known to occur in some species of bats.

Chiffchaff

In Hurghada I witnessed many Chiffchaffs taking nectar, at times the liquid being visibly sipped as birds stuck their heads deep into the flowers, and upon the bird withdrawing from the flower, drops of the nectar spilling from their bill. A particular favourite plant of the Chiffchaffs was a flowering Mexican Saguara cactus shown in the photographs below. In a few of the pictures, by zooming up it is possible to see the nectar drops around the bill.

Chiffchaff on Cactus

Saguara catus

Chiffchaff on Cactus flower

Chiffchaff

Chiffchaff

Chiffchaff

Chiffchaff

In the two week trip I had one sighting only of Nile Valley Sunbird, another bird that takes nectar. In view of the tremendous number of flowering plants in Makadi Bay my single sighting was a little disappointing. The biggest numbers of Nile Valley Sunbirds do occur much further south than Hurghada, but in the last 100 years, and almost certainly helped by the building of tourist resorts, the species has spread from the southernmost parts of the Red Sea and up to the Cairo area where it breeds. I didn’t get to Cairo to look for more sunbirds so settled for my one brief encounter and a couple of distant shots.

Nile Valley Sunbird

1 comment:

marga said...

Maravillosos, los adoré :)

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