Contents tagged with conservation
Created: 4/23/2013 Updated: 8/10/2016
When most people think of insect migration, they quite understandably think of the Monarch butterfly. It comes as a surprise to many that some species of dragonflies also migrate. In this part of the world, many of the larger and more familiar species, like Green Darners and Black Saddlebags, are among the migrants.
Swarm of migrating Green Darner (Anax junius) dragonflies outside of the Nature Museum
Migrating swarms of dragonflies have been observed in places like the shores of Lake Michigan, the Gulf Coast of Texas, and along the east coast of Mexico in places like Veracruz. Migrating swarms are sometimes observed near migrating flocks of raptors, and there is some evidence that they provide a significant nutritional resource for migrating hawks.
A saddlebags dragonfly (Tramea sp.) in Veracruz. This is one of the species that migrates.
In contrast to the Monarch migration, there still isn't much known about the dragonfly migration. Details of the timing and the ultimate destination are still unknown. Are the individuals that head south the same ones that return north?
The Cansaburro Dunes in Veracruz. Researchers are trying to determine how the Gulf Coast of Mexico figures in dragonfly migration.
In an attempt to learn more about dragonfly migration, the US Forest Service's Wings Across the Americas program has assembled a group of dragonfly experts, nongovernmental organizations, academic institutions, and federal agencies and formed the Migratory Dragonfly Partnership (MDP). The partnership includes representatives from Mexico, the United States, and Canada. Members of the partnership, including representatives from the Nature Museum, have traveled to Veracruz to observe migrating dragonflies. The partnership meets annually to discuss how best to learn more about dragonfly migration.
You can find out more about ways to help scientists learn more about dragonfly migration by visiting the Migratory Dragonfly Partnership web site.View Comments
Created: 4/19/2013 Updated: 8/10/2016
Several years ago the Chicago Academy of Sciences became involved in the conservation and restoration of the State endangered Blanding’s Turtle. For those of you who visit the museum regularly, you can’t fail to have noticed our beautiful display tank, which houses two sub-adults and some hatchlings.
The hatchlings are headstarted for two years in a controlled environment, which allows us to protect them from predation at their most vulnerable stage. We then release them out into a suitable habitat equipped with a tiny radio transmitter.
After hopefully surviving their first winter hibernating deep down in the mud we begin to track them as soon as the weather begins to warm up in the spring.
Each transmitter has a unique frequency so we know exactly which turtle we are tracking and as we collect data we are able to develop a picture of survival rates and habitat usage. Blanding’s Turtles live to between 60 and 70 years and do not become reproductively viable until their mid teens so, as an organization we have committed to this study for a long time.
Would you like to become involved in this project? Well you can! We have developed a program called ‘Become a Blanding’s Turtle Tracker.’ For $75 per year or $130 for two years you can donate directly to the cost of the radio transmitters and in exchange get regular Enews updates about the research program as well as a brochure and certificate.
What better way to get involved in a current conservation project without leaving the comfort of your own back yard? To become a Blanding’s Turtle Tracker simply click on this link and sign up today. The Blanding’s Turtles will really appreciate your help.
Created: 2/22/2013 Updated: 8/10/2016
Even though it's been a pretty mild winter, we have had some snow and cold weather. It's been months since I've seen a butterfly outside - yet I'm quite confident that as the weather warms next spring, there will again be butterflies here in northeastern Illinois. So where are the butterflies now? Did they migrate off someplace else? Are they hibernating? As it turns out, the answer varies from species to species.
Some butterflies do spend the winter elsewhere. The most familiar example is the Monarch, which spends the winters in the highlands of Michoacán in Mexico. It's the only local species that makes an annual round-trip migration.
Monarch butterflies in Mexico
About a dozen other species spend the winter in the desert southwest or along the Gulf Coast in the Deep South. These include species such as the Buckeye, Painted Lady, and Little Yellow. They don't seem to have much of an organized southward migration; they simply die off in more northern locales as the weather cools in the fall. Each spring they begin dispersing northward as the weather warms, though it may take several generations to arrive here.
Although it may be hard to believe, especially on a really cold day in the middle of winter, some species of butterflies hibernate and spend the entire winter here. Each species has one particular life stage that hibernates. There are examples of all four species being used. Species such as the Purplish Copper overwinter as eggs. These are laid on twigs or leaves, where they remain for the entire winter. Many species, including Baltimore Checkerspots, hibernate as caterpillars. The caterpillars burrow into the leaf litter at the base of their host plants as fall approaches. Many swallowtail butterflies spend the winter as chrysalises. About a half dozen Illinois species, such as Mourning Cloaks, even overwinter as adults. They spend the winter tucked into crevices in logs, or underneath loose bark on trees. These are the species that can be seen flying on the very first warm days of spring, and occasionally even during warm spells in January or February.
Baltimore Checkerspot caterpillars
How do the hibernating butterflies survive? As cold-blooded animals, their body temperatures drop to that of their surroundings. The secret turns out to be in their chemistry. As the days shorten during the autumn, they begin secreting natural antifreezes into their body fluids. The natural antifreezes are necessary no matter which life stage overwinters. If ice crystals form they rupture cells, which is fatal to eggs, caterpillars, chrysalises and adult butterflies alike. The natural antifreezes are small molecules such as glycerol. Glycerol shares many chemical properties with the antifreeze that is used in car engines. Although the body temperature of a hibernating butterfly may drop to well below zero, the glycerol in its body fluids prevents the formation of ice crystals. The butterfly can therefore survive the very low temperatures, become active again when the weather warms in the spring and complete the life cycle. Next time you are taking a walk in midwinter, consider that there are thousands of butterflies tucked away in warm spots, waiting to fly next summer.
Created: 1/11/2013 Updated: 8/10/2016
Today is the birthday of Aldo Leopold.
If you don’t know who he is, you have at least benefitted from the fruits of his work. Leopold is considered the father of modern wildlife management. Most of the principles conservationists use today to ensure that wildlife and people can share the planet together successfully were promoted, perfected, or even developed by him. He wrote prolifically for both technical audiences and the public, but even his scientific writings are pleasurable to read. One of the few books I encourage everyone to read is “A Sand County Almanac.” In this book Leopold presents complex ideas in simple stories about his time in the outdoors. These experiences were the foundation for Leopold’s “conservation ethic.” This ethic was something he arrived at both intuitively and through meticulous data collection. Many studies have later supported his conclusions and the fact that you can see wild flowers in the spring, baby birds foraging in the summer, and deer rutting in the fall is because conservationists and state wildlife agencies have applied these principles in managing the wildlife near you.
Today it is unseasonably warm so I hope you can celebrate Aldo Leopld’s birthday in style—take a walk in the woods. When it gets a little colder, I hope you’ll curl up with one of his books and take some time to learn about the beautiful interactions of nature in your neighborhood.
Created: 1/8/2013 Updated: 8/10/2016
It is said that plumbers get some of their biggest jobs between Thanksgiving and New Years. I don’t know if this is really true but it make sense because this is the time of year when homes are full of people using every sink, tub, and showerhead in the place.
I used water in more than a dozen homes over the holidays and saw some interesting interactions with water delivery systems. In two homes, only one or two people could shower before the hot water was gone. Then, a kid was scalded when washing his hands. Elsewhere, when filling a pitcher with water, a woman ended up soaked when the water from the tap hit the bottom of the pitcher with such force it splashed back out. Another person, scrubbing a frying pan, almost overflowed the sink before the pan was even a little clean.
There were other adventures (including dish soap in the automatic dishwasher) but these problems all have their roots in the same issue: water flow at the spigot head. High water pressure is great and we all want enough water to come out of the faucet to get the job done but sometimes there can be too much of a good thing and, instead of helping us stay clean and hydrated, we end up with messes.
In each of these cases, the problem could have been solved by simply adding an aerator to the faucet. An aerator is essentially just a piece of fine screen that the water passes though. The effect is to add air to the water as it leaves the faucet while and reducing the amount of water used but without reducing felt water pressure. With an aerator, more people will be able to shower on a tank of water and the temperature of the heater can be turned down to a safer level because less hot water is used in each shower. A pitcher will fill with water quickly but it won’t splash back (and, incidentally, chlorine and some other chemicals will leave the water more quickly making it taste better) and you will have plenty of water to scrub with, without overflowing the sink.
Many older homes were built with faucets that did not have aerators. In other cases, when the aerators became clogged or broken they were simply removed. In most cases, adding or replacing an aerator is simple. Depending on the faucet, you can simply unscrew the end of the faucet and install a screen, or you may have to screw in a whole new end that includes the screen. In showers, you can simply replace the shower head. Aerators are widely available and, especially in the shower, can provide an updated look to the faucet and a more comfortable user experience.
Sometimes good stewardship of natural resources requires sacrifice but, when it comes to your faucet, adding an aerator makes the water easier to use and you’ll be saving money and water.
Created: 12/27/2012 Updated: 8/10/2016
Of all the species that we work with in the butterfly conservation lab, by far the most challenging has been the species that is also the most seriously endangered, the Swamp Metalmark. This species has proven difficult at virtually every stage of the captive breeding process. The populations where we can obtain founder stock are small. The few females that we are able to collect don’t lay many eggs. We feel very lucky to get more than 90 or so out of a single female. Contrasts that to Regal Fritillary females that can each produce upwards of 800 eggs. Hatching, larval growth and survival to pupation are all modest at best. In northern Illinois, the species has but a single generation per year, which means that we are confronted with the challenge of successfully carrying caterpillars over the winter, a process that has proven difficult for many species. Despite these odds, we continue attempting to breed the species in the lab so that we can return the species to the fens of northeastern Illinois where it formerly flew.
Swamp Metalmark Chrysalis
Swamp Metalmark Caterpillars
Swamp Metalmark adult butterfly
This past August we were able to obtain 4 females from southern Indiana. True to form one of the females died after laying only a single egg. All told, we were were able to harvest about 80 metalmark eggs. Only 63 hatched. We began feeding them leaves of swamp thistle, their preferred host plant The goal is to have adult butterflies next spring that we can release onto a fen in northwest Cook County.
Throughout September and early October we experienced the kind of gradual attrition that is typical of our experience with the species. We were faced with a dilemma: should we try moving the larvae to cages where they would spend the winter outdoors? We have never succeeded with this approach. Or should we raise them through to adulthood and try to get an additional generation with perhaps greater numbers. We have only once before succeeded in rearing the species to adulthood, but did not get any offspring. Despite the uncertainty, the latter course of action seemed less perilous, so we retained the caterpillars in the lab and continued to offer them food.
By mid October we were down to 21 caterpillars. There the numbers stabilized as the caterpillars continued to eat and grow. With few additional losses, we obtained 19 pupae. At the time of this writing we have about 10 adults, four of which are females. We have paired them in small cages where we hope that mating will occur. After a few days we will move the females into egg laying cages and hope for the best.
Although this species is proving difficult to work with, I believe that it is well worth the effort. Swamp metalmarks were once part of the great species diversity that was found in the fens of Illinois. It my firm hope that they will one day fly there again.