The warm, sunny, low humidity days we've been having are as good as it gets for being outside and looking for late season butterflies. While the overall numbers and species are definitely down, there are still plenty of awesome butterflies to find including the less common southern ones. I took walks at the park on Saturday and Monday and found great butterflies both days. With less butterflies on the wing, it takes a little more searching to find them, but the effort will be worth it.
As I've mentioned over the past few updates, despite less overall activity, in some ways the most exciting butterflying of the year is upon us. Now is definitely the time to look for the really awesome southern butterflies that move north into New Jersey in late summer and early fall. These butterflies can't survive our cold winters and it is unclear why they do this. But they do and often in large numbers. This type of movement is known as "emigration." It is also the time to look for migrating monarchs and the final flight of many of our butterflies that we won't see again until sometime next year.
If you have been visiting the Butterfly Park throughout the year, you may have noticed how some butterflies are there all the time, while others seem to appear and then disappear and yet others are there, gone for a while and then are seen again later in the season. Flight dates for butterflies are called flight phenologies, the scientific term for when they are flying. Some of our butterflies have only one adult flight period during the year. These butterflies are called univoltine, reflecting this type of life history (Uni = one). These are butterflies that spend the rest of the year in one of the other life stages, as an egg, caterpillar of pupa with the adults on the wing only one once. But many of our butterflies are bivoltine meaning that they have two distinct times of the year when adults are flying (Bi = two) punctuated by a period when they aren't. Some of the butterflies we are seeing right now at the park are the second adult generation of the year and are therefore bivoltine. The first generation of flying adults for these butterflies was on the wing in late spring or early summer, followed by a lull until the next generation matured and took flight now. Depending on the species, these late summer adults may either lay eggs that will overwinter and hatch in the spring, lay eggs that will quickly develop into a caterpillar or pupa and overwinter that way, or even overwinter as adults in some protected place. we also have butterflies like the common Cabbage white that are probably mutli-voltine reflecting adult generations multiple times during the year which is why we see them flying from early spring until late fall.
Like the last two weeks, I went to the Butterfly Park over the past few days looking for "southern" butterflies and I was lucky to find one of the best - the giant, fluorescent yellow Cloudless sulphur. This big beautiful bright yellow butterfly emigrates north into New Jersey in late summer and early fall. Once you know what to look for, they can be easily recognized by their size, direct powerful flight and bright yellow color. They are often seen as a fast flying bright yellow butterfly. This was only the second time that I've seen one at the Park! Cloudless sulphurs have been quite common in New Jersey over the past few weeks so finding one wasn't completely unexpected.
This week and for the next few on cold fronts, is also the perfect time to look for migrating monarchs as they head south to their wintering grounds in the mountains of Mexico. They migrate just like birds on late summer and early fall cold fronts with northwesterly winds. There were plenty of monarchs at the Butterfly Park on Saturday and Monday nectaring on the butterfly bushes and goldenrod. There was also a big fat monarch caterpillar on one of the milkweed plants along the main trail happily munching away in plain sight. With all the monarchs at the park, keep an eye out for any with small round white tags on them. If you see one with a tag, try to get a photo of the tag or record the number on it. These tags are part of a huge Citizen Science project that has been going on for more than 50 years to unravel the migration patterns of the monarch. If you are interested in purchasing these tags and putting them on monarchs to help scientists plot their migration, visit MonarchWatch.org
Amazingly, the East Brunswick Butterfly Park turns 10 this year! Kudos to all the volunteers that have helped make this park so special. Despite its small size and location in a heavily developed area, the park provides lots of opportunities to find a wide variety of butterflies throughout the spring, summer and fall. It just takes a little looking.
Throughout the years, dozens of species of butterflies have been seen in the park. The Friends has developed an Online Field Guide to them that has photographs, ecological notes and tips on how to tell butterflies apart that look similar. The park also has a Facebook page so that everyone can share what they find at the park.
While the Butterfly Park is too small to have much in the way of rarities or butterflies of special habitats, it offers a convenient respite and an opportunity to find many common species right in the middle of 50,000 people. And since "butterflying" is a lot like a treasure hunt, you just never know what you might find even in a small place like the East Brunswick Butterfly Park.
Each year we try to do something new with the Park. This year, with the help of the Patch, we are posting what is being seen at the Park each week. We can't always get there ourselves to see what is flying, so please share your observations and photos with us either on the Facebook page or firstname.lastname@example.org.
So, what's flying now? Despite the leaves starting to change and fall being upon us, don't stop looking for butterflies at the park yet or you will miss the opportunity to see lots of migrating monarchs and plenty of other species for the last time until sometime next year. On warm sunny days there are still plenty of butterflies to be found at the park. This is also the time to look for southern strays like the big yellow Cloudless sulphur. It is also a good time to find the final adult flight of many of our butterflies.
This week the Butterfly bushes are still flowering and attracting butterflies, although the number of blossoms are diminishing. The pink joe-pye-weed, while way past peak, is still attracting some butterflies. The bright pink sedum are now in full bloom and are a magnet for skippers. And, the meadows are filled with bright yellow goldenrod flowers and these are a fantastic magnet for butterflies and other insects, day and night.
As in past weeks cabbage whites are still common and can be found on any warm sunny day. There are also a few Silver-spotted skippers along with plenty of other smaller skippers including; Sachem, Wild Indigo Duskywing, and Peck's. With the exception of the big quarter-sized Silver-spotted skipper, these are all the small, dime or nickel-sized triangle-shaped butterflies that are seemingly everywhere. They get their common name of "skipper" by their constant habit of "skipping" on and off of the flowers. They are incredibly active little butterflies and although at first glance may seem brownish, are worth a closer look. Many are beautifully colored and patterned. Even with their overall numbers down, they are so abundant that they simply cannot be missed when you visit the park.
The diversity of butterflies at the park still continues to be impressive even if overall numbers are down. Migrating monarchs are common. On Saturday and Monday I probably saw a dozen. I also saw a Common buckeye and a few clouded sulphurs nectaring on the goldenrod, a few very beautiful fresh Red-banded hairstreaks, a really beat up Pearl crescent, two Red-spotted purples (look for them on the rotting crabapples near the top of the cinder trail as it enters the meadow), a Gray hairstreak, a Question mark, a Summer azure and a few Tiger swallowtails. The little Eastern tailed blues also continue to be common but not like last week. I also saw a Mourning cloak fly by toward the woods without pausing. I'm certain if I was able to spend more time, I would have been treated to more species.
If you go to the park looking for butterflies, try and pick warm afternoons with little wind. Scan the meadows and walk the woodland trails and let us know what you find. Looking for butterflies is a lot like a treasure hunt. You never know what you might find. Not every butterfly will be evident or just flying around in plain sight. Finding butterflies takes a little practice, but once you begin to know what to look for you will be amazed at what is at the Park. Happy Butterflying!