Elephants are worth 76 times more when they’re alive than dead, according to a new analysis released this past weekend. The report follows on the heels of findings by WWF that the world has lost 50 percent of its wildlife over the past 40 years, with more than half of African elephants killed for ivory in just one decade. The analysis, conducted through the David Sheldrick Wildlife Trust’s iworry campaign, compared the value of elephants to local economies to profits netted through the illegal ivory trade.

A mass of thousands of walruses were spotted hauled up on land in northwest Alaska during NOAA aerial surveys earlier this week. An estimated 35,000 occupied a single beach – a record number illustrating a trend in an unnatural behavior scientists say is due to global warming. Walruses (Odobenus rosmarus)—iconic arctic mammals that are only distantly related to seals—traditionally use sea ice to rest, breed, and give birth, and as a vantage from which to spot mollusks and other food sources. However, as their habitat warms and sea ice melts, walruses are forced to come to land more often and in greater numbers.

Roads make it possible to bring goods to market, to get to the office, to log a forest, to hunt its wildlife. Without roads, human society as we know it could not exist. However, to build roads, trees must be cleared and swamps drained, shrinking valuable wildlife habitat and fragmenting populations in the process. A new study, published today in Nature, unveils an innovative map that defines which areas of the world would best be used to build roads – and which should be left alone. Scientists estimate more than 25 million kilometers of new roads will be built worldwide by 2050, representing a 60 percent increase over 2010 numbers. Many of these are slated for environmentally valuable places with high numbers of unique species and pristine forest, such as the Amazon Basin.

Scientists at Stanford University recently unveiled a new modeling program that can predict the response of the environment to the land-use changes of human communities. Using their model, they found that natural resources can support humanity – up to a certain point. They recently published their findings in the journal Environmental Modelling & Software.

Bottom trawling is a practice used by commercial fisheries around the world in which a large, heavy net is dragged along the ocean floor to scoop up everything in its path. Previous research has linked trawling to significant environmental impacts, such as the harvest of large numbers of non-target species, collectively termed “by catch,” as well as destruction of shallow seabeds. Now, a new study published in Proceedings of the National Academy of Sciences finds this method is also resulting in long-term, far-reaching consequences in the deeper ocean and beyond. Trawling dates back to the 1300s, and it became widespread in coastal areas around the world after the industrialization of commercial fishing in the late-1800s. Bottom trawling targets commercially valuable species that live near the sea floor, such as cod, rockfish, and various kinds of squid and shrimp. Gear varies depending on the fishing outfit, but nets can be nearly as large as a city block and scoop thousands of fish and other marine animals in a single drag.

In a cave in Australia, researchers from the University of New South Wales discovered giant fossilized sperm. The sperm were produced 17 million years ago by a group of tiny, shelled crustaceans called ostracods, making them the oldest fossilized sperm ever found. The results were published recently in Proceedings of the Royal Society B. The fossils were excavated in 1988, but it wasn’t known they contained sperm until they were studied in detail by an ostracod expert last year.

In the waters off the coast of northern Australia lives a species of feathery coral. Years ago, bits of it were collected by the Australian Institute of Marine Science and stored at the National Cancer Institute’s extract repository, along with 200,000 other samples. When researchers retrieved and tested it, they found that it was very effective at blocking HIV infection of host cells.

Forestry authorities in China have stopped commercial logging in the nation’s largest forest area, marking an end to more than a half-century of intensive deforestation that removed an estimated 600 million cubic meters (21 billion cubic feet) of timber. The logging shutdown was enacted in large part to protect soil and water quality of greater China, which are significantly affected by forest loss in the mountainous region.

Most people are familiar with coral reefs, but very few have ever heard of their algal equivalent – rhodolith beds. Yet, these structures provide crucial habitat for many marine species. In the first study of its kind, published in mongabay.com’s Tropical Conservation Science, researchers unveil just how important these beds are for bottom-dwelling organisms, and the species that depend on them. Superficially similar to coral, rhodoliths are made up of various kinds of photosynthetic red algae (Corallinaceae and Rhodophyta species) that form hard structures as they grow. They drift along with the currents, gradually accumulating calcium carbonate in their cells, until they get too heavy for water to move them.

It holds the Guinness World Record for having the most names of any animal on the planet, with 40 in English alone. It’s also the widest-ranging native land animal in the Americas, yet is declining throughout much of its range. Mongabay talks with big cat expert Dr. Howard Quigley about the status and research implications of the elusive, enigmatic, and unique cougar.