ORDER STRIGIFORMES
FAMILY STRIGIDAE
Western Screech-Owl (Otus kennicottii)
a. A series of hollow whistles on one pitch, separated at first, but running into a tremulo (rhythym of a small ball bouncing to a standstill); sometimes preceded by two prolonged notes (P).
A series of 7-20 soft notes, all on same pitch; starts slowly and speeds up (F).
At a distance, only the final tremulo may be heard (L).
b. A two-syllable, trilled whistle pdddd,pdddddd, the second descending in pitch.
c. Female, reponding to immatures: a single crow-like bark.
A harsh squeaky eekit,eekit (L).
d. Immatures: a nasal wayh,wayh,wayh,wayh, each succeeding note a little lower in pitch; suggests acorn woodpecker.
In calls "a" and "b" above, calls of male are generally lower in pitch than female's.
Great Horned Owl (Bubo virginianus)
Wide variety of sounds.
a. A resonant hooting of 3-8 hoots; males usually 4-5, in this rhythym: hoo,hoo-oo,hoo,hoo; females (lower in pitch) 6-8: hoo,hoo-hoo-hoo,hoo-oo,hoo-oo (P).Most frequent: low hoots, deeper and lower than Barred Owl's (or Spotted Owl's), hoo-hoo-hoooo hoo-hoo; sexes differ in pitch (F).
The hoot of the female is higher pitched and more rapidly uttered (L).
b. Screams (F).
Various howls, screeches, caterwauls, particularly in defense of a territory.
c. Catlike meows (F).
d. Juvenile: a muted squawk.
Spotted Owl (Strix occidentalis)
a. A high-pitched hooting, like the barking of a small dog. Usually in groups of 3, hoo,hoo-hoo, or 4, hoo,who-who,whooo (P).
The last note drawn out and descending in pitch. These are location calls or long-distance contact call, given by both sexes. Female's call slightly higher in pitch.
Variations are infrequent but do occur. The most common variation is the dropping of the first hoot or the adding of another hoot at the end of the sequence (E. Forsman, unpub. casette tape).
This recording is another variation of the location call.
b. A rising inflection of whoo,whoo,hoo,hoo,hoo,hoo-hoot-hoot,hoo-hoot-hoot (length varies), cut off at end or terminated with a descending hoooo.
This call can escalate into a lengthy series of short, cut-off notes uh-uh-uh-uh-uh-uh....
In this sample, a male is heard giving this more agitated series, with the female responding with the coo-weep contact call (call (d) below).
The terminal ow! call or other ending hoots to this barked-hoot series can also be given independently.
c. Call "b" above may escalate to a shrill kre-ick! kre-ick!
d. Call "c" may in turn escalate to a rising whistle, which rises most abruptly at end and cut off sharply; wheee-et! or cooo-weep! Often given repeatedly. This is a contact call, denoting a higher degree of agitation than calls a or b above; often given by female.
In this sample, a female is heard giving the coo-weep call, and a male mate responds with the 4-note location call (call (a) above).
e. A crow-like bark khaw khaw khaw, given by female.
f. Food-begging calls of juvenile fledglings -- a rising hiss sharply cut off. (See call (a) of Barred Owl, below.)
Call "a" is the most commonly heard. Calls "b" and "c" are heard in varying patterns when the birds are agitated or excited.
Barred Owl (Strix varia)
a. Food-begging calls of juvenile fledgling barred owls -- a hiss rising in volume and sharply cut off at end. These calls are identical to those of the northern spotted owl (T. Hamer).
b. Beak-clapping of female adult in nesting area
c. 8-note location call (given by both sexes). Commonly depicted as who-cooks-for-you, who-cooks-for-you-all?
Location call sometimes includes notes with an "ow" variation.
d. Agitation call, a series of 5-6 initial notes ending with two notes, the first highest in pitch of the series and the second descending in pitch; given by both sexes. Example 1, example 2.
e. Mutual interchange calls of adult male and female, usually near the nest site; an extended series of the standard 8-note location call, often given with "ow" notes
f. Contact whistle call (similar to spotted owl's, but more nasal and raspy; however, in some variations, the two species give near-identical contact whistle calls [T. Hamer])
Compare with the Spotted Owl female's contact call.Female Barred Owls also can give whistles with chitterings.
The whistles calls (call f) and food-begging calls (call a) are the most difficult to distinguish between barred owls and spotted owls (T. Hamer).
Northern Saw-Whet Owl (Aegolius acadicus)
a. A mellow whistled note repeated mechanically in endless succession, often 100-130 times per minute: too,too,too, etc. (P).
Notes all on the same pitch; higher-pitched and faster than Northern Pygmy-Owl's (call "a").
b. An upslurred whistle (U).
c. A raspy call like the sound of a saw being sharpened (N).
Northern Pygmy-Owl (Glaucidium gnoma)
a. A single mellow whistle, hoo, repeated every 1-2 seconds (P). Example 1, example 2.
b. A rolling series, ending with 2-3 deliberate notes: too-too-too-too-too-too-too-too-took-too-took (P).
Sounds somewhat gutteral; this series often followed or preceded by single whistle notes, as described in "a" above.
c. Also a thin rattle around the nest (U).
Flammulated Owl (Otus flammeolus)
a. A mellow hoot (or hoo-hoot), low in pitch for so small an owl; repeated steadily at intervals of 2-3 seconds (P).
Repeated for long periods, 40-60 per min (R).
Given by male. Voiced, not whistled as with Northern Pygmy-Owl.
Cadenced series of mellow hoop or hoo-hoop notes at regular intervals or 3-4 seconds (F).
b. A raspy, hair-raising screech.
ORDER CAPRIMULGIFORMES
FAMILY CAPRIMULGIDAE
Common Nighthawk (Chordeiles minor)
a. A nasal peent or pee-ik (P).
25-35 per min (R).
Abrupt, nasal, buzzy, insectlike, loud berrp, strongly accented at beginning and end of note; also described as peent (F) and beesh-ip (L).
b. In aerial display, male dives earthward, then zooms up sharply with a sudden deep whir (P), also referred to as a hollow booming sound (N).
Can give call (a) at same time.
Common Poorwill (Phalaenoptilus nuttallii)
a. Song is a whistled poor-will, with a final ip note audible at close range.
Song is repeated 30-40/min (R).