Tuesday, December 13, 2022

Reliance on moose as prey led to rare coyote attack on human

Study assesses animals’ diet, movement in Canadian park

OHIO STATE UNIVERSITY

COLUMBUS, Ohio – Wildlife researchers have completed a study that may settle the question of why, in October 2009, a group of coyotes launched an unprovoked fatal attack on a young woman who was hiking in a Canadian park.

By analyzing coyote diets and their movement in Cape Breton Highlands National Park, where the attack occurred on a popular trail, the researchers concluded that the coyotes were forced to rely on moose instead of smaller mammals for the bulk of their diet – and as a result of adapting to that unusually large food source, perceived a lone hiker as potential prey.

The findings essentially ruled out the possibility that overexposure to people or attraction to human food could have been a factor in the attack – instead, heavy snowfall, high winds and extreme temperatures created conditions inhospitable to the small mammals that would normally make up most of their diet.

“The lines of evidence suggest that this was a resource-poor area with really extreme environments that forced these very adaptable animals to expand their behavior,” said lead author Stan Gehrt, a wildlife ecologist at The Ohio State University.

“We’re describing these animals expanding their niche to basically rely on moose. And we’re also taking a step forward and saying it’s not just scavenging that they were doing, but they were actually killing moose when they could. It’s hard for them to do that, but because they had very little if anything else to eat, that was their prey,” he said. “And that leads to conflicts with people that you wouldn’t normally see.”

The research is published in the Journal of Applied Ecology.

The death of 19-year-old folk singer Taylor Mitchell is the only fatality resulting from a coyote attack on a human adult ever documented in North America.

Gehrt, who leads the Urban Coyote Research Project that has monitored coyotes living in Chicago since 2000, was consulted by media for his expertise after the attack. In urban areas like Chicago, where thousands of coyotes live among millions of people, injuries from coyote-human encounters are very rare.

“We had been telling communities and cities that the relative risk that coyotes pose is pretty low, and even when you do have a conflict where a person is bitten, it’s pretty minor,” said Gehrt, a professor in Ohio State’s School of Environment and Natural Resources. “The fatality was tragic, and completely off the charts. I was shocked by it – just absolutely shocked.

“A lot of people began wondering if we were at the front edge of a new trend, and if coyotes were changing their behavior. And we didn’t have good answers.”

Gehrt expanded an initial investigation of the fatal attack – and a few dozen less severe human-coyote incidents in the park before and after Mitchell’s death – into a detailed field study. Between 2011 and 2013, he and colleagues captured 23 adult and juvenile coyotes living in the Cape Breton park and fitted them with devices to document their movement and use of space.

To obtain dietary information, the team also snipped whiskers from the live-captured coyotes and from the bodies of coyotes implicated in the fatal attack and in other human-coyote incidents. For comparison, the researchers collected fur from potential prey – southern red-backed voles, shrews, snowshoe hare, white-tailed deer and moose – and hair from local barbershops that served as a proxy for human food.

Seth Newsome, professor of biology at the University of New Mexico and corresponding author of the study, analyzed stable isotopes of carbon and nitrogen in these whisker and hair samples to determine what the coyotes had been eating in the months before they were captured or lethally removed from the population.

The analysis showed that, on average, moose constituted between half and two-thirds of the animals’ diets, followed by snowshoe hare, small mammals and deer.

“This dietary evidence was the critical piece to it,” Gehrt said. “Their diets changed because they’re taking advantage of whatever different food items are available at the time. We’re used to seeing big oscillations across the segments of whiskers depending on the season. But in this system, for these coyotes, we don’t see that – they flat line at the moose end, so there’s very little variation in their diet.”

Samples from the coyotes that were confirmed to have been involved in the fatal attack showed they had been eating only moose, “and their diet wasn’t changing,” he said. An analysis of coyote droppings confirmed the isotope findings. The researchers found only a few examples of individual animals having eaten human food.

Beyond the dietary analysis, Gehrt and colleagues did test for the possibility that coyotes were familiar with humans, and therefore not fearful around people. The movement patterns showed that while the coyotes’ space use was extensive – likely related to the need to search far and wide for prey – the animals largely avoided areas of the park frequented by people and were more active at night during periods when daytime human use was at its highest. Prohibition on hunting and trapping in the park also removed a human threat.

“It’s a big area for these coyotes to live in and never have a negative experience with a human – if they have any experience at all,” Gehrt said. “That also leads to the logical assumption that we’re making, which is that it’s not hard for these animals to test to see whether or not people are a potential prey item.”

In cities and most other wilderness areas where coyotes live, food of all types is plentiful – suggesting only areas low on natural prey, like islands and remote northern climates, would pose a similar risk for coyote-human interactions, Gehrt said. Their survival in Cape Breton, he said, is attributable to their remarkable ability to adjust to their environment.

“These coyotes are doing what coyotes do, which is, when their first or second choice of prey isn’t available, they’re going to explore and experiment, and change their search range,” he said.

“They’re adaptable, and that is the key to their success.”

This work was supported by Parks Canada, the Nova Scotia Department of Lands and Forestry, and the Max McGraw Wildlife Foundation.

Additional co-authors include Erich Muntz of Cape Breton Highlands National Park, Evan Wilson of Ohio State and Jason Power of the Nova Scotia Department of Lands and Forestry.

Contact: Stan Gehrt, Gehrt.1@osu.edu

Written by Emily Caldwell, Caldwell.151@osu.edu

JOURNAL

Journal of Applied Ecology

DOI

10.1111/1365-2664.14333

ARTICLE TITLE

Severe environmental conditions create severe conflicts: A novel ecological pathway to extreme coyote attacks on humans

COP15

Scientists return from expedition after mapping fungal networks on world’s most remote island

As COP15 enters its second week, SPUN’s research team is drawing attention to how underground biodiversity powers the Earth’s ecosystems on land and in the sea

Business Announcement

SPUN (SOCIETY FOR THE PROTECTION OF UNDERGROUND NETWORKS)

Decomposing coconut husk. — IMAGE: TOBY KIERS HOLDS A DECAYING COCONUT HUSK WITH SMALL FUNGI GROWING ON IT. view more
CREDIT: SPUN.EARTH

Palmyra Atoll (December 12, 2022) - In the middle of the Pacific Ocean is an uninhabited atoll that houses underground mycorrhizal networks that may have evolved a unique ability to cycle nutrients between seabirds, rainforest trees, and coral reefs. The Society for the Protection of Underground Networks (SPUN) travelled to this remote atoll – a place so untouched that researchers had to freeze their clothes each night to prevent the introduction of non-native species to the protected islands – for a recent research expedition.

In partnership with The Nature Conservancy Climate Adaptation Lab, SPUN is mapping the diversity of mycorrhizal fungi across Palmyra Atoll, 1,000 miles south of Hawai’i. This atoll, the Earth’s most remote, is the site of much lore, including a double murder, sunken treasure, and disappearing aircrafts. It is also home to a million seabirds, untouched coral reefs, and a fish population that is 44% sharks.

“Never could I have imaged sampling fungi while small sharks swam around my feet. As we hiked in the ocean between forested islands, we could hardly hear ourselves talk because the birds were so loud,” says Dr. Toby Kiers, Executive Director of SPUN. “Visiting Palmyra allows you to go back in time when other organisms – not humans – dominated the landscape.”

The scientists sampling Palmyra hope to understand how mycorrhizal fungi facilitate nutrient movement between the sea and the rainforest – and how remote island ecosystems are coping with climate change, invasive species, and rising sea levels. During the course of the expedition, SPUN scientists collected samples from across 27 islands. These have been sent off for DNA sequencing so that the fungal players can be identified.

Among the island’s species is the towering Pisonia tree. Pisonia is a native rainforest species that has been reported to digest seabirds that get trapped by the sticky substance secreted by its seeds. Kiers and her team conducted extensive sampling of the symbiotic fungi that colonize Pisonia roots to test how nutrients from birds and their guano are captured and fed back to the rainforest trees. Scientists believe that these mycorrhizal fungi create nutrient feedback loops that not only support the island’s rainforests, but also the plankton communities and coral reefs offshore.

“On these remote islands – out of reach of human interference – we see an extreme form of interdependence among organisms on land and sea,” says Kiers. Lose any of these organisms – fungi, crab, birds, tree, corals – and we may witness a devastating cascade effect.

The waters surrounding the atoll host some of the most pristine coral populations in the world. “We know fungi play an important role in mediating the transport and availability of beneficial nutrients to plants. Now, an understanding of similar fungi-coral interactions is emerging,” says Dr. Alex Wegmann, lead scientist for the Nature conservancy’s Palmyra Program. “Palmyra’s intact reef system provides an excellent opportunity to more fully understand the beneficial role of fungi in island and reef ecosystem resilience to climate impacts, like rising ocean temperatures and changing ocean chemistry.”

Palmyra Atoll is also home to the largest crab species in the world. Coconut crabs grow up to a meter wide and are prolific hunters and tree climbers. The science team has hypothesized that these land crabs are helping to distribute the symbiotic fungi to new roots through their digging, re-enforcing the cycling of nutrient among birds, crabs, coral reefs and native rainforest.

Until now, the fungal communities of the atoll had never been studied, and researchers anticipate the discovery of new species able to withstand extreme heat, salinity and low nutrient conditions. Despite being so remote, the islands have been threatened by invasive species. The Nature Conservancy has removed over 1 million non-native coconut palms and eradicated large populations of introduced brown rats. And, as sea levels around the islands rise, erosion is beginning to eat away at Palmyra.

“As the world continues to push past atmospheric carbon thresholds tied to near-future climate impacts, we need to steady for what’s to come,” says Wegmann. “Understanding the role fungi play in the transport and mediation of beneficial nutrients on land and in the ocean will help prioritize conservation actions that promote and safeguard ecosystem resilience.”

Toby Kiers carries supplies to a sampling site on an islet while sampling mycorrhizal fungi on Palmyra Atoll

The native pisonia tree is a key part of the nutrient cycle researchers explored on Palmyra.

A coconut crab scuttles around Palmyra Atoll at night. Scientists believe these crustaceans are part of an important nutrient cycle on the remote islands.

An islet of the Palmyra Atoll, where scientists sampled mycorrhizal fungi to better understand a unique nutrient cycle.

Trees host seabirds on Palmyra Atoll. These seabirds' guano is believed to fuel an important nutrient cycle on the remote islands.

A SPUN researchers surveys the water near a sampling site on Palmyra Atoll.

CREDIT

spun.earth

The expedition was led by Professor Toby Kiers, who was recently named as one of TIME’s emerging leaders of 2022 for her work decoding complex trade interactions among plants and mycorrhizal fungi.

Kiers was joined by Dr. Stuart West (Oxford University, UK) and Dr. Charles Cornwallis (Lund University, Sweden), and remote support was provided by Dr. Alex Wegmann (The Nature Conservancy, USA), Dr. Nicole Hynson (University of Hawaiʻi at Mānoa, USA) and Dr. Kabir Peay (Stanford University, USA)

SPUN (Society for the Protection of Underground Networks) is a science-based initiative to map and protect the mycorrhizal networks that regulate the Earth’s climate and ecosystems. In collaboration with researchers and local communities, SPUN is leading efforts to explore mycorrhizal biodiversity and advocating for the inclusion of fungi in conservation and climate agendas. Visit https://spun.earth/.

The Nature Conservancy is a global non-profit organization dedicated to conserving the lands and waters on which all life depends. Informed by science and guided by traditional values and practices, we apply innovative, nature-based solutions to our world’s toughest challenges so that nature and people can thrive. TNC has forged partnerships to manage 14 preserves and other sites in Hawai‘i and Palmyra Atoll, working with government, private parties and communities to protect Hawai‘i’s and Palmyra’s forests and coral reefs for their ecological value and for the many benefits they provide to people. Visit www.nature.org/HawaiiPalmyra.

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

COP15

Mountain ecosystems should be prioritized in biodiversity policies

Reports and Proceedings

UNIVERSITY OF YORK

More action is urgently needed to safeguard the world’s precious mountain ecosystems, according to a University of York researcher whose policy brief is being presented at this month’s United Nations Biodiversity Conference (“COP15”) in Montreal, Canada.

Professor Robert Marchant is calling on national governments to put mountain environments at the centre of their climate change and biodiversity policy efforts and actions.

The UN General Assembly named 2022 the International Year of Sustainable Mountain Development – some 20 years after the first International Year of Mountains. But while some successes have been achieved in that time, Professor Marchant says national policy simply isn’t keeping pace with land use change, development, population growth and the impacts of climate change on global mountain systems.

“Twenty years on, climates are still changing, populations are still growing, and mountain environments continue to be developed and transformed – but what hasn’t happened is any corresponding establishment of sustainable policies,” he explains.

“Government environmental and business policies are rarely joined up and we are seeing continued widespread land degradation in mountain habitats. This includes uncontrolled grazing, deforestation, or overdevelopment - and much of it is resulting from weak policies and changing tenure laws.”

Mountains cover around a quarter of earth's land mass. They host about half the world’s biodiversity hotspots. They are a hugely important component of global water supply because they receive more rain than lowland areas, experience less evaporation at high elevations, and contain large stores of water as snow and ice.

Well-functioning mountain ecosystems are more resilient to climate extremes – they can buffer shocks such as high intensity rainstorms or prolonged dry spells – and are important stores of carbon and storehouses of biodiversity.

Despite this, mountains don’t receive the corresponding policy attention and investment from their national governments. They are particularly vulnerable to climate change and human interventions, which threaten their globally important ecosystem services.

For example, the area around Mount Kilimanjaro in Kenya is an area of high population density and rapid economic development. It has seen a major expansion in agriculture over the past twenty years, as land has been privatised and companies have realised they can drill deep boreholes in the land to extract water from the mountain’s aquifer.

Professor Marchant notes: “Once you’ve paid for that borehole, that water is a free resource to you. But these services are provided by nature – and no-one is presently paying for either the water resources or for stewardship of that land. Asking companies to pay for this kind of service, by issuing controllable permits for example, would be a step towards treating our mountain resources with more respect.”

Professor Marchant and his co-authors are calling on countries to invest more in mountain ecosystem restoration activities, and to formulate effective climate change policies that consider the unique nature and resources of mountains. Also urgently needed is more international information sharing and data collection on mountain use, as well as better analysis of the current restoration initiatives taking place around the world.

He says: “We are hoping for some progress at COP15, but what is really needed is an international treaty or code of practice that accepts the value of our mountain ecosystems, and I suspect that is some way off.”

‘Ecosystem restoration in the mountains’ is led by the International Centre for Integrated Mountain Development and written by contributors from the University of York, United Nations Environment Programme, Mountain Research Initiative, the Mountain Partnership Secretariat and the Food and Agriculture Organization of the United Nations.

Remains of two new marine worms from 455 million years ago discovered in Morocco

• The finding, which involved the Complutense University of Madrid and the IGEO, identified two well-preserved species of palaeoscolecid worms from the Ordovician: Anguiscolex africanus and Wronascolex superstes

Peer-Reviewed Publication

UNIVERSIDAD COMPLUTENSE DE MADRID

A research project undertaken by the Complutense University of Madrid (UCM) and the Institute of Geoscience (IGEO, CSIC-UCM) identified various marine worms from the Palaeozoic era (Ordovician period) 455 million years ago at the Tafilalt Biota site in Morocco. They correspond to the new genus and species Anguiscolex africanus, and the new species Wronascolex superstes.

Palaeoscolecid worms are not rare in the Paleozoic; the problem is that 99.99% of the fossil record comprises their sclerites (hard plates embedded in the cuticle) in isolation, which typically build up in certain limestone rocks. In other words, this type of worm lived in all the seas of the globe, but there is no evidence of their fossils other than at a tiny fraction of sites.

The worm fossils at the Moroccan site were articulated and well preserved in lutites (fine-grained rocks) and in an environmental context dominated by turbulent waters, which makes the finding, according to the UCM and IGEO palaeontologist Juan Carlos Gutiérrez Marco, a "palaeontological surprise in a far from favourable geological context".

The cuticle of these marine worms, described in Historical Biology, was covered in phosphatic microsclerites (measuring 20-100 thousandths of a millimetre), arranged in rings on the successive segments, their conservation being facilitated by rapid burying, having first been protected beneath bacterial veils which precipitated iron sulphides.

These two individuals are now added to the finding made some years ago, at the same site and by the same research team, of the worm Gamascolex vanroyi.

Worms that lived when Morocco was “polar”

Another of the conclusions highlighted by the study is the "gigantism" of the three worms known in the Tafilalt Biota, which are two to three times larger than the global record of palaeoscolecids in Australia, North America and Central-Western Europe. "This circumstance could be connected with metabolic reasons involved in what is known as "polar gigantism", as Morocco was very close to the Earth's South Pole during the Ordovician Period," Gutiérrez Marco explains.

This is the third of these organisms to be found in the Tafilalt Biota, an outstandingly well-preserved site containing a mixture of fossils from groups with hard parts (trilobites, molluscs, echinoderms) and others with a soft to weakly mineralised body (rare arthropods, worms, paropsonemid discs…).

The finding forms part of the ongoing research into the Ordovician in Morocco in connection with a series of projects under the National Plan (Ministry of Science and Innovation), with 15-day field seasons being organised in the desert terrain a couple of times a year.

The researchers also have a network of collaborators who locate fossils throughout the year, and contact them if they find anything of note.

"We are trying to reconstruct the ecosystems and organisms of the past, and the data obtained help in this case to refine the geological correlation of the fossil-bearing units of Morocco with other contemporaneous units located on the marine shelf of the former continent of Gondwana", the UCM researcher emphasises.

Bibliographical reference: Diego C. García-Bellido & Juan Carlos Gutiérrez-Marco (2022), Polar gigantism and remarkable taxonomic longevity in new palaeoscolecid worms from the Late Ordovician Tafilalt Lagerstätte of Morocco, Historical Biology, DOI: 10.1080/08912963.2022.2131404.