The
Campus Natural Areas (CNA) have long been known for their birds.
Early in Madison's history, people hunted at University Bay.
Subsequently the CNA was used for education, research and bird
watching.
Bird populations change through the seasons. Spring and fall are
the most diverse periods. The bird populations of the CNA have
changed through the years, reflecting the modifications of the
landscape from wilderness to agriculture to urban natural area
and the variations in the bird populations of Wisconsin .
Below is a seasonal selection of the birds that are seen in the
CNA along with some history.
Winter
Winter has the lowest diversity and the least predictable species
composition. In some winters the CNA hosts winter finches, northern
owls, and late migrants. Some interesting birds also occur regularly.
• Tundra Swan Tundra Swans usually appear in late
fall after the boats leave and stay until the lake freezes over.
In the recent warm winters there have been several hundred swans
during the holidays. In early January, 2005, 269 swans were observed
in University Bay . They may also visit the CNA for short periods
earlier in the fall and in the spring.
• Bald Eagle Bald Eagles can be seen in any month
in the CNA, although they are more common in late fall, winter,
and early spring when there is open water. They are most often
seen in the dead trees at the base of the Biocore Prairie and on
Frautschi Point. Four Eagles visited Frautschi Point for several
weeks this past December. In the nineteenth century Bald Eagles
nested in southern Wisconsin and were regularly reported at Eagle
Heights . They declined through the 1950s and 1960s, becoming endangered,
because DDT lowered their reproduc-tive success. Subsequently the
Eagle population has increased greatly. In 2004, for the first
time in years, Eagles again nested in the Madison area.
• Great Horned Owl The Great Horned Owl is a year
around resident, most frequently seen roosting during the daylight
at Eagle Heights Woods, Frautschi Point and Picnic Point or hunting
during the twilight in the gardens or at the Class of 1918 Marsh.
The Owls are most obvious during the winter, when they court, build
nests, and lay eggs. They can often be found by following the excited
crow mobs (crows also mob hawks) and by hearing their 4 to 8 deep hoos in
the early morning or late evening. In 1944 Aldo Leopold noted the
importance of these Owls to field ecology education and their reliance
on mature trees.
• Screech Owl Another year around resident, the Screech
Owl, is most visible in winter when it suns in holes in trees.
Multiple pairs of this small Owl live in the CNA, but they can
easy be overlooked. Surprisingly, I have never heard their eerie
call in the CNA.
Spring
Spring is the most popular time to observe birds in the CNA. Waterfowl
diversity peaks as the ice breaks up in University Bay . Song bird
diversity peaks in May.
• Common Loon The Loon has become a symbol of northern
wildness, but it can be seen and heard (more often on foggy or
cloudy days) in the spring and fall on Lake Mendota . A few spend
the summer on the lake.
• White Pelican Recently the spectacular White Pelican
has soared over the CNA in May. After almost totally disappearing
from Wisconsin , the Pelican now nests in Horicon Marsh and Green
Bay and summers along the Mississippi River .
• Osprey Osprey can be found during migration. In
recent years, since they have nested in the Madison area, they
can also be found fishing in the late summer. Like the Bald Eagle,
the Osprey has increased significantly since the banning of DDT.
• Sandhill Cranes In recent years a Crane pair has
nested, occupying University Bay and the Class of 1918 Marsh in
different years. The Cranes are most visible feeding near the Class
of 1918 Marsh and in the soybean fields (summer). The Sandhill
Crane has made a dramatic recovery in Wisconsin , after almost
disappearing in the 1940s.
• Warblers Picnic Point is perhaps best known for
the May (1-20) visit of the warblers. These tiny, brilliant, hyperactive
birds arrive in waves with the southern winds. Usually 29 species
of warblers are seen annually and often someone finds some of the
rarer species, especially if there is a good fallout. Most of these
warblers also visit in fall (when they are easiest to see at Frautschi
Point, the Picnic Point Marsh, and the open areas and gardens),
but they are confusing fall warblers and are harder to see because
of the leaves.
Neotropical Migrants In addition to Warblers, in May and September
the CNA hosts numerous birds that winter in the tropics, including
flycatchers and thrushes. The abundant Baltimore Orioles and Indigo
Buntings are most obvious in the first three weeks of May, but
also nest in the CNA. Scarlet Tanagers and Rose-breasted Grosbeaks
can be readily found in May.
Summer
The CNA supports a diverse set of summer birds. The Breeding Bird
Study (2000-2002) confirmed 69 species and another 12 probably
bred (Lenehan, Habitat and Abundance of CNA Breeding Birds,
2003).
• Green Heron The Green Heron is regularly seen quietly
feeding around University Bay and the Class of 1918 Marsh. At least
one pair nests annually.
• Great Blue Heron Great Blue Herons visit University
Bay to feed, but do not nest in the area.
• Canada Goose Canada Geese were reintroduced and
now spend most of the year and nest in the area.
• Wood Duck The spectacular Wood Duck nests throughout
the CNA, wherever there are mature trees with large holes. In April
these ducks scout the woods. While the females incubate eggs, the
males rest at the Class of 1918 and Picnic Point Marshes. Wood
Ducks disappeared and were reintroduced by Robert McCabe into the
Arboretum in the 1940s.
• Red-tailed Hawk The Red-tailed Hawk spends most
of the year in the CNA, but is most obvious when the pair's large
begging young occupy the old field edge. Cooper's Hawk The usually
secretive Cooper's Hawk can often be seen hunting for birds along
the edge of the Biocore Prairie or the Class of 1918 Marsh. Several
pairs of Cooper's Hawks nest in the CNA. This species almost disappeared
from southern Wisconsin by the 1970s, but after DDT was banned
it recovered and colonized many urban areas.
• Rails Virginia and Sora Rails nest in the Class
of 1918 Marsh. These rails are most active in early morning and
late evening. They can be most easily seen during high water when
they are forced to cat-tails edges close to the land or during
very low water when they have to feed at the interior edge of the
cattails. More frequently their descending whenny (Sora) or deep
grunts (Virginia Rail) are heard.
• Killdeer In late May the Killdeer can be observed
behind the Class of 1918 Marsh or in the Eagle Heights Gardens
giving its broken wing act to lead predators (people) away from
its nest.
• Terns Although no terns breed in the CNA now, Black
Terns bred in the past at the Class of 1918 Marsh. Caspian Terns,
with their large red beaks, periodically appear on the sandbar
in University Bay .
• Belted Kingfisher At least two Kingfisher pairs
nest in the CNA in holes in earthen banks. They can be observed
sitting on a snag waiting or diving for fish. Their loud rattling
call helps locate them.
• Neotropical Migrants Comprising 40 % of CNA breeding
birds, these species include flycatchers (5 species), swallows
(5), vireos (3), and warblers (6). Fall
Many CNA bird species can be found during a longer period in the
fall than during the spring. Fall waterfowl numbers are also larger
and more predictable.
• Great Egret Great Egrets visit the Class of 1918
Marsh and University Bay most years in late summer. Occasionally,
when food is favorable (like during the flood of 2000) more Egrets
come or they stay for longer periods. This species almost disappeared
from southern Wisconsin , but has increased recently.
• Black-crowned Night-heron Like Great Egrets, Night-herons
visit the CNA annually, usually in the late summer. They are usually
observed feeding near Willow Creek or at the Class of 1918 Marsh.
• Dabbling Ducks Most years, when the Class of 1918
Marsh has enough water, many dabbling ducks occupy the Marsh. Beginning
in late summer, other ducks join the resident Mallards and Wood Ducks:
first Blue-winged Teal, then Shoveler (also common in spring), Gadwall,
and American Wigeon. Pintail and Green-winged Teal also visit the
Marsh.
• Diving Ducks Once University Bay was famous for its
diving ducks, but today they appear in numbers only late in the fall
after most boats leave the lake. From 1946 to 1980 fall ducks were
counted several times weekly by 54 Wildlife Management Tech-niques
class students. University Bay was known for its periodic large number
of Canvasbacks (2000 in 1914 and 1634 in 1954). Bufflehead (throughout
spring and fall), Goldeneye, and Common Merganser still occur in
relatively high numbers in the Bay.
• Turkey Turkeys completely disappeared from Wisconsin
. Reintroduction has been so successful that Turkeys have recently
colonized the Madison area. They appear occasionally in the CNA,
although they have not been found nesting there yet. Most CNA observations
are from fall and winter.
• Shorebirds Shorebirds occur in the CNA when there
is appropriate habitat. In spring they often feed in the puddles
behind the Class of 1918 Marsh and rest on the University Bay sandbar.
They feed in the 1918 Marsh when it is low in the late summer and
fall. Repeated visitors include Spotted Sandpiper (breeds), Snipe
(annually), Solitary Sandpiper (regular spring and fall), both Yellowlegs,
and Least and Semipalmated Sandpipers.
• Sparrows The Eagle Heights Gardens and the Biocore
Prairie host a wide variety of sparrows in September and October.
Their diversity (12 species can often be found during the fall) and
their visibility makes this one of the best places in Madison to
practice the art of fall sparrow identification. |
