Monday, October 29, 2012

Rooting for the underdog: eastern bluebirds

Imagine you live inside of a tree.  Your hunger forces you down to the ground where you glean ants and worms out of the grass.  Upon returning to your tree you find a strange bird comfortably occupying your home.  Its time to move. 

An eastern bluebird in its preferred open-woodland habitat

This has happened again and again to the eastern bluebird, which live in small holes in trees.  The non native European starling and house sparrow (both intoduced to the Americas after the Columbian exchange) pose a serious threat to the bluebirds: starlings (another 'cavity-nesting' bird) enter bluebird cavities and evict the occupants while house sparrows kill bluebirds and/or destroy bluebird eggs.  Its a rough world for the adorable bluebird, which are also negatively affected by severe winters and loss of habitat. 

The bluebird has been subject to an extremely dynamic and turbulent history in North America. See here for a nice synthesis of their history.  To sum it up, due to loss of habitat, land conversion, and the introduction of non native birds (European starling and house sparrow), the bluebird population crashed around the middle of the 20th century.  Their numbers were so low that by the 1960's birders and scientists feared that bluebirds may actually become extinct.  A widespread, grass-roots movement to save the bluebird ignited a new interest in their plight, research for their conservation and the spread of bluebird boxes across the country.       

Bluebird boxes?  Yes, there is something that you can do to help the bluebird! 

To mimic the tree cavities that bluebirds find so comfortable, scientists, conservationists, nature enthusiasts, birders and school children have built and errected small wooden homes for the bluebirds, A.K.A., bluebird boxes.  These easy to build boxes provide bluebirds with a safe place to make a nest and bring up their babies. European starlings are too big to fit through the door hole which means that the bluebird family is safe from unwanted squatters and killers.        

A bluebird on a bluebird box.  A bluebird's door hole must be precisely sized (1.5 inch) to allow bluebirds to enter while keeping out unwanted European starlings.   

This type of human mitigation has truly paid off; bluebird populations have responded to the wide-spread use of bluebird boxes.  Their numbers are up, but still not as high as they were before humans severely impacted them with starlings, sparrows and sprawl.  Choosing to erect a bluebird house is still a fun and worthwhile endevour - one that directly helps wild animals survive in the face of serious human-induced obstacles.  You can see working bluebird boxes in the meadows at the Pound Ridge Land Conservancy's Clark Preserve and the Westchester County's Ward-Pound Ridge Reservation

If you want to build or buy a bluebird box you should consult the many websites dedicated to bluebirds to understand their specific habitat and ecological requirements.  Here are a few websites:

Bluebirds forever
From the USDA
Bluebird box info and building plans

A bluebird sitting on a bluebird box.  This picture shows how a bluebird box can be mounted onto a piece of metal. 

Friday, October 12, 2012

Out with the lawn, in with the meadow

In last week's blog post I reported that the Pound Ridge Land Conservancy recently oversaw the mowing of their five-acre meadow on the Clark Preserve as a way of preserving it as an open habitat and supporting the animals that call it home.  This week, the meadow conversation continues with a focus on all the cool ways that people are bringing meadows and meadow plants into their landscaping.  Really big meadows like the ones at Ward-Pound Ridge Reservation are impressive, but not feasible for the average landowner to own or maintain.  The alternative?  Small meadow gardens.        

Out with the lawn, in with the meadow!
Native meadows have become a fashionable, beautiful and ecologically intelligent type of landscaping over the past decade. Their benefits abound: they require far less water and mowing than a manicured lawn, they require ZERO fertilizers, their appearance changes with the seasons, they support populations of native plants and they attract a variety of wildlife. My friends in Pound Ridge - James and Ellen Best - have beautiful meadows incorporated into their landscaping; their backyard feels less like a generic landscape and more like real nature.  Here is what James and Ellen Best have to say about their meadow gardens:

What we like best about meadows is that they dramatically change with the seasons, unlike grass, which hardly changes at all. Cycles of purple, pink and yellow flowers, wispy grasses, buzzing bees and incredible spider webs appear in the meadows; it’s an ongoing show that nature puts on for free. We see fox, hawks, woodchucks, rabbits and more in the natural, protective habitat that the meadows create. After a dry, brownish winter, when the meadow begins to come alive again in the spring, it’s so exciting! Yes, patches of grass offer good foot-feel and space for activities, like a carpet. But how much carpet do you need? Less work, too!

A mowed path through a dense patch of wildflowers at the Best's property in Pound Ridge, NY

A patch of black eyed susan next to the Best's home in Pound Ridge, NY.

The Bests go on to say:
The combination of having both meadow and lawn areas seems like the best option. We have winding paths running through the meadows, making it an adventure to walk from one area to another. And it doesn’t have to be in a big area to give us that experience. Meadows provide borders and edges, as well as natural transitions from wooded areas to lawn areas – so much more alive than just a mowed lawn!

A tree swallow.  This bird can be seen flying over meadows picking off flying insects.  You are likely to attract these birds, especially if your meadow is near a pond. 

A lone cardinal flower grows in a patch of colorful flowers on the property of James and Ellen Best, Pound Ridge, NY. 

It seems as if meadow landscapes and native landscapes are popping up all over the place. In just a 20 minute internet search, I found all of the following websites.

See this company, which specializes in 'organic' landscaping.  Another company can consult on your property, or insall a thriving meadow.
See an example of landscaping turned wild here from North Salem, NY
Native U, a program at Westchester Community College, is dedicated to teaching gardeners and landscapers how to incorporate native plants and native ecology into their work.
A word from NY State on practicing native landscaping here
This Blog documents work in the 'Urban Lawn Reduction Project'.

Interested in managing the meadow on your property?
Check out this pamphlet on meadow management put out by the Mianus River Gorge.

Meadow management at the Armstrong Preserve.
On the Pound Ridge Land Conservancy's Armstrong Preserve there is an old field, which is colonized by invasive stilt grass and japanese barberry.  I recently drafted a Meadow Management Plan for the Pound Ridge Land Conservancy which outlines a long-term plan to bring native meadow plants back to the field.  Over the next five years we can expect more native grasses and wildflowers, bees, butterflies and dragonflies!     

*All pictures by James Best

Thursday, October 4, 2012

A meadow is a terrible thing to waste

The Pound Ridge Land Conservancy owns or holds conservation easements on 17 preserves in Pound Ridge, NY. The biggest - at 70 acres - is the Clark Preserve, on Autumn Ridge Road. This preserve is a fair representation of Pound Ridge's ecology; up high its got patches of exposed bedrock where oaks hang on for dear life, down low its got wetlands full of red maple and ferns, and everywhere in between grows a dry forest over hilly, rocky terrain. A unique feature of the Clark Preserve, and one that draws many each week, is its beautiful meadow. In the simplist terms, the Clark meadow is a refreshing change of pace; it permits a grand, open view and induces a feeling of expansiveness that the forest can not. Likewise, in ecological terms, the meadow refreshes the landscape; the open, grassy habitat supports mammals, birds, insects and reptiles that the forest does not. The bounty of the meadow interacts with the bounty of the forest to support those animals - such as the fox, hawk or box turtle - that rely on both ecosystems. An ecologist would say that 'the meadow increases landscape diversity'.   

Here, in the eastern part of the U.S., meadows don't usually stay meadows for long. This is really a tree's world and before long, every meadow will become colonized by woody plants. While on one hand this change is totally natural, on the other hand we have a limited amount of meadows left and, without active management, they would simply go away. Essentially, if we want meadows (which a lot of people like for a lot of different reasons) then we must mow them to keep out trees and shrubs. This is exactly what we did at the Clark Preserve last week.
A mower at the Clark meadow in late September. 

In this picture, half of the Clark meadow is mowed.  By the end of the day, the entire meadow was mowed. 

By mowing the meadow we killed the small shrubs that were starting to grow in the meadow.  The meadow's non-woody plants - grasses, flowers, ferns, etc. - will grow again next year.  In meadow management, different mowing cycles are used to benefit and attract different animals.  See this pamphlet, put out by the Mianus River Gorge, on the frequency and timing of meadow mowing. 

If meadows naturally turn into woodlands and forests, why should we keep a meadow open? 
Or, asked a slightly different way...
Aren't we interferring with natural succession when we mow a meadow?
Eastern meadows - when left a lone - usually become colonized by woody shrubs and trees through a somewhat predictable series of vegetation changes.  The following graphic depicts how a place's plants may change through time. 

A very general depiction of 'succession', the change in vegetation over time. 

So yes, it is well known that meadows turn into forests, but this does not mean that meadows are somehow less 'natural' or less important than forests.  As landscape features, meadows have always been right alongside forests.  If we consider the entire eastern forest - from the Mississippi River to the Atlantic Ocean - before it was dominated by industrialism, there were thousands of meadows dotting the forested landscape.  Fires would burn and open up forests to create meadows.  Beaver dams, after being breached, would drain their ponds and leave a wide open meadow.  Disturbances such as these were always making meadows out of shrublands and woodlands.  So at the same time as natural succession was turning meadows into forests, the forests themselves were being converted into meadows.  Within this simple equation, there was always a place for meadows in the eastern landscape and, thus, many animals evoloved to live within their open, grassy vistas. 

Today, its a different ballgame: fires are squelched and beavers are a mere fraction of their former abundance.  No meadows are being created while the remaining meadows proceed through succession into forests.  Given enough time, we will simply run out of meadows - hence the need for meadow management.  When we manage for a perpetual meadow we secure habitat for all the butterflies, birds, dragonflies and turtles that rely on them. 

Becuase of their ecological and cultural history, meadows are the focus of conservation in Westchester County.  Many uncommon birds and insects flock to these areas, attracting naturalists with binoculars and cameras.  The following are managed meadows open to the public:
Westchester Land Trust's Pine Croft Meadow  
Ward Pound Ridge Reservation
Bedford Audubon's headquesters is surrounded by fields
Marshland Conservancy
On a side note, I can reccomend two good books on the subject of America's historic landscape.