The video in the link shows examples of normal bat hunting and what happens when their calls are jammed. Pretty cool!
Most bats use echolocation to find food by bouncing the sounds they make off of any objects nearby to detect where flying prey may be located. This is a very effective technique for them because they are nocturnal and hunt at night, when they would not be able to see most or any of the flying insects that they eat. Since bats usually roost in groups, though, there could be large numbers of them going to hunt in the same area at the same time. An individual bat needs to look out for its best interests and get enough food to feed itself. Scientists recently recorded siren-like sequences in Mexican free-tailed bat calls that were unusual. They ended up shining a spotlight on bats from a platform and playing the recorded sounds back to them, and found that when the calls were well-timed, they could prevent a bat from catching prey over 85% of the time. This means the unusual siren calls are used by bats to jam the echolocation of other bats in the area so they can't find all the food sources. This is the first time jamming has been found in echolocating animal individuals of the same species.
The video in the link shows examples of normal bat hunting and what happens when their calls are jammed. Pretty cool!
People have been worried about the decline in honeybees over the past few years, and one factor that has not helped their situation has been their sometimes-constant exposure to pesticides. Pesticides are sprayed by gardeners on their flowers, by farmers on their flowering crops, and beekeepers use certain pesticides in beehives to keep harmful mites under control. Pesticides can prevent bees from foraging for nectar as effectively because they will not learn as quickly which scents lead to a sweeter reward. Pesticides used in the beehives could build up in such high concentrations in the waxy honeycomb that they could harm the young bee larvae that are being raised in the comb.
For some background on how exactly bees use honey and nectar, the University of Florida Extension has a nice webpage here. Honeybees feed on nectar from flowers and convert that into honey. Nectar is the main source of carbohydrates for bees, and also provides them with some essential minerals. Honeybees feed on honey throughout the winter in their hive when they cannot collect nectar from flowers. Honeybees also collect pollen from flowers and bring it back to the hive in pollen baskets on their legs (you may have noticed the bright yellow or orange bumps on their back legs where these are located). Bees then store the honey long-term after adding enzymes from their glands to it to prevent bacterial growth. This modified pollen is often called "bee bread." Larval bees and newly emerged adults feed on the bee bread to acquire essential proteins to their development. Colonies require 15-55 kilograms of pollen a year! Different plants have different amounts of nutritional components in their pollen, so not all are nutritionally equivalent to bees.
Scientists were interested in studying the effects of honeybee diet on their resistance to pesticides, so they fed miticides (pesticides commonly used by beekeepers for harmful bee mites) to honeybees, and examined differences in their RNA after 7 days. They found the RNA differed in expression of genes linked to immunity, detoxification, and nutrition. The scientists then tried feeding some bees with a natural pollen diet, and others with artificial diets: soy protein or a no-protein diet. They then exposed the bees to a lethal dose of a common crop pesticide, and found honeybees that were fed the pollen diet had lower mortality and sensitivity to the pesticide.
Since humans have been changing our agricultural practices and increasing urbanization, it is likely that bees are not finding as many pollen sources and could be nutritionally-stressed more of the time now than in the past. This could make them more sensitive to the effects of the pesticides. Christina Grozinger, one of the scientists who worked on this study, said, "If we can figure out which diets and which flowering plants are nutritionally optimal for honey bees, we can help bees help themselves."
All that vanilla and cinnamon that people use in their Thanksgiving and Christmas baking can be detected in treated sewage that is released into local water bodies. Scientists first discovered this in Puget Sound in Washington state, when they found increased levels of vanilla and cinnamon in treated sewage being released into the sound between Nov. 14 and Dec. 9.
" "Even something as fun as baking for the holiday season has an environmental effect," said Rick Keil, an associate professor of chemical oceanography. "When we bake and change the way we eat, it has an impact on what the environment sees. To me it shows the connectedness." "
Scientists don't know if these spices are affecting aquatic life, but they could have some effect because fish use their sense of smell to locate food, and some fish, like salmon, use smell to locate their home stream for spawning. The scientists came up with an estimate that residents of Seattle and surrounding areas ate about 160,000 cookies with vanilla each day, and 80,000 cookies with cinnamon daily during the Thanksgiving weekend.
You may have heard about the increased concentrations of antibiotics and medicines in our waterways from people using them or flushing unused pills down the toilet. It turns out that perfume and caffeine can also be detected in treated sewage. I doubt people will change their consumption of baked goods with spices over the holidays (that would make for a less enjoyable holidays, indeed) but knowing that we can detect so many substances in our water, even after it is treated at treatment plants, should make us a little more thoughtful about what goes down our drains.
A curator at the Smithsonian wrote a piece in a newsletter describing how many botanical institutions in the U.S. and around the world are firing their researchers and curators, changing their focus away from systematics and taxonomy, or closing down altogether. I wrote a blog post a few months ago about the research crisis at world-famous Kew Royal Botanic Gardens in England, but I was shocked to read that there are problems at major U.S. institutions such as the Field Museum in Chicago and the California Academy of Sciences, which each have over two million specimens in their collections that are used for research and reference.
Herbarium specimens consist of dried and pressed plants (or lichens and mosses) that are meticulously identified and labeled with location information for where they were collected. I have used them to help teach the Plant Systematics lab class at Michigan State University, and am making my own collection of pressed plants from my field research this past summer, which greatly helped me in properly identifying the species I saw in the field. Many closely-related species have microscopic details that tell them apart from each other, and you cannot accurately identify them outside while you are in the field. Instead, you need to bring specimens back to the lab to look at the morphology of their seeds, hairs, or length of their floral parts (as a few examples) to tell species apart. Some of the useful web resources and hard copies of flora that I use to learn county presence of certain species assemble information from pressed plant specimens deposited into herbariums. (I like using Calflora for California research and Michigan Flora for my Michigan research). This highlights how important botanical collections can be, even for people who aren't studying taxonomy questions but are doing ecological research, where it can be important to document species richness, abundance and diversity for various plant communities. I am particularly interested in exotic, invasive species, so herbarium specimens can act as records of the first documented presence of an exotic species in an area.
The article also highlights how important botanical collections are for studying climate change and how species distributions are changing over time. Considering that pressing plants was a common activity of botanists in the late 1800s, hebariums do have, in some cases, an adequate number of specimens for certain locations from over 100 years ago that can be used to compare to specimens that have been documented in the same locations now and in the decades in between. Sometimes DNA or RNA can be extracted from herbarium specimens for genetic studies, and evidence of disease that causes discoloration or changes in morphology can provide valuable clues on the spread of disease through natural plant populations.
I do hope that trends will change and the specimen collections of natural history museums and botanical gardens, as well as universities and other institutions, will start to receive more funding to preserve their collections and the necessary curator and research positions that are needed to allow scientists to make important discoveries about our natural world.
*note: the article is not restricted to herbarium specimens of plants, but this is what I chose to focus on as this is my area of expertise. Many zoological collections are also experiencing the same threats as well.
A 19-year-old African-American college student from Chicago has already made some major breakthroughs in colon cancer research and is determined to find a cure. Keven Stonewall started an internship in a university lab while he was still in high school and developed an experiment to test a colon cancer vaccine after seeing his close friend's change in behavior from witnessing his uncle falling ill and dying of the disease. Keven tested the potential colon cancer vaccine in older and younger mice, and injected aggressive colon cancer cells into the mice, and found the young mice's tumors were eliminated while the older mice still developed tumors.
Scientists said Keven's finding was very important, especially because two-thirds of colon cancer patients are elderly, and previous drug research has mostly only separated children from adults but not young adults versus elderly. Keven already won awards from science fairs, including the prestigious Intel International Science and Engineering Fair last year. He is currently a biomedical engineering sophomore at the University of Wisconsin - Madison (he won six scholarships to attend college there). He did an internship at the University of Chicago Comprehensive Cancer Center this summer.
Read more about his inspiring story and research here:
Before I read this news article, I did not know that there was such a thing as the Kashmir musk deer, with thin fangs hanging down on both sides of its mouth. These are, in fact, very rare animals that live in forested slopes of Afghanistan. The males use their fangs to fight other males during the mating season (but not to suck blood!). Scientists had last seen them living in 1948, when on a research expedition, but since then, they have been listed as an endangered species. They were not believed to be extinct, because their scent glands are sold on the black market as a traditional medicine and for perfume for $20,000/pound (more valuable than gold), but illegal poaching had dramatically reduced their numbers.
The Wildlife Conservation Society trains and funds local people in Afghanistan to monitor its wildlife, since nonprofit groups have not been able to send researchers to the area since 2010 due to heightened security concerns. The surveyors sighted at least three musk deer in steep, rocky outcrops surrounded by vegetation, including at least one male and a female with a juvenile. This discovery highlights a critical need to protect this species, as well as other rediscovered animals such as the Persian leopard, in Afghanistan's wildlands.
Click one of the links to see a picture of the musk deer with its fangs!
Scientists found 700-year-old caribou dung frozen in ice cores removed from icy patches on the Selwyn Mountains in Canada. To some people, dung may be the last thing they think of as useful for study, but food that animals eat can have tons of viruses in them, including plant matter eaten by caribou. These viruses can be found in poop after going through the digestive system, and well-preserved DNA and RNA from the viruses can sometimes be sequenced. Caribou like to hang out on ice patches to avoid biting insects and heat during the summer, so when they poop on the ice, and more ice covers the poop for thousands of years, the virus DNA and RNA from plant viruses or insect viruses (spread by insects attracted to the feces when they were fresh) does stay well-preserved. In fact, scientists recently recovered a full plant virus genome from the caribou dung that was unlike any present-day plant viruses that are sequenced. They were able to inoculate a type of tobacco plant with the virus (tobacco is often used for scientific research and is susceptible to many plant viruses), and the virus infected the leaves of the plant! A partial insect RNA genome was also recovered from the dung.
Since these viruses are from plants and insects, people do not need to worry that they are a health threat for us. However, it is interesting to think that with increased Arctic ice melt, viruses will be released into the environment and can still infect some plants and insects that are exposed to them.
I'm an ecologist in Michigan, but I'm interested in lots of other types of science, too. I'll share what I find interesting in this blog.