The Sandhill Crane: Tastes Like Pork

Double-crested cormorants faced the challenge of becoming “overabundant.” Their numbers were so low for so long that more than one human generation grew up never seeing large gatherings of cormorants, either at their northern breeding grounds or favorite southern wintering quarters. When cormorant numbers rebounded after DDT was finally banned in 1972, fishermen, politicians and even bird watchers were astonished at their numbers. And for some, even though cormorant populations were probably still below their historic highs, the bird’s large flocks were seen as “out of control” and the birds were eating too many fish. So they, meaning catfish farmers, fishermen, and government technicians, shot them – by the tens of thousands. The remains of the birds were usually composted onsite or elsewhere since the meat is inedible. A cruel, terrible waste of food chain energy and biomass.

Now it is the Sandhill Crane, Grus canadensis, that comes under the gun as an “out-of-control” species. After decades of conservation efforts in many locations to protect thinning numbers of rare sandhill cranes, threatened due to overhunting in the 1930s, conventional wisdom now turns to lethal measures to control a perceived overabundance. The evolutionary line of cranes goes back about 10 million years, with distinct sandhill crane ancestors appearing about 2.5 million years ago. Like cormorants, there are several subspecies of sandhills, but unlike cormorants some are rare or endangered.

Sandhill cranes, typically do not deal with fish in their diets, so they’re not in competition with fishermen or fish farmers. The cranes are basically opportunistic herbivores, living off whatever plants or seeds are available, so they can manage to find food in drier upland areas as well as shallow wetlands. Sandhill cranes dine on wild berries, seeds of many kinds, and when the possibility presents itself, small mammals, reptiles, amphibians, and invertebrates such as snails and insects. What actually brings them into conflict with man, farmers in particular, is their decided taste for cultivated foods such as corn and wheat. Sandhills frequently target recently planted corn and wheat fields, much like cormorants raid the densely stocked catfish ponds in the South in search of an easy meal.

To protect their fields, farmers in Wisconsin are requesting the creation of legal hunting seasons for sandhill cranes. More than a dozen states, with more in the offing, have established seasons, bag limits and takes for this once rare bird. Unlike cormorants, however, the flesh of sandhill cranes is edible and is reported by hunters to taste much like pork chops, so the birds are not merely killed, but also consumed.

Regardless of whether the carcasses are destined for the compost or the dinner table, it seems, at best, inefficient to spend decades reviving a rare, threatened species only to turn around and put it in hunters’ sights. What is really ignored here is the questioning of why the birds feed at agricultural sites rather than at open upland ranges or food-rich shallow wetlands. The one-word answer is habitat. Every day more and more open land is taken out of the natural food chain and converted from prairie or open range or upland habitat or wetland to real estate – development or reclamation projects, leaving wildlife without a natural home, driving it into conflict with humans.

In science fiction literature and physics thought experiments it’s common to postulate what happens when human subjects are locked in suspended animation and time goes on without them. When they awaken the world has changed and there is no place for them in the future. The return of nearly-extinct species sometimes falls into this type of scenario. There often comes a point when threatened wildlife species regain some of their original stature, attempt to re-colonize former territories and expand into new ones, but during the decades of their absence people forgot what they were, how plentiful their numbers had been, and their place in the ecosystem. In that future the returning wildlife has lost its claim to respectable habitat and moves into territory appropriated by humans in its absence, setting the stage once again for lethal control measures of “overabundant” species, even the ones that taste like pork.

My book The Double-Crested Cormorant: Symbol of Ecological Conflict is now available in a  hardcover version at www.amazon.com, www.barnesandnoble.com and the University of Michigan Press, www.press.umich.edu which also offers an E-book edition. Also, check your local booksellers for availability.

For insights into the book, log on to my Author Page at Amazon at www.amazon.com/author/dennis-wild.  

What's Happening to Our Bats

Bats. Thought threatening by some people, our bats, rather than fearsome creatures, are harmless minders of nature and keepers of its balance. Bats, like bees and their cousins are pollinators, not only helping to produce our fruit and decorative flowers, but at the same time devouring millions of insects that might otherwise torment humans or damage fragile, economically important crops. And like other animals such as birds, squirrels, mice, and chipmunks they transport plant seeds as they search for food, ensuring continued plant diversity.

The problem now is they’re dying off, by the millions.

The cause, White-nose Syndrome (WNS), was discovered and photographed in a New York cave in 2006 where hibernating bats were observed with unnatural white noses. It was further documented and named the following year by biologists from the New York State Department of Environmental Conservation (NYSDEC) who witnessed erratic bat behaviors and hundreds of dead bats in scattered bats across the state. The U.S. Fish and Wildlife Service reported that “more than a million hibernating bats have died since then, making WNS the worst wildlife health crisis in memory.” The disease plagues multiple species of bats in caves and mines in sixteen states and four Canadian provinces with lethality of near 100 percent in hibernating bat populations.

Although the actual cause of death in these bats is not understood, the Fish and Wildlife Service describes the white muzzle growth as a newly discovered cold-loving fungus, Geomyces destructans. In lab experiments, 100 percent of bats exposed to G. destructans developed WNS. The spores of the fungus are apparently spread bat-to-bat, but like many pathogens may have other paths of infection.

G. destructans is undoubtedly the culprit, but where did it come from and why now? Some species of bats in Europe are known to display white noses, but show none of the symptoms of the disease. A paper published in the journal Emerging Infectious Diseases uncovered data showing that the white-nose growth in European bats was caused by G. destructans infection. The authors of the article proposed that the fungus had probably originated in Europe but did not kill the bats because the flying mammals and the fungus had evolved together, with the bats eventually developing immunity to the attacking fungus. North American bats evolved in the absence of G. destructans and so had no such immunity when it attacked.

The question the paper does not attempt to answer, or even propose a theoretical model for, is how the fungus or its spores were introduced to a new continent and how it managed to find its way into the depths of North American  mines and caves. The transport mechanism is still unknown, and may never be understood. It seems though another invasive species has found a new home with no natural controls to keep the fungus in check.

Why be concerned about the bats? Why spend the time and research dollars? The bat’s insect-killing potential replaces tons of insecticides that would be needed to protect crops and eliminate swarms of biting mosquitoes. The same mechanism that allowed the fungus to gain a deadly foothold in the caves could someday be responsible for the introduction of an invasive species that attacks farm stocks, fish farms, agricultural products, or perhaps even humans.

Thriving bat populations are another indication of a healthy environment. Millions of dead bats tell us that something is very wrong.

My book The Double-Crested Cormorant: Symbol of Ecological Conflict is now available in a trade hardcover version at Amazon.com, Barnes and Noble.com, and the University of Michigan Press, which also offers an E-book edition. Also, check your local booksellers for availability.

For insights into the book log on to my Author Page at Amazon at www.amazon.com/author/dennis-wild.

Learning To Be Big

There is a waterway on Cape Cod, actually a number of them by the same name, this one in Wellfleet, called the Herring River. Several towns on the Cape have named streams after the once ubiquitous river herring (now protected and prohibited from use as bait by recreational anglers and from harvests by commercial operators) that enters their tidal streams every spring to spawn. Like many other game fish, striped bass follow and ambush the herring on their spawning run. Herring are to the bass like Snickers bars are to trick-or-treating kids on Halloween.

The tidal Herring River in Wellfleet flows under Chequesset Neck road into Wellfleet Harbor, a beautiful corner of Cape Cod Bay. The river is physically separated from the bay by a dike equipped with self-adjusting tidal gates, creating a tailwater situation on each side as the tide floods and ebbs.

The river side of the dike, because of its warmer water and flow of nutrients and plankton, has become a tidal nursery for juvenile forage fish, particularly menhaden, an oily filter-feeding fish, known locally as “pogies” or in some areas “bunker,” greatly sought after by game fish such as striped bass and toothy bluefish. The Herring River, in nature’s whimsy, is also a summer nursery for “snappers,” juvenile versions of “slammers,” the jumbo adult bluefish that perpetually pursue schools of roaming adult pogies.

It was a clear, bright day in October, Columbus Day actually, when I stood on the river side of the dike observing the interplay between the huge schools of two-inch pogies and the roving schools of voracious snappers.

The pogies when at rest aligned themselves facing into the fast current feeding on the rich plankton crop drifting past. Virtually every single-celled planktonic organism, animal, plant and crossovers, contains a droplet of oil within its membrane or cell wall to help regulate its depth in the water column; the same oil that gives pogy flesh its oily texture. This type of feeding behavior is a rehearsal for later life when, as twelve-inch fish, pogy schools filter millions of plankton on an almost continuous basis. And like the rehearsal by the pogies, the snappers of Herring River prepare for later life as ten-pound-plus marauding predators, by cruising beneath the tiny pogies, individually charging toward the surface attacking a individual pogies from the rear and devouring it, either completely or leaving behind a shocked, bleeding head. The flash of silvery bluefish scales told the story each time a young pogy lost its future prospects.

The pogies somehow, in their own way, recognized the protective benefits of living and feeding in schools, and at the same time, accepted the reality of being converted to omega-rich bluefish flesh at almost any time in their lives.

This snapper -pogy interaction takes place every fall in virtually every bay and estuary on Cape Cod. There is a certain peace that comes while observing the process from atop the Wellfleet dike. In a time of great despair for some people, it’s possible to stand there and imagine the sequence playing out on the Cape for the last hundred centuries, since the last melting glaciers deposited their sandy burdens creating the Cape. It also produces a sense of reassurance, reflecting on how that same predator-prey relationship might continue forever, or at least until the last factory ship grinds up the last pogy for cat food or fish oil capsules.

My book The Double-Crested Cormorant: Symbol of Ecological Conflict is now available in a trade hardcover version at Amazon.com, Barnes and Noble.com, and the University of Michigan Press, which also offers an E-book edition. Also, check your local booksellers for availability.

For insights into the book log on to my Author Page at Amazon at www.amazon.com/author/dennis-wild.

Natural Cormorant Controls

One of the major issues I discuss in my book published by the University of Michigan Press, The Double-Crested Cormorant: Symbol of Ecological Conflict, is the role the southern catfish industry played in the extraordinary recovery of cormorant populations following the species’ near annihilation due to DDT.

The ban of DDT in the United States in 1972 promised a better future for Phalacrocorax auritus, the double-crested cormorant. Every year thereafter the birds would face lower burdens of the persistent insecticides in their food, eggs, offspring, and environment. What effectively was a booster shot to the cormorant recovery was the virtually simultaneous depletion of predators such as Atlantic salmon and lake trout in the Great Lakes due to overfishing and pollution. As the predators disappeared, populations of both native and non-native forage fish species, preferred food of cormorants, bloomed entirely out of proportion. The birds’ higher reproductive success rates coupled with massive schools of prey there for the taking at their breeding grounds drove cormorant numbers toward previous historic highs. One of the remaining population-controlling factors was the food sources at the cormorant’s southern wintering grounds.

At about the same time commercial fisheries crashed on the Great Lakes, southern row-crop farmers turned to the channel catfish as an alternate or supplemental crop. Catfish farmers never anticipated the fantastic growth in cormorant numbers, so gave little thought to protecting the heavily stocked catfish ponds from wintering cormorants. Thousand, perhaps tens of thousands of double-crested cormorants, fed all winter on the millions of unguarded catfish offered up by the growers. With rich plentiful food at both ends of their migration, cormorant numbers surged further – some local populations doubling in three years. Soaring bird numbers brought increased conflicts with Great Lakes fishermen and southern catfish producers resulting in cruel culling programs legally and illegally killing and wounding thousands of wild, federally protected cormorants.

The issue of the catfish industry affecting cormorant numbers should be taken into account when considering future lethal measures in cormorant management. Many catfish farmers facing huge increases in the cost of corn/soy catfish feed products closed some or all of their production ponds. Some were drained, plowed over, and restored to corn and soybean production. Other ponds were converted to the raising of largemouth bass, cultivated in less densely populated ponds, making them more difficult targets for P. auritus to attack. In either case, fewer catfish were available to hungry wintering cormorants, reducing the number of fatted, healthy birds prepared for the arduous migration north. From 2002 to 2011 every southern catfish-producing state experienced large decreases in acreage dedicated to channel catfish cultivation; overall acreage for U.S. catfish production shrank by 49% in those nine years.

This decrease in U.S. catfish production does not at all relate to the continuing, if not increasing, popularity of catfish fillets as table fare. In the seafood game, domestic farm-raised channel catfish products rank sixth in the United States. The gap in the U.S. between lower catfish production and increased consumption has been filled by foreign imports – particularly Pangasius catfish, farm-raised on the Mekong Delta of Vietnam. If the term Pangasius catfish doesn’t ring a bell it’s because domestic catfish producers lobbied U.S. government agencies to prevent importers from calling this product “catfish.” In American stores it is marketed as Basa fish or bocourti, also two unfamiliar names.

On top of cormorant predation, high production costs, low market prices, and foreign competition, American catfish producers faced another opponent with uncontrollable parameters – nature and the epic floods of 2011. Catfish farms along the Mississippi River Delta faced storm-driven waters which flooded roads, reduced feed supplies, topped their catfish pond levies, released their fish stock into the wild, and in some cases flooded their buildings. The damages and loss of production are yet to be tabulated, but surely what it means is, temporarily at least, catfish farming and production will be reduced even further.

So, all in all, what does this have to do with brutal, bloody sanctioned cormorant kills? Double-crested cormorants have little taste for corn or soybeans. They’re not grain-eating crows or geese; cormorants eat fish and have a predilection for catfish, particularly the penned-up, farm-raised variety. Fewer ponds produce fewer catfish – less winter chow for cormorants. The birds will have to return to foraging the Mississippi River and its tributaries for wild bluegills, perch, and wild channel catfish. And the whole package taken together means fewer healthy cormorants producing fewer healthy offspring.

Since the availability of food is a major limiting force for the expansion or contraction of wildlife populations an alternative then to government contract technicians killing tens of thousands of wild birds might be to let nature simply take its course. The birds wintering in the delta migrate from the northeast and mid-west so anything that places limits on their numbers in the South will send fewer cormorants to their traditional northern breeding grounds and cormorant populations may find newer, reduced numbers, naturally. And maybe the rifles and shotguns can be put away – at least for a while.

My book The Double-Crested Cormorant: Symbol of Ecological Conflict is now available in a trade hardcover version at Amazon.com, Barnes and Noble.com, and the University of Michigan Press, http://www.press.umich.edu/  which also offers an E-book edition. Also, check your local booksellers for availability. 

For insights into the book log on to my Author Page at www.amazon.com/author/dennis-wild .