Great tits eating oak processionary caterpillars


This June 2018 video is about a great tit eating oak processionary caterpillars at their nest. Paul van Heijningen in the Netherlands made this video.

This 17 June 2018 video is about great tits eating oak processionary caterpillars at their nest. Silvia Hellingman in the Netherlands made this video.

This 2 July 2018 video is about great tits eating pupae of oak processionary moths. Silvia Hellingman made this video in Drenthe province in the Netherlands.

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How moths evade bats


This 5 July 2018 video says about itself:

Watch how battles with bats give moths such flashy tails

Long tails fool bats into striking in the wrong place.

Read more here and here.

From the Acoustical Society of America in the USA:

Moths survive bat predation through acoustic camouflage fur

November 6, 2018

Moths are a mainstay food source for bats, which use echolocation (biological sonar) to hunt their prey. Scientists such as Thomas Neil, from the University of Bristol in the U.K., are studying how moths have evolved passive defenses over millions of years to resist their primary predators.

While some moths have evolved ears that detect the ultrasonic calls of bats, many types of moths remain deaf. In those moths, Neil has found that the insects developed types of “stealth coating” that serve as acoustic camouflage to evade hungry bats.

Neil will describe his work during the Acoustical Society of America’s 176th Meeting, held in conjunction with the Canadian Acoustical Association’s 2018 Acoustics Week, Nov. 5-9 at the Victoria Conference Centre in Victoria, Canada.

In his presentation, Neil will focus on how fur on a moth’s thorax and wing joints provide acoustic stealth by reducing the echoes of these body parts from bat calls.

“Thoracic fur provides substantial acoustic stealth at all ecologically relevant ultrasonic frequencies,” said Neil, a researcher at Bristol University. “The thorax fur of moths acts as a lightweight porous sound absorber, facilitating acoustic camouflage and offering a significant survival advantage against bats.” Removing the fur from the moth’s thorax increased its detection risk by as much as 38 percent.

Neil used acoustic tomography to quantify echo strength in the spatial and frequency domains of two deaf moth species that are subject to bat predation and two butterfly species that are not.

In comparing the effects of removing thorax fur from insects that serve as food for bats to those that don’t, Neil’s research team found that thoracic fur determines acoustic camouflage of moths but not butterflies.

“We found that the fur on moths was both thicker and denser than that of the butterflies, and these parameters seem to be linked with the absorptive performance of their respective furs”, Neil said. “The thorax fur of the moths was able to absorb up to 85 percent of the impinging sound energy. The maximum absorption we found in butterflies was just 20 percent.”

Neil’s research could contribute to the development of biomimetic materials for ultrathin sound absorbers and other noise-control devices.

“Moth fur is thin and lightweight,” said Neil, “and acts as a broadband and multidirectional ultrasound absorber that is on par with the performance of current porous sound-absorbing foams.”

New high flying ´Icarus´ moth discovered


Male (left) and female (right) of the newly described owlet moth species Admetovis icarus. Credit: Lars G. Crabo

From ScienceDaily:

Newly discovered moth named Icarus sports a flame-shaped mark and prefers high elevations

October 9, 2018

A newly-recognized species of owlet moth recently discovered to inhabit high-elevation mountains in western North America was named after the Greek mythological character Icarus. From now on, scientists will be referring to the new insect as Admetovis icarus.

In their paper, Dr Lars Crabo, Washington State University, USA, and Dr Christian Schmidt, Agriculture and Agri-Food Canada, explain that the combination of the distinct flame-shaped mark on the moth’s forewing and its high-elevation habitat were quick to remind them of Icarus, who is said to have died after flying so close to the sun that his wings made of wax and feathers caught fire.

The study is part of the seventh volume of the “Contributions to the systematics of New World macro-moths” series, where all previous volumes have also been published as special issues in ZooKeys.

Found in the town of Nederland, Colorado, the moth was collected at an elevation of 2,896 m above sea level. The species has also been recorded all the way from central Utah and central Colorado to the Selkirk Mountains of southeastern British Columbia, including a record from northeastern Oregon. It can be spotted between June and August at night.

In fact, it turns out that the moth has been collected during surveys in the past on multiple occasions, but has been misidentified with another closely related species: Admetovis oxymorus.

While the flame mark is a characteristic feature in all three species known in the genus (Admetovis), in the newly described species it is darker. When compared, the wings of the Icarus moth are also more mottled.

Despite the biology of the larvae being currently unknown, the scientists believe they are climbing cutworms and feed on woody shrubs, similarly to the species Admetovis oxymorus.

“Finding undiscovered moths is not that unusual, even though scientists have been naming insects since the eighteenth century“, says lead author Dr Lars Crabo.

“The Contributions series, edited by Don Lafontaine and Chris Schmidt, in which this discovery is published, really encourages professional and citizen scientists alike to go through the steps necessary to properly name the species that they have discovered. This series of seven volumes also includes a new check list for the United States and Canada, which has led to a re-kindling of interest in moths during the last decade.”

Peppered moths and evolution, new study


This 1 June 2016 video says about itself:

Insect icon Peppered moth mystery solved: BBC News

From the University of Exeter in England:

Study confirms truth behind ‘Darwin‘s moth’

August 17, 2018

Scientists have revisited — and confirmed — one of the most famous textbook examples of evolution in action.

They showed that differences in the survival of pale and dark forms of the peppered moth (Biston betularia) are explained by how well camouflaged the moths are to birds in clean and polluted woodland.

“Industrial melanism” — the prevalence of darker varieties of animals in polluted areas — and the peppered moth provided a crucial early example supporting Darwin‘s theory of evolution by natural selection, and has been a battleground between evolutionary biologists and creationists for decades.

The common pale form of the moth is camouflaged against lichen growing on tree bark. During the Industrial Revolution — when pollution killed lichen and bark was darkened by soot — a darker-winged form emerged in the UK.

Later, clean air legislation reduced soot levels and allowed lichen to recover — causing a resurgence of pale peppered moths.

The example has been well supported by many studies, but nobody had ever tested how well camouflaged the moths were to the vision of their key predators — birds — and how their camouflage directly influenced survival.

Now scientists at the University of Exeter have shown that, to the vision of birds, pale moths are indeed more camouflaged against lichen-covered trees than dark moths — making pale moths less likely to be eaten by birds in unpolluted woodland and giving them an evolutionary advantage.

“This is one of the most iconic examples of evolution, used in biology textbooks around the world, yet fiercely attacked by creationists seeking to discredit evolution”, said Professor Martin Stevens, of the Centre for Ecology and Conservation on the University of Exeter’s Penryn Campus in Cornwall.

“Remarkably, no previous study has quantified the camouflage of peppered moths, or related this to survival against predators in controlled experiments.

“Using digital image analysis to simulate bird vision and field experiments in British woodland, we compared how easily birds can see pale and darker moths, and ultimately determine their predation risk.

“Our findings confirm the conventional story put forward by early evolutionary biologists — that changes in the frequency of dark and pale peppered moths were driven by changes in pollution and camouflage.”

Most birds can perceive ultraviolet light — invisible to human eyes — and see a greater range of colours than humans, and the Exeter scientists analysed how well pale and dark moths matched lichen-covered and plain tree bark, as seen by birds.

To do this, they used museum specimens including some from the collections of Bernard Kettlewell, who conducted famous research on the evolution of the species in the 1950s.

The researchers also created artificial moths, baited them with food and observed predation rates in UK woodland, mostly in Cornwall.

“Through a bird’s eyes, the pale peppered moths more closely match lichen-covered bark, whereas darker individuals more closely match plain bark”, said first author Olivia Walton, who conducted the research as part of her master’s degree at Exeter.

“Crucially, this translates into a strong survival advantage; the lighter moths are much less likely to be seen by wild birds when on lichen-covered backgrounds, in comparison to dark moths.”

In the experiment using artificial moths, lighter models had a 21% higher chance of “surviving” (not being eaten by birds).

“We provide strong direct evidence that the frequency of the peppered moth forms stems from differences in camouflage and avian predation, providing key support for this iconic example of natural selection,” Professor Stevens said.

The research was funded by the Biotechnology and Biological Sciences Research Council (BBSRC).

The paper, published in the journal Communications Biology, is entitled: “Avian vision models and field experiments determine the survival value of peppered moth camouflage.”

The birds that most commonly eat peppered moths include sparrows, great tits, blue tits, robins and blackbirds.