President's Corner | Sharyn Magee
Looking out the window at the grayness of winter, thoughts turn to spring and inevitability to birds and plants. Winter is a good time to take stock of the property and plan for the spring’s gardening. Intelligent gardening is applied ecology. Gardens play an increasingly important role in protecting our unsustainably declining biodiversity as too much habitat has been lost, fragmented, or degraded and increasingly our wildlife has no place to go. Even for obligate forest interior bird species, a well planted garden can be a welcomed migration stop. Birds need food, cover, and water. A well-planned garden can provide those needs.
If I want a healthy bird population on my land, I need a healthy diversity of native plants that attract a healthy diversity of native insects, not alien plants that produce toxins to which native insects have not adapted. I need to garden organically so I don’t poison the invertebrates that are part of a healthy ecosystem and provide essential protein for young birds of all species. I need to plan for a secession of berries from late spring to winter so there is food year-round for berry-eating species. I need plants that attract pollinators to ensure that my berrying shrubs produce well.
Native dogwoods, genus Cornus, are among our most valuable plants for birds. Eaten by ninety-eight species of birds, dogwood berries have a high lipid content that make them especially valuable for migrating birds. Migrating thrushes co-evolved with the Flowering Dogwood, Cornus florida. Unfortunately, because of problems with anthracnose disease, Flowering Dogwood has been too often replaced by Kousa Dogwood, which berries at the wrong time for migrating birds, if it berries at all. Ironically, Kousa Dogwood was probably the source of the anthracnose fungus. Not only do non-native plants provide sterile habitat, they too often introduce devastating fungal diseases and insect pests. Planting flowering dogwood in an area out of full sun in a more natural wooded setting helps mitigate the fungal problem. Other native dogwoods, especially the white berrying ones such as Gray Dogwood, Cornus racemose, are excellent wildlife plants.
Going native is easier said than done. The landscape and nursery industries are slow in understanding the need. When we replaced dead trees in an area that needed an evergreen buffer, we asked our landscape architect for native red cedar. He sent us a plan with a red cedar/ Chinese cedar hybrid, favored in the trade for its near perfect shape. We insisted on the native red cedar Juniperus virginiana. He replied “Oh, you want the one with the blue berries.” Yes, we want the one with the blue berries that help keep our bluebirds, waxwings, myrtle warblers, robins, and over fifty other bird species alive all winter. We want the one that is a functioning member of our ecosystem, not the one that is aesthetically pleasing but sterile. The non-native cultivar should not be more readily available and less expensive than the native plant. Consumers need to push the industry toward native.
Fortunately, there is a growing grassroots movement toward planting native, both in ecological restoration in preserves and on private property. The planting of pollinator meadows on school properties is especially heartening as it engages the younger generation. WCAS continues to support native planting through Holden Grants. We had a record number of requests for invasive species control and native plant replacement this year from grassroots groups that are improving wildlife habitat in their local preserves. If home owners will fill in the gaps between preserves by planting native, connecting corridors would form that would ultimately create a vibrant sustainable natural community.
This fall has been notable for the scarcity of birds. Baldpate Mountain, the Sourland Ecosystem Preserve, Cedar Ridge, St. Michaels’s, the Watershed Institute, and Mount Rose Preserve, the places I normally see good numbers of fall migrants, have been strangely quiet. The lack of warblers has been especially notable. One wonders where they have gone.
Along the eastern migration corridor, the traditional fall migration pattern for long distance migrants is that hatch year birds follow the coast and mature birds follow the mountains. Migration is partially innate and partially learned. Following the coast is innate. Birds that survive the first winter follow mature birds north along the mountain route, learning as they go.
It is possible that young birds have been pushed inland by the unsettled weather patterns this fall. Radar studies of migrating birds have shown birds being pushed into the central flyway this fall both before and during the atmospheric disturbances caused by Florence. Birds are very sensitive to atmospheric pressure and will alter course to avoid areas of low pressure. More normal flight patterns resumed after Florence. Unfortunately, radar gives no information on demographics.
Bird banding stations which study demography are essential for determining if the birds are changing route or if there was widespread nesting failure. Most fall migrants studied at Hannah Suthers’ Featherbed Lane Bird Banding Station in the Sourlands are hatch year birds, a pattern that has held for four decades. The majority of fall migrants studied at the Powder Mill Bird Banding Station in western Pennsylvania are adult birds. This fall the number of birds at Featherbed Lane is significantly down, but Powder Mill is reporting only a small decrease in the number of birds. While banding records show that the number of birds and number of species are showing long term declines, sharp short-term declines are especially worrisome since they may indicate widespread nesting failure.
This summer Featherbed Lane showed the lowest population recruitment in the history of the banding station. The summer of 2017 had the second lowest population recruitment. A wet late spring followed by a brutally hot summer may have been a factor in 2018. Hopefully, this extreme weather pattern is not the new normal. A study in California showed that resident birds were tracking global warming but that migrants were not, indicating that migrants will be especially hurt by climate change. The Featherbed Lane data supports this study, showing low numbers of hatch year Neotropical migrants, especially warblers and thrushes. In contrast, resident woodpeckers had a good breeding season. Juvenile pileated woodpeckers were the bright spot in an otherwise drab and depressive breeding season.
Habitat loss, degradation, and fragmentation continues to be the primary cause of bird decline both on the breeding and wintering grounds. Despite active measures to improve habitat at Featherbed Lane, habitat quality continues to decline, largely due to the opening of the canopy by dying ash trees and the subsequent invasion of Japanese stilt grass. Unfortunately, this scenario is playing out over the entire central New Jersey region as ash trees succumb to the Emerald Ash Borer, opening up the understory to non-native invasive plants. Birds that depend on the leaf litter for nesting and feeding are especially affected as the thick growth of the stilt grass denies the birds’ access to the leaf litter. Ovenbirds are declining where stilt grass is invading and are eliminated in areas of heavy growth.
The data shows that bird numbers are down this year and indicates that nesting failure was a factor in this decline. Bird banding station data is essential in documenting this decline. Since bird banding stations are few and far between, eBird data is essential in determining if the banding station data is local or reflects regional trends. While it is not as much fun to bird when birds are scarce, the data collected is essential to solve the puzzle of bird decline.
~ Sharyn Magee
The Musconetcong in Hunterdon County has been proposed for a gas-fired power plant. The Musconetcong, a C-1 stream, is considered by many anglers to be the best trout stream in New Jersey. The scenic Musconetcong Gorge, just below the proposed power plant location, is the heart of the Musconetcong Gorge Important Bird Area (IBA), which has breeding Louisiana Waterthrush, Worn-eating Warblers, Hooded Warblers, and Cerulean Warblers. The gorge is one of the seven IBA’s targeted by the proposed PennEast pipeline. The gas-fired power plant proposes to use water from the stream to cool the power plant, which would raise the temperature of the stream and make it less suitable for trout. It is hard to imagine a less suitable site for a power plant.
The PennEast pipeline also threatens Baldpate Mountain which has the highest density of nesting Neotropical migrants in New Jersey. In the 2017 breeding season, Washington Crossing Audubon citizen scientists added Canada and Cerulean Warblers to the list of breeding Neotropical warblers at Baldpate, for a total of fifteen species. In 2018, courting Barred Owls were documented at Baldpate. Baldpate Mountain is a jewel that should be left undisturbed.
Hopewell Township has proposed building high density housing on the Bristol Meyer fields adjacent to the Stony Brook. These fields are a critical corridor for linking the Pole Farm IBA, Rosedale Park, Curlis Lake, Baldwin Lake, and the Watersheds Institute. None of the preserves are large enough to support an eagle pair but when linked by the Stony Brook corridor, together they support a nesting pair of Bald Eagles.
These examples show a disregard for biodiversity in planning our infrastructures. New Jersey is a mostly built out state. Our remaining wildlands and waters are essential for protecting New Jersey’s unsustainably diminishing biodiversity. Yet developers, industrialists, and politicians continue to act as if there is no biodiversity crisis and one species can take all lands and waters for its short-term gain with no consequences. Meanwhile we continue to lose flora and fauna at an unsustainable rate.
Birds are indicators of a healthy biodiversity. If bird populations are declining, so are the populations of the native plants and insects upon which they depend. The State of North American Birds 2016 report states that thirty-seven percent of North American birds are at high risk of extinction and forty-nine percent are a moderate risk of extinction if no action is taken. Hannah Suthers has forty-one years of data from the Featherbed Lane banding station in the Sourlands that show central New Jersey is not exempt from this loss, as bird numbers have declined steadily at an unsustainable rate.
The loss of biodiversity is not limited to birds. The little brown bat population crashed in New Jersey last year. Emerald ash borer is decimating ash trees. Many reptile and amphibian species continue to decline from habitat loss, illegal collecting and automobile hits. Over abundant White-tail Deer continue to decimate the forest understory, driving many plant species to local extinction and destroying the habitat of creatures that need a healthy ground and shrub layer for survival.
To slow or reverse this loss, our ecologically sensitive lands need to be off limits to housing, retail developments and industrial infrastructure, pipelines and power plants alike. The effect of development on biodiversity should be a major consideration in all planning and zoning. Until it is, New Jersey will continue to lose biodiversity at an unsustainable rate and we will all be the poorer for it.
~ Sharyn Magee