On Finding Pellets

Bird Anatomy, Bird Behavior, Birds of Prey, Peregrines
Red-tailed hawk casting a pellet, 2018 (photo by Chad+Chris Saladin)

22 January 2023

This red-tailed hawk is not consuming the lump near his mouth. He’s casting a pellet of indigestible bones, fur and feathers that came up from his gizzard. Pellets are a normal by-product of digestion in birds of prey. If you find one, it can tell you what the bird was eating.

We always find pellets during annual maintenance at the Pitt peregrine nestbox including these three found during our 9 January visit (paperclip for scale). The pellets can be many months old.

Peregrine pellets from Cathedral of Learning nestbox, 9 Jan 2023 (photo by Kate St. John)

A closeup shows feathers and bones (no fur*) but is not very enlightening due to the pellet’s age. Fortunately I stored the pellets in a ziploc bag. After they thawed a small fly appeared inside the bag, hatched from eggs laid on the pellet in much warmer weather. Ewww!

Closeup of peregrine pellet (photo by Kate St. John)

I imagine the pellets came from Morela since the green perch is one of her favorite places to rest and digest.

Morela casting a pellet, 17 Dec 2021 (photo from the National Aviary snapshot camera at Univ of Pittsburgh)

Peregrine pellets are slightly longer than a paperclip. Some birds make much larger pellets.

On a hike at Audubon Greenway Conservation Area last Wednesday we found a surprisingly large pellet containing fur, bones and a big tooth. It was so large that we wondered if a bird could produce it. I didn’t pick it up but it looked as though it could span my palm.

Pellet found at Audubon Greenway, 18 Jan 2023 (photo by Kate St. John)
Alternate view of pellet found at Audubon Greenway, 18 Jan 2023 (photo by Kate St. John)

A Google search revealed that great horned owl pellets are 3 to 4 inches long, usually cylindrical and tightly compacted. This one may have opened up because it was soaked by heavy rain.

Great-horned owl clutching a feather (photo from Wikimedia Commons)

So what did the owl eat? Whose big tooth was that?

Learn more about owl pellets at The Owl Pages: Digestion in Owls.

* p.s. There is no fur in peregrine pellets because they don’t eat mammals, only birds.

(photos from Chad+Chris Saladin, Kate St. John, the National Aviary snapshot camera at Univ of Pittsburgh and Wikimedia Commons)

Up To The Rooftop

Bird Behavior, Peregrines
Ecco about to leap up to the roof at the Pitt peregrine nest, 20 Jan 2023

21 January 2023

Peregrine news at the Cathedral of Learning is pretty quiet lately.

Morela did not stop by the nest yesterday but Ecco visited a couple of times including a surprise approach to the snapshot camera.

His favorite way to leave was by jumping to the roof.

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

If You Think Gray Squirrels Are Cute …

Mammals
Gray squirrel (photo from Wikimedia Commons)

20 January 2023

Squirrels can be annoying at bird feeders but their expressions can be endearing.

If you think our eastern gray squirrels (Sciurus carolinensis) are cute you ought to see the native red squirrel of Europe (Sciurus vulgaris).

These native squirrels have been declining in the UK, Ireland, and Italy due to competition from eastern gray squirrels, imported from North America in the 1890s and spread by humans to new locations(*).

However, the native red squirrels are stabilizing in Scotland, in part because European pine martens (Martes martes) are increasing and they selectively prey on gray squirrels.

The European pine marten is pretty cute, too.

European pine marten (photo from Wikimedia Commons)

p.s. Gray (grey) squirrels are invasive in the UK but a 2016 study found that their populations are genetically distinct from their neighbors and they didn’t invade new places on their own. Humans spread them!

One of the worst offenders at spreading grey squirrels was the 11th Duke of Bedford, Herbrand Russell. Russell was involved in many successful animal conservation projects, but released and gifted many grey squirrels around the UK from his home at Woburn Park.

Russell also released populations [of grey squirrels] in Regent’s Park, likely creating the London epidemic of greys. 

— Imperial College London: Don’t blame grey squirrels: their British invasion had much more to do with us

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

Fermented Fruit Tastes Too Good

Mammals
Groundhog hanging onto a tree (photo from Wikimedia Commons)

19 January 2023

Fermented fruit tastes so good that wild animals large and small overindulge until they can barely walk.

Some, like this red squirrel, are puzzled by the odd feeling that overcomes them.

Groundhogs just keep going despite that wobbly feeling, not realizing that it’s hazardous to stand up. This particular groundhog got grouchy. He’s not a happy drunk.

And then there’s the story of a drunken moose who got stuck in a tree.

Why The Apple Tree Came Down

(photo from Wikimedia Commons)

The Forest Lives in Mortal Fear of Its Deer

Deer
Buck browsing a tree in Schenley Park, August 2022 (photo by Kate St. John)

18 January 2023

I now suspect that just as a deer herd lives in mortal fear of its wolves, so does a mountain live in mortal fear of its deer.

— Aldo Leopold, A Sand County Almanac: “Thinking Like A Mountain”

Aldo Leopold (1887-1948), quoted above, was a writer, philosopher, forester and conservationist. In the early 1900s he participated in a project to eradicate wolves from the American West. Back then it was thought that the absence of wolves would be great for our range cattle but no one considered what would happen to the landscape without the apex predator. Thirty years later Leopold wrote about it in A Sand County Almanac. We see the same results in Pennsylvania and in Pittsburgh’s parks today.

  • In the absence of hunters (wolves) the deer proliferated.
  • Deer still ate what they always ate, but the higher population consumed so much more.
  • The deer’s favorite food plants disappeared first; all new growth was consumed. The deer covered more ground and ate less favored plants.
  • After a couple of decades with constant browsing and so many plants missing, the landscape cannot regrow itself. The range failed within 20-30 years.

It’s not the rocks that are afraid of deer. It’s the forest that fears for its life because deer are its predators.

Doe and fawn browsing on a tree (photo from Wikimedia Commons)

When the deer population is in balance with the habitat, the forest is fine. When the population is too high the forest shows signs of distress on its way toward failure including browse lines and small bonsai-like trees, as seen in Schenley Park below.

Deer damage: Browseline in Schenley Park, Sept 2022 (photo by Kate St. John)
Bonsai-like deer damaged sapling, Schenley Park, Oct 2022 (photo by Kate St. John)

In Riverview Park deer overpopulation has encouraged the proliferation of invasive Asian jumping worms and led to a host of other problems including erosion, described by Mark Kramer in How One Park’s Ecosystem — and Maybe its Legacy — Is Eroding Away.

Amazingly, it all started with the decision to remove an apex predator. We humans are the reason why there are too many deer and, so far, we haven’t had the will to reduce their population to a sustainable level.

In the meantime the forest is afraid for its life.

(photos by Kate St. John and from Wikimedia Commons)

How Fast Is The Wind Blowing?

Weather & Sky
Oak leaf on an updraft in winter (photo by Marcy Cunkelman)

17 January 2023

We can’t see the wind but we can guess its speed by watching what it does to leaves and flags …

Wales national flag blowing in the wind (photo from Wikimedia Commons)

… and then using the wind speed chart from the National Weather Service (NWS) to make a guess. My guess for the above photos is a Gentle Breeze 8-12 mph or a Moderate Breeze 13-18 mph but it’s hard to tell.

Estimating Wind Speed (chart from the National Weather Service)

NOAA weather satellites don’t see the wind either but they can see the clouds moving in three layers.

  • High level clouds (cirrus) at 23,000 to 46,000 feet
  • Mid level clouds at a level of 10,000 to 23,000 feet
  • Low level clouds are below 10,000 feet

In their animations of satellite images we can almost see the wind but not its speed.

For instance, in this GOES East animation from last Thursday 12 January 2023 we can see the Atmospheric River pumping into California and a low pressure system moving up the Ohio Valley.

GOES EAST satellite, GeoColor timelapse images, 12 Jan 2023 6:56Z-10:51Z (animation from NOAA)

NOAA’s computers use the animated maps to calculate wind speed and direction. The result, called Derived Motion Winds, plots the wind height, direction and speed on a map.

Legend for Derived Motion Winds: Wind Height and Speed (NWS)

Here’s the same timelapse with Derived Motion Winds. Notice that the layers often don’t move in the same direction or at the same speed. You’ve felt this in an airplane as a “bump” when the plane rises or descends between conflicting layers.

GOES EAST CONUS, Derived Motion Winds 12 Jan 2023 (animation from NOAA)

You can “see” the wind anywhere in the Americas by choosing a satellite to view (list on the left) at the NOAA GOES Imagery Satellite Maps. Click on Derived Motion Winds if available.

To view the current GOES East satellite, pictured above, visit these links:

(photos from Marcy Cunkelman and Wikimedia, maps and animations from NOAA and the National Weather Service)

Lake Effect Clouds and the Classic Gleam at Sunset

Weather & Sky
The Gleam At Sunset, 14 Jan 2023 (photo by Kate St. John)

16 January 2023

Pittsburgh’s skies were oppressively gray on Saturday with thick Lake Effect Clouds but the forecast promised the clouds would break in early afternoon so I planned a walk in Schenley Park for 2:30pm. Hah!

By 3pm the clouds were still thick and gray and the revised forecast predicted they would break up in the 4 o’clock hour. Of course! We were about to get 15-30 minutes of full sun immediately followed by sunset at 5:15pm, a classic Gleam At Sunset. I timed my walk to arrive at Schenley’s golf course by 4:45pm.

My photos show what happened: the classic gleam, an unexpected sun pillar, and a beautiful red sky at sunset.

If you’ve never heard of Lake Effect Clouds and the Gleam At Sunset, find out more in last month’s article:

Why Do We Have a Gleam at Sunset?

(photos by Kate St. John)

Pitt Peregrine Highlights in 2022

Peregrines
Morela defends her chicks on Banding Day, 26 May 2022 (photo by Mike Drazdzinski at Univ of Pittsburgh)

15 January 2023

Pitt peregrines Morela and Ecco stay at the Cathedral of Learning year round but have not been active at their nest in this month’s gloomy weather. Next month real courtship will begin and so will the National Aviary’s Live Falconcam. It’s hard to believe the first egg of the year is only two months away.

To get in the mood for the 2023 nesting season here’s a slideshow of last year’s successful nest, a recap of highlights, and the Top 4 videos from the National Aviary falconcams.

Pitt Peregrine Highlights, 2022

  • The year began quietly with a bit of snow.
  • Ecco and Morela courted in February and March. Morela laid 5 eggs:
    • First egg: 3/18/2022, 08:31am
    • Second egg: 3/20/2022, 20:09 = 2.5 days later
    • Third egg: 3/23/2022, 04:40 = 2.4 days later … began incubation
    • Fourth egg: 3/26/2022, 06:32 = 3.1 days later
    • Fifth egg: 3/30/2022, 19:08 = 4.5 days later
  • Hatch Day: 3 of the 5 eggs hatched on 26 April. The 4th hatched on 3 May. The 5th never hatched.
  • The fourth chick hatched late and was weak from the start. It died on 7 May, four days after hatching.
  • The remaining chicks grew up into fully feathered juveniles through the end of May.
  • The chicks were banded on 26 May by Patti Barber of the PA Game Commission. This was the first time Morela and Ecco ever witnessed a banding. Morela was fierce (at top)!
  • When the chicks began ledge walking Yellow Girl fell in the gully. Red Boy came down to visit her. She jumped back up a couple of days later.
  • We had fun at Fledge Watch in early June.
  • Red Boy was found dead at the Allegheny County Airport on 28 June just 23 days after he fledged.
  • Both female chicks are loud! Yellow Girl demanded a handout and Silver Girl screeched all day on 6 July. Eventually they left home for good.
  • Ecco and Morela molt in July and August.
  • And they remain at Pitt year-round.

26 April 2022: Pitt Peregrine Chicks on Hatch Day, 4pm Feeding

28 May 2022: Ooops off the nest! One of the chicks falls in the gully.

31 May 2022: Back in the nest! Yellow Girl returns from the gully.

6 July 2022: Screeching all day … in July! Silver Girl demands a handout.

(slideshow photos by The National Aviary falconcam at Univ of Pittsburgh, Mike Drazdzinski at Univ of Pittsburgh, John English, Jeff Cieslak)

Seen This Week

Birds of Prey, Phenology, Trees, Weather & Sky
Sunrise, 11 Jan 2023 (photo by Kate St. John)

14 January 2023

The sunrise was gorgeous and cold last Wednesday when a group of us decided to walk at Jennings in Butler County. We saw few birds but there were ice heaves, buttress roots on an elm, and the seeds of old man’s beard (Clematis drummondii).

Ice heave at Jennings, Butler County 11 Jan 2023 (photo by Kate St. John)
Elm tree with buttress roots, Jennings, Butler County, 11 Jan 2023 (photo by Kate St. John)

When old man’s beard is in bloom it’s called virgin’s bower, transforming it from a young woman to an old man in a matter of months.

Seeds of Virgin’s bower, a.k.a. Old man’s beard, Jennings, Butler County, 11 Jan 2023 (photo by Kate St. John)

My friends who live north of the city have not seen many dark-eyed juncos at their feeders this winter, but juncos are definitely present at the Frick Park Environmental Education Center. Charity Kheshgi posted photos of our recent trip to Frick.

(bird photos by Charity Kheshgi embedded from Instagram, all other photos by Kate St. John)

Busy Beaver at Frick Park

Mammals
Beaver at Frick Park, Jan 2023 (photo by Malcolm Kurtz @woodlandpaths)

13 January 2023

This winter Frick Park has a returning resident though he or she may not be the same individual that used to live there.

In late December Malcolm Kurtz photographed and video’d a busy beaver in Nine Mile Run which he posted to his Instagram account @woodlandpaths. (page to the right below to see video)

Malcolm’s story was picked up by the Pittsburgh Park Rangers @pghparkrangers who named the beaver Castor — part of his scientific name Castor canadensis.

The Park Rangers’ story was picked up by CBS News at Park rangers watching over Castor, the new resident beaver at Frick Park. This beaver is a celebrity.

If you visit Frick Park’s Nine Mile Run valley, keep an eye out for Castor. Beavers are nocturnal but Castor is apparently a daytime camera hound.

(photo by Malcolm Kurtz @woodlandpaths via Instagram; posts are embedded)