Understanding the animal kingdom
This month, we are focussing on the weird and wonderful animal kingdom, from the secrets of snake teeth and wild boar-butterfly relationships, to bee populations and the feeding habitats of minke whales. Explore more scientific insights into the animal kingdom by visiting the Ecology and Evolution Research Community.
Snake teeth secrets revealed
Love them or loathe them, snakes have an interesting evolutionary history, with their long, limbless bodies and highly modified skulls setting them apart from their lizard relatives. However, as researchers study the fossil record of snakes, the anatomical differences between snake and lizard relatives becomes increasingly blurred over geological timescales. How can palaeontologists distinguish the two animals apart in fossils from millions of years ago? Aaron LeBlanc and colleagues suggest that tooth replacement could act as an anatomical biomarker to confirm the identity of a fossil. Like most reptiles, snakes constantly replace their teeth, but the difference lies in how they shed old ones. The team looked at histology (bone) sections under the microscope, finding that cells fill the pulp of each tooth, slowly eating away at the tooth from the inside. Over time, the tooth base becomes weak enough for the tooth to break away and allow a new one to erupt from the jaw in its place. There is no evidence of this process occurring in lizards and other reptiles, but it can be seen in CT scans of fossil snake jaws, suggesting this method can be used by palaeontologists to identify snake fossils, even from jaw fragments. Read more about this research here.
Pesticide risk for bees
Pesticides are needed for crop production, but they can be extremely harmful for non-pest species, including bees. As an important pollinator species, declining bee populations are very concerning for the wider ecosystem. Jessica Knapp and colleagues wanted to better understand how bees are exposed to pesticides in agricultural settings and how bee species alters pesticide risk so that action can be taken to stabilise bee numbers. The researchers used trap nests and sampled bee colonies in different crop settings (apple, oilseed rape and red clover), discovering that species with long foraging ranges, such as honeybees, were universally harmed by pesticides, irrespective of the agricultural location. However, short range foragers (including the solitary bee and bumblebees) had a slightly lower pesticide risk. To bridge the pesticide risk gap between different species, the authors suggest that semi-natural habitats (such as wildflower corridors) should be created around agricultural fields to help buffer pesticide exposure for wild bee populations. Read more about this research here.
Wild boars could rescue endangered butterflies
Global biodiversity is threatened by habitat loss and environmental degradation. Across Europe, the number of butterfly species has declined as specialist habitats have been lost and fewer plants are now available to butterflies to lay their eggs on. Rocco Labadessa and a team of researchers investigated whether ecosystem engineers, such as wild boar, could help endangered butterfly populations by creating microhabitats as they forage. The team surveyed grassland habitats in Southern Italy, looking for occurrences of the Italian festoon, a protected butterfly species that only lays eggs on a few herbaceous plant species. They found that the specific plants used by the butterflies were more abundant in areas experiencing wild boar rooting of the soil and were surrounded by plants that could provide ample nectar for the Italian festoon. Therefore, the wild boar appears to be a key ally for this endangered butterfly species. Discover more about the study here.
Antarctic minke whales eat a lot
Minke whales commonly eat krill through engulfment filter feeding, opening their mouths wide to obtain as large a catch as possible and filtering out the water with fringes of baleen. The same feeding strategy is employed by their significantly larger relative, the blue whale. But how does animal size affect foraging efficiency? David Cade reports that minke whales accelerate three to four metres per second when they lunge for prey and filter their catch quickly compared to blue whales (which can take up to a minute to separate all the seawater from their foraged krill). To understand why this difference occurs, the team tagged almost thirty minke whales in Antarctica and found that these whales had higher foraging rates than other baleen whales. This allowed the team to understand more about why whales have to be so big – the answer lies in there being a maximum feeding rate allowed for whales of any given size, which is limited by how quickly a whale can catch and filter its prey. Developing knowledge of this feeding behaviour can help scientists to better identify the risks that wildlife faces in our rapidly changing oceans. Learn more about these marine mammals here.
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About the author
Charlotte Bird is the Research Communities Content Manager at Springer Nature and is responsible for showcasing the multidisciplinary research published in our journals through commissioning Behind the Paper posts and engaging audiences via the Nature Portfolio Instagram and Twitter accounts.
