Monthly Archives: December 2013

Iridescent

December 11, 2013Weather & SkyKate St. John

There are a lot of iridescent things in nature: birds, beetles, seashells, fish, minerals and clouds.

Yesterday, after a snowy start (and really bad traffic!) the wind swung around to the west and the sky cleared with a few fast-moving clouds. At lunchtime I looked up while standing in a building’s shadow and saw a thin, beautiful, iridescent cloud blowing past the sun.

Thin is important. Iridescence occurs when sunlight diffracts through a thin layer of water droplets (or ice crystals) of uniform size and orientation. The glowing colors are named for the Greek goddess Iris, the personification of rainbows.

Pittsburgh’s iridescent clouds aren’t nearly as cool as the nacreous clouds in Antarctica, but we don’t have the super-cold stratospheric temperatures that cause those clouds. For which I am grateful!

(photo by “not on your nelly” on Flickr, Creative Commons license. Click on the image to see the original)

Crows Stay Warm

December 10, 2013Crows & RavensKate St. John

Crows flying past Chevron Building at Univ of Pittsburgh (photo by Kate St. John)

10 December 2013

The crows are still roosting near the University of Pittsburgh’s Chevron building, puzzling the crow watchers and annoying pedestrians. In years past they always moved the roost to Polish Hill and the Strip District by the end of November. But not this year. We’re not sure why.

Maybe the lights are brighter or the location is warmer at Chevron. Warmth is important! It’s one reason why they roost together rather than alone.

All night long they perch on the branch tips of large bare trees and jostle to stay warm. The colder the night, the closer they huddle. Their social hierarchy determines who gets to be in the warmest central locations. But they constantly readjust. Peter Bell has heard them muttering and jostling when he leaves Chevron after dark.

For the next three nights low temperatures will be in the teens. Watch this PBS NATURE video and see how active the crows will be this week, changing places to stay warm.

(video commentary from PBS NATURE’s “A Murder of Crows“)

Snowy Owl Respect

December 9, 2013Beyond Bounds, Birds of PreyKate St. John

If you read PABIRDS you’ve seen this discussion and perhaps the video, but it’s well worth passing along.

This winter has quickly shaped up to be an “invasion” year for snowy owls. These big, beautiful birds are popping up in open spaces, on buildings and at shorelines across the northern United States. On the PABIRDS listserv alone, at least 33 snowies have been reported in Pennsylvania since December 1 — about half of them at Presque Isle State Park.

Snowy owls “invade” in the winter when they’ve had a hugely successful breeding season up north because of super-abundant lemmings last summer. Most of the visiting birds are young owls on their first trip away from home. They’ve come south to eat our abundant food and rest between meals. Studies have shown this is a good move on their part. Scott Wiedensaul points out that the vast majority eat well and return to the Arctic in spring. Of those that die, the leading cause of death is trauma, not starvation.

But they shouldn’t be harassed. Last Saturday there were seven snowy owls at Presque Isle as well as birders, photographers and owl enthusiasts. Most people kept a respectful distance but two photographers approached the owls and flushed them repeatedly even though observers warned them not to. This prompted Jerry McWilliams to write:

“Just a reminder to birders and photographers who are interested in observing or photographing the Snowy Owls. You should resist the urge, as we have all experienced, to try and approach too closely. The owl that visited my waterbird count this morning was very alert and did not remain in one spot for long. Between the Coyotes and enthusiastic humans, it is a challenge for these northern invaders to have a chance to rest and find a meal. Please come and enjoy them, but keep your distance and respect their needs.”

The disrespect is not limited to Pennsylvania. A similar discussion occurred on NJBIRDS about incidents in New Jersey.

Presque Isle Audubon and the state park are doing something about it. Presque Isle Audubon is organizing volunteers to alert visiting photographers and birders about owl etiquette as they enter the Gull Point Trail. State Park rangers (DCNR) will also be monitoring the situation.

If you see people harassing wildlife, speak up or report them to park rangers. If you would like to volunteer at the Gull Point Trail, click here for Presque Isle Audubon contact information.

A gentle reminder to respect the owls will go a long way.

(video by Cornell Lab of Ornithology, first published in 2010)

p.s. Click here to read an excellent explanation of wild bird reactions to humans — with a special emphasis on raptors and owls — by Julia Ecklar of the National Aviary.

Bitter And Sweet

December 8, 2013Plants & FungiKate St. John

Oriental Bittersweet fruit (photo by Dianne Machesney)

Poisonous to us but popular with birds, Oriental bittersweet (Celastrus orbiculatus) stands out in the landscape now that the leaves are off the trees.

This closeup of the berries shows why we like to use it in floral arrangements. Very beautiful.

But it’s aggressive. Imported in 1879 it grows more easily than American bittersweet (Celastrus scandens) with which it hybridizes. It occurs in nearly every state east of the Mississippi and is listed as invasive from Maine to North Carolina, from Wisconsin to Tennessee.

Watch for small flocks of birds feeding in the woods and you’ll find this vine. Click here to see what it looks like from a distance.

Bitter and sweet: an unruly competitor that’s food for birds.

(photo by Dianne Machesney)

46,600 Birds!

December 7, 2013Migration, Water and ShoreKate St. John

Yesterday Jerry McWilliams reported a single-day record of red-breasted mergansers at Presque Isle State Park: 46,600 birds!

Every fall Jerry conducts a daily waterbird count for several hours at Sunset Point. On Friday he and Roger Donn watched “huge flocks [of red-breasted mergansers] flying in off the lake and concentrating north of Gull Point, later moving west in groups of 100 to 300 birds for the entire morning.”

Where did these birds come from and where are they going? Red-breasted mergansers breed along the ocean and lake shores of tundra and boreal forests. They spend the winter at the coast from Canada to Mexico or at the Great Lakes. The birds Jerry is counting at Lake Erie have reached their final winter destination unless the lake freezes over. If that happens they’ll move on.

How is Jerry McWilliams sure of these numbers? For you and me the count would be quite a challenge but not for him. Jerry’s an expert at identifying and counting birds. He know the shapes of waterbirds, their flying style and habits. Color hardly matters. He uses a scope and estimates in groups. I watched him do it for a brief time last weekend when I visited Presque Isle. There were only 7,858 red-breasted mergansers that day and I thought that was a lot!

If you’re at Presque Isle looking for snowy owls, stop by Sunset Point and you can watch, too.

Read the count details for Friday December 6 are at this link on PABIRDS.

(photo of red-breasted mergansers in flight by lgooch on Flickr via Creative Commons License. Click on the image to see the original)

p.s. This is more than twice the number of crows we’ve ever counted in Pittsburgh in the winter.

Bird Equivalents

December 6, 2013Beyond Bounds, SongbirdsKate St. John

Tufted titmouse, Great tit (photos from Wikimedia Commons)

Here’s an interesting thought: Around the world there are birds with similar habitat and food requirements that are ecological equivalents to each other. Though they live on different continents they occupy similar niches. Sometimes they even look alike.

I was intrigued by this when I found a graphic on page 630 of Ornithology by Frank B. Gill showing three sets of equivalent birds from North America and Europe. Here they are:

Set #1. The tufted titmouse in North America (at left above) is an ecological equivalent to the great tit in Europe (at right).

All About Birds says the tufted titmouse prefers “eastern woodlands below 2,000 feet elevation, including deciduous and evergreen forests. Tufted titmice are also common visitors at feeders and can be found in backyards, parks, and orchards.”

Europe’s great tit prefers similar habitat. I wish our titmouse was as colorful.

Set #2. Our black-capped chickadee (at left below) is equivalent to Europe’s willow tit (at right).

Again according to All About Birds, “Black-capped chickadees may be found in any habitat that has trees or woody shrubs, from forests and woodlots to residential neighborhoods and parks, and sometimes weedy fields and cattail marshes. They frequently nest in birch or alder trees.”

In Europe, look for the willow tit in these habitats.

Black-capped chickadee, Willow tit (photos from Wikimedia Commons)

Set #3. The chestnut-backed chickadee of the Pacific Northwest (at left below) is equivalent to the coal tit in Europe (at right).

All About Birds says, “Chestnut-backed chickadees are found in dense coniferous and mixed coniferous forests of the Pacific Coast. You can also find them in shrubs, trees, and parks of cities, towns, and suburbs.”

The coal tit has similar habitat requirements in Europe and fills a wider niche in Ireland where competing marsh, willow and crested tits aren’t present.

Chestnut-backed chickadee, Coal tit (photos from Wikimedia Commons)

There are many more ecologically equivalent species. GrrlScientsist shows us Kenya’s ecological equivalent of the red-tailed hawk at this link.

Can you think of other bird equivalents?

(photos from Wikimedia Commons. Click on these links to see the originals: tufted titmouse, great tit, black-capped chickadee, willow tit, chestnut-backed chickadee, coal tit.
Today’s Tenth Page is inspired by page 630 of Ornithology by Frank B. Gill.)

Will You Be Underwater?

December 5, 2013Musings & NewsKate St. John

Earlier this year NOAA Coastal Services Center and NOAA’s climate.gov debuted an interactive mapping tool showing the effects of sea level rise on the US coast. I learned about the Sea Level Rise Viewer in the video above.

Though we’re in no danger in Pittsburgh my family lives within 10 miles of the coasts of Virginia, Maryland, Florida, Massachusetts and New York so I was particularly interested in those places. Some places near them, such as Norfolk, Virginia, are already experiencing nuisance flooding.

Using the tool I zoomed in on a favorite birding location: Merritt Island National Wildlife Refuge off Titusville, Florida.

One foot of sea level rise will put some of Merritt Island underwater and surround the access road from Titusville. Two feet will make it impossible to cross from Titusville and will bury Blackpoint Wildlife Drive. Here’s a screenshot of the two-foot rise.

Try the tool yourself.

Watch the video above to see how the Viewer works.
Click on this link for the Sea Level Rise Viewer.
Enter an address in the search box or double-click on the map to zoom in on your favorite place.
Now use the controls on the left panel to see the effect. Move the blue sliding bar up to make the water rise.

It’s amazing what a little rise in sea level can do. Some day Merritt Island will disappear.

(video and screenshots from NOAA Coastal Services Center)

In A Shrinking Bubble

December 4, 2013Beyond Bounds, Climate Change, Crows & RavensKate St. John

Ethiopian bush crow (photo from Wikimedia Commons) — Stresemann’s bush-crow (photo from Wikimedia Commons)

4 December 2013

As things stand now this intelligent, resourceful, omnivorous bird may go extinct in this century. Why? Because he lives in a shrinking bubble.

For a long time scientists could not figure out why Stresemann’s bush-crow (Zavattariornis stresemanni) lived in only one 6,000 square mile area of southern Ethiopia. He’s really smart, eats anything, and nests cooperatively but the bush-crow does not expand his range even though the habitat bordering his domain appears to be exactly the same.

His size and threatened lifestyle resemble that of the Florida scrub-jay whose range was 7,000 square miles but areas of suitable habitat much smaller. Scientists approached the bush-crow with the same tools they used on the scrub-jay and came up empty. The bush-crow’s bordering habitat was the same. Why didn’t the bush-crow use it?

Then in 2012 a team headed by Dr Paul Donald of the RSPB figured out that Stresemann’s bush-crow lives in a cool, dry climate bubble where the average temperature is less than 20^oC (68^oF). Outside his range it’s hotter and he won’t go there. Terrain and elevation created his zone but climate change is raising the temperature. The bush-crow’s bubble is shrinking and he is Endangered.

If his problem was caused by loss of habitat, as it is for the Florida scrub-jay, laws and habitat restoration could increase the bush-crow’s available land but climate change is a much thornier problem requiring international political will.

Right now there are about 9,000 breeding pairs of Stresemann’s bush-crows on earth. But for how long?

Click here to read about Stresemann’s bush-crow’s climate preference. Click here for his range map.

(photo from Wikimedia Commons. Click on the image to see the original)

Humans With Feathers

December 3, 2013Crows & RavensKate St. John

American crow (photo by John Beatty)

By now scientists are quite convinced that crows are smart but the physical layout of crows’ brains puzzled them for a long time. Our seat of intelligence, the “smart” part of the human brain, is small in crows. In fact it’s small in all birds. So where does all this braininess come from? A different part of the brain.

Tübingen neurobiologists Lena Veit and Professor Andreas Nieder proved this by having trained crows run memory tests on crow-accessible computers. The crows tapped the touchscreen with their beaks to select the answers.

The test was this: Here’s an image. Remember it. Now here are two images: one matches what you just saw, the other does not. In this battery of tests, pick the similar one. In the next round, pick the different one.

The crows not only mastered these tests but according to Science Daily when Veit and Nieder “observed neuronal activity in the nidopallium caudolaterale, one group of nerve cells responded exclusively when the crows had to choose the same image while another group of cells always responded when they were operating on the “different image” rule. By observing this cell activity, the researchers were often able to predict which rule the crow was following even before it made its choice. … This high level of concentration and mental flexibility is an effort even for humans.”

Wow.

Crows make and use tools. They remember faces. They remember a large number of feeding sites. They plan their social behavior around what others are doing.

“I thought we were going to the dump this morning,” says a crow to his buddy. “We aren’t? OK. Whatever. I’ll follow you.”

Humans with feathers.

The Battle Is On

December 2, 2013Birds of Prey, PeregrinesKate St. John

Peregrine falcon at Presque Isle State Park, 29 Nov 2013 (photo by Shawn Collins)

Ever since the first snowy owl showed up at Presque Isle State Park on November 23 Erie’s resident pair of peregrine falcons has been on the warpath. Peregrines hate owls and snowies are no exception. How dare an owl invade their territory!

On November 26 a second snowy arrived and perched near the first at Gull Point. On November 30, a third and darker owl came to Beach 6. The snowies like the banquet at the lake. They’re eating visiting waterfowl.

Snowy owl on the breakwater at Presque Isle State Park,29 Nov 2013 (photo by Shawn Collins)

Their arrival has kept the peregrines quite busy. Many observers have seen the peregrines attacking the owls.

One owl is annoying, two are worth shouting about. On Friday while Shawn Collins was on his way to Gull Point he heard a peregrine whining and warning at Beach 10. The peregrine was so upset and distracted that it remained perched and whining on a telephone pole while Shawn snapped several pictures.

Angry and swift, the peregrines teamed up to convince the owls to leave. Would it work?

The owls are bigger and know about large, powerful falcons. They come from the land of the gyrfalcon.

But the peregrines are persistent.

Who will win?

Snowyowl atPresque Isle State Park, 29 Nov 2013 (photo by Shawn Collins)

(photos by Shawn Collins)

Outside My Window

A Blog of Birds & Nature with Kate St. John