A team of researchers gathered at the Field Museum, Chicago, and took an entire collection of Horned larks to study. By looking at their wings and the dirt and soot trapped on them, they could find out which was the evolution of pollution since the beginning of the 20^th century.

Birds kept soot particles on their feathers

The collection gathers specimens of all ages, some of them being even 100 years old. They are special, since their feathers usually gather traces of all pollutants present in the atmosphere, offering a better insight on pollution during the era of the big factories than any models scientists could build. Therefore, thanks to the traces of pollutants present on their wings, they measured the levels of soot present in the atmosphere back then.

The discovery occurred in the 1930s when researchers noticed some birds of the same species had darker feathers than others. They quickly established the darker shade came from tiny particles of soot trapped within the feathers. However, the first time when the discovery was used was almost 80 years ago, while two scientists were analyzing museum collections.

The soot on the feathers built a comprehensive pollution model

They quickly realized they could find out more about the environment of the time by looking at how it interacted with the birds. Since the bird collection was truly vast, containing thoroughly dated specimens from different periods, the scientists could map a comprehensive distribution of soot and other pollutants over a broader area.

They noticed the highest levels of pollutants at the beginning of the 20^th century, and a big decline during the Great Depression when the factory activity suffered a massive drop. Then, the pollutant emissions rose again, as World War II started. They matched the observations with well-known historical events and discovered this model is more accurate than anything we had previously designed.

Therefore, they managed to build a better analysis of the soot levels in the atmosphere since 1880 and after World War II, which was published in the journal Proceedings of the National Academy of Sciences.

Image Source: Wikimedia

Last night, we could enjoy the view of October’s full moon, nicknamed the Harvest Moon. All the twelve full moons of the year have their own name, but this one holds a unique symbolism. Since it falls close to the equinox, it is known as a moment of change, marking the transition between seasons and the passage to cold and darkness.

The Harvest Moon is closest to the autumn equinox

It’s not obligatory for the Harvest Moon to fall in October. This name is given to all such events which fall closest to the autumn equinox, which occurs near the end of September. However, this year, October’s full moon was closer to the event than September’s. Traditionally, this month’s moon is known as The Hunter’s Moon, but a change marked this year.

The name dates back several centuries ago, when people didn’t have the technology we had today, and the full moon was of great help for them during harvests. As the autumn equinox approached, days got shorter and shorter, and darkness reigned over the fields. This means farmers had less time to gather their crops.

What’s the history of the Harvest Moon’s name?

However, when the Harvest Moon came, the fields were again showered in light, and they gained time to pick up all their crops right before the harsh weather came. Also, near this astronomical event, the skies grew less dark between sunset and moonrise. Therefore, farmers decided to honor this full moon and thank it for its precious help by giving it a special place in history.

Now, these myths no longer apply, but mystery and symbolism still surround the Harvest Moon. Given its position, it is easier to spot shortly after sunset. Sometimes, people find it bigger or tinted with a shade of orange but, in fact, it’s no different than other full moons. This appearance is given by its position closer to the horizon, but this mysticism revolves around it makes it look more magical.

Image Source: Pixabay 

A new study confirms that at least one species of dinosaurs used to lay eggs that were blue-green colored. In turn, this suggests and also confirms that at least some of these animals had features still common in some of their present-day descendants – birds.

The blue dinosaur eggs were discovered after taking a closer look and testing a fossilized dinosaur nest.

Blue Dinosaur Eggs Prove a Further Tie to Modern Day Bird Species

This new research analyzed the fossils discovered in the nest of late species of oviraptor that lived during the Late Cretaceous. The Heyuannia huangi, which lived in China some 66 million years ago, was a beaked, ostrich-like dinosaur.

All reptile species and most bird ones lay white, uncolored eggs. For a long time, it was assumed that dinosaur did so as well. Fossilized dinosaur eggs are usually brown or black colored. This happens because of the iron, iron oxide, or other such minerals that stain them during the fossilization process.

Still, the Heyuannia huangi eggs had a bluish tint, found only in them. So the study team used mass spectrometry to analyze their fossilized nest. In doing so, they found traces of biliverdin and protoporphyrin.

The former is known to be the reason behind the modern birds’ blue and green eggs. At the same time, the latter is known to produce red and brown speckles and coloring.

The team notes that its discovery and confirmation of blue dinosaur eggs further strengthens their ties to modern birds. It also helped offer new clues as to the behavior of the Heyuannia huangi.

Ostrich, emu, and cassowary and known for laying stunning green and blue-hued eggs. These help them camouflage their open ground nests from predators. Such structures are also known for being watched over by the species’ fathers.

The discovery of the blue dinosaur eggs suggests that this ancient species had a similar nesting structure, possibly even the same guarding fathers system.

“According to the sexual signaling hypothesis, the reconstructed blue-green eggs support the origin of previously hypothesized avian paternal care in oviraptorid dinosaurs,” states the research team in its study paper.

This is available in the open journal PeerJ.

Image Source: FreeGreatPicture