They Eat Poison Ivy

Bird Behavior, Songbirds
Yellow-rumped warbler eating poison ivy berries (photo by Cris Hamilton)

22 October 2020

When you see a bird eating white berries from a hairy vine you might not realize it’s eating poison ivy. Birds are blissfully immune to the urushiol in poison ivy sap that gives us humans a nasty rash.

By late October poison ivy (Toxicodendron radicans) doesn’t look like the plant we’ve been avoiding all summer. The leaves are red or missing, the vine is exposed, and bunches of white berries hang from the branches. It’s easy for migrating yellow-rumped warblers (Setophaga coronata) to find the food they’re so fond of.

Yellow-rumped warbler eating poison ivy berries (photo by Cris Hamilton)

Resident birds such as downy and pileated woodpeckers munch on the berries all winter.

Downy woodpecker eating poison ivy berries (photo from Flickr account Dendrioca cerulea via Creative Commons license)
Pileated woodpecker eating poison ivy berries (photo from Flickr by Jen Goellnitz, Creative Commons license)

It makes me feel itchy to think of it!

p.s. Deer eat poison ivy, too.

(photos by Cris Hamilton and from Flickr via Creative Commons licensing by Dendrioca cerulea and Jen Goellnitz; click on the captions to see the originals in Flickr)

Schenley Park Outing, Oct 25

Books & Events, Schenley Park
White-throated sparrow reaches for a berry (photo from Wikimedia Commons)

Back in March I canceled all my 2020 outings because of COVID-19. The disease has not disappeared — in fact it’s resurging now in the U.S. and Allegheny County — but we’ve learned more about how it spreads and the relative safety of being outdoors. Today I’m announcing my first and probably last outing of 2020 (winter is coming).

Next Sunday morning, 25 October 2020, I will hold an outing in Schenley Park with restrictions to keep us safe.

  • Participation will be limited. To join you must “register” by leaving a comment on this blog post (not in Facebook). I will respond via email & tell you where and when to meet.
  • Everyone must wear a mask that covers their nose and mouth.
  • We’ll social distance as we walk.

We’re sure to see fruits, seeds and fallen leaves. Birds may be few but there will certainly be acorns, chipmunks and blue jays. Will we find a white-throated sparrow? I hope so.

To prepare: WEAR A MASK. Dress for the weather and wear comfortable walking shoes. Bring binoculars and field guides if you have them.

Visit my Events page before you come in case of changes or cancellations.

Dolphins Are Polite In Conversation

Mammals, Water and Shore
Bottlenose dolphin (photo from Wikimedia Commons)

20 October 2020

We know that dolphins are intelligent and that their whistles and clicks are a form of communication. It was only a matter of time before we figured out part of what they’re saying. For instance …

Dolphins say their own names using a “signature” whistle.

In 2016 we learned that mother dolphins name their babies by speaking a new signature whistle — the baby’s name — a few days before the calf is born and for two weeks after birth. The calf learns the name its mother gave it and later names itself with its own signature whistle.

Bottlenose dolphins, mother and baby (photo from Wikimedia Commons)

Four years ago the Dolphins Plus research institute in Florida proved that dolphins talk to each other when cooperating on a task. Though they didn’t call this “speech,” the Karadag Nature Reserve in Ukraine later showed that dolphins speak in complete sentences of at least five words.

What amazed me most about that discovery is that each dolphin waited for the other one to complete its speech before responding. I’m impressed that dolphins are polite in conversation.

In my family we all talk at the same time. Though we don’t always hear what the other person is saying, we don’t get offended if someone speaks while we speak. It was many years before I realized the behavior is impolite and I still struggle to wait and listen.

I should take a lesson from dolphins.

Bottlenose dolphin (photo from Wikimedia Commons)

(photos from Wikimedia Commons; click on the captions to see the originals)

Airborne For 10 Months Of The Year

Bird Behavior, Migration
Common swifts from Crossley ID Guide for Great Britain and Ireland (image from Wikimedia Commons)

In eastern North America our chimney swifts (Chaetura pelagica) land every evening to roost in chimneys. In Eurasia and Africa the common swift (Apus apus) stays airborne for 10 months of the year!

No one knew this until Lund University in Sweden attached geolocator tracking devices to common swifts in 2015. When the swifts returned from their winter range in Africa the Swedes recaptured the tagged birds and found that most had not landed since they left!

Since common swifts spend so much time in the air and can live for 20 years an individual swift may fly 3 million miles in his lifetime. Wow.

(image from Wikimedia Commons; click on the caption to see the original)

If This Was A Normal Year

Peregrines
Morela at the Pitt peregrine nest, 17 Oct 2020 (snapshot from the National Aviary falconcam)

18 October 2020

In a normal year there’s practically no activity at the Cathedral of Learning peregrine nest from July until the next January so it’s safe for me to ignore the nestcam snapshots while the streaming falconcam is off. But not this year.

This fall the two male rivals, Terzo and Ecco, continue to vie for the site in their typical non-violent manner. In other words, no one gets hurt and no one wins. Meanwhile Morela waits at the nest and greets whoever shows up. On 5 October Ecco made several appearances with Morela. On 6 October Terzo showed up alone.

Eleven days later, 16 and 17 October, Terzo made several appearances with Morela and Ecco showed up alone.

Friday 16 October: Morela and Terzo bowed in the morning and evening. At midday Ecco showed up alone and shouted for Morela to come to him. She never did.

Terzo and Morela at Pitt peregrine nest, 16 Oct 2020, 10:26am
Ecco shouts for Morela to join him. She didn’t, 16 Oct 2020, 11:53am
Terzo and Morela at Pitt peregrine nest, 16 Oct 2020, 4:23pm

Saturday 17 October: Morela hung out at the nest (top photo) and Terzo showed up alone. No sign of Ecco.

Terzo at Pitt peregrine nest, 17 Oct 2020, 6:05pm

If this was a normal year I’d expect the two males to settle the question soon, leaving just one of them to rule the Cathedral of Learning.

This is not a normal year in more ways than one.

(photos from the National Aviary snapshot camera at Univ of Pittsburgh)

Fall Color at Its Best

Phenology, Schenley Park
Sassafras leaves, Schenley Park, 10 Oct 2020 (photo by Kate St. John)

This week was a spectacular time for fall color in the Pittsburgh area. Schenley Park was especially beautiful as brilliant red sugar maples gave way to subtler sassafras, ash, buckeye and sweet gum.


Ash leaves, Schenley Park, 12 Oct 2020 (photo by Kate St. John)
Subtle violet tinge of ash leaves, Schenley Park, 12 Oct 2020 (photo by Kate St. John)
Buckeye leaves, Schenley Park, 10 Oct 2020 (photo by Kate St. John)
Sweet gum leaves, Schenley Park, 10 Oct 2020 (photo by Kate St. John)

By Tuesday the brightest red leaves had fallen to the ground. The forest shifted to yellow.

Fallen maple leaves, Schenley Park, 13 Oct 2020 (photo by Kate St. John)
Bridle Trail, Schenley Park, 13 Oct 2020 (photo by Kate St. John)
Falloon Trail near Westinghouse Shelter, Schenley Park, 10 Oct 2020 (photo by Kate St. John)
Lower Panther Hollow Trail, Schenley Park, 12 Oct 2020 (photo by Kate St. John)

(photos by Kate St. John)

How To Find Dinosaur Teeth

Bird Anatomy, Musings & News
Closeup of Tyrannosaurus rex , a theropod from the Cretaceous of South Dakota, Field Museum, Chicago (photo from Wikimedia Commons)

How do paleontologists find fossils? Better yet, how do they find small bits such as tiny dinosaur teeth?

Saurornitholestes and his teeth (screenshot from video)

In Wyoming they get help from ants.

In the video below Australian paleontologist Mikael Siversson (“Birds are dinosaurs”) describes a trip he and a colleague made to Wyoming dinosaur country in the late 1990s. The video starts with a picture of the Badlands as he begins to tell the story. Watch for four minutes — or longer if you want to learn about dinosaur teeth. It involves bathtubs.

(photo from Wikimedia Commons, screenshot from video; click on the captions to see the originals)

p.s. The toothy mouth pictured at top is the reconstructed skull of a Tyrannosaurus rex, a theropod ancestor of birds. Did birds have teeth? You bet!

Watch For Amazing Flocks This Fall

Bird Behavior, Migration, Schenley Park
Migrating flock of common grackles take over the trees (photo from Wikimedia Commons)

Now that the breeding season is over birds have gathered for migration and the winter.

Early this week 50 common grackles leapfrogged over the trees and forest floor as they searched for food and bathed in Panther Hollow Run. (This photo gives you an idea of their abundance.)

Cedar waxwing numbers peaked in Schenley Park in early October when they devoured most of the porcelain berries. They’ll spend the winter further south, for instance in Memphis, Tennessee where this photo was taken.

Cedar waxwing flock feeding on the ground (photo from Wikimedia Commons)

Pine siskins were everywhere a couple of days ago. Are they still visiting your feeders? Where will they head next?

Pine siskin flock in Minnesota (photo from Wikimedia Commons)

Starlings numbers are building in Pittsburgh as northern visitors arrive. Soon there will be thousands.

European starlings overhead, Maryland (photo by Mr. T in DC via Flickr Creative Commons license)

Crow numbers are building too. Last weekend I counted 2,400 but more arrived last night. Eventually the flock will look like this video from 2011. Where will they roost? Stay tuned.

Watch for spectacular flocks this fall. Let me know what you see.

(photos from Wikimedia Commons and Mr. T in DC, video by Sharon Leadbitter. Click the captions to see the originals)

Up to 55 mph Non-Stop For 11 Days

Alaska, Migration, Water and Shore
Bar-tailed godwit (photo from Wikimedia Commons)

14 October 2020

Yesterday the news broke that a bar-tailed godwit fitted with a satellite tracking tag had flown non-stop over the Pacific Ocean from Alaska to New Zealand in 11 days. During his 7,500 mile trip he reached speeds of up to 55 miles an hour. He’s an amazing bird from an amazing subspecies.

Bar-tailed godwits (Limosa lapponica) breed in Scandinavia, Siberia and Alaska and spend the winter at shores from Europe to Africa, from southern Asia to New Zealand. Most travel over or near land (see map) but the Alaskan subspecies, Limosa lapponica baueri, flies down the center of the Pacific Ocean to New Zealand. According to Wikipedia, this subspecies makes “the longest known non-stop flight of any bird and the longest journey of any animal without feeding.”

Late last year the Pukorokoro Miranda Shorebird Centre in New Zealand satellite-tagged 20 bar-tailed godwits to find out where and when they go. Tracked by the Global Flyway Network, godwit 4BBRW left Alaska on 16 September and landed in New Zealand on 27 September.

Find out more and see his route at The Guardian link below.

Route of bar-tailed godwit 4BBRW, Sep 2020 (map from Global Flyway Network, embedded from The Guardian)

(photos from Wikimedia Commons; 4BBRW map embedded from The Guardian article, complete route from Wikimedia Commons; click on the captions to see the originals)

p.s. Next spring he’ll fatten up to return to Alaska on one of these red routes.

Limosa lapponica baueri migration routes (image from Wikimedia Commons)

And he’ll look a lot fancier in breeding plumage.

Bar-tailed godwit in New Zealand in June, breeding plumage (photo from Wikimedia Commons)

Meet The Ancestors

Musings & News
  • Song sparrow with ancestor (photo by Frank Izaguirre)

We’ve known for a while that birds are descended from dinosaurs. In fact, paleontologist Mikael Siversson says, “Not only are birds descended from dinosaurs, but in fact birds are dinosaurs. They are highly specialized surviving dinosaurs.”

Of course modern birds have never met their long lost relatives so last Sunday Frank Izaguirre tweeted “A gift I recently gave myself was to put some dinos in the yard to facilitate this meeting of the ancestors.” They met below the bird feeder (photos above).

Bird-dinosaurs were lucky to survive the K-T extinction event that ended the Age of the Dinosaurs. Mammals survived, too, and in the absence of large dinosaur predators they took over.

Later Frank tweeted …

(photos by Frank Izaguirre)