Category Archives: Climate Change

Birds Take a Taxi to Correct For Climate Change

Male European pied flycatcher (photo from Wikimedia Commons)

9 October 2023

Birds like the European pied flycatcher (Ficedula hypoleuca) that winter in the tropics and southern hemisphere do not use weather clues to tell them when to fly north in the spring. Instead they cue on changing day length and return at the same time every year. But as Earth’s climate changes, spring comes weeks earlier than it used to and their migration timing is out of sync. Scientists in the Netherlands decided to give a few lucky birds a lift (a Lyft?) to Sweden and it made all the difference.

Pied flycatchers prefer to nest in or near oak trees where their nesting season is timed to correspond with the peak of caterpillar season. Unfortunately, spring is two weeks earlier now in the Netherlands, pied flycatchers arrive too late and have locally experienced a 90% decline.

Female European pied flycatcher carrying caterpillars (photo from Wikimedia Commons)

The old timing of Netherlands’ spring is now found in southern Sweden so scientists at University of Groningen in the Netherlands and Sweden’s Lund University decided to see what would happen to migration and nesting success if a few pied flycatchers were transported (by car!) from the Netherlands to suitable habitat in Sweden.

Anthropocene Magazine reports, “For three springs, starting in 2017, scientists from the University of Groningen in the Netherlands and Sweden’s Lund University caught newly-arrived Dutch female pied flycatchers and drove them by car to a nesting spot 570 kilometers (354 miles) away in southern Sweden that was already home to other pied flycatchers.”

Range of European pied flycatcher (map from Wikimedia Commons)

The experiment was wonderfully successful. The Netherlands’ females were in sync with the food supply and were twice as prolific as their Swedish counterparts who were locally out of sync. After spending the winter in Africa the former-Netherlands females returned to Sweden and so did their offspring!

Later the research team proved that migration timing is genetically inherited in European pied flycatchers by taxiing a few eggs laid in the Netherlands to Swedish nests. Those offspring returned to Sweden the following spring on the Netherlands timing.

Taxi service cannot be the answer to out of sync migration but birds are adapting on their own. During the study, banding still continued at Netherlands nests and some of those youngsters were found nesting in Germany, halfway to Sweden. They flew there on their own.

Read more about the taxi ride experiment in Anthropocene Magazine: For some birds, a “taxi” helps recalibrate out-of-sync migrations.

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

The Heat Loop

Hot weather sunset (photo from Wikimedia Commons)

26 July 2023

The weather is hot and getting hotter. Excessive heat plagued the West, Texas and Florida and now, in the next 6-10 days, the heat will move southeast with soaring temperatures at 100°F+.

U.S. 6-10 day temperature outlook, 31 July – 4 August as of 7/25/2023 (map from NWS)

It’s not just the air that’s hot, the ocean is too. This timelapse video from Colin McCarthy @US_stormwatch shows ocean temperature anomalies from 22 February to 21 July. The hottest colors — the highest above normal — are off the Pacific coast of South America and in the North Atlantic near Newfoundland.

Warming water off the coast of South America is the developing El Niño, part of the cyclical El Niño–Southern Oscillation (ENSO) that affects weather and climate around the world.

The real surprise is off the coast of Newfoundland where Colin McCarthy says “The North Atlantic is in uncharted territory. The entire ocean basin is a record-smashing 1.5°C (2.7°F) above normal.”

Both are easier to see in this static map from NOAA.

NOAA sea surface temperature anomaly (partial map) as of 24 July 2023, 0600 EDT

Hot water makes the air hot as Newfoundlanders can tell you. Summers are usually so cool there that only 1 in 5 households in St John’s, NL have air conditioning, at least as of 2019. That is probably changing this summer as temperatures soar into the 90s.

Hot water makes hotter air makes hotter water in an endless feedback loop.

With El Niño on top of climate change I don’t think it will end well.

p.s. Today’s news Florida ocean records ‘unprecedented’ temperatures similar to a hot tub!

(photo and map credits are in the caption; click the links to see the originals. The Heat Loop diagram is by Kate St. John)

Drought: The Long and Short of It

View of South Mountain from Queen Creek, AZ (photo from Wikimedia Commons)

12 July 2023

Short term:

Last Friday, 7 July, Pennsylvania was placed under a statewide drought watch by the PA Department of Environmental Protection. They evaluated four factors to make the decision: precipitation, surface water flow, groundwater level, and soil moisture. The most worrisome was low groundwater in 16 counties and a 90-day rain deficit in Elk and Warren.

And then it rained in central and eastern PA and the Drought Condition map changed. Most of the state is now in the green (good) or yellow zone. Except for low groundwater in 14 of our 67 counties, the drought appears to be short term because a good rain can clear it up. See the Before and After, July 9 and 11, in this slideshow.

USGS Pennsylvania Drought Condition monitoring as of July 9 and 11, 2023

Long term:

Meanwhile, Arizona is not in a drought right now but it’s a desert, its water supply is limited, and it suffered a long term drought for many years. Water allocation has to be planned in Arizona so they won’t run out. This prompted Phoenix put the brakes on development last month in places that rely on ground water.

Arizona will not approve new housing construction on the fast-growing edges of metro Phoenix that rely on groundwater thanks to years of overuse and a multi-decade drought that is sapping its water supply. …

Officials said developers could still build in the affected areas but would need to find alternative water sources to do so — such as surface or recycled water.

Driving the state’s decision was a projection that showed that over the next 100 years, demand in metro Phoenix for almost 4.9 million acre-feet of groundwater would be unmet without further action, Hobbs said. An acre-foot of water is roughly enough for two to three U.S. households per year. …

Hobbs added that there are 80,000 unbuilt homes that will be able to move forward because they already have assured water supply certificates within the Phoenix Active Management Area, a designation used for regulating groundwater.

TribLive: Drought, water overuse prompt Arizona to limit construction in some fast-growing parts of Phoenix

I’ve marked up this Google map of Phoenix to show the fastest growing areas circled in red.

Map of Phoenix, AZ metro with circles added: 5 fastest growing suburbs (screenshot from Google Maps)

Back in the 1990s I had a friend in the City of Phoenix’s economic development department who was proud to predict that, based on the city’s projected level of development, they had 75 years of water. In other words, they were OK until approximately 2070. My thought at the time was “Only 75 years?? Then what??”

Now we know. It took only 30 years to put the brakes on.

p.s. Phoenix, in Maricopa County, is one of the fastest growing areas of the U.S.; Maricopa grew 20.55% since 2010. Being from Pittsburgh, where Allegheny County grew 2.89% in the same time period, I marveled at the notion of 80,000 unbuilt homes.

(photo and map credits are in the captions, click on the links to see the originals)

Climate Change Will Move Bald Eagles Away From Home

Pair of bald eagles at Chincoteague NWR, Virginia, 2010 (photo from Wikimedia Commons)

9 July 2023

A decade ago we thought climate change was a slow moving train but now it’s heating up so fast that new calculations predict we will hit the +1.5°C (2.7°C) global temperature mark in the next five years. The National Audubon Society’s Climate Initiative predicts that most bird species will shift northward. Unfortunately our national symbol, the bald eagle, will leave much of its favorite range in the U.S.

The Audubon Society predicts that three-quarters of the bald eagles’ current summer range will become unsuitable for the birds in about 60 years.

“A lot of their breeding is going to shift completely into Canada and Alaska. So the lower 48 is looking less ideal for breeding conditions for the species,” said Brooke Bateman, senior scientist at the National Audubon Society.

Yale Climate Connections: How climate change could hurt bald eagles

At +1.5°C — in the next five+ years — the biggest decrease will be in a swath of the Southeast and Lower Mississippi Valley. This screenshot map of bald eagle climate vulnerability is tiny on purpose so that you’ll view it on the Audubon website. Click here, then scroll down to see the maps for winter/summer.

A global temperature rise of +3.0°C will reduce bald eagle nests in a huge swath of the U.S. from Maryland, Virginia and North Carolina westward to Nebraska and Arkansas. This is unhappy news for Pittsburgh where red indicates a 15% loss of bald eagle nests under the +3.0°C scenario. [Again, view this map on the Audubon website. Click here, then scroll down to see the maps for winter/summer.]

Bald eagle predicted summer range change when climate change heats +3.0 degrees C (screenshot from zoomed field guide bald eagle account)

Sadly, climate change will prompt our national bird to move away from home.

Read more about the Audubon climate change report at Yale Climate Connections. See the affect of climate change on the bald eagle’s range in the Audubon Field Guide:

(photo from Wikimedia Commons, screenshot from field guide bald eagle account)

Yes, It’s a Drought

White snakeroot (Ageratina altissima) wilting in Schenley Park, 7 June 2023 (photo by Kate St. John)

9 June 2023

Plants are drooping, water levels are low, and clouds of dust engulf dirt roads in western Pennsylvania. It hasn’t rained for almost three weeks at a time of year that’s usually wet. Yesterday it became official. We’re in a drought.

Every week the U.S. Drought Monitor at University of Nebraska-Lincoln issues a nationwide drought assessment. Pennsylvania is labeled “SL” on this week’s map for evidence in both Short term and Long term indicators. (Click here for the latest Drought Map.)

Pennsylvania is in Short-and-Long Term Drought, 6 June 2023 (map from US Drought Monitor at UNL)

Most of Pennsylvania, including Allegheny County, is in Moderate Drought.

Much of PA is in Moderate Drought, 6 June 2023 (map from US Drought Monitor at UNL)

The drought seems sudden but it’s been building for a while. Precipitation was above normal last year through January 2023 but starting in February it fell off. April and May were seriously below normal. June has been bone dry so far. As of today Pittsburgh has a year-to-date precipitation deficit of 4.55 inches.

Monthly precipitation in Pittsburgh: Normal 1991-2020 (green) and 2023 actual (red) (graph from Climate for PBZ at )

Even the hardiest invasive plants are wilting in the city parks …

Mugwort drooping from lack of water, Hays Woods, 3 June 2023 (photo by Kate St. John)

… small tributaries are completely dry …

High water and no water at waterfall, Schenley Park, 7 June 2023 (photo by Kate St. John)

… and the cascade pools in Schenley Parks’ Phipps Run are stagnant. Unfortunately stagnant water is a breeding ground for mosquitos, an unexpected consequence of drought.

Low water in cascade pool, Phipps Run, Schenley Park, 7 June 2023 (photo by Kate St. John)

The forecast calls for rain on Monday 12 June, but one day’s rain can’t overcome the 4.5+ inch deficit.

Hoping for more rain soon. Meanwhile check out these drought tips for lawns and camping at TribLive: Dry conditions expected to continue in Western Pennsylvania.

(photos by Kate St. John, maps from U.S. Drought Monitor)

Bad Air Today, Fewer Warblers This Fall?

Sunset in Pittsburgh 3 June 2023. Pink sun due to Canada’s wildfire smoke (photo by Jonathan Nadle)

6 June 2023

On Saturday evening Jonathan Nadle took a photo of the setting sun glowing pink with threads of smoke across its face. The color was the result of wildfire smoke drifting in from western Canada.

Today Pittsburgh and much of the northeastern U.S. are under an air quality alert because the smoke is now at ground level. We don’t see it as smoke — it looks like haze — but the particles have put our air quality forecast into Code Orange = “Unhealthy for Sensitive Groups.” Young children, seniors, and those with respiratory problems should limit outdoor activities.

AirNow forecast for Pittsburgh PA on 6 June 2023

NBC News explains:

Millions of people across the Midwest are under dangerous air quality conditions Monday, as smoke from wildfires in eastern Canada wafts over the region.

Hazy skies have blanketed a wide swath of the country from the Ohio Valley to as far south as the Carolinas. Air quality advisories are in effect Monday in southeastern Minnesota and parts of the Upper Peninsula of Michigan, as well as in more than 60 counties in Wisconsin.

The spike in air pollution comes from wildfires that have been raging in the Canadian provinces of Quebec and Nova Scotia.

… Canada is experiencing one of the worst starts to its wildfire season ever recorded.

NBC News: Air quality levels in parts of the U.S. plunge as Canada wildfires rage, 5 June 2023

There are wildfires across much of Canada right now — west and east — but the fires affecting Pittsburgh today are mostly in Quebec and nearly all are out of control, displayed as red dots on Canada’s interactive wildfire map. Click here or on the screenshot below to see the interactive map.

Active wildfires in Canada, Quebec wildfires circled in pink, 6 June 2023 (map from Canadian Wildland Fire Information System)

For Pittsburgh the smoke is mostly an inconvenience but for Canadians it is dangerous and for the birds that nest in these forests it is deadly. The fires are happening where northern warblers breed including bay-breasted, blackpoll, palm, Cape May and Tennessee.

When we see fewer of these migrating warblers in the fall, the fires will be partly to blame.

Tennessee warbler (photo by Donna Foyle)

Unfortunately as climate change heats up the Earth and reduces rainfall, we can also expect more fires in North America’s forests.

Click here to see AirNow’s interactive air quality map centered on Pittsburgh, PA

(see photo and map credits in the captions)

Air Quality UPDATES

28-30 June 2032:

Wildfire smoke is back again, worse than before.

6-7 June 2023:

7 June 2023, 5:00am: The winds have changed. Pittsburgh air is still Unhealthy for Sensitive Groups this morning but it is much worse elsewhere. It is Very Unhealthy from Harrisburg to Philadelphia (purple), and Hazardous to breathe in a wide swath of Ontario including Ottawa (brown).

6 June satellite map:

AirNow interactive map as of 7 June 2023, 5:00am

Fewer White-throated Sparrows?

White-throated sparrow (photo from Wikimedia Commons)

19 May 2016

A study seven years ago of bird population trends predicted that climate change would cause most species to decline while a few would increase. In May 2016 I wrote about two species whose fates would be different.

Did this prediction come true?

The maps below show population trends during the non-breeding season. The white-throated sparrow’s trend map for 2007-2020 indicates their abundance dropped 30% in the lower Mississippi area and on the East Coast from New York to North Carolina.

White-throated sparrow non-breeding season population trends 2007-2020 (map from eBird Status and Trends)

Surprisingly, robins experienced regional decline as well, though not in Pittsburgh.

American robin non-breeding season population trends 2007-2020 (map from eBird Status and Trends)

I’ve noticed the drop in white-throated sparrows during their peak migration in early October and mid-to-late April. American robins seem the same as ever here in Pittsburgh

Have you seen a change in white-throated sparrows? Let me know.

(photo from Wikimedia Commons, maps from Cornell University eBird Status and Trends; click on the captions to see the originals)

Pollen Season Gets Worse Every Year

Oak tree in bloom with dangling pollen flowers (photo by Kate St. John)

25 April 2023

If your pollen allergies have gotten worse there’s a good reason for it. A study of North American pollen trends in the last 30 years, led by William R. L. Anderegg, found that pollen season is starting earlier, lasting longer and has higher pollen counts than in the 1990s because of climate change.

Yale Climate Connections reports “In Anderegg’s research on pollen in North America, he saw pollen seasons starting about 20 days earlier than they did in the 1990s” and pollen concentrations increased by 21%. The higher temperatures and carbon dioxide in today’s atmosphere make plants more productive and allergies worse.

Right now in Pittsburgh we are at the height of pollen season. Recurring hot weather, 15+ degrees above normal, caused the oaks to bloom early and pollen so intense that my car turned yellow while parked at Anderson Playground for just an hour last Friday.

Allergy sufferers get a double whammy here because the pollen is added to Pittsburgh’s poor air quality making it particularly dangerous for children and people with asthma and respiratory illness.

A sneeze! Pollen allergies are in for a bad time (photo from Wikimedia Commons)

So, no, you’re not imagining it. Pollen season in North America is bad and is still getting worse.

Scientists predict that average pollen counts in 2040 will be more than double what they were in 2000.

Allergies and climate Change, Harvard School of Public Health
Shaking a pine bough, releases a cloud of pollen (photo from Wikimedia Commons)

Track the pollen count and get the daily forecast at

screenshot of pollen map on 25 April 2023 from


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

Bird Populations Are Trending North with Curious Exceptions

Blue jay (photo by Steve Gosser)

19 April 2023

Last November eBird enhanced their Status and Trends website with cool interactive maps of overall abundance, weekly abundance, population trends and range for nearly 700 species. The population trends are fascinating for two reasons: northward movement and curious exceptions.

Many eastern species are moving their breeding ranges northward. For some it’s starkly obvious that they’re declining in the Southeastern U.S. and increasing in the northern U.S. and southern Canada. Click HERE to see 12 good examples at Cottonwood Post.

Blue jay (Cyanocitta cristata) trends are doubly fascinating. Jays are definitely moving north but with a curious exception in south Florida (why increasing there?). Check out their trends map. Blue is good, red is bad.

Blue jay breeding season population trends 2007-2021 (map from eBird Status and Trends)

Most of Pennsylvania has no change in blue jay abundance but did you see the tiny red dot near Pittsburgh? Where is that decline? Drill into the map on the eBird website using these step-by-step screenshots to guide you.

First, click to Explore all Status and Trends Species on eBird. When you get there, click on Search all species at top right.

screenshot from eBird Explore all Status and Trends

I searched for Blue Jay and got a global map. Click on the [Trends] button. Still too tiny! Click on the + sign at top left to zoom in.

screenshot from eBird Explore all Status and Trends: blue jay

As I zoomed in it became apparent that nothing has changed (i.e. white dots) for blue jays in our region until I found that red dot in Cranberry Township. I hovered my cursor over it and found that blue jays declined there 7.5% from 2007 to 2021. I wonder why…

screenshot from eBird Explore all Status and Trends: blue jay

Meanwhile wood thrushes (Hylocichla mustelina) are the curious exception. Though declining overall their trends map doesn’t show the predictable north-south pattern.

Wood thrush singing (photo by Steve Gosser)

Wood thrushes are declining in the Northeast but increasing in the Southern Appalachians and Alabama. A line of “No Change” runs from approximately Kingston, Ontario to Charlottesville, Virginia. Again, I wonder why…

Wood thrush breeding season population trends 2007-2021 (map from eBird Status and Trends)

Try this for yourself at Explore all Status and Trends Species at eBird.

(photos by Steve Gosser, maps from Cornell University eBird Status and Trends)

ebird species migration weekly abundance trends

Armadillos Are On Their Way to Pennsylvania

Nine-banded armadillo, Santa Ana National Wildlife Refuge, Texas (photo from Wikimedia Commons)

2 April 2023

Here in Pennsylvania when we see a photo of an armadillo we immediately think “Texas,” but we could just as well think Tennessee. Nine-banded armadillos expanded across Tennessee in less than 50 years and by the end of this century, probably sooner, they’ll walk into Pennsylvania. Their current (2006) and future ranges are shown on the map below.

Current and predicted U.S. range of the nine-banded armadillo as of 2006 (map from Wikimedia Commons)

Northward expansion is nothing new for armadillos. Originally from South America, where there are still 20 species, armadillos are part of the Great American Interchange that began 6.7 million years ago when Panama’s land bridge joined North and South America.

The surprising thing about armadillos, though, is that their expansion in the U.S. is nearly ten times faster than the average rate expected for a mammal. How soon they get to Pennsylvania depends on the speed of climate change.

Armadillos have no fur so they are sensitive to cold weather but not all of it. Yale Climate Connections says, “Researchers now believe that armadillos can thrive as long as average minimum temperatures stay above about 17 degrees Fahrenheit.” Pittsburgh has 12 to 32 days each winter that drop below 17, which are probably too many for an armadillo.

But just wait. They’ll get here. This video explains how and why.

video from Backyard Ecology on YouTube

Read more about their range expansion at Yale Climate Connections. Learn about armadillos at “Armadillo Online!

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