Migration Madness

Good news! We were so pleased to have had a handful of healthy and happy Monarchs emerge from their chrysalis. But because we had so few, we quickly released them in the Park so that they could mate, lay eggs, and allow their young to become an integral part of the migration process. Unfortunately, due to the loss of many of our caterpillars we were unable to move forward with our release party. We are optimistic that next year will yield better results!

Monarch Butterfly migration is a spectacular process, but as you may know it poses many challenges to these delicate insects. The fall generation of Monarchs from Connecticut and locations East of the Rockies will spend their winter hibernating in a micro-climate, or specialized environment, in Oyamel Fir Trees located in parts of Mexico. Monarchs West of the Rocky Mountains will generally travel to Southern California where they can hibernate in a similar climate created by Eucalyptus Trees. The specialized zone is created by keeping rain out and heat in. Although it is a different group of Monarchs every winter season, they still choose the same trees to migrate to each year.

The journey that these creatures take is unique to their class, no other insect can travel that far. One obstacle is the weather. If it is too cold they get sluggish and cannot flap their wings. Too hot and they have to stop flying so that they do not overheat. Often they have to stop for water and nectar, which puts them in danger if any enemies are lurking around. A rainstorm can also be deadly. But many do survive the two month journey and reach the safety of these trees! When all of the butterflies over the range of a few days they huddle together in clusters and hang onto the trees for warmth and safety through the season. 

Want to track the Monarchs? Follow the Journey North's interactive migration map HERE!

Chrysalis Alert!

Finally we have caterpillars who have made it to the chrysalis phase! Unfortunately we had some caterpillar casualties due to one of many diseases that Monarchs are susceptible to. Ours were sadly affected by a very fast moving virus called the Nuclear Polyhedrosis Virus. The caterpillars who were separated quickly enough were able to survive and go on to pupate. Let's focus on the positives and learn about the amazing transformation that takes place in this phase! 

Once the caterpillars are big enough, they stop eating. It then forms a protective layer of silk around itself, called a chrysalis. The chrysalis is soft at first, but within an hour, the shell hardens to protect the growing butterfly living inside. It’s green color helps disguise the pupa from predators, but since they are living in our office, we just get to admire the beauty! The pupa, or the caterpillar in chrysalis, remains motionless. Even though the pupa has no eyes, legs or antennae, it undergoes a series of changes so it can reborn as a butterfly. The mouth changes from a milkweed-chewing machine to a straw-like tongue, called a proboscis, that the butterfly will need to sip nectar from flowers. After about 15 days, a butterfly emerges. It takes a few hours before the newborn butterfly can fly because its wings are tiny, wet, and wrinkly. The butterfly pumps hemolymph, a body fluid, into the wings to make them stronger and expand. After it’s wings finally become stable, the butterfly goes off to look for it’s first meal! Butterflies enjoy nectar, a sweet, sugary liquid produced in plants, from several different flowers including red clover, alfalfa, thistle, and wild carrot.

New Developments

At this point our 89 caterpillars are in all stages of larval development. Like people, they grow at their own rate and in their own time; the entire process from egg to adult butterfly taking about a month. As the caterpillars grow and become too big for their own skin they molt, much like a snake does. Between molts, the phases are called instars. Monarch caterpillars have 5 instars in total.

Because they quickly eat their shed skin (it is a rich source of vitamins) before further munching on Milkweed, it is hard to tell when caterpillars have moved into a new stage, but there are other indicators. For example, their color becomes deeper and more rich through each adjustment, they grow thicker antennae to help them find food (although they have 6 pairs of simple eyes their sight is still poor), and more established prolegs, or feet, to better help them grip the Milkweed leaves. Time in each instar stage can range between 1 and 5 days, although it varies with the temperature and light availability. We expect ours to take a little longer to develop because they are being reared in our cooler office climate! At this point we have transplanted the largest of the bunch into a rearing net as they get ready to move into their pupa stage. Check them out in their new digs!

Growing Fast!

Having only been with us for a week, our caterpillars have fattened up quickly! It is natural for them to put on a lot of weight, up to 2700 times their original weight, from the nutrition of the Milkweed leaves alone. What you may not know is that the Milkweed sap makes them poisonous to other animals. To warn predators of their bad taste, nature has equipped them with the black and white striped pattern, a system known as aposematism. Aposematic signals can include coloration, smell, and sounds. This is beneficial to both predators and prey because the predators avoid potential harm, and prey avoid being eaten! 

Why are the Monarch caterpillars poisonous? The Milkweed plant contains a chemical called Cardenolides. This chemical when ingested by the caterpillar in large amounts makes them poisonous to many vertebrates, even as an adult butterfly! It has even been observed that Monarch caterpillars who have ingested Milkweed with higher amounts of Cardenolides, they are less likely to be predated on by animals like birds and mice. 

Take a look at this shot of our growing critters. Hard to believe such harmless looking creatures can be so unfavorable to other animals! 

Here We Grow!

Our Monarch caterpillars have finally arrived! To ensure the highest survival rate they will be reared in a terrarium in Mill River Park Collaborative's office before being released at the Monarch Waystation in the Park's playground in late August or early September. When they are being raised in an enclosed environment cleanliness is very important. The lining of our terrarium will be changed daily because the caterpillar waste or "frass" can become moldy and resulting germs from the trapped droppings can make the caterpillars sick. Yellowing or dry leaves also have to be removed daily, and fresh leaves provided, so that the caterpillars can receive the maximum moisture and nutrition from the plants. The lifecycle from egg hatching to butterfly usually takes about one month, so be sure to check often for updates on our small, new friends! 

Year Two: Awaiting Our Caterpillars!

Here we are in year two of our Monarch Watch project at Mill River Park, and we are currently patiently awaiting the arrival of about 100 Monarch caterpillars from The Monarch Watch! They have lots to look forward to when they reach us; plenty of Milkweed harvested from Mill River Park to munch on and a roomy terrarium to develop in until they are ready to be released. If you followed our blog, which began last summer, you know that we are a registered Monarch Waystation, and each year we hope to release 80-100 Monarch Butterflies in the heart of Stamford, CT.

Already we have been seeing Monarchs in our riparian meadow habitat, doing their due diligence by feeding on nectar plants and pollinating all along the way. Their attraction to the Park lies in the several pollinator friendly species cultivated here such as Scarlet Bee Balm, Purple Cone Flower, New England Aster, Columbine, and of course, Milkweed. Adult female Monarchs are selective in that they will only lay eggs on the Milkweed plant, and the resulting larva can only feed on the leaves of the Milkweed plant. Thus growing this particular plant in your habitat is key to attracting these critters.

Females use a combination of visual and chemical cues to find Milkweed. Upon their migratory arrival in the early spring from California and Mexico, it is imminent for them to find this particular plant in order to lay their eggs before they die and a new generation can begin.

Check back each week for a Mill River Park Monarch update! We will be sure to keep you in the loop throughout their development into adult butterflies. In the meantime be sure to take a walk through the Park and scout out the adult Monarchs already out and about, and if you snap a picture of a Monarch, please send it to photos@millriverpark.org. 

Butterfly Release

Last night we released around 30 monarchs into our certified Monarch Waystation in the Butterfly Hill playground garden. Most of them enthusiastically took off and a few hung around to taste test the flowers that have been strategically planted for butterfly enjoyment. These monarchs will soon begin their southern migration and head to the Sierra Madre Mountains in Mexico for the winter. Monarchs can travel, on average, 50-100 miles a day. The butterflies we released last night will be the same ones who make it to Mexico for the winter, but the ones that return to our waystation in Stamford next summer will be 3-4 generations later of their offspring.

If you want to create your own Monarch Waystation and raise some butterflies next summer, visit Monarch Watch to get important information and kits.

We had a great time last night with our members and some of their kids for our Butterfly Release Party! Here are some pictures from the evening.


Butterflies, everywhere!

It's been a month since 100 centimeter-long caterpillars arrived at our office in downtown Stamford, and now we've got butterflies everywhere! As can be expected, we had some caterpillars who didn't make it all the way to adulthood, as well as about five that developed much faster than the rest and have already been released. But as of Monday morning, we have 15 Monarchs in our office with another dozen or so ready to emerge at any moment.

This week we will be hosting a members-only Monarch Release event where a large swath of butterflies will be released simultaneously in our newly christened Monarch Waystation. Basic membership costs $25 and gives you access to special events such as this, as well as multiple other benefits. Contact Emily Rosenthal at emily@millriverpark.com to learn more about how you can become a member.


Fascinating but Gross: The Science of Metamorphosis

Have you ever wondered exactly how a caterpillar changes into a butterfly? We've been pondering this question, particularly since when we leave at night they are still caterpillars and when we return in the morning they are chrysalises. What happens overnight?

Well the answer is both incredible and disgusting. Essentially the caterpillar melts in the beginning stage of metamorphosis. To get to the pupae stage a caterpillar has to digest itself, turning into what Scientific America terms "caterpillar soup" inside the chrysalis. The genetic makeup for the butterfly has been hiding inside the caterpillar all along, and now it comes out. These are called imaginal discs, and they feed off the rest of the caterpillar mush to grow into it's final butterfly form.

So what comes out as a butterfly has a completely different genetic makeup than it's caterpillar origins. Want to see if happen? Here's a great time-lapse video from Youtube:

 It's an amazing snippet of the monarch caterpillar lifecycle to witness, but honestly it's still gross.

Changes Abound

 Our taped chrysalis

Our taped chrysalis

Wow, what a difference a 3-day weekend makes - we left Friday with 2 chrysalises and come back to 27!! There are also still about 40 caterpillars munching away and getting bigger each day.

One thing we learned over the holiday weekend is what to do when a chrysalis falls. The chrysalis are attached to the ceilings and walls of the emergence chambers by a small silk button, woven by the caterpillar. These can be moved after they've hardened, about 48 hours, but should be left alone until that time.

So what happens when you find one on the bottom? This is a problem when the chrysalis is still soft. If left lying on its side then it can flatten and result in serious development problems. You should immediately re-attach the chrysalis to the side, either by attaching the silk pad to a cotton ball and hanging that, or taping the exposed silk pad to the side (don't tape the chrysalis).

For our trouble shooting we went with tape. The chrysalis silk pad wasn't really latching on to anything so we taped it to the side of an emergence chamber. Unfortunately we didn't have tweezers so we very delicately used our fingers on the surprisingly soft chrysalis. We hope this one pulls through!

Weekend Update

A quick update on our little friends before the holiday weekend:

A few of the caterpillars have shed their skin and are now hanging in their hardened cocoons. There are a few others preparing to enter the chrysalis stage, and it seems like many are just a couple of days away. We have transferred all but the very smallest of the caterpillars out of the terrarium and into special nets, known as emergence chambers, made for caterpillars and butterflies, which are now hanging throughout the Mill River Park Collaborative office. I apologize for the picture quality below, but I didn't want to open the net and disturb the cocoons.

Caterpillars and Chrysalises

Most of our many-legged friends have now reached over an inch in length, have turned dozens of milkweed leaves into a considerable amount of body fat, and have developed a bright black and yellow stripe pattern. And, as of this morning, our first caterpillar has begun the process of pupation!

When butterfly larvae, a.k.a. caterpillars, have finished growing they spin a small silk button on top of their container. Then they hang upside down from the button in a J-shape and prepare to molt to the chrysalis. The caterpillars expand until their skin splits and reveals a green cuticle, which then hardens into the chrysalis, or cocoon. In a room temperature setting, it takes approximately two weeks for the butterflies to emerge from the cocoons.

Now, we need to carefully remove the caterpillars from the terrarium and place them in special nets made for chrysalises and emerging butterflies.

Growth Spurts!

August 28, 2015

It has now been ten days since our caterpillars were delivered and their growth rate has been remarkable. After a week and a half of munching on milkweed leaves, stems, and pods some of the caterpillars have more than quadrupled in size. Monarch caterpillars go through five stages of growth, known as instars, during which they’re storing fat and energy that will carry them through their pupae stage. Currently, most of our caterpillars are in the second or third instar stages.

There are three subspecies of Monarchs, with ours belonging to the subspecies Danaus plexippus. These little guys are native to North America but can now be found as far away as New Zealand and Spain. Monarchs are famous for their massive annual migration across North America. Every year millions of Monarchs that live east of the Rocky Mountains head south to the Mariposa Monarca Biosphere Reserve in Mexico. In the spring, an all new generation of butterflies return north to the feeding grounds of their ancestors.

Check back next week for an update on our caterpillars as well as more information about Monarch butterflies and the Waystation project.

Our Monarch Watch Begins

If you’ve been following Mill River Park’s Facebook or Instagram accounts this past week, you’ve probably seen pictures of tiny caterpillars crawling all over leaves. These little critters are Monarch Butterflies in the making. Monarchs are a species of special concern, and for this reason there are a number of organizations dedicated to their protection. Mill River Park is dedicated to becoming a certified Monarch Butterfly Waystation, hopefully attracting Monarchs during their migration between Canada and Mexico.

I’d like to open our blog with some background on this project. Earlier this summer our Mill River Stewards identified two locations in the Park that are suitable habitats for Monarchs. These areas are high in milkweed, where Monarchs lay their eggs, and nectar plants that adult butterflies use as food. Later in the summer, a volunteer group from Pepsi Co. came and planted even more nectar plants in these locations. We then submitted a request to an organization called The Monarch Watch, who approved our sites and sent us 100 caterpillars.

Now, we are in the process of incubating the caterpillars in a controlled habitat. We could have released them into the Park, but for their protection we are keeping them in a terrarium until they’ve metamorphosed into adult butterflies. The entire process should take about one month. Check back here in a couple days for another update, and also keep an eye on our social media accounts for more pictures!

If you’re interested in starting your own Monarch Waystation, check out monarchwatch.org to learn more about what you can do