Yesterday we reviewed the challenges that Jaguars have co-existing with the current practices of Cattle Ranchers in Guatamala, South America.........Today, we focus on whether "Reduced Impact Logging" can be compatible with the lifestyle needs of "El Tigre"(the Jaguar).......... "Reduced-impact logging" aims to ensure that strict standards are met during felling and removing timber".............. "This includes minimizing the number of roads constructed, avoiding sensitive areas and strictly regulating hunting".................. ""The presence of jaguars in a logging concession is testimony that environmental guidelines are being followed".........."Two recent Wildlife Conservation Society case studies from Guatemala and Peru indicate that certified logging operations can play an important role in maintaining vital habitat for jaguars and other large wildlife species"............"The bottom line is that certified, low-impact timber management by community groups and industrial operators constitutes one of the most effective jaguar conservation strategies available to jaguar-range countries"................ "Properly managed concessions help forests persist in the face of more intensive land uses, generate income for local stakeholders who become lead defenders of the forests, and maintain habitat for jaguars and their prey as they range beyond fully protected areas"

https://phys.org/news/2018-03-jaguars-well-managed-concessions-coexist-conservationists.html

Jaguars and well-managed logging concessions can coexist, say conservationists

March 22, 2018, Wildlife Conservation Society

Logging activities in biodiverse forests can have a huge negative impact on wildlife, particularly large species such as big cats, but a new study proves that the Western Hemisphere's largest cat species—the jaguar (Panthera onca)—can do well in logging concessions that are properly managed, according to conservationists from the San Diego Zoo Global and the Bronx Zoo-based WCS (Wildlife Conservation Society).

The study titled "Do responsibly managed logging concessions adequately protect jaguars and other large and medium-sized mammals? Two case studies from Guatemala and Peru" appears in the online version of the journal Biological Conservation. The authors are: Mathias W. Tobler and Samia E. Carrillo-Percastegui of San Diego Zoo Global; Rony Garcia Anleu, Gabriela Ponce Santizo, John Polisar, and Isaac Goldstein of WCS; and Alfonso Zuñiga Hartley of San Diego Zoo Global and Servicio Nacional Forestal y de Fauna Silvestre, Lima, Peru.

"Our findings indicate that certified logging operations can play an important role in maintaining vital habitat for jaguars and other large wildlife species," said Tobler, a scientist for San Diego Zoo Global and lead author of the study.

Much of the world's tropical forests have disappeared as a result of deforestation, particularly in biodiverse regions such as Central and South America that are home to jaguars, tapirs, peccaries, and many other charismatic species. Reduced impact logging operations, which strive to prevent uncontrolled hunting and other negative environmental impacts, provide conservationists with a sustainable alternative in multiple-use and/or buffer areas near core zones or fully protected areas.

To that end, the study research team initiated large-scale camera trap surveys to gauge the effectiveness of Forest Stewardship Council (FSC)-certified logging concessions in both Guatemala and Peru in maintaining terrestrial mammal communities, with a focus on jaguars. The camera traps in Guatemala's Maya Biosphere Reserve captured a total of 23 individual jaguars, whereas the traps in two concessions in Peru's Madre de Dios region recorded 43 of these big cats. The appearance of the same jaguar in two or more images can be determined from spot patterns that are unique to each individual; such "recaptures" are important for accurately determining jaguar densities.

The spatial capture-recapture models used to calculate jaguar densities in both certified logging concession locations estimated that the Guatemala site contained an average of 1.5 jaguars per 100 square kilometers, whereas the Peru site contained an average of 4.5 jaguars. Further, both sites supported more than 20 large and medium mammal species (with 22 in Guatemala and 27 in Peru).

"Controlling access into an area and hunting of prey are paramount considerations for the objectives of preserving biodiversity and ecological function, both of which are selling points for certified lumber products," said Dr. John Polisar, coordinator for WCS's Jaguar Program and a co-author of the study. "The presence of jaguars in a logging concession is testimony that environmental guidelines are being followed."

Polisar was the lead author in a previously published paper (in the journal Ambio) titled "Using certified timber extraction to benefit jaguar and ecosystem conservation." The study focused exclusively on jaguars (as opposed to jaguars and other large and medium sized species in the aforementioned paper) and explored the factors that contributed to the persistence of these big cats in certified forests in Bolivia, French Guiana, Nicaragua and Guatemala.

Studies assessing the environmental impacts of logging operations are crucial for saving wildlife, say study authors and other conservationists, who add that certified, low-impact timber management by community groups and industrial operators constitutes one of the most effective jaguar conservation strategies available to jaguar-range countries. Properly managed concessions help forests persist in the face of more intensive land uses, generate income for local stakeholders who become lead defenders of the forests, and maintain habitat for jaguars and their prey as they range beyond fully protected areas.

 Explore further: The problem of jaguars and space in western Paraguay

More information: Mathias W. Tobler et al, Do responsibly managed logging concessions adequately protect jaguars and other large and medium-sized mammals? Two case studies from Guatemala and Peru, Biological Conservation (2018). DOI: 10.1016/j.biocon.2018.02.015

"The jaguar is the largest cat in the Americas and historically was found from southwestern/southeastern USA to central Argentina".......... "Today, jaguars are an endangered species throughout their natural habitat, and have almost been completely eliminated from the United States".............. "Outside of the Amazon, they are present in only 20 percent of their original range"............ "This drastic change is a result of human factors: habitat loss leading to reduced prey availability and persecution for cattle depredation........'To illustrate the challenge the Jaguar has of making a living, it has been determined that in the South American Country of Paraguay, mean home range size for Jaguars is 818 km2 (310 sq. miles) in the Dry Chaco and 237 km2 (90 sq. miles) in the Humid Chaco/Pantanal"..........."In fact, with Paraguay deforesting 800 hectares a day(1840 acres) for beef cattle grazing, the Dry Chaco region has the largest home ranges ever recorded for Jaguars..........If you eliminate the Forest, you eliminate the Jaguar's prey,,,,,,,,,,,,,,As a result, they have to range far and wide to find their preferred food items of Capbara,Tapirs, Peccaries and Caiman--invariably running into domestic cattle and getting killed by the Ranchers who tend those herds

https://www.google.com/url?rct=j&sa=t&url=https://phys.org/news/2018-03-problem-jaguars-space-western-paraguay.html&ct=ga&cd=CAEYACoUMTI2NDUyODM0MjQ0NTI2MjM2MTYyGjNhZGZhMGEzMTRkNWEzYzc6Y29tOmVuOlVT&usg=AFQjCNF0RZ5bX0sKRx3z1OcRqsAIu6TlEA

The problem of jaguars and space in western Paraguay

March 21, 2018, De Gruyter

The jaguar is the largest cat in the Americas and historically was found from southwestern USA to central Argentina. Today, jaguars are an endangered species throughout their natural habitat, and have almost been completely eliminated from the United States. The species has been lost from 50 percent of its original range, and outside of the Amazon it is present in only 20 percent of its original range. This drastic change is a result of human factors: habitat loss leading to reduced prey availability and persecution for cattle depredation.

PARAGUAY BORDERS BRAZIL, PERU, CHILE AND ARGENTINA

DRY CHACO REGION OF PARAGUAY IN DARK GREEN

An important component of jaguar conservation is understanding the species' spatial needs. Although there have been multiple studies of jaguar space use, there has been no such research in Paraguay up to now.

 AS SWAMPS ARE DRAINED, A CAIMAN MEAL IS NOT AS 
AVAILABLE TO JAGUARS

A recent study, published in the journal Mammalia, shows how researchers used GPS technology and new analytical techniques to produce the first rigorous estimates of jaguar spatial needs and movements in the Gran Chaco and Pantanal ecosystems of Paraguay.

PECCARIES ARE DISAPPEARING FROM THE GRAN CHACO
ECOSYSTEM, A PRIME PREY ITEM FOR JAGUARS

Western Paraguay is dominated by the Gran Chaco ecosystem, the second largest forest ecosystem in South America (divided into the semi-arid Dry Chaco and the wetter, seasonally flooded Humid Chaco), but also contains 5 percent of the Pantanal ecosystem. The researchers found that jaguars in the Dry Chaco had the largest home ranges ever recorded for jaguars, attributable to relatively low productivity of the ecosystem. Also, regardless of the ecosystem type, jaguar daily movements were large, on average greater than 15 km per day.

CAPYBARA'S DWINDLING IN NUMBERS--JAGUARS TURNING
TO DOMESTIC CATTLE FOR PROTEIN NEEDS

Since 2000, western Paraguay has undergone some of the highest deforestation rates in the world with about 800 hectares a day on average of natural habitat converted for cattle production; allowing Paraguay to be the world's 6th largest beef producer.

RANCHERS ARE CUTTING DOWN WESTERN PARAGUAY
FOR CATTLE RAISING, DISPLACING THE PREY OF THE
JAGUAR

This ongoing land use change, and the large spatial needs of jaguar, means that jaguars are increasingly affected by human activities and subjected to retaliatory killing for preying upon livestock. This was evident in the study as greater than 50 percent of the jaguars followed in the study were confirmed to have been killed by people.

JAGUARS OR CATTLE?............CAN THE TWO COEXIST?

There is an urgent need to mitigate jaguar-human conflict in the region. Less than 5 percent of western Paraguay is protected; in light of continuing deforestation, conservation efforts must take into account the amount of space needed by jaguars in the region. Consequently, the long-term conservation of the jaguar in western Paraguay depends upon private land and diminishing conflict with the continuing expanding ranching sector.

 Explore further: Brazil scientists warn on dwindling jaguar population

More information: Roy T. McBride et al. Space use and movement of jaguar (Panthera onca) in western Paraguay, Mammalia (2018). DOI: 10.1515/mammalia-2017-0040

The Central american Country of Belize is following though on Nobel Winning Ecologist Edwin O. Wison's call to SAVE HALF EARTH by creating a 110 square kilometer(42 square miles) nature reserve to be known as the BELIZE NORTHEASTERN BIOLOGICAL CORRIDOR...................Here at home in the USA, the Country that developed the World's first National Park, EcoIogist Wilson challenges all of Americans to think equally as big as Belize.........He asks: "Is the caring for the environment a matter of being a Democrat or a Republican, a liberal or a conservative, a Christian, Jew, Muslim, Buddist or a non believer?"............ "Can preserving biodiversity be something that all of us can work toward together?" "May we forget for a while our metaphysical, religous and secular differences, lower the volume on the culture war, and meet on this common ground of saving the creation - that is saving biodiversity which is in such peril worldwide?".............."if we continue to the end of the century on our curent path of land alteration and degradation, it is likely that we will have exterminated about half of the known species of plants and animals".................. "Why let tis happen when the value of the services that ecosystems give us are unmeasurably positive"............. "The assemblages of natural living plants, animals, and microorganisms provide us with purification of water, the management of water reserves, pollination, the renewal of the soil, the purification of the air we breathe and half of our medicines and pharmaceuticals".............."Those services amount roughly to the total of the gross world product - that is all the combined national products of every Country in the world-- in the vicinity of $30 trillion!!!"...................And we get all of those ecosytems services scot-free!!!"................ "So that ought to be reason enough for not disposing of that biodiversity and trying to substitute at high expense the human contrivances that probably don't do it as well"............"Humanity must make a decision and make it now, right now!"............. "Conserve earth's natural heritage or let future generations adjust to a biologically impoverished world"..............."Large parts of nature are still intact — the Amazon region, the Congo Basin, New Guinea".......... "There are also patches of the industrialized world where nature could be restored and strung together to create corridors for wildlife"............."In the oceans, we need to let life there recover."............"The oceans are part of that 50% HALF EARTH that I propose be kept in their natural state"............... "This proposal does not mean moving anybody out of their homes"..........."It means creating something equivalent to the U.N.’s World Heritage sites that could be regarded as the priceless assets of humanity".................... "I offer this maxim: Do no further harm to the rest of life"------Edward O. Wilson, professor emeritus at Harvard University and recipient of two Pulitzer Prizes, the author of 30+ books on our natural world and humanity

https://www.google.com/url?rct=j&sa=t&url=https://news.mongabay.com/2018/03/belize-creates-one-of-central-americas-largest-biological-corridors/&ct=ga&cd=CAEYAyoTNzE5NTM0NjExMjYxNDYyNjQwNDIaNTI1NjVmODUzZjRjOTZmOTpjb206ZW46VVM&usg=AFQjCNFYhho55q9MnfIZOJ8UCxmCETv6wQ

Belize creates one of Central America’s largest biological Corridors

Shrey Dasgupta, March 19. 2018

• On Feb. 13, the government of Belize approved the 110-square-kilometer Belize northeastern biological corridor.
• The corridor aims to provide safe passage for wild animals like jaguars, pumas and Baird’s tapir to move freely between the Shipstern Nature Reserve and Freshwater Creek Forest Reserve in northern Belize.
• Private landowners have agreed to place their corridor-designated lands into a trust in perpetuity, with the lands to be managed as part of the protected area system for conservation purposes.

Belize is set to establish one of the biggest biological corridors in Central America,



connecting two nature reserves that are home to
jaguars and pumas, among other wildlife.

The Belize northeastern biological corridor, approved by the government on Feb. 13, will span some 110 square kilometers (42 square miles) of forest, according to a press release from the Corozal Sustainable Future Initiative (CSFI), a conservation NGO in Belize. It aims to provide safe passage for species such as jaguars (Panthera onca), pumas (Puma concolor) and Baird’s tapir (Tapirus bairdii) to move freely between the coastal dry forests of the Shipstern Nature Reserve and the tropical forests of the Freshwater Creek Forest Reserve.

“This corridor is highly important,” Heron Moreno, executive director of the CSFI, told Mongabay. “It will not only guarantee the long term survival of wildlife within the area but it will also contribute to the strengthening of the Belize Protected Areas System. Most importantly, it will serve to highlight the importance of Government, NGO and private partnership in conservation initiatives. This hereby paves the way and serves as a model for other similar initiatives to follow in Belize.”

A jaguar captured by a camera trap in Shipstern Nature Reserve. Photo courtesy of the Corozal Sustainable Future Initiative.

The push for corridors in Belize began about two decades ago through the Mesoamerican Biological Corridor Project, a Global Environment Facility-funded effort to interlink patches of forests from Mexico through Central America to Colombia. Belize’s northeastern biological corridor was one of the potentially important links that the project highlighted.

In 2015, the CSFI, together with other conservation NGOs, the government and private landowners reinitiated this dormant project, according to Caspar Bijleveld, secretary of the board of the CSFI and project coordinator for the group’s international partner, the International Tropical Conservation Fund (ITCF).

To decide the route of the corridor, the NGOs and the government used the general layout that the Mesoamerican corridor project had already proposed. “The route was originally one of the possibilities designated as such by the GEF project, back when the whole north-eastern part of Belize was forested,” Bijleveld said.

Two pumas caught on camera trap in Shipstern Nature Reserve. Photo courtesy of Corozal Sustainable Future Initiative.

However, expanding agricultural lands and other infrastructure development drove rampant deforestation around this route. So the teams cross-referenced the original proposed corridor with the actual forest cover on the ground to determine the final route of the corridor.

The next step was to convince the private landowners to give up their land for the corridor. That was challenging, Moreno said, because “the concept of corridors is still very vague and not quite proven to function as such.”

“To be able to engage the partners, it had to be tackled more from [an] economic and regulatory perspective,” he said, adding that the process did not involve any financial transactions.

A Baird’s tapir in the Shipstern Nature Reserve in Belize. Photo courtesy of Corozal Sustainable Future Initiative

Balam Jungle Estates, which owns the largest land parcel in the corridor, was convinced by tax incentives offered by the government. The Rheinländer Mennonite community, which owns another land parcel with the corridor, was convinced by a regulatory clause. “When they purchased the land, the Department of the Environment had imposed a clause of non-deforestation on the parcel that was recognized as a potential part of the corridor,” Bijleveld said.

Ocelot  in Belize forest

Both landowners have agreed to place their corridor-designated land into a trust in perpetuity. The land, which will continue to be owned by the private landowners, will be managed as part of the protected area system for conservation purposes. “This protected area can then de facto only be managed as such, according to rules defined by the Trust itself,” Bijleveld said. “The rules themselves will be based on national legislation on protected areas.”

For its part, the government will halt the collection of taxes on those lands for the duration of the trust arrangement, Moreno said.

Coyote in Belize woodland

The private landowners have yet to officially put their land into trust. “This is still much in process. Trust agreements have already been drafted but official signatures are still pending,” Moreno said.


Gray Fox in Belize woods

In addition, the government still needs to acquire some 40 square kilometers (15 square miles) of land within the corridor, at an estimated cost of about $1 million.

“ITCF is engaging with international NGOs active in the acquisition of lands for corridors and other critical habitats, asking them for their help,” Bijleveld said. “Although at this stage I am not in a position to cite names, things are looking promising.

“Personally, I have always been a firm believer that conservation success is a matter of long, if not very long-term involvement in a project,” he added. “That success sometimes comes through waiting for the right window of opportunity and having (lots of) patience. I have been involved in forest conservation in Belize for 30 years, and [it’s] successes like these that will keep me going for another 30.”

"New Research from the Smithsonian Tropical Research Institute in Panama, South America has revealed that starting 2500 years ago, the Maya(First Nations People) started bringing dogs, Wild Turkeys, Jaguars and Pumas to Ceibal, Guatemala from the distant Guatemalan highlands".........."Ceibal was an important Maya urban center with a nearly 2,000-year occupational history (1000 BC to AD 950), allowing for a long-term examination of animal-related activities".............."The possible ceremonial contexts of these captive-reared animals suggests Animal Management played an important role in the symbolic development of political power".............."Whereas "In Asia, Africa and Europe, Animal Management went hand-in-hand with the development of cities, in the Americas people may have raised animals for ceremonial purposes that may have played a significant role in societal development"

http://feedproxy.google.com/~r/sciencedaily/plants_animals/~3/E96ykqLK_A0/180319155742.htm?utm_source=feedburner&utm_medium=email

First evidence of live-traded dogs for Maya ceremonies

March 19, 2018; Smithsonian Tropical Research Institute

 Ashley Sharpe, an archaeologist at the Smithsonian Tropical Research Institute in Panama, and colleagues combined clues from carbon, nitrogen, oxygen and strontium isotope analysis discovering the earliest evidence that the Maya raised and traded dogs and other animals, probably for ceremonial use.

The Maya people started raising and bringing

domestic dogs and wild animals to Ceibal, Guatamala

for Ceremonial purposes some 2500 years ago

Their results are published in the Proceedings of the National Academy of Sciences during the week of March 19.

"In Asia, Africa and Europe, animal management went hand-in-hand with the development of cities," said Sharpe. "But in the Americas people may have raised animals for ceremonial purposes. The growth of cities doesn't seem to be directly tied to animal husbandry."

Sharpe found that animal trade and management began in the Preclassic Period some 2,500 years ago and intensified during the Classic Period, making it likely that organized ceremonies involving animal and human sacrifice and raising animals for food played important roles in the development of Maya civilization.

Isotopes are atoms that have the same number of protons and electrons but different numbers of neutrons and therefore have different physical properties. For example, carbon has two stable isotopes: carbon 12 with six protons and six neutrons and carbon 13 with six protons and seven neutrons. Carbon in animals' bodies comes from the plant tissues they consume directly or indirectly. Most plants use the most common type of photosynthesis to turn carbon dioxide into carbohydrates. This process leaves mostly the lighter carbon isotope, carbon 12, behind, bound up in carbohydrate molecules. Corn, sugar cane and other grasses use another type of photosynthesis that concentrates heavier, carbon 13 molecules. Nitrogen isotopes in proteins demonstrate a similar pattern.

Sharpe and colleagues analyzed the isotopes in animal remains from Ceibal, Guatemala, a Maya site with one of the longest histories of continuous occupation, and one of the earliest ceremonial sites. Most of the bones and teeth they tested were from the Maya Middle Preclassic period (700-350 B.C.).

"The animal remains fall into two categories, those with lower carbon isotopes, indicating they were eating mostly wild plants, and those with higher isotopes, which were probably eating corn."

All of the dogs, two northern turkeys, Meleagris gallopavo, the turkey species that was eventually domesticated, and one of two large cats were probably eating corn or other animals that fed on corn, such as a peccary (wild pig).

Because people in the region often killed animals that came into gardens and areas where crops were being cultivated, it is possible that peccaries and turkeys may also have been eating crop plants, but it is likely that turkeys were managed by the end of the Classic Period.

Deer bones showed butcher marks, but they were hunted from the forest, not domesticated according to isotope analysis of bones that also had lower carbon isotopes.

One large cat and a smaller cat, probably a margay, Leopardus wiedii, had lower carbon isotopes indicating that they ate animals that fed on wild plants.

The ratio of two strontium isotopes reflects the local geology in a region. Forty-four of the 46 animals had strontium isotope ratios matching Ceibal and the surrounding southern lowlands region. However, to Sharpe's surprise, jaw bones from two dogs excavated from deep pits at the heart of the ancient ceremonial complex had strontium isotope ratios matching drier, mountainous regions near present-day Guatemala City. "This is the first evidence from the Americas of dogs being moved around the landscape," Sharpe said. "Around 1000 A.D. there's evidence that dogs were moved out to islands in the Caribbean, but the Ceibal remains are dated at about 400 B.C." Part of the jaw bone and teeth of a big cat was found with one of the dogs in the same deposit.

"The interesting thing is that this big cat was local, but possibly not wild," Sharpe said. "Based on its tooth enamel, it had been eating a diet similar to that of the dogs since it was very young. Perhaps it was captured and raised in captivity, or it lived near villages and ate animals that were feeding on corn. We still have to look at the DNA to figure out if it was a jaguar or a puma."

Sharpe is looking forward to understanding more about the context of these finds. "The results in this publication are based on excavations we did in 2012. My colleagues at the Ceibal-Petexbatun Archaeological Project will publish additional analyses, and I'm looking forward to finding out if all of the human remains at the site are from the region."

"It's interesting to consider whether humans may have had a greater impact managing and manipulating animal species in ancient Mesoamerica than has been believed," Sharpe said. "Studies like this one are beginning to show that animals played a key role in ceremonies and demonstrations of power, which perhaps drove animal-rearing and trade."

Story Source:

Materials provided by Smithsonian Tropical Research Institute. Note: Content may be edited for style and length.

---

Journal Reference:

1. Ashley E. Sharpe, Kitty F. Emery, Takeshi Inomata, Daniela Triadan, George D. Kamenov, John Krigbaum. Earliest isotopic evidence in the Maya region for animal management and long-distance trade at the site of Ceibal, Guatemala. Proceedings of the National Academy of Sciences, 2018; 201713880 DOI: 10.1073/pnas.1713880115

Ruins of Maya Temple at Ceibel, Guatamala

Maya Dog figurine artifact

Mayan people

Mayan Jaguar figurine artifact

"It is estimated by esteemed Nobel-Winning Ecologist Edwin O. Wilson that only 2 of the 10 million species living on earth today are known"............"Paleontologists estimate that before the global spread of humankind, the average rate of species extinction was one species per million in each one- to 10-million-year interval"........... "Human activity has driven up the average global rate of extinction to 100 to 1,000 times that baseline rate"................"At this present rate of human caused extinction, it is estimated that we will eliminate more than half of all species by the year 2100"............."Wilson's solution to stop this biological genocide is called HALF EARTH".............."To reverse the extinction crisis, we have to enlarge the area of Earth devoted to the natural world enough to save the variety of life within it"............. "The formula widely agreed upon by Wilson and many other conservation scientists is to keep half the land and half the sea of the planet as wild and protected from human intervention or activity as possible"............. "Wilson's 'Island Biogeography Theory' states that the more isolated an ecosystem, the fewer species it supports"........... "Half EARTH would mitigate 'ISLAND ISOLATION OF SPECIES impacts by stitching together the largest natural areas left on the Planet via 'nature highways'----greenways that allow animals and plants to move freely back and forth carrying their genes and carrying out their ecological services functions across their bioregions"............."We should preserve every scrap of biodiversity as priceless while we learn to use it and come to understand what it means to humanity--source:. E. O. Wilson

CLICK ON LINK TO READ FULL ARTICLE
https://www.nytimes.com/2018/03/03/opinion/sunday/species-conservation-extinction.html

The 8 Million Species We Don’t Know

By EDWARD O. WILSONMARCH 3, 2018

Continue reading the main storyShare This Page

• Share
• Tweet
• EmaiMore

The extinction of species by human activity continues to accelerate, fast enough to eliminate more than half of all species by the end of this century. 

The worldwide extinction of species and natural ecosystems, however, is not reversible. Once species are gone, they’re gone forever. Even if the climate is stabilized, the extinction of species will remove Earth’s foundational, billion-year-old environmental support system. 

Land and Marine areas currently protected by law(no where near
HALF EARTH status

A growing number of researchers, myself included, believe that the only way to reverse the extinction crisis is through a conservation moonshot: We have to enlarge the area of Earth devoted to the natural world enough to save the variety of life within it. The formula widely agreed upon by conservation scientists is to keep half the land and half the sea of the planet as wild and protected from human intervention or activity as possible. This conservation goal did not come out of the blue. Its conception, called the Half-Earth Project, is an initiative led by a group of biodiversity and conservation experts (I serve as one of the project’s lead scientists). 

It builds on the theory of island biogeography, which I developed with the mathematician Robert MacArthur in the 1960s.Island biogeography takes into account the size of an island and its distance from the nearest island or mainland ecosystem to predict the number of species living there; the more isolated an ecosystem, the fewer species it supports. After much experimentation and a growing understanding of how this theory works, it is being applied to the planning of conservation areas.

So how do we know which places require protection under the definition of Half-Earth? In general, three overlapping criteria have been suggested by scientists. They are, first, areas judged best in number and rareness of species by experienced field biologists; second, “hot spots,” localities known to support a large number of species of a specific favored group such as birds and trees; and third, broad-brush areas delineated by geography and vegetation, called ecoregions.All three approaches are valuable, but applying them in too much haste can lead to fatal error. They need an important underlying component to work — a more thorough record of all of Earth’s existing species.  Making decisions about land protection without this fundamental knowledge would lead to irreversible mistakes. 

The most striking fact about the living environment may be how little we know about it. Even the number of living species can be only roughly calculated. A widely accepted estimate by scientists puts the number at about 10 million. In contrast, those formally described, classified and given two-part Latinized names (Homo sapiens for humans, for example) number slightly more than two million. With only about 20 percent of its species known and 80 percent undiscovered, it is fair to call Earth a little-known planet.

Paleontologists estimate that before the global spread of humankind the average rate of species extinction was one species per million in each one- to 10-million-year interval. Human activity has driven up the average global rate of extinction to 100 to 1,000 times that baseline rate. What ensues is a tragedy upon a tragedy: Most species still alive will disappear without ever having been recorded. To minimize this catastrophe, we must focus on which areas on land and in the sea collectively harbor the most species.