from the world's big
Scientists are befuddled by where the shark gets most of its food.
- A University of Sydney research team found that the great white shark spends an unexpectedly large amount of time feeding close to the sea bed.
- The group examined the contents in the stomachs of 40 juvenile white sharks and found the remains of a variety of fish species that typically inhabit the sea floor or are buried in the sand.
- The scientists hope that the information gained from this research will assist conservation and management efforts for the species.
Fresh findings<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzM5MjMyNC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYwNjY5NDExM30.3JLqvvn4iB0F29jWuRMnEdmSwY6avTsmo6AP3LgXMxQ/img.jpg?width=1245&coordinates=0%2C333%2C0%2C334&height=700" id="362cb" class="rm-shortcode" data-rm-shortcode-id="f21b84cc3825bf4ac53454c6c4bbb09f" data-rm-shortcode-name="rebelmouse-image" />black shark in blue waterPhoto by Gerald Schömbs on Unsplash<p>A research team from the University of Sydney looked at sharks off the east coast of Australia and found that in their stomachs were remains from a variety of fish species that typically inhabit the sea floor or are buried in the sand. Specifically, the group examined the contents in the stomachs of 40 juvenile white sharks, scientifically known as <em>Carcharodon carcharias</em>, who were caught in the NSW Shark Meshing Program. </p><p>"This indicates the sharks must spend a good portion of their time foraging just above the seabed," explained lead author Richard Grainger, a Ph.D. candidate at the Charles Perkins Centre and School of Life and Environmental Sciences at the University of Sydney, <a href="https://phys.org/news/2020-06-great-white-shark-diet-scientists.html" target="_blank">in a press release</a>. "The stereotype of a shark's dorsal fin above the surface as it hunts is probably not a very accurate picture." </p><p>The study was published on June 8, World Oceans Day, in the journal Frontiers in Marine Science<em>. </em>It's an important step forward for scientists trying to better understand the great white's diet and migratory behavior. </p><p>"We discovered that although mid-water fish, especially eastern Australian salmon, were the predominant prey for juvenile white sharks in NSW, stomach contents highlighted that these sharks also feed at or near the seabed," <a href="https://phys.org/news/2020-06-great-white-shark-diet-scientists.html" target="_blank">said Vic Peddemors</a>, Ph.D., a co-author from the NSW Department of Primary Industries (Fisheries). </p><p>The research team compared this new dietary information with published data on great white feeding habits from other parts of the world where the sharks make home, mostly South Africa. From there they were able to establish a nutritional framework for the species. </p>
What's in a great white's diet?<p><a href="https://www.frontiersin.org/files/Articles/532445/fmars-07-00422-HTML/image_m/fmars-07-00422-t001.jpg" target="_blank">According to the research</a>, the juvenile great white sharks' diets relied primarily on pelagic — mid-water ocean swimming — fish, such as Australian salmon. This made up 32.2 percent of the shark's diet. Bottom-dwelling fish like stargazers, sole or flathead made up 17.4 percent; batoid fish such as stingrays 14.9 percent; and reef fish, like eastern blue gropers, 5 percent.</p><p>The remaining species eaten by the sharks were unidentified fish or less abundant prey. Grainger pointed out that other marine mammals, sharks, and cephalopods — squid and cuttlefish — were eaten at lower rates. </p><p>"The hunting of bigger prey, including other sharks and marine mammals such as dolphins, is not likely to happen until the sharks reach about 2.2 meters in length," <a href="https://phys.org/news/2020-06-great-white-shark-diet-scientists.html" target="_blank">Grainger said</a>.</p><p>Another discovery was that bigger sharks tended to have diets that were higher in fat. Similarly to other animals, this is likely an adaptation to their higher energy needs for migration. Great white's migrate seasonally along Australia's east coast, traveling from southern Queensland to northern Tasmania. The range of distance covered increases with age. </p><p>"This fits with a lot of other research we've done showing that wild animals, including predators, select diets precisely balanced to meet their nutrient needs," said co-author Professor David Raubenheimer, Chair of Nutritional Ecology in the School of Life and Environmental Sciences.</p>
Species conservation and management<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="7bb54774f7a5b923690ad15c2e979aca"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/O2FInaOCqoo?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>Ultimately, the scientists hope that the information gained from this research will assist conservation and management efforts for the sharks, who are considered a vulnerable and declining species due to overfishing and accidental catching in gill nets.</p>Of particular interest to scientists is better management of relations between humans and great whites. According to <a href="https://www.nationalgeographic.com/animals/fish/g/great-white-shark/" target="_blank">National Geographic</a>, of the over 100 annual shark attacks that happen worldwide, a whopping one-third to half can be attributed to great whites. Yet, research has found that the sharks, who tend to have a curious disposition, are often just taking sample nibble before releasing their human prey. So, at least we know humans aren't a great white delicacy.
Maybe you've been wondering if you're seeing one persistent squirrel or a rotating cast of characters.
Watching the wildlife outside your window can boost your mental well-being, and it's something lots of people have been doing a lot more of lately.
Carbon nanotubes embedded in leaves detect chemical signals that are produced when a plant is damaged.
Researchers decoded the love signals of lizards "spoken" through chemical signals.
- Scientists discovered that lizards developed novel chemical communication signals when relocated to tiny island groups with no predators.
- Male lizards began to rapidly produce a new chemical love elixir, not unlike cologne, to call on potential mates.
- With new technology we're increasingly able to detect and identify the chemicals that make up much of the language of non-human nature.
Discovery of lizard love language dialects<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzE2OTMzOC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1MjA1MjcxMH0.WZUBceriGkgHhb5yza4468TF9aJDvmdJGqW7wVERHgU/img.jpg?width=1245&coordinates=0%2C89%2C0%2C90&height=700" id="0bda9" class="rm-shortcode" data-rm-shortcode-id="9c6e02aa7dfbb5e8f23aed152fd1e21b" data-rm-shortcode-name="rebelmouse-image" />
Agios Artemios was one of the islets that a lizard group was relocated to.
Photo Credit: Colin Donihue<p>Researchers from Washington University in St. Louis relocated 12 female and eight male Aegean wall lizards from a single source lizard population in Greece to five tiny islands with no predators. Under these happy conditions, the lizard population proliferated and competed aggressively—evidenced by bite scars—for resources. Researchers tagged each individual lizard so that they could be identified and checked up on over the course of four years.</p><p>As the scientists made visits back to the lizard populations to note how they and their offspring were doing, they made a exciting discovery. On each of the islands, the male lizards had made new chemical cocktails different from the chemical secretions of the lizards in the original source population. The changes had happened rapidly, becoming evident to the scientists after just four generations.</p><p>Could this be evidence that male lizards spruce themselves up with new, au naturale "cologne" when in new ecological settings? The researchers think so, pointing out that having no predators around likely made all the difference. </p><p>"Signals to attract mates are often conspicuous to predators," said Simon Baeckens, a postdoctoral fellow at the University of Antwerp in Belgium and co-author of the new paper, in a <a href="https://source.wustl.edu/2020/04/lizards-develop-new-love-language/" target="_blank">university news release</a>. "As such, sexual signals present a compromise between attractiveness and avoidance of detection. However, on these islets, there is no constraint on the evolution of highly conspicuous and attractive signals." </p><p>In other words, with no snakes or other predators to clue in on their prey's potent chemical secretions, the male lizards could let loose on their love signals without worry. </p><p>"In the experimental islands, we found that the 'signal richness' of the lizard secretions is the highest—meaning that the number of different compounds that we could detect in the secretion is the highest," <a href="https://source.wustl.edu/2020/04/lizards-develop-new-love-language/" target="_blank">Baeckens added</a>. </p><p>Though the researchers are still working to decode the signals, they note that previous research suggests that this more elaborate signal may advertise high "male quality" and possibly immune function to both lure females and tell other males to scram. </p><p>"Lizards deposit their chemical messages encoded in secretions from specialized glands located on their inner thighs," reported Talia Ogliore for <a href="https://source.wustl.edu/2020/04/lizards-develop-new-love-language/" target="_blank">Washington University</a>. "The secretions are a waxy cocktail of lipid compounds that contains detailed information about the individual lizard that produced them."</p><p>Lizards are able to collect those chemical messages from their environment by rapidly flickering out their slim, nimble tongues. They process those cues via a sensory organ in the roof of their mouths.</p>
Chemical dialects<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="71eb9f69f0ff048c645911b7b444da85"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/7kHZ0a_6TxY?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>Most chemical signals between animals fall out of the parameter of human perception, and are therefore more complex to examine. So when studying animal communicative signals, studies have typically prioritized sound and sight.<br></p><p>But chemical "language" is the oldest and most widely used communication mode in nonhuman nature. Life spanning from bacteria to <a href="https://www.the-scientist.com/features/plant-talk-38209" target="_blank">plants</a> to <a href="https://link.springer.com/chapter/10.1007/978-1-4615-4733-4_23" target="_blank">beavers</a> all communicate through this medium. So research like this new paper on lizard love signals represents a valuable opportunity for deciphering ways that animals communicate and perceive the world around them. </p><p>"What we've discovered is that within species there is important variation in chemical signals depending on your context: Who's trying to eat you, who wants to mate with you and who you're trying to compete with," said <a href="https://biology.wustl.edu/people/colin-donihue?" target="_blank">Colin Donihue</a>, a postdoctoral fellow in biology in Arts & Sciences at Washington University in St. Louis and lead author of the new study.</p><p>Donihue also pointed out that nonhuman species have spent more than a billion years developing complex chemical languages. Only relatively recently have humans been able to decipher those methods of communication. </p><p>"With new technology though we're increasingly able to detect and identify these chemical compounds and this is leading to exciting new possibilities for understanding how species interact and evolve," Donihue told Big Think. "As these chemical assays become more common, cheaper, and easier to conduct, I think we're going to find that there are chemical communicators in the plant and animal world that are every bit as exotic and impressive as the bright feathers or intricate birdsongs that are currently the subject of so much research."</p><p>This is likely just the beginning for gaining understanding as to what nonhuman beings, like lizards, are saying to one another right under our noses. </p>This research was published on April 21 in the <a href="https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2656.13205" target="_blank">Journal of Animal Ecology</a>.
These pink feathered folk form complex social networks and are choosy about who they spend their time with, according to a new study.
- A five-year study conducted by researchers at the University of Exeter shows that flamingos are choosy about who they spend their time with.
- Flamingo friendships are made and maintained long-term due to preference rather than loose, randomly made connections.
- In 2009, Madison, Wisconsin, named the plastic pink flamingo the city's official bird.
Research findings<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzA4ODQ4NC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyOTg0Mjk0OH0.0kHti5uD5VAzFV2c5Pz4HJNPJWyIp0L-Y3C8bQK9kyQ/img.jpg?width=1245&coordinates=0%2C0%2C0%2C0&height=700" id="9fc5f" class="rm-shortcode" data-rm-shortcode-id="2b64c67c722641d733a2d570c85216b8" data-rm-shortcode-name="rebelmouse-image" />
Photo Credit: Shutterstock<p>The study, published in <a href="https://trello-attachments.s3.amazonaws.com/5abbd0de21543606f77671cb/5e973b531af0401c662673d6/f95d4964cfd0be6e9beb756118bbd829/Flamingo_Study.pdf" target="_blank"><em>Behavioural Processes</em></a>, examined four captive flamingo species held at WWT Slimbridge Wetland Centre in the U.K. from 2013 to 2016 and compared the findings to data collected on the flamingos in 2012. Researchers examined flocks of Caribbean, Chilean, Andean, and Lesser flamingos. Behavioral data was collected by photographic records of the birds, which were taken four times per day in the spring and summer and three times per day in the fall and winter. </p><p>The researchers found that in every flock, the birds had formed social bonds including mating pairs, same-sex pals and groups of three to four close friends. The preferred acquaintances that were noted in 2012 were still present in 2016. </p><p>"We compared birds that were consistently seen together, in close proximity, over time," said Paul Rose, Ph.D., an author of the study, in an email to Big Think. "We repeated our measurements to make sure what we were seeing was not by chance and to be able to build up a picture of who would be most often seen near or with another bird." </p><p>According to the research team, the results indicate that flamingo societies are complex, with flamingo friendships made and maintained long-term due to preference rather than loose, randomly made connections. </p><p>"There have been several pieces of published research that show non-human animals form social bonds that are important to their health and well-being and to the social [organization] of their group (i.e. keeping it together)," explained Rose. "What we think is interesting about the flamingo work is that this is a gregarious bird that gathers in very large flocks, yet within these large flocks there is an element of social choice. So the flamingos must be aware of who is around them to choose who they want to be associating with."</p><p>All of the flamingos in the study were more frequently seen socializing rather than being solitary, though some were especially social, fluttering between groups. The observed flocks varied in size from just over 20 to more than 140, and the findings suggest that the flamingos in the largest flocks displayed the highest occurrence of social interactions </p><p>Additionally, the researchers wanted to see what impact foot health had on individual differences in flamingo social behavior. (Captive flamingos are prone to suffer from changes to the plantar surface of the foot.) The foot health scores, as it turned out, did not matter when it came to predicting the friendships in the three of the four studied flamingo flocks. Though, researchers found that the number of connections made between flamingos was significantly influenced by the season.</p>