Tuesday, February 2, 2016

Can Birds Predict Bad Weather?

I don't need to read the weather forecast to know if a storm is coming or not.  I just look to see who is gossiping around the bird feeder.

If it's just the usual suspects - the Chickadees, Dark-eyed Juncos, Goldfinches, and other small birds - I know we're good.  But when all the big guys and loners start showing up....

Hairy Woodpecker and Goldfinches
I know there's a storm brewing!

American Goldfinches
But how do birds know a storm is moving in?  Scientists have long thought that birds sense barometric pressure, and in 2013 Western University's Advanced Facility for Avian Research (AFAR) proved it by putting White-throated Sparrows in a hypobaric avian wind tunnel.  (Wind tunnel for birds?  I'm impressed!)  When scientists simulated an oncoming storm by dropping the air pressure before dawn, the birds would immediately start eating at first light instead of doing their normal morning preening.

But while birds being able to sense air pressure is really not a surprise, researchers suspect that birds may have another way of foretelling when bad storms are coming...

A couple of years ago researchers were testing whether or not the small Golden-winged Warbler could carry geolocators on their backs.  It turns out they could - and they provided some unexpected but extremely interesting data.

In April 2014, the Golden-winged Warblers had just flown from South America to their breeding grounds in the Tennessee mountains when an incredibly massive storm started brewing across the US, one that ending up spawning 84 tornadoes and killing 35 people.  Two days before the giant storm reached Tennessee - and while it was still over 500 miles (900 km) away - the birds turned around and fled 1,000 miles back down south to the Gulf of Florida and Cuba to wait out the storm before flying back up north.

Dark-eyed Junco
Realizing a giant storm was coming when it was still hundreds of miles away?  That's some impressive forecasting!  But researchers realized that the Warblers left even before there was any change in barometric pressure, wind speed, or anything else in Tennessee that would normally cause them to flee that early.  So how did the birds know a storm was coming so far ahead of time?

Eastern Bluebird
Scientists think that the birds must have been able to hear infrasound waves from the approaching storm.  Infrasound, sound where the wave frequency is so low that humans can't detect it, can carry over large distances, and this deep rumble made by far-off tornadoes might have tipped off the birds that something big was coming.

Northern Cardinal
Birds predicting oncoming storms by air pressure changes and infrasound make sense.
How about birds predicting earthquakes?

Downy Woodpecker
There have long been anecdotes about animals fleeing an area before an earthquake happens. There is now a hypothesis that some migrating birds could predict earthquakes because of their ability to detect shifts in magnetic fields.  Before an earthquake strikes, stressed rocks give off clouds of positive electric charge, which generate a magnetic field at the Earth's surface.  Do birds detect this, and could a change in migration patterns predict an earthquake?  Scientists with the ICARUS Initiative (short for International Cooperation for Animal Research Using Space) are hoping to find out.  They have started tracking migrating patterns of birds and bats by tagging them with ultralight, solar-powered transmitters, and disaster prediction is one of the things they are studying.  It will be interesting to see what they find.

Northern Flicker
Who knows?  Maybe someday instead of watching the Weather Channel for forecasts of impending doom, everyone will just watch the birds.

Saturday, January 23, 2016

The Gray Catbird

For some reason I didn't figure it out until just last summer, when Mr. Red House pointed and asked, "What is the gray bird over there that sounds like a cat?"

Gray Catbird
Ahhhh, so that's why it's called a Gray CATbird!

Gray Catbirds do indeed make a 'meow' that sounds impressively like an unhappy cat, but they can also mimic other birds and animals in their impressive song repertoire, much like their Mockingbird and Thrasher relatives.  Usually on the shy side, they often sing while hiding in shrubbery.

The Gray Catbird usually lives in semi-open areas with lots of dense, low growth, such as scrublands, woodland edges, overgrown farmland, shrubby swamps, and suburban gardens that have dense bushes and hedges.  They eat mainly insects and berries, but they will also visit suet feeders.

Catbirds are considered omnivores, and people have noticed them eating such varied and diverse things as cheese, bread, milk, mushrooms, doughnuts, boiled potatoes, fried fish, beef stew, peanuts, and beef soup!  Fruit and berries constitute some of their favorite foods, however, and a good way to attract them.  When I left out a feeder with grape jelly and oranges for some resident Orioles, it was the Gray Catbirds that came and ate it.

Catbirds build their nests in dense bushes, briar tangles, or thickets usually fairly low to the ground.  Because of this their main predators are snakes and, ironically, cats.  They are scrupulous in the cleanliness of their nest, immediately removing any excreta from the young, and they are very intolerant of any foreign eggs sneaked in by parasitic birds like Cowbirds.  Grey Catbirds have strong mothering instincts after they are born, however, and have been known to adopt and take care of the babies of other types of birds that have been orphaned.

baby Gray Catbird
Gray Catbirds are migratory birds, spending summers in the Eastern and middle part of North America and then spending their winters along the Gulf Coast, in Central America, and in the Caribbean. (Wouldn't that be nice?)  Some will reside year-round along the Atlantic coast even as far north as Massachusetts if there is a plentiful amount of food.

range map from the Cornell Lab of Ornithology
Like many songbirds, the Grey Catbird migrates at night, forming flocks of around 10 to 15 birds.  They migrate at night to avoid predators such as hawks and because they need less water flying through the cooler night sky.  A major threat to the Grey Catbird and other migrating songbirds, however, is collisions.  They often collide with vehicles and buildings during migration.  Night lights from buildings and communication towers confuse them, leading to more collisions.  In 1991 the city of Toronto launched the Fatal Light Awareness Program (FLAP) in order to address this issue, and since then organizations such as local Audubon Societies have started Lights Out campaigns, working with buildings in large cities to get them to turn off their lights at night during migration times.

baby Gray Catbird
All of our local Catbirds have migrated down South for the winter, which is probably good as the ones that overwinter in Massachusetts have a high mortality rate.  I enjoy seeing these beautiful birds every summer, though, and hearing its most unusual meowing call!

Happy bird-watching!
And for all those being affected by the large winter storms, stay safe out there!

Tuesday, January 12, 2016

The Black Carrot

Did you know that originally most carrots in cultivation were a deep purple, almost black, in color?

Mutant yellow and white varieties sprung up through the years, but it wasn't until the 17th century that orange carrot varieties were developed by Dutch farmers.

Purple carrots are now making a comeback, however, due to the interest in heirloom varieties.  Furthermore, purple carrots are extremely high in anthocyanins, which are powerful antioxidants.  It is these anthocyanins that give the vegetable its purple color (similar to blueberries, blackberries, and plums).  Breeders are now working with purple carrot strains to develop new cultivars with more of these antioxidant properties, and one of these new carrots is the Pusa Asita Black Carrot, which I grew in my garden this past summer.

Pusa Asita Black Carrot
This carrot was developed by Dr. Pritam Kalia, the head of the Division of Vegetable Science at the Indian Agricultural Research Institute in New Delhi.   Dr. Kalia has been working on developing varieties of vegetables that are both very nutrient-rich and also open pollinated, so that small farmers (who often cannot afford buying hybrid seed every year) can grow these and improve their nutrition.  The very nutritious Pusa Asita carrot is so rich with anthocyanins that it is practically black.

Much like beets, the juice of the Pusa Asita is a deep, staining, reddish purple, and would look beautiful in a juice or drink.  (In fact there is a traditional Indian fermented drink called Kanji that uses purple carrots to give it a beautiful wine color.)  I could see its color being more of a challenge when cooking it with other foods though.

So how did it do in my garden?  Well, honestly the germination rate of the seeds was extremely low.  I appreciate that Baker Creek Heirloom Seeds, the place where I purchased them from, recognized this and sent everyone another pack of seeds.  I only planted the first packet, though, as I ran out of room in my veggie garden, and ended up with just a mere handful of black carrots.

They are certainly beautiful carrots, but the taste?  I was unimpressed with the taste of mine and thought them rather bland.  However, this may be due to the fact that they were overrun by my tomatillo plants and got more shade (which can make them less sweet), or my watering or soil conditions were not as good (both of which can affect taste).  Either way, they were not nearly as sweet as my orange carrot varieties.  I've found online reviews of the taste of this carrot to be quite mixed.

Maybe it's just too nutritious and healthy for my taste?

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