I designed a restoration and conservation plan to improve the island habitat and native special at the Cedar Creek/Lake Muhlenberg region of Allentown, PA. My research proposal was part of an interdisciplinary Sustainability Studies course where each student selected a real environmental issue facing the City of Allentown in which the Parks and Recreation Department desired to improve. My proposal was actually picked up, funded by, and put into action by various partners who contributed their expertise to the project, such as the Edge of the Woods Nursery in Allentown, a nonprofit organization Friends of the Allentown Parks, and the Lehigh Valley Chapter of the National Audubon Society

1. The Ecological Issues
ISLAND RESTORATION AND
REHABILITATION PLAN:
LAKE MUHLENBERG
By: Nina Sanders
Local Sustainability
Fall 2013
Abstract: Lake Muhlenberg, located in Cedar Creek Park, is the largest lake
in Allentown. Since the start of its artificial creation through damming Cedar
Creek during the early twentieth century, the lake has suffered some serious
ecological issues. However, through a combination of restoration efforts, the
lake and island have the potential to return to a more natural and sustainable
state. The island restoration and rehabilitation plan lays out an improved
habitat to be created on the island through introducing a variety of native
plant species (shrubs, trees, and other vegetation) and installing habitat
structures (bat boxes and a chimney swift tower). The efforts will help
enhance Lake Muhlenberg as a public destination point, as well as encourage
the return of many bird species and give those already nesting in the park a
better environment. In addition, the designed habitat will deter the
problematic Canada Geese population in Lake Muhlenberg.

2. Sanders 1
Ecological Issues
Lake Muhlenberg, located in Cedar Creek Park, is the largest lake in Allentown. From
the start of its artificial creation through damming of Cedar Creek during the early twentieth
century, the lake has been suffering some serious ecological issues. Among the leading problems
with the lake include the overpopulation of invasive geese, which are creating increased levels of
goose guano in the area. Cedar Creek Park was designed and constructed long before the now
common resident Canadian Geese were abundant. However, the park contains landscape features
ideally suited for these geese, such as a good supply of flowing fresh water, open expanses of
shortly trimmed mowed grass lawn, and the island that serves as a suitable nesting habitat. When
people feed the Canadian Geese and other waterfowl in the park, this only worsens the problems
associated with them. Today, large numbers of resident and migratory Canada Geese congregate
in the park, and their excrements in excess are linked to both disease spread and eutrophication
of the lake (friendsofanimals.org). With eutrophication, an overgrowth of algae due to the
excessive richness of nutrients being absorbed from the fecal matter into the waters, comes
decreased Oxygen levels within the water. Low Oxygen levels remain an issue in Lake
Muhlenberg, even with the presence of the natural spring that helps circulate the water. If
Oxygen levels are not restored to normal, the native marine life, other animals, and plants that
depend on the health of the water in the lake will be impacted.
Lastly, because the lake suffers from sediment build up, it requires frequent dredging
processes that are only temporary fixes until the sediments return and collect before the next
dredging effort. The cycle of having to regularly dredge the lake has various unwanted side
effects. Even though the activity is required to remove unwanted deposits in the water, the
processes have negative environmental effects, such as altering the natural pre-disposed
composition of the soil deposits. Furthermore, the alteration is disrupting an existing habitat of
organisms and wildlife that depend on the original composition of the soil. When changes form
dredging are made, this poses problems because it creates and transfers newer and unwanted
organisms to other parts in the water, leading to a more prevalent spread of contamination and
release of unwanted nutrients in the water. The polluted water and adverse environmental effects
of dredging have huge biodiversity impacts, but in an effort to restore the ecosystem health of the
lake, the partners working on Lake Muhlenberg’s restoration efforts have high hopes that
through a combination of restoration efforts, the Lake and island can return to a more natural
and sustainable state. Already decided by local partners as part of the restoration in regards to the
island is the removal of the land bridge that cuts off circulation within the lake. Currently, the
land bridge is a strip of no more than 6 or 7 yards of a soil-gravel blending with minimal plant
life growing on it. Other than the few erroneous looking grassy patches dispersed throughout the
land bridge, it is essentially a strip of combination wet-dry soil with dark pebbles and gravel
continued from the path on the perimeter of the lake. Without the land bridge, public access will
be restricted on the island, but the potential of enhancing free-flowing stream activities, lowering
the maintenance costs on the island, and significantly reducing the problems associated with the
geese populations are among the benefits of transforming the island into a free standing mass.

3. Sanders 2
Recommended Native Plants for Landscaping on the Island
Through extensive research on native plant landscaping in Pennsylvania, and contact with
local partners Louise Schaefer, B.S. Biology PA Certified Horticulturist from Edge of the Woods
Native Plant Nursery, and Peter Saenger, Acopian Ornithological Specialist, President of the
Lehigh Valley Audobon Society and staff member of Muhlenberg College’s Biology
Department, I have determined an appropriate landscape design for the island region. The
following species of trees, shrubs, and grasses have been selected because they tend to grow
wildly throughout the state of Pennsylvania and will likely do well if they are planted in their
preferred growing conditions. Furthermore, none of these plants are rare, endangered, threatened,
or extinct in the state, but rather they are commonly cultivated native species and available for
purchase (Edge of the Woods Nursery). All of these plants will provide both food and cover for
the wildlife we are seeking to attract as well as reduce near the Island and Lake.
Medium to large Trees:
1 River Birch
The River Birch, also known as the Red Birch, would be an appropriate native tree for the
Island for its ability to thrive on moist sites, swamps, flood plains, and river banks. It is also
useful to control erosion. It is a low maintenance, fast growing, long-lived tree that will attract
the designated native birds to the island as well (wildflower.org). Reaching approximately 30-50
ft in height, this tree is often slightly leaning and has long ascending limbs that would provide
sufficient shade next to the area of the Bat Box, which is explained in detail below.
1 Red Maple
The Red Maple, or Scarlet maple, is another popular ornamental tree that attracts birds
due to its red fruit and flowers. It grows 40-50 feet and is known for its notable pink-red flowers
in the spring time, and red fall foliage, which would be pleasingly aesthetic on the island all year
round. The Red Maple tends to prefer moist, swampy sites and is very tolerant of a range of soil
conditions. It would be placed in the area of the island in part shade, part sun, due to its light
requirements. The Red Maple is used by a variety of birds for nesting, including the blackbird,
Screech Owls, and the native Waterfowl such as Wood Ducks which are already present on the
island and will be more abundant with the addition of Wood Duck Boxes in the Park.
blackbirds.

4. Sanders 3
Plants to Address the Geese Issue
The period that annually attracts the most birds to the Muhlenberg Lake remains late
winter. During this timeframe, large numbers of migrating waterfowl normally appear in addition
to the already large numbers of both migrating and resident Canada Geese in the area. (Some of
the geese that reside in Lake Muhlenberg are resident and some are migratory. Resident geese
live in the same area year round). Once these geese have chosen a spot near the lake, they tend to
take up residence there or return to the same nesting spot every year (Pennsylvania Game
Commission). In order to discourage the geese from using the Island as a common nesting
ground, all of the grass on the Island will be replaced with native vegetation that is less attractive
to the geese. Using vegetation to deter geese is an alternative, more humane measure than using
canon sounds to scare the geese, or introducing a new predator to kill them off, which have not
worked in Allentown in the past and which according to Audobon International, are only short
term control methods (Rodale.com). It is crucial that the changes to deter the geese from settling
down on Lake Muhlenberg property happen before the spring nesting season.
Canada geese are attracted to very short grass, so any grasses that are higher than 6
inches at most is a good technique to discourage geese from settling in the area. The common
lawn turf that currently exists on the majority of the island will be replaced with three types of
native grasses: Riverbank wild-rye, Virginia wild-rye, and Little Blue stem. These three grasses
will be mainly grown around the perimeter of the island to deter the Canada Geese population
from nesting and settling in the island area. They are all very versatile and good for stream bank
conditions that exist on the island. They can tolerate a wide range of soil, and can grow in
sunlight and shade. Using these tall, grassy plants as a control tactic in addition with boosting
other waterfront vegetation on the island near the water’s edge will increase the native bird
species, decrease the geese population, and help beautify the island.
1. Riverbank wild-rye: A good waterfront vegetation for stream bank conditions with wet
and moist soil, grows about 3-5 feet tall, and can grow in sunlight and shade (Edge of the
Woods).
2. Virginia wild-rye: Tolerates a wide range of conditions, grows 2-4 feet tall, and can
grow in any kind of light exposure (Edge of the Woods).
3. Little bluestem: A clump grass that prefers sunny, riverbank areas, tolerates poor dry
soil, and grows 2-4 feet tall (Edge of the Woods).

5. Sanders 4
Structures to attract Birds and Bats to the Island
In addition to a native plant sanctuary, a large new use for the island will be a friendly
habitat for birds and bats. Given that the island will be eventually permanently closed off from
people due to the removal of the land bridge, the restoration efforts of planting and creating the
following bird/bat structures will need to be implemented before the land bridge island access is
cut off: a Chimney Swift tower, and a bat box.
Chimney Swift Tower
The purpose of placing a Chimney Swift Tower on the island is to attract the modern
Chimney Swift birds by providing them with additional nesting habitats. The Chimney Swifts
have been roosting in chimney’s in Pennsylvania, the Eastern United States, and Midwest for
hundreds of years. They roost communally once their breeding season is over, and migrate to
South America for the winter. During the spring, the Chimney Swifts in Pennsylvania can be
found nesting in chimney’s near wooded slopes and humid forests, but with the loss of their
natural habitat of hollow trees in old growth forests, and modern chimneys being capped and torn
down, the Chimney Swift populations are declining rapidly. In 2010, the International Union for
the Conservation of Nature changed the Chimney Swift’s status from “Least Concern” to “Near
Threatened” (chimneyswifts.org).
Since Chimney Swifts rely on the insides of chimneys as their primary nesting and
roosting sites, building an artificial nest on the island can help with efforts to attract and conserve
this species by Lake Muhlenberg. The towers are typically freestanding, and located in a partially
wooded and partially shaded area. On the island, it will be situated beneath either the Maple or
Birch Trees, or wherever the Lehigh Valley Audubon Society deems most appropriate. The
structures are approximately 8’ tall, 14” in diameter, and built with varying materials, including a
combination of wood or cider-blocks for proper interior insulation, and a light vinyl or hard-
panel siding to complete the exterior. Construction costs may vary from anywhere from $100.00
to $400.00 (chimneyswifts.org).
What other benefits will the Chimney Swift Towers bring to the lake and why should we
care about saving them? With more insect-eating Chimney Swifts frequenting the area, there will
be fewer flies and mosquitoes. In addition to consuming insects and causing little trouble to
disturb the nature, attracting the Chimney Swifts through the use of the tower could also attract
the public interested in seeing what these large structures are and distinct happy bird sounds of
the swifts. From a distance, or from the viewing platform designed by our peers, park visitors
could gaze out onto the island and try to identify the various birds and Chimney Swifts flying
about. Lastly, there is hardly any mess or cleanup associated with the tower, which only needs to
be cleaned once a year when the swifts are migrating (www.learningthebirds.com).

6. Sanders 5
Bat Boxes
In the Lehigh Valley region of Pennsylvania, bats belong to the Family Vespertilioniadae,
also known as evening bats. These bats eat insects and often feed over water. It is a good idea to
attract bats to the island of Lake Muhlenberg because it is an ideal habitat to help repopulate this
declining species. Also, more bats near the island means less mosquitos and invasive beetle and
moth species which the bats feed on. Other Pennsylvania bat species known to use the boxes are
the Little and Big Brown Bats, and Northern long-eared bats. All of these bats are constantly
looking for suitable alternative roosts, and having a bat box near the island region can support
hundreds of bats at a time, varying on the size of the box. The standard three chamber bat box
can house around 100 to 300 bats, ranges from 18 to 24” wide, 2’ tall, 4” deep, and weights
around 12 pounds. According to the Pennsylvania Game Commission, you can purchase a bat
box or assemble one on your own, but an assembled box costs around $50.00 to $80.00. The bat
box should be placed at least ten feet off the ground in an open area oriented south-southeast
where it receives at least seven hours of direct sunlight a day. The bat house should be located on
the wooden electric pole on the island. It is typical for bat boxes to be located on wooden
structures such as poles, rather than trees that provide too much shade. The ideal location of the
island pole will give it plenty of sun exposure and attract bats due to its proximity to the lake. Bat
boxes are more attractive if located within 1500 feet of a permanent freshwater stream or pond
because they use the water for drinking, and it guarantees a feeding zone.
Chimney Swift Tower and Bat Box Design

7. Sanders 6
More trees and shrubs that will be planted:
 Gray Dogwood
 Silky Dogwood
 Red twig Dogwood
 Elderberry
 Red and Black Chokeberry
 Inkberry, American Holly
By creating a decent habitat on the island through planting native shrubs and trees and
using built habitat structures, many bird species are possible. Orchard & Baltimore Orioles
already nest in the park, so giving them a better environment will greatly help them. Chickadee
species, Song Sparrows, Gray Catbirds, Tree Swallows, Blue-gray Gnatcatchers, and Common
Yellowthroat and Yellow Warblers all are possible to nest on the island as well. More target
birds include the Chimney Swifts, Screech Owls, Gold Finches, Black Birds, and Blue Birds.
The ornamental Dogwood trees are particularly good for aesthetic beauty as well as for their
flowers and berries that bloom in cool shade and are edible to birds. They can grow up to 30 feet.
The Elderberry is a deciduous shrub that grows best on the edges of riparian buffer zones, in a
wide variety of wet to dry soils, and part shade. Its berries also attract bird species. The
Chokeberry is a smaller, flood tolerant bush that reaches around 3 to 6 feet tall. Its clusters of
purple and red fruit attract birds as well. Finally, The American holly ranges from 25 to 60 feet
tall, and blooms bright red berries (wildflower.org). Berries only occur on the female plants and
grow in lower light situations, so these plants would be placed in a variety of locations on the
island in abundance to guarantee the opposite sex is growing nearby. It can tolerate moist, well-
drained soils and attracts birds. In addition, it has a special value to honey bees, butterflies, and
moths of North America (Edge of the Woods). The diagram below explains the placement and
design of the plant sanctuary on the island:

8. Sanders 7
Planning for Longevity
The proposed plan can only be as effective as the efforts of those put toward instituting
the changes. With the help of bird and habitat specialists of the Lehigh Valley chapter of the
National Audobon Society, the habitat designs and native vegetation recommendations will be
reviewed, approved, and/or altered appropriately. The Society members will also be in charge of
coordinating the manual labor and volunteer work required to construct the bird nesting boxes
and houses, Chimney swift tower, and any sort of initial or ongoing maintenance required
throughout the project. Furthermore, the Edge of the Woods Nursery specialists will also provide
more details and recommendations on native vegetation design. The bulk of their duties,
however, will involve the hours put in to assist with the plantings, providing the actual plants
themselves, and creating a minimal upkeep native vegetation maintenance plan, if needed
The ultimate purpose of the Island and Lake Muhlenberg conservation efforts is to restore
the island as a natural habitat, while maintaining its integrity, enhancing the ecosystem health of
the lake, and keeping the lake as an attractive place. When the island “beautification” processes
have been completed, we hope that its habitat enhancement will attract native bird species, deter
the Canada Geese, and make Muhlenberg Lake as a whole more attractive. In addition, the island
appeal gained from other restoration efforts proposed by Muhlenberg College students will
increase public awareness of the Lake as a destination point.

9. Sanders 8
Resources
"Build a Bat House." - National Wildlife Federation. N.p., n.d. Web. Apr. 2013.
<http://www.nwf.org/How-to-Help/Garden-for-Wildlife/Gardening-Tips/Build-a-Bat-
House.aspx>.
"Chimney Swift Towers." Chimney Swift Towers. N.p., n.d. Web. Apr. 2013.
<http://www.learningthebirds.com/Archives/Columns/ChimneySwiftTowers.htm>.
"ChimneySwifts.org." ChimneySwifts.org. N.p., n.d. Web. Apr. 2013.
<http://www.chimneyswifts.org/>.
"Geese." Friends of Animals. N.p., n.d. Web. Apr. 2013.
<http://www.friendsofanimals.org/news/geese/>.
"Green Landscaping: Greenacres." EPA. Environmental Protection Agency, n.d. Web. Apr.
2013. <http://www.epa.gov/greenacres/nativeplants/factsht.html>.
"Home - Edge Of The Woods Native Plant Nursery." Edge Of The Woods Native Plant Nursery
RSS. N.p., n.d. Web. Apr. 2013. <http://www.edgeofthewoodsnursery.com/>.
"Native Plant Database." NPIN:. N.p., n.d. Web. Apr. 2013.
<http://www.wildflower.org/plants/>.
"We Recommend." 8 Ways to Deal With a Goose Invasion. N.p., n.d. Web. Apr. 2013.
<http://www.rodale.com/geese-control>