Humans Boom while Birds Crash

Starling murmuration
European Starling murmuration (James Wainscoat: Unsplash)

The United Nations estimates that our population reached 8 billion this week. In 1900, it was 1.6 billion but by the turn of the 21st century, we had grown to over 6 billion. That is nearly 2 billion more mouths than only 22 years ago and the graph is still rising. Meanwhile, most wildlife populations across the globe are plunging. There’s a connection and it’s called the Sixth Great Extinction.

It is harder to estimate populations of birds than terrestrial animals, but North America alone is reckoned to have 3 billion fewer birds than 50 years ago. Seventy species out of a total of over 500 are thought to be close to a tipping point, meaning the threshold for sustaining their presence.

The Cornell Lab for Ornithology released a tool this month that maps trends in the abundance of birds from 2007 to the present. The data were provided by citizen scientists through eBird and mapped in 27×27 km squares (roughly the area of a small county). Birders and gardeners have noticed fewer birds in their localities, especially “common” birds, and this impression now has numbers. Typing the name of any species prompts the map of North America to show the trend in blue boxes for an increase, red for a decrease, and white where it can’t yet be determined with confidence.

I tested the tool for the mid-Atlantic region where I live. The good news is that geese and swans have increased spectacularly, and waterbirds and ducks are doing well too. The protected status of wetlands where there is less pollution and human disturbance is probably responsible.

There are reassuring trends for some raptors (eagles, owls, and the Red-shouldered Hawk) as well as for vultures and ravens. The Pileated Woodpecker, Carolina Wren, Wild Turkey, and Ruby-throated Hummingbird hold up well too.

But the news overall is bleak. Insectivorous species are down from a loss of habitat and prey, a large group that includes warblers and swallows. American Robins and Gray Catbirds are declining, but whatever is responsible hasn’t affected Northern Cardinals that have overlapping habitats. Hearing American Crows every day, I am surprised they are in decline, and will likely appreciate them more if they become rare!  

We can do little about the rising human population, but every landowner can help to mitigate the decline in birds by making their property a friendly habitat. This should be easier because few birds are regarded as pests. Many are beautiful and some provide services we appreciate. Farmers can leave field margins fallow for foodplants and insects to thrive. Roadside verges and hedges should be mowed and pruned after the breeding season and boring roundabouts planted with wildflower seeds. Gardeners can set aside corners of their yard for nature to creatively flourish, often as beautiful as a tidy flower bed. Our individual efforts seem paltry against the scale of the problem, but taken together they amount to an area much larger than nature preserves.

If I am around in another 15 years, I am confident of seeing more blue boxes than red on the eBird map if we manage the land differently.

Mastodon in Our Town

Not Mastodon the heavy metal band from Atlanta, but a heavy, leathery mastodon from Virginia. It is the first found east of the Blue Ridge. A local bricklayer was hunting on private land one day in 1983 when he found a strange object near a muddy creek. As he couldn’t identify it, he asked the geologist Jerre Johnson who realized it was the tooth of an elephant. An elephant in America—had Barnum & Bailey’s Circus been in town? But this animal was quite different to African and Indian elephants today, from a line that became extinct about 11,000 years ago. They are related species, but mastodons split early from a common Proboscidea ancestor, presumably trekking across a land bridge between Asia and Alaska ahead of mammoths that came later.

The private owners of the land forbad excavation, but when they sold it the new owners gave permission for excavation by Dr. Johnson, now Emeritus Professor at the College of William & Mary. He led a dig involving dozens of volunteers, including archeologists, Eagle Scouts, and many members of our chapter of the Virginia Master Naturalist program. It became a triumph for citizen science.

A breakthrough came after ten days of fruitless digging when the dirt started to yield its fossil treasure, including more teeth, ribs, limb bones, and broken tusks seven feet long and six inches wide at the base. The beast was old judging by its molars which were worn down by a rough diet. This was not a grazing species like modern elephants, but a browser of tree branches and leaves.

Mastodon fossil
A tusk in protective plaster

Fossils in the coastal plain are not living matter turned to rock, they are the real thing. In eroded outcrops of this region, you can find strata of mussel shells inches thick. They look as fresh as if they were washed up from the rivers or Chesapeake Bay by recent storms, but may be a few million years old. Likewise, we had real mammoth bones, not rocks, although they no longer had the gleaming white freshness of shells. Dr. Johnson distributed them for his volunteers to wash and dry, and I was given a hefty chunk of what I guessed was the head of a humerus. The tusks were coated in plaster to protect them on their journey for display at the Virginia Living Museum (humorists take note), but unfortunately not enough of them were preserved for assembling a skeleton.

Mastodon tooth
See the nipples on the molar

I was curious how mastodons got their name. Was it from the huge muscles needed for mastication? When the first fossils were discovered two centuries ago they mystified geologists who called the new species, ‘Incognitum.’ It was the French geologist George Cuvier who coined the name mastodon, although this was later dropped by taxonomists for the more ponderous, Mammut americanum. I previously blogged about the curious names chosen for new animals to science, sometimes they are more whimsical than biologically meaningful. Cuvier chose mastodon, which means ‘milk tooth,’ because the crowns of the molar teeth looked like nipples. You can see on this picture why he chose a quirky name. The teeth don’t resemble those of any other kind of elephant, extant or extinct, which is why they can tell a mastodon from a mammoth.

The discovery was so unusual that it interested the Smithsonian Institution and the Washington Post. One day soon, carbon dating will reveal the fossil’s age, and perhaps museum conservators will deduce whether score marks on the ribs were made by the claws of a saber-toothed cat or a dire wolf.

We know that mastodons died out at the end of the last Ice Age with other megafauna, but was their extinction caused by climate change or Clovis hunters? I guess it was an irresistible convergence of the two, which are the same threats facing elephants today and so many other species of animals and plants. Central Africa has lost 100,000 (64%) to poachers and habitat loss in the past decade alone. I missed live mastodons in our town by a whisker of geological time, and dearly hope that future generations will have more than elephant bones to marvel at.

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The Return of the Native

Blogger_at-workApologies to anyone who recently visited my blogs posted between January and March 2013 and found the pictures were missing. This was a widespread problem affecting WordPress bloggers, but the images have now been reloaded.


A large black-and-white bird flying above our yard towards the James River caught my eye last week. It was no “buzzard.” A bald eagle is still uncommon enough to be arresting, and perhaps there is even a patriotic American somewhere who stands to attention when he sees his national emblem soaring past, like Air Force One. But there is a grander reason for saluting the bird—it is a native that has returned home.

Eagles were a common sight in the Chesapeake Bay watershed until catastrophes in the 1950s and ‘60s. In those decades, an industrial plant was disgorging poisons into the James River. The chemical waste was Kepone, an insecticide related to DDT, which so polluted the river that a Virginia Governor prohibited consumption of fish for a 100 mile stretch. But no respecters of law, eagles kept fishing. Not only did they accumulate poison from eating fish but also lead from the scattered gunshot of duck hunters. Hardly a single chick could be brooded in those days. Those woes were aggravated by the loss of nest sites to waterfront developments, and the failure of naïve birds to navigate around traffic and power lines. It seemed as if the 1940 Act of Congress intended to protect the species had been written on disappearing ink.

Photo: Don Snyder

Forty years ago you would have been lucky to have seen a single eagle along the James; fewer than thirty pairs nested across the entire state. But after the poisons were banned by the EPA in 1972 river health slowly improved, which encouraged the US Fish and Wildlife Service to launch a program for reintroducing eagles. It is perhaps the greatest American conservation story for a single species. Nest sites are monitored annually by fly-overs in light aircraft, and at the last count there were over 700 breeding pairs in the state, allowing the species to be delisted from the Endangered Species Act. So the bird depicted on the escutcheon of the Great Seal of the United States can now be seen even within Washington DC itself, and that is something that even congressmen who put business before conservation should be proud of! 

On that eagle day, my mind was pulled away from its absorbing interest to thoughts that had no obvious connection.  I found myself thinking about Clym Yeobright in Thomas Hardy’s The Return of the Native. When an image comes out of the blue like that I often strain to find a meaning for the unexpected distraction. I suppose there was something inside me trying to fathom a metaphor for what I had just seen.

Clym Yeobright and his wife Eustacia in The Return of the Native

In the novel, Clym returned to his birthplace on Egdon Heath after making his fortune in Paris. It had been hard growing up on the Heath, but he believed it would be easier now to flourish in the bosom of land that had nurtured his ancestors, where old neighbors would celebrate his return and he could settle down to productive work with a wife and family.

Perhaps the novel came to mind because I was uneasy remembering how things turned out for the returning native and deep down was wondering about the fortunes of eagles back in their homeland. But unlike Clym, who needed no help moving to the Heath, bringing species back often needs our helping hands, the very hands that originally extirpated them. The job of preserving species seems unfathomably difficult to me, and is yet so immensely important for preserving the web of life and a healthy planet, which some call Gaia. But since human populations are continuing to migrate from rural origins to urban communities it is easy to forget our dependence on biodiversity. Connections between sources of our food, clothing, medicines, and raw materials for manufacturing and building on the one hand and living things “out there” on the other are under-rated or taken for granted. Without beloved companion animals inner city dwellers might even forget that we share the planet with other creatures. And when we do think of human ecology we find it overwhelming and hope that someone else is working on it.

The United Nations has designated our times as a Decade of Biodiversity. It is an admirable attempt to draw global attention to environmental sickness, even if the politicians themselves are soon distracted by the latest humanitarian disaster (caring for the one species instead of for all). Unfortunately, no one I asked had ever heard about this splendid declaration—nor had I before preparing this post—but the responsibility for preserving biodiversity really should fall on our shoulders, and the efforts of government, NGOs, researchers, and citizen scientists need our support.

Since zoos, wildlife parks, and technology can only go so far towards preserving species, rare animals and plants must eventually be reintroduced to their old habitats. The international organization that reports population status and coordinates reintroduction programs is the IUCN. It publishes the famous Red List of species that are threatened or endangered, including those that are extinct. A Threatened species is one that is vulnerable to stepping down the list to Endangered, the dire category which used to include bald eagles. Searching the List for threatened species is quite sobering because it includes 41% of all amphibians, 34% of conifers, 33% of corals, 31% of sharks and rays, 25% of mammals, and 13% of birds around the world. Diners are relieved that most types of lobster are safe, at least for now (1%).

When humans become urbanized the disconnection with nature makes it harder to notice or even care about year-on-year changes in the natural environment or that a formerly abundant species has now grown scarce. Like the drip-drip of a retreating glacier, it is only by observing over a period of time that you notice how far it has retreated up the mountain. At least that is how I rationalize the gap between my impression that songbirds are as common as ever in my backyard and the fact that national bird counts reveal alarming trends over my lifetime.

It is a sad reflection on the character of Homo economus that both the UN and conservationists feel it is necessary to appeal to our self-interest to encourage conservation-mindedness. One of their favorite examples is the Amazon jungle, for which preservation is sought for the cornucopia of potentially valuable products and medical remedies for ourselves. Perhaps we would feel more concerned if we lived five times longer than our four score years, since we would then have to face a more impoverished landscape in our own lifetime. But for me the moral argument is so much more powerful: that if we live more gently with nature we can avoid the curse of posterity for grandstanding and being grand executioners during the sixth great extinction on earth. This is the only extinction we cannot blame on geology or asteroids.

If the resources available for research and conservation were stretched thinly enough to cover most threatened species nothing could be achieved, so hard choices have been made. Those getting most attention are well-loved or iconic species, and many of them sit at the top of the food chain, like eagles. Golden lion tamarins (Brazil), Siberian tigers (Asia), black-footed ferrets (Great Plains), and gray wolves (Yellowstone National Park) have been successfully reintroduced, and the publicity helps to prime the pump for funding other projects. But what about more lowly species that are nevertheless important for supporting those above them in the chain? Who is going to help half-a-million species of beetles?  The physiologist J.B.S. Haldane pointed out that God must have had “an inordinate fondness” for them, so surely they deserve some attention?

I have a particular fondness for the red kite story because forty years ago I drove with student friends to Tregaron Bog in mid-Wales to see the last survivors in Britain. Before persecution they thrived throughout the country where they provided equivalent services to vultures in other countries. We only had a fleeting glimpse of two rusty-colored raptors with forked tails as they flew over the wetland, but this was enough to tick them on our checklists, as crazy birders do, before turning for the long journey home. We anticipated their imminent extinction, but some years later healthy birds were brought over from Europe to found a thriving population now numbering about 2,000 pairs. The bird has been seen again in London and hunts the countryside of Hardy’s Wessex novels.

Yet behind these sweet stories eternal vigilance is needed as the price of biodiversity, to twist an expression often attributed to Thomas Jefferson. Habitats are not static, human pressures come and go and come again, and the globe continues to warm, encouraging competitive alien species, melting ice shelves under polar bears, et cetera. Besides, not everyone welcomes the natives home. Developers grumble that people should have a greater call on waterfront properties than eagles, ranchers in Wyoming and Idaho keep their guns handy watching for wolves, and an English student even complained that a red kite had swooped down for his sandwich! Restoring species to their habitats is patient work, and never ending.

That brings me back to Thomas Hardy who, as a Victorian, was lucky not to live in such anxious times. Life didn’t turn out well for Clym, the returning native. He never settled down happily and found himself at odds with residents and married a belle who became dissatisfied after he fell into poverty, working as a laborer cutting furze on the cruel Heath.

I always hope that after suffering trials sympathetic characters in the novels I read will be rewarded with a contented and harmonious life, but that never happens in the Hardy world where fate trumps hope. The author may have called himself a realist, but pessimism is an unattractive demeanor that curbs endeavor and can be a self-fulfilling prophecy. I wish it had been Jane Austen who had come to mind on my eagle day because Jane-AustenDarcy returned to Longbourne to marry Elizabeth Bennet and they lived happily ever after, and that is the metaphor I wish for all returning natives.

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