Contents tagged with Chicago Academy of Sciences
Created: 5/3/2013 Updated: 8/10/2016
Stop by North Pond for the next several days to greet our tropical visitors---warblers. There are many species of warblers, small insect eating birds, that live in the tropics during our winter, then fly through our backyards on the way to Canada to spend the summer breeding and eating things like tent caterpillars.
Today the Palm Warbler Setophaga palmarum is common and easy to find. The birds you see today around the pond may have been in Panama or Cuba just a few days ago. Look for the rusty cap and a constantly twitching tail.
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
About three years ago, I began a project of trying to take a bunch of butterfly photos. I had an old lecture with images in 35 mm slide format that I wanted to convert to a digital presentation. In the process, I discovered how much more I enjoyed taking digital photos of butterflies than using the old film format. My project quickly changed from getting images for a talk to starting a virtual butterfly collection.
Buckeye (Junonia coenia),
Willow Springs, IL July 18, 2010
This was one of the first specimens in my virtual collection.
I've collected butterflies most of my life. Early on my collecting was simply a hobby. As I began collecting for a variety of professional purposes, I stopped collecting for fun. Among other things, I couldn't justify taking the butterflies simply for my own amusement. Digital photography has changed all of that.
Caption: California Sister (Adelpha californica)
Madera Canyon, Arizona. July 31, 2012
I've been surprised at how similar digital photography is to collecting specimens. Both involve similar pleasures of the pursuit in the field and both require knowledge of habitats and host plants. Both result in a sense of elation at the moment of capture. Both involve work with the specimen once you get it home. In the case of the physical specimen this work involves relaxing, pinning mounting and labeling. In the case of the photograph, it involves cropping and correcting exposure. For me, one of the enjoyable parts of virtual collecting has been keeping records of date and location of capture that are just as rigorous as those that I would maintain for a pinned specimen.
Olympia Marble (Euchloe olympia).
Illinois Beach State Park May 11, 2011
Ethical and conservation concerns aside, there are additional advantages to virtual butterfly collecting over traditional specimen collecting. Want to collect an endangered species or collect in a National Park? Not so fast- you need a slew of permits and a really good reason to do so. But with a camera, you can take as many images as you would like. Are you traveling abroad and want to collect butterflies? Many countries now prohibit the export of species, and many more require a permit. In contrast, the images on your camera will go right through customs, no problem.
Karner Blue (Lyciades melissa samuelis)
Indiana Dunes National Lakeshore, May 30, 2009
A double whammy: This endangered species was virtually collected in a National Park.
One of the things that I always enjoyed with my specimen collection was looking at my specimens much later and remembering where I was, who I was with, and how much I was enjoying myself. I now get a very similar kind of enjoyment from my virtual collection-- and the specimens in it don't fade or break or get eaten by dermestid beetles. I'll continue collecting actual butterflies for the Nature Museum as the specifics of my work require it. But I also expect to be collecting virtually with my camera for my own enjoyment for the rest of my life.
Fatima Peacock (Anartia Fatima)
Vallarta Botanical Gardens, Jalisco, Mexico, February 15, 2012
I had no trouble getting this virtual specimen of a Fatima Peacock through customs when I returned home from Mexico.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: 4/15/2013 Updated: 8/10/2016
I recently posted this butterfly photo on line:
It's a Ciliate Blue from Malaysia. A friend was prompted to comment, "I like the orange and black "eye" on the edge of the wing. Is it part of a disguise camouflage?"
My friend was very astute in noticing that the spot resembles an eye and surmising that it has something to do with defense against predators. This species is a good example of what is often referred to as the false head hypothesis. The hypothesis notes that the markings on one outer edge of the hind wings resemble heads in some species of butterflies. These markings can be quite elaborate in some cases and may include tails that resemble antennae and a narrow shape that enhances the appearance of a head. Some species carry this even one step further and rub their hind wings together. This draws attention to the tails, which appear like twitching antennae.
Gray Hairstreak (Strymon melinus)
The false head hypothesis suggests the possibility that these head-like markings confer a survival advantage by deflecting predator attacks towards the hind wing (which butterflies can usually live without) and away from the vulnerable head. Many butterflies, especially species in the Metalmark and Gossamer-Winged Butterfly families show these markings.
Martials's Scrub Hairstreak (Strymon martialis)
In 1980, scientists from the Smithsonian attempted to demonstrate that predators could be fooled into attacking the wrong end of the butterfly. They collected hundreds of butterflies in Panama and Colombia, and divided them into groups based on the number of head-like features were present in their wing patterns. Consistent with the false head hypothesis, the greater the number of head-like features, the more likely wing damage due to predator attacks was to be directed to that part of the wings.
Eastern Tailed Blue (Cupido comyntas)
The false head hypothesis remains a hypothesis. Further support of the hypothesis would require a much more difficult experimental design - one that demonstrates that butterflies with the false head designs survive better than those without them.View Comments
Created: 4/15/2013 Updated: 8/10/2016
One Sunday, the PIP volunteers were doing a program called Meet the Bugs. We brought out a praying mantis, darkling beetles, a wolf spider, and a desert millipede to give visitors a close-up look. The inclusion of the spider and millipede meant “Meet the Invertebrates” would be a more accurate description of the program, but Meet the Bugs is catchier and easier to say.
We also brought out superworms, the legged larvae of darkling beetles (superworms is a misnomer), to provide a before-and-after illustration of insect metamorphosis. The superworms would become beetles, we explained, if they were not eaten by one of the Museum’s turtles first.
Several visitors asked how superworms turned into beetles because they look nothing alike. I compared it to caterpillars turning into butterflies. I hope that was helpful to them, but decided I needed to learn more to provide a better-informed answer next time.
So I googled “darkling beetle metamorphosis” when I got home. There were many results illustrating the pupa stage the beetles go through, comparable to the chrysalis stage for butterflies and the cocoon stage for moths. From viewing the scientific drawings, I realized that I had frequently seen mealworm beetle pupa in the oatmeal-filled drawer where the mealworms are kept without recognizing what they were.
I also found several videos on YouTube of the metamorphosis of darkling beetles. The most interesting was an almost 8-minute video that showed in close-up the larva, pupa, and adult stages of the beetle’s life. My favorite part was watching the legs kicking free of the pupa casing as the adult emerged. The video was a 4th grade class project, part of their habitats unit in science. What a great idea. It gave me a much clearer picture of the process that should help me explain it better to others. Check out the video and see for yourself.View Comments
Created: 4/8/2013 Updated: 8/10/2016
While we do not do it every day, the natural history specimens on display the Museum need regular cleaning, particularly those specimens that are not housed inside of museum display cases. Specimens, like the polar bear, accumulate dust just like other surfaces in the museum.
To clean them we use vacuum cleaners with HEPA filters and variable suction control, fine mesh netting, clean brushes, gloves, ladders, extension cords, and time. The netting is placed over the nozzle of the vacuum cleaner so that large particles cannot be accidentally “sucked” into the vacuum.
The suction control is adjusted so that just enough suction is applied to pull in dirt and dust particles from the air, but not to harm the specimens. The brushes are used to gently pull dirt away from the surface of the specimen with the vacuum nozzle head held just above to collect the now loose particles of dust and dirt. This kind of cleaning is performed on a regular schedule for specimens on permanent display or as needed when additional specimens are installed in new exhibits, like the bison mount in Food: The Nature of Eating.
Amber KingView Comments
Assistant Collections Manager
Created: 4/3/2013 Updated: 8/10/2016
We strive to give our Box Turtles a rich and diverse diet, which provides them with good calcium sources to ensure that they develop strong shells. Of course along with strong shells this also means they grow strong nails.
Normally a turtle would be digging and scratching around outside in dirt and rocks and naturally wear their nails down. We do give our turtles lots of time outside in the summer but at this time of the year they are kept indoors and only get to dig in soft substrate. So what to do with those long nails?
That is where the ‘mani, pedi service’ comes in.
We used Claire for these photos, as she is by far the most calm about having her nails trimmed. We use a standard rotating nail file, which is intended for dogs’ nails.
As with most things involving turtles, this is a two-person job. One person to catch and hold the leg and the other person to file the nails.
I did mention that Claire was the most cooperative of our turtles during this process. She accepts what we are doing and just watches reproachfully.
Pretty Girl and Kennicott show what they think of things by peeing as much as possible! Charlie and Opal will try and sneak a quick bite, if a finger should happen to come within reach. And Manny? Well Manny is like a madman! He has to have a board held between his head and our hands, which he attacks viciously. I wonder do the ladies who work in nail salons usually end up bleeding after giving their customers a manicure? At the end of the process, we clean our various scratches and bites and the turtles have nicely manicured nails.
Created: 4/3/2013 Updated: 8/10/2016
I often get calls from people who have discovered a hawk frequenting their bird feeders. They are usually rather upset and want to know what they can do to make it go away. This can often lead to quite an interesting and thought-provoking discussion.
Firstly, why is it OK to provide all other birds with food except hawks? As with all predators, hawks constantly walk a very fine line between survival and starvation. The Coopers Hawk, which is considered one of the most common urban hawks has been extensively studied, and results show that barely 20% of their hunting attempts are successful. Imagine if only once in every five times you decided to have a meal, you actually got one. You would soon be really hungry! The amount of energy required to take to the wing and actively hunt means that every failed attempt is extremely costly to the hawk. Also, studies have shown that the three most common prey species for urban Coopers Hawks are European Starlings, Rock Pigeons and Mourning Doves. Of those, the starling is an invasive species that is rapidly out-competing and threatening less aggressive native species, the Rock Pigeon is widely despised and considered a messy pest by the vast majority of people and the Mourning Dove is one of the most abundant and widespread birds in North America, producing several broods each year.
The problem, of course, comes from the fact that a lot of people do not want to see an animal killed and eaten by another animal. I used to work in Africa as a safari guide and by far and away the most frequently asked for animals were lions and leopards. Big cats will spend up to 23 hours per day lying around resting and sleeping and trust me, that does not make for very interesting game viewing! But when we happened to come upon these same large predators hunting, many people simply could not bear to watch.
To develop a true understanding of our natural world it is important to recognize that predators have a vital part in every ecosystem whether it be a sunfish devouring a minnow, a Peregrine Falcon grabbing a pigeon on the wing or a lion pulling down an antelope, they are all an important part of a healthy and balanced environment.
So next time you are fortunate enough to see a hawk in your yard, try not to be tempted to chase it away. Watch it, observe it’s behaviour in relation to its surroundings, how does it use its environment to approach its prey? Is it successful? If not, why not? Don’t think of the hawk as evil or nasty, instead consider how privileged you are to be witnessing nature right in your own back yard.
Created: 3/18/2013 Updated: 8/10/2016
If you work with museum objects in a natural history museum, “freezing” is a necessary part of the job. It may sound a bit odd to freeze a museum object of any sort, but it enables us to store specimens until they can be prepared and it is also an effective way of killing insect pests without the use of chemical pesticides. The use of pesticides leaves a residue on specimens each time they are used and this causes a build-up over time. By using the freeze-treatment method instead, we reduce this residual build-up and the related side effects that could possibly harm specimens over time and/or become a health hazard to the collections staff that care for them.
Most of the time we can “freeze-treat” our specimens in house, but for larger mounts, like a bison mount that is 6.5 feet tall by 8.5 feet long, we do not own a large enough freezer. Instead we had to seek out a facility that would not only have room to accommodate its size but was willing to tackle this project. Midwest Freeze-Dry in Skokie was up for the job and already had experience with the process.
To freeze-treat a natural history specimen, it first it needs to be enclosed in a protective barrier. In this case we used plastic sheeting because it came in a large enough size to cover the mount, but for smaller specimens plastic garbage bags or freezer grade zipper-closure bags work well. The purpose is twofold: (1) it creates a “sealed” enclosure so that insects cannot spread to other specimens and (2) it creates a moisture barrier so that any condensation that may form during the freeze-treatment forms on the exterior of the barrier and not on the specimen.
Once the bison mount was wrapped, in what resembled a plastic cocoon upon completion, we arranged a delivery date and then booked appropriate transportation with additional people to assist with the move. After the mount was carefully moved onto the truck and securely strapped in for the 6 mile trip north, the next step was to transfer it from our truck to the freezer truck, which was accomplished with a forklift and the help of many people.
Unlike freezing food items at home, to effectively kill insect pests, the specimen has to be exposed to at least two freeze cycles with a thaw in between. The method is pretty simple, the specimen is placed inside the freezer space and the temperature is dropped rapidly and held steady for a set time and then the temperature is gradually increased. After the space returns to room temperature, the temperature is dropped rapidly again for a second cycle and then gradually brought back up to room temperature again. This cycle ensures that any insect pests that went into a dormant phase during the first freeze cycle are “woken up” during the thaw period and then eradicated by quickly dropping the temperature again. The amount of time needed depends on the temperature of the freezer space, the size of the freezer space, what kind of insect pest you are dealing with, and the size and composition of the specimen.
When the allotted freezer time was completed, utilizing more people, two forklifts (one at each location) and a pallet jack, the Bison mount was transported to the museum for its final installation. You can see the Bison mount as well as other specimens from the collection in the exhibit, Food: The Nature of Eating, at the museum.
Amber K. KingView Comments
Assistant Collections Manager