New research using stable isotopes sheds light on how New Zealand’s diverse range of toothed whales and dolphins coexist

Hexbyte Glen Cove

Locations for 21 species of cetaceans (denoted by shape and color) sampled in New Zealand between 2010 and 2021. Sample size for each species is denoted in parentheses. Bathymetry is depicted with darker shades of blue representing deeper waters. Credit: National Institute of Water and Atmospheric Research (NIWA) under a CC BY license, with permission from NIWA original copyright [33]

An international collaborative study involving researchers from Massey University, the University of Canterbury, NIWA, and Flinders University has analyzed the isotopic niche of 21 species of toothed whales in New Zealand.

Results show that some species have a clear niche separation, while others overlap substantially.

The study, published this week in the international journal Biology, details almost no overlap in niche space between sperm whales and Gray’s beaked whales, which are both species foraging in deep waters. However, for species foraging in coastal waters or the open ocean, may be fierce, with species in these habitats overlapping substantially with each other in their foraging niche.

Research lead Dr. Katharina Peters of the University of Canterbury says, “Animals often go to great length to avoid competition and enable coexistence. When there is a large overlap in foraging niche, it is possible that they avoid competition in other ways, for example, foraging during different times of the day.”

New Zealand is home to an extraordinarily rich marine fauna, including 50% of the world’s whale and dolphin species. This rich abundance almost guarantees that some species are competing for their dinner. Study co-author Professor Karen Stockin, who leads the Cetacean Ecology Research Group at Massey University, says, “We have been studying these animals for more than 20 years but still there is so much we don’t understand about their feeding ecology. Stable isotopes collected from stranded animals [have] now offered us first insights to the trophic levels at which these complex mammals feed and compete.”

% %item_read_more_button%% Hexbyte Glen Cove Educational Blog Repost With Backlinks — #metaverse #vr #ar #wordpress

Hexbyte Glen Cove Curiosity rover captures shining clouds on Mars thumbnail

Hexbyte Glen Cove Curiosity rover captures shining clouds on Mars

Hexbyte Glen Cove

Curiosity Spots Iridescent (Mother of Pearl) Clouds. Credit:  NASA/JPL-Caltech/MSSS

Cloudy days are rare in the thin, dry atmosphere of Mars. Clouds are typically found at the planet’s equator in the coldest time of year, when Mars is the farthest from the Sun in its oval-shaped orbit. But one full Martian year ago—two Earth years—scientists noticed clouds forming over NASA’s Curiosity rover earlier than expected.

This year, they were ready to start documenting these “early” from the moment they first appeared in late January. What resulted are images of wispy puffs filled with that scattered light from the setting Sun, some of them shimmering with color. More than just spectacular displays, such images help scientists understand how clouds form on Mars and why these recent ones are different.

In fact, Curiosity’s team has already made one new discovery: The early-arrival clouds are actually at higher altitudes than is typical. Most Martian clouds hover no more than about 37 miles (60 kilometers) in the sky and are composed of water ice. But the clouds Curiosity has imaged are at a , where it’s very cold, indicating that they are likely made of frozen carbon dioxide, or dry ice. Scientists look for subtle clues to establish a cloud’s altitude, and it will take more analysis to say for sure which of Curiosity’s recent images show water-ice clouds and which show dry-ice ones.

Curiosity Shows Drifting Clouds Over Mount Sharp. Credit:  NASA/JPL-Caltech/MSSS

The fine, rippling structures of these clouds are easier to see with images from Curiosity’s black-and-white navigation cameras. But it’s the color images from the rover’s Mast Camera, or Mastcam, that really shine—literally. Viewed just after sunset, their ice crystals catch the fading light, causing them to appear to glow against the darkening sky. These twilight clouds, also known as “noctilucent” (Latin for “night shining”) clouds, grow brighter as they fill with crystals, then darken after the Sun’s position in the sky drops below their altitude. This is just one useful clue scientists use to determine how high they are.

Curiosity Navigation Cameras Spot Twilight Clouds on Sol 3072. Credit:  NASA/JPL-Caltech

Even more stunning are iridescent, or “mother of pearl” clouds. “If you see a cloud with a shimmery pastel set of colors in it, that’s because the cloud particles are all nearly identical in size,” said Mark Lemmon, an atmospheric scientist with the Space Science Institute in Boulder, Colorado. “That’s usually happening just after the clouds have formed and have all grown at the same rate.”

These clouds are among the more colorful things on the Red Planet, he added. If you were skygazing next to Curiosity, you could see the colors with the , although they’d be faint.

“I always marvel at the colors that show up: reds and greens and blues and purples,” Lemmon said. “It’s really cool to see something shining with lots of color on Mars.”

Curiosity rover captures shining clouds on Mars (2021, May 28)
retrieved 29 May 2021

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

Read More Hexbyte Glen Cove Educational Blog Repost With Backlinks —