Birds

[Brenda]

Ah, in that case I'm going to have to go with a "peep."

[cbobcat49]

Yesterday I saw an osprey perched in a dead tree along the shore of Quaker Lake at Allegany. I was probably only 50 yards away from it. It flew off before I could get a shot. argh!

[Brenda]

There have been several active Osprey nests along the perimeter of Montezuma on both Routes 89 and 5 & 20 this season but I haven't had the chance to stop and get any photos; not that they'd stay at the nest if I stopped anyway.

[Brenda]

Well, my sunflower field is looking pretty sad now but there are literally hundreds of small birds, many of which are Gold Finches, coming and going in waves to feed on the seeds. It is so cool to watch, but really tough to get a shot of. Speaking of shot (bird shot that is), yesterday when we were walking out there with the dogs they kicked up eight pheasants in the sunflowers! Pheasant season opens here on Oct. 20th. Yum.

[Matt]

Birds May See Earth's Magnetic Fields

Birds can travel the world without any of the gizmos that humans depend on, and a new study suggests how: Our feathered friends might "see" Earth's magnetic field.

While other mechanisms are thought to help birds navigate, including magnetically sensitive cells within their beaks, their brain regions responsible for vision are in full gear during magnetic navigation, researchers said.

"If you look into the brain of a bird during magnetic compass orientation, only the visual system is highly active," said study co-author Henrik Mouritsen, a biologist at the University of Oldenburg in Germany, noting that most migratory birds do so at night. "Other regions of the brain are not, so birds could use vision to 'see' Earth's magnetism and orient themselves."

Mouritsen and his colleagues' findings are detailed online in a recent issue of the journal PLoS ONE.

Magnetic chemistry

The researchers previously discovered molecules called cryptochromes, which change their chemistry in the presence of a magnetic field, in the retinas of migratory birds' eyes.

"When light hits these molecules, their chemistry changes and magnetism can influence them," Mouritsen said. The molecules might then affect light-sensing cells in the retina to create images, which would help the brain navigate during flight, he added.

A direct connection between the specialized cells and the region of the bird's brain active during magnetic orientation, however, had never been shown before.

Mouritsen and his team recently found such connections between the cryptochrome-holding retinal cells and the "cluster N" region of migratory birds' brains, located in part of the brain responsible for vision.

"Cluster N is highly active during magnetic field orientation at night, when migratory birds fly," he said, explaining that non-migratory birds don't seem to use it during night flight. "We can't see what birds see, obviously, but they may pick up some sort of shading in their vision at night to act as a compass."

No smoking gun

Mouritsen noted that while the work is exciting, it isn't direct proof that they can actually "see" Earth's magnetism during migratory flights at night.

"If we could listen in on the neural connections between the retinal cells and cluster N, and show they actually send magnetically-influenced signals to the brain," Mouritsen said, "then that would be really compelling evidence that they can see it."

Even if migratory birds can see Earth's magnetic field, he noted, plenty of mysteries remain to explain their uncanny navigation.

"Birds also use the sun and stars to navigate, but we're not certain how," Mouritsen said. "How do they compute all of this information and end up with a direction to fly in? There are so many steps in this process we simply don't know about."

http://www.livescience.com/animals/0709 ... etism.html

[Brenda]

Interesting article. Migration has always fascinated me. I've noticed an increase in the number of Blue Jays around the property over the past week, so I started looking into their migration patterns/habits. It turns out that they're quite a puzzle. This is an excerpt from Cornell's website; the link follows:

Cool Facts

Although the migration of Blue Jays is an obvious phenomenon, with thousands moving past some points along the coast, much about it remains a mystery. Some jays are present throughout the winter in all parts of the range. Which jays move and which stay put? Although young jays may be more likely to migrate than adults, many adults do migrate. Some individual jays may migrate south in one year, stay north the next winter, and then migrate south again the next year. Why do they migrate when they do?

http://www.birds.cornell.edu/AllAboutBi ... e_Jay.html

[Brenda]

I took advantage of the beautiful weather today and cleaned out all of my nest boxes (and evicted the mice that had been wintering in them). Now is the time to get those boxes ready for the season! The bluebirds will start scoping out nesting sites within the next 2 - 4 weeks!

[chris270]

Going to the Birdhouse (bird store) this weekend to see what they have, maybe get some nesting in the backyard this year.