Category: Animalia

All animals and general biology

Alpha in a Wolf Pack is a Fallacy

Grey Wolves
Photo: Dušan veverkolog (Unsplash, CC)

At dawn in Yellowstone’s Lamar Valley I had my first and only glimpse of a pack of wild grey wolves, but they always loomed large in imagination. I follow them in books and movies, read about their conservation and reintroduction, and in a more contemplative mood see their shadow in my pets.

We hold ambiguous attitudes. We created stories of them as evil predators but also learned they are faithful mates and parents. One of the enduring myths is that a pack is ruled by an alpha male and female.

The notion of a pecking order in social animals began with chickens! Such an appealing theory, the biologist Rudolf Schenkel adopted it back in 1947 to explain the hierarchy he observed among ten wolves cooped up in an enclosure at Basel Zoo.

Human societies organize vertically according to rank or class and historical upheavals trying to level differences to the horizontal never lasted long. I experienced the bottom of the pecking order in the school playground as a new boy tortured on the ‘bars’ (iron railings) by bullies who hazed/ initiated us. The great ethologist Konrad Lorenz in seeking to understand human aggression projected it forward from the behavior of animals, although I wonder if we misinterpret animals by extrapolating backwards from our behavior!

Animals, it is said, avoid inevitable conflicts of a homogeneous society by creating social ranks, disturbed occasionally by a strong rival for the alpha post. But this attractive theory fails the test of wilderness evidence in wolves, although even experts find it hard to break the habit of referring to alphas in a pack.

Dave Mech is a world expert who has studied wolves for decades. In Ellesmere Island in the Canadian high arctic he got on intimate terms with them where they are fearless of humans. He learned a wolf pack is not an assorted mix of related and unrelated animals, as in captivity. Each is a family consisting of a monogamous pair of adults and their pups, sometimes with adolescents tagging along. Since we don’t regard our parents as alpha adults, neither should we think of wolves in that way.

The dark side of the error of believing that pack leaders violently rule over subordinates is when it is applied to the training of dogs.  Owners who harshly punish pets for disobedience or insubordination may achieve their goal by intimidation, but at what price? Much better and more faithful to what we now know from wolves, we should be head of the family, Mom and Pop to our pups. Likewise, professional trainers today prefer to reward dogs for being a good boy or girl through positive reinforcement (operant conditioning).

Studies in Norther America and Europe should have packed off the creaking theory. But in biology there always exceptions, and not just those unhappy creatures in a cage. Evidently, pecking orders can exist in unusually large packs and maybe I saw a spectrum from alpha to omega when the morning mist cleared over the Lamar River.  

Next Post: Downy Woodpecker

Virginia is for Oyster Lovers

“Why then the world’s mine oyster, which I with sword will open.” Thus, Shakespeare gave us a new idiom in the Merry Wives of Windsor repeated ever since, and Oscar Wilde wielded it with customary wit: “The world was my oyster, but I took the wrong fork.”

It means a person expects to avoid adversity and find opportunity, like the discovery of a precious pearl. But if you asked an oyster it wouldn’t sound optimistic. Our excessive love kills them, and few cared about the relentless harvest until recently. In the poem recited by Tweedledee and Tweedledum, Alice felt sorry for oysters as the Walrus and Carpenter gobbled them on the beach.

Had we been aboard the shallop steered by the first English explorers of the Chesapeake Bay in Shakespeare’s day we would have been gobsmacked by an abundance of oysters, some as large as dinner plates and forming reefs grown close to the surface.  In 1701, a foreign visitor wrote in astonishment: “whole banks … ships must avoid them … four times as large (as English oysters) … I often cut them in two to put them in my mouth.”

The Bay was drastically impoverished by dredging its bed barren in the 19th century Oyster Rush.  The local economy collapsed and watermen switched to crabbing to make a living. The crash drastically impacted other fauna and flora since the remaining 2% of original numbers now took a year to filter the entire Bay which used to be achieved in a week. It is a classic example of the folly of free-for-all harvesting of a seemingly inexhaustible natural resource. Oyster beds are now making a slow recovery against a tide of agricultural effluent and disease, but helped by volunteers for the Chesapeake Bay Foundation and less harvesting pressure as oysters are cultured commercially.

If they are on your menu today, imagine the same shells on your plate again. The suggestion is ridiculous, but the point is that some restaurants in our region recycle shells for building wild oyster beds and embedding in artificial reefs. At one time, they were used as lime for mortar and roads, but when that became redundant they were dumped in landfills, so the recycling program is positive in every way.

oysters in Chesapeake Bay
Oysters shells curing in the sun

Shells are trucked to a depot in Maryland or the Virginia Institute of Marine Science beside the York River. A volunteer tips them on a hopper for conveyance through a tumble washer and bagging to cure in the sun for a year, eliminating the last traces of condiments from your meal. The happy, hot and sweaty team beside the river is, alas, not reassembling this year because of the coronavirus contagion.

oysters in Chesapeake Bay
Oyster gardening

Cured shells are loaded in tanks of brackish water to which larvae (‘spat’) are introduced from external suppliers. The spat can attach to hard surfaces like stone or concrete, but they prefer old shells, like the reefs of old. Young oysters are then dropped in sanctuary areas of the Bay or its creeks and rivers or oyster gardeners raise them for a year in cages where they grow faster and are protected before reaching their final destination. The goal is to deposit 10 billion oysters by 2025, an effort requiring over 21,000 hours of volunteer time.

oysters in Chesapeake Bay
Oyster lovers beside the York River

Not only will future diners and watermen benefit but the whole ecosystem. It is a story of a keystone species. In purifying 50 gallons of water a day, each oyster reduces dissolved nitrogen and phosphorus and, hence, the risk of dead zones from algal blooms. Their colonies provide important habitat for fish and crabs too. The early explorers adopted the Algonquin name for Chesapeake, meaning great shellfish bay,  and perhaps one day it will be apt again.

About Giant Eggs & Double Yolks

This week’s gift from a neighbor’s chicken coop included one extra-large egg. After hard-boiling and cracking open we found a double yolk, which some say is a good omen on our wedding anniversary. The following conversation over a meal would be unlikely in most homes, but perfectly natural in ours.

“Have you ever seen a giant human egg?” I asked my wife, Lucinda Veeck. I have only had a few hundred eggs under my microscope, but Lucinda has examined tens of thousands over a long career in her IVF lab.

Chicken egg with double yolkShe said it happened once. It was obviously immature because there were two nuclei in a cell enclosed by a membranous ‘box’ (the ‘zona pellucida’). A normal egg contains one nucleus and it vanishes shortly before ripening at ovulation by ejecting a surplus set of chromosomes in a cytoplasmic bleb. This elimination is so a fertilizing sperm can add a matched set to restore the pair.

Now here’s the thing. Her giant egg was not a microscopic version of the cooked egg. If a hen bird ovulates two yolky eggs simultaneously, which happens occasionally, they are quickly bathed in albumen, then enclosed in a common membrane and a shell during their journey down the oviduct, a process that takes about 24 hours to laying. As the nuclei are in separate yolks, the outcome is a normal genetic makeup with two chicks hatching from the same egg, although the cramped space affects their viability . The closest parallel is when non-identical human twins are conceived after a double ovulation.

But the nuclei in Lucinda’s giant shared the same cell, so their DNA would be inherited together. Had it been mature for fertilization the embryo would likely have three sets of chromosomes (two female and one male), called digynic triploidy, and fail to develop.

We explored explanations for its origin. If you have seen densely packed eggs in biopsies of young human ovaries you might wonder how they manage to grow independently instead of being swayed by neighbors, like people jostled in a football crowd. Sometimes they lose autonomy. I have seen two or more eggs combined inside follicles of every species examined, up to 14 in dog ovaries, although some looked unhealthy from the competition.

When boxed inside their own membrane eggs can’t fuse to make giant eggs. They have unique genetic makeups, just like eggs from separate follicles that go forward to make non-identical twins. But what happens when they coexist in a ‘box’ and don’t fuse to form a single cell?

Lucinda saw an example five days after an IVF procedure. It was a double embryo at the blastocyst stage with about 64 cells each. If separated for implanting in the womb, it seemed likely they could make non-identical twins, but if they had originated from a fertilized egg that had split instead of from two separate eggs they would make identical twins. It’s possible that they could unite (or reunite) to make a singleton pregnancy, and, if originating from two fertilized eggs, the baby would inherit mixed genetic lineages, a known condition called chimerism.

In the interests of being (somewhat) intelligible, I avoided more abstruse explanations and outcomes. With so many ways that development can go awry, it is a marvel that we turn out well, or mostly, and I am thankful for my genesis otherwise you wouldn’t be reading this post. I usually avoid writing technical stuff, but correspondence is welcome from readers who like to crack eggs.

Next Post: The Sound of Noise & Silence