The Australian fruit fly has a constant companion in its nightmarish existence – the blood-sucking parasite Gamasodes queenslandicus. These mites are as big as a basset hound and stalk their prey while they sleep, attached themselves like ticks. For fruit flies living in Queensland’s fruit orchards and rainforests, this is a reality that can be deadly if not avoided.

Biologists at the University of Cincinnati have studied the benefits and costs of avoiding these parasites in a study published in the Nature journal Biological Timing and Sleep. According to Professor Michal Polak, co-author of the study, the parasite poses a potentially deadly threat to fruit flies. “If they have too many mites, they can get ripped apart. It’s very detrimental to them,” he said.

To understand how fruit flies avoid these parasites, researchers captured wild flies in Queensland and bred 16 generations in their lab, selecting only males that were able to survive a night’s close exposure to the mites unscathed. The results showed that the flies that were adroit at evading the mites’ efforts did so at the expense of losing valuable sleep.

“This is not the first study to observe behavioral adjustments in animals exposed to external parasites,” said UC Professor Joshua Benoit, the study’s lead author. “Researchers have found that parasitism also affects the sleep patterns of bats and birds.”

The researchers examined changes in gene expression relating to the flies’ metabolism in the mite-resistance population. They found that mite-resistant flies were more prone to starvation and leaned more on their nutrient reserves than other flies.

“These hypervigilant flies were more active, slept less and consumed more oxygen at night,” Benoit said. “When we measured it, we found that more than 30 metabolism genes were differently expressed in these flies suggesting they were burning their energy a little faster than you’d expect.”

The study’s findings highlight the importance of sleep in all higher animals. As Benoit noted, “Sleep is usually beneficial to animals infected with internal parasites such as those that cause malaria.” However, when it comes to external parasites like mites, the picture changes.

“It behooves the fly to avoid getting parasitized in the first place,” Polak said. “The mites cause a massive up-regulation or down-regulation of hundreds of genes. These defense mechanisms can be very costly to the fly.”

In conclusion, the study shows that fruit flies sacrifice sleep for survival when facing the threat of parasites. This high cost of avoidance has consequences of its own, affecting the flies’ metabolism and behavior. The findings offer valuable insights into the complex relationships between animals and their parasites, highlighting the importance of understanding these interactions to better protect vulnerable species.

The article’s original findings have been rewritten to improve clarity, structure, and style while maintaining its core ideas. Here’s the rewritten version:

Researchers at the University of Bristol recently conducted a groundbreaking study on medical detection dogs, uncovering statistical links between their performance in scent detection tasks and their emotional states. The study, published in PLOS One, found that “optimistic” dogs tended to perform better overall on detection tasks, while “pessimistic” dogs had higher specificity in scent detection.

To assess the dogs’ emotional states, researchers used a behavioral test called judgment bias testing. In this test, dogs are first trained to associate specific locations with treats and others without treats. When presented with intermediate locations where a treat may or may not be present, the dogs’ responses are evaluated as a proxy for their emotional states.

More “optimistic” dogs, characterized by quicker approaches to intermediate locations in hopes of a treat, tended to score higher on detection tasks. These dogs also showed higher confidence, food orientation, and playfulness scores. In contrast, more “pessimistic” dogs achieved a higher degree of specificity in scent detection tasks among the fully trained medical detection dogs.

This study does not establish cause-effect relationships, but it suggests that differences in dogs’ searching styles and performance in detection tasks could be influenced by underlying differences in affective or cognitive processes. The researchers propose that judgment bias testing might hold promise as a screening tool for potential detection dogs.

The findings have significant implications for training and selection methods in medical detection dogs. Understanding the link between emotional states and performance can help trainers select and support successful dogs. The study’s insights could also be relevant to the welfare of companion dogs, highlighting the importance of considering their emotional well-being in their care and management.

Super-Herds of Prehistoric Rhinos Revealed

A groundbreaking study by researchers at the University of Cincinnati has shed new light on the social structure of a prehistoric species of rhino that roamed North America 12 million years ago. The research, published in the journal Scientific Reports, reveals that these ancient creatures lived in vast herds, often numbering over 100 individuals, and exhibited surprising stability in their habitats.

The study’s lead author, Clark Ward, used isotopic analysis to track the movements of Miocene rhinos across landscapes. By examining ratios of strontium, oxygen, and carbon in fossil teeth, researchers were able to reconstruct the animals’ feeding habits, climate, and habitat preferences with remarkable precision.

“We found that they didn’t move very much,” Ward said. “We didn’t find evidence for seasonal migration or any response to the disaster of the volcanic eruption.”

The research focused on Teleoceras major, a one-horned rhino with a barrel-shaped body and stubby legs similar to hippos. Like hippos, these ancient rhinos fed on grass and spent much time in and around water. Their calves would have been vulnerable to predators like bone-crushing dogs, which had left their tracks at the Nebraska site where many specimens were found.

The researchers also found that ash from Yellowstone’s supervolcano eruption would have covered everything, including grass, leaves, and water, causing the rhinos to starve to death over a prolonged period. This finding contradicts previous assumptions that the animals might have converged on the same area seeking shelter from the disaster.

“This is an important contribution to our understanding of the social structure of ancient species,” said John Payne, an expert on endangered Sumatran rhinos in Malaysia. “I’m not surprised that these analyses suggest that Teleoceras major lived in herds, given their resemblance to modern hippos.”

The study’s lead author, Clark Ward, has a personal connection to the site where many of the fossils were found. As an intern at Ashfall Fossil Beds State Historical Park, he had participated in fossil excavations and preparation, answering visitors’ questions about the fossils. He expressed his honor and privilege in having his name attached to the site, which held special significance for him as a childhood favorite.

The discovery of these ancient super-herds has significant implications for our understanding of prehistoric species and their social structures. It highlights the importance of continued research into the lives of ancient creatures and their habitats, providing valuable insights into the natural world and our place within it.