After yesterday’s sunny Spring weather we are waking up to snow this morning. Fortunately Pittsburgh missed the heavy snow and blizzard conditions to our east.
Last night Morela slept in the open at the Cathedral of Learning peregrine nest. You can tell that her feathers provide excellent insulation because several inches of snow did not melt right next to her body.
Immature red-tailed hawk focused on prey (photo by Chuck Tague)
10 March 2022
Despite distractions we humans can focus on just one thing if we want to. Birds of prey can do it, too, as seen in this video of a red-tailed hawk in Tompkins Square Park, New York. The hawk doesn’t care about squirrels or people or the ambulance but when he sees a rat …!
This ability to focus is called selective attention and was proven eight years ago in chickens. See this vintage article, Selective Attention in Chickens, with an amazing video to test your own selective attention.
Bonus test: After you see the video in the chicken article, try another test. (This test + answer lasts 3 minutes. The remaining 2 minutes show family & friends reactions.)
(photo from Wikimedia Commons; click on the caption to see the original. Videos embedded from YouTube)
We think of mallards (Anas platyrhynchos) as dabbling ducks that eat plant material and bread tossed by humans(*) but these common ducks are actually omnivorous and opportunistic. Their diet depends on time of year.
On migration and in winter mallards are basically vegetarian, eating seeds, acorns, aquatic vegetation, cereal crops, and in urban areas human-provided bread and birdseed.
Fortunately small bird consumption is quite unusual and unnecessary. Males and non-laying females eat only 37% animal matter in the breeding season while laying females consume 71.9% animal matter to meet their energy needs.
I saw a pair of mallards mating at Panther Hollow Lake last weekend so I know the breeding season has begun in Pittsburgh. Laying females will be bulking up on snails, insects and worms.
Meanwhile most mallards are still on migration to their breeding grounds. They will change their diet soon.
Snow cover in Schenley Park, 4 Feb 2022 (photo by Kate St. John)
8 March 2022
Pennsylvania has the highest rate of Lyme disease in the U.S. (CDC, 2019) so in early March the approach of tick season is always in the back of my mind. This winter we had some spates of bitter cold and some long runs of snow cover. Did winter suppress the ticks?
This month I learned from Keystone Trails Association that: “All the snow keeping our grounds covered throughout the cold winter months has only helped the tick population. Snow coverage acts as a giant quilt or insulator to keep the ticks warm under the leaf litter.”
Snow helps ticks survive the winter and we had a lot of it this year.
This month the ground is warming and black-legged ticks are getting active. All they need is unfrozen ground and an air temperature of 37°F to start moving out of the leaf litter. This spells danger for hikers, birders and especially for gardeners who handle all that leaf litter.
Before you go outdoors, take time to protect yourself as described in this vintage blog: Today is Spray Your Clothes Day. Did you find a tick on your body? Get it tested for Lyme disease at PA Tick Research Lab (https://www.ticklab.org/)
Spring is coming but so are the ticks. Be prepared.
The color combination helps them forage. While their black legs are probably ignored by their prey, the “yellow feet catch the eye of fish and other creatures, drawing them closer or stalling them so the egret can strike,” per Bird Watcher’s Digest.
Here are three of the snowy egret’s five foot-fishing techniques.
Foot stirring:
Foot probing: in slow motion.
Foot dragging: Dangling their feet in the water to make the fish rise up from the depths.
Sometimes an experiment doesn’t work as planned but the results are far better than expected.
Researchers wanted to track Australian magpies (Gymnorhina tibicen), a very social species that lives in groups of 2-12 individuals on permanent territories. Rather than use the typical long-lasting harness that requires recapturing the bird to collect the datapack, they designed a harness that would release when exposed to a magnet placed at a feeding station. Would the new harness design work? The first step was to try it on a few magpies and see.
Researchers led by Joel Crampton captured five magpies at Pacific Paradise, Queensland, banded them and fitted each one with a GPS harness. Then they followed the birds to see the harness release at the feeding station.
Each banded bird immediately tried to remove the harness but it was too well designed for that to work. Instead the unexpected occurred. Unbanded magpies came to the rescue.
On the day of trapping, one individual was observed attempting to remove its own tracker but was then approached and aided by another juvenile (without a tracker or coloured leg-band) once again pecking the harness part of the tracker. The tracker remained but, within the next 10 minutes, an adult female (also without a tracker or leg-band) proceeded to approach and successfully pecked the harness at various points such that the tracker came off the fitted juvenile within c. 10 minutes. This first Magpie that had been tagged had its GPS device removed within 1 h.
This happened over and over again until none of the banded birds had trackers. Here’s a video of the magpies helping each other.
This finding was unexpected but far better than the original experiment. It was the first time anyone had seen rescue behaviour among Australian magpies.
To our knowledge, this is the first study to report the conspecific removal of GPS trackers, and should be considered when planning future tracking studies especially on highly social species.
This week in Pittsburgh the weeping willows turned yellow for spring and male red-winged blackbirds came back to the marshes. At Homewood Cemetery the two combined when a red-winged blackbird called from a large willow. He’s the black dot at 9 or 10 o’clock (on the dial) in my photo.
Yellow willow tree + red-winged blackbird, Homewood Cemetery, 2 March 2022 (photo by Kate St. John)
The red-wings didn’t look so spiffy three weeks ago at Frick Park’s feeders, below. Now they are sharply black and red.
Red-winged blackbirds, 9 Feb (photo by Charity Kheshgi)
Over at Schenley Park the moss is greening up on the tufa bridges and purple “weed” leaves are looking hairy.
Tufa bridge has moss and purple basal leaves (photo by Kate St. John)
A closer look reveals the hairs may be tiny rootlets. Last summer I knew the name of this “weed” but I don’t remember it now. (Best guess via Stephen Tirone is hawkweed)
Are these tiny roots growing from the leaves? (photo by Kate St. John)
During the winter common grackles (Quiscalus quiscula) are mostly absent from Pennsylvania but in early March they head north to nest. Their return began this week with a trickle of solo birds on Tues 1 March which grew to small flocks of 5-7 on Thursday. Very soon large flocks will pass through on their way to Canada, taking over feeders and backyards as they did at Marcy Cunkelman’s in this 2005 photo.
Common grackles take over the yard, spring 2005 (photo by Marcy Cunkelman)
Even if you don’t see them you will hear the grackles announce themselves. Look to the treetops to see the males puff and “skrinnk!”
This week’s scouts are the early birds. More grackles are definitely on the way. Look at the difference in eBird reports between December-February and March-May!
eBird: Common grackle sightings, Dec-Feb past 10 years
eBird: Common grackle sightings, Mar-May past 10 years
Use eBird and your sightings will be added to the maps.
(photos from Marcy Cunkelman and Wikimedia Commons; distribution maps from eBird retrieved on 3 March 2022; click on the captions to see the originals)
Red-tailed hawk soaring, 2013 (photo by Cris Hamilton)
3 March 2022
In March red-tailed hawks conspicuously soar over western Pennsylvania. They take to the skies alone or in pairs to soar and dive and dangle talons. Sometimes they even scream.
What is all this soaring about? It’s a multi-purpose signal.
Soaring is part of hunting and migration of course, but in the spring it’s a way to claim territory, advertise availability to potential mates, and cement the pair bond.
What better way to tell other red-tailed hawks that a territory is already taken than by soaring above it? Adults do this alone and in pairs. Unwelcome red-tails are escorted away. “This is mine!”
A lone red-tail also soars to advertise for a mate saying, “This is mine and I need a mate to share it.” (I have no idea how they signal the difference between ‘stay away’ and ‘come here.’)
Before the female lays eggs pairs of red-tailed hawks soar to cement their pair bond.
Prenesting displays typically consist of both birds soaring in wide circles at high altitudes and the male performing maneuvers similar to the Sky-dance [in which the] bird dives steeply from high altitude, checks descent and shoots immediately upward at similarly steep angle.
After several series of dives and ascents, the male slowly approaches the female from above, extends his legs and touches or grasps her momentarily. Frequently, both birds dangle their legs during aerial maneuvers. The birds may grasp one another’s beak or interlock talons and spiral toward the ground. Piercing screams and quiet, raspy calls often accompany courtship flight displays.
