The Monarch Monitoring Project is a long-term study on monarch migration through Cape May, NJ. It is a part of the New Jersey Audubon Research Department, and closely affiliated with the Cape May Bird Observatory.

Wednesday, October 31, 2018

Surprising increase in monarchs

We had just about given hope of seeing many more monarchs in Cape May Point this year, since we have seen very low numbers over the last week.  Gentle northwest winds on Tuesday brought a modest increase in monarch numbers, to our surprise, and it seemed like numbers were increasing throughout the day.

While the seaside goldenrod is still blooming along the upper beach, the monarchs were not found there.  Maybe it was the wind -- the beach is always the breeziest spot -- or maybe the goldenrod isn't offering much nectar.  Thankfully there are many active gardens around Cape May Point that are still filled with nectar-rich flowers, and that's where the monarchs were found.  As a team we tagged nearly 100 monarchs today.

We don't know what's going to happen over the next few days, but the weather is supposed to stay fairly mild, so one more late surge of migrating monarchs may be possible.

We were also surprised today by good numbers of other butterflies.  We saw a sudden upsurge of Red Admirals, including the one shown above, and there were several other species found in the gardens around Cape May Point.  The fresh Question Mark, shown below, was certainly one of the most beautiful.

Sunday, October 21, 2018

Fall Festival Wrap Up

This past weekend, October 19th - 21st, the Cape May Bird Observatory hosted the annual New Jersey Audubon Fall Festival, a celebration of all things migration. Our team had the pleasure of setting up a display at the Cape May Convention Hall, where we were fortunate to meet hundreds of visitors and share the magic of the monarchs.

Two chrysalises emerged during the festival weekend! As usual, this happened when no one was watching.

If you missed our tagging demonstrations and are still looking to see the process in action, this upcoming week (10/22 - 10/25) will be our final week of Triangle Park drop in days. Come to Triangle Park at 1:00 PM Monday through Thursday to send off the final waves of monarchs down to Mexico.  Triangle Park is located at the junction of Lighthouse and Coral Avenues in Cape May Point.

To those of you we met at the festival, thank you for stopping by. We were very pleased to sell out of milkweed seeds and hear about all of the work being done to promote monarch conservation, from gardeners with milkweed patches and nectar sources, to educators who bring caterpillars into their classrooms everyday. Our project relies on folks like you who are truly making a positive impact on the monarchs. We hope to see you at the festival next year!

[Post by Naturalist Lindsey Cathcart]

Sunday, October 14, 2018

Monarch numbers increased on Sunday

We were growing impatient in Cape May, as we heard reports of good numbers on monarchs in Ocean City and Stone Harbor over the last few days, two spots north of us in Cape May County.  Numbers had remained fairly modest here in Cape May Point.  On Sunday they finally started to arrive, and we enjoyed a nice influx of monarchs.

Most of the monarch activity was on the seaside goldenrod, which is now at peak bloom.  Monarchs and goldenrods are easy to see right now along the trails near the dunes at Cape May Point State Park, along the promenade in Cape May City, next to many of the dune crossings at Cape May Point, and in a variety of other locations here at New Jersey's southern tip.

We wondered if monarchs might gather into roosting groups this evening.  When the weather is chilly at night this often happens, and at times in the past we have seen aggregations of many hundreds, even thousands infrequently.  The weather didn't cool much as sunset approached, and many monarchs looked like they would settle in for the night right in the goldenrod patches, but some did fly up into conifer trees near the beach, with a little more than 200 counted shortly before sunset along the trail to the beach across from St. Peter's Church, at the Intersection of Harvard, Ocean, and Lake.  We think that there are more monarchs on their way to Cape May Point over the next day or two, but we can't be sure, and we don't know how long those that arrived on Sunday might stick around.  We'll just have to head out again tomorrow and see what we find.

Friday, October 12, 2018

Looking good for Saturday

A big cold front passed through Cape May Thursday night into Friday morning, bringing strong northwest winds onto the Cape.  Northwest winds trigger all sorts of migration, and more than 5,000 American Kestrels (shown here) were counted from the Cape May hawkwatch on Friday.  Northwest winds are the best for monarch migration, but we saw very few here on Friday -- the winds were just too strong.  Lighter northwest winds are predicted for Saturday, and we have received reports of many monarchs occurring on Friday at Stone Harbor, just 10 miles to the north of us, so there are many reasons to expect a lot of monarchs in Cape May on Saturday.  Come see us if you can -- we'll offer our regular monarch talk and tagging demo at 2 pm in Cape May Point State Park, under the East Picnic Shelter (adjacent to the big hawkwatch platform, across the parking lot from the lighthouse).

Newly tagged monarch takes off from a visitor's hand
at Friday Monarch Tagging Demo.

Wednesday, October 10, 2018

Uncertainly lies ahead

Seaside Goldenrod as seen from the St. Peter's dune walkway, Cape May Point.

Monarch numbers have been modest around Cape May Point this week.  Witness the Seaside Goldenrod along the dunes, as seen above, a favorite nectar source for migrating monarchs.  Only a few monarch have been seen enjoying these nectar-rich flowers.

The current weather forecast shows the edge of Hurricane Michael swinging through Cape May in the near future.  Tropical storms are notoriously hard to predict, but it seems certain that we'll get some effect from this system.  Rain seems almost certain, but if the storms trends south it could just be ¼ or ½ inch, while if it veers a bit further north we could get 4 inches or more.  Some high winds also seem likely, with stronger winds likely to occur if the storm takes the more northerly track.  Most impacts of the storm look like they'll be here between Thursday afternoon and Friday morning.

A strong cold front is predicted to usher the storm out to see, bringing much cooler temperatures and strong northwest winds for the weekend.  Northwest winds are generally the best for monarch migration into Cape May, but the butterflies don't do well in especially strong winds nor in heavy rain.  So we are more confused than ever about the prospects for monarch migration over the weekend.  We've just got to wait and see.

One thing is certain -- this Friday through Sunday, Oct. 12 -14, we'll have our last formal tagging demos at Cape May Point State Park, each starting at 2 pm at the park's East Shelter.  Last Saturday we hosted about 140 people at this program, we're hoping that even more of you will come to see us this weekend!  On the following weekend, Oct. 19 - 21, we'll be participating in the NJ Audubon Fall Festival, with a table at the Cape May Convention Hall and tagging demos at noon on Saturday and Sunday (and perhaps impromptu demos at other times).  You can also meet one of our team members each Monday through Thursday, through Oct. 27, at 1 pm at Cape May Point's Triangle Park (at the junction of Lighthouse and Coral Aves.) for a casual chat about monarch biology and conservation.

Common Buckeyes are still abundant around Cape May Point.
At least these lovely butterflies are enjoying the goldenrod!

Sunday, October 7, 2018

Cape May Monarch Festival today!

The Nature Center of Cape May hosts the annual Monarch Festival today, Sunday Oct. 7.  Our team will be there for tagging demos and an illustrated talk on monarch biology and conservation.  We hope to see you there!  Details here:

Friday, October 5, 2018


Finally, we have had some impressive monarch days in Cape May! This week we have had census numbers exceeding the rest of the season by large margins, with Friday morning's census being our highest yet: 105 monarchs in 20 minutes. The seaside goldenrod has begun to bloom as well, a favorite nectar source for our fall migrants. Keep a look out for monarchs nectaring on the dunes across the point in the weeks to come! 

With this increase in butterflies, we also have more visitors attending our weekend tagging demonstrations (2:00 at the State Park, Friday to Sunday through Oct. 14) One of the things we will always suggest to help monarch populations at these demos is to plant milkweed anywhere and everywhere. Since milkweed is the only plant a monarch caterpillar can eat, they are absolutely necessary for monarch butterflies. Because of this, milkweed has become synonymous with monarchs.

Milkweed is also a host plant for a wide variety of other insects. Planting a milkweed patch creates an entire community of organisms that both depend on the milkweed and each other for survival. If you have a patch of milkweed at home, keep a lookout for these other milkweed dependent bugs, and you can start to look at the milkweed patch not only as food for monarchs, but as a village with many different residents!

Large milkweed bug

  • They do not eat the leaves of the milkweed plant, but use the seeds as their food source
  • Certain populations of large milkweed bugs are migratory, while others are not
  • Like the monarch, the large milkweed bug is toxic to predators

Milkweed leaf beetle

  • While milkweed is a major host plant for these beetles, they also will use some other plants in the larger milkweed family

  • Milkweed aphids

    • Aphids, in small colonies, are very unlikely to cause significant harm on your milkweed plant
    • Unlike most other insects, they give birth to live young
    • Female aphids are able to reproduce without a male, and if needed, one could create hundreds of clones of herself

    Milkweed tussock moth

    • Another milkweed caterpillar, the milkweed tussock moth gains its toxicity to predators from the host plant and retains it to adulthood
    • Like the viceroy butterfly, these caterpillars are a Mullerian mimic of monarch caterpillars

    [Post by Field Naturalist Sarah Crosby]

    Weekend Update

    Monarchs have been drifting out of Cape May over the last two days, and while there are still reasonable numbers around, more are likely to head across the Bay over the weekend. How many new ones will arrive? The migration will continue for a few more weeks, and certainly more monarchs are on their way, but it's impossible to predict when the next big surge will arrive. Wins are expected to blow from the east or from the south over the next few days, and those winds don't typically bring a lot of monarchs onto the Cape, but the usually patterns haven't been holding this year. We'll just have to wait and see.

    Tuesday, October 2, 2018

    Update 10/2/18

    Monarch numbers around Cape May Point seemed to drop gradually over the last few days.  Monday, late in the afternoon, I was netting a few monarchs to tag and many had already been tagged by another member of our team.  The fat measurement on most was high, suggesting they had been feeding, not traveling, over the last few days.  It seems that many other monarchs had crossed Delaware Bay and continued on their southbound migrations.

    Tuesday afternoon, however, I netted several monarchs and most had little or no fat reserve, suggesting that they had been traveling.  This hints at the beginning of another movement of monarchs into Cape May.  We also learned that big numbers of monarchs were seen today at East Point, about 30 miles to our north and another location where migrating monarchs often concentrate.  Typically we have 4 to 6 distinct surges of migrant monarchs into Cape May each fall, so another build-up of numbers is expected.  We're hoping that numbers will increase over the next few days, but we never really know what's going to happen.

    The discovery of monarchs tagged by someone other than our team is always unexpected, and we're delighted when it happens.  Sometimes the tagger came to Cape May -- that's why we ask all visiting taggers to share their tag numbers with us -- but sometimes they come from far away.  Today such a monarch was found, bearing tag code XYW 162.  We hope to learn soon the details of this tagging -- when and where it was tagged.

    Most of the monarchs that I saw today, as has been true for many monarchs over the last few days, were nectaring on the flowers of groundsel-tree, Baccharis halimifolia.  This native shrub is widespread around Cape May and other coastal areas in the east, and it attracts monarchs and many other insects when it's in bloom (see below).

    Unfortunately, the bloom period for groundsel-tree is brief, usually just for a week or less.  It won't be long before these blossoms are finished for the year.  Fortunately, just as its bloom period finishes, the next great nectar source becomes available.  Seaside goldenrod is abundant along the dunes and nearby patches of sandy soil around Cape May Point.  While most of the seaside goldenrod is still in bud, the first few flowers have opened up and the rest should come into bloom within the next few days.  For most of the month of October these flowers will be providing nectar for migrating monarchs.

    Seaside goldenrod in bud (left)
    and beginning to bloom (above).

    We hope that we'll see many visitors coming to Cape May over the next few weeks, and we hope that there will be plenty of monarchs for those visitors to enjoy.  Watch for other butterflies while you're here, perhaps you'll see a gray hairstreak, a common buckeye (they're exceptionally common this fall), or the scarce long-tailed skipper.  There's always plenty to see on a visit to Cape May.

    Gray hairstreak

    Common buckeye
    Long-tailed skipper