When temperatures drop, macaques often huddle together to pool their body heat, forming what’s known as a saru dango, or “monkey dumpling.” This behavior is common among the 23 species of macaques, all of which form complex matriarchal societies. It is especially important for Japanese macaques (Macaca fuscata), which live in colder climates than any other primate, aside from humans. On frigid days, their need for warmth clearly outweighs their desire for personal space.

Surrounded by black volcanic sands, a peacock mantis shrimp (Odontodactylus scyllarus) stands guard over her ribbon-like mass of fertilized eggs. The folds of this portable, flexible structure—held together with an adhesive produced by the mother—provide ample surface area for gas exchange between the egg membranes and the surrounding environment. The female cleans and aerates the developing eggs with the same appendages she typically uses to handle prey. With her limbs more than full caring for her brood, the female won’t eat until the eggs hatch and the larvae disperse.

To capture this view of a mother grizzly bear (Ursus arctos horribilis) and her cub, photographer Peter Mather set up a camera trap on a log that he knew the bears tended to traverse while fishing for salmon. Packed with both protein and fat, salmon provide grizzlies with a critical source of energy and nutrients during the spawning season. However, the fish can also carry high levels of environmental toxins, such as mercury, that put the bears at risk. Because mercury accumulates in the tissues of organisms and is passed along the food chain, top predators like grizzlies tend to be exposed to higher concentrations of the toxic metal. Indeed, scientists have found that some 70 percent of grizzly bears sampled along the coast of British Columbia over the past decade contained mercury levels above what is considered safe.

These elephant feet-turned-footstools are among some 1.3 million confiscated wildlife products housed in a U.S. Fish and Wildlife repository near Denver, Colorado. Despite bans on the international trade of products made from endangered species, such goods continue to find their way into illegal markets. Until recently, it was unknown whether these items were leaking out of repositories or coming from recent kills. To find out, researchers radiocarbon dated 231 ivory samples seized between 2002 and 2014. They found that only one of the samples was old enough to have come from storage, which suggests that persistent poaching continues to be the primary source of ivory goods. And the practice is taking a heavy toll. A recent census found that African elephant (Loxodonta africana) populations have shrunk by an average of 8 percent each year over the past decade.

The remote Revillagigedo Islands off the west coast of Mexico are actually the four highest peaks of a mostly submerged volcanic mountain range. In the surrounding marine sanctuary, cool waters from the North Pacific mix with the warm Northern Equatorial Current. This nutrient- and plankton-rich convergence attracts a diverse array of sea life—and the protections mandated by the sanctuary help to sustain an unusually healthy marine ecosystem. In this photograph, more than a thousand top predators, including dusky sharks (Carcharhinus obscurus), yellowfin tuna (Thunnus albacares), and Galápagos sharks (Carcharhinus galapagensis) work in unison to round up a shared meal of chub and other baitfish.

When farmers in West Bengal finish their harvest of wheat or rice, they often burn the straw and stubble that’s left behind. It’s a quick–if destructive and banned—way to clear the field and return some of the crop’s nutrients to the soil in preparation for the next season’s planting. The practice is also a boon to local birds. As insects flee the flames, birds like these black drongos (Dicrurus macrocercus) swoop in to take advantage of the bounty.

These beauties may appear to be single-celled organisms viewed under a microscope, but you’re actually looking at a bucket filled with dozens of by-the-wind sailors (Velella velella). Each sailor—measuring up to three inches long—is a colony of individual polyps that feed on plankton, reproduce, and defend the colony. These close relatives of jellyfish float on the surface of the ocean, their translucent triangular sails providing mobility. But like other sailors, they travel at the mercy of the wind, and occasionally end up stranded en masse along Pacific Coast beaches.

Since the 1960s, North American populations of snow geese (Chen caerulescens) have exploded an estimated thirteen-fold, in part because of the sprawling fields of grain that have cropped up along their migration route over the past 60 years. In Canada, the species has been officially declared overabundant, largely due to its impact on sensitive Arctic habitats. Descending in vast flocks, the geese leave a wake of mowed-down plants and exposed ground that can take decades to recover. The results can be devastating for other species, such as the endangered rufa red knot (Calidris canutus rufa), that rely on this vegetation for foraging and nesting habitat.

This past January, a steady stream of lava, called a firehose, suddenly gushed from an underground lava tube at the base of Hawai’i’s Kilauea volcano and spilled into the Pacific Ocean. As the molten rock met the cooler seawater, steam, sand, and chunks of cooled lava were thrown explosively into the air. The impact of these continual bursts of energy eventually created a crack in the 90-foot seacliff, which expanded over the course of a week until a section of the cliff broke off entirely and sloughed into the sea.

At the Hetaoping Research and Conservation Center in China’s Wolong Reserve, captive-bred giant pandas (Ailuropoda melanoleuca) have been raised with the hope of one day reintroducing them to the wild. To prevent young pandas from imprinting on and becoming attached to their human caregivers, the center’s staff wear costumes that mimic the animals’ characteristic black and white pattern. That pattern, which scientists have puzzled over for decades, is now thought to be an evolutionary compromise that allows pandas to blend into both snowy backgrounds in the winter and shadowy forests in the summer.

Photographer Franco Banfi and his fellow divers were following this pod of sperm whales (Physeter macrocephalus) when the giants suddenly seemed to fall into a vertical slumber. This phenomenon was first studied in 2008, when a team of biologists from the UK and Japan inadvertently drifted into a group of non-responsive sperm whales floating just below the surface. Baffled by the behavior, the scientists analyzed data from tagged whales and discovered that these massive marine mammals spend about 7 percent of their time taking short (6- to 24-minute) rests in this shallow vertical position. Scientists think these brief naps may, in fact, be the only time the whales sleep.