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Bats are members of the order Chiroptera, which is the second-largest order of living mammals. The geographic distribution of these flying mammals is tremendous as well, ranging from the limit of trees in the Northern Hemisphere to the southern tips…

The Hudson River estuary in the United States experiences a tide from New York Harbor (river kilometer 0/river mile 0) to Troy, New York (river kilometer 244/river mile 152). In the lower 60 kilometers (37 miles) of the Hudson River, the water is…

There is a growing body of evidence that many of the thousands of prescription and over-the-counter medications ultimately make their way into water bodies and drinking-water supplies. Typical wastewater treatment plants may not be effective at…

Microplastics are raining down on national parks and other protected areas in the western United States at the rate of about 132 pieces of microplastic per square meter every day, according to a report in the journal Science (June 2020).…

Wildfires, also termed bushfires or forest fires, are currently devastating large swaths of land in Australia. Detrimental ecologic consequences of these uncontrolled combustions of forest fuels and vegetation are numerous. One of the most serious…

The world’s oceans and coasts provide a natural sink for excess carbon in the atmosphere. Scientists refer to carbon that is captured and stored this way as blue carbon. Well-known blue-carbon examples include mangroves and salt marshes—wetland…

Using an artificial intelligence technique known as deep learning and high-resolution remote sensing, scientists have counted and mapped the location of trees in 11,000 satellite images covering more than 1.3 million square kilometers (500,000…

The earliest representatives of modern humans—those belonging to Homo sapiens—evolved from more archaic humans approximately 150,000–300,000 years ago in eastern Africa. During succeeding years, the geographical range of anatomically modern humans…

Life on Earth has been punctuated by a number of catastrophic mass extinctions throughout history. During these events, diverse taxonomic groups collapsed from the relatively rapid and widespread extinction of large numbers of species. Precipitated…

Conservationists are alarmed by significant reductions in insect populations worldwide. Based on recent biodiversity surveys and entomological studies, scientists estimate that more than 40% of the world's insect species (class Insecta, phylum…

Of the three extant elephant species, two inhabit Africa: the African bush or savanna elephant, Loxodonta africana; and the smaller African forest elephant, L. cyclotis. The African bush elephant is the largest living land mammal and is primarily…

All of the many diverse breeds of dogs, including both domestic and wild dogs (wolves, coyotes, foxes, jackals, and dingoes), belong to the genus Canis in the mammalian family Canidae. One intriguing example of an obscure wild dog is the New Guinea…

Scientists have identified the earliest known fossil of a modern bird. The fossil remains—comprising an almost-complete skull and a few limb bones embedded in rock—were discovered in a limestone quarry in Belgium. Estimated to be approximately 66.7…

Overwhelming fossil evidence of dinosaurs indicates that these reptiles inhabited terrestrial environments and were initially bipedal (two-footed). Then, as dinosaurs evolved, some became quadrupedal, walking on four legs. Other ancient nondinosaur…

The Tasmanian devil (Sarcophilus harrisii) is the world's largest living marsupial carnivore. For tens of thousands of years, this fierce animal could be found throughout the continent of Australia, as well as inhabiting the island of Tasmania.…

Many trees in forests worldwide rely on natural fires to create growing conditions necessary to perpetuate the ecosystem, or to stimulate germination. However, for more than 100 years, humans have been suppressing frequent natural low-intensity…

Persistent changes in the Earth's climate that have been occurring primarily as a result of human-caused greenhouse-gas emissions since the mid-twentieth century have led to significant increases in infectious diseases in wildlife, both in terms of…

The Joshua tree (Yucca brevifolia) is a remarkable evergreen, treelike plant found only in the southwestern United States. It was named by Mormon settlers in the early 1800s. Upon seeing the limbs of this plant branching upwards to heaven, the…

Collectively, members of the class Amphibia are facing massive reductions in total numbers, and the overall biodiversity of amphibians across the globe is under threat. Scientists have determined that global climate change and habitat destruction…

Sea-level rise is caused by adding mass (water) and heat to the ocean. The Antarctic ice sheet represents a potentially large source of water. Knowing the speed and direction (velocity) at which the Antarctic ice sheet is flowing to the ocean is…

Charles Robert Darwin (February 12, 1809 – April 19, 1882) is one of the most celebrated and eminent scientists of the past few centuries, with his broadest and most notable influence arising from his theory of evolution by means of natural…

It has been a long-held belief that, as a result of hunting habits, early humans were partly or even primarily responsible for the decline and eventual extinction of most of the largest mammalian species that inhabited ancient Africa. These large…

The critically endangered northern white rhinoceros (Ceratotherium simum cottoni) is a subspecies of white rhino that is on the brink of complete extinction, with only two individuals left in captivity and no known members reported in the wild. The…

The International Union for Conservation of Nature (IUCN)—the global authority on the status of the natural world—estimates that approximately 5–10% of the world's insect species (class Insecta, phylum Arthropoda) are threatened and facing…

At the Woranso-Mille paleontological site in northern Ethiopia, researchers have discovered a 3.8 million-year-old cranium (skull) belonging to a primitive hominin known as Australopithecus anamensis. Initially unearthed in 2016, but not reported…

All freshwater comes from precipitation over land, which is distributed on Earth as blue and green water. Blue water—that is, surface and groundwater—is stored as freshwater in lakes, streams, ice, and snow, as well as below ground. Green water is…

A report by a team of conservation biologists concludes that the total number of birds in North America has dropped precipitously since 1970. Annual surveys monitoring the biodiversity and abundance of bird populations across the North American…

Pesticides—including insecticides and herbicides—are chemical products used to control, reduce, or eliminate organisms that are harmful to cultivated plants. However, the use of pesticides on plants that provide foods for human consumption is often…

The golden jackal (Canis aureus) is the most widely distributed jackal in the world, populating widely diverse habitats across extensive ranges. In particular, this canine predator occupies large areas of northern and eastern Africa, the Middle…

Reusable sponge-like (foam) sorbent materials for cleaning up oil spills may soon become available, as a result of promising research from multiple groups. Oil spills damage ecosystems and habitats, harm and kill wildlife and plants, contaminate…

The Asian longhorned tick (Haemaphysalis longicornis), also known as the bush tick, is a troublesome parasitic species and is an important vector of disease agents. (Note that vectors are capable of biologically transferring a pathogen from one…

Colony collapse disorder (CCD) is a baffling detrimental condition in colonies of honeybees (Apis mellifera). It is characterized by a rapid loss of the adult bee population, with an absence of dead bees in and around affected colonies. No single…

Crown-of-thorns starfish or sea stars (Acanthaster planci; order Valvatida) are predatory marine invertebrates that feed on phytoplankton found on coral. They are native inhabitants of coral reefs in both the Indian Ocean and Pacific Ocean and are…

Conservationists have determined that the Bornean orangutan (Pongo pygmaeus) is disappearing much more rapidly than previously thought. Since 1999, the total number of Bornean orangutans declined by at least 148,000 individuals. The chief culprits…

The warming temperatures attributed to global climate change are making it more difficult for sea turtle populations to survive. As a result of the unusual developmental processes found in many reptiles, including some species of turtles, the sex of…

Sunscreens are polluting the ocean, and increasing evidence points toward some ultraviolet-light–absorbing chemicals found in sunscreens as being harmful to marine life—particularly corals at popular tourist destinations. While working toward…

The World Health Organization (WHO) is planning to recognize gaming disorder as a mental health disease in 2018. The 11th revision of the WHO's International Classification of Diseases (ICD), which is a major worldwide reference for epidemiological,…

The evolutionary transition of certain dinosaurs into modern birds has long been an active area of paleontological research. Because the members of the class Aves are living representatives of theropod dinosaurs, paleontologists have sought fossil…

In the fall of 2014 and early winter of 2015, an estimated 250,000 to 500,000 seabirds known as Cassin's auklets (Ptychoramphus aleuticus) died along the Pacific Coast from California to British Columbia, Canada. Researchers have now reported the…

Neonicotinoids (also termed neonics) comprise a class of insecticides and pesticides that chemically resemble nicotine. They are the most widely used insecticides in the world and are deployed by plant and crop farmers because these chemical…

Mammals possess a certain gene, termed PON1, which encodes a protein enzyme (paraoxonase) that is used to process the cholesterol lipids and fatty acids found in food. This gene evolved millions of years ago and is functionally active in terrestrial…

The Northern white rhinoceros (Ceratotherium simum cottoni)—one of two white rhino subspecies—is functionally extinct. Officially, this subspecies is classified by the International Union for Conservation of Nature and Natural Resources (IUCN) as…

Humans' contributions to global warming through burning fossil fuels and other actions (for example, detrimental land-use practices) have resulted in sharp increases in the levels of atmospheric carbon dioxide (CO2). These rising levels of CO2 also…

A newly identified reptilian fossil has pushed back the phylogenetic (evolutionary) family tree of Squamata [the dominant order of living reptiles, comprising lizards, snakes, and amphisbaenians (mostly limbless lizards that resemble worms)] by 75…

Scientists have long thought that dinosaur eggs were white in color and that the evolution of colored eggs in birds was strictly an avian innovation that occurred after the demise of the nonavian dinosaurs. However, technical advancements in the…

One notable study of predator-prey relationships, specifically between wolves and moose, has been conducted on Isle Royale since the late 1950s. Isle Royale is the largest island in Lake Superior. It was established as a national park in the United…

Quorum sensing is a process by which bacteria monitor their own population density by detecting the levels of signal molecules that are released by the bacteria. It is a unique phenomenon of cell-to-cell communication, enabling microorganisms to…

The Iberian lynx (Lynx pardinus; also known as the Spanish lynx), which inhabits the shrublands of southwestern Spain and Portugal, was on the verge of extinction at the beginning of the twenty-first century. At that time, this wild cat species was…

By July 6, 2018, beaches on the eastern coast of St. Vincent—an island located in the southeastern Caribbean Sea (Lesser Antilles)—were covered nearly one-meter deep with rotting brown algae (seaweed), known as Sargassum, posing multiple problems…

To better understand the nutritional effects (health benefits), chemical composition, growing conditions, and shelf life of microgreens, a team of researchers reviewed the science behind them in the Journal of Agricultural and Food Chemistry…