Peters Hill Fall Bird Walk

Twenty-three people joined me on this gray morning for a walk on Peters Hill in the Arnold Arboretum, looking and listening for birds.  It was slow going, with no fall warblers seen and several winter species still to arrive.  Our only unusual bird was seen by part of the group before it flew off; a Yellow-bellied Sapsucker.

Male Yellow-bellied Sapsucker, showing the yellow cast on the breast, the distinct white shoulder patch and the red throat and crown characteristic of the species.

The other woodpecker was seen near the end of the trip; fortunately it stayed long enough for most to see it:

Male Red-bellied Woodpecker. This woodpecker is more common than the Sapsucker seen above, as it has moved up from southern areas over the last several decades due to global warming.

Far and away the most common species we saw was the American Robin; most were feasting on the abundant fruit on crabapples and hawthorns on the hill.

The American Robin has an estimated global population of 320 million, almost exclusively in North America.

We also saw several flocks of House Finch feeding actively on the fruit trees.

This photo of three House Finches shows the strong color differences between the drab gray female, left and the rosy red males.

Some in the group saw the other common resident finch in the Arboretum, American Goldfinch.

American Goldfinches lose their bright yellow coloration in the fall and winter.

We finished the walk with some good views of Northern Mockingbirds.

Northern Mockingbirds have long tails, and show distinctive white wing patches in flight.

Based on my scouting expeditions on Peters Hill before this walk, I knew the birding was not likely to be great, so I brought along a “prop” I found the day before:

In the closeup images of this Baltimore Oriole nest you can see the incredibly intricate weaving of the outside fibers and the rusty grass lining inside. How the female bird manages to put this nest together in about a week, and have it hold up through the bustle of four young birds plus herself for at least a month, defies understanding.

My other Arboretum bird walk scheduled two weeks ago was cancelled due to rain, and today we ended in misty rain as well. Despite the limited species seen, and the weather, it appeared that most of the birders enjoyed themselves.  Here is our list for the walk:

Arnold Arboretum, Suffolk, Massachusetts, US

Oct 14, 2017 8:00 AM – 10:00 AM

Comments:     60, cloudy

16 species

  • Red-tailed Hawk  1
  • Rock Pigeon (Feral Pigeon)  1
  • Mourning Dove  7
  • Red-bellied Woodpecker  1
  • Yellow-bellied Sapsucker  1
  • Blue Jay  12
  • Black-capped Chickadee  1
  • Tufted Titmouse  1
  • American Robin  60
  • Northern Mockingbird  2
  • European Starling  3
  • Chipping Sparrow  6
  • Northern Cardinal  5
  • House Finch  20
  • American Goldfinch  2
  • House Sparrow  2
  • View this checklist online at

This report was generated automatically by eBird v3 (

On Sunday December 10th I will lead a walk along some of the ponds of the Emerald Necklace:

This 90-minute walk will focus on waterfowl and other winter species in the ponds and adjacent woods of the Emerald Necklace.  Suitable for beginning birders as well as more experienced birders.  The walk is co-sponsored by the National Park Service/Frederick Law Olmsted National Historic Site, the Brookline GreenSpace Alliance and the Emerald Necklace Bird Club. Meeting Place: Parking lot for Daisy Field, Olmsted Park on Willow Pond Road, between Pond Avenue and the Jamaicaway. 9:00 AM to 10:30 AM.

I hope you can join me.

Good Birding!


PPS: What’s in the picture?

In my last post on the evolution of the Pipevine Swallowtail caterpillars I also included three images of a female Ruby-throated Hummingbird that I photographed on the same Harlequin Glorybower bush that harbored the Pipevine butterfly.  A keen 11 year old observer from Maine contacted me, kindness of her grandmother, to point out something in the images I had completely missed.  On the left side of the pictures the head, thorax and powerful front leg of a Praying Mantis are clearly visible:

The Praying Mantis and the Ruby-throated Hummingbird appear to be staring each other down.

This young naturalist took it one more step; she expressed worry that the hummer might fall prey to the preying Praying Mantis, and asked Grandma to query me on that issue.  As I read the email I mused that a child would be so naive as to think that a feisty hummingbird could possibly fall victim to a fierce, but much smaller, insect.  Then I read on; for backup she pointed me to a recent article in the New York Times:

I heartily recommend that all readers of this blog read this Science Times piece, not only for the raft of fascinating information about these critters, and the complete confirmation of my friend’s fears, but also to view spectacular photos of exotic mantid species worldwide.

Speaking of mantid pictures, this is the second time in a week that I have stumbled on, or been led to, a Praying Mantis in a photo I took when I hadn’t noticed it in the field:

With this photo I was documenting a Painted Lady Vanessa cardui butterfly, one of hundreds migrating through Boston right now, on a Butterfly Bush at the Boston Nature Center. Only when I got home and uploaded the image on my computer did I notice the Praying Mantis Mantis religiosa above.  Camouflage or inattention?

As to your concern, Grace, I can’t say for sure that the hummingbird survived to fly south sometime last week, but I do know it flew away from the predator while I was present.  And as the NYT article reports, predation of birds by Praying Mantises is pretty rare; they are prowling around in flowering bushes looking primarily for more reasonably sized fare- bees, wasps and probably butterflies!

Thank you for drawing all of this to my attention.

Butterfly postscript- and fall bird walks

In my last post I promised a followup on the Pipevine Swallowtail caterpillars that the Arboretum staff and I had collected and placed in inclosures back in late July. Here is a shot of some of them in their last stage, or instar;

Three 8th instar Pipevine caterpillars munching on Dutchman’s Pipe

I went away for a brief vacation and when I returned six days later, all three of my cats had pupated and formed complex chrysalides:

Dorsal view of one of the PV chrysalis attached to a vine stem.

The other two chrysalides, seen sideways, attached to the wall of the inclosure.

I had missed the transformation!  When I went to the Visitor’s Center at the Arboretum I discovered that they had about 12 chrysalides in their inclosure as well.  Now the question was whether these pupae would remain as chrysalides and “over-winter” before becoming butterflies (enclosuring), or if they would convert this fall, probably in September.

In mid August I went on another weeks vacation and while there I got a message from the Arb that two of their chrysalides had eclosed!  Upon my return I went immediately to my little cage and found a lovely Pipevine Swallowtail butterfly anxious to escape:

PV butterfly next to it’s empty chrysalis, left and an intact one on the right

Fifteen minutes later it was flying free in the Arboretum!

Over the next several weeks the “rare” Pipevine Swallowtail was being seen all over the grounds, as six of the Arb’s chrysalides had eclosed as well:

Pipevine Swallowtail on Harlequin Glorybower

We were not able to determine if any of them had mated and laid eggs.  There are still eight chrysalides that have not eclosed and we will try to successfully hold them over the winter in a variety of settings- outdoors and exposed, outdoors but covered and protected and indoors in an unheated environment- and await the coming of spring and hopefully another batch of butterflies for release.

On August 25 I had a swallowtail home run; all five species present in a grouping of the same flowering shrub, Harlequin Glorybower Clerodendrum trichotomum.  The Giant Swallowtail that has eluded me in Massachusetts finally appeared, just as the battery in my camera died!  I had to settle for a lousy shot of the lep on my old iPhone:

Giant Swallowtail Papilio cresphontes near Harlequin Glorybower Clerodendrum trichotomum

It has been a BIG butterfly summer!

But now it is time to turn our attention back to birds.  This beauty, captured on the same bushes with the butterflies, helped me make the switch:

Female Ruby-throated Hummingbird, in flight sequence

Female Ruby-throated Hummingbird, in flight sequence

Female Ruby-throated Hummingbird, in flight sequence

Unfortunately, hummingbirds are heading south right now so there won’t be any to be seen on my up-coming fall bird walks. But I’m hoping a few warblers or other late migrants might still be around.  Here are the dates:

Saturday 9/30 8AM starting from the Main Gate on the Arborway.

Saturday 10/14 8AM starting from the Peters Hill Gate on Bussey Street.

Check the Arboretum website for a map or to download a checklist.

Good birding!