How High Can An Eagle Fly? Can A Raven Follow Him?

Bird Behavior, Birds of Prey, Crows & Ravens, Musings & News
A raven harasses V, the new male bald eagle at Hays, 18 Oct 2023 (photo by Jim McCollum)

24 October 2023

On 18 October while Jim McCollum was taking photos of the Hays bald eagles a raven showed up and began to harass the new male eagle, nicknamed “V.”

10/18 – The new fella went for a fly about and got jumped by a Raven. The Raven chased him all over the sky. This guy needs to work on his fighting skills.

— Jim McCollum -> 40 Acres a.k.a. Hays Woods Enthusiasts
A raven harasses V, the new male bald eagle at Hays, 18 Oct 2023 (photo by Jim McCollum)
A raven harasses V, the new male bald eagle at Hays, 18 Oct 2023 (photo by Jim McCollum)

Jim’s photos were shared to the 40 Acres a.k.a. Hays Woods Enthusiasts Facebook group where Dave Dutzik remembered a story about crows that piqued my interest.

A little tidbit I read recently. Crows will lite on eagles backs and peck at their necks. The eagles don’t fight back just soar higher and higher until for lack of oxygen the crow passes out and falls off the eagles back. I’m not sure about the validity but it’s a good story!

— Comment by Dave Dutzik at 40 acres Facebook group

Is it a true story? Let’s look into it.

At what altitude does lack of oxygen affect birds?

Birds are the champions of high altitude and can breed and exercise (fly) at altitudes that kill humans. Some species are so well adapted to high altitude that they fly as high as a jet, over the Himalayas where humans die without supplemental oxygen. Even our North American songbirds fly high …

Migrating birds in the Caribbean(*) are mostly observed around 10,000 feet, although some are found half and some twice that high. Generally long-distance migrants seem to start out at about 5,000 feet and then progressively climb to around 20,000 feet.

— Stanford Birds: How fast and high can birds fly

(*) Migrating birds in the Caribbean = warblers!

Is lack of oxygen the reason why the crow leaves the eagle? No. The crow leaves because the eagle is no longer a threat or because the crow is tired.

How high can a crow, a raven and a bald eagle fly?

So the better question is: How high can a raven fly? Can a bald eagle follow him?

For more information see High-altitude champions: birds that live and migrate at altitude and this vintage article.

As High As A Jet

(photos by Jim McCollum)

Duck Hollow Outing, Nov 12, 8:30a

Books & Events
Duck Hollow, 27 Oct 2022 (photo by Kate St. John)

Updated on 28 October 2023

Join me on Sunday 12 November 2023, 8:30am to 10:30am, for a bird and nature walk.

Meet at the Duck Hollow parking lot at the end of Old Browns Hill Road. Dress for the weather and wear comfortable walking shoes. Bring binoculars, field guides and a birding scope if you have them. (Always remember to visit the Events page before you come in case of changes or cancellations.)

We’ll walk the nearby paths seeking birds, interesting plants, and lingering insects. Migrating ducks may be resting on the river. Mallards will attract attention because they’re courting.

Mallards Come A’Courting

Occasionally a rare bird shows up, so keep your fingers crossed. I can tell you we will not see is this American avocet that stopped by Duck Hollow on 3 October but it was sure fun while it lasted.

American avocet at Duck Hollow, 3 Oct 2023 (video by Charity Kheshgi)

(photo by Kate St. John, video by Charity Kheshgi)

Look How He Can Move His Eyes!

Bird Anatomy, Songbirds
Great-tailed grackle (photo from Wikimedia Commons)

22 October 2023

The great-tailed grackle (Quiscalus mexicanus), a close relative of our common grackle, is so numerous and annoying in Austin, Texas in the winter that there are always news stories about them. This interview with a grackle researcher revealed a very cool fact about great-tailed grackles that probably applies to our grackles as well.

Great-tailed grackles can move their eyes independently to keep watch in two different directions at the same time! Check out the video below.

video from KUAN on YouTube

Look how he can move his eyes!

(credits are in the captions; click on the captions to see the originals)

Leaf Peeping and Patchy Frost Prediction

Climate Change, Phenology, Schenley Park, Trees
Bright red maple leaf near Phipps Conservatory, 16 October 2023 (photo by Kate St. John)

21 October 2023

Fall color’s peak in southwestern Pennsylvania used to be around the 12th of October but climate change has pushed it later, closer to the 21st, as you can see in the PA fall foliage prediction for 19-25 October.

PA fall color prediction for 19-25 Oct 2023 (map from PA DCNR)

This week I found bright leaves on red maple trees, at top, and yellow on buckeyes and hickories.

Schenley Park leaves are yellow and green on 16 October 2023 (photo by Kate St. John)
Yellow and orange maple leaves, Frick Park, 18 October 2023 (photo by Kate St. John)

Frick and Schenley are dominated by oaks whose color will peak in the next two weeks. Meanwhile their few red maples turned red from the top down and have lost their leaves in the same order. The maples are gorgeous up close but you can’t see them from a distance because the tops are bare.

The top of this red maple is almost bare, 16 October 2023 (photo by Kate St. John)

Tomorrow night the northwest wind will bring migrating birds overnight and patchy frost on Monday morning.

This is the week to go leaf peeping.

(credits are in the captions)

White Stork Transmitter Goes Roaming in Sudan

Migration, Water and Shore
White stork flock in Africa (photo from Wikimedia Commons)

20 October 2023

Most people who find discarded bird tracking technology don’t know what they’re looking at and even when they do they don’t usually repurpose it. But every once in a while a transmitter goes roaming.

White storks (Ciconia ciconia) that breed in Poland migrate to eastern and southern Africa for the winter. For some, their final destination is the Blue Nile River valley, circled in yellow on the map below.

White stork migration paths (map from Wikimedia Commons) Blue Nile Valley in Sudan is circled in yellow

In April 2017 a white stork in Poland, nicknamed Kajtka, was tagged with a transmitter containing a mobile SIM card.

SIM card T–Mobile Poland (image from Wikimedia Commons)

That autumn she flew to the Blue Nile River valley in Sudan where she became mysteriously inactive. Eventually she stopped moving altogether and had either died or the transmitter fell off. Researchers couldn’t figure out what happened until they got the phone bill.

Questions were raised when Kajtka lingered in the area for more than eight weeks, only roaming around 25 km [15 miles] in various directions.

In 2018, the mystery was solved when EcoLogic Group received a phone bill for 10,000 Polish zloty, the equivalent of £2,064 [$2,500]. Someone had picked up the tracker in Sudan and taken the opportunity to make 20 hours of phone calls using the SIM card.

— White Stork transmitter racks up massive phone bill

Fortunately for cash-starved bird research this sort of episode is rare.

If Kajtka had survived she would have joined her fellow white storks moving north in March, perhaps with a stopover in the Hula Valley shown below. Gorgeous!

video from The Wildlife Channel on YouTube

(credits are in the captions)

Feeling Thirsty?

Mammals, Musings & News
Rock pigeon taking a drink (photo from Wikimedia Commons)

19 October 2023

Do you feel thirsty when you wake up in the morning?

It turns out that as we exhale we also breath out water vapor, so during the hours of sleep we lose water. According to sleep specialist Dr. Michael Breus, the healthy solution is to drink a full glass of water in the morning before you drink coffee because caffeine is a diuretic.

We could avoid this by getting up in the middle of the night to drink water, but perhaps our bodies are compensating in another way …

Why Are We Thirsty Before We Sleep?

(credits are in the captions)

Hundreds of Grackles in the Trees

Bird Behavior, Migration
Common grackle flock moving through the trees, Patuxent Research Refuge, Nov 2021 (photo from Wikimedia Commons)

18 October 2023

This month a flock of 100 to 200 common grackles has been hanging out at Frick Park, chattering in the trees and swirling in a dense flock whenever they’re disturbed. This is typical fall behavior for grackles and blackbirds but I wondered why they picked the park.

According to Birds of the World, common grackles (Quiscalus quiscula) are not very territorial during the breeding season and drop all rivalry in fall and winter. On migration and at overwintering sites they prefer to roost and feed in huge flocks, sometimes mixed with other blackbirds and some robins.

Common grackles roost near plentiful food but they don’t require wild places. Urban roosts are often favored on tree-lined streets or in parks. Their fall roosts in New Jersey can contain 3,000-500,000 birds (of which grackles comprise 33%).

This flock at Patuxent in Maryland looks to be 100% grackles.

Common grackle flock on the ground at Patuxent Research Refuge, Nov 2021 (photo from Wikimedia Commons)
Common grackle flock starting to swirl up at Patuxent Research Refuge, Nov 2021 (photo from Wikimedia Commons)
Common grackle flock mostly flown away at Patuxent Research Refuge, Nov 2021 (photo from Wikimedia Commons)

Get To Know Nature in New Jersey shows what it’s like to be in the forest with hundreds of grackles.

video by Get To Know Nature on YouTube

The huge grackle flocks probably won’t stay in southwestern PA for the winter. By December they are further south, as shown on the eBird Dec-Feb map below.

Common grackle sightings, Dec-Feb, past 10 years (retrieved from eBird on 3 Mar 2022)

But for now we have hundreds of grackles in the trees.

(credits are in the captions; click on the captions to see the originals)

They Hear the Sound of Distant Waves

Bird Behavior, Water and Shore
Wandering albatross at the Tasman Sea (photo from Wikimedia Commons)

17 October 2023

Like elephants, albatrosses can hear low frequency sounds below our range of hearing, a skill that’s very useful for their lifestyle.

Wandering albatrosses (Diomedea exulans) spend their lives making incredibly long journeys over the ocean. They are known to circumnavigate the Southern Ocean three times in one year, a distance of more than 75,000 miles (120,000 km).

Range map of wandering albatross (map from Wikimedia Commons)

To do this with the least amount of effort, they have the longest wingspan of any living bird — 8 to 12 feet (2.5 to 3.66m) — and use the wind to glide as much as possible.

The best gliding happens at updrafts over the water and the best updrafts are caused by large waves. So how do wandering albatrosses find those large waves? They hear them from very far away, possibly 1,000 miles.

According to Science Magazine, “Big waves produce a very low frequency sound, below 20 hertz, that can travel thousands of kilometers, particularly when they collide with long distance swells, such as when storms develop.”

Would an albatross approach or avoid these waves in the Southern Ocean?

video from Monthly Fails on YouTube

To figure out how the birds choose where to go, Samantha Patrick of University of Liverpool and her team tagged 89 albatrosses with GPS trackers at their breeding grounds on Crozet Island near Antarctica. When the birds returned a year later to breed again, researchers retrieved the tags and analyzed the data.

Geophysicists on the team combined the biologger recordings with infrasound monitoring data from Kerguelen Island in the Southern Ocean to build “soundscape” maps on the birds’ journeys. …

During their long-distance flights, the birds tended to change course whenever they encountered a loud infrasound, the team reports. The infrasounds often indicate wave turbulence, even storms—though it’s not yet clear how the birds make use of this information. The infrasound clearly impacted the birds’ behavior, although the scientists couldn’t identify a clear pattern of whether they avoided or aimed for these low frequencies.

— Science Magazine: ‘Voice of the sea’ may help albatrosses catch the perfect wind

We don’t know yet if they avoid or approach turbulent areas but we know they hear them. More study needed!

Turbulent sea (photo from Wikimedia Commons)

Read more in Science Magazine: ‘Voice of the sea’ may help albatrosses catch the perfect wind.

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

ICYMI, There’s a New Male Bald Eagle at Hays

Birds of Prey
“V”, the new male bald eagle at Hays, 15 October 2023 (photo by Dana Nesiti, Eagles of Hays PA on Facebook)

16 October 2023

In case you missed it (ICYMI) there’s a new resident male bald eagle at Hays. The old male disappeared in early September. The new guy was obvious by late September.

“Dad” was one of the original eagle pair at Hays where nesting began in 2013. Pictured below in 2020 they fledged 20 youngsters in 10 years. The female was 4-5 years old when she arrived (14-15 years old now), but he was a full adult so no one knew his age. Bald eagles can live 30 years.

Hays bald eagle pair (female on left, “Dad” on the right) 8 Feb 2020 (photo by Dana Nesiti, Eagles of Hays PA on Facebook)

The newcomer, nicknamed V for visitor, became obvious as he set out to accomplish two important things in his early days of residence.

  • Vigorously defend his new territory against other males,
  • Court his new mate and cement their pair bond.
New male bald eagle, V, at Hays, 1 Oct 2023 (photo by Dana Nesiti, Eagles of Hays PA on Facebook)

This extra level of activity drew Hays eagle fans’ attention to his presence. Viewers have seen V chase away other bald eagles and mate with the Hays female.

This is typical behavior among new peregrines, too. Long time residents don’t work hard to show who’s boss, but the newcomers do. The first time it happened at the Cathedral of Learning peregrine nest it took me a while realize that new behavior was a clue. See how I figured out the first male switchover at Pitt in this vintage article: Who is he? New male at Pitt.

Meanwhile V and the Hays female will be busy getting to know each other as nesting season approaches in December.

New male bald eagle, V, flies past beautiful red maples at Hays, 15 Oct 2023 (photo by Dana Nesiti, Eagles of Hays PA on Facebook)

Check out the action in person at the Hays eagle viewing site and Dana Nesiti’s latest photos and news at Eagles of Hays PA on Facebook.

Read about the Hays eagle changeover in Mary Ann Thomas’ article in the Post-Gazette: With dad missing, Hays bald eagle finds a new, younger potential mate.

(photos by Dana Nesiti at Eagles of Hays PA on Facebook)

Why Does the Water Look Like Tea?

Trees, Water and Shore
Tannin stained water in Miners River, Michigan (photo from Wikimedia Commons)

15 October 2023

“Some tea with your river, Sir?” asks the caption on the satellite photo below where Rupert Bay meets James Bay in Quebec, Canada. James Bay’s incoming tide is pushing Rupert Bay’s tea-colored water upstream.

“Some tea with your river, Sir?” James Bay tidal water meets tannin-stained Rupert Bay, Quebec (NASA satellite image from Wikimedia Commons)
Tea-colored water is good.

In woodland and wetland settings, tea-colored water indicates that natural plant and water processes are occurring.

Frequently, water in streams and rivers becomes tea-colored from naturally occurring tannins, a chemical found in many plants around the world. The tannins can leach out of plants and plant debris and into groundwater, lakes, rivers, and streams. Although they can make the water more acidic, it’s important to note, tannins are not harmful to fish and wildlife.

This process occurs in many waterways that run through wooded areas and wetlands with high levels of plant mass and organic matter. Because there is always water flowing through these areas, tannins leach out of plants into the water, making it appear tea-colored.

— Mainelakes.org: Why is the Water Tea-colored?

Tannins leach from all kinds of plant debris, especially soaked bark, leaves and pine needles in the north woods. There are tannins in this magnified Woody Dicot Stem: Tannins in Early First Year Tilia. Its caption reads: “Many cells in the periderm, cortex and pith contain dark staining tannins.”

Woody Dicot Stem Tannins in Early First Year Tilia (photo from Wikimedia Commons)

Leaves made these tannin stains on pavement.

Leaf stains on concrete in Chermside (photo from Wikimedia Commons)

There are tea-colored creeks in northeastern Pennsylvania such as this one in Monroe County.

Tobyhanna Creek, Monroe County, PA (photo from Wikimedia Commons)

And there are some special lakes on Florida’s Panhandle coast where the tea-colored water flows into the Gulf of Mexico. This video describes the dune lakes of Walton County.

Tannins are OK to drink though they may not taste good. In fact, it’s the tannins in tea leaves that make the beverage tea-colored.

Orange water deposits are bad.

Bright orange deposits are bad, even when the water is clear. In western Pennsylvania the orange color comes from abandoned coal mine drainage. Here the outflow of a polluted culverted stream dumps into Chartiers Creek near Bridgeville. Yuk!

Inflow of abandoned mine drainage into Chartiers Creek near Bridgeville (photo by Kate St. John)

Blacklick Creek in Cambria County, PA is another example.

Blacklick Creek is orange from abandoned mine drainage, 2007 (photo by Kordite via Flickr Creative Commons license)

Don’t worry if the water is tea-colored.

Do worry if you see bright orange deposits. In western PA our orange creeks and streams are a case of Water Everywhere, But Not a Drop to Drink.

(credits are in the captions; click the links to see the originals)

p.s. GEOGRAPHY! Though far inland, James Bay is tidal because it is the southern tip of Hudson Bay which connects to the Atlantic Ocean. This watershed map shows Hudson Bay watershed in green. Note the tiny red circle I added for the location of Rupert Bay.

Primary drainage basins in Canada (map from Wikimedia Commons)