LeConte's Sparrow sings most before sunrise and least after it
Thousands of hours of boreal wetland recordings reveal two song types, different daily peaks, and a clear message for survey timing
A sparrow that keeps singing when most people stop listening
LeConte’s Sparrow is one of North America’s least-studied passerines - not because it is uninteresting, but because it is hard to watch. It breeds in remote, wet boreal habitats and often stays low in dense vegetation, meaning most field detections rely on sound rather than sight.
In a new study using passive acoustic monitoring in north-western Ontario, researchers mapped when this species sings across the day and across the breeding season. The results show a strong dawn chorus, a meaningful dusk peak, and regular singing after dark - particularly early in the season - all of which challenges simplistic ideas of this bird as a strictly dawn-focused singer.
Two song types: the familiar buzz and the rarer ‘flight song’
LeConte’s Sparrow’s primary song is the one most often described - a thin introductory note followed by a fine, high, insect-like buzz. But field observers have long mentioned a more elaborate song sometimes given during display flights, often called a “flight song”, even though it has rarely been captured and analysed in detail.
This study pulled flight songs out of a large autonomous recording dataset. The researchers identified songs that contained extra elements in addition to the primary song, matching historical descriptions of flight song structure. These flight songs were consistently less likely to occur than primary songs at every time of day, underlining that they are a real but infrequent part of the repertoire rather than an alternative used all the time.
Dawn is still king - but dusk matters more than expected
Primary song activity was strongest in the dawn chorus, with the highest rates at late dawn - around the period leading up to sunrise and into the immediate morning. Importantly, song rates and the probability of singing were higher at dawn than after sunrise, and morning singing dropped off as the season progressed.
Flight songs showed a different daily rhythm. They were most frequent in the evening or early dusk chorus, rather than at dawn, and peaked at a different time from the primary song. There was no neat “handover” where one song type replaced the other, but the mismatch in peak timing suggests the two song types may be serving different roles in the bird’s daily social and breeding routine.
Confirmed: LeConte’s Sparrow is a regular nocturnal singer
Perhaps the headline result is the confirmation of sustained singing after dark. The recordings show that LeConte’s Sparrows did sing at late dusk and at night, indicating regular nocturnal singing - particularly early in the breeding season. Both primary and flight songs occurred at night, even if overall rates were lower than at dawn and dusk.
For birders and fieldworkers, this is a useful reminder that “quiet marsh” does not always mean “no birds”. For researchers, it raises new questions about what prompts night singing in this species - whether it is linked to mate attraction, territory dynamics, breeding stage, or other social interactions that are simply difficult to observe in dense habitat.
A season that tails off: singing declines as summer advances
Across the recording window from early June into late July and early August, both the probability of singing and the amount of singing generally declined. The decline did not look identical across all periods of the day, but the overall direction was clear - early season was louder, later season quieter.
Primary song remained particularly robust at dawn compared with other periods, while flight song remained consistently rare, with its strongest emphasis around dusk. In practical terms, this seasonal tapering reinforces the importance of timing if you want confident detections rather than hopeful ones.
What this means for surveys - and for birders trying to confirm presence
The study’s most direct recommendation is simple: if you want to confirm LeConte’s Sparrow is present, prioritise early mornings, starting before sunrise, and focus effort in June. Dawn detections are strongest, and the probability of singing in the morning declines with date.
This matters because LeConte’s Sparrow is the sort of species that can be “present but missed” if survey timing is convenient rather than optimal. The findings also show the value of passive acoustic monitoring for capturing rare song types and behaviours - like dusk-biased flight songs and nocturnal singing - that standard daytime visits can easily under-sample.
Why the method matters: recorders reveal what short visits can miss
These results come from autonomous recorders deployed in remote wetlands and programmed to sample key periods across night, dawn, and dusk. That approach allowed the researchers to assemble enough examples of the infrequent flight song to describe its structure, and to quantify when each song type is most likely to occur.
For a species that is secretive, habitat-bound, and hard to follow visually, this kind of dataset does more than add detail - it changes what we think we know. In this case, it shows LeConte’s Sparrow is not only a dawn singer, but a bird with a broader daily soundscape that includes the evening chorus and the dark hours beyond it.
February 2026
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