Who knew that song sparrows have such amazing feather details?
Good digital photography lets us see more than we can with binoculars. Find out why in this 2012 vintage article: I Love Pixels.
(photo from Wikimedia Commons, click on the caption to see the original)
Every year Hope, the mother peregrine at the Cathedral of Learning, kills and eats some of her chicks as they are hatching. Among all the peregrine families on camera this behavior is quite abnormal.
This spring some of you wondered if Hope’s behavior would be passed down to her female offspring. The way to find out is to watch one of her daughters nesting on camera (the behavior cannot be seen otherwise).
Are any of her daughters nesting? Here’s the status of Hope’s fledged offspring:
In Hope’s nine years of nesting (2010-2018), she has averaged only 1.1 fledgling per year. None of them has ever been seen again.
By contrast Dorothy, the previous female peregrine at Pitt, averaged 3.0 fledglings per year. (If you don’t count her three elderly unproductive years her average was 3.7.) At least 12 of Dorothy’s kids went on to nest in the Great Lakes region, many on camera. Dorothy has children, grandchildren, great-grands and probably great-great-grands by now. She was a matriarch.
What is Hope’s legacy? So far as we know, nothing. We do know that none of her banded daughters are nesting on camera.
p.s. Hope’s potential of fledglings/year is higher than Dorothy’s. Hope averages 4.25 eggs per year at Pitt; Dorothy averaged 3.93. Hope has fewer fledglings/year because half of her hatchlings do not survive the hatching period.
(photo from the National Aviary falconcam at Univ of Pittsburgh)
(*) Living offspring: We will never know the fate of Hope’s 2 unbanded offspring because we cannot identify them. If they are both alive then Hope has 7 living offspring. Due to the 60% mortality rate among young peregrines, it is statistically likely that Hope has only 4 living offspring from 2010-2018, not 7.
.Details: Hope: 10 fledgings/8 years = 1.1 Dorothy: 43 fledgings/14 years = 3.0 –or– 41 fledglings/11 years = 3.7
If your eyes could focus this closely you’d see that the world through a water drop looks upside down.
Refraction through water also makes rainbows — seen in the spider web above — and optical illusions.
On a chilly damp morning Luc Viatour found a spider web displaying this illusion.
(photo by Luc Viatour (https://Lucnix.be) on Wikimedia Commons. Click on the caption to see the original)
By now in my series on Hawaii you’ve probably noticed that the rarest birds on the islands are threatened with extinction. Sadly this situation is normal. So many Hawaiian species have gone extinct and so many are on the edge today that Hawaii is known as the Extinction Capital of the World. The group of forest birds called Hawaiian honeycreepers are a case in point.
Five million years ago a flock of finches similar to redpolls (Carpodacus erythrinus) arrived from Asia, flying non-stop for more than 4,000 miles. When they arrived, Oahu and the Big Island didn’t exist, but over millions of years they spread out and evolved into 59 species of Hawaiian honeycreepers with a wide variety of beaks for exploiting Hawaii’s food sources. They diversified more than Darwin’s finches.
Each bird was perfectly evolved to survive Hawaii’s dangers but had no defense against off-island threats. Their exposure came with the arrival of humans. We came in two waves.
Polynesians arrived in Hawaii around 400AD and were here alone for 1,400 years. During that period 30% of the Hawaiian honeycreepers went extinct.
In 1778 Captain James Cook was the first European to see Hawaii, prompting immigration from the rest of the world. Since then, in just 240 years, another 39% of the honeycreepers have gone extinct. 18 species remain but six are so critically endangered they may be gone soon.
The slideshow above shows a fraction of what we’ve lost. The last bird, the black-faced honeycreeper or poo’uli (Melamprosops phaeosoma), is still listed as critically endangered with 1 to 49 individuals left on Earth. However, none have been seen since 26 November 2004. It’s probably gone.
Hawaii’s endemic birds go extinct so easily because of …
Avian diseases caught from mosquitoes are the big problem. Fortunately there’s a silver lining. One of the honeycreepers, the Hawai’ian amakihi, can now live with avian malaria and is expanding its range within mosquito territory.
This 27-minute video, made in 2005 by Susanne Clara Bard, tells the story of the Hawai’ian amakihi’s survival. Though this video is a lot longer than I normally post, it’s worth even a short look to learn why Hawaiian birds face so many challenges.
The Hawai’ian amakihi evolved to survive malaria in only 200 years.
(images from Wikimedia Commons; click on the links to see the species account at Wikipedia)
Tour Day 9: Leaving the Big Island of Hawai’i for home
You would not think that something this cute could be a problem but European rabbits (Oryctolagus cuniculus) have plagued Australia for 160 years. After a century of recurring population explosions (think “plagues of locusts”!) scientists found a virus that kills only European rabbits. They introduced it in 1950 and it worked amazingly well for a while but the rabbit and the virus both evolved. Here’s their story.
Introduced for hunting in Geelong, Australia in 1859, the European rabbit immediately went feral and the population went out of control. Without any predators they covered most of the continent by 1910.
Periodic population explosions, called rabbit plagues, became the norm. The rabbits eat everything. They devastate native plants, push out native animals, denude the countryside and cause dust bowls. In the photo below, at dusk, they are everywhere but probably not a plague yet since there’s still some grass.
Hunting and poisoning were ineffective.
Then in 1950 scientists found a virus in South America, called myxoma, that killed European rabbits. They released it in Australia (and in France) and it cut the rabbit population by 99%. Wow!
But a few rabbits lived and so did the virus. Science Magazine reports that “within a decade, rabbit numbers were on the rise again as some evolved resistance to this deadly infection and the virus itself became less deadly.”
This month, a new DNA study of both the rabbit and the virus shows that:
Rabbits on two continents evolved the same genetic changes to beat back the virus—before the virus itself changed and regained the upper hand. […and…] In the 1970s the virus developed a greater ability to suppress the rabbit’s immune responses. That change, as well as the natural emergence of another rabbit-killing virus, has caused populations to decline again.
— Science magazine, 14 February 2019
The arms race continues.
Don’t worry about the rabbits. They had another population explosion in 2004. At last count there are about 200,000,000 of them in Australia.
After all, they breed like rabbits.
For more information, read “Seventy years ago, humans unleashed a killer virus on rabbits. Here’s how they beat it” by Elizabeth Pennisi in Science Magazine.
(photos and range map from Wikimedia Commons. click on the captions to see the originals)
When severe drought, high temperatures and failing infrastructure hit Kamfers Dam in Kimberley, South Africa, the lesser flamingo colony that nests there was forced to make a dreadful choice. The lake usually provides food and their island provides shelter but the water was gone. Incubating adults were dying of dehydration. If the colony stayed, all would die so they abandoned this year’s breeding attempt — eggs and chicks — to live and breed again.
Kamfers Dam is a privately owned dam just north of Kimberley, about halfway between Johannesburg and Cape Town, South Africa. The site was originally an ephemeral wetland but became a permanent lake thanks to runoff and treated wastewater from the town of Kimberley.
In 2006 people noticed that the lake attracted a Near Threatened species, lesser flamingos (Phoeniconaias minor), so they built an S-shaped breeding island for them (pin on map above). At the height of the breeding season it’s covered in tens of thousands of flamingos.
Kamfers Dam is one of only six lesser flamingo breeding sites in the world and an international birding hotspot … until this year.
In January, because of severe drought and high evaporation, a large part of the lake went dry. The lake level could not be restored by the water treatment plant because of their own failing infrastructure.
The flamingos abandoned their desiccated colony, so people went out to rescue the chicks. Click here or on the screenshot below to see a video of the rescue posted by Saan Staan Kimberley on Facebook.
2,000 flamingo chicks and eggs, some in the process of hatching, were rescued by volunteers and taken to shelters around South Africa.
Then the hard work began — three to four months of feeding and monitoring thousands of flamingo chicks, many of whom arrived in bad shape from dehydration and starvation. Added to that is the challenge of not allowing them to imprint on their human rescuers. South Africans made a worldwide plea for volunteers.
The National Aviary stepped up to help. Terry Grendzinski, Supervisor of Animal Collections and avian specialist, knows all about raising baby flamingos so she flew to the SANCCOB rescue center in Cape Town. In the photo below she feeds one of the rescued chicks while wearing pink sleeves and back gloves to mimic the appearance of the chick’s parents. Click here to watch a video of the feeding.
So far, so good. The chicks are growing, preening and sunning in their enclosure (video below). Some are already standing on one leg!
Thanks to this massive rescue effort, this year’s lesser flamingo breeding season at Kamfers Dam will have a silver lining. You can donate here at the National Aviary to help these baby flamingos.
(credits: rescued chick at top, Terry G feeding a chick, and video of chicks in blue enclosure courtesy of National Aviary. Map of Kamfers Dam embedded from Google Maps. Video and screenshot of rescue at the dam from Saam Staan Kimberley on Facebook. Click on the captions to see the originals)
Among the heroes of the peregrine falcon’s restoration in North America, Tom Cade was legendary. During his lifetime peregrines went from plentiful to nearly extinct. Today their population is healthy and growing, thanks in great part to Tom Cade’s efforts and dedication. He died this month at age 91.
Tom Cade was a falconer nearly all his life. He became hooked on peregrines at age 15 when one flew close overhead on its way to capturing prey. That was in the early 1940s when the peregrine population was still healthy in North America.
By the mid 1960s Dr. Cade was the head of Cornell Lab of Ornithology, the peregrine population was in free fall, and he could see it happening. The situation so alarming that he and other raptor experts were desperately trying to find out why before it was too late.
In 1965 they convened a conference about the peregrine’s decline at the University of Wisconsin, Madison that became the catalyst for peregrine recovery. At that point they knew the decline was due to DDT and dieldrin but they had no proof. (Proof came later from Derek Ratcliffe.) Meanwhile, agricultural experts argued it couldn’t be caused by pesticides; the pesticides were so useful.
In a 2015 video on the 50th anniversary of the Madison Conference, Tom Cade told how the conference changed the peregrines’ future. The transformational moment came when Jim Rice, a renowned falconer and naturalist from Pennsylvania, spoke nine words. It changed Tom Cade’s life. See him tell the story here.
After the conference Tom Cade was key in all that happened next, especially in shaping the captive breeding program and peregrine reintroduction. DDT and dieldrin were outlawed in the early 1970s. By 1999 peregrine falcons were plentiful enough in the western United States that they were removed from the Endangered Species List.
In 1970 Tom Cade co-founded The Peregrine Fund and worked with them for the rest of his life to conserve raptors around the world. See their tribute and remembrance video here.
We all stand on the shoulders of the great conservationists who went before us. We mourn Tom Cade’s loss but we celebrate his incredible contribution to conservation and to peregrine falcons.
Thank you, Tom Cade. Your inspiration lives on.
Read Tom Cade’s obituary in the New York Times. His book, Tom Cade: A Life in Science and Conservation by Tom Cade and Clinton M. Blount is available here on Amazon. The cover, which illustrates this article, shows Tom Cade with his gyrfalcon, Krumpkin, 2008.
(credits: Information on Tom Cade’s life is drawn in part from his obituary in the New York Times. photo: Cover of Tom Cade: A Life in Science and Conservation by Tom Cade and Clinton M. Blount via Amazon)
In the winter of 2012 Pittsburghers noticed we had very few blue jays in our area. It was such a mystery that I posted an article in February asking folks to tell me if they’d seen any blue jays lately. Seven years later the responses are still coming in.
Most people respond when they don’t see any blue jays because they miss them. It turns out that blue jay frequency varies throughout the year and can drop locally when the habitat changes, especially if oaks are cut down. (Blue jays rely on acorns.)
Our blue jay count surges during spring and fall migration because a lot of them breed north of us. In Allegheny County (Pittsburgh) there’s also a mysterious mini-surge every year in mid February. What’s that about?
See seven years of blue jay reports and musings at Have You Seen Any Blue Jays Lately?
Count your own blue jays during the Great Backyard Bird Count this weekend. How many birds will you find?
(image credits: Great Backyard Bird Count poster, eBird report on frequency of blue jay sightings in Allegheny County, PA, 2014-2019; click on the captions to see the originals)
The 100th Meridian West is an imaginary line on the map that happens to mark the climate divide between the humid east and arid west in North America. Or rather, it used to. The rainfall divide is moving east.
Extending from the North to South Poles, the 100th runs longitudinally in the U.S. from North Dakota through Texas.
Its coincidence with the rainfall divide was first documented in 1877 by John Wesley Powell who found during his explorations in the Great Plains that the 100th was a visible boundary. Locations to the east of the 100th received 20+ inches of annual rainfall, the west received less.
20 inches is a key number for agriculture and human population. It determines what you can grow, whether you have to irrigate and, thus, how many people can live there. Powell saw the line and told Congress it had implications for settlement of the western plains. Congress didn’t heed him but …
This 2014 map of U.S. Population by County shows that it played out as Powell expected. You can see the rainfall divide in population density. People choose to live where there’s water.
You can also see the line from outer space. I’ve marked the 100th (approximately) on this satellite photo of Nebraska. The landscape is deep green to the east though not uniform.
Nowadays the 100th is no longer the rainfall divide.
A study by Columbia University meteorologists found that the aridity line has shifted 140 miles east and is now statistically located at the 98th meridian. Climate change will move it even further as warming evaporates moisture in the northern plains and alters rainfall in the south.
In a hundred years the aridity mark may be firmly inside Minnesota, Iowa and Missouri. Aridity decreases the amount of agriculture and will probably change the population. People choose to live where there’s water.
John Wesley Powell’s “100th meridian” is moving east.
This article was inspired by Yale Climate Connections. Read more here in Yale Environment 360, 11 April 2018.
(photos from USDA, USFS and Wikimedia Commons; click on the captions to see the originals)
Last year I learned that charts change hearts and minds better than words do. Our brains process visual information better than text.
I was reminded of this human tendency when I read in The New Yorker about the burgeoning Flat Earth movement. Members became believers when they saw YouTube videos claiming there’s been a coverup and that the Earth is actually flat.
This 2017 video sparked controversy as viewers tried to process his intent. Satire or Science?
Seeing is believing.
(video from YouTube; click the YouTube logo to see the original upload)
