Deep in the Ecuadorian Andes, an ancient forest stands as a final sanctuary against the encroachment of human activity. This is the Yanacocha Reserve, the last refuge for the Black-breasted puffleg (Eriocnemis nigrivestis), a tiny hummingbird teetering on the edge of extinction.

Measuring just 9 centimeters (3.5 inches), this emblematic bird of Quito is one of the most threatened species on the planet. According to the International Union for Conservation of Nature, its global population has dwindled to between 150 and 200 birds.

When big winter storms move in, they can bring nasty weather that ranges from snow to sleet and freezing rain — or maybe extreme and dangerous cold.

Here's a look at some weather conditions and how they vary from place to place.

Chile is reeling from one of its most serious wildfire emergencies in years.

Deadly flames sweeping across central and southern parts of the South American country have turned large swaths of forest and towns to ash, killed at least 20 people, forced tens of thousands from their homes and left families sifting through charred debris.

By Mireille Rebeiz, Dickinson College and Josiane Yazbeck, Université La Sagesse

(THE CONVERSATION) More than a year after a ceasefire nominally ended active fighting, much of southern Lebanon bears the ecological scars of war. Avocado orchards are gone and beehives destroyed. So, too, are the livelihoods they supported. Meanwhile, fields and forests have disappeared under the intense fire caused by white phosphorus shelling. Shrapnel and unexploded bombs, however, remain.

Warm Arctic waters and cold continental land are combining to stretch the dreaded polar vortex in a way that will send much of the United States a devastating dose of winter weather later this week with swaths of painful subzero temperatures, heavy snow and powerline-toppling ice.

Meteorologists said the eastern two-thirds of the nation is threatened with a winter storm that could rival the damage of a major hurricane and has some origins in an Arctic that is warming from climate change. They warn that the frigid weather is likely to stick around through the rest of January and into early February, meaning the snow and ice that accumulates will take a long time to melt.

Millions of Americans from New Mexico to the Carolinas are bracing for a potentially catastrophic ice storm that could crush trees and power lines and knock out power for days, while many northern states all the way to New England could see enough snow to make travel nearly impossible, forecasters say.

An estimated 100 million people were under some type of winter weather watch, warning or advisory on Wednesday ahead of the storm, the National Weather Service said.

Landslides hit a house and a campground in New Zealand on Thursday, leaving at least two dead while emergency crews were trying to rescue others buried in rubble, officials said.

The first hit a house in the community of Welcome Bay on New Zealand's North Island at 4:50 a.m., police said. Two people escaped the house, and the bodies of two who were trapped inside were recovered hours later, Emergency Management Minister Mark Mitchell said.

Warming temperatures are forcing Antarctic penguins to breed earlier and that's a big problem for two of the cute tuxedoed species that face extinction by the end of the century, a study said.

With temperatures in the breeding ground increasing 5.4 degrees Fahrenheit (3 degrees Celsius) from 2012 to 2022, three different penguin species are beginning their reproductive process about two weeks earlier than the decade before, according to a study in Tuesday's Journal of Animal Ecology. And that sets up potential food problems for young chicks.

South Africa declared a national disaster Sunday over torrential rains and floods that have killed at least 30 people in the country's north, damaged thousands of homes and washed away roads and bridges.

The declaration was made by the head of the National Disaster Management Center and announced by the government. It allows the national government to coordinate the response to the disaster.

Wildfires raging across central and southern Chile have left at least 18 people dead, scorched thousands of acres of forest and destroyed hundreds of homes, authorities said, as the South American country swelters under a heat wave.

Chilean President Gabriel Boric declared Sunday a state of catastrophe in the country's central Biobio region and the neighboring Ñuble region, around 500 kilometers (300 miles) south of Santiago, the capital.