"If the laudable quest for survivors of the species proves not forlorn, we trust our boasted humanity will hold the protection of this beautiful bird to be a most sacred trust -- an attitude rarely taken in the day of its abundance."
So naturalist Albert Hazen Wright wrote in 1911, three years before the last of the Passenger Pigeon. The recent centenary of its extinction, for a bird that numbered in the billions in the 19th century and ended in oblivion early in the 20th century, brought forth much reflection and re-examination of our collective capacity and commitment to averting species' extinctions.
My colleagues who comprise the major bird conservation groups and the relevant federal and state agencies of the U.S. have a new "State of the Birds" report. The report focuses on the above theme, indicating how much we have learned and now apply to avert future avian extinctions.
The Passenger Pigeon's free fall from abundance still resonates. Periods of species abundance, as Wright noted, are when conservation measures should be considered.
Abundance is a phenomenon. It represents a neglected conservation value. Abundant wildlife inspires us, as it did when Passenger Pigeons darkened the skies flying over our new nation two hundred years ago.
Today, spectacles of abundance like aggregations of migratory geese or cranes, swarms of crows and blackbirds returning to their roosts, and "clouds" of shorebirds flying in tight formations, are among the abundance phenomena that stir the imagination. It is often the opportunity to experience such abundance, more than just seeing wildlife per se, that draws people to nature.
Sandhill Cranes are part of the massive "fly in" of abundant birds at dusk at New Mexico's Bosque del Apache National Wildlife Refuge. Photo by Steve Zack © WCS.
Abundance makes species' "role in nature" matter. Passenger Pigeons consumed the abundant hard nuts of the eastern forest, yet their copious dung left the emptied forests with fertile soil.
Today, bird species like Black-backed Woodpeckers respond in great numbers to western forest fires, feeding upon the bark beetles attacking wounded trees. The actions of woodpeckers include cavity creation, a resource critical to scores of small nesting birds and small roosting mammals. Vultures respond to carcasses rapidly and in large numbers, quickly consuming them and keeping pathogens like rabies at bay.
These "ecosystem services" provided by birds are only relevant if the species in question are numerous and occur widely. But abundance can mask vulnerability.
Many abundant or very common species are highly social. They breed and feed in dense aggregations. Passenger Pigeons were that way. Lesser Flamingos and Pinyon Jays, for example, are that way today and their sociability makes them more vulnerable than their population sizes would otherwise imply.
Birds' conservation status is better judged according to numbers of social units rather than by absolute population size. Even when highly social species are abundant, they remain vulnerable to threats to key breeding or feeding locales.
Lesser Flamingos are highly social and tied to shallow saline lakes, primarily in the Rift Valley of Africa. They are famously nomadic, moving unpredictably from lake to lake. They may be as numerous as three million, but are considered Near Threatened by the International Union for Conservation of Nature (IUCN).
Large numbers of flamingos died in Lake Nakuru a few years back, due in part to toxic poisoning from blue-green algae. Their primary locale for breeding, Lake Natron in Tanzania, is at risk for large-scale mining development.
The Pinyon Jay depends on the mast of pinyon pines in the Southwestern United States. Photo courtesy of Cole Wolf and Kristine Johnson.
Pinyon Jays share many traits of Passenger Pigeons. They depend on mast (food, in the form of plentiful, hard pinyon seeds) from pinyon pine trees in the Southwest and move great distances to find and feed on the mast. They breed at most any time of year amid new mast (seed cones), and cache these seeds in great numbers for later retrieval.
This latter behavior also benefits the pinyon pines, as unrecovered mast becomes a source of new seedlings for forest regeneration. An extended drought in the Southwest has greatly stressed the pinyon pines, killing large numbers of trees and greatly reducing the seed production. Their mast is disrupted and the very social Pinyon Jays are now at risk.
Conservation needs to be so much more than insuring that we secure species as if filling Noah's Ark with, as the Bible indicates, "seven pairs of every kind of bird, male and female..." We need a conservation ethos that embraces the importance of common and abundant species and the roles they play in nature, and to ensure that their abundance continues to inspire and engage us.