- April is a month to watch lakes and reservoirs on a
daily basis; migrants can drop in, rest briefly, and
depart. The more miserable the weather, the more likely
stray migrant waterfowl, shorebirds, and terns will appear.
Birding in cold, driving rain is no fun, but the
possibility of finding something unusual or truly rare is
a powerful goad to the dedicated field birder. Early in
the month, days with northwest winds are sometimes
dismissed as too early for most passerines and too late
for much waterfowl. It is true that a day spent in the
cold wind may produce nothing. On the other hand, the
first 10 days of April, under less than ideal conditions,
have produced a major waterfowl fallout on Triadelphia
Reservoir, an American Bittern at West Friendship Park, a
Black Scoter at Centennial Park, and a Short-eared Owl at
Alpha Ridge Landfill.
- April is a transitional month. Although many birders
are used to starting near dawn to catch peak feeding
activity and movement, this is a month when almost any
time of the day can be productive. If there has been a
significant change in cloud cover, temperature, or wind
direction during the day (showers in the morning,
clearing by afternoon), the late afternoon/evening hours
may be more productive than the morning. Terns, gulls,
and swallows may appear over lakes; smaller passerines
may suddenly become active; and raptors may be seen
soaring. If rain or a cold front is forecast to move in
during the day, try to take advantage of early sunshine
and favorable winds. After the winds have shifted to the
northwest and are blowing steadily, there is a chance
that migrating waterfowl will drop onto local lakes and
reservoirs until the winds diminish.
- Blue-winged Teal are usually passing through during
April. Check the shallow end of Centennial Lake
as well as Forebay Pond.
- Long-tailed Ducks may drop onto the larger lakes and
reservoirs during late March and early April, especially
during periods of stormy weather.
- This is the month to look for Red-throated Loons on
Though the heaviest state Red-throated Loon movement
occurs in March, most of this county's few records are in
- Common Loons migrate well into May and are occasional
to regular on county lakes as well as on the reservoirs.
Throughout this month and part of May, singles and
flocks may be seen as flyovers, mostly from dawn until 10:00 a.m.
almost anywhere in the county.
- Most Pied-billed Grebes and the majority of
mergansers leave by the end of April.
- Migrating Double-crested Cormorants will be passing
through all of this month and well into May. Early to
mid-morning is the peak time.
- American Bitterns should be looked for all month
until mid-May. Meadowbrook Park, with its large patches
of cattails, has proven attractive to this species. They
have also been seen at a cattail-covered pond at the
intersection of Race Road and Hanover Road.
- The first week of April may see the return of the first
Green Herons, although the third week is more likely to
see a surge in numbers.
- Most spring Glossy Ibis records are from the first
week of April through the first week of May.
- Although the earliest Ospreys begin to drift through
in March, many more move this month with migration
continuing well into May.
- Check main forks of large deciduous trees before the
leaves have reached full size for nesting Red-shouldered
and Red-tailed hawks. Red-shouldered Hawks, which are a
common stream or river valley nester, sometimes may be
seen carrying identifiable prey items such as snakes,
frogs, and small rodents.
- Northward-moving Broad-winged Hawks are most visible
from the middle of the month into early May.
- Although Soras have been observed as early as the
first week of April and as late as the third week of May,
late April to mid-May appears to be the peak migration
period. Muddy edges of islands at Centennial Park and
pond edges with adjacent wetlands at Meadowbrook Park
offer accessible places to watch and listen for this
- Shorebirds (other than Killdeer, an occcasional yellowlegs, Wilson's Snipe, and
American Woodcock which arrived earlier) begin appearing
in numbers after the middle of the month. Check muddy
areas around the western islands at Centennial Park from
late March until the vegetation grows up. The pond at the
entrance to Western Regional Park has proven productive
unless rainfall has filled it completely. Browns Bridge
mudflats are usually covered at this season. Shallow pond
and river edges anywhere in the county may produce a few
birds. Wet spots in fields, especially on turf farms
where the sod has been stripped, may also be suitable
habitat. Shorebirds should be found in good numbers
throughout the first part of May; few are noted after
- Bonaparte's Gulls and Caspian Terns can be seen
sporadically this month and into May resting on or flying
over the county's larger lakes and reservoirs. Wilde
Lake, for reasons known only to the Bonaparte's, was the
favored lake for these gulls for many years. The last few
years have broken that pattern so that Centennial and
Triadelphia Reservoir are also frequently visited. Caspian
Terns, although sometimes reported as early as the first
week of April, are more often seen later in the month and
are likely at any of the central lakes or the reservoirs.
- There is a resurgence of Barred Owl calling in late
April and May, sometimes during daylight hours.
- By late April, watch at dawn or dusk for early Common
Nighthawks. Most migrate in May.
- Occasionally, someone reports a Whip-poor-will
calling at dusk or dawn. These are migrants, normally
present only a single night. Nesting (if it still occurs in the county) is
probably confined to a few areas in or near Patuxent
River State Park; currently, there is no location that can
be pinpointed with certainty.
- Chimney Swifts begin to filter in around the middle
of the month; numbers are often small until closer to the
beginning of May.
- There are a few Ruby-throated Hummingbird records in
early April, but more appear from mid-month on. Most come
through in early to mid-May.
- Look for Red-headed Woodpeckers late this month and
most of May. Areas of mature oaks and hickories with
little or no understory and numerous dead trees are
primary nesting habitats; in migration they can turn up
in almost any mature deciduous woods.
- In most years, Yellow-bellied Sapsuckers can be
spotted throughout the month.
- Eastern Kingbirds begin showing up the last 10 days of
the month. Great Crested Flycatchers usually begin to
appear the last week of April or the first week of May
with arrival continuing into late May.
- Most Blue-headed Vireos migrate through the last
third of April and the first week of May; numbers taper
off rapidly after that. Alpha Ridge Park has been a
dependable place to find them.
- White-eyed Vireos begin appearing the last third of
- The number of swallows over lakes and reservoirs
rises this month. There may be a few days when hundred of
swallows of several species are present over local
lakes. Barn Swallows nest under the deck at Centennial
Park and beneath the bridge at the east end of Lake
Elkhorn. Rough-winged Swallows normally nest in
riverbanks; however, they have been seen attempting to
nest in bridge drains including those at the west end of
the lake at Centennial Park.
- Most years nesting Cliff Swallows return to Brighton
Dam by mid-April. A significant colony also exists at
Sykesville under the MD 32 bridge over the Patapsco
- Continue to listen and look for Red-breasted
Nuthatches until the first few days of May. Areas of
pines at Pigtail and Big Branch are possible locations.
- House Wrens can arrive anytime this month; most
records are after the first week.
- Marsh Wrens should be sought the last week of April
and the first three weeks of May in any wetland habitat
containing even a few cattails or areas of soft rush.
- By mid-April the high, thin song of Ruby-crowned
Kinglets can be heard. Most Golden-crowned
Kinglets (the common winter kinglet) have moved on.
- Blue-gray Gnatcatchers begin nest building as soon as
they arrive. The beautifully constructed compact nest
looks like a knot on a horizontal branch. Nests are often
easy to locate because the birds usually choose an
open-branched tree like black walnut and build before
leaves have emerged completely.
- With favorable weather, Eastern Bluebirds may begin
nest building the first half of the month.
- Heaviest Hermit Thrush migration is the first half of
the month, with Wood Thrushes and sometimes Veeries
making appearances the last third of the month.
- The earliest Gray Catbirds show up by the third week
of April, peak numbers do not occur until the first 10
days of May.
- The last third of the month may produce early records
for some warblers, but only small numbers are present
except for a few typically early species. The earliest
warblers are Pine (March), Louisiana Waterthrush (usually late March
but more obvious in early April), Yellow-throated (late March to mid-April),
and Palm (sometimes a few in March, more likely early April).
By the last half of the month, watch
for Common Yellowthroat, Northern Parula,
Ovenbird, and American Redstart, as well as Yellow,
Black-and-white, Prairie, Prothonotary, and Hooded
- Although Prothonotary Warblers have been recorded
from mid-April through May, the peak period is the last
10 days of April and the first week of May.
- Rockburn Branch Park and Pigtail are good places to
hear singing Pine Warblers.
- To find Yellow-throated Warblers, try Marriottsville
Road east along the river (especially the first half
mile) and west to the tunnel—sometimes it is not even
necessary to leave the parking lot! Another location
where they have been regularly recorded is in the
vicinity of Henryton Road at the river. Both the parking
area at the dead end and the path west along the Patapsco
River are worth investigating. A few times they have
arrived in late March, more often it is early to
mid-April. This species and Louisiana Waterthrushes both
sing loudly and exuberantly in the Patapsco River
floodplain before the trees have leafed out. From a
distance, it is possible to mistake one species for the
other as the songs have similarities. Seek out the
Yellow-throated Warbler high in large sycamores along the
river; waterthrushes are more likely to be bobbing along
the muddy edge of the river or perched on a relatively
- Generally, the most productive areas for songbird
migrants in late April and early May are places not far
from water which contain flowering oaks, hickories, box
elders, and willows. Southern and eastern locations such
as Schooley Mill Park, Rockburn Branch Park, the
Avalon/Orange Grove section of Patapsco Valley State
Park, and trails near Savage are good options. Sometimes
northern areas, such as Daniels or Henryton, can be
rewarding despite slow leaf development; on the other
hand, they can be devoid of migrants on a clear, chilly
morning. By the second week of May, central and northern
locations have the edge so that the Middle Patuxent
Environmental Area, Patuxent River State Park, and
northern sections of Patapsco Valley State Park may be
the most rewarding. Early morning birding during the
chilly days of early April may not be as productive as
the late afternoon.
- A few Yellow-rumped Warblers usually winter, but the
last two weeks of April see peak numbers of our most
common migrant warbler. Sometimes hundreds may be seen
along the water's edge at Centennial Park or Lake Elkhorn.
- In late April and early May, check Palm Warblers
carefully for the paler western subspecies whose numbers
peak in late April. Palm Warblers are frequent along lake
edges at Centennial and Lake Elkhorn at this time.
- Grasshopper and Vesper sparrows should arrive—the
former mostly in late April and the latter from early
April on. For both, there is at least one late March
- Some White-crowned Sparrow migration can usually be
detected in late April and early May. Search
flocks of White-crowned Sparrows for a
Harris's Sparrow, a choice find in the East in this late
April/early May period.
- Rusty Blackbirds can normally be found most of the
month, although numbers drop in late April.
- Orioles (especially Orchard) and Scarlet Tanagers
begin appearing late in the month; the majority arrive in
early to mid-May.
- April, especially the last half, provides the
best chance during the year to spot a Purple Finch (or
even a Pine Siskin or Evening Grosbeak). Search treetops,
like tulip trees whose seeds are favored, or scan flocks
of American Goldfinches. Purple Finches may show up
briefly at feeders, but are unlikely to be seen with
large flocks of House Finches.