Contends “compassionate conservation” is most effective protection of biodiversity
SYDNEY, Australia––The conservation establishments of both Australia and Israel might like to designate Arian D. Wallach an “invasive species” and slate her for extirpation.
Indeed, Wallach’s arguments could eventually put the entire global industry of exterminating “invasive species” out of business.
Like any successful adaptive species, however, Wallach appears to be seeding her iconoclastic perspectives successfully in leading peer-reviewed scientific journals throughout the English-speaking world, authoring or co-authoring published papers in recent years at the rate of about one per six weeks.
Having previously studied and taught at both the University of Adelaide, Australia, and the University of Haifa, Israel, Wallach now chairs the Centre for Compassionate Conservation in the School of Life Sciences at the University of Technology in Sydney, Australia.
What is “compassionate” conservation?
The very term “compassionate conservation,” popularized by Marc Bekoff, professor emeritus of ecology and evolutionary ecology at the University of Colorado in Boulder, is in itself a challenge to conservationists steeped in the hunting-focused traditions of gamekeeping and predator control.
But emphasizing the “compassionate” in “compassionate conservation” tends to miss many of the most important points that Wallach, Bekoff, and other “compassionate conservationists” make.
For starters, their approach to conserving biodiversity is much more practical and attainable in the real world than is “conservation” as conventionally practiced.
The Garden of Eden
Traditional conservation tends to be deeply rooted, if largely unawares, in the religious notion that there once as a perfect Garden of Eden, ordained by God but destroyed by mankind. Traditional conservation therefore seeks to protect biodiversity by deciding what species “belong” in any given place, as positioned by God or a “nature” exclusive of human activity.
Any species whose presence might challenge the ordained “natives” are thereafter persecuted as “invasive,” even if the habitat has changed so much that the “invasive” species are better suited than the “natives” to surviving there.
Wallach goes entirely the opposite way.
“Introductions have increased megafauna richness”
With Erick Lundgren of Arizona State University, Wallach in August 2017 produced a study published in the journal Ecography which, as a media release summarized, “shows that introductions have significantly increased megafauna richness, numerically replacing many of the Pleistocene megafauna that were lost around 50,000 years ago.
“Of the world’s 76 existing megafauna species,” Lundgren and Wallach wrote, defining “megafauna” as terrestrial species weighing more than 200 pounds, “22 have introduced populations, of which almost 50% are either threatened or extinct in their historic native ranges.”
“Critical buffers against extinction”
Said Wallach, “This study challenges fundamental ideas surrounding ‘invasive species’ and shows that the redistribution of species is ‘rewilding’ the world. The global decline of megafauna is driven by habitat loss, changes in land-use, and overhunting. Despite this, some megafauna have found refuge in new habitats through introductions.
“These populations are likely critical buffers against extinction,” Wallach offered. Lundgren and Wallach argued that Australia––and the world––benefit from the contributions of feral water buffalo, sambar, brumbies (wild horses), “and the world’s only population of wild dromedary camel, extinct in their native range” for 3,000 to 5,000 years.
“As large herbivores,” explained Lundgren, “these introduced species can consume plant matter indigestible to smaller herbivores, which may reduce fire frequency, accelerate nutrient cycling, and shape plant communities.”
Wallach, Lundgren, and additional co-authors struck again in the April 27, 2018 edition of Conservation Biology.
“A significant proportion of Earth’s wildlife has been erased, not from the world, but from our collective depiction of nature,” Wallach et al protested. “Even the most noticeable animals, terrestrial herbivorous megafauna, have been made nominally invisible. Wildlife outside native ranges are conspicuously missing from conservation data sets, distribution maps, population estimates, and conservation statuses.”
Nonetheless, Wallach et al wrote, “Introduced megafauna are a wonder of the Anthropocene,” meaning the time during which humans have been the dominant species on Planet Earth, “hidden in plain sight.
“Many regions have an immortalized moment ‘when the first white man stepped off the boat,’ heralding the beginning of Western civilization and the end of nature,” Wallach et al observed. “Organisms caught in humanity’s globalization currents were branded products of man, not of nature. Conservation databases depict Australia as empty of megafauna, despite being home to eight species, because they became established after James Cook landed at Botany Bay in 1770.
“A similar number of species are excluded from formal accounts of North American megafauna because they arrived after Christopher Columbus.
“All continents have more megafauna species today than in the Holocene”
“Valuing only ideals of untouched wilderness excludes much if not all the biosphere, perpetuates colonial ideologies, and fails to acknowledge thousands of years of human ecology exploitation,” Wallach et al emphasized.
The bottom line, despite much reckless talk of an “extinction crisis,” Wallach et al pointed out, is that “All continents have more megafauna species today than in the Holocene. Humans are implicated in the Pleistocene megafauna collapse,” meaning the loss of such species as the wooly mammoth, giant ground sloth, and saber-toothed cat after the most recent Ice Age, “and in the current decline of 60% of extant species within native ranges,” Wallach et al acknowledged. “Yet humans have also increased megafauna richness to levels approaching the Pleistocene, through redistribution and rewilding.”
Among other examples, Wallach et al cited “The small population of Colombian hippopotamus, descendants of ‘cocaine hippos’ who escaped the abandoned hacienda of Pablo Escobar,” whose numbers are growing despite attempt to sterilize and shoot them out of existence.
“Ignoring introduced species hides rewilding successes”
“Several species have proven resilient to control and now exist mostly or solely in the diaspora,” Wallach et al noted. For instance, the International Union for Conservation of Nature “lists wild horses as surviving only in Mongolia,” the one place where horses may exist who never had domesticated ancestors, “even though hundreds of thousands are also found across North America, Australia, South America, and Europe.”
Warn Wallach et al, “Ignoring introduced populations hides not only rewilding successes but also conservation and animal welfare harms. Over 300 native mammals are threatened by the wildlife trade,” including donkeys.
“Both feral and domestic populations, around the world, are rapidly being lost to slaughter to supply a fad demand among devotees of Chinese traditional medicine for ejiao, a gelatin made from donkey hides.
“Meanwhile,” wrote Wallach et al, “their predomestic ancestor,” the African wild ass, has a population of 50–200 mature individuals. Protecting this native population is paramount, but to ignore or even beget the extinction of their postdomestic relatives may extinguish any wild future for this animal.”
“It is possible to protect brumbies without abandoning takhis”
“Protecting megafauna in their introduced range can supplement rather than supplant existing conservation efforts,” Wallach et al contended. “It is possible to protect brumbies and mustangs without abandoning takhis,” better known as Przewalski’s wild horse.
“Accepting introduced megafauna as part of nature would enable more accurate threat assessments and informed policy,” Wallach et al believe, an argument which should appeal to governments trying to contain the cost of preserving endangered and threatened species.
“If species were assessed across their full range, six megafauna” now considered endangered or threatened in their “native” habitat “would be globally delisted,” or at least downlisted,” Wallach et al say, “which would reduce the number of threatened megafauna by about 13%.”
Also in April 2018, Wallach published a more regionally specific article, “Is the prickly pear a ‘Tzabar’? Diversity and conservation of Israel’s migrant species,” in the Israel Journal of Ecology & Evolution.
[“Tzabar,” Hebrew for “cactus,” is also a slang term used to identify native-born Israelis.]
“Populations introduced outside their native ranges (‘migrant species’) have commonly been viewed as a threat to be addressed with lethal control programs,” Wallach opened. “Israel has a long history of anthropogenic changes, and conservation has typically focused on ameliorating direct human impacts, rather than eradicating migrant species.
“This may be changing,” Wallach warned, “with the growing influence of invasion biology worldwide.”
Among 321 animal and plant species found in Israel, Wallach and fellow researchers found that “After accounting for local extinctions, immigration has increased Israel’s plant and vertebrate richness by 104 species.”
Yet, Wallach continued, “Israel’s immigrants [species] are increasingly being viewed from an invasion biology perspective,” having been described as “invasive” in 76% of the studies published in the past decade that involve those species.
“In some regions, particularly islands,” Wallach noted, “conservation is focused almost exclusively on controlling and eradicating migrant species. Australia declared a ‘war on cats’ in 2016 with the aim of killing two million wild cats by 2020. New Zealand aims to eradicate all migrant predators by 2050. The European Commission brought into law a regulation on migrant species, which obligates member states to control wildlife considered ‘invasive.’”
“Local species richness remarkably constant for past century”
Yet, Wallach maintained, citing many sources from other peer-reviewed published studies, “The majority of migrant populations are not known to have caused the types of effects that would justify” such responses, “and many have effects viewed as beneficial. In a world considered to be in the midst of a sixth mass extinction, it is notable that local species richness (biodiversity) has remained remarkably constant for the past century across the globe, in part due to migrant species replacing local extinctions. Heightened levels of biotic migration in the Anthropocene could be acting as an important adaptation mechanism to rapid change, and a countercurrent to extinction.
“Even where populations of migrant species have unwanted impacts,” Wallach pointed out, “control and eradication are often impractical. Most migrant populations cannot be eradicated, and therefore lethal control programs typically have no end point.
“Killing wildlife may drive increased densities”
Further, Wallach added, “Killing wildlife does not necessarily result in population declines and may even drive increased densities,” as animals and plants breed back up to the carrying capacity of the habitat.”
For example, Wallach mentioned, “Lethal control of wild cats in Tasmania, Australia, resulted in increased densities [of cats], probably due to surviving cats colonizing vacant territories,” as documented in a 13-month study by Tasmanian Department of Primary Industries biologist Billie Lazenby and two colleagues.
Control programs often backfire
“Suppression or eradication of migrant populations has also triggered ecological cascades that create further harms. The eradication of cats from offshore islands of Australia and New Zealand,” Wallach noted, “led to population increases of rabbits and rats, harming native vegetation and birds.”
Further, Wallach explained, “Even where threatened native species have increased their population size following lethal control of migrant species, recovery has not been lasting,” because of other changes in the habitat. Indeed, Wallach observed, “Native species can be harmed by efforts to control migrant species upon which they have developed ecological dependencies.”
For example, Wallach wrote, “An intensive control program of hybrid Spartina in San Francisco, USA, did not benefit the targeted native vegetation, and caused a significant decline in an endangered bird (California clapper rail) that uses the tall, dense grass for cover and nesting.”
Parakeets & nutria
Among feral species now established in Israel whose “new populations provide opportunities for ongoing evolution and speciation,” Wallach mentioned the Alexandrine parakeet and nutria.
“Israel’s immigrant nutria population has persisted for over five decades, and has even developed a uniquely long tail,” Wallach said.
“The contribution of immigration to biodiversity in Israel is consistent with patterns worldwide,” Wallach continued.
Citing other researchers, particularly University of Georgia Institute for Ecology assistant professor Dove Sax, Wallach observed that “Across the world’s island ecosystems,” where migrant species purportedly most challenge “native” species, “migration has doubled plant richness, tripled freshwater fish richness, and stabilized bird richness. Migrants have increased vascular plant richness from about 2,100 to 4,100 species in New Zealand, and from about 1,200 to 2,300 species in Hawaii.”
Cane toads trigger adaptation
Even “The introduction of cane toads to Australia,” among the most publicized of alleged biological “invasions,” Wallach noted, “has triggered rapid behavioral and morphological adaptation [of native species] to their toxins, enabling native predators to recover from initial declines. Rapid evolution has also occurred in Hawaii’s native birds in response to the introduction of avian malaria and its mosquito vectors, enabling some species to recolonize low-elevation disease-prone regions.
“Our study has shown that migration can contribute significantly to regional species richness, and to the survival of some species, to the extent that even a highly urbanized and populated country like Israel is increasing in plant and vertebrate richness.”
Contended Wallach, “Redirection of conservation attention from direct human impacts to immigrant species is at best a distraction. It is easier, after all, to cut down ‘invasive’ trees, than to protect Israel’s remaining open spaces from human expansion and consumption.”
“First, do no harm”
Wallach concluded “Is the prickly pear a ‘Tzabar’?” by outlining what she and others, including Bekoff, consider to be the four cornerstones of “Compassionate conservation”: “First, do no harm, individuals matter, valuing all wildlife, and peaceful coexistence.”
Debating these points is essentially debating philosophy.
From a hardnosed, practical, traditional conservation perspective, the question should supposedly be whether any given strategy actually achieves the intended result.
Restoring Eden won’t happen
If the intended result is restoring the Garden of Eden, even in small and intensively protected sanctuaries, that just is not going to happen. Apart from the realities of global warming and climate change, the continents of today––and even their locations on Planet Earth––are no longer what they were when many of the species evolved that are now the subjects of intensive conservation efforts.
Simply put, those species’ “native habitat” does not exist, has not existed in many hundreds of millennia, and cannot be recovered with any amount of effort.
But if the intended result is preserving and increasing net biodiversity, “compassionate conservation” demonstrably accomplishes this much more efficiently than attempts to kill our way to nirvana.
As Wallach concluded her “prickly pear” paper, “Conservation is ultimately less about how we think the world should be, and more about the manner in which we should engage with the world.”