|By Joe Kosack
Wildlife Conservation Education Specialist
Pennsylvania Game Commission
Harrisburg, PA - Eastern bluebirds have long been the displaced darlings of
Pennsylvania's spring, as well as the poster bird for what can go wrong
when people introduce non-native species to a new area.
Bluebirds suffered considerable - almost unrecoverable - losses in the
twentieth century as a result of the injudicious introductions of house
(English) sparrows and European starlings to New York City - and ultimately
America - in the 1800s, and the toxic toll DDT exacted on many songbirds
and raptors for decades beginning in the 1940s. Further complicating the
bluebird's plight, particularly in Pennsylvania, has been the loss of open
spaces to development or reforestation.
Pennsylvania's bluebird population was probably its strongest ever in the
late 1800s and early 1900s, before starlings and house sparrows became too
plentiful, and before the advent of DDT. It was the period just after large
sections of the Commonwealth's forests had been logged off and a time when
farms covered about two-thirds of the state. Pennsylvania's human
population was half what it is today. Combined, that translated into lots
of open space - preferred habitat, few environmental issues and limited
competition with other cavity nesters. Bluebird paradise.
With time, though, America's bluebirds began to lose their grip. The
European transplants began to dominate the nesting cavities bluebirds
preferred. DDT and other harmful pesticides hampered reproduction until
they were banned nationally in '70s. And Pennsylvania's open spaces slowly,
but steadily, were reclaimed by trees, or worse, buildings. The bluebird's
perfect world was slipping away, and it was helpless to reverse the
troubling tailspin it found itself in.
|Bluebirds needed help
competing with the more aggressive European species, and American
ornithologists soon recognized this problem. By the 1930s, a national
movement had started to remedy the bluebird's "homeless" status. But
whatever gains were made for bluebirds likely were offset by the increased
usage of DDT - and a general disregard for many environmental concerns -
during the war years of the '40s.
"Bluebirds were in deep trouble in the mid 1900s, just before America's
environmental awaking in the '60s," explained Dan Brauning, Pennsylvania
Game Commission Wildlife Diversity Section chief. "Just about everything
seemed to be working against this handsome, and extremely popular songbird.
But the situation started to improve for bluebirds in the 1960s and '70s as
more and more Americans rallied to help by placing nest boxes in their
backyards and creating bluebird nest box trails."
The Game Commission regularly campaigned for bluebirds by encouraging
Pennsylvanians to consider getting involved in the fight to make the state
a friendlier place for them. But then the bluebird has always had someone
to champion its well-being in the Commonwealth, even before the creation of
the Game Commission in 1895. In the state's second oldest songbird
protection law, dated 1843, bluebirds were one of several species listed
specifically for complete protection in Allegheny and Franklin counties.
The $2 fine for breaking the law was equivalent to about a $50 fine today.
It's not hard to figure out why bluebirds were so popular in the 1800s, and
probably well before that, given their striking blue and orange plumage and
willingness to nest close to homes and in the fence-posts that once
separated farms and agricultural fields. John J. Audubon referred to the
bluebird as a "lovely bird ... full of innocent vivacity," and surely
countless Americans had similar feelings toward it.
The Game Commission's Howard Nursery, near Milesburg, has been
manufacturing bluebird nest boxes and box kits for more than a quarter
century. Each year, about 9,000 kits are manufactured there and sold or
provided to Pennsylvanians to help bluebirds. That annual influx of new
nest boxes helps to ensure Pennsylvania remains a "keystone state" in
|"That bluebirds currently nest
in all of Pennsylvania's 67 counties is directly related to the interest
Pennsylvanians have shown toward bluebird conservation and doing something
more for wildlife in their yards over the past 50 years," explained
Brauning. "But we should not consider the bluebird's comeback a done deal,
because their existence seems destined to hinge on the continued
involvement of people who care about the species. If people stop putting
out nest boxes for bluebirds, there undoubtedly will be serious
Bluebirds have the unique distinction of being the only member of the
thrush family to nest in a cavity. But they get plenty of competition for
nesting sites from other wildlife. In addition to house sparrows and
starlings, native species such as the tree swallow, house wren,
great-crested flycatcher, black-capped chickadee, and tufted titmouse also
use cavities. It's also not uncommon to find flying squirrels, white-footed
mice, deer mice, even yellow jackets and bumblebees using nest boxes.
Given the aforementioned list of possible tenants, it's not hard to
understand why nest boxes are in such demand. Add to that the diminishing
number of fence-posts found in rural America - caused by field
consolidation, farm loss, and use of prefabricated plastic and metal posts
- and the dwindling number of snags and mature trees with cavities in
Penn's Woods, and it hits you like a runaway train why bluebirds are so
dependent upon people and why their future will always be hazy.
Countless Pennsylvanians already are involved in bluebird conservation,
because they enjoy seeing bluebirds, or simply would like to lend a helping
hand to a songbird that could use all the help it can get. Most have
bluebird nest boxes in their yard; others maintain bluebird nest box
trails. Casual conservationists probably account for the biggest share of
this ongoing outreach effort. They also are responsible for putting nest
boxes in locations that simply won't do much for bluebirds.
"People frequently ask the Game Commission why bluebirds won't use a nest
box they've placed in their yard," said Doug Gross, Game Commission
ornithologist. "More often than not the reason is the box was placed in an
undesirable location. People often mistakenly place nest boxes in places
where they'd like to see them, rather than locations that satisfy
"A box is best placed on a post - not a tree trunk - four to six feet off
the ground in direct sunlight. Preferred locations are open backyards,
meadows, near fencerows or agricultural fields, and around cemeteries or
athletic fields. Boxes placed too close to houses and other buildings,
waterways and wetlands, or forested and brushy areas will attract nesting
competitors and predators."
|Of course, it should be
pointed out that a bluebird nest box used by any species other than a house
sparrow - starlings can't access the entrance of a properly-constructed
bluebird nest box - is still a box that's serving wildlife and helping to
fill a habitat deficiency. If helping bluebirds is your objective, then
place or relocate your nest box to an area where there will be limited
nesting competition and predator problems, and where bluebirds are more apt
to find it. If you're reusing a box, remove old nesting materials from
inside before hanging it. Otherwise, recognize its worth to other wildlife
and place it where it'll do some good.
The best time to erect a bluebird box is right now. The earlier a nest box
is placed afield or in a yard, the better its chances are of attracting
bluebirds. Males - the more vibrantly-colored ones - start shopping for
nest boxes in early to mid March. After attracting a female, they build a
nest in the box. In late April - and often again in mid June - the female
"Although Pennsylvania's bluebird population appears to be stronger today
than any time over the past 50 years, the species surely needs to remain in
the public's eye to ensure its well-being and that it continues to
prosper," emphasized Gross. "Probably nothing reinforces the need for
bluebird nest boxes more than seeing bluebirds scrapping with house
sparrows over a box. It's a sight that inspires people to get a nest box
and help make a difference locally. So please do put out nest boxes, and
put them where they can help. Please encourage your neighbors to do the
The Game Commission's website -
- offers additional information on bluebirds, as well as nest box plans.
The agency also will be selling bluebird nest boxes and nest box kits to
the public in May in the Harrisburg headquarters.
The Bluebird Society of Pennsylvania (www.thebsp.org),
as well as the North American Bluebird Society (www.nabluebirdsociety.org),
have done much to promote bluebirds and the species' never-ending need for
nest boxes. Their websites offer a variety of features that will
familiarize interested landowners with ways to make their properties more
attractive to bluebirds.
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