Last Wednesday, our birding outings were held in the morning and evening. Susan Yurkus co-led at 9:30 am, and Linda Hunnewell co-led at our evening session at 6:30 pm. We began at 9:30 with an awkward tide level, 3.7 feet and falling in Newburyport, which is the beginning of the lower third of the tide cycle. This meant that when we arrived on the dike at Hellcat, there was still a smattering of Semipalmated Sandpipers and others on the flats in Bill Forward Pool, but most had skedaddled for better foraging as the tide exposed previously inundated flats.

Shorebirds in Migration
Shorebirds (and other migrants) make longer stops as they go south than they do on their northward migration. They linger at stopovers such as the Great Marsh as they build fat reserves for epically long flights to the Caribbean, tropical South America, and even the southern tip of Argentina, though only a few species go to the farthest extreme, species such as White-rumped Sandpipers and Red Knots. The “leisurely” notion of the southward migration is belied by the voracious foraging they engage in on these stopovers, and in the case of all the species that utilize tidal mudflats to find food, they are intimately tied to the tidal cycle. What drives the birds is the exposure or inundation of tidal flats that are rich in invertebrate prey. So predicting where tidal-flat-foraging species will be at any given time relates to the availability of the food resources in those tidal flats.

A Digression on Shorebirds and Tides
For finding shorebirds, predicting where they will be using an amount of time relative to a high or low tide of the day is a blunt instrument. The height of a mudflat relative to sea level and the extremity of the tides on a given day determines when and how long the flat will be available for foraging. In Newburyport, the actual levels of high and low tides on any given day vary through the month by almost 3 feet! The water level gauge on the Rt. 1 bridge in Newburyport is useful for predicting the exposure of Joppa Flats, one of the few tidal flats in our region to have a widely recognized name. The ideal tide level and action on Joppa Flats is at 1.0 feet on a rising tide, though a falling tide is good too at that level, as we observed last Wednesday.

At a water level of 1.0′ on the gauge, much of Joppa Flats is covered by water, but a band of exposed mudflat is visible near shore, making the birds on the flats easy to observe as the birds forage mostly on that exposed area. Tide levels are measured from “zero” at the height of the mean low tide, which is regarded as “sea level.” All we can see on a tide chart, however, is the predicted level, which can be greatly altered by the flow rate of the river, by wind, by variation in ocean currents, and by barometric pressure. I nevertheless am finding that 1.0′ predicted tide level in Newburyport is useful for planning birding outings to Joppa Flats, but that is only because of smartphone apps such as “Tide Chart – Free,” which give you the time of day that the gauge in Newburyport is predicted to read 1.0′. Tides also affect the movement and foraging of gulls, so there are probably perfect gull moments that could be predicted by the tide height as well. The perfect gull observation tide height could be the next project, though it took a few years of observations to feel confident of what I have shared here…

Back to Birding
We enjoyed the scene at Hellcat for a while, but the flats emptied about 30 minutes after we arrived, so after standing around watching the shorebirds leaving, and getting some looks at a Merlin, maybe a Peregrine Falcon, and some Ospreys, we moved on to North Pool Overlook.

The ducks in North Pool should have been categorized as “Large Grayish-brown Ducks,” and “Small Grayish-brown Ducks,” the only two types of ducks one finds at this time of year as they linger in their “eclipse plumage.” We did our best to distinguish them according to accepted taxonomy, however, and enjoyed seeing the first decent number of Green-winged Teal (“Small Grayish-brown Duck” adults – “Small Grayish-brown Duck” juveniles were young Gadwalls, distinguished by the color of the speculum, a section of secondary flight feathers). While this is a birding post, we love all earth’s critters, so were delighted when a coyote trotted by, totally unconcerned by our observation from a good distance.

With not much time left, I decided to offer everyone either an early lunch or some extended birding time at the Joppa Park boat ramp. When we arrived there, the flats were fixin’ to open, and the name of the game was dancing gulls. Bonaparte’s Gulls have a dancing way of flying above the water and dropping for prey at the edges of submerged flats, and we got a nice view of that action as the flats emerged. “Boneys” also are dainty in the way they sit on the water, but as we looked at them, one stood out as larger and with a different-looking “hood” – a Black-headed Gull!! The back of the bird’s hood ended even higher on the nape than it does on a Bonaparte’s, and the color was obviously brownish, not black, even though it was molting to the winter-white around the face. The bird’s bill color was also easy to see, not all dark like a Bonaparte’s Gull, but reddish-orange at the base. We spent a long time observing that bird, and enjoying the arrival of the shorebirds promised by the opening of the flats. Finally (!), our own rare bird for WMB that I had been writing about here in the absence thereof. What will be next?!

Our evening outing should be recorded here, as our “itinerary” is one that I can still recommend at this point in the season. Linda and I met birders at Perkins Playground in Newburyport, where a wonderful egret spectacle takes place every evening behind the ball field. About 400 Great and Snowy Egrets arrive there by dark, and the finale of the last third of the roost arriving in a concentrated period is a thrilling show. Night-Herons of both species cavort about as they get their engines revving for the nighttime feeding frenzy. As darkness arrives, they “bark” more and more, and as the egrets become ever more crowded, their prehistoric-sounding squawks and growls fill the air while they tussle for position, sounds that belie their usual elegance during the awkward period in which they find purchase on the branches of the trees.

But we didn’t stay for that finale, as we wanted to see the final flight of the day for Tree Swallows in the reeds of North Pool at Parker River NWR. We ran out there and had a very nice show of that odd final flight, when swallows roosting in the tops of the reeds inexplicably lift up in a swirling cloud, make dramatic dashes and rotating vortices, and then drop like stones back into the reeds for the night. This was happening as recently as last night, Sunday August 30, so I recommend you shut off your screen and get to one of those spots to see the best show on the North Shore. But which one you end the day with is up to you to decide, as you can’t be in both places at once!

Our List (9:30 am session only. Key: 100/150 = 100 on Plum Island, 150 at Joppa Flats):
Canada Goose (10) – various on Plum Island (PI).
Gadwall (8) – North Pool Overlook (NPO).
Mallard (35/25) – various on PI.
American Black Duck (2) – NPO.
Green-winged Teal (12) – NPO.
Wild Turkey (2) – roadside, PI.
Rock Pigeon (9) – various.
Black-bellied Plover (100) – Joppa Flats (JF).
Killdeer (1) – Bill Forward Pool (BFP).
Semipalmated Plover (200/150)
Least Sandpiper (1) – BFP.
Semipalmated Sandpiper (25/150) – BFP on PI.
Short-billed Dowitcher (17/10)
Lesser Yellowlegs (4/10) – BFP on PI.
Greater Yellowlegs (35/15) – various on PI.
Bonaparte’s Gull (60) – JF.
Black-headed Gull (1) – JF.
Ring-billed Gull (35) – various.
Herring Gull (20/100) – various on PI.
Great Black-backed Gull (5) – JF.
Common Tern (1) – JF.
Double-crested Cormorant (5/15)
Great Blue Heron (2) – salt marsh from Hellcat dike.
Great Egret (25) – various on PI.
Snowy Egret (10) – various on PI.
Osprey (4/1) – from Hellcat dike on PI.
Bald Eagle (1) – JF.
Merlin (1) – over the Bill Forward Pool dike.
Peregrine Falcon (1) – same as above.
Eastern Kingbird (1) – roadside on PI.
Tree Swallow (20K+) – On Parker River National Wildlife Refuge, all spread out above thickets and dunes from parking lot #1 to the S-curves.
Barn Swallow (4) – mixed with above.
American Robin (5) – various on PI.
Gray Catbird (2) – roadside on PI.
European Starling (35) – roadside on PI.
House Sparrow (5) – along Sunset Drive on PI.
American Goldfinch (8) – various on PI.
Song Sparrow (4) – various on PI.

During our two sessions of Wednesday Morning Birding last week, one at 7:30 am and the other at 9:30 am, we moved about according to the dictates of the tide. With the early low tide expected to reveal all sorts of avian goodies on Joppa Flats, for our first session with Dave Weaver we met at the Joppa Park boat ramp, which has been recently renovated by the city. We spent a leisurely time observing gulls, shorebirds, Common Terns, and a few Bald Eagles as the tide pushed birds closer and closer to shore. What a treat when we have the timing right! I was careful to count the many egrets (and one Glossy Ibis!) near the wastewater treatment plant to get a good ratio of Great to Snowy Egrets, 42 vs 14. I did a similar survey of Greater to Lesser Yellowlegs, 91-18. We are wishing we could find a godwit out there – it’s one shorebird that’s easy to pick out when the birds are far down the flats!

Having wrung every identification opportunity out of the flats, we headed for Plum Island, hoping the American Avocet from the day before would be in the Main Panne. Alas, no avocet. The Main Panne was transformed since the previous evening, when there had been an extensive mud flat fringe around the edge of the panne. The high tides had been getting higher each day as they do through the monthly cycles, and had reached 8.8 feet in Newburyport. That was enough to fill the Main Panne, temporarily obscuring a lot of roosting and foraging habitat, and perhaps making it less attractive to an avocet.

We went on to Hellcat, where one of the Least Bitterns that’s been regularly seen there was again visible. The week before we had seen about ten thousand Tree Swallows at Hellcat, but this week there were few in evidence there. The numbers and locations of large flocks of Tree Swallows shifts about in time and location. Although we didn’t see too many in our early session at Hellcat, as our first group of participants departed and I went on to meet the next one at the Main Panne, we found a huge congregation at the Main Panne that had not been there earlier.

The numbers of shorebirds at Bill Forward Pool were not very great during the early session, but they did build as the morning wore on. By the time the second session of Wednesday Morning Birding was drawing to a close, the high tide roost congregation was significant. One particular treat for us was spotting a Northern Harrier flying by over the marsh. Other birders have started to report harriers recently, but that moment of seeing a bird that represents a new season is special when it happens “live.”

The 9:30 group kicked off at the Main Panne, then moved on to North Pool Overlook, where a couple of night-herons were visible as they roosted, and where one lone Glossy Ibis (perhaps the one we’d see earlier?) was foraging and preening. There are lots of Mallards around right now, with some very small ones and others that were hatched early enough to be full grown swelling the ranks. Ducks are mostly in “eclipse” plumage now, which is rather dull to look at compared to the finery the drakes will be showing by fall.

We have two reliable bird spectacles in our area during these weeks of late summer: a big egret roost at Perkins Park in Newburyport, and the evening flights of Tree Swallows in the reeds at North Pool on the Refuge. Rare shorebirds and waders keep popping up, not to mention a Crested Caracara that visited Woodsom Farm in Amesbury for a few days early this week, so Wednesday Morning Birding is bound to have one uncommon species show up during our gatherings soon, right? We hope we will see you for one of those!

Our list:
Legend: (7:30 am session – x/y = mainland/island, 9:30 am session)
Canada Goose (3, 1)
Gadwall (0, 2)
Mallard (35/30, 30)
American Black Duck (0, 2)
Green-winged Teal (0, 2)
Wild Turkey (2, 2)
Mourning Dove (5, 0)
Black-bellied Plover (50/25, 150)
Killdeer (2, 1)
Semipalmated Plover (100’s/40, 400)
Least Sandpiper (3, 2)
White-rumped Sandpiper (1, 0)
Semipalmated Sandpiper (1500+/50, 750)
Short-billed Dowitcher (5, 2)
Spotted Sandpiper (1, 1)
Lesser Yellowlegs (18/5, 3)
Willet (1, 0)
Greater Yellowlegs (91/25, 35)
Bonaparte’s Gull (72, 0)
Ring-billed Gull (15, 0)
Herring Gull (200/15, 12)
Common Tern (25, 0)
Double-crested Cormorant (10/, 6)
Least Bittern (1, 1)
Great Blue Heron (3, 1)
Great Egret (42/12, 7)
Snowy Egret (14, 0)
Black-crowned Night-Heron (0, 2)
Glossy Ibis (1, 1)
Osprey (1/2, 3)
Northern Harrier (0, 1)
Bald Eagle (3, 1)
Eastern Kingbird (4, 4)
American Crow (1, 0)
Tree Swallow (2000, 7000)
Barn Swallow (7, 0)
Black-capped Chickadee (2, 0)
Red-breasted Nuthatch (1, 0)
American Robin (0, 50
Gray Catbird (3, 2)
Northern Mockingbird (0, 2)
European Starling (3, 15)
Cedar Waxwing (2, 2)
House Sparrow (15, 0)
American Goldfinch (4, 5)
Song Sparrow (4, 5)
Eastern Towhee (2, 1)
Common Grackle (2, 0)
Yellow Warbler (1, 0)
Northern Cardinal (2, 0)

Wednesday Morning Birding this week was a bit slow, so thank goodness for two facts: 1. Least Bitterns are still being easily observed from the dike at Hellcat.
2. One never tires of watching Least Bitterns skulk around, appearing and disappearing in the reeds. Sometimes a Least Bittern’s ability to suddenly blend into invisibility truly gives the impression of a “magic trick.” Why are they so much more apt to do that than say, a Green Heron? The difference is in subtleties of movement, postures and pattern, and maybe something else, some je ne sais quoi. But we enjoyed that literally elusive quality, and we can do so again and again. Have you rewatched episodes of Seinfeld, gone again to hear a favorite musical performance, gazed at your children – again? Watching Least Bitterns bears such repetition.

We had a similar but distinct experience with the Tree Swallows. At times the swirling horde we saw Wednesday came and went from the Phragmites stand in North Pool to the pines and deciduous glades near the Hellcat Parking lot and Bill Forward Blind. At the peak of the show, we saw about ten thousand birds circling the pines near us, and clots of them delighted us closer by. When we see this spectacle, something happens to your brain. Medical-ish websites list activities that produce endorphins, a class of chemicals that we produce/store in our pituitary gland and other sites. Endorphins block pain and produce euphoria. Those websites should include repeated observation of hundreds but especially thousands of Tree Swallows in their list of endorphin boosting activities. Sometimes just remembering that sight will do the trick.

Our outing this week happened when the Plum Island South tide level was at 3.3 feet and dropping. That is where the lowest third of the tidal range begins, so the shorebirds were steadily disappearing from the flats around the Main Panne and Bill Forward Pool, which are high tide roosts for migrants. I would really like to know what the surface area of high tide roosts is over the Great Marsh, and how those areas vary in foraging potential. Anybody need a PhD topic? The south end of Bill Forward Pool has been an area for both roosting and foraging for may years, because of the active management led by Nancy Pau, biologist for Parker River National Wildlife Refuge. Thanks, Nancy!!

We scanned the far flats for birds other than the common “substrate species” of Semipalmated Plovers and Semipalmated Sandpipers, Black Bellied Plovers, Short-billed Dowitchers, and both species of yellowlegs. This week the less common birds we saw and identified as a group were three Least Sandpipers, and one White-rumped Sandpiper. That is the typical mix, however, so our quest for more excitement awaits a better tide, closer views, and the diversity of species that seems to increase as the season progresses to add any truly uncommon or rare species. Where is this year’s American Avocet? On Plum Island so far in this southward migration season, there have been some Stilt Sandpipers, a Baird’s at one point, a few Whimbrels, and others that I may be leaving out, but our Wednesday Morning Birders have not been there for the real rarities …yet. More to come!

Our list:
Note: all birds recorded were seen from Hellcat dike in/near Bill Forward Pool unless otherwise noted.
Mallard (45)
Wild Turkey (2) along road between Hellcat Observation Area and Main Panne.
Mourning Dove (2) – along road between Hellcat Observation Area and Main Panne.
Black-bellied Plover (15)
Semipalmated Plover (250)
Least Sandpiper (3) – North Pool
White-rumped Sandpiper (1)
Semipalmated Sandpiper (~400)
Short-billed Dowitcher (3)
Undetermined Yellowlegs spp. (30)
Lesser Yellowlegs (1)
Greater Yellowlegs (20) – both pools.
Herring Gull (12) – various.
Least Tern (3)
Double-crested Cormorant (2) – flyovers.
Least Bittern (1-2) – North Pool.
Great Blue Heron (1) – North Pool.
Great Egret (3) – various.
Osprey (1) – marsh west of Main Panne.
Red-shouldered Hawk (1) – flyover while gathering in Hellcat parking lot.
Eastern Kingbird (5) – birding by ear (or visual) along the road (bbeatr).
Red-eyed Vireo (1) – bbeatr
Tree Swallow (10K+)
American Robin (1) – bbeatr
Gray Catbird (3) – bbeatr
Northern Mockingbird (1) – bbeatr
European Starling (25) – various
Cedar Waxwing (3) – bbeatr
American Goldfinch (2) – bbeatr
Song Sparrow (3) – various.