Hurricanes lead to more aggressive spiders, study says - WRAL.com - Canadanewsmedia
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Hurricanes lead to more aggressive spiders, study says – WRAL.com

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— In regions of the United States and Mexico that are prone to hurricanes, aggressive spiders are evolving to survive and ride out the storm.

When hurricanes rage along the Gulf of Mexico or charge up the East Coast, they can reshape an entire habitat in a short time. The winds destroy trees and spread debris for miles, putting new pressure on the creatures living in these environments.

But how do creatures adapt when their habitats are so disturbed? Researchers looked at Anelosimus studiosus spiders that live in storm-prone areas along the coast to see how they changed. Their study was published Monday in the journal Nature Ecology and Evolution.

These weather systems are called “black swan events”: a surprising event with a major impact that is explained with the benefit of hindsight. They don’t offer much lead time, so the researchers had to scramble to study the spider colonies before and after projected storms.

The team monitored Subtropical Storm Alberto and Hurricanes Florence and Michael during the 2018 hurricane season. They tried to anticipate the systems’ trajectories and study areas that included 240 female spider colonies, comparing them with areas where spider colonies were unaffected by such storms.

The researchers returned to the sites hit by the storms 48 hours later. About 75% of the colonies survived the initial storm strikes.

“It is tremendously important to understand the environmental impacts of these ‘black swan’ weather events on evolution and natural selection,” said Jonathan Pruitt, lead study author, evolutionary biologist and Canada 150 Chair in McMaster University’s Department of Psychology, Neuroscience & Behaviour. “As sea levels rise, the incidence of tropical storms will only increase. Now more than ever we need to contend with what the ecological and evolutionary impacts of these storms will be for non-human animals.”

The A. studiosis spider species has two main personality traits that are inherited: docile and aggressive.

Aggressiveness can be determined based on their speed, attackers pursuing prey, cannibalizing male spiders as well as eggs and their vulnerability to the invasion of predatory spiders.

On the one hand, aggressive colonies are better at gathering resources in times of scarcity. But when deprived of food or subjected to overheating, aggressive colonies can also suffer from infighting.

“Tropical cyclones likely impact both of these stressors by altering the numbers of flying prey and increasing sun exposure from a more open canopy layer,” Pruitt said. “Aggressiveness is passed down through generations in these colonies, from parent to daughter, and is a major factor in their survival and ability to reproduce.”

The researchers determined that after a storm passed, the colonies that aggressively pursued food and resources were able to produce more egg cases. The spiderlings also had a better chance of surviving into early winter.

In areas that weren’t hit by storms, docile colonies thrived.

These findings were consistent even as the storms varied in duration, intensity and size. The researchers believe this shows that extreme events can shape animal behaviors. They would like to conduct more long-term studies to learn whether this is the case.

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Elon Musk’s Starlink Satellites Are Already Causing a Headache for Astronomers – Gizmodo

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Several Starlink satellites in orbit, as seen above the Cerro Tololo Observatory in Chile on November 18.
Image: Clara Martínez-Vázquez, Cliff Johnson, CTIO/AURA/NSF

Astronomers at a Chilean observatory were rudely interrupted earlier this week when a SpaceX satellite train consisting of 60 Starlink satellites drifted overhead, in what scientists are apparently going to have to accept as the new normal.

Launched into orbit on November 11, the Starlink smallsat train took five minutes to pass over the Cerro Tololo Inter-American Observatory in Chile, according to a tweet from astronomer Clarae Martínez-Vázquez.

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“Wow!! I am in shock!!,” tweeted Martínez-Vázquez. “The huge amount of Starlink satellites crossed our skies tonight at [Cerro Tololo]. Our DECam [Dark Energy Camera] exposure was heavily affected by 19 of them!,” to which she added: “Rather depressing… This is not cool!”

Responding to this tweet, astronomer Cliff Johnson, a team member and a CIERA Postdoc Fellow in Astronomy at Northwestern, tweeted out a view of the disrupted data, showing an array of satellite trails strewn across an image of space.

The astronomers were collecting data using the DECam instrument, a high-performance, wide-field imager on the CTIO Blanco 4-meter telescope, as part of the DELVE survey, which is currently mapping the outer fringes of the Large and Small Magellanic Clouds as well as a significant fraction of the southern sky at optical wavelengths. Key goals of the project are to study the stellar halo around the Magellanic Clouds and detect new dwarf galaxies in orbit around the Clouds or the nearby Milky Way.

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The Starlink-tarnished DECam frame, showing satellite trails across the field of view.
Image: Clara Martínez-Vázquez, Cliff Johnson, CTIO/AURA/NSF

But this research was punctuated as the Starlink train passed overhead during the early morning of Monday, November 18.

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“In this case, 1 out of about 40 exposures we took during our half-night of observations was affected by the satellite trails,” Johnson told Gizmodo in an email. “And in the case of that single exposure, a maximum of 15 percent of the image was affected by the trails. Beyond the image itself, we also had to be careful as the trail-affected image also impacted our survey operations due to the large number of image artifacts biasing our quality-control measurements.”

Taken as a whole, however, “these numbers tend to show that the effect on our science was more on the annoyance level rather than total disruption,” he wrote. That said, “this may only be the beginning of problems for astronomers, so I believe the community reaction and alarm is warranted.” Should the proposed sizes of these satellite megaconstellations—which are projected to include upwards of tens of thousands of individual elements—actually be achieved, “that has the potential to significantly impact our observational data,” said Johnson.

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A similar thing happened earlier this year after the first batch of 60 Starlink satellites was delivered to orbit, with some people even believing they were UFOs. Alarmed by the inaugural batch of Starlink satellites, the U.S. American Astronomical Society issued a warning, saying megaconstellations could threaten scientific observations of space.

The train effect, in which the satellites are lined up neatly in a bright row, is a temporary one. Eventually, the smallsats disperse and enter into their own unique orbits in a process that takes a few weeks. That said, the number of objects in space—dispersed or not—is about to experience a dramatic uptick.

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As it stands, the impacts of these satellite trains “remain manageable” and the “worst effects temporary,” Johnson told Gizmodo.

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“I agree with the tone of the recent IAU statement that calls for immediate, meaningful discussion between regulators, satellite providers, and astronomers to highlight ways that impacts to astronomy can be minimized—and not just optical, but radio astronomy as well—and rule out the worst-case scenarios of unlimited launches and unchecked deployments,” Johnson told Gizmodo.

In response to these concerns, SpaceX has said it is taking steps to color the base of Starlink satellites black, in order to minimize their brightness. Experts aren’t convinced that’ll work, as some observatories use super-sensitive instruments to detect even the faintest objects.

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Scientists will likely have to get used to these sorts of disruptions, as regulating bodies aren’t lending a sympathetic ear. SpaceX has already received approval from the U.S. Federal Communications Commission (FCC) to launch 12,000 Starlink smallsats, and in October, the Elon Musk-led private space firm asked the FCC for permission to launch an additional 30,000 satellites on top of that by the mid 2020s. These satellite trains, along with their associated megaconstellations, will soon become a regular fixture of the night sky—and that doesn’t include constellations that are set to be built by SpaceX’s competitors, including networks proposed by OneWeb, Telsat, and Amazon.

With the starry night already obscured by light pollution from our cities, it seems an unhindered view into space may soon elude astronomers as well.

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Photos Show Evidence of Life on Mars, Claims Scientist – NDTV

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As scientists scramble to determine whether there is life on Mars, a researcher from Ohio University in US believes that there is evidence of insect-like creatures on the red planet.

Courtesy photographs from various Mars rovers, Professor Emeritus William Romoser’s research found numerous examples of insect-like forms, structured similarly to bees, as well as reptile-like forms, both as fossils and living creatures.

“There has been and still is life on Mars,” Romoser said, noting that the images appear to show both fossilised and living creatures.

“There is apparent diversity among the Martian insect-like fauna which display many features similar to Terran insects that are interpreted as advanced groups – for example, the presence of wings, wing flexion, agile gliding/flight, and variously structured leg elements,” Romoser added.

Romoser said that while the Martian rovers, particularly the Curiosity Rover, have been looking for indicators of organic activity, there are a number of photos which clearly depict the insect- and reptile-like forms.

Photo Credit: Ohio University

Numerous photos show images where arthropod body segments, along with legs, antennae and wings, can be picked out from the surrounding area, and one even appears to show one of the insects in a steep dive before pulling up just before hitting the ground.

Individual images were carefully studied while varying photographic parameters such as brightness, contrast, saturation, inversion, and so on. No content was added, or removed.

Criteria used in Romoser’s research included: Dramatic departure from the surroundings, clarity of form, body symmetry, segmentation of body parts, repeating form, skeletal remains, and observation of forms in close proximity to one another.

Particular postures, evidence of motion, flight, apparent interaction as suggested by relative positions, and shiny eyes were taken to be consistent with the presence of living forms.

“Once a clear image of a given form was identified and described, it was useful in facilitating recognition of other less clear, but none-the-less valid, images of the same basic form,” Romoser said. “

An exoskeleton and jointed appendages are sufficient to establish identification as an arthropod.

Three body regions, a single pair of antennae, and six legs are traditionally sufficient to establish identification as ‘insect’ on Earth.

These characteristics should likewise be valid to identify an organism on Mars as insect-like. On these bases, arthropodan, insect-like forms can be seen in the Mars rover photos.”

These creatures loosely resemble bumble bees or carpenter bees on Earth. Other images show these “bees” appearing to shelter or nest in caves. And others show a fossilized creature that resembles a snake.

“The presence of higher metazoan organisms on Mars implies the presence of nutrient/energy sources and processes, food chains and webs, and water as elements functioning in a viable, if extreme, ecological setting sufficient to sustain life,” Romoser said.

“The evidence of life on Mars presented here provides a strong basis for many additional important biological as well as social and political questions,” he added.

The study was presented at Entomological Society of America national meeting.

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Starlink Satellites Posing Issues For Astronomers – Hackaday

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Spotting satellites from the ground is a popular pastime among amateur astronomers. Typically, the ISS and Iridium satellites have been common sightings, with their orbits and design causing them to appear sufficiently bright in the sky. More recently, SpaceX’s mass launches of Starlink satellites have been drawing attention for the wrong reasons.

A capture from the Cerro Telolo observatory, showing the many Starlink satellite tracks spoiling the exposure.

Starlink is a project run by SpaceX to provide internet via satellite, using a variety of techniques to keep latency down and bandwidth high. There’s talk of inter-satellite laser communications, autonomous obstacle avoidance, and special designs to limit the amount of space junk created. We’ve covered the technology in a comprehensive post earlier this year.

The Starlink craft have long worried astronomers, who rely on a dark and unobstructed view of the sky to carry out their work. There are now large numbers of the satellites in relatively low orbits, and the craft have a high albedo, meaning they reflect a significant amount of the sunlight that hits them. With the craft also launching in a closely-packed train formation, there have already been impacts on research operations.

There is some hope that as the craft move to higher orbits when they enter service, this problem will be reduced. SpaceX are also reportedly considering modifications to the design to reduce albedo, helping to keep the astronomy community onside. Regardless, with plans on the table to launch anywhere from 12,000 to 42,000 satellites, it’s likely this isn’t the last we’ll hear about the issue.

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