By Sandra Keller

Bivalve is comprised of 4,200 acres of forested uplands, brushy edges, fallow and crop fields, brackish wetlands and a small freshwater pond. Good views of the Maurice River near the Delaware Bay, and an active clam processing plant, add to the great birding opportunities here. Bivalve is located a bit off the regular birding route and so may not very well known to many Delaware Valley birders. Officially known as the Commercial Township wetlands restoration area, Bivalve is located in Port Norris, Cumberland County, New Jersey with access points off of Route 553. PSE&G owns and manages the site for marsh grass as part of their Estuary Enhancement Program that is creating areas for fish hatcheries as a result of mitigation against the fish kill at their Salem County nuclear generating plant. The tidal marsh grass areas are constantly changing, with more and more grass starting to grow and less areas for roosting shorebirds at high tide. Some of the fields have “grown-up” to successional brushy edges. This is better for some species, worse for others. I don’t know if plans are in the works for intensive mowing. With all of the varied habitats, my cumulative species list is now up to 239 for the seven years that I have been keeping a Bivalve list.

Timing:
The mudflats are tidal so this has to be kept in mind when birding here for shorebirds and waterfowl. Predicting the proper tides can be a real challenge, especially since wind direction and intensity also impact water levels. Basically, I have found that a half hour to an hour after low tide is best at Bivalve. That is actually when the water starts to drain from the mudflats and conditions should be good for most shorebird species. High water levels are needed in winter for waterfowl. Visit the National Oceanic and Atmospheric Administration’s Tides On-Line webpage for current information at http://tidesonline.nos.noaa.gov/. Passerines are usually best in the morning, but can also be good in the afternoon with a bit of diligent searching. The gulls along High Street near the clam processing plant feed all day, so this area can be checked at any time.

Photographic Opportunities:
Photo ops are excellent at Bivalve. The shorebirds are right alongside the boardwalks on most tides and the birds don’t usually flush as you walk around. If they do flush, they return quickly. The herons, egrets, and ducks can be a bit harder to get close to. Expect a different species mix depending on water levels. The gulls feeding on the clamshells along High Street are extremely close. I have gotten almost full-frame shots with my small Nikon Coolpix using my car as a blind. Passerine photography can also be good since sparrows sometimes feed right along the Strawberry Avenue trails. If you are interested in doing passerine photography, I recommend that you find the current feeding area, set up your equipment and then wait for the birds to come to you.

References:
Bivalve is briefly mentioned in Bill Boyle’s “A Guide to Bird Finding in New Jersey”, published by Rutgers University Press, 2002. The area is given more coverage in Clay Sutton’s “Birding Cumberland: a Birder’s Guide to Cumberland County, New Jersey”, published by Cumberland County in 2003 and available at Cape May Bird Observatory’s two centers in Cape May County.

Directions:
Bivalve is located just south of the town of Port Norris and on the west side of the Maurice River. I haven’t managed to explore all of the trails and viewing areas, and still have not walked the whole dike system. Some of the tidal areas are best explored from a canoe. Many fields around the access roads are private property but birding from the road can be quite productive.

The three areas mentioned most in the seasonal accounts are shown below. Check the New Jersey Delorme Atlas, page 66, grid J10 for more information:

High Street:
? Turn onto High Street from Route 553. The first viewing platform is 8/10 of a mile down the road. Look for a bike route sign along the road that indicates a right turn. This is where to go for the boardwalk and dike access to the first viewing area.
? Proceed another 5/10 of a mile down the road for the second High Street viewing area. En route you will pass the clamshell pile. Stop here to look at the gulls as they feed on the pile and roost on the pilings near the factory. This area is not for the faint of heart (or smell!) and I don’t recommend it to those who can’t take the smell of rotting clams. Continue down and park at the concrete building for another dike access then continue further along the sand road (which can be impassable in the winter for non four-wheel drive vehicles) to an excellent overlook of the Maurice River and Heislerville WMA on the far bank. An observation tower here is accessible from the dike.
Strawberry Lane
? Return to Route 553 and go 5/10 of a mile north from High Street Turn left and proceed down the road. It is very poorly maintained at the end near the parking area. The boardwalk is straight ahead from the parking area while the trails start off to the east.
Robbinstown
? Return to Route 553 and go another 8/10 of a mile north along Route 553 from Strawberry Lane. Turn left and continue down the road for 5/10 of a mile to an opening on the left which gives another view of the mudflats. A freshwater pond is on the right.

Getting Started:
The area is so diverse that most birders will want to explore on their own after getting to know the place. Who knows what waits to be discovered? Maybe there are breeding Black-necked Stilts, Avocets, and Mississippi Kites just waiting to be discovered down here in Cumberland County. Deer ticks and chiggers can be a major problem in Cumberland County so be prepared. I like to wait for the first frost in the fall to go off-trail.

Fall:
The species variety is greatest in this season and it is my personal favorite. Fall starts in mid-July with migrating shorebirds. Expect both species of Yellowlegs, Western, Semipalmated, Least, and White-rumped Sandpipers. With careful scrutiny, the Short-billed Dowitcher flocks should yield the occasional Long-billed Dowitcher. Black-bellied and Semipalmated Plovers, Dunlin, Ruddy Turnstones, Stilt Sandpipers, Willets, Solitary and Spotted Sandpipers can all be found feeding on the mudflats in the fall. Both Marbled and Hudsonian Godwits are annual, but rare. I like to start on Robbinstown Rd on an outgoing tide when the water is receding but still covers the mudflats. I typically scan first for the bigger shorebirds like the Godwits. Then, after a half hour or so, the water has receded enough and conditions are right for the small and medium sized shorebirds. I head over to Strawberry Lane for the peeps and usually stay there until the mudflats are completely exposed.

Cold fronts in August bring the first southbound passerines. East Point, just across the Maurice River, is a known migrant trap and good fallout there often results in migrants at Bivalve. The trees and edges along Strawberry Lane can be productive after a fall cold front. Keep an eye out for migrating hawks. The buteos are flying fly mostly in the late morning and early afternoon, the accipiters all day, and the falcons in the afternoon. The dikes along High Street provide a good vantage point for watching the skies. Listen for Bobolinks overhead as they migrate south and feed in fields of Fox Tail Grass. Dickcissel is another bird mainly heard only as they fly overhead to their feeding areas. October is sparrow month. The paths along Strawberry Lane and the dikes along High Street are my favorite areas to explore for these seedeaters. Keep an eye out for Clay-colored, Lincoln’s, and Lark Sparrows. The dabbling ducks are back in October and raptors are still migrating, so keep watching the skies. November brings the diving ducks and is the best time to search for Orange-crowned Warbler. Try the weedy fields along Strawberry Lane for this species. I can’t even begin to list all the species to be expected at this season. Keep an eye out for rarities like Cave Swallow, Western and Ash-throated Flycatchers and Swainson’s Hawks. In a nutshell, expect anything!

Winter:
December is a transitional month. The birds are still moving, but the weather will play a key role in what’s around now. Assuming the water is not completely frozen, Strawberry Lane and High Street provide good viewing areas for scanning the tidal marshes for Green-winged Teal, Northern Pintail, American Widgeon, Gadwall, Black Duck, Mallard, and all three species of merganser. Keep an eye to the skies as Bivalve is excellent area for wintering raptors. Bald and Golden Eagles, Harrier, Black and Turkey Vultures, Red-tailed Hawk, Merlin, Peregrine, and Rough-legged Hawks can all be expected here. Snow Geese are usually on the move to and from their feeding areas. Dawn and dusk can be the best time to view the birds as massive numbers of them return to their roosting areas. Watch for Short-eared Owls at dusk from either viewing area and listen for Great Horned Owls calling from the woods. This time of year is also good for scanning the Maurice River from areas along High Street for the diving ducks like Canvasback, Common Goldeneye, Lesser Scaup, Bufflehead, and Long-tailed Duck. Watch here also for Horned Grebe and Red-throated Loon. Gulls – Lesser Black-backed, Herring, Bonaparte’s, Greater Black-backed, Ring-billed, and Iceland - are all regular here in winter. The best areas to check are High Street at the clam processing plant and along the river. The trails that meander through the fields and woodland edges along Strawberry Lane are excellent this time of year for Field, Chipping, Tree, White-throated, White-crowned, Fox, Song, Swamp, and Savannah Sparrows. Orange-crowned Warbler is also found along here. A new path has been put in on the left of High Street as you are driving out – before the first boardwalk access. It passes a wet grassy area and continues down toward a bridge over a small creek. I have had Eastern Meadowlark, Savannah Sparrows, and Least Bitterns here. Birding possibilities along this new path will depend on how dry or wet the area is. Annual rarities to check for in winter include “Eurasian” Green-winged Teal, Eurasian Widgeon, Barrow’s Goldeneye, Eared Grebe, Glaucous and Black-headed Gulls, Vesper and Clay-colored Sparrows plus whatever else shows up. Both shrikes have been seen in Cumberland County so look for these birds at Bivalve. Watch for lingering birds in mild winters. I had an Osprey in the area on January 8, 2004.

Spring:
This is the season for song and beautiful breeding colors. It’s when I see my first Ospreys back on the nesting platforms throughout the marsh. The number of dabbling ducks increases, swallows and martins return, herons and egrets start feeding here again later on in spring. Both the High Street and Strawberry Lane boardwalks are excellent vantage points from which to scan the marsh at this time of year. Woodcock use the surrounding fields for their display flights come the warmer nights starting in early March. Robbinstown Road and its access points should be checked in April and May for Virginia, Clapper, and the rare but annual migrant King Rail. The dike at the end of Robbinstown Road can be good for these species but beware of ticks. I had a King Rail right at the start of the dike here this past spring. All six New Jersey breeding terns can be found here; from the ever present Forster’s Tern to the much more rare Royal Tern. By late spring you can expect migrant warbler songs in the woods along Strawberry Lane but keep in mind that south Jersey is not a predictable spring migrant warbler area. The proper conditions are needed; namely a couple days of south winds to get the migrants moving north, then a cold front to hit at night to put the birds down. Even with poor migrant conditions, a few migrants should be in the trees along Strawberry Lane. Early morning is best.

Shorebirds will have started their flight north and will stop over here to rest and feed. Tidal conditions are the key to good viewing in the spring just as they are in the fall. Keep an ear out for Bobolinks. Their distinctive “bink” flight call can usually be heard around the fields come May. Bobwhite were regular along Strawberry Lane and Robbinstown Road but have declined recently. Although they are not a “given” anymore, I still hear them now and then. May is the time to search for Cliff Swallow in the swallow flocks. It is an annual migrant that will take searching to find. A night’s foray should produce both Chuck-will’s-widows and Whip-poor-wills along Strawberry Lane and Robbinstown Road in the proper habitat. Some regular rarities to watch for are Ruff and White-faced Ibis in mid-April and Wilson’s Phalarope and Black Tern in May. I have had Sedge Wren in May twice along the dikes off of High Street. Try the fields around Robbinstown Road and Strawberry Lane for Mississippi Kites. They are seen annually in the area.

Summer:
Although summer is probably the slowest time at Bivalve, a summer birding trip can be rewarding. Yellow-breasted Chat and Blue Grosbeak are regular breeders along Strawberry Lane, and June is be a good time to go see them. Ospreys nest on the numerous platforms at Bivalve and it is enjoyable to watch the young grow and fledge. Herons and egrets are always around in some numbers. Least Bitterns nest in the freshwater areas and are fairly numerous some years depending on water levels. Try the pond at the second observation area along High Street near the concrete building. Brown Pelicans use Bivalve at high tide for roosting in the summer months and they can be numerous in some years. I had eighty birds roosting in the area one day in 2002. In other years, I have seen only a few. Try walking the dike system or even exploring some of the more inaccessible areas by canoe or kayak in summer. Who knows what could show up?

A full day of birding can easily be spent at Bivalve. It is one of my favorite areas in New Jersey and I hope I have conveyed to everyone the possibilities here. Good birding and please email me your trip reports!