The disease-carrying American wigeon/Clemson University

With the avian pandemic having now reached Alaska and the human disease Covid-19 gone endemic, maybe it’s time to take a deep breath and contemplate nature’s role in population dynamics.

For almost 3,699,998,000 years after life began on this planet an estimated 3.7 billion years ago, the laws of nature limited the size of the populations of all species. If they got too big, nature whittled them down either with famine or disease.

Then along came homo sapiens who were, for most of their existence, bound by the same rules.

When the human global population pushed near 450 million people in the 1300s – a massive increase over the estimated 18,500 humans on the planet a million years earlier – along came the plague or what was then described as the “Black Death.”

It wiped out 17 to more than 22 percent of the human population at the time, or some 75 million to 100 million people.  To put this in perspective, the same percentage today would amount to a new disease killing about 1.5 billion of the more than 7.7 billion people living on the planet in 2019.

The SARS-CoV-2 virus responsible for the disease Covid-19 was first detected near the very end of 2019. It has since then killed nearly 6.3 million people or about 0.08 percent of the global population. 

Almost 470 million people are known to have survived the disease, although the number is likely far greater than that given the number of people who have been infected but suffered no symptoms (those “asymptomatic” cases) and the number of people who didn’t get sick enough to bother getting tested.

Though Covid-19 is nothing like the Black Death in terms of reducing the human population, or even the Spanish flu of 1917-18 that killed somewhere between 1 percent and 5.4 percent of the global population, it has scared the hell out of many and brought warnings that more pandemics are coming.

“We’ll have another pandemic. It will be a different pathogen next time,” Microsoft founder Bill Gates has warned.  OK, Gates is a computer whizz and not a trained biologist, but the scientists involved in studying infectious diseases are saying the same thing.

“Pandemic risk is largely underestimated and actions to prepare for outbreaks are grossly underinvested,” according to the experts at the Center for Global Development. “The spread and severity of Covids-19 felt like a surprise to many policymakers – a clear case in point. But careful analyses are suggesting that future pandemic risks are significant.”

All of which brings this back to the now raging avian pandemic (guard your backyard chickens!) and the laws of nature.

Asking for trouble

The highly pathogenic avian influenza virus (HPAI) H5N1 was first discovered in southern China in 1996 and, like the SARS-CoV-2 virus, has been mutating into new variants ever since as it has made its way around the globe.

The “current H5N1 bird flu viruses were first identified in Europe during the fall of 2020 and spread across Europe and into Africa, the Middle East and Asia, becoming the predominant subtype globally by fall of 2021,” the U.S. Centers for Disease Control reported in March.

“These viruses have been spreading in wild birds in much of the world and causing sporadic poultry infections and poultry outbreaks in many countries, most recently the United States.”

The French ordered the killing of 2.5 million poultry in January to try to control the disease.

“The spread of highly pathogenic avian influenza, commonly called bird flu, in Asia and Europe, has raised concern among governments and the poultry industry after previous outbreaks led to the culling of tens of millions of birds and trade restrictions,” U.S. News & World Report said at the time.

By early April, NPR was reporting ‘some 24 million poultry birds like chicken and turkeys have already been lost, either because they died from the virus or were killed to prevent its spread” in the U.S., and fretting about what might happen to waterfowl, raptors and other birds that had by then been found to be infected.

Though the virus tends to quickly sicken domestic poultry, wild birds appear more resilient. The latest variant of the virus, in fact, first popped up in a duck shot by a hunter on the East Coast early this year.

“So far we have no indication that HPAI has jumped from wild migratory birds to poultry, and we’d very much like to keep it that way,” South Carolina State Veterinarian Michael J. Neault, the head of the Clemson University Livestock Poultry Health,  said in a statement shortly after the university’s Veterinary Diagnostic Center made the first diagnosis in an American widgeon.

The diagnosis was quickly confirmed by the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service, which then issued an alert for laboratories everywhere to be on the lookout for the disease.

It soon showed up in hunter kills all along the East Coast – a mallard in Virginia, a blue-winged teal in Florida, and a lesser scaup in Maryland – then started moving east – a snow goose in Kentucky in mid-February, a redhead duck in Indiana in early March, a Ross’s snow goose in South Dakota later that month, an American green-winged teal in Colorado in early April, and a Canada goose in Wyoming near the middle of April.

Meanwhile, the kill was on at poultry farms, the avian incubators for this kind of disease given large numbers of birds living close together.

All this in turn due to the ever-growing global demand for cheap protein to feed the ever-increasing number of humans.

A chicken explosion

The world chicken population, according to the data-tracking Statista website, numbered just over 10 billion in 1990. By 2020, the number had more than tripled to 33 billion. 

Few of these chickens are free-ranged; most are raised in chicken sheds. The U.S. Department of Agriculture in May 2015 reported 233,770 poultry farms in the United States. 

A dozen years earlier, when the University of Wisconsin-Madison set out to answer the question of whether anyone can make “a living raising pastured poultry on a large scale,” it could find only a dozen farmers across the country engaged in serious farming of free-range chickens.

None of them appeared to be making a lot of money raising chickens. The big money was and is in raising large numbers of chickens for the major companies in the business of selling processed chicken to consumers.

“Today, we pay nearly $820 million annually to the more than 3,600 poultry farmers who contract with us,” Tyson Foods brags. “When they succeed, our own business does better. In fact, a 2022 study by Agriculture Economist, Dr. Thomas Elam found that the median income of contract poultry farmers was significantly higher than both all farm households and all U.S. households.”

The birds are raised in densely packed sheds that can become hotspots for infections.

“A flock of about 240,000 chickens owned by Tyson Foods Inc. in Kentucky tested positive for a highly lethal form of bird flu,” Reuters reported in February at just about the time that infected snow goose showed up in the same state. 

The chickens were part of a widening “outbreak that threatens the U.S. poultry industry,” the news service added. The poultry being killed since has only grown.

Researchers are now at work on a functional vaccine for chickens as for people.

“While avian flu vaccines are currently available, they are not being used on a large scale on poultry farms because this hinders the ability to conduct surveillance testing, which helps detect the virus in unvaccinated flocks and limit the spread of the disease,” according to the University of Wisconsin-Madison.

“A future vaccine would need to be effective for all different strains of the virus, as it changes over time, to be feasible for widespread use.”

UW-Madison research is working on such a vaccine and “hopes it will help protect flocks from future outbreaks of avian influenza,” the university added. “Such outbreaks are becoming more frequent, the reasons for which remain under investigation.”

Actually, the reason for why this is happening is pretty simple. It’s called nature.

The more animals of any kind living in close contact the greater the chance for pathogens to infect them and spread. This is why some cities and states try to discourage people from feeding ducks.

Infection basics

As the University of California-Davis well sums the duck-feeding problem:

“In the wild, a particular lake or pond habitat can sustain a certain number of ducks and/or geese – there is a maximum number of individuals that can successfully reside there indefinitely, with enough food, water, and shelter. This carrying capacity of the habitat can be artificially increased when supplemental food is added. 

“While extra food may appear to be a good thing, it may lead to an expanded waterfowl population beyond the carrying capacity of the habitat. Without increasing space and other resources, ducks and geese can become stressed and overcrowded. Increased numbers of animals leads to increased competition for food; weaker birds in these environments often sustain severe injuries from more dominant birds. During the spring breeding season, gangs of male ducks physically attack each other to get access to female ducks. This not only leads to plucked featherless areas and skin lacerations, but females often drown as they cannot escape the driven males.

“Overcrowded habitats also are prime territories for disease outbreaks. There have been numerous outbreaks of botulism, avian cholera, duck plague (duck enteritis virus), and aspergillosis (fungal infection) in urban duck ponds where supplemental feeding is a regular activity. The intense competition for poor quality food combined with other stressful interactions often cause the ducks and geese to have suppressed immune systems, which reduces their ability to resist infection.”

This is nature at work, and the same rules apply to all species although hmans have created a miracle in bending the rules. Human manipulation of the environment has allowed the global, human population to explode from about 1 billion people in 1800 to more than 7.8 billion today.

It took homo sapiens almost 300,000 years to reach that 1 billion mark. It took only about 130 years to double it to 2 billion and less than 50 years to double that 2 billion to 4 billion.

“Remarkable” is the only word that can be used to describe what the species has done to subvert to allow this to happen. But it is impossible to wholly run away from nature, which wants all things to die because that is how nature works.

Despite the number of people dead in the latest human pandemic – that number being large or small depending on how one looks at it – we have stumbled forward with barely a blip in our overall numbers.

And thus it is foolish to think we can avoid another pandemic. Nature has never allowed any species to increase in number indefinitely as we are doing. We have pushed the boundary far beyond where anyone could have imagined even 100 years ago.

Science, in the form of the so-called “Green Revolution,” helped beat back the threat of global starvation on a mass scale that threatened only 60 years ago, and modern medicine has for decades now managed to hold our death rate far below our birth rate.

But it’s simply illogical to think we can push the boundaries of global carrying capacity for humans infinitely out into the never-before. There’s a limit there somewhere, and the laws of nature dictate that a species will face evermore threats to individual survival the closer to the limit the species gets.

Either we will begin to run out of food, as was predicted in the ’60s, or we will get hit with another pandemic, as Gates and others now warn; or we will witness a war of global destruction.

Because there are really no alternatives. The human population simply can’t go on increasing forever unless it finds another planet to begin pioneering.