President's Corner | Sharyn Magee

President’s Corner: The Sixth Extinction

Conservation biologists Paul Ehrlich and Gerardo Ceballos have raised the alarm about the impending human driven sixth extinction in their book, The Annihilation of Nature: Human Extinction of Birds and Nature, a must read for anyone concerned about the loss of biodiversity, and in a formal paper in the journal Science. In the latter article Ceballos, Ehrlich, et al conclude that “The evidence is incontrovertible that recent extinction rates are unprecedented in human history and highly unusual in Earth’s history. Our analysis emphasizes that our global society has started to destroy species of other organisms at an accelerating rate, initiating a mass extinction episode unparalleled for 65 million years.”

I agree that the impending loss of biodiversity is the most serious aspect of the current ecological crisis and the most neglected by those in power. The loss of biodiversity is easy to overlook because populations die out slowly in in the human time frame, although quickly in the geological time frame. The loss of breeding populations is barely noticeable but as each population is lost, the species edges closer to extinction. Those of us who have been observing birds for decades notice a loss of numbers and of species but today’s diminished biodiversity seems normal to the young. Most ecosystems are resilient enough to adjust to the loss of a few species but as losses build up or a critical keystone species is lost, a point of no return is reached and ecosystems collapse, go through a period of chaotic instability, and reestablish themselves as less complex ecosystems with fewer species and interconnections. While no major terrestrial ecosystem has yet collapsed, several regional marine ecosystems have experienced ecosystem collapses resulting in a loss of vertebrate dominated ecosystems and their replacement with jellyfish dominated ecosystems, a simplified marine ecosystem that ruled the oceans over 300 million years ago.

Habitat loss and fragmentation is the prime driver of species extinction accounting for the unsustainable decline of more than seventy percent of the species at risk for extinction. Climate change and pollution exacerbate the problem by degrading habitats. The loss of biodiversity is universal. Tropical regions with their greater biodiversity are experiencing the greatest loss of numbers of individuals and species but temperate regions are suffering a higher percentage of loss. Migratory birds that rely upon temperate breeding grounds, tropical wintering grounds, and refueling and resting stops in-between are especially vulnerable. An astonishing thirty-seven percent of North American birds are at risk of extinction in the immediate future according to the 2016 State of North American Birds.

To reverse this loss, Dr. Ehrlich thinks that we should concentrate on populations, not species. By the time the species is threatened with extinction, only an expensive and time consuming sustained effort can reverse the decline and for many species heroic efforts are too late. Instead local populations should be identified and their habitats preserved to maintain a critical number of populations. This is where we can all help. Citizen Scientists are essential to identifying and monitoring local populations. The need is too great and the number of conservation biologists are too few to leave this job to professionals alone. EBird is an accessible way to contribute to the conservation effort, as is participating in the Christmas Bird Count, Bioblitzes, and other biosurveys. Once the relevant habitats are identified, conservation efforts can preserve and protect them. We are in a crisis but it is not hopeless. If each and every one of us does her or his part, we can still save many of the remarkable species with whom we share this planet. If enough species are saved, ecosystems remain intact.

~ Sharyn Magee

President, WCAS

Avian Intelligence

Recent studies in avian intelligence have shown that birds are much more intelligent than previously thought. Some bird families are now known to have brains that process information in a similar manner to the great apes and Parrots, Cockatoos, and Corvids have brain to body ratios that rival the great apes. The traditional linear ladder of intelligence with primates on top has been thoroughly debunked by rigorous cognitive studies of birds.

Corvids, parrots, and hummingbirds have given up songs for a complex vocabulary of calls that function as a language. Recent studies have shown that vocal learning occurs routinely in populations of wild parrots. Yellow-naped Amazons that roost together share a regional dialect of the “wa-wa” call with parrots that roost on the boundaries of two dialects, being bilingual. Dispersing juveniles learn the distinct   call of their new roost. In Australia Ringnecks and Galahs modify their contact calls to converge on the contact calls of conspecific flock members indicating socially driven vocal learning. Several species of parrots including Orange-fronted Parakeets and Spectacled Parrotlets have unique contact calls specific to individual birds in the flock. Female Budgerigars prefer bonding with males that use their specific contact call. As more species are studied, the evidence mounts that wild parrots have and know each other’s names.

Tool use has been reported among many avian species but New Caledonian Crows and Palm Cockatoos actually manufacture their tools. New Caledonian Crows make tools from either Pandanus leaves or sticks. The production of these tools requires multiple steps, indicating that the crow has a mental image of the tool before making it. The design of the Pandanus leaf tool varies regionally across New Caledonia in time and space indicating cultural transmission and social learning. In controlled experiments, New Caledonian crows have refashioned tools to solve problems. Male and female Palm Cockatoos cooperate to build a multilayered platform at the bottom of their nesting hole. Both sexes collect sticks, defoliate them, remove bark and side branches. The male breaks the sticks into the needed length by using his beak as a saw and then hands the stick to the female who splits it to provide a flat surface for the platform. Male Palm Cockatoos are the only non-human animal to make a tool to accompany their singing. The male fashions his drumming tool from a stick, adjusting its length to match his needs, and then drums the stick against a branch to accompany his vocalizations while fluffing up his feathers and raising his crest.   When a female appears, he extends his wings, inviting her to join him. Palm cockatoos are found in the Australian Cape York Peninsular and in the lowlands of New Guinea, but only the Cape York population is known to use the drumming tool, indicating that the behavior is cultural, not innate.

It is ironic that we are just learning about the amazing intelligence of many bird species at a time when thirty percent of all bird species worldwide and thirty-seven percent of North American birds are threatened with extinction. Because of their highly adaptable behavior and preference for open habitats or forest edges, most corvid species are stable, but species that have specialized habitat requirements or restricted ranges are in trouble. Persecution by humans in agricultural areas remains a problem and corvid numbers are declining where agricultural is spreading. Parrots and Cockatoos are among the most threatened avian families due to habitat destruction and capture for trade. Parrots are vulnerable to the loss of fruiting trees, especially in the tropics where they rely on a succession of fruiting species, and to the elimination of nesting sites, particularly where they require old growth trees for suitable nesting holes. Because of their beauty and intelligence, parrots are among the most sought-after birds for the extensive illegal bird trade. We are losing these magnificent creatures just as we are beginning to truly know them.

~ Sharyn Magee

President, WCAS

 

A Spring of Hope

It is a time of discontent for those of us who love the natural world. It seems every day brings a new threat to the environment and concern that the natural world itself is under siege. Our best efforts to protect the land and its inhabitants that we cherish seem to be for naught. Rather than despair at the present circumstances, this is a time to step back and celebrate what we love about the natural world. Only this gives us the strength to continue fighting for what we love.

As I write this, spring is approaching; it is a time of renewal, a time of hope. Already the buds are swelling on the maple trees, bringing the promise of the renewal of life. My resident birds who have clung to my feeders all winter, are now dividing their time between my feeders and the trees, where they hunt for the small insects that emerge with the opening of the buds. The male birds who have co-existed at the feeders all winter are becoming feisty. Already the dominant titmouse is chasing away potential rivals and has begun to sing. While two or more pairs of cardinals are still peacefully occupying the hedge nearest the feeders, the alpha male will soon assert his dominance, joining the Carolina Wren and titmouse in a growing spring chorus that will greet the coming of dawn around the world, reminding us that life is not so easily suppressed.

The Great-horned Owls are nesting, the earliest species to do so. The males are nest guarding this time of year. If you stumble upon one in the woods, he will stare you down with his yellow eyes, daring you to challenge him. He is the guardian of his realm, a fearless top predator, and he knows it.

Already the first migrants are headed north, following an ancient instinct that has survived the waxing and waning of glaciers. Soon the Long-eared Owls wintering in evergreen groves near open fields, will grow restless and start to move. Only time will tell if any of this threatened species stay and nest in the more secluded of our evergreen stands or depart with our winter visitors, the Yellow-bellied Sapsuckers, Brown Creepers, Winter Wrens, and others who have graced our woods, hedge rows, and fields this winter. The Pine Warbler, first of the wood warblers to nest in our area, will soon be singing at Baldpate and in the Institute Woods. Wintering in the southern states and barely into the Neotropics, Pine Warblers arrive at their nesting ground in late March. Louisiana Waterthrushes are the next to arrive in mid-April. They need to fledge their young before the streams, which support the invertebrates they feed to their young, dry up. Other species follow in late April and early May as the stream of migrants that began as a trickle becomes a torrent. Life, following ancient instincts, struggles onward.

The skunk cabbage has already bloomed. As the forest floor warms up and before the trees leaf out, spring ephemerals, among our most beautiful and delicate wildflowers, will bloom. Bloodroots, Trilliums, Hepaticas, and Virginia Bluebells give us reason to look down, as well as up, in the early spring. The Mourning Cloaks, the first butterfly of the year to be seen in the woods, appear concurrently. Baldpate Mountain and the Sourlands are strongholds for these species, yet another reason to fight for the ecological integrity of these lands.

While this is a time for vigilance against the many threats to the natural world, it is not the time to despair. There still remain places of great beauty brimming with wondrous life. Go out this spring and celebrate the world around you. It will give you the courage to fight for what you cherish.—Sharyn Magee, President, WCAS

 

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