Latest news with #JournalofAnimalEcology
Yahoo
21-04-2025
- Science
- Yahoo
Scientists baffled after observing unusual behavior in vulnerable bird species: 'Their farming actions play an important role'
The superb lyrebird, an Australian ground-dwelling songbird, has long been known for its talent for mimicry and elaborate mating dance. But scientists recently discovered that this bird is more than a master impressionist with a knack for shaking its tail feather — it's also a forest farmer with a surprisingly big impact. As reported by researchers at La Trobe University recently published findings in the Journal of Animal Ecology that reveal the lyrebird actively cultivates its own food supply by raking through the forest floor. With this behavior, it plays a key role in maintaining biodiversity, offsetting what it eats by continuously replenishing the food source — and even preventing forest fires. By observing the lyrebird's natural foraging technique and recreating it in a simulation, researchers learned just how much the bird was altering the environment and helping its favorite foods — invertebrates like worms, spiders, and centipedes — thrive. According to the study's lead author, Alex Maisey, "Lyrebirds set up the perfect home for their prey, creating conditions with more food resources and effectively fattening them up before eating them." In an article for The Conversation, the authors added: "The interaction between lyrebirds and invertebrates has wide benefits for forests. Invertebrates help cycle nutrients and disperse seeds. They also provide food for many birds, small mammals and reptiles." Not only are lyrebirds enriching habitats for other creatures by spreading nutrients, but they're also helping prevent bushfires — a natural part of Australia's ecosystem that has become more frequent and intense due to rising global temperatures. The researchers found lyrebirds can move around a whopping 155 tonnes (171 tons) of organic material per hectare, making sure it breaks down and enriches the soil. "Lyrebirds are widespread and active across millions of hectares of forest. Their farming actions play an important role in maintaining forest biodiversity," said Dr. Maisey. By recognizing lyrebirds as "ecosystem engineers," conservationists hope to better protect their habitat — and in turn, protect the forests they help maintain. These findings show just how vital local biodiversity is — and how much we rely on native species to maintain balance in the natural world. If you're feeling inspired by this feathered forest farmer, you can take local action to support native wildlife and sustainable ecosystems in your own community. Do you think America does a good job of protecting its natural beauty? Definitely Only in some areas No way I'm not sure Click your choice to see results and speak your mind. As Dr. Maisey told the British Ecological Society: "Without the lyrebird, these forests would be vastly different — poorer in biodiversity and less resilient to disturbances like fire. Understanding and protecting these natural ecosystem engineers is crucial for maintaining the health of our forests for future generations." Join our free newsletter for good news and useful tips, and don't miss this cool list of easy ways to help yourself while helping the planet.
Yahoo
18-04-2025
- Science
- Yahoo
Sea slugs harness the power of the sun to show off their colors
Sea slugs don't shy away from the fish, crabs, sea turtles, or even other sea slugs that might want to take a bite out of them. Instead, the brightest and most patterned sea slugs are more active during the day. The sun's rays are critical in enhancing the slug's ability to ward off predators with its flamboyant appearance. The findings are detailed in a study published April 15 in the Journal of Animal Ecology. A team from the University of Queensland in Australia analyzed sea slug coloration across 45 eastern Australian species. Poisonous animals like some nudibranchs–aka sea slugs–and poisonous dart frogs have evolved very vivid hues. 'Sea slugs use bright, contrasting colour patterns to send messages to potential predators like 'Don't eat me, I'm poisonous,'' study co-author and visual ecologist Cedric van den Berg said in a statement. The team used special cameras and software to simulate what the sea slugs would look like to a potential predator. They focused on finding any shared properties in color patterns among sea slug species, which directly correlate with daytime activity. The researchers then used sophisticated statistical methods to combine close to 160 different varieties of color patterns into one single fingerprint. This fingerprint captured the difference in appearance of species more active during the day or night. They found that sea slugs use bold visual signals like brightly colored spots, thick stripes, or enhanced body outlines to advertise that they are equipped with stinging cells, chemicals, or other defenses. And daylight is linked to making those signals stronger. 'These tactics are strongly linked to being active during daytime when there's enough light for these signals to function,' van den Berg said. 'It makes sense for these species to avoid the risky and potentially costly experience of being nibbled on or even ingested by a predator whether they are toxic or not. Their bold appearance also educates predators by being distinct from other animals while also increasing the chances of being remembered.' According to the team, the more nocturnal sea slug species don't need to evolve bright colors and patterns aimed at signaling to potential predators. Nocturnal sea slug predators are less likely to use their vision to hunt overnight, when the senses of touch and smell are more important. The team hopes that this new research will lead to more work on understanding how defensive coloration evolved in marine species.
Forbes
17-04-2025
- Science
- Forbes
When Sharks Return, Reefs Respond
The return of sharks to Ashmore Reef after marine protection was enforced in 2008 shows how top ... More predators influence not just what they eat, but how other species behave. New research reveals that sharks reshape reef communities by triggering fear-based responses in mid-sized fish, which affects feeding, reproduction and even population sizes. In the turquoise waters off the north-west coast of Western Australia, Ashmore Reef has become a living laboratory for understanding what happens when big predators come back. Once depleted, shark populations around this remote reef have been rebounding since 2008, when the area was granted fully enforced 'no-take' Marine Protected Area status. And with the return of these top predators, the newly published study gives us a glimpse into how predators do more than eat their prey — they change the very way ecosystems work. A study published in the Journal of Animal Ecology led by Dr. Mark Meekan and Dr. Emily Lester from The University of Western Australia's Oceans Institute, alongside Dr. Zoe Storm from the University of Glasgow and researchers at the Australian Institute of Marine Science, compared fish communities before and after shark numbers recovered. 'Reef shark populations on Ashmore Reef have increased significantly since effective enforcement of the no-take Marine Protected Area status of the reef started in 2008,' said Dr Mark Meekan. 'This has enabled us to examine how these large predators have the potential to structure reef communities through the behavioural effects they have on their prey.' Using baited remote underwater video systems, the team analyzed footage from 2004 (when shark numbers were low) and from 2016 (when sharks had bounced back). The goal was to track how rising predator numbers influenced the reef's residents. What they found was a clear shift. Alongside the increase in sharks came a rise in other large and mid-sized reef predators. And not only had the number of large and mid-sized predators gone up, but many smaller predatory fish had declined. It wasn't just a case of sharks eating those smaller species. The fish that remained were acting differently too. Fish that previously roamed more freely were now sticking closer to shelter. Some became more cautious, spending less time feeding or mating and more time simply trying not to get eaten — or even seen! — by the returning sharks. 'Our results show how reefs should function in a relatively pristine state,' said Dr Meekan. ... More 'Understanding the role big predators play is essential for building the resilience and survival of coral reef ecosystems, especially as these environments face increasing pressures from climate change, pollution and overfishing.' According to Lester, this shift in behavior is an example of how predators can affect ecosystems even without making a kill: 'Fearful prey react to an increase in predation risk by exhibiting traits to reduce exposure. They may hide more, become warier and forage in lower quality areas. This limits how much energy they can get from food and can reduce reproduction too.' In other words, the mere threat of a predator can change how prey live, a phenomenon known as non-consumptive effects. Storm added that these indirect effects are just as important as actual predation when it comes to shaping ecosystems. 'Predators structure ecosystems not just by what they eat, but by influencing how their prey behave,' she explained. 'This can affect population sizes and community makeup in big ways.' That means sharks, as top predators, play a vital role in keeping reef ecosystems balanced — even when they're not actively hunting. This dynamic, where predators influence prey behavior and that behavior in turn shapes the entire ecosystem, helps explain why top predators like sharks are so important. Understanding how these effects work is key for conservation and reef management. Coral reefs are among the most complex and fragile ecosystems on Earth, and they face numerous threats, ranging from overfishing to climate change. This study, says Meekan, shows what a relatively healthy reef looks like when top predators are back in the mix and highlights how important those predators are for maintaining the balance of the ecosystem. 'Our work contributes to the growing evidence that predators can have important indirect effects on other species in food chains,' Storm concludes, 'by triggering behaviours in prey that attempt to lower their risk of predation.' Ashmore Reef offers a real-world example of what happens when sharks are allowed to return and reclaim their role at the top of the food chain. Their presence is about more than predation — it's about presence itself. The silent power of fear, it turns out, is just as important as the bite. And it's a reminder to all that protecting predators doesn't just save one species… it helps safeguard the entire web of life beneath the waves.
Yahoo
26-03-2025
- Science
- Yahoo
Elephants avoid wasting energy during their epic journeys
For African elephants, currently the largest land animals walking the Earth, finding food efficiently is critical to survival. These endangered pachyderms must eat upwards of 330 pounds of low-calorie vegetation per day to sustain themselves. Yet how they find the best ways to get their greens remains elusive. Data from more than 150 elephants found that they plan their journeys based on both resources availability and energy costs. The findings are detailed in a study published March 26 in the Journal of Animal Ecology and show how every step matters for these gentle giants. 'These new results have important implications for assessing and planning conservation and restoration measures, such as dispersal corridors, by explicitly accounting for the energy costs of moving,' Emilio Berti, a study co-author and ecologist from the German Centre for Integrative Biodiversity Research (iDiv) and Friedrich-Schiller-University Jena said in a statement. The International Union for Conservation of Nature (IUCN) lists the African forest elephant (Loxodonta cyclotis) as Critically Endangered and the African savanna elephant (Loxodonta africana) as Endangered. Increased human activity has further fragmented their habitats, so understanding how they move throughout their landscape is crucial for designing better conservation strategies. They can travel between 31 and 121 miles in a single day, yet the key drivers behind elephant movements across this often harsh terrain have been less clear. In this new study, scientists from the University of Oxford in the United Kingdom, iDiv, and Friedrich Schiller University Jena in Germany used GPS tracking data from 157 African elephants in northern Kenya. The data was collected by conservation organization Save the Elephants from 1998 to 2020. The data indicated that the elephants strongly prefer landscape with lower movement costs. About 94 percent of the elephants in the study avoided rough terrain and steep slopes. According to the team, this suggests that the animals are aware of their surroundings and are making cost-benefit decisions regarding the most energy-efficient paths to take. The elephants also actively select areas that have higher vegetation productivity. Ninety-three percent indicated a preference for going towards more resource-rich environments. Similarly, water sources play a key role in where they choose to go. However, individual elephants can respond to water differently. Some will stay nearby, while others roam further away. This indicates that their movement choices are much more complex than simply traveling over to the nearest body of water. As far as speed, elephants moving at a slow speed show an even stronger avoidance of the difficult, more energetically-costly terrain. About 74 percent of the individual elephants avoided these rough or steep areas when moving slowly. This number jumped to 87 percent when they moved at intermediate speeds and 93 percent when moving fast. The elephants appear to be carefully balancing both effort and energy efficiency on long journeys. According to the team, this behavior is comparable to birds that appear to deliberately use favorable thermal uplifts to reduce the energetic costs of flying. In order to analyze the tracking data, the team used a modelling method called ENERSCAPE. The program estimates the energy costs of movement based on the animals' body mass and the slope of the terrain. By integrating these estimates with satellite data on the vegetation productivity and water availability in the area, the team built detailed energy landscapes that can help better explain elephants' decisions regarding where to move. A statistical approach called step-selection functions was also used to assess how these particular elephants selected which paths to take. This technique compares the locations that the elephants actually visited with other nearby areas they could have selected, but ultimately, did not. By doing so, the team pinpointed which environmental factors likely play a role in elephants' movement decisions and habitat selection. [ Related: African elephants use name-like calls to address each other. ] These new findings could help conservationists design protected areas and migration corridors to reduce conflict with humans. Additionally, the team suggests that conservation strategies should account for these individual differences in habitat preferences, particularly regarding water access. Understanding these results could also help predict how elephant movements may respond to climate change. Increased temperatures and changes to rain patterns affects both the energy costs of moving, and the availability of food and water. In future studies, the team aims to refine energy landscape models by adding seasonal changes, human disturbances, and the impact of climate change on elephant movements into their models. 'While more detailed research is needed to fully understand how an elephant uses its habitat, this study identifies a central decision-making factor for travelling elephants,' study co-author and University of Oxford evolutionary biologist Fritz Vollrath said in a statement. 'Save energy whenever possible.'
Yahoo
06-02-2025
- Science
- Yahoo
Researchers discover unusual factor influencing bird divorce rate: 'Complex, non-linear relationship'
Kissing in the rain is a well-worn romantic movie trope, but it seems bird couplings can be curtailed if the heavens open up. A study published in the Journal of Animal Ecology — and summarized by Sydney's Macquarie University — has found that pair bonds among Seychelles warblers might be affected by environmental factors, with rainfall noted as one of the main reasons that mates "divorce." The research, conducted by a team of international academics, focused on birds found on Cousin Island in the Seychelles. The findings detailed how shifting global weather conditions are altering reproductive activity and harming conservation efforts. "We analyzed 16 years of data and found a complex, nonlinear relationship between rainfall patterns and divorce rates, with divorce being more likely during years of both low and high rainfall," the university's Frigg Speelman, who was involved in the research, said. "This relationship was notably influenced by an extreme climatic event — the 1997 El Niño-induced rainfall spike." According to Speelman, the study provides evidence that environmental conditions can impact the "stability of socially monogamous species." The Seychelles warbler is endemic to the Seychelles islands, and conservation efforts for the bird have already proved challenging. Increasingly unpredictable weather conditions could further impact the species' survival and reduce breeding activity. "This research not only enhances our understanding of animal behavior in the face of climate variability, but it also provides valuable insights that could inform conservation efforts for species vulnerable to the effects of climate change," Speelman said. Human-caused pollution is dramatically shifting global weather patterns. Heat-trapping gases cause temperatures to rise, and this increases the strength, length, and regularity of extreme weather events and also leads to large fluctuations in rainfall. According to the U.N. Development Programme, climate projections for the Seychelles indicate further irregular rainfall patterns. Do you think America has a plastic waste problem? Definitely Only in some areas Not really I'm not sure Click your choice to see results and speak your mind. "Much of the precipitation is falling in sharp bursts, creating heavy flooding in the wet season, while imposing extended period of drought during the dry season," the organization said. BirdLife International lists the Seychelles warbler as "near threatened," with habitat destruction and the presence of introduced predators among the major risks it faces. The warblers can now add rising divorce rates because of unusual rainfall to the list of complications impacting their future survival. While monitoring and research of the species continues, there are things we can do to make a difference in the warblers' prospects, such as reducing the production of pollution that exacerbates fluctuating temperatures. No matter where you are in the world, taking steps to be more sustainable can be felt all over the globe. Whether it's investing in renewable energy or ditching your gas-guzzling car, these changes can have a profound impact on our planet — and help the Seychelles warbler thrive. Join our free newsletter for good news and useful tips, and don't miss this cool list of easy ways to help yourself while helping the planet.
