You may have missed… colourful hummingbirds, Jupiter’s faint rings, and Australia’s falling birth rate

Hummingbirds – the most colourful birds of all

A new study has discovered that in a hotly contested field, hummingbirds are the most colour-diverse of all bird species.

And they’re not just ahead – ornithologists found that the range of colours visible to birds in hummingbird plumages exceeds the diversity of colours in all other bird species combined.

“We knew that hummingbirds were colourful, but we never imagined that they would rival all the rest of the birds combined,” says Richard Prum, professor of Ornithology, of Ecology, and Evolutionary Biology at Yale University in the US.

The team collected data on the wavelengths of light reflected by feathers of 1,600 samples of plumages from 114 species of hummingbirds. They compared this information with an existing dataset of colours found in the plumage of 111 other bird species. The samples of hummingbirds increased the total of known bird-visible plumage colours by 56%.

Birds have four types of colour cones in their eyes that are sensitive to red, green, blue, and ultraviolet/violet colours. They see all the same colours as humans but can also perceive more, including ultraviolet, and mixtures of ultraviolet with other hues, like ultraviolet-yellow and ultraviolet-green.

The research has been published in Communications Biology.

Cancer cells and drug-delivering nanoparticles

Using nanoparticles to deliver drugs to tumours offers a way to hit cancer cells with large doses of chemotherapy drugs while avoiding harmful side effects. But so far only a handful of nanoparticle-based cancer drugs have been approved for use by the US Food and Drug Administration (FDA).

Now, a new study published in Science may help overcome some of the obstacles in the development of nanoparticle-based drugs.

Researchers analysed the interactions between 35 different types of nanoparticles and nearly 500 types of cancer cells to reveal thousands of biological traits that influence whether those cells take up different types of nanoparticles. 

The findings could help researchers better tailor their drug-delivery particles to specific types of cancer, or might allow them to design new particles that take advantage of the biological features of particular types of cancer cells.

“We are excited by our findings because it is really just the beginning — we can use this approach to map out what types of nanoparticles are best to target certain cell types, from cancer to immune cells and other kinds of healthy and diseased organ cells,” says senior author Paula Hammond, professor of Engineering and head of the Department of Chemical Engineering a Massachusetts Institute of technology, US.

A silk alternative to some microplastics

Microplastics are tiny pieces of plastic that have become ubiquitous worldwide – polluting the air, water, soil, and have even been found in the bloodstream of animals and people.

Some of these microplastics are intentionally added to a variety of products, including agricultural chemicals, paints, cosmetics, and detergents, to protect specific active ingredient(s) from being degraded until they are needed.

Now, the search is on for biodegradable replacements, and a team of scientists have developed a new system based on silk that could provide an inexpensive and easily manufactured substitute.

The researchers used a widely available silk protein to make a water-soluble herbicide product, in a process described in a paper in the journal Small.

Australia’s birth rate lowest in more than a decade

The rate of women giving birth in Australia has gradually fallen from 66 per 1,000 in 2007 to 56 per 1,000 in 2020, according to the latest report from the Australian Institute of Health and Welfare (AIHW).

This is the 30th annual report on mothers and babies from the National Perinatal Data Collection (NPDC). The data is based on births reported by midwives and other birth attendants in each state and territory in Australia.

Looking at reported births in 2020 indicates that the average age of mothers has continued to increase over time, with mothers now giving birth at an average age of 30.9 years (up from 30.0 years in 2010). There has been a decline in the proportion of teenage mothers from 3.8% in 2010 to 1.8% in 2020, and a higher proportion of mothers aged 40 and over giving birth (4.5% in 2020 compared with 4.1% in 2010).

The report also captures data from the first months of the COVID-19 pandemic in Australia and shows that the number of babies born declined by around 7,100 (2.3%) between 2019 and 2020.

“More than 9 in 10 of the almost 296,000 babies born in Australia during 2020 were born at term and at a healthy birthweight,” says AIHW spokesperson Deanna Eldridge.

Why Jupiter doesn’t have rings like Saturn

Behemoth of the solar system, the gas giant Jupiter ought to have larger, more spectacular rings than Saturn does. But new research has shown that Jupiter’s massive moons prevent the planet from forming substantial rings that could viewed easily with traditional stargazing instruments.

Researchers ran a dynamic computer simulation accounting for the orbits of Jupiter’s four main moons, the orbit of the planet itself, and information about the time it takes for rings to form.

“We found that the Galilean moons of Jupiter – one of which is the largest moon in our Solar System – would very quickly destroy any large rings that might form,” says lead researcher Stephen Kane, an astrophysicist at the University of California – Riverside, in the US.

If moons are massive enough, their gravity can either push ring-forming ice out of a planet’s orbit or change the orbit of the ice enough so that it collides with the moons.

The simulation suggests that it’s unlikely that Jupiter had large rings at any point in its past.

The results are now online, soon to be published in the Planetary Science Journal.