Tell me something I don't know! About Birds (1 Viewer)

[Andy Hurley]

Indeed, that was something new! Particularly that one hypothesis is that they can hear (or feel) infra-sound.

Had to look that one up Stuart. I take that is the same as VLF in old money?

 

[Nutcracker]

Indeed, that was something new! Particularly that one hypothesis is that they can hear (or feel) infra-sound.

It's one of those mind-blowing news items that birds pull off every so often, like the Bar-tailed Godwits flying non-stop from Alaska to New Zealand, the 90,000-km-a-year Arctic Terns, the Nutcrackers that can remember exactly where they hid 100,000 pine nuts last autumn (and still find them under a metre of snow!), and that birds can see magnetic fields (and hence also compass directions) as 'colours'. Things that just totally beggar belief, and would have been dismissed as fantasy just a few years ago.

 

[Cristina_H]

Flying in a V-formation help birds take advantage of the extra lift provided by the upwash of air from the bird in front of them.

https://www.youtube.com/watch?v=eKSZtbSEmwg

The video as a whole is pretty incredible news.

 

[stuartvine]

Had to look that one up Stuart. I take that is the same as VLF in old money?

Yep, as long as VLF is Very LOW Frequency - the sort of noise hefalumps make

 

[chris butterworth]

The only bird that can fly backards is the Humming bird .......

Red-tailed Tropicbirds also fly backwards, as part of their display flight.

 

[grobble]

I will ask a question instead.

Does anyone know why some birds, notably birds of prey, have gaps in theit feathers at the wing tips when in flight?

 

[Nutcracker]

It improves air flow across the wingtip, by decreasing turbulence. I don't know the exact mechanics.

 

[njlarsen]

I read an interesting piece in an American Airlines magazine last time I was flying. It was about winglets, those little areas at the end of each wing that are bent upwards and how much fuel they saved. If you look at a photo of a vulture in flight, you can often see that each of those primaries that do not overlap at the end of the wing bends up like a whole series of small winglets. My theory is therefore that those two things have something in common.

Niels

 

[njlarsen]

Red-tailed Tropicbirds also fly backwards, as part of their display flight.

Chris, can they do that in all situations or only when the head wind is strong enough to drive them backwards?

Niels

 

[dantheman]

Had the notion that the physical structure of feathers allows for less wind resistance on the upstroke as the feathers can tilt/allow air between them, whereas they are closed together on the down, much as humans do when swimming with closed fingers.

(Related, and may have some bearing.)

 

[wolfbirder]

I was amazed to read that 25% of Black Swans exhibit homosexual behaviour by paring up with fellow males once eggs are laid. Similar behaviour is exhibited in 10-15% of Western Gull populations, and up to 19% of Mallards exhibit male on male sex.

 

[Nutcracker]

and up to 19% of Mallards exhibit male on male sex.

These two on my local patch this spring were pretty devoted to each other :t:

 

[davercox]

I was amazed to read that 25% of Black Swans exhibit homosexual behaviour by paring up with fellow males once eggs are laid.

According to the wildfowl warden, all the (pinioned) Black Swans remaining on Dawlish brook are males. Didn't stop two of them building a nest last month, opposite the appropriately-named Gay's Creamery

 

[Andy Hurley]

Yep, as long as VLF is Very LOW Frequency - the sort of noise hefalumps make

Thanks Stuart, oh, yes its what I meant

 

[stuartvine]

By the way, I hope everybody has purchased, borrowed or stolen a copy of Tim Birkenhead's "Bird Sense", well worth a read.

 

[dandsblair]

Bird of Paradise feathers

I think most people are aware that Bird of Paradise feathers are among the longest and strongest in the bird kingdom. However did you know the King of Saxony Bird of Paradise has two up to 60cm long feathers that stick out from the head and have up to 40 or 50 enamel like flags.
These feathers when waved from the head on a display perch attract females, (although this young male only 13 flags on each feather was unsuccessful when we saw the display) but when the feathers are molted are then used by Archbold and other Bowerbirds to attract their mates before Highland Tribesmen collect them from used Bowers to adorn their head dresses.
http://www.birdforum.net/gallery/showphoto.php/photo/419555/ppuser/107571

 

[gweller]

How about this one.... Robins make use of a phenomenon called quantum entanglement to navigate. Interesting program from the BBC about it here https://www.youtube.com/watch?v=brAbjq1lweM

Cheers!
Gary

 

[chris butterworth]

Chris, can they do that in all situations or only when the head wind is strong enough to drive them backwards?

Niels

AFAIK the backward flying is an integral part of display regardless of the wind. The best views I've had were looking down on a pair in the Papeno'o valley, Tahiti when the air was fairly still.

 

[Cypselurus92]

Not sure if this is appropriate for the forum, but I did stumble across it one day, and I found it quite interesting..

http://news.nationalgeographic.com.au/news/2001/10/1023_corkscrewduck_2.html

A male Lake Duck (a relative of the Ruddy) may use its very long corkscrew genitalia to lasso unwilling females to force copulation..

 

[ovenbird43]

Not sure if this is appropriate for the forum, but I did stumble across it one day, and I found it quite interesting..

http://news.nationalgeographic.com.au/news/2001/10/1023_corkscrewduck_2.html

A male Lake Duck (a relative of the Ruddy) may use its very long corkscrew genitalia to lasso unwilling females to force copulation..

And in some species the vagina is also corkscrew-shaped but in the opposite direction as the penis, as a countermeasure against insemination during forced copulation. http://scienceblogs.com/notrocketsc...ses-and-corkscrew-vaginas-the-sexual-battles/