October 2017

Birding Danehy Park, Cambridge, Massachusetts

Sun, 01 Oct 2017 00:00:00 GMT

Birds at Danehy Park

Lark Sparrow. Photograph by Jeremiah Trimble.

Records show 171 species of birds visiting the park between 2005 and the present (based on 973 eBird checklists). Bird records are primarily from September to December, the season when 70 percent of the checklists were submitted. There are very few breeding bird records, and only 45 checklists were submitted between June and August during the almost 20 years of eBird records. The greatest number of bird species is directly tied to dates before the unmowed grasses are cut, about early to mid-November, after which the numbers of bird species decline. This is especially true at “Sparrow Hill” and the other un-mowed areas, where 18 species of sparrows have been seen, including the locally rare Grasshopper, Le Conte’s, Nelson’s, and Vesper sparrows. Clay-colored, Lark, and Lincoln’s sparrows can almost be considered regular annual visitors. Dickcissel or Blue Grosbeak also might show up in the fall.

Path up Sparrow Hill. Photograph by Karsten E. Hartel.

Other bird groups, from hawks and falcons to a variety of warblers and vireos, also show up, but often not in large numbers. All three local falcons are annual at Danehy, and Peregrine Falcons are often year-round on the apartment towers to the north of the park. Twenty-nine species of wood-warblers have been recorded, including regular Orange-crowned Warblers along with Philadelphia Vireos that turn up in the fall.

Killdeer and Wilson’s Snipe can still be expected, but it is unlikely that the seven other plovers and sandpipers that historically dropped into the wet fields during inclement migration days will be seen there again since most of those soccer fields are now artificial turf.

Due to the open nature of the park, flyover species such as hawks, falcons, gulls, Common Nighthawks, Chimney Swifts, and Common Ravens can be seen passing over the park, often heading to and from Fresh Pond, which is less than ¼ mile away. If you are standing on the open slope of Sparrow Hill early on a fall morning and have good ears, you might hear numbers of wood-warblers flying over or dropping into the taller trees.

Le Conte’s Sparrow. Photograph by Jeremiah Trimble.

Danehy Park is a place where almost anything might drop in or fly over in the fall. Some of the more interesting records include Glossy Ibis, Gray Flycatcher, Ash-throated Flycatcher, Northern Shrike, Blue Grosbeak, Dickcissel, Eastern Meadowlark, and even some winter finches.

Finding Birds in Danehy Park

Walking paths (see map): The primary half-mile birding path (indicated with dots) runs from the Sherman Street parking entrance, along the wetland, around the oval track, and over the top of Sparrow Hill. This route covers most of the better birding areas. The top of Sparrow Hill is 50 feet above sea level and almost 40 feet above much of this part of Cambridge. The perimeter path (indicated with dashes) follows the outer edges of the southern portion of the park and is one mile long.

As noted below in the directions, there are two parking lots. When I lead my autumn morning walks (see posts on Arlington Birds and BBC trip lists), I ask people to park in the Sherman Street lot. This gives immediate access to the maintenance building and restrooms. Each of the major mentioned areas is labeled in capital letters (A-E) on the map.

From the maintenance building, go slightly left and past the tot lot to an overlook (A). This spot is good for a mix of birds, in part because the houses just outside the park here currently have feeders. Continue left along the wetland (B). You can walk on the grass or on the path. Walking on the path allows birding the tops of the tall willows. Continue along the path to an open area with a picnic table (C). Along the way, look over the mowed grass between the path, the wetland, and the taller trees beyond. Also look over the grass leading up to Sparrow Hill (D) and the hillside with small trees and grasses with a fence at the top. The path just beyond the fence on the hill is an optional part of a route from the other side looking down. If desired, walk along the seasonally flooded wooded wetland. You will pass a batting cage and a “hammer throw box” and come to a fence that bisects the area. There is a small wet area between the fence and the dog run that sometimes holds Wilson’s Snipe during spring migration.

Wetland edge looking north. Photograph by Karsten E. Hartel.

Walk past the dog run and the New Street parking area to the wide main road that runs through the park (portable toilets are located here). From here, just uphill from the portable toilets, you may decide either to go left off the main road to a path parallel around the oval track and eventually up and over Sparrow Hill (D) or take the perimeter path by turning right at a small fenced tot lot. The left path attracts sparrows that feed on the path and along its edges. It is best to walk close to the track and not flush the birds. People will often come by and inadvertently flush them, but the birds usually come back to the path. At Sparrow Hill stop and wait at the sharp bend where you can look up and down the path as the birds return. At the top of the hill is a silver-colored bench where you can go down the grass hill and back to the maintenance building. Don’t forget to check the corners of the tall buildings and the light poles for raptors.

If you want to walk more, go back to the start of the perimeter path, which zigs and zags along and around embankments that have scattered tall trees. Various playing fields will be to your left. Beyond the third softball field is a set of stairs that leads to a lower path and a large maintenance building abutting St. Peter’s Field. Turn right at the bottom of the stairs and then left to a small area of taller trees called the Garden Street Glade (E) that you may want to explore. Turn back to continue along the low path back to the maintenance building and the Sherman Street Lot (do not go back up the stairs).

Danehy is an enjoyable before-work birding break if you are in the area. I hope to see what you find on eBird (see references). It is important to document the avian life in these small urban parks.

Directions and Parking

Directions from the west: Take Route 2 East into Cambridge. Bear right on Route 16 (Alewife Parkway), and continue past the Alewife T station, past Fresh Pond Mall, and partially around the traffic circle at Concord Avenue. Stay on Alewife Parkway, go to the next circle, and take the third exit (New Street). Go about ½ mile to the New Street Parking lot.

For Sherman Street use the same directions but take an immediate right off New Street onto Bay State Road that joins Field Street. Take a left on Garden Street, another left onto Walden Street, and another left onto Sherman Street. Go for a quarter mile to the parking lot.

If you are coming from downtown Cambridge, take Massachusetts Avenue West. Turn left on Walden Street and then right onto Sherman Street.

For Park information: Maintenance Office 617-349-4895 or Cambridge Recreation Department 617-349-6200.

References

Anonymous. Undated. Mayor Thomas W. Danehy Park. http://www2.cambridgema.gov/CityOfCambridge_Content/documents/danehy.pdf
eBird. 2012. eBird: An online database of bird distribution and abundance. Cornell Lab of Ornithology, Ithaca, New York. Available online at http://www.eBird.org.
Danehy Park eBird hotspot accessed on July 8, 2017: ebird.org/ebird/hotspot/L452823

Acknowledgements: Thanks to Jason Forbes for giving me the idea to write this. Bob Stymeist offered comments and Jo Hartel read and edited several drafts.

Karsten E. Hartel is from Arlington and was one of the founding members of the Menotomy Bird Club. He leads weekly bird walks at Danehy Park during September and October that have been sponsored by the Menotomy and Brookline Bird clubs for the last several years.

Vagrancy of Selasphorus and Other Western Hummingbirds to New England

Sun, 01 Oct 2017 00:00:00 GMT

Ruby-throated Hummingbird. Photograph © Shawn P. Carey.

Since the December 1909 Charleston record, many more Rufous Hummingbirds have been reported in the East, with an ever-increasing frequency. During the 1930s to 1950s, multiple Rufous Hummingbirds were recorded from Florida. The first New England record was in 1957 in Orono, Maine (Wilson 1990). Today, dozens of Rufous Hummingbirds are reported annually along the eastern Gulf Coast and elsewhere east of the Mississippi River, as far east and north as Nova Scotia. Such reports have recently been recorded at the rate of 25–75 per year (eBird 2017). Furthermore, a minimum of 18 species of hummingbirds now have been documented east of the Mississippi, with many species demonstrating an increasing rate of reports. Massachusetts alone has recorded approximately 50 Rufous Hummingbirds, with about two to five reports per year (eBird 2017, Massachusetts Avian Records Committee 2017). Almost all records pertain to immature birds in the fall, mostly October through December. A potential mechanism explaining the increase in western hummingbird reports in the fall and winter in the eastern United States is the increased of use of hummingbird feeders, which likely leads to increased detection by observers at the feeders (Greig et al. 2017).

The thrill of attracting a rare western hummingbird to your own yard is unparalleled. While the key component to attracting stray hummingbirds is to maintain fresh feeders through December, there are additional strategies to increase your probability of success. We provide a few critical tips for attracting your own hummingbird vagrant:

Locate one or more feeders in an open area where flyover hummingbirds will see the bright red feeders from afar. If possible, hang the feeder from a tall pole high off the ground, which will increase its visibility.

Ruby-throated Hummingbird at feeder. Photograph by Sean McGrath (CC BY 2.0)

The feeders themselves should be bright red. As a side note, the color of the sugar water—one part sugar, four parts water—should be clear and not contain red dye, which over the long term may give hummingbirds liver failure.

Place multiple feeders in as many different areas of the yard as possible. The first author maintains at least five feeders through early December.

Plant late-season nectaring flowers that can attract late-season hummingbirds even without feeders.

Once you have attracted a late-season hummingbird, keep the feeders from freezing by taking them inside at night. Also, at least one of the feeders should be located near a dense conifer where hummingbirds find refuge between feedings in cold weather.

How will you be able to distinguish a western hummingbird species from a Ruby-throated Hummingbird? Perhaps the easiest initial indicator of a western hummingbird is the date of the sighting. Any hummingbird seen after the first week of October, for example on October 10, should be scrutinized carefully. By October 10, almost all Ruby-throated Hummingbirds have departed our region, and small numbers of western hummingbird species have arrived, and continue to arrive. Therefore a hummingbird observed after October 10 more likely might be a western species than a Ruby-throated Hummingbird.

All that being said, non-Ruby-throated Hummingbirds have been documented in Massachusetts during times of the year when Ruby-throated Hummingbirds are still common. It is wise to learn the basic aspects of fall hummingbird identification, which can be some of the most challenging identification conundrums in New England. For example, dull female and immature hummingbirds in the genus Selasphorus, such as Rufous and Calliope (Selasphorus calliope), can appear similar to female Ruby-throated Hummingbirds. In addition, female and immature Black-chinned Hummingbirds (Archilochus alexandri) are nearly identical in plumage to female and immature Ruby-throated Hummingbirds. A basic field guide can offer initial identification tips, and Sheri Williamson’s A Field Guide to Hummingbirds of North America contains advanced identification information (Williamson 2001).

Immature Female Rufous Hummingbird. Photograph by Alan Schmierer.

Our most common vagrant, the Rufous Hummingbird, is well adapted to cool temperatures. Its breeding range extends from coastal Oregon, west into Montana, and north to Alaska, where temperatures regularly dip down to 15–20ºF at night (Healy and Calder 2006). This hummingbird species is capable of surviving subfreezing temperatures by entering into a state of torpor, although it is unlikely to survive an entire New England winter. Many vagrant hummingbirds appear to depart a hosting yard in decent body condition since people often report the hummingbird feeding heavily before last being seen. Heavy feeding is a typical behavior to put on extra fat before a migratory movement (Russell et al. 1994).

Sometimes a hummingbird may not depart and will stay into the winter, likely resulting in an unfortunate fate in New England. For example, in September 1996, a female Rufous Hummingbird appeared in a yard in Agawam, Massachusetts. The hummingbird remained in the yard into November, and discussion ensued on whether to intervene with the fate of the hummingbird. Tom French, Assistant Director of the Natural Heritage and Endangered Species Program at MassWildlife, was contacted, and a one-time-only permit was issued as an experiment to capture the hummingbird and relocate it into a greenhouse for the winter. The bird was released in the spring and, surprisingly, returned for seven consecutive years, each year being captured and moved into the same greenhouse. Since that era, MassWildlife has reviewed this policy, and has explicitly decided not to issue permits for capturing hummingbirds for the purpose of housing them for the winter. It has become clear that at least some of these hummingbirds leave and return on their own accord, and housing each individual likely is interfering unnecessarily. In addition, it is imperative to understand that vagrants lie on an extreme end of a spectrum—often natural selection acts negatively upon these exceptional individuals. We must accept that natural selection has run its course for millions of years without human assistance, and it is in the best interest of the species to allow natural selection to continue instead of humans attempting to decide what we think is best. While it is true that hummingbird feeders are unnatural food sources, these vagrant hummingbirds have arrived in New England independent of the presence of hummingbird feeders. Hummingbird feeders simply allow these vagrants to fuel up before departing the region.

We offer the following guidelines for homeowners fortunate enough to successfully attract a vagrant hummingbird to their feeder. First, we want to ensure that these hummingbirds get documented and banded. As soon as possible after observing a hummingbird after October 10th, or a suspicious-looking hummingbird before October 10th, please report it—with attached photo if possible—to both Sean Williams, the Secretary of the Massachusetts Avian Records Committee at seanbirder@gmail.com and Andrew Vitz, the Massachusetts State Ornithologist, at andrew.vitz@state.ma.us.

In some cases, species identification is only possible if the bird is examined in the hand. In addition, placing a tiny band with a unique number on the bird’s leg provides the opportunity to better understand survival and movements. In the following year, if the banded bird returns to the same location or appears elsewhere, reading the band number is the only way to determine if it is the same individual. There are at least three certified and licensed hummingbird banders who are authorized to capture and band hummingbirds in Massachusetts. They are:

Sue Finnegan, suefinnegan@comcast.net, southeastern Massachusetts
Andrew Vitz, andrew.vitz@state.ma.us, central Massachusetts
Anthony Hill, anhinga13@hotmail.com, western Massachusetts

Hummingbirds can take up to three weeks to gain enough fat stores to allow migration, which often occurs with the passage of weather systems (Carpenter et al. 1993). High quality migratory stopover sites that contain abundant food resources expedite their departure since hummingbirds gain fat more efficiently at high quality sites compared to low quality sites (Russell et al. 1994). Therefore allowing the hummingbird to feed on abundant food resources in order to gain fat may be the best course of action to encourage its departure. However if you would like to take a more proactive approach, we offer the following advice to encourage the departure of a vagrant hummingbird. If the hummingbird has been present for at least three weeks, temporarily remove the feeders just before a cold front moves through the region. We recommend removing the feeders only during the middle of the day. The feeders still should be available in the early morning and late afternoon since these are the most important feeding hours. However, removal of the feeders as a method of encouraging a hummingbird’s departure is an untested hypothesis. The hummingbird may be just as likely to migrate regardless of feeder availability.

Without doubt, western hummingbirds will continue to occur in Massachusetts, and it is our opinion that these guidelines provide the best actions for the birds. Please report your vagrant hummingbird sightings to the authors, and do not hesitate to contact us with specific inquiries about odd hummingbirds in your yard.

Literature Cited

Carpenter, F. L., M. A. Hixon, C. A. Beuchat, R. W. Russell, and D. C. Paton. 1993. Biphasic mass gain in migrant hummingbirds: Body composition changes, torpor, and ecological significance. Ecology 74: 1173–1182.
eBird. 2017. eBird: An online database of bird distribution and abundance [web application]. eBird, Ithaca, New York. Available: www.ebird.org. Accessed July 24, 2017.
Greig, E. I., E. M. Wood, and D. N. Bonter. 2017. Winter range expansion of a hummingbird is associated with urbanization and supplementary feeding. Proceedings of the Royal Society B: Biological Sciences 284: pii: 20170256. doi: 10.1098/rspb.2017.0256.
Healy, S. and W. A. Calder. 2006. Rufous Hummingbird (Selasphorus rufus) in The Birds of North America (P. G. Rodewald, Ed.). Ithaca: Cornell Lab of Ornithology: https://birdsna.org/Species-Account/bna/species/rufhum. Accessed August 9, 2017.
Massachusetts Avian Records Committee. 2017. Database. www.maavianrecords.com/database (accessed August 10, 2017).
Russell, R. W., F. L. Carpenter, M. A. Hixon, and D. C. Paton. 1994. Impact of variation in stopover habitat quality on migrant Rufous Hummingbirds. Conservation Biology 8: 483–490.
Sprunt, A. 1929. The Rufus Hummingbird (Selasphorus rufus) in South Carolina. Auk 46: 237–238.
Williamson, S. 2001. A Field Guide to Hummingbirds of North America. New York: Houghton Mifflin.
Wilson, H. 1990. The autumn migration: 1 August–30 November, 1990. Maine Bird Notes 4: 19–29.

Sean M. Williams grew up in South Boston, where he often visited urban oases as a young birder. Recently he completed his graduate degree from Michigan State University in biology. He has been working for MassWildlife and will be leading field trips to his field sites in Peru.

Andrew C. Vitz is the State Ornithologist for the Massachusetts Division of Fisheries and Wildlife, where he works on a variety of issues related to bird conservation. Before coming to Massachusetts, Andrew worked at the Carnegie Museum of Natural History in Pennsylvania and completed his graduate work at Ohio State University. He lives in Princeton and enjoys local birding at Wachusett Meadow Wildlife Sanctuary and Wachusett Mountain State Reservation.

Nonbreeding Vocal Repertoire of Northern Saw-whet Owls

Sun, 01 Oct 2017 00:00:00 GMT

Habitat

Northern Saw-whet Owls use a wide variety of habitat during winter. While the canonical location of dense pine stands is always a good place to look (Petersen and Meservey 2003), birds in autumn 2016 were found in dry deciduous forests, even-aged stands of white and red pine, and weedy field edges. Surprisingly, up to half of the birds were found in deciduous swamps, including red maple swamps and other areas containing standing water with stunted deciduous shrubbery.

Vocal Array

The vocal array of Northern Saw-whet Owls is surprisingly broad. While many observers are familiar with the male’s standard advertising song of monotonous toots and other sharp cries or whines, many of us—including the author of this work—are unfamiliar with the variety of barks, chirps, chips, squeaks, and chatters these owls make in interaction with one another or in response to other stimuli. The summary below categorizes various sounds, speculates about their possible meaning, provides visual sonograms of the vocalizations, and—in the Bird Observer Online version of this article—also provides recordings by the author, or other recordists as specified, to help readers become familiar with the diversity of sounds. Chances are you have heard some of these while owling and not been aware of what you were hearing. For an excellent descriptions of Northern Saw-whet Owl sounds, please see Cornell’s Birds of North America entry on this species or P. A. Johnsgard’s North American Owls: Biology and Natural History.

Advertising Song

The male Northern Saw-whet Owl sings the familiar and fairly rapid toot toot toot song most frequently from March through May on the breeding grounds. These monotonous toots are similar in pitch to the whinny of an Eastern Screech-Owl, and distinctly different from the chipping sound of an eastern chipmunk. Be aware that the owls can vary the speed or tempo dramatically, and often they will change the volume during a single bout of song. Usually this song will be given from high in the trees, from an extremely well hidden perch. Of the approximately 80 different auditory encounters I had with Saw-whets during the 2016 season, only about 20 involved primary song. Only two of the owls were visible when singing, and I was able to photograph only one.

Figure 1. Sonogram of standard advertising song of the Northern Saw-whet Owl.

This song was recorded on March 10, 2017, at Desert Natural Area, Marlborough, Massachusetts. Click the sonogram to hear the recording. Playback issues? Here's a direct link to this audio clip.

Figure 2. Sonogram of rapid or agitated song of the Saw-whet Owl.

This fast song was recorded on November 23, 2016, Wayne F. MacCallum (formerly Westborough) Wildlife Management Area (WMA), Massachusetts. An Eastern Screech-owl is also singing in clip. Click the sonogram to hear the recording. Playback issues? Here's a direct link to this audio clip.

Cries, Whines, and Shrieks

The most common vocalization of Saw-whet Owls in winter is a sharp cry, wail, whine, or shriek. More than 60% of birds I heard during the winter of 2016–2017 vocalized some form of cry. Often these type of cries will come in bursts of two or three close together, which will sometimes be repeated for several minutes. There is much variation in these sounds, from almost lazy, weak, and soft cries to agitated and extremely loud wails and shrieks. A single cry can often be fairly long in duration—up to a few seconds in length. The owl seems to make this vocalization when annoyed or agitated. It is usually given from a low perch to several meters high in trees. Note that other owls such as Barred, Spotted, Long-eared, and Western Screech sometimes give similar sounds. And perhaps most confusingly, other owls often respond vigorously to these Northern Saw-whet Owl cries, wails, and whines. Here are several examples of Saw-whet cries and wails.

Figure 3. Sonogram of loud wails from Desert Natural Area, Marlborough, Massachusetts, on December 20, 2016. Click the sonogram to hear the recording. Playback issues? Here's a direct link to this audio clip.

Figure 4. Sonogram of soft wails. These softer wails are from Desert Natural Area, Marlborough, Massachusetts, January 2, 2017. Click the sonogram to hear the recording. Playback issues? Here's a direct link to this audio clip.

Figure 5. Sonogram of loud, agitated wails. This wail series is from Mount Hopkins, Arizona, January 6, 2017. A Whiskered Screech-Owl is singing at end of recording. Click the sonogram to hear the recording. Playback issues? Here's a direct link to this audio clip.

Figure 6. Sonogram of single wail and then loud bark sound, recorded at Crane Swamp, Northborough, Massachusetts, December 11, 2016. Click the sonogram to hear the recording. Playback issues? Here's a direct link to this audio clip.

Barks, Chips and Chirps

These less common sounds begin to enter the realm where, upon first hearing or recording them, the response of the author was: “Is that really an owl?” Many of these sounds are surprising and often sound like rodents, insects, or even dogs. The interpretation of these sounds is contact notes and they are often given after birds have flown in to a low perch less than a meter in height to investigate. While recording the sonogram and sound in Figure 8, the author was fortunate enough to see the owl fly in and perch less than three meters away in the base of a small pine.

Soft Barks

A fairly common sound given by Saw-whets is a soft, single, descending bark or a series of these barks. This can vary dramatically from a soft and lazy sound to a series of sharp and agitated barks. The individual barks are short in duration, generally lasting less than half a second. Various references in the literature call this the skiew sound. To the author, it sounds a bit like a small dog or puppy giving soft barks. Or it may be vaguely similar to the sound of tennis shoes squeaking on a gym floor. Saw-whets often give this sound from low perches near the ground.

Figure 7. Sonogram of soft barks recorded by Scott Weidensaul in Pennsylvania, October 26, 2004. This trimmed recording is from Cornell’s Voices of North American Owls. Click the sonogram to hear the recording. Playback issues? Here's a direct link to this audio clip.

Figure 8. Sonogram of a single soft bark, recorded at Desert Natural Area, Marlborough, Massachusetts, February 6, 2017. Click the sonogram hear the recording. Playback issues? Here's a direct link to this audio clip.

Figure 9. Sonogram of a single, fairly sharp bark, recorded at Desert Natural Area, Marlborough, Massachusetts, February 6, 2017. Click the sonogram to hear the recording. Playback issues? Here's a direct link to this audio clip.

Sharper Barks/Chips

Northern Saw-whet Owls also will respond with sharper bark notes, often in a series of two to five. They sound a bit more like chip notes and are shorter in duration than the barks. These are somewhat similar to chipping notes of eastern chipmunks, warblers, or Northern Cardinals, and are generally given from low perches near the ground.

Figure 10. Sonogram of soft song and loud, sharp chips from separate birds, recorded at Desert Natural Area, Marlborough, Massachusetts, December 6, 2016. Click the sonogram to hear the recording. Playback issues? Here's a direct link to this audio clip.

Figure 11. Sonogram of loud chips and squeaks, recorded at Stirrup Brook, Northborough, Massachusetts, December 22, 2016. Click the sonogram to hear the recording. Playback issues? Here's a direct link to this audio clip.

Figure 12. Sonogram of sharp chips, recorded at Desert Natural Area, Marlborough, Massachusetts, February 6, 2017. Click the sonogram to hear the recording. Playback issues? Here's a direct link to this audio clip.

Chatters and Insect-like Buzzing

From the bizarre to the extreme, Saw-whet Owls will occasionally give a dry chatter or buzzing, which, to the author, sounds most like a cricket or grasshopper. It may also recall the twittering of a flock of Chimney Swifts, but considerably drier. This sound can be given in a fairly long series, often several seconds in duration. To the author, this is an extremely unusual sound to expect an owl to make. Similarly, some of the chips described in the previous section when given even shorter and drier may sound insect- or rodent-like. Some sound like sharp and dry eastern chipmunk notes. These sounds also appear to be contact notes, but curiously are often given from higher perches in dense trees than the barks, chirps or squeaks.

Figure 13. Sonogram of dry, insect-like chatter. These cricket-like sounds were recorded at Assabet River NWR, Sudbury, Massachusetts, December 29, 2016. Click the sonogram to hear the recording. Playback issues? Here's a direct link to this audio clip.

Figure 14. Sonogram of dry chirps/chips, recorded at Desert Natural Area, Marlborough, Massachusetts, December 6, 2016. Click the sonogram to hear the recording. Playback issues? Here's a direct link to this audio clip.

Bill Snaps

On rare occasions, at least during winter, Northern Saw-whet Owls will respond with bill snaps. In seven seasons of owling, the author has heard—but never recorded—this sound only twice. The bill snaps most resemble marbles or rocks clicking together, and are given in a short series.

Sound variation

The descriptions and recordings above should be considered but a small sample of the amazing variability displayed by these owls. For each standard response, there are many variations in pitch, duration, urgency, and volume. eBird’s media search feature allows readers to search through a vast array of sounds, including many from Northern Saw-whet Owls. The link to sounds can be accessed at https://ebird.org/media/catalog.

Northern Saw-whet Owls can be common in Massachusetts in the nonbreeding season. While they are hard to locate in their daytime roosts, observers can encounter these birds by searching and listening carefully for the wide array of sounds they make. Go out next fall and winter to your local hot spot and give them a try!

References:

Johnsgard, P. A. 2002. North American Owls: Biology and Natural History, 2nd ed. Washington, D.C.: Smithsonian Institution Press, pp. 234–241.
Petersen, Wayne R. and W. Roger Meservey, ed. 2003. Massachusetts Breeding Bird Atlas, Massachusetts Audubon Society. Amherst, Massachusetts; University of Massachusetts Press, pp. 184–185.
Rasmussen, J. L., S. G. Sealy and R. J. Cannings. 2008. Northern Saw-whet Owl (Aegolius acadicus) in The Birds of North America Online (P. G. Rodewald, Ed.). Ithaca: Cornell Lab of Ornithology: https://birdsna.org/Species-Account/bna/species/nswowl Accessed March 15, 2017.

Tim Spahr runs a scientific consulting company focused on asteroid science. When not working, Tim can be found in and around Worcester County chasing warblers, and Red Crossbills if they are nearby.