Among the many reasons NETN monitors landbird populations is that they are an important component of a park’s natural resource community and can be sensitive to sudden or rapid ecosystem changes. On the other side of the coin, they can also be indicators of healthy and diverse ecosystems. Management activities aimed at preserving and enhancing habitat for migratory birds can have the added benefit of preserving entire ecosystems and their associated ecosystem services (CO2 sinks, erosion control, oxygen providers, run-off control, etc). Most national parks are limited as to what they can do with regards to direct forest management, but one of NETN’s member parks - Marsh-Billings-Rockefeller NHP in central Vermont has a little more leeway with regards to how its forests are managed. Home to one of the oldest continually managed forests in the country, the park was founded with a mandate to continue the history of hands-on forest management of its roughly 550 acre forest.
Like many forests in the northeast, the park’s woodlands are relatively young and lack much of the complex and dynamic features that would be found in typical forests of much greater age. Using data provided by two of NETN’s long-term monitoring programs (forest health and breeding landbirds) the park is taking direct action in managing the forest to improve overall ecosystem function, encourage healthy tree stands, and enhance bird habitat availability.
Build a Better Backyard
You don’t need to be a national park manager, however, to help improve bird and wildlife habitat. In point of fact many scientists are concerned our natural areas — parks, preserves, and national parks — aren’t enough to sustainably support natural ecosystems long-term. Every landowner has the opportunity to contribute to a healthier and more complete ecosystem by making changes to the ways they take care of their properties - whether they be several hundred acres or several hundred square feet. For larger landowners engaged in forest management, several Audubon groups in the northeast including Vermont Audubon and Mass Audubon work with area foresters to help landowners integrate the practice of timber management with songbird habitat improvement. Landowners with relatively small pieces of land can also create better bird habitat in their yards. Studies have shown that even small habitat improvements to your yard can have a meaningful impact on wildlife.
Birds, butterflies, and other insects help control pests and seed and pollinate the food we eat - but human actions have seriously impacted their numbers. According to the National Audubon Society, the 20 birds on the Common Birds in Decline list have lost at least half of their populations in the past 40 years due to residential and industrial development. Monarch Watch estimates that 6,000 acres of monarch/pollinator habitat a day are lost in the U.S. to development (2.2 million acres per year) totaling about 147 million acres since the program began in 1992. That’s an area 4 times the size of Illinois. As development pressures continue to increase along bird migration corridors and impinge upon pollinator and wildlife habitat, scientists, conservation groups, and gardening clubs are encouraging people to forsake much of their relatively lifeless lawns and to cultivate native shrubs and plants that have many benefits to the landowner and the environment alike.
Lawns are anything but green
Ironically, maintaining a meticulous, weed-less lawn is one of the least “green” things you can do in your yard. Reducing the size of manicured lawns means less water needed to irrigate it as well as less equipment and fossil fuels (gas and oil for mowers, weed-whackers, and leaf blowers; fertilizers, pesticides, seed spreaders, lawn aerators, sprinklers, hoses, etc.) needed to maintain it. A Yale University study estimated that the U.S. uses more than 600 million gallons of gas to mow and trim lawns each year. The amount of natural gas required to make approximately 200 bags of lawn fertilizer would heat your home for a year. Each 40-pound bag contains the fossil fuel equivalent of about 2.5-3 gallons of gasoline. Transporting these bags of fertilizer from the factory to the store and to your home requires additional fuel.
In the U.S. over 45 million acres—more than 950 times the size of Acadia National Park—are carpeted with lawns, and about 500 square miles of turf grass are added every year. Lawn maintenance can be a huge undertaking of both time and money as the average U.S. homeowner spends about 40 hours a year mowing grass and collectively spends over $40 billion on lawn care. The U.S. Environmental Protection Agency estimates that 80 million households spread about 90 million pounds of herbicides and pesticides on lawns in a year (more than 10X than is used for farming), which can seep or be washed into local aquifers, ponds and streams impacting human health and damaging wildlife food sources. Lawns are also water intensive. According to The Handbook of Water Use and Conservation, roughly 2 trillion gallons of water are used on lawns annually - half of which isn’t even taken up by the grass as it is evaporated or runs-off due to over-watering.
Replacing some lawn with a variety of native plants, shrubs, and trees of differing size classes is a great way to increase the health and utility of your property to native birds, insects, and wildlife. When you take a tour of your yard and look at the leaves of some of the nonnative ornamentals there, you’ll likely notice they show little to no signs of insects feeding on them. This is in contrast to the neighboring indigenous maples, oaks, cherries, willows, etc. While this may be a bit more aesthetically pleasing, if these are all your yard has to offer it can be a virtual food desert for native birds - birds that have often flown thousands of miles to feast on what once was an incredible bounty of insects that lived in relative balance with native plants. Healthy bird communities coincide directly with healthy insect populations. More than 9 out of every 10 terrestrial North American birds raise their young on insects, mostly caterpillars which are rich in fats and proteins.
As one example, the Carolina Chickadee requires a stunning 390 to 570 caterpillars per day to feed its clutch of 4 to 6 chicks in the 16 day time-span from when they hatch to when they fledge. This totals about 9,000 caterpillars just to raise one batch of Chickadees. And almost all the foraging for those caterpillars happens within 50 meters of the nest, demonstrating why having a lot of caterpillars in your yard would benefit these and many other birds. And it’s not just birds that need insect biomass, many species of spiders, frogs, toads, bats, rodents, foxes and even bears all need insects and the larval host plants that support them to survive.
If you enjoy trees and are looking to get the biggest ‘bang for the buck’ to help your local birds and wildlife, keep or plant more oak trees, which lead the list of top 20 tree species that support the most caterpillars (534 species of the wrigglers). Cherries and willows are also highly valuable for birds and wildlife. Selecting plants that host the insects birds eat is only one piece of a healthy bird habitat mosaic however. Plants that provide fruits and seeds give birds much needed energy during migration, making them equally essential. Plants that provide shelter during extreme weather, nesting structure, and safety from predators are also ideal.
When in Doubt – Go Native
Yes – there is an App for That
Last updated: November 20, 2018