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.

Saturday, September 29, 2012

Roosting spectacles

It was a great day in Cape May, both for birds and monarch butterflies.  The afternoon saw many monarchs streaming down the dunes into Cape May Point.  A number of sizable roosts were found, the one shown below with about 3,000 monarchs.  Monarchs will surely be plentiful in the morning on Sunday, and with gentle north winds forecast for tomorrow, we could see monarchs departing for Delaware or we could see monarchs arriving from the north to spend time at Cape May Point.  What actually will unfold tomorrow?  We don't know for sure, but I'll bet there will be monarchs both leaving and arriving, and that Sunday will prove to be another spectacular day for observing monarchs in Cape May.  Join our team for the tagging demo at 2 pm at the East Shelter, Cape May Point State Park.

 Two shots of one of the big monarch roosts along Lincoln in Cape May Point.

Tonight's sunset over Delaware Bay.

Get thee to Cape May

Saturday dawned to northwest breezes and high clouds, a perfect fall day in Cape May.  Birders all over town are going nuts with great numbers of warblers in the trees and raptors migrating overhead, but monarch fanciers are also being rewarded today.  We were surprised by good numbers of monarchs swirling over the dunes of Cape May Point, with more seeming to stream in from the north all morning.  Roosts are beginning to form already, but today the monarchs seem to be gathering in the conifers -- pines and junipers (also known as cedars) near the dunes.  The first flowers of seaside goldenrod have now opened, providing excellent nectar for monarchs along the dunes and on the upper beach.  The birds and butterflies agree -- today's a day to be in Cape May.  Come and join them if you can.

Friday, September 28, 2012

Weekend update

While it's still very easy to find monarchs around Cape May, numbers have clearly declined over the last two days, as was expected with the mild south winds.  Current weather forecast is for rain through much of tonight with the cold front finally pushing through late at night.  Winds are forecast to blow from the northwest all day tomorrow, bringing with them the possibility for another major influx of migrating monarchs into Cape May.  We'll strive to update quickly if we see a major arrival event beginning.

We will have our usual tagging demos at the South Shelter of Cape May Point State Park at 2 pm both Saturday and Sunday afternoon.  Today our audience for the demo exceeded 100 for the first time this year, including many young monarch enthusiasts.  Join us tomorrow to make it an even bigger crowd, the more the merrier!

MMP Director Dick Walton begins the tagging demo with a description
of our research project.
Some eager young biologists took notes on Dick's comments.

Two enthusiastic young monarch biologists provide a launching pad for
a newly tagged monarch.

Thursday, September 27, 2012

Thursday morning

Many monarchs were seen above the dunes at Cape May Point this morning.  Many seemed to be milling around in the air above the dunes, testing the winds.  Some would fly out over Delaware Bay a short distance only to return.  By about 8:30 am we started to notice good numbers heading well offshore and probably committing to fly across the Bay.  There were still reasonable numbers of monarchs around last night's roosts and in the air above the residential neighborhoods.

The cold front appears to be stalling out, and weather forecasts are changing every few hours.  The winds are starting to switch around to the NW right now, which could trigger monarch movement both away from Cape May and also into the area from the north.  Most forecasts currently seem to suggest a stalling of the front later today back to our north, with more southerly winds this afternoon and tomorrow, but with northwest winds on Saturday.  If this forecast holds, monarch numbers will probably dwindle today and tomorrow, with a chance for another major influx beginning on Saturday.  As always, we will report back with observations that we make, which are (naturally) more reliable than our speculative predictions.

Wednesday, September 26, 2012

Wednesday update and a bold prediction

The news for Wednesday is much like Tuesday's news.  Strong south winds seem to have monarchs unwilling to leave Cape May Point.  Again we are seeing many monarchs around the Point and the best spots seem to be trees with lots of English Ivy vines.  Much of the ivy is in bloom, providing nectar, and the ivy-covered trees seem to offer protection from the winds.  For the last several nights we have seen many small roosts of 100s of monarchs at scattered locations around Cape May Point.  Roosts can be anywhere, but check especially areas where tall trees are covered with ivy vines.  Some groves of bigtooth aspen have also housed roosts.  We know of roosts on Stites, Yale, Cape, Princeton, Cambridge, East Lake, and Pearl Streets.

Monarchs amidst English Ivy flowers.
Now for the bold prediction, which may or may not prove to be true.  Winds are predicted to shift around to the north overnight.  Tomorrow morning, if the winds aren't too severe and if they are blowing from the north, there could be a major exodus of monarchs from Cape May towards Delaware.  The first two or three hours of the day could be when many thousands of monarchs will be seen leaving Cape May and flying out over Delaware Bay.  Head to any of the dune crossovers in Cape May Point or just walk the beach early tomorrow morning and perhaps you'll see a major departure event.  I think that's where I will be doing at about 7 am tomorrow.  Maybe I'll see you there.

We have been tagging hundreds of monarchs in Cape May this fall.
If you see a tagged monarch, try to get the 3-letter, 3-number code.
This one is RNY 582.  Report the tag number, date, time, and location
to Monarch Watch via or call 1-888-tagging.

Tuesday, September 25, 2012

Tuesday midday update

Moderate SW winds are keeping a lot of monarchs around Cape May Point, but not many are visiting gardens, again the hotspots are tangles of English Ivy.  It's a bit ironic, as the ivy is not native and somewhat invasive, yet it is blooming profoundly around Cape May Point right now and the monarchs seem to be enjoying both its nectar and the shelter provided by its dense foliage.  It seems that there were many small to mid-sized monarch roosts all around Cape May Point last night, both in ivy and in groves of bigtooth aspen.

Monarchs amidst the flowers of English Ivy.
Other butterflies are also enjoying the ivy nectar; here it's a buckeye ...

... and here a Viceroy.


Monday, Sept. 24 was a banner day for monarchs in Cape May.  Our census came up with about 481 monarchs per hour, and for most of the day monarchs were concentrated along the beach and primary dune, a habitat not well covered by the census.  Monarchs were observed streaming down the dune from Cape May west to Cape May Point, but no major exodus towards Delaware was observed.

So what about Tuesday?  Predictions are dangerous -- these insects fool us sometimes -- but I'll offer my best guess.  There will surely be lots of monarchs around Cape May on Tuesday morning, members of Team Monarch watched them settle into small roosts all over Cape May Point last night.  Winds are predicted to blow at 10 to 20 mph from the southwest today, and if this prediction holds, we aren't likely to see many more monarchs arriving into Cape May, but not many of those who are here are likely to depart and cross to Delaware into this headwind.  My best guess is that there will be good numbers of monarchs feeding on whatever flowers they can find around Cape May Point.  Check the gardens, patches of English ivy, and also check the dunes -- the seaside goldenrod should begin to bloom any day now, and monarchs love the nectar from this beautiful native plant.

Watch for another post at the end of the day to see if my prediction is anywhere close to correct.

Monday, September 24, 2012

Lots of monarchs

Today -- Monday, Sept. 24 -- we have lots of monarchs around Cape May Point.  Most are along the beaches and dunes, though many are also clustered in patches of English Ivy, such as those in vacant lots along Stites Ave. and in various spots near the dune line.  Surprisingly there are not many monarchs in the gardens.  Don't know what they'll do next or how long this surge will last, but we will keep reporting back to the blog frequently.  Thanks to MMP volunteer Paige Cunningham for checking the Point thoroughly this morning and providing this information.

Sunday, September 23, 2012


Sometimes when there are a lot of monarchs around Cape May Point we'll find areas where many are clustered close together in an overnight roost.  This evening Michael O'Brien found a roost of about 1500 monarchs along Cambridge in Cape May Point.  All signs point toward there being lots of monarchs around Cape May on Monday, but the butterflies do fool us sometimes, so nothing is guaranteed.  Still, if you're near Cape May tomorrow, come visit the gardens at Cape May Point and you're likely to see lots of monarchs.


Monarch numbers around Cape May were low to moderate all morning, but this afternoon we have seen significant numbers arriving into the area, most moving westward along the dune line.  If this continues we could have some roosting in Cape May Point tonight and perhaps very good numbers tomorrow.  We will continue to post updates.

Cold Front

A big cold front passed through Cape May last night (Sept. 22/23).  Sometimes big flights of monarchs come in the few days after cold fronts such as this, but it's never completely predictable.  We will post regular updates once we have had a few hours to make observations.  Stay tuned!

Saturday, September 22, 2012

Tagging demos underway

The monarchs are migrating through Cape May, meaning the time has come for our annual series of Monarch Tagging demos.  We started on Friday, September 14, and will conduct one of these fun sessions every Wednesday, Friday, Saturday, and Sunday until October 14.  Occasionally we will give a special tagging demo for a visiting group or a special event, and our team gives impromptu tagging demos around Cape May Point almost every day.  The scheduled demos begin at 2:00 pm and are held in Cape May Point State Park at the East Picnic Shelter, which is adjacent to the famous Hawkwatch Platform.

Each demo begins with a short talk about monarch biology and migration, the research efforts underway at Cape May, and some ways that every citizen can help conserve migratory monarchs.  We then split into smaller groups to show our guests how monarchs are tagged.  The program usually lasts 30 to 45 minutes, though members of Team Monarch usually stay longer to answer questions and chat with other monarch fans.  There is no fee for the program, though contributions are accepted (and we offer a few thank you gifts for contributors).

Here are some action shots from recent tagging demos.  Thanks to Amy Gaberlein and Scott Whittle for sharing some of the photos posted here.

Julia Druce, our 2012 Intern, explains the research protocol to a group.
Louise Zemaitis, longtime Field Coordinator for the Project, works with part of the group.
Louise shows everyone a sheet of monarch tags.
Julia works with others from the group.

She shows how to place the tag on a monarch's wing.

Voila!  A tagged monarch.
We often have project volunteers helping with the demos.  Here Lynn Lee tags a monarch while visitors watch.
Gayle Steffy has been studying monarchs for many years, helping us at Cape May and at other sites across the mid-Atlantic region.
Mark Garland helps at many of the demos, too.

Everyone loves a close-up look at a monarch butterfly, soon to be released to continue its journey to Mexico.

Louise Zemaitis releases a tagged monarch onto the hand of one of the demo visitors.  Moments later it was airborne.

Thursday, September 20, 2012

Monarchs and Mimicry

Yesterday while tagging in backyard garden at the Point, Lynn (the newest member of the Monarch team) spotted a Viceroy, which was perched on the same patch of blooming ivy where we had observed many Monarchs. I thought this was interesting because not only had the Viceroy obtained protection from predators by copying the Monarch's black and orange coloring, but he was further protected by hanging out with an entire swarm of Monarchs. But this Viceroy was also helping keep the Monarchs safe from predation! How did this work? Monarchs are poisonous to nearly all vertebrate predators due to a collection of heart toxins that the Monarch larvae acquired from their hostplant, milkweed. The Monarchs advertise their toxicity with their brightly colored wings. It only takes one bite of a Monarch to teach birds or other predators to avoid orange and black colored butterflies! And so, a bird who has learned to avoid Monarchs will also avoid Viceroys, who have evolved to copy the appearance of the Monarch to take advantage of that advertised chemical toxicity (Batesian mimicry). At least that is how the story went for many years. Recently, scientists have determined that many Viceroys are poisonous in their own right, especially those whose larvae fed on willows and poplars high in salicylic acid. So it now seems that the Monarch and the Viceroy are both mimicking one another! The Monarch gains more anti-predator protection by looking like a poisonous Viceroy, and Viceroy is protected by looking like a poisonous Monarch (Mullerian mimicry). See the original sources: Experimental studies of mimicry in some North American butterflies: Part I. The monarch, Danaus plexippus, and viceroy, Limenitis archippus archippus & The viceroy butterfly is not a batesian mimic

On the Monarch numbers front, yesterday was a very good day (387 Monarchs/hour). The beginnings of several roosts in the neighborhood around the Point were observed around 4:30 pm. You can now check out the day's Monarchs per hour rate at our website, MMP Data Page, which will be updated by approximately 6 pm EST daily.

Friday, September 14, 2012

Tagging Demos Begin Today!

I'm a little late with this post, but just wanted to let everyone know that Monarch tagging demos have begun. They will be held every Wednesday, Friday, Saturday, and Sunday at 2 pm, (through October 14th) at the East Pavillion next to the Hawk Watch platform in the Cape May State Park. Demoes begin with a brief talk about Monarch biology and conservation, followed by tagging of Monarchs. Information pamphlets and Monarch merchandise will also be available. Today's demo was a lot of fun, with people of all ages taking part.

Monarch numbers are down again, although you can certainly still find sizable bunches of Monarchs if you know where to look (i.e. gardens with good flowers for nectaring). There are rumors of a northernly wind this weekend, which would hopefully bring in a new batch of Monarchs to Cape May. Over all, people are reporting good numbers of Monarchs in the northeast but poor numbers in the midwest. What this means for the Monarch population as a whole is yet to be seen.

While you are waiting for the next wave of Monarchs to come in, go check out the Monarch displays and tanks at both the Cape May Bird Observatory and the Nature Center of Cape May!

Tagged Monarch, with shadow of tag visible through the left hindwing

Thursday, September 13, 2012

Good Monarch Numbers Yesterday

Feeding frenzy on Joe-Pye Weed (Eutrochium)

Hello! Monarchs were here in massive numbers yesterday. Up at the Hawk Watch, they were counting thousands of monarchs as the flew along the dunes and joined the enormous number of dragon flies hovering over the land. The Monarchs were so dense in the gardens that plucking them off plants with bare hands was your safest bet, or else your net would trigger a mini tornado of orange. Thank you to my friends at the Hawk Watch used their days off to help me tag Monarchs! Numbers of Monarchs were certainly down by the mid-afternoon; the wind moved from the north to the south as well so today might not be quite as spectacular as yesterday. But it will still be a great day to look for them, as well as all the other butterfly species that are thriving in the Northeast this year! Also check out the Cape May State Park to search for possible Monarch roost formations.

More photo highlights from yesterday:
Monarchs going wild on some near-dead plant, which may have retained some water from the morning's watering

Red Admiral doing its best to blend in with tree bark

Tuesday, September 11, 2012

They're Here!

Just a brief post to say the Monarchs were streaming into Cape May Point today! A bunch of friends helped out with the tagging and it was all we could do to keep up with the influx of Monarchs into the yard. Tomorrow I'll report if the numbers are staying up and if the Monarchs are hanging around or continuing their journay across the bay. A Question Mark and a Gray Hairstreak were also seen today, as well as the visitors from the south, the Long-tailed Skipper and the Ocola Skipper. Stay tuned!

Friday, September 7, 2012

Monarchs and Unusual Coupling

Hello! There was a small group of Monarchs out flying today in the sunny weather but I don't believe a  large influx of new migrants has arrived yet. The distribution of wing wear seem fairly evenly distributed between older, more worn individuals and younger, fresher looking ones. However, females were finally out in larger numbers today, with approximately 1/3 of the local population being female, going by my tagging results. As we all know, if there are males and females around, then there's going to be mating.

Scene 1a: Clearly a male on top
Scene 1b: RNX022 on bottom, also clearly male
Scene 2: RNX022 pinned to ground by another male
Enter poor male RNX022. When I tagged RNX022 this morning, he wasn't doing so hot. Perhaps this was literally true, as I held him in the shade for a little bit before tagging him, but over all he was doing poorly, with tattered wings, sluggish flight, and difficulty holding on to the Joe Pye Weed. When I came back to the same yard in the afternoon, I found RNX022 clinging to a plant as another male Monarch seemingly tested Mr. RNX022 receptivity to mating. This was obviously an unsuccessful endeavor!

A little bit later, I found RNX022 pinned on the grass by another butterfly, which could be another male. Male monarchs will force females who are not receptive to their courtship displays into mating by sitting on them! Certainly this male seemed to be performing the "take-down" maneuver. So why was RNX022 being targeted by other males as a potential mate? What cues was RNX022 sending out or failing to send out that made others mistake him for a female?

For more information on mating, see the paper
"How Often Do Males and Females Mate, and What Affects the Timing of Mating?"

Edit 09/08/12: I've been reading "The Last Monarch Butterfly" by Phil Schappert, which says that larger male may attack smaller males and that male-male interactions are common. However, these interactions are not described in the book so I still don't know if this was simply one of those interactions or if it was truly a case of mistaken identity.

Wednesday, September 5, 2012

Waiting on the Monarchs & Imperial Moth Larvae

Imperial Moth larvaeHello! Just a few Monarchs have been seen consistently during each car census run this week. For the past couple of days, the winds coming out of the south and east, as well as the overcast weather, have prevented the Monarchs from coming to Cape May in any greater numbers thus far. We are looking forward to north winds, which the Monarch will exploit to carry them southwards towards us without any additional expenditure of energy on the their long journey to the overwintering sites.

Quite soon, there will be Monarch larvae munching away in the terrariums at the Cape May Bird Observatory! In the mean time, stop by the CMBO to check out the enormous Imperial Moth larvae that a local moth-er brought it. These particular larvae are gorging themselves on sweet gum, although they will also feed on other trees. It is very important for these guys to eat as much as possible because as adult moths, they will not eat! Quite soon, these larvae will bury themselves in the leaf litter and pupate, spending the winter protected in the ground. (See for more information.)

Other species seen this week include Black Swallowtail, Eastern Tiger Swallowtail (including an enormous individual with wingspan ~6 inches), Spicebush Swallowtail, Painted Lady (in great numbers!), American Lady, Cloudless Sulphur, Common Buckeye, and Long-tailed Skipper.

Saturday, September 1, 2012


It's the first of September, day 1 for the 2012 field season for the Cape May Monarch Monitoring Project (MMP).  Monarchs are here, in fact we have a mix of two generations that we're seeing around Cape May right now, ones that have begun the long trek to the wintering grounds in the mountains west of Mexico City, and those of the last generation that will not depart for the tropics.

One of our favorite study sites is the Cape May Point garden of Bill & Edie Schuhl, who are great supporters of our project in many ways.  The "tagging bench" is back out for the season.  In the photo below, MMP Field Coordinator Louise Zemaitis and 2012 Intern Julia Druce are tagging monarchs while chatting with Bill & Edie.

Julia comes to the MMP with lots of experience working with lepidoptera in both field and laboratory settings, plus a very strong academic background.  But she has never tagged monarchs before.  It didn't take her long to learn, however.  Below she shows off the first monarch she tagged today; maybe this one will be found in Texas later in September, or maybe even on the wintering grounds in Mexico later on.

Autumn brings other butterflies into Cape May.  We're eager to watch for southern species that disperse northward in late summer and early fall.  This year we are already seeing many Cloudless Sulphurs (Phoebis sennae) and Little Yellows (Pyrisitia lisa -- older books called it Eurema lisa).  And today, in the Schuhl's garden, I saw my first Long-tailed Skipper (Urbanus proteus) of the fall; its photo is below.

And for those of you who like to enjoys butterflies AND birds, I'll mention that the annual hawk count also began today.  This Peregrine Falcon spent much of the morning on the water tower at the old Magnesite Plant near Sunset Beach.
Keep watching the blog for more updates!

Mark S. Garland
MMP Communications Director