Purple dead nettle (Lamium purpureum) has been blooming in southwestern Pennsylvania since early spring.
This Eurasian member of the Mint family attracts attention because it often grows in dense colonies where the plants stand together in reddish purple stacks of leaves and flowers. Some patches stand eight inches tall.
All the Mints have bilaterally symmetrical(*) flowers but the shape of this one makes the plant easy to identify — a pinkish purple hood with a unique two-lipped landing pad for bees.
Closeup of purple dead nettle flower (photo by Kate St. John)
Until I snapped a closeup in good light I had never seen the hairs that give it the nettle name. Reminiscent of stinging nettle the hairs don’t sting; they’re “dead.” Notice that the flowers have tiny hairs, too.
Purple dead nettle has a long blooming period so we’ll see it flowering until next winter. Look for the plants now, though, because their best display occurs this month.
(photos by Kate St. John)
(*) “Bilaterally symmetrical” means it matches side-to-side, like our faces. A harder word for the same concept among flowers is zygomorphic.
Dori with her first chick at the Gulf Tower, 19 April 2017, 3:27pm (snapshot from the National Aviary falconcam)
Since yesterday we’ve been having a joyous time as we watch five peregrine eggs hatch at the Gulf Tower (shown above). Dori and Louie are excellent parents who’ve raised 27 young in Downtown Pittsburgh. We’re looking forward to a happy healthy season at this nest.
Meanwhile across town, the Cathedral of Learning peregrine eggs are due to hatch soon … but you might not want to watch.
4 eggs at the Cathedral of Learning, 19 April 2017 (snapshot from the National Aviary falconcam)
Hope and Terzo’s eggs are due to hatch this Sunday April 23 (give or take a day or two) but Hope shocked us last year by killing and eating two of her four chicks as they hatched. This type of behavior is very rare and upsets nearly everyone who sees it.
We don’t know if Hope will repeat the behavior this year but my word to the wise is this:
Caution! Don’t watch the eggs hatch at the Cathedral of Learning if it upsets you to see a mother kill her young. Again, we don’t know if Hope will do this, but she might.
p.s. Yesterday some of you were confused between the Gulf Tower and Cathedral of Learning nests. Here’s an easy way to tell the difference.
The Gulf Tower camera view always has a window ledge on the right side of the image (see yellow area).
Comparison camera view at Gulf. Notice the window ledge on the right.
The Cathedral of Learning camera view always has a green perch at the bottom right.
Cathedral of Learning nest view. Notice the green perch at the bottom right corner.
(snapshots for the National Aviary falconcams at Gulf Tower and University of Pittsburgh)
p.s. Don’t confuse this mother peregrine at the Gulf Tower with Hope at the Cathedral of Learning nest. Dori is an excellent mother and has never killed her young. Hope, the female peregrine at Pitt, killed and ate two of her chicks last year.
Sugar maple flowers (wind pollinated), 15 April 2017, Schenley Park (photo by Kate St. John)
Are you sneezing yet?
It’s a busy week for trees in southwestern Pennsylvania as they open flowers and unfurl new leaves.
Redbud flowers fully open (insect pollinated), 15 April 2017 (photo by Kate St. John)
In Schenley Park the trees are flowering everywhere, from insect pollinated redbuds (pink above) to wind pollinated sugar maples (yellow at top) and hophornbeams (below).
Hophornbeam catkins (wind pollinated) 15 April 2017 (photo by Kate St. John)
Last weekend it was so dry that pollen coated my car and made my throat and eyes itch … and this was before the oaks had bloomed! (Pollen note: Both oaks and pines are wind pollinated. Southwestern PA has an oak-hickory forest with few pines.)
Other busy trees include the bursting buds of hawthorns and hickories. …
Hawthorn buds bursting, 15 April 2017 (photo by Kate St. John)Bitternut hickory bud is opening, 15 April 2017 (photo by Kate St. John)
… and new leaves on yellow buckeyes.
Yellow buckeye shows off its leaves, 15 April 2017, Schenley Park (photo by Kate St. John)
The city is a heat island so Schenley Park’s trees are ahead of the surrounding area. Our red oak buds burst yesterday so you can expect several busy weeks ahead for trees in southwestern Pennsylvania.
Chimney swifts (Chaetura pelagica) are due this week. We’re likely to hear their chittering sound before we see them hawking insects overhead. Though they look like cigars with wings (above) they’re actually related to hummingbirds! In the western U.S. watch for the similar Vaux’s swift (Chaetura vauxi).
Two of this week’s predicted migrants were in Schenley Park yesterday.
A blue headed vireo (Vireo solitarius) sang his slurred, sweet song next to Bartlett Playground (click here to hear). Bobby Greene’s photo shows off this vireo’s blue-gray head, white spectacles, and the yellow-green wash on his flanks that makes him hard to see among new leaves.
Warbler season is here with yellow-rumped warblers back in town and one or two sightings of black-throated green, prairie, yellow, black-and-white and a common yellowthroat in our area.
Hays bald eagle carrying nesting material, March 2015 (photo by Dana Nesiti)
Watch raptors on your bike!
On 29 April 2017, the Steel Valley Trail Council (SVTC) and Three Rivers Birding Club (3RBC) will hold a bicycle ride along “Raptor Row” of the Great Allegheny Passage Trail. It’s a celebration of the raptors who nested along the Monongahela River last spring.
Travel up and down river from Hays to Duquesne or McKeesport to see bald eagles, a great-horned owl (ARL will have a live owl on site), red-tailed hawks, ospreys and kestrels.
When: Saturday, April 29 Where: Waterfront Town Center, 270 Bridge Street behind Starbucks. What: A bicycle ride on the Great Allegheny Passage Trail from Hays to Duquesne (13.5-mile round trip) or to McKeesport (this 18-mile round trip includes kestrels). Three Rivers Birding Club members will be stationed at the raptor nest sites, many with scopes for close viewing of nests and any raptors that may be present. How: Costs are at the link below. VIP option has a bird guide ride with you! If you don’t have a bike you can rent one on site from Waterfront Bike Rentals.
Click here for details and more about the raptors:
Mild weather during the Cherry Blossom Festival in Washington, D.C., 2006 (photo by Andrew Bossi via Wikimedia Commons)
Ah, the mild days of spring! You know the days I’m talking about, the ones that are perfect for birding, gardening, picnics and outdoor weddings. The not-too-hot, not-too-cold, not-too-wet weather that makes you happy to be outdoors.
Unfortunately Pittsburgh will have fewer of them in the future. That’s what scientists from NOAA and Princeton University found out when they studied how the warming climate will affect our pleasant weather.
The loss has begun already though you may not have noticed it. For the last 35 years (1980-2015) earth’s climate has been converting 1 nice day per year into something unpleasant, mostly in Brazil, Africa and the Middle East.
By the end of the century the change will affect us. The world will lose 10 mild days out of 74 but the loss won’t be evenly distributed. The tropics will lose even more mild days while Canada, Maine and the Rockies can look forward to a pleasant future.
Here’s what our future looks like on the map. Notice how the eastern U.S. is light orange indicating a net loss.
Map showing the change in the annual number of mild days across the globe comparing 1986-2005 to 2081-2100. Areas of blue have increased in mild days. Areas of brown see a decline. (Van der Wiel/ NOAA/ Princeton)
That map shows the annual change but in fact it will vary by season. For instance, Pittsburgh will gain some mild days in the fall (maybe 15) but lose more than that in the summer (25 to 50). June-to-August will be hot!
Changes in the number of mild weather days by season for 2090 (maps from Van der Wiel/ NOAA/ Princeton)
(*) “Mild weather” is defined as temperatures between 64 and 86 °F, only a trace of rain (less than 0.04 inches) and low humidity (a dewpoint below 68 °F).
Dori and five chicks, 23 April 2014 (photo from the National Aviary falconcam at Gulf Tower)
The National Aviary has zoomed the Gulf Tower falconcam because this weekend — or early next week — the peregrine eggs at the Gulf Tower will start to hatch. It’s time for Hatch Watch!
Peregrine falcons delay the start of incubation until the female has laid her next-to-last egg, then incubation lasts about 32 days plus or minus a day or two. In this way, nearly all the eggs hatch within 24 hours. (The last egg hatches a day or two later.) The trick for us humans is figuring out when incubation actually begins.
This year we thought Dori finished laying eggs on March 15, when she had four, but she surprised us with a fifth egg before dawn on March 17. Her next-to-last egg was on March 15 so my guess is that incubation began around March 16. That means Day 32 is on April 17.
Here’s another way to calculate it. When Dori laid five eggs in 2014, the number of days from first egg to hatch was 41 days. This year her first egg was on March 8. 41 days later is April 18.
But I don’t really know.
If you’re a member of the Pittsburgh Falconuts Facebook page you’ve seen that John English predicted Hatch Date as April 15 or 16 plus or minus two days. My guess is April 17 or 18. Maybe you have a guess, too. Only Dori and Louie know for sure.
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