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
Property owners have always affected, both in positive and negative ways, the health of the ecosystem that makes-up and surrounds their yards. About 85 percent of all invasive woody plants that are spreading through wild areas originally escaped from home gardens. Some nonnative invasive species do indeed provide birds with food but they also harm the surrounding ecosystem. Porcelainberry (or Amur Peppervine - Ampelopsis brevipedunculata) is a species on many of NETN’s park invasive species early detection lists because of the way it can take over woodlands and smother native plants. Many birds, unfortunately, devour the berries of these and other invasives unwittingly spreading these destructive plants far and wide.
Porcelainberries and other nonnative berries don’t pack the nutrient punch that native fruits do either. A study in Rochester, NY revealed the highest fat content and energy densities in fruits that migrant birds ate came from native shrubs. Another study compared two types of landscapes in southeastern Pennsylvania. One property in each of six pairs had a higher proportion of native plants and the other was more typical with an indigenous tree canopy that shaded lawns rimmed by alien ornamentals and ground covers predominately from Asia. Unsurprisingly, a greater diversity and abundance of birds and caterpillars were found in the yards containing naturally occurring plants. What did surprise researchers was just how dependent birds of conservation concern were on native-dominated yards. Wood thrushes, Eastern Towhees, Veeries, and Scarlet Tanagers were eight times more abundant and significantly more diverse on those parcels. You can find plants that are native to your area by going to: http://findnativeplants.com/.
Yes – there is an App for That
There are several fun and interesting citizen science projects and groups that can help to increase landowner understanding about the roles they play in an ecosystem and guide them to improving their own properties. One particular program that helps people out with this rewarding endeavor is the Cornell Labs Yardmap (http://content.yardmap.org/) project that lets landowners use satellite imagery of their properties to view and share habitat improvements that they and others have made and to get pointers on how to create better habitat in their yards. It’s also connected to eBird (a very popular online birding checklist program) so people can keep track of the birds they see on their properties as well.
Another program, called Hummingbirds at Home (http://www.hummingbirdsathome.org/), joins Audubon’s citizen science programs like the Christmas Bird Count and the Great Backyard Bird Count by enlisting people to log observations of hummingbirds on flowers and note blooming patterns. Several recent studies indicate that the arrival of hummingbirds on their foraging grounds is getting out of sync with food availability and flower pollination. The goal of the Hummingbirds at Home program is to help scientists better understand what’s going on, and to find ways everyday citizens can help.
Evidence continues to mount that any landowner can and indeed must play a role in preserving bird habitats. People wanting to make a difference need not completely tear up their entire lawns, as a measurable difference can be achieved almost immediately by planting even a single native plant, tree, or shrub in your yard. Many eco-mined landscapists recommend starting slowly and making a plan. There are many books available that give helpful advice on how to reduce your lawns with pointers on the kinds of plants, shrubs, and trees to plant for your part of the country and by habitat type.
With ever-increasing pressures on native birds, insects, and animals - property owners have become important players in the management of our nation’s wildlife. The actions of many individuals can make a big difference by enhancing biodiversity of native plants and animals of North America and the ecosystems that sustain them.