Warblers call during nocturnal migration, and these flight calls are also heard frequently during the day.
Several species have a short, buzzy flight call. Under ideal conditions some of them can be told apart.
Here are two Blackpoll Warblers foraging in October at Palmyra Cove, NJ.
Another Blackpoll Warbler (Oct, NJ)
Yellow Warbler (Sep, NJ)
(female, July, NJ).
Yellow Warbler (two flight calls by bird in short flight), followed by Common Yellowthroat (a lower, more electric buzz),then another Yellow Warbler call, for comparison (Sep, PA).
The Connecticut Warbler has a very similar call to Yellow and Blackpoll Warblers. I have located a number of Connecticuts on hearing a series of relatively loud, stationary, Blackpoll-like calls low down in vegetation. Other warblers with this type of call (such as Yellow, Magnolia) tend to be more active and higher up. Unlike Mourning Warblers, which rarely use their flight call when perched, Connecticut Warblers call frequently.
This bird was in a willow and gave a long series of chips before this one flight call, then flew down into weeds (Oct, NJ)
Flight calls and chips (bird in top of small tree, flying off at end; with Gray Squirrel gnawing, Oct, PA).
The Bay-breasted Warbler has a similar short buzzy call to the Blackpoll Warbler but it is distinguishable by being less buzzy, more sibilant. This bird was calling from a perch for a couple of minutes, again at Palmyra. (Sep, NJ)
Note how the sonagram is different.
A rising version (Sep, PA).
This Blackburnian Warbler call is similar to the Bay-breasted (female, breeding grounds,Jul,ME)
The following two Blackburnian flight calls, by different birds, are more like Yellow Warbler, showing that there can be some variation in the flight calls.
(female July, ME)
The more finely buzzy flight call of the Magnolia Warbler is usually a slightly longer call, but very similar to Blackpoll/Yellow Warbler (Sep, ME).
The Chestnut-sided Warbler highly modulated flight call is a slightly lower, finer buzz than the others (Aug, PA).
(juveniles in flight, July, ME)
(presumed, nocturnal migrant, Aug, PA)
Worm-eating Warblers give a high, buzzy call that is often doubled (breeding grounds, May, NJ)
The Pine Warbler flight call is a fine buzz that often descends (July, ME).
Flight calls of the waterthrushes are also buzzy but rise and are longer.
Louisiana Waterthrush (on breeding grounds, Apr, NJ)
Northern Waterthrush (Sep, NJ).
Presumed Northern Waterthrush in flight at dawn. Bird not identified by sight but the rising buzz and sonagram are consistent with Northern Waterthrush (Sep, ME).
All vocalizations of the Cape May Warbler are high-pitched, and the fine, buzzy flight call is no exception (Sep, NJ).
The Common Yellowthroat flight call is a distinctive, lower buzz. This foraging bird used the call repeatedly, which is unusual in my experience (Sep, PA).
(nocturnal migrant, Aug, PA)
(nocturnal migrant, Sep, ME)
The American Redstart has a usually distinctive bisyllabic, sibilant flight call. It can be confused with the similar Black-and-white Warbler and Chipping Sparrow flight calls.
(adult male, Aug, NJ).
A bird in flight before dawn (Sep, ME).
Black-and-white Warbler, bird taking flight (May, PA).
Presumed Black-and-white Warbler flight calls just before dawn. There are a couple of lower American Redstart calls mixed in towards the end. The hissing calls are quite similar to the Ovenbird which is even higher (Sep, ME).
This Black-and-white Warbler in a short flight gave a fine level buzz, showing again that flight calls can be variable and that caution should be given to labelling many nocturnal calls (Sep, ME).
The Ovenbird has a piercing, rising call which is a slightly bisyllabic "suitt", higher and clearer than the previous two species.
(male,breeding grounds, May, NJ)
Yellow-rumped Warblers have two commonly used flight calls during the day, the chip and a slightly buzzy, rising call, which is also the nocturnal flight call.
(bird taking flight, Oct, NJ)
The Black-throated Green Warbler also uses its chip call as a flight call during the day. The flight call itself is clear and rising but higher than that of the Yellow-rump (Oct, NJ)
The Tennessee Warbler is another species with a clear, rising flight call, very similar to that of the Black-throated Green (Sep, NJ).
The Nashville Warbler flight call is similar (Sep, NJ).
Mourning Warblers have a lower, buzzier rising flight call. This is a bird that hung around in my backyard for a couple of days in mid-September (Sep, PA).
Presumed nocturnal Mourning Warbler flight call (4.47am, mid-August, PA)
The Palm Warbler flight call is an emphatic seemp and is distinctive on sonagram (bird in flight, Oct, PA).
The Canada Warbler has a flight call that is almost unique among the warblers (Wilson's Warbler is similar, and American Redstart could be confused with it). It sounds more like a slurred chip.
Bird chipping twice then taking flight and giving four flight calls (July, ME).
This male was quite agitated in my backyard, and was using both the chip call and the flight call. Gray Catbird also calling (May, PA)
Wilson's Warbler nocturnal call. This matches well the examples given by Evans and O'Brien (3.31am, May, PA)
Another species with a distinct call (among eastern warblers, although Pine Warbler is slightly descending) is the Northern Parula. The call is descending, recalling some calls of titmice or Field Sparrow.
(birds in flight, Sep, NJ).
(bird in flight, Sep, ME).
The Black-throated Blue Warbler flight call is similar to the tik calls of Northern Cardinals.
(male, Sep, NJ).