Thursday, September 3, 2020

Animal behaviour: Leading the young: older male elephants prove they are "up to the tusk!"

Journal: Scientific Reports
Male elephants socialising along the Boteti River. Credit: Connie Allen.

Older male elephants may have important roles to play as experienced leaders to younger males when navigating unknown or risky environments, according to a study published in Scientific Reports. 


In long-lived species, such as elephants and whales, older individuals often respond more appropriately to complex, changing environments, which may benefit younger group members. However, research in this area has tended to focus on females.

Connie Allen and colleagues investigated grouping behaviour and patterns of leadership in 1,264 male African savannah elephants travelling on elephant pathways to and from the Boteti River in the Makgadikgadi Pans National Park (MPNP), Botswana. 
Male African elephants congregate along hotspots of social activity
on the Boteti River. Credit: Connie Allen.
The authors found that lone elephants accounted for 20.8% (263 elephants) of sightings on elephant pathways. Adolescent males travelled alone significantly less often than expected, unlike mature adult males who were more likely to travel alone than expected, which may suggest that lone travel is riskier for younger, newly independent and less experienced individuals. Older adults were significantly more likely to travel at the front of groups of males, suggesting that mature adult bulls act as repositories for ecological knowledge and that they may be important leaders during collective movement in all-male groups of African savannah elephants.

Old males being considered reproductively redundant is commonly used as an argument to support the legal trophy hunting of old males, according to the authors who suggest that such selective harvesting of older males could disrupt the wider bull society and the inter-generational flow of accumulated ecological knowledge.

Mining for renewable energy could worsen threats to biodiversity

Nature Communications
A University of Queensland photo.
Threats to biodiversity could increase in the future as more mines target materials used for renewable energy production, suggests a study in Nature Communications.

Renewable energy production is necessary to mitigate climate change. However, only 17% of current global energy consumption is achieved through renewable energies. Generating the required technologies and infrastructure will lead to an increase in the production of many metals, which may create potential threats for biodiversity.

Laura Sonter and colleagues mapped mining areas globally and assessed their coincidence with biodiversity conservation sites. The authors found that mining potentially influences approximately 50 million km2 of the Earth’s land surface with 82% of mining areas targeting materials used in renewable energy production. When looking at the spatial overlap between mining areas and conservation sites, they found that 8% of mining areas coincided with nationally-designated Protected Areas, 7% with Key Biodiversity Areas and 16% with Remaining Wilderness (sites considered important priorities for halting diversity loss).

The authors discovered that a greater proportion of pre-operational mines are targeting materials needed for renewable energy production (nearly 84%) compared to around 73% of operational mines. They also observed that pre-operational mines targeting renewable materials also appear to be more densely packed together than those targeting other materials.

Increasing the extent and density of mining areas will cause additional threats to biodiversity suggest the authors, and they argue that without strategic planning these new threats to biodiversity may surpass those averted by climate change mitigation.

Sunday, August 30, 2020

New research finds - global heating is melting vast northern fields of permafrost so fast that - within decades - they'll likely stop cooling the planet as they have for millennia - and start doing just the opposite.

by Larry Powell
Permafrost Slide at Big Fox Lake, Ontario, Canada - 2015.
A Creative Commons photo by MIKOFOX. 


For thousands of years, so-called "permafrost peatlands" in Earth's Northern Hemisphere have been cooling the global climate. They’ve done it by trapping large amounts of carbon and nitrogen which would otherwise escape into the air as harmful greenhouse gases. 

More recently however, scientists have observed, they've been melting due to manmade global heating. As they melt, they're releasing large amounts of substances like methane - a potent greenhouse gas - into the air. 

But, without proper maps, it's been hard for scientists to get a handle on the degree to which this might be happening - until now. New ones drawn up using thousands of field observations, show; Permafrost peatlands cover a vast area of almost four million square kilometres.

And, to quote from the study, "Under future global warming scenarios, half to nearly all of peatland permafrost could be lost this century.” 

This means their age-old role, mostly as net “sinks,” keeping harmful greenhouse gases in the ground, would transform to a net source of atmospheric carbon, primarily methane.

A permafrost "slump" in Alaska. A USGS photo.

The research concludes that, “Although northern peatlands are currently a source of global cooling, permafrost thaw attributable to anthropogenic climate warming may convert peatlands into a net source of warming."

The findings were published recently in PNAS, the proceedings of the National Academy of Sciences (US). 

But the impact of the nitrogen trapped in these fields cannot be underestimated, either. A separate study, also published in PNAS about three years ago, reveals, "Some 67 billion tons of it, accumulated thousands of years ago, could now become available for decomposition, leading to the release of nitrous oxide (N2O) to the atmosphere. N2O is a strong greenhouse gas, almost 300 times more powerful than CO2 for warming the climate. Although carbon dynamics in the Arctic are well studied, the fact that Arctic soils store enormous amounts of nitrogen has received little attention so far. We report that the Arctic may become a substantial source of N2O when the permafrost thaws, and that N2O emissions could occur from surfaces covering almost one-fourth of the entire Arctic."

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Thursday, August 27, 2020

Damage from whopper hurricanes rising for many reasons

PHYS ORG
Hurricane Laura in Lake Charles, Louisiana - Tornado Trackers
          A destructive storm is rising from warm waters. Again. Story here.

Wednesday, August 19, 2020

There is at least 10 times more plastic in the Atlantic than previously thought

Science News 

"Seal trapped in plastic pollution" by tedxgp2 

Scientists measured 12-21 million tons of three of the most common types of plastic in the top 200 meters of the Atlantic. By assuming the concentration of plastic in the whole Atlantic is the same as that measured at 200 meters deep, the scientists estimated there is around 200 million tons of three of the most common types of plastic alone. Compare this to the previously estimated figure of 17 million. 

Details here.

Thursday, August 13, 2020

Why deforestation and extinctions make pandemics more likely

nature
A public domain image.

As humans diminish biodiversity by cutting down forests and building more infrastructure, they’re increasing the risk of disease pandemics such as COVID-19. Many ecologists have long suspected this, but a new study helps to reveal why: while some species are going extinct, those that tend to survive and thrive — rats and bats, for instance — are more likely to host potentially dangerous pathogens that can then jump to humans. Details here.

Monday, August 10, 2020

Agriculture replaces fossil fuels as largest human source of sulfur to the environment

PHYS ORG
A PinP photo.

Historically, coal-fired power plants were the largest source of reactive sulfur, a component of acid rain, to the biosphere. A new study shows that fertilizer and pesticide applications to croplands are now the most important source of sulfur to the environment. Details here.