Author Topic: News: About Birds  (Read 19702 times)

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Offline The Peregrine Chick

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Re: News: About Birds
« Reply #38 on: August 11, 2013, 20:14 »
Thanks for your answer.  I guess we just have to hope it won't hurt the falcons or any other birds, what ever it was.

Looking back over my response I realized that I forgot to mention that the peregrines tend not to take prey birds that look/could be ill so chances are that even if they were to come across an ill/poisoned bird it would be unlikely that they would prey upon it.  And now that the story has made the news hopefully if is poison laid down whoever did it will stop rather than risk further publicity ... And yes hopefully all our birds will be safe from that and similar hazards!

Offline Moonstar

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Re: News: About Birds
« Reply #37 on: August 11, 2013, 15:43 »
Thanks for your answer.  I guess we just have to hope it won't hurt the falcons or any other birds, what ever it was.

Offline The Peregrine Chick

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Re: News: About Birds
« Reply #36 on: August 11, 2013, 13:18 »
As an addendum ...

There was a similar case with that I heard about from a raptor researcher doing some work in Argentina.  Swainsons Hawks were found dead and dying from where they had literally dropped from their perches on the branches in an avenue of trees beside a field that had just recently been sprayed with pesticide.  The pesticide was an organophosphate insecticide/pesticide (DDT is an organochlorine pesticide).  Swainsons tend to prey a lot on insects in the area (grasshoppers = lots of protein) and the hawks congregate in large groups.  Field was sprayed, grasshoppers ate sprayed crops, hawks ate grasshoppers then went to perch and started dying.  Hundreds of hawks that turned into thousands that year.  That particular type of organophosphate pesticide entered the market in 1964, Silent Spring came out in 1962 and DDT started to be banned in the late 1960s. 

Here's more:

Interestingly, there was a Swainsons mass death due to a hailstorm in Argentina:

Offline The Peregrine Chick

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Re: News: About Birds
« Reply #35 on: August 11, 2013, 13:17 »
If birds are poisoned, does it act quickly or are they able to fly around awhile before it kills them?
If they are able to fly around then would poisoned pigeons or any other poisoned birds harm the falcons if one of them happened to be a meal?  
Just wondering because of those black birds that were possibly poisoned by poison left out for the pigeons.

In case folks were on holidays, this is what Moonstar is referring to: Dead birds fall 'like raindrops' in Winnipeg's North End

To answer your question Moonstar, it would depend on the poison and how much ingested that would influence whether the birds could fly around.  But yes, they can fly after poisoning but whether they will and how far depends on the bird, poison, location, etc.  

If it was poisoning, what type of poison was used is nearly impossible to say without the necropsy results.  There are pigeon control products that don't kill the pigeons but do make them sick and they then move along.  Most folks who understand anything about pigeon control know that poisoning doesn't work, you need to exclude them from their roosting locations and exclusion techniques are primarily non-toxic and non-lethal.  Folks who don't know about pigeon control might do something like use rat poison or some such but pigeons aren't stupid and they won't eat it but other species might.  And sometimes folks get creative and use products that are for other purposes but they use it because it is on hand.  

Having said that, there have been intentional poisoning of pest bird species such as this one in South Dakota a couple of years ago

Now grackles are omnivores - they eat pretty much anything: crops, bugs, eggs/chicks, garbage, you name it, that's why they are so successful. (All About Birds - Common Grackle) And they are gregarious so they could have all been affected at the same source and that is a lot of ground to cover.  So it could have been intentional, unintentional or accidental - once they have performed toxicological testing, they should have a better idea of what it could have been.

I know that pest control firms in Winnipeg avoid using poisons wherever possible so they don't have indirect/incidental deaths.  And they know about the peregrines.  There used to be poison on rooftops all the time when the project first began and so far as I can recall, we have never had an incidental death on record.  We have had poisoning but it was accidental - for example when a chick ingested some oil.

Hope this answered your question ...

Online Jazzerkins

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Re: News: About Birds
« Reply #34 on: August 11, 2013, 10:09 »
Good question moonstar.  I was wondering the same thing as were these birds died is not all that far from the Radisson or HSC.

Offline Moonstar

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Re: News: About Birds
« Reply #33 on: August 11, 2013, 07:17 »
If birds are poisoned, does it act quickly or are they able to fly around awhile before it kills them?
If they are able to fly around then would poisoned pigeons or any other poisoned birds harm the falcons if one of them happened to be a meal? 
Just wondering because of those black birds that were possibly poisoned by poison left out for the pigeons.

Online Jazzerkins

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Re: News: About Birds
« Reply #32 on: July 30, 2013, 20:47 »
Good article.  I cannot understand why some people would collect what are basically egg shells and by doing so, destroy the possible life that was in them, especially from endangered birds.  ???

Offline Kinderchick

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Re: News: About Birds
« Reply #31 on: July 30, 2013, 20:00 »
Very interesting reading, indeed. As TPC has said, a long article, but well worth the read.

Offline The Peregrine Chick

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Re: News: About Birds
« Reply #30 on: July 30, 2013, 13:20 »
this is a bit longer than most our news stories but well worth the read ...

Operation Easter: the hunt for illegal egg collectors
by Julian Rubinstein
The New Yorker / July 22, 2013


http://www.newyorker.com/reporting/2013/07/22/130722fa_fact_rubinstein?currentPage=all

Offline irenekl

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Re: News: About Birds
« Reply #29 on: June 19, 2013, 00:59 »
Such a sweet story kinderchick, I love that!!

Offline Kinderchick

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Re: News: About Birds
« Reply #28 on: June 18, 2013, 13:04 »
"Noah and the Bunnies" - A great story about a homing pigeon/rock dove at a rehab centre...  8)

http://www.wildroserescueranch.com/noahandthebunnies.html

Offline The Peregrine Chick

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Re: News: About Birds
« Reply #27 on: February 11, 2013, 12:39 »
How Birds Got Their UV Vision
Tanya Lewis, LiveScience - 11 Feb 2013

If optimists see the world through rose-colored lenses, some birds see it through ultraviolet ones. Avians have evolved ultraviolet vision quite a few times in history, a new study finds.

Birds depend on their color vision for selecting mates, hunting or foraging for food, and spotting predators. Until recently, ultraviolet vision was thought to have arisen as a one-time development in birds. But a new DNA analysis of 40 bird species, reported Feb. 11 in the journal BMC Evolutionary Biology, shows the shift between violet (shorter wavelengths on the electromagnetic spectrum) and ultraviolet vision has occurred at least 14 times.

"Birds see color in a different way from humans," study co-author Anders Ödeen, an animal ecologist at Uppsala University in Sweden, told LiveScience. Human eyes have three different color receptors, or cones, that are sensitive to light of different wavelengths and mix together to reveal all the colors we see. Birds, by contrast, have four cones, so "they see potentially more colors than humans do," Ödeen said.

Birds themselves are split into two groups based on the color of light (wavelength) that their cones detect most acutely. Scientists define them as violet-sensitive or ultraviolet-sensitive, and the two groups don't overlap, according to Ödeen. Birds of each group would see the same objects as different hues.

The specialization of color vision has its advantages. For instance, a bird with ultraviolet-sensitive vision might have spectacularly bright plumage in order to impress a female, but that same plumage might appear dull to predator birds that see only in the violet range.

Feathery findings

The study researchers sequenced the DNA from the 40 species of birds, from the cockatiel to the whitebearded manakin. They extracted DNA from the bases of feather quills, blood, muscle or other tissue. From that DNA, the scientists reconstructed the proteins that make up the light-sensitive pigments in the birds' eyes. Differences in the DNA revealed which birds were sensitive to violet light versus ultraviolet.

"That change is very simple, apparently," Ödeen said. "It just takes a single mutation" in the DNA sequence. While that change may seem insignificant, it can be compared to the difference humans see between red and green.

The researchers mapped the birds' evolutionary relationships using data from their study and others. The color mutation that made bird lineages with violet vision evolve to see in ultraviolet and vice versa occurred at 14 different times in their map, and probably even more among all birds, Ödeen noted.

Why the bird lineages switched their color sensitivity — essentially species of a certain branch on the family tree evolved to have the reverse type of vision — is still something of a mystery. The ability to attract mates while still evading predators could be one reason. Ultraviolet light might also provide higher contrast that makes finding food easier. Other factors are environmental — open spaces have more UV light than do forests, for example. Ultimately, the color sensitivity may be a result of other changes that affect the amount of ultraviolet light the birds' eyes receive.

It seems the evolution of color vision in birds is much less black and white than was once thought.



Check out the story online (including a quiz) here - http://www.livescience.com/26994-how-birds-uv-vision.html

Offline Kinderchick

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Re: News: About Birds
« Reply #26 on: February 10, 2013, 18:00 »
Incredible! :o What great genes she must have!

Offline MayShowers

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Re: News: About Birds
« Reply #25 on: February 07, 2013, 12:30 »
Absolutely amazing!

Offline bcbird

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Re: News: About Birds
« Reply #24 on: February 06, 2013, 22:52 »
Thanks, TPC.  

It's great to see this story continue.