Truly African Birds Found in South Africa

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Klipspringer
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Re: Truly African Birds Found in South Africa

Post by Klipspringer »

^Q^ ^Q^ ^Q^


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Re: Truly African Birds Found in South Africa

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Defence
Many organisms use chemicals in a variety of ways to defend themselves against predators. They do it by being malodorous, tasting really bad, or actually being poisonous. Skunks do it. Butterflies do it. Frogs do it. Fish do it. But birds?

The way of the woodhoopoes
All birds have a small preen gland situated above the tail, at the base of the spine. In most birds the gland secretes a variety of fatty acids, oils and other organic compounds, which the birds spread on their feathers during preening.
Such preening has two widely recognised functions: in much the same way as regularly used wood or leather needs oiling, the oils of the gland are considered essential to the maintenance of good feather condition; the second function may be for fungicidal, bactericidal or other hygienic purposes.
Woodhoopoes seem to have found a third and unique use for this gland. Their preen gland is capable of producing a scent so strong that experienced researchers can tell how recently a roost cavity was used, based only on the lingering odour. Further, the secretion remains detectable for several hours on the hands of those who have handled birds (and is extremely unpleasant to taste). In short, woodhoopoes smell bad!
Yet more compelling, albeit circumstantial, evidence for chemical defence comes from woodhoopoe behaviour. When disturbed at their roost cavities, woodhoopoes do something rather unusual. Normally, birds will try to defend themselves with their bills, and woodhoopoes certainly have bills long enough for us to suppose they might do the same. Curiously, they face away from a threat. Not only do they turn tail, but they also expose their preen gland. Typically, the emission of a drop of their extremely pungent secretion accompanies this behaviour. This response to threat seems to be designed to maximise the effect of a deterrent odour.

http://www.fitzpatrick.uct.ac.za/sites/ ... 955-59.pdf


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Lisbeth
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Re: Truly African Birds Found in South Africa

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Repeating myself: "Nature is incredible! ^Q^ ^Q^ "


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Re: Truly African Birds Found in South Africa

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O:V ^Q^ ^Q^


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nan
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Re: Truly African Birds Found in South Africa

Post by nan »

Klipspringer wrote: Tue Dec 08, 2020 11:39 pm ^Q^ ^Q^ ^Q^
thank you Klipspringer to believe me 0/0
I followed this bird several days (I'm always 4-5-6 days in each camp) in a row, to see it was not foraging for insects \O


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Klipspringer
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Re: Truly African Birds Found in South Africa

Post by Klipspringer »

nan wrote: Mon Dec 07, 2020 11:14 pm a cavity like that :-)
Green Wood-Hoopoe


Image
nan wrote: Tue Dec 08, 2020 11:26 pm here you are -O-
several days in a row this one is 14.11.2009 (the other was 13.11.2009)

Image
This is possibly a breeding site. Looking at the bill, this bird is a female.

Wood-hoopoes sleep communally in tree cavities at night, entering 45 minutes before it gets dark and leaving just after sunrise. Large flocks may roost in two or three holes for the night. They use several holes in their territory and change roosting sites.

The nesting hole is separate from the group’s communal roosting site. Only the female of the breeding pair incubates the eggs but all members of the group, including the breeding male, bring her food, and also bring food to the nest after the eggs have hatched. The female will also leave the nest during incubation and go foraging for herself.
Interestingly, in the first few weeks, the female begs just like a juvenile for food brought to the nest by others. After she receives it she then feeds it to the babies. As the babies get older, the non-breeding helpers compete to feed the nestlings directly, evading the female.

All members of the group protect the nest and mob any potential predators.

All members of the group communicate with the young by cackling, and they even take turns preening the youngsters before they fledge. After the babies have left the nest, all group adults look after the juveniles and lead them to their own roosting cavity and settle them in for the night, before departing to the adults’ roosting site.

0/* nan, what do you think? Do we have an incubating female on her nest site here?
:twisted: Qualified comments by all readers are of course welcome.


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Lisbeth
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Re: Truly African Birds Found in South Africa

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Please describe "qualified" O** lol


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Re: Truly African Birds Found in South Africa

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Posting more than a smiley and contributing to the interpretation of the photos we have :twisted:


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nan
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Re: Truly African Birds Found in South Africa

Post by nan »

Klipspringer wrote: Thu Dec 10, 2020 11:44 am
nan wrote: Mon Dec 07, 2020 11:14 pm a cavity like that :-)

Green Wood-Hoopoe

0/* nan, what do you think? Do we have an incubating female on her nest site here?
Yes Klipspringer I think you are right, because I observed this bird for a long time, without trying to approche to not disturb, it was so fascinating for me :yes:


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Lisbeth
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Re: Truly African Birds Found in South Africa

Post by Lisbeth »

Nan's photos clearly show how a photo can lie; in the second the trunk looks much bigger, but not the bird :-?


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