Gnatcatchers and Gnatwrens

Blue-gray Gnatcatcher

Polioptila caerulea
After everybody else attending a 6 May 1992 field trip to Mendon Ponds Park had left, June Feder stayed behind to eat lunch, then drove slowly up a road past a swampy area. When she heard a few “chirps” coming from a wooded area, she parked and walked in.“My attention was drawn to a Blue-gray Gnatcatcher that kept coming back to a small webworm nest in the crotch of a tree, and stabbing its bill into the nest. I assumed it was eating the worms, but soon realized that it was gathering silk and repeatedly carrying it off in the same SW direction.”She walked in that direction, and spotted a pair “working on their cupped nest, fastened astride a lichen-covered stub of a branch on an old willow tree. The nest was covered with the same lichens, and exactly matched the branch, so I never could have detected it had the birds not been in it.” “Call it ‘instinct’ if you will, but I’ll never understand how those tiny birds with only beaks for tools are capable of building such complex, beautifully camouflaged nests.” (GOS, June 1992)
Background
“Finding the sprightly Blue-gray Gnatcatcher . . . is one of the delights of spring birding,” Gordon Meade observed. (Andrle, p. 314) These feisty insect eaters hold their neat, cup-like nests together with spider webbing and decorate them with lichens, placing them in moist, wooded habitats, often near edges, across most of the eastern and much of the western U.S. Migrants may “leap over” over resident birds in Mexico and Central America to reach wintering grounds farther south. Numbers have increased during the last 25-30 years, expanding northward most dramatically in the northeastern U.S. and southeastern Canada, notes Walter G. Ellison in his profile of this species for The Birds of North America series. Occasional “massive northward displacement” can occur under favorable migratory conditions in the spring, which helped it expand its range in 1947 (see below). “Other major northward displacements of migrants occurred in 1954, 1956, 1963 and in several years in the early 1970s.” (BNA 23: 1-3, 16)
Local history
In the early 1900s, this species could be found in Michigan and Ontario, and in southwest Pennsylvania and southern New Jersey, but it was only an irregular, uncommon visitor in New York, Eaton (1914) observed. He listed it as a rare summer resident in Monroe County, with no indication of occurrence in Livingston or Wayne. It had been seen at Rochester on 10 May 1891, on 30 April 1892, on 3 May 1903 and 7 May 1905. (Eaton II: 513, I: county charts) E.H. Short reported finding a nest with four eggs in an oak tree near Coldwater, Monroe County in June 1890. The young were successfully raised. (B&M, p. 347) Horsey, in his checklist of Rochester and Monroe County birds observed from 1913-1936, considered this a rare species. He reported “two nests started but both disappeared” at Cobbs Hill in 1920 and only one other sighting, on 10 May 1935. (Horsey; WBR, 16 May 1949) Starting in the 1940s, Bull believed, populations moved north from New Jersey and east from Ohio and southern Ontario along the shores of Lake Erie – especially after three big flight years in 1947, 1954 and 1963. (Bull, p. 439) Ellison concurs: “Beginning with a major flight in 1947, it expanded northeastward and established regular nesting populations in eastern Pennsylvania and northern New Jersey in 1947.” It then became widespread along the Lake Ontario lowlands in upstate New York from 1948-1951. (BNA 23: 15-16) Interestingly, this is precisely when Allan Klonick made specific note of this species’ apparent increase, in his May 1948 field notes. “Of particular interest to those who have watched the increase of the Cardinal in this area is the similar increase in the occurrence of the Blue-gray Gnatcatcher in the past few years. They were seen at least 5 times during the month and as many as 5 were observed on a single occasion.” (GOS, May/July 1948) The accompanying list of May noteworthies included four on 9 May (Raetz, Barlow) in the “West Rush woods” and five on 15 May (Davis) at Ellison Park.When Leo Tanghe summarized the sightings from 1,665 outings by Genesee Ornithological Society members from 1951-1954, this species was reported 52 times, with all but eight of the records occurring last half of April through the first three weeks of May. (KB 5: 69: 5A-5B)Edson reported that a pair was observed building a nest along Black Creek in the mid 1940s. (WBR, 5 May 1947) “Partially successful nesting” occurred in 1948 at Reed Road Sanctuary, followed by discovery of a nest there the following year. (GOS, August-October 1949; April/May 1950) By 1952 it “now seems probable that it is an established Summer resident in the county,” Edson noted. (WBR, 12 May 1952) It was still considered a rare breeder by Tanghe in his 1953 list of nesting birds in the Rochester area (GOS, May/August 1953), specifically at Reed Road and Scottsville, and “even in the early 1960s, this bird was somewhat scarce,” Fox notes in The Birds of Livingston County, New York. (Fox, p. 73)Now this species is solidly entrenched as a breeding species in our region.
Status
The Monroe County annotated list (1985) described this as a regular, fairly common summer resident.Livingston County, Fox (1998) considered this a (presumably regular fairly common) spring and fall transient and a regular fairly common (formerly rare) summer resident.
Occurrence
Spring: The Monroe County annotated list (1985) indicated a range of arrival dates from 8 April (1982) to 12 May, with a mid range, or “normal arrival time” of 21 April to 8 May. Subsequently, one on 31 March 1999 (R. Spahn) at Island Cottage (GNR) set a new record early date. Spring maxima: 14 on 26 April 1979 (M. Carlson, Perrigo) at Braddock Bay. (LG, May 1979) 15 on 9 May 1964 (Genesee Ornithological Society trip) along lakeshore. (KB 14:162) 10 on 12 May 1956 (Listman, McKinney) at Braddock Bay. (GOS, January-June 1956) 10 on 15 May 1960 (Haller) in the Avon area. (GOS, March-July 1960) 15 on 20 May 1984 (D. Rice, R. Spahn) many locations. (GOS, July/August 1984)
Summer/breeding status: Members of a Genesee Ornithological Society field trip to Taylor Marsh saw a pair nesting in the same tree as a pair of Scarlet Tanagers, indeed only a few feet apart. They “seemed to engage in an incessant territorial dispute.” (BA, 12 June 1969)By 1979 this species was “widely reported as a successful breeder, often in close association with Yellow-throated Vireo and Cerulean Warbler.” (KB29: 217) Spahn found six pair feeding their young along a quarter-mile section of trail at the south end of Canadice Lake in July 1982. (KB 32:273) Results of the first BBA project indicated this species was safely established here, with evidence of breeding found in about a third of the blocks assigned to our region. Results of the second project 20 years later were very similar, suggesting this species has pretty much filled its niche in our region.A similar pattern was found statewide, with both projects finding this species primarily in the main valleys of the Hudson, Susquehanna and Genesee rivers, branching into the Mohawk and Lake Champlain valleys, especially in “densely foliaged trees along watercourses and timbered swamps,” Meade noted, where it often nests “in (the) tops of the tallest trees.” (Andrle, p. 314)

Many local birders encounter this feisty, pugnacious little songster at Island Cottage Wood, where the thin nasal spee call of the parents may lead one within view of its tiny, cup-shaped nest high overhead, “beautifully crafted” of lichen and woven with caterpillars’ silk and spider webs.
Summer maxima: 18+ on 17 July 1982 (R. Spahn) Canadice Lake. (GOS, September 1982) 11 popped out to investigate on 5 August 1977 (F. and R. Dobson), when birders played a screech owl tape along a stretch of roadside woods in Murray. (KB27: 218) Fall: The Monroe County annotated list (1985) indicated a range of departure dates from 11 August to 28 November, with a mid range, or “normal departure time” of 1 September to 5 October. A 28 November bird was traveling with chickadees in Durand-Eastman Park (Davids) in 1982. (KB33: 52)
Winter: Two were at Point Breeze (Davids, Listman) until 1 December 1988. (KB 39:40; GOS, January 1989)

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