The common nighthawk (Chordeiles minor) is my Spark Bird, the species that got me hooked on birds when I was only 10. That was a long time ago when gravel roofs were still common and so were flying insects(*). Since then nighthawk populations have declined precipitously.
Lack of flat roofs, pesticides, increased predation and loss of habitat are noted factors of their decline. Further unstudied potential causes of decline include climate change, disease, road kills, man-made towers (posing aerial hazards), and parasites.
The absence of flat roofs (made with gravel) in urban settings is an important cause of decline. In an effort to provide managed breeding areas, gravel pads have been added in the corners of rubberized roofs; this proves acceptable, as nesting has been observed.
Now that gravel roofs are scarce we notice a decline in Pittsburgh every time one disappears. A nighthawk family used to breed on a roof on Craig Street, the only gravel roof left in the neighborhood, but in August 2020 (after the birds fledged) the gravel was replaced with plastic. No more nighthawks here.
Common nighthawks are virtually gone from the eastern U.S. Their range map in North America used to include our region but eastern states are now dark gray = “Outside the Modeled Seasonal Range.”
eBird Regional Trends show an even bleaker picture in state-by-state declines. The map below shows the double-digit percentage (>10) losses in orange and gains in green, 2012-2022.
Pennsylvania’s median trend was -29.12%. Colorado, the only state to gain nighthawks, had a 11.43% increase.
While birding with friends on 16 May at Presque Isle State Park we heard quite a few American robins extremely upset by something in a tree. Eventually I found their problem: a common nighthawk was roosting on a branch. Perhaps this species is so unusual, even to robins, that they had to remark on it.
Common nighthawk, Presque Isle State Park, 16 May 2026 (photo by Charity Kheshgi)
Seeing a nighthawk nowadays is a gift. Every nighthawk is a victory.
The story of my Spark Bird is described in this vintage article from 2009: Not So Common Nighthawks.
The eaglets likely passed from Avian Influenza. Their symptoms and the progression of the illness is consistent with Avian Influenza, and they could have contracted it from ingesting goslings and geese that had been brought to the nest as food. We cannot know for certain without testing, but this is the most likely cause based on the evidence.
Ducks, geese, chickens and pheasants figure heavily in the spread of avian influenza because they are most susceptible to catching it. Interestingly they are closely related and stand alone in the phylogenomic supertree(pink square below). Birds that are not related to ducks and chickens, and birds that don’t flock are very unlikely to catch the disease.
Our hearts go out to all who love these eagles and are grieving. We have been blessed with 100% survivorship of eaglets from the Hays/Glen Hazel eagle nests over the past 14 years, while it is typical for 30% of eaglets to not survive until fledging age.
Kudos to the Glen Hazel moderator team for promptly noticing signs of illness in the chicks and notifying Tamarack Wildlife Center’s Executive Director and Licensed Rehabilitator Carol Holmgren on Friday morning, May 15. Carol immediately reached out to Pennsylvania Game Commission (PGC) and Fish and Wildlife Service (FWS) colleagues, to loop them in that day, and has been in conversation since then. A few updates:
• It is FWS policy to let nature take its course at eagle’s nests and only approve intervention when there is a threat to the eagles that has a clear human cause such as fishing line entanglement or swallowing a fish hook. In this instance, the eaglets were ill, but not with a clear human cause where FWS and PGC would approve intervention. Much as that is difficult for us to witness, it is part of the natural history that eagles live with daily.
• The eaglets likely passed from Avian Influenza. Their symptoms and the progression of the illness is consistent with Avian Influenza, and they could have contracted it from ingesting goslings and geese that had been brought to the nest as food. We cannot know for certain without testing, but this is the most likely cause based on the evidence.
• The adults may also have been exposed to the virus. They typically have a stronger immune system than the young birds, and may be able to fight off the virus. Time will tell. We will be monitoring them. There is no treatment that can be given while they are free-flying. If one is on the ground due to illness, it may be able to be treated by a rehabilitator.
• Our hope is that their immune systems are strong and they can remain healthy.
• Our highest concerns at this point are 1. supporting the health of the remaining adult eagles and 2. caring for the moderators and community who love these eagles.
• Now that the two eaglets have passed, PGC has had extensive discussions about the risks vs benefits of accessing the nest to retrieve the now two deceased eaglets. They have decided not to pursue retrieval, in part to not stress the adult eagles through human presence at the nest.
• There is no practical benefit to confirming that the eaglets succumbed to Avian Influenza, beyond the human desire to know. The disease is known to be endemic in Pennsylvania now and there are no management actions that would be taken with that information.
• Due to the regulations and Acts protecting eagles and their nests, any access to the nest would also require both PGC and FWS support.
• PGC will be continuing to monitor the situation. If an eaglet should fall to the ground, they may pursue retrieval and testing since stress on the adult birds would be less, and FWS approval would not be needed.
Below is the full statement shared by our colleagues in PGC today. We appreciate the thoughtfulness with which they have considered this situation, and their continued collaboration.
The Pennsylvania Game Commission (PGC) appreciates the concerns of the public regarding the eagles in the Glen Hazel Eagle Nest Cam, located in Allegheny County.
Wildlife watching opportunities, especially ones that can occur from anywhere thanks to wildlife cameras and digital technology, are a popular way for the public to learn and love wildlife.
Unfortunately, nature can be hard to watch at times. When situations occur on live wildlife webcams, including this eagle’s nest, human intervention is not always recommended or possible.
PGC evaluated the situation carefully and considered many factors including human safety and exposure to potential pathogens. Additionally, human intervention could further stress the adult eagles. Any actions must also comply with federal regulations related to the Bald and Golden Eagle Protection Act. At this time, we have chosen to not intervene. If a safer opportunity presents itself in the future, we may pursue disease testing to hopefully determine what caused the death of these eaglets.
You’ve probably heard of “Dress for Success” career advice. Today we’ll explore dressing for outdoor success to avoid Lyme disease.
This spring there are so many black-legged ticks (Ixodes scapularis) that unless you are vigilant it’s very easy to get a tick on your body, be bitten, and quite possibly get Lyme disease. How vigilant do you have to be? It depends on what you wear.
If you wear summer clothes that expose your arms, legs and toes you’ll need to check frequently while outdoors and check very carefully when you come inside. Look at your ankles and between your toes. Look behind your knees … and in other places you don’t want to expose to the public. This chart does not check toes and ankles because it assumes you’ll wear socks!
How to do a tick check (image from PA Dept of Health & CDC.gov)
Light-colored long-sleeved shirt with collar. Ticks are trapped under collar!
Socks long enough to put over your pant legs.
Hat with brim. Good for sun, too!
Closed-toe shoes.
This 1+ minute video illustrates what to wear with extra tips. NOTE: The video says to spray your skin with DEET. Alas, no. DEET prevents mosquito bites but it does not repel ticks.
At the time, Chernobyl was in the Soviet Union. Five years later, in December 1991, the Soviet Union dissolved and Ukraine and Belarus became independent. In 1996 the radiation exclusion zones spanned three countries: Ukraine, Belarus and Russia. Note how close the power plant was to the Belarus border.
By 2016 it was safe enough to go on guided tours in the ghost town of Kopachi within the 10km Chernobyl exclusion zone. Here a tour guide shows his Geiger counter reading in Kopachi. (Don’t linger!)
However two years later a 2018 study, published in the journal Environment International, found that cows as much as 140 miles away from the original disaster were still producing radioactive milk. The air was OK but a long-lived radioactive isotope in the soil, cesium-137, is easily taken up by the plants the cows consume and it gets into their milk.
According to the New York Times in 2018, the milk was five times the Ukrainian government’s official limit for adults, and more than 12 times the limit for children.
It is easy to see how this could happen. The cows pictured at top in 2005 were drinking water in a drainage ditch whose purpose was to gather water that cleansed radioactive isotopes from the contaminated soil. The photo caption reads:
Water drainage trenches like this one in Jelno – a village some 300 km away from the Chernobyl Nuclear Power Plant — removes excess water from the peaty soil as a first step. The next step is to diminish the content of radionuclides in the soil by ploughing and introducing mineral fertilizers. Caesium and potassium are chemical twins. Hungry for minerals, a plant will pull out caesium from the contaminated soil but if potassium is in good supply the plant prefers mineral fertilizer. (Jelno, Ukraine, July 2005)
The 2018 study explained that the problem of radioactive milk could be fixed by adding hexacyanoferrate to cattle feed. This chemical binds with heavy metals, including cesium-137, but it is very expensive.
Unfortunately the problem is probably not being treated. Russia began their full out war on Ukraine on 24 February 2022(*) and there are more immediate dangers now than cancer. 40 years later the milk is probably radioactive.
For more about the Chernobyl disaster, see this documentary video from June 2019.
(*) p.s. The war in Ukraine is Putin’s effort to regain what the Soviet Union lost due to a combination of factors that included the Chernobyl disaster:
The Soviet Union collapsed on December 25, 1991, due to a combination of chronic economic stagnation, unsustainable military spending, rising ethnic nationalism, and the unintended destabilizing effects of Mikhail Gorbachev’s reforms (glasnost and perestroika). These factors, exacerbated by the 1986 Chernobyl disaster and falling oil prices, led to a loss of central control and the eventual independence of its 15 republics.
Brown creeper (from Wikimedia) and Golden-crowned kinglet (by Charity Kheshgi)
26 March 2026
Songbird migration kicks off with two small birds that are easiest to find if you can hear them.
The brown creeper (Certhia americana) climbs and zigzags up tree trunks and large branches, probing under the bark for insects. When he reaches the top he flies down to the base of the next tree and climbs up again. He’s hard to see because he flattens himself against the tree and his back matches the bark. However he makes a high pitched contact call that helps pinpoint his location.
Here’s the sound of a brown creeper foraging at Seal Island, Nova Scotia. Do you hear the low horn in the harbor? Can you hear the brown creeper’s call?
Golden-crowned kinglets (Regulus satrapa) are tiny birds that flit and hover as they forage for insects in the trees. Because they move a lot I notice them when I look at the silhouettes of bare branches against the sky. They also make high-pitched contact calls.
Here’s a golden-crowned kinglet calling as it forages in New Hampshire, repeating his single note throughout the recording. Near the end you’ll hear the low “brock” of a raven and then the “ank ank ank” of a red-breasted nuthatch. The kinglet speaks as well, before the raven and after the nuthatch. Can you hear him?
I used to identify these two species by sound but I cannot hear them anymore. Kinglets were the first to go. Seven years ago I wrote about upper-range hearing loss:
If you can’t hear kinglets [and brown creepers] you are probably over age 65, perhaps younger, and probably have age-related hearing loss. Presbycusis affects 1 out of 3 of people by age 65 and half of us by age 75.
See a video of loud golden-crowned kinglets in my 2019 article:
We think of Europe and Asia as separate land masses yet they are on one continent called Eurasia. In fact they used to be separated by the Turgai Strait which closed up 60 million years ago. But before the strait formed, they were stuck together. Here’s how plate tectonics affected Eurasia.
250 million years ago (million years is abbreviated Ma) Europe and Asia were in one large land mass called Pangaea which existed from 330 to 200 Ma. It included all the present day continents.
At 170 Ma Pangaea began breaking apart.
The Turgai Strait formed east of the Ural Mountains at 160 Ma. Europe and Asia separated.
The Turgai Strait was always somewhat shallow. By 60 Ma it became shallower and narrower and was closed by 29 Ma. Europe + Asia became Eurasia.
These static maps show the breakup of Pangaea with a thin yellow line for the location of the Turgai Strait. (NOTE: I think the 120 Ma map is inaccurate because it puts the Turgai Strait west of the Ural Mountains but it was always east. I drew the yellow line on the water anyway.)
Musing on Pangaea: How do we know all the continents were one big land mass?
The continents’ shapes fit together like a jigsaw puzzle.
Geologists found “matching geological trends between the eastern coast of South America, the east coast of North America (namely the Appalachian Mountains), and the western coast of Africa.” i.e. same rocks of same age in the Appalachians and NW Europe.
Fossils of the same animals and plants, all of the same age, are spread across the southern continents.
How long did Tyrannosaurus rex typically live? Until recently, research had pegged their life span at 28-30 years but a new study finds that T-rex did not reach full size until age 40, ten years after it should have died. The previous life span is open to debate.
Dinosaur bones have concentric growth rings (cortical growth marks, CGM) like the rings found in tree trunks. To count the bone rings (CGM), the team obtained slices of leg bones from 17 specimens and ground them so thin that light could shine through them. Illustration below: Pink and blue arrowheads point to growth rings below. Notice that the bone slice is shaped like a ring. Dinosaur bones are hollow, just like bird bones!
Earlier bone studies had ignored or not even seen the tightly packed rings so they estimated the life span at 28-30 years. This study counted everything. That’s how they reached 40.
Snow goose and domestic chickens: direct transmission of Highly Pathogenic Avian Influenza (photos from Wikimedia)
1 March 2026
Right now there’s a perfect storm of highly pathogenic avian influenza (HPAI) in Lancaster County, Pennsylvania with “all hands on deck” to stop it. Since 28 January 7.5 million birds have died in Pennsylvania.
USDA’s 30-day bird flu map shows that PA is the only state in serious trouble.
Pennsylvania is the fourth largest egg-producing state (after Iowa, Ohio and Indiana).
Lancaster County (LanCo) is the top egg-producing county in PA and one of the largest poultry and egg producers in the world.
To achieve this volume the county has quite a few large industrial chicken farms. Some of these house more than a million birds making LanCo the most densely poultry-populated county in the U.S.
Domestic chickens are highly susceptible to bird flu and this strain is especially deadly. It is called “highly pathogenic” or “high path.” (HPAI)
This is the first virus that can jump directly from wild birds to poultry.
HPAI has been in the U.S. since 2022 so why did it affect so many chickens this February?
The theory is that this winter was so cold and the lakes and rivers so frozen that overwintering snow geese went to whatever open water they could find. Some snow geese found water near poultry farms in Lancaster County (perhaps the Susquehanna River). The flu probably jumped from infected snow geese to domestic chickens (illustration at top).
Dr. Hamberg from the PA Dept of Agriculture explains the challenges on a visit to Lancaster County this week.
These top 5 HPIA outbreaks in Pennsylvania, 28 Jan through 28 Feb 2026, culled 6.7 million birds. They were all commercial egg-laying operations in Lancaster County. {Data is from USDA on 1 March 2026}
Starlings (European starlings, Sturnus vulgaris) are the invasive species Americans love to hate. They’ve only been on this continent for 136 years, having been successfully introduced in 1890 & 1891 in Central Park, New York. DNA studies indicate that every starling in the U.S. is descended from the Central Park group.
Have our starlings physically changed since they got here? Have they evolved differently from their native relatives in Eurasia?
In 2023 a team led by Julia M. Zichello(*) set out to answer that question. They measured 1,217 starlings including their beaks, wings and tarsi (plural of tarsus) using historical museum skins and modern birds from the U.S. and Eurasia, especially starlings in the UK.
Their study found that U.S. starlings have indeed changed from their Eurasian relatives:
Beak length in the native range has remained unchanged during the past 206 years, but we find beak length in North American birds is now 8% longer than birds from the native range. … Additionally, body size in North American starlings is smaller than those from the native range.
Graphs from the study show the differences in orange (U.S. starlings) and blue (native-range starlings).
U.S. birds have longer beaks (top graph and histogram).
Both native and U.S. birds have become smaller over time (bottom graphs) but the U.S. birds are overall smaller.
Figure 2 abbreviated description: (a) graph and (b) histogram: Whole beak length (mm) over time, Native range 1816–2022 (blue); introduced: U.S. range 1890–2020 (orange). (c) graph and (d) histogram: Whole tarsus length (mm) over time, Native range 1816–2022 (blue); introduced U.S. range 1890–2020 (orange). From Recent beak evolution in North American starlings after invasion, Julia M. Zichello et al, Nature.com.
Why did U.S. starlings make these changes?
Smaller size: A lot of reasons
The study says, “Smaller birds in North America, versus larger birds in the parent population, occurred rapidly on arrival and this trend has persisted today,” perhaps because (a) U.S. birds experience warmer summer temperatures than the native range (warmth makes organisms trend smaller), (b) starlings experienced “genetic drift” upon arrival, and/or (c) the founder population of birds (the 1890-91 group) may have randomly consisted of smaller bodied birds.
Longer beaks: Livestock grain vs. natural food
Longer beaks were the big revelation in this study and they conclude that it has to do with diet. U.S. starlings eat a lot of grain at cattle feedlots in winter (longer beaks are an advantage). Eurasian starlings don’t.
The most dramatic difference between starling diet in the U.S. and their native range is the intensity of their foraging at dairies and feedlots in the U.S., where they consume substantial amounts of food intended for livestock.
Since 1960, corn production in the U.S. has increased exponentially, which has also enabled a concurrent expansion of the cattle industry. By the 1960’s feedlot operators in several states were reporting major starling disturbance. In our data, 1960 is when we observe a marked increase in proximal starling beak length in the U.S. beyond what is observed in the native range at any time.
Starling flocks on U.S. dairies can exceed 10,000 birds and cause an estimated $800 million dollars of annual lost revenue across the country. … We estimate that starlings may consume [136 million lbs] of livestock feed per year in the United States. An individual bird can eat up to 2.2 lbs (1 kg) of feed per month, and 1,000 birds can consume 630 lbs (286 kg) every hour spent foraging at feedlots.
Traveling the PA Turnpike in fall and winter my husband and I often remarked on the “starling barn,” a dairy farm near Plainfield with a HUGE flock of starlings that always caught our eye as we passed. This winter the starlings were not noticeable, perhaps because USDA “helped” the farmers with their starling problem. Listen to The Controversy Over Controlled Poisoning Of Starlings from WBUR in January 2017. It’s an interview with Bob Mulvihill of the National Aviary.
Has there ever been a software update on your computer or cellphone that you really hate?
Aaarrg! My phone nagged me to reboot after auto-update, and now I hate how it works!
The update broke my favorite app!!!
Why did they hide the one feature I use every day? Where did they put it?
The old app I love doesn’t work anymore after system update. Now what?
I know I’m supposed to run updates but they always break something.
These reactions are quite normal and they have a name: Baby Duck Syndrome.
In human–computer interaction, baby duck syndrome denotes the tendency for computer users to “imprint” on the first system they learn, then judge other systems by their similarity to that first system. The result is that “users generally prefer systems similar to those they learned on and dislike unfamiliar systems”.[24] The issue may present itself relatively early in a computer user’s experience, and it has been observed to impede education of students in new software systems or user interfaces.
We often imprint on our first software just like baby ducks imprint on the first moving thing they see. This is probably how we humans are wired for survival. When we learn a tool that works we don’t want to give it up.
Imprinting isn’t dumb and it isn’t dumb to imprint. This video explains why.
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