Species Survey Strategy - Secretive Sedge Meadow Specialists

Three secretive resident birds can be found across northern sedge meadows in the state’s northern tier counties and include the Yellow Rail, Le Conte’s Sparrow, and Nelson’s Sparrow. All are at the southern or southeastern limits of their continental range in Wisconsin and generally reside in low densities, making them highly-sought after among birders. Each is a state Species of Greatest Conservation Need (SGCN) with Yellow Rail listed as state Threatened and the others as Special Concern. These secretive species largely call during nighttime hours or around sunset/sunrise and require some specialized survey efforts. The Atlas will play a key role in understanding the current status of these priority species. This document outlines tips and strategies to improve your chances of finding them.

Yellow Rail

Yellow Rail by Dominic Sherony

Many Wisconsin birders have never heard the mechanical clicking of this uncommon breeder because they are restricted to large, remote wet meadows and only call during the middle of the night. They should be searched for in any block in the northern two-thirds of the state where large (>40 ha) sedge meadows, open bogs, or shallow marshes are present. Because of their strict nocturnal nature, surveys should be conducted between 2200 and 0300 hours from 15 May to 30 June.

Region: Northern two-thirds of Wisconsin. The WBBA I map underestimates their total range; their likely range is much closer to known occurrences in the Natural Heritage Inventory database. eBird Range Map

WBBA I Range Map for Yellow Rail

Time of Year: Yellow Rails arrive in Wisconsin in late-April to mid-May with the majority arriving in May. Courtship and nesting is initiated by late-May as nests with eggs have been documented from late-May to late-June when peak calling activity occurs. Breeding codes may be recorded into late-August when the fall migration begins and runs into early-October.

Breeding Guideline Bar Chart: (Full chart is on atlas handbook webpage)

Time of Day: Yellow Rails are strictly nocturnal callers, the best time to target calling is well after civil twilight and throughout the nighttime (2200 – 0300 hours).

Focal Habitat: The best habitat areas are large wet meadows or open bogs characterized by “wiregrass” sedges (woolly sedge, few seeded sedge) with little or no shrubs. Canada bluejoint grass is also a common species in these sedge meadow habitats. In central Wisconsin, where the species is also found, habitats here are referred to as poor fen with narrow-leaved sedge meadow associates along with acid-bog plants. Standing water (<18”) and a “quaking or floating” mat are typically present in these habitats with somewhat higher and drier conditions present at the nest site.

Special Methods: Nocturnal surveys are a must for detecting calling males. Some research has indicated little or no moonlight may increase detections. Playback surveys can increase your chances of detecting birds. When a broadcast caller is not available, tapping two pebbles together can mimic a calling male and elicit a response. Surveys from a road edge or along dike roads adjacent to large wetland habitats are a preferred listening and broadcast call location to reduce the likelihood of trampling nests and due to safety concerns.

Code Guidance: Use S for Yellow Rail “clicking” vocalizations during the breeding season (see breeding guidelines bar chart) and when heard in a meadow early in the breeding season but not relocated on subsequent visit. Use H if observed only in suitable nesting habitat during its breeding season. Due to their secretive nature, S7 may be your best chance for getting this species upgraded to probable.

Other Species: Additional rail species like the Sora and Virginia Rail can be heard in these habitats. Surveys targeting Yellow Rail are also beneficial for recording several uncommon sparrow species that also sing at night like Henslow’s, Le Conte’s, and Nelson’s Sparrows. Eastern Whip-poor-wills and American Bittern are also commonly heard during these surveys.

Confusing Species: Very few birds sing at this time of night and even fewer have songs that sound similar to the clicking of a Yellow Rail. Frogs however, are actively calling and some can sound similar. In northern Wisconsin where most Yellow Rails occur in the state, they often co-occur with mink frogs that have a somewhat similar sounding click, often described as horses’ hooves trotting on a cobblestone street. In southern Wisconsin, the Blanchard’s cricket frog, though exceedingly rare, also makes a similar, but faster, clicking or rattling sound, described as shaking a handful of marbles in your hand or two ball bearings clicking together.

More Information on Yellow Rail:

Wisconsin All-Bird Plan
All About Birds
Birds of North America Account (subscription required)

Nelson’s Sparrow

Nelson’s Sparrow by Tom Prestby

This sparrow is exceedingly rare in Wisconsin, as the state lies at the southeast corner of the interior subspecies’ range. They should be searched for in any block in the farthest northwestern tier of counties of the state where large sedge meadows or shallow marshes are present. The species is one of the latest-arriving sparrows in the state, not arriving until late April and throughout May. Due to the paucity of known locations for this species in Wisconsin, additional records from other large sedge meadows in northwestern Wisconsin during WBBA II, would be significant finds for this extremely rare breeder.

Region: Extreme northwestern tier of counties in Wisconsin. The disjunct population in Iron and Vilas counties belies the high potential for new populations to be located between these and the populations in Burnett County.  eBird Range Map

WBBA I Range Map for Nelson’s Sparrow

Time of Year: Nelson’s Sparrow arrives in Wisconsin in late-April to late-May, and appears to be a rare spring migrant and an even rarer to absent fall migrant. Courtship and nesting is initiated by late-May through July. Breeding codes may be recorded into mid-September when the fall migration begins and runs into mid-October.

Breeding Guideline Bar Chart: (Full chart is on atlas handbook webpage)

Time of Day: Dawn and dusk surveys are a good time to detect this species. This sparrow reliably calls at dusk and after sunset and is often detected in late-May and June during nocturnal surveys for marsh birds.

Focal Habitat: The best habitat areas are large wet sedge meadows and edges of emergent marshes with large amounts sedges, Canada bluejoint, and spike-rushes surrounding pockets of open water with little shrub cover. Residual herbaceous cover typically includes a dense mat of grasses, sedges, and cattails with nests constructed within the grass or sedge column.

Special Methods: Nocturnal surveys are a good method for detecting calling males. Surveys on calm nights when most other birds are quiet, can be a reliable way to detect this species with its short trill that could be easily overlooked during early morning surveys. Surveys from a road edge or along dike roads adjacent to large wetland habitats are a preferred listening location.

Code Guidance: Because of the species’ secretive nature within difficult to access wetlands, most breeding behavior will revolve around singing males (Code S and S7). Females usually build the nest with materials found within close proximity to the nest site and are solely responsible for feeding young. Carrying food (CF) will likely be the most common confirmed code due to difficulty in accessing preferred wetland habitats.

Other Species: Rail species (Sora, Virginia, and Yellow Rails) are common associates in these habitats when nighttime survey methods are utilized. Wilson’s Snipe, American Bittern, Sedge Wren, and Bobolink are also commonly heard during surveys in these wet meadow habitats.

Confusing Species: The Nelson’s Sparrow’s song is distinctive with an introductory “attack” note, and although unobtrusive, is the best tool for detecting and identifying this bird. Le Conte’s Sparrow also inhabits similar wet meadows and sings both early mornings and nights but has a distinctive song different from the Nelson’s.

More Information on Nelson’s Sparrow:

Wisconsin All-Bird Plan
All About Birds
Birds of North America Account (subscription required)

Le Conte’s Sparrow

Le Conte’s Sparrow by Nick Anich

This sparrow is a Species of Greatest Conservation Need in Wisconsin and was originally thought of as one of the rarest breeding sparrows in the state. However, breeding bird surveys and the first atlas found this species to be more common than originally thought and found further south than suspected. They should be searched for in any block in the northern half of the state where sedge meadows, wet grassland or hayfields, or open bog – muskeg is present.

Region: The species is found primarily north of the tension zone or in the northern half of counties in Wisconsin. Le Conte’s are largely found where northern open peatlands and wet meadow habitat is found throughout the state.  eBird Range Map

WBBA I Range Map for Le Conte’s Sparrow

Time of Year: Le Conte’s Sparrow arrives in Wisconsin in late-April to early-May, and appears to be a rare spring and fall migrant in southern Wisconsin. This may be due to their elusive nature and further complicated by a lack of singing while on fall migration. Courtship and nesting is initiated by late-May through July. Breeding codes may be recorded into mid-August when the fall migration begins and runs through September.

Breeding Guideline Bar Chart: (Full chart is on atlas handbook webpage)

Time of Day: Dawn and dusk surveys are the best time to detect this species. This sparrow can occasionally be heard after sunset and is much less reliably heard during morning surveys after 0800 hours.

Focal Habitat: The best habitat areas are wet sedge meadows, wet hayfields and fallow cool season grasslands, and open bog – muskeg complexes. The species prefers large areas of tall, dense grasses and sedges with very little or no shrub cover present.

Special Methods: Surveys should be closely focused in and around sunset and sunrise. The species sings most reliably around these times and ceases singing about two hours after sunrise. The species is often picked up during nighttime marsh bird surveys. A good strategy would be to arrive an hour early for nocturnal marsh bird surveys to try and detect this species. Surveys on calm nights when most other birds are quiet, can be a reliable way to detect this species’ weak, thin, and high-pitched song that has little carrying power and can be easily overlooked during morning surveys.

Code Guidance: Because of the species secretive nature within difficult to access wetlands and promiscuous nature, most breeding behavior will revolve around singing males (Code S and S7). This will likely be the most common confirmed code (CF) due to difficulty in accessing preferred wetland habitats.

Other Species: Marsh birds (American Bittern, Virginia and Yellow Rail) are common associates in these habitats when nighttime survey methods are utilized. Wilson’s Snipe, Sedge Wren, Savannah Sparrow, Henslow’s Sparrow, and Bobolink are also commonly heard during surveys in these wet meadow or grassland habitats.

Confusing Species: The Le Conte’s Sparrow is most often detected by its song due to its secretive nature and affinity for difficult to access wetlands. Their song can be confused with the Savannah Sparrow, another associate of wet meadows and grasslands, but the Le Conte’s song has a distinctive “tik” beginning and ending note that Savannah Sparrow’s do not.  Henslow’s Sparrow overlaps in grassland habitats throughout the southern portion of the Le Conte’s range.  Henslow’s have a distinctly different song than Le Conte’s however.

More Information on Le Conte’s Sparrow:

Wisconsin All-Bird Plan
All About Birds
Birds of North America Account (subscription required)

Thanks to Rich Staffen for writing this document.