Weekly round-up: March 14

Long-tailed tits vary between raising chicks alone or in groups

Birds that live in groups and receive help raising their young live longer than those parenting alone, and boast an eight per cent higher annual survival rate than their frazzled counterparts.

A study from Lund and Oxford universities reviewed data for 23 species of bird which vary in rearing habits, including the long-tailed tit, sociable weavers and Seychelles warbler. While a proportion of each species raise their chicks alone, others outsource parenting duties.

Co-author Philip Downing from Lund University said: “A common pattern in group-living species is that parents do not care very much for their own young. Instead, the helpers are responsible for feeding and protecting the young and performing the other tasks that are usually associated with being a parent.”

The results showed that birds which shared the parenting burden lived, on average, one to two years longer.

“This may not sound like a lot, but in human terms it equates to about six and a half glorious years,” said co-author Charlie Cornwallis.

Such hands-off parenting has been witnessed in numerous species, including ants, termites and naked mole rats, but because the behaviour is witnessed in all individuals, it was not possible if relieving the stress of childcare was the secret to their longevity.
Publication Philosophical Transactions of the Royal Society B

Almost 100 per cent of red snapper sampled in the Gulf of Mexico following the Deepwater Horizon oil spill suffered liver damage as a result of the disaster.

The study, which assessed around 600 fish from 72 locations between 2011 and 2017, showed 99 per cent of the fish showed an average of five physical signs of liver damage.

Lead author Dr Erin Pulster said: “The results add to the list of other species we’ve analysed indicating early warning signs of a compromised ecosystem.”

On April 20, 2010, an explosion on the Deepwater Horizon killed 11 men and later caused the entire rig to collapse, leading to the worst single ecological disaster in history as 134 million gallons of oil spilled into the Gulf over the three months it took to cap the well.

Last month a study in Environmental Toxicology and Chemistry showed bottlenose dolphins in the Gulf were showing signs of disrupted immune function arising from oil exposure – including those born after the spill.
Publication Aquatic Toxicology

Horseshoe bats are natural reservoirs of coronaviruses, and the likely origin of Covid-19 (Wikimedia Commons)

The World Health Organisation says it has found no evidence that the Covid-19 virus leaked from a laboratory, instead pointing towards the original theory of China’s wildlife trade.

Four WHO scientists reported they have found links between Wuhan’s live-animal wet market and the areas where bats are known to harbour the virus.

The team will release its initial conclusions next week.

Meanwhile, a study published in PLoS Biology revealed the SARS-CoV-2 virus required very little adaptation following its jump from bats to humans in order to thrive in its new host – and spread rapidly.
Source The Independent
Publication PLoS Biology

Hemiandrus jacinda, a flightless cricket named after the New Zealand prime minister (Danilo Hegg)

A new species of cricket has been named after New Zealand’s prime minister Jacinda Ardern, on account of its Labour party red colour and “long limbs”.

The giant flightless cricket Hemiandrus jacinda is a species of wētā, one of more than 100 endemic to New Zealand, of which 18 ground-dwelling species. Identified in the journal Zootaxa, it was described as “comparatively large, long-limbed, glossy and predominantly orange-red”.

It is not the first time such an honour has been bestowed upon the PM, with a beetle, a lichen, and an ant in Saudi Arabia also named after her.

Speaking to The Guardian, author and professor in evolutionary ecology at Massey University Steven Trewick said the striking species had reflected traits of the prime minister, and expressed surprise that such a large insect had not been formally identified sooner.

“In a time of accelerating environmental change, loss of natural habitat and global precipitous decline of the planet’s biological diversity, the work of species discovery continues,” he said. 

“The wētā of New Zealand are a rich and diverse radiation of species living in all sorts of habitats – yet many remain to be recognised.”

However, he also added that wētā are threatened by introduced predators and habitat loss, and the newly discovered species may already be declining in numbers.
Publication Zootaxa 

Alaska’s ‘Rat Island’ has shown remarkable ecosystem recovery following removal of the invasive predators after which it was named, surprising scientists with the speed of its return to a natural balance.

A number of islands off the state’s Aleutian archipelago were inadvertently populated with rats resulting from shipwrecks and occupation during World War II. Rats are renowned for their ability to adapt and thrive in new environments, making them particularly damaging non-native invasive species.

The new residents preyed on shore bird eggs and chicks, devastating the island population and leading to an increase in the intertidal plant-eaters such as snails and limpets which the birds previously consumed – resulting in their numbers growing and a decrease in the marine kelp such invertebrates feed on.

However, conservation efforts to remove the rats in 2008 has resulted in a full recovery of the island ecosystem in just 11 years.

Lead author professor Carolyn Kurle said: “Sometimes it’s hard to say that a conservation action had any sort of impact, but in this particular case we took a conservation action that was expensive and difficult, and we actually demonstrated that it worked. But we didn’t expect it to be so fast.

“Invasive rats are almost always direct predators of native animals when they become introduced on islands. So when the birds returned it led to an entirely different structure in the marine community on this island. It now has a structure that more closely resembles what we observe on islands that have never had rat invaders.”

The island has since been renamed with its original Aleut moniker Hawadax, meaning “the island over there with two knolls”.
Publication Scientific Reports

Read ‘There’s no ice’: warming seas chill Quebec’s seal tourism

Watch The sea slug that can decapitate itself – then regrow its entire body

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