59 Henslow's Sparrows: An Up-Date by Madeline J.W. Austen

Introduction Knapton 119821 reported that only In , Henslow's Sparrow 17 individuals in seven widely (Ammodramus henslowiil has been scattered areas across southern known to breed in and in Ontario were detected during the southwestern . In recent 1981 breeding season. In 1983, the years, Henslow's Sparrow has been known Ontario population of known to breed only in Ontario, with Henslow's Sparrows was 25 to 29 the majority of nesting sites in the individuals at 13 sites (Ontario mid-1980s being located in the Breeding Atlas; Risley 19831. southern part of Hastings, Lennox­ During the Atlas of the Breeding Addington, and Frontenac Counties, of Ontario, the Henslow's and in Prince Edward County. It also Sparrow was found in only 38 has occurred in Grey, Bruce, and squares, and in only 8% of these was Dufferin Counties. Figure 1 shows breeding confirmed (Cadman et al. the breeding distribution of 19871. At this time, it was unlikely Henslow's Sparrow in Ontario, based that the total provincial population on data from the Breeding Bird Atlas exceeded 50 pairs in any given year and the Ontario Rare Breeding Bird (Knapton 1987). The ORBBP received Program (ORBBPI. information on only 23 Henslow's This article provides an up-date Sparrow sites, seven of which were on the status of Henslow's Sparrow active during the 1986 to 1991 period. and summarizes the results of survey However, breeding site information efforts since Knapton (19861. from the Kingston area was not reported to the ORBBP. Population trends and status Active colonies reported in in Ontario Ontario Seasonal Summary reports Population declines have been during the summers of 1986 - 1991 reported in Ontario within the last 30 included: Shelburne area (T. Sabol to 40 years, and the species' range and Walpole Island (C. Spitzl in 1986; within the province has also been Shelburne area (T. MurrayI and reduced. Henslow's Sparrow numbers Kortright, Kleinburg (E. Edmundsl in appeared to have decreased in the 1987; three birds in Arkell Hills, late 1970s or early 1980s in Ontario in 1988; and Conn area in (Knapton 1982; Speirs 19851. Declines (fide T. Murrayl(R. have also been noted in the number Weir pers. corom. 19921. of individual HensloW's Sparrows reported during spring migration in Current Status Ontario from 1986-1993: 17, 17, 18, In 1986, Henslow's Sparrow was 0, 3, 5, 7, and 8 (R. Weir, pers. listed as Threatened by the Ontario corom., 1992; R. Ridout, pers. Ministry of Natural Resources. Based corom., 19931. on the ORBBP's review of available

VOLUME 12 NUMBER 2 60

CI) 0c CI) I :2 b w> g' ~ ~ tt '6 , l. Q. et CI) ~ CI) et" o. m~ •

Figure 1: 10-km squares in which the Henslow's Sparrow was reported to the Breeding Bird Atlas and the Ontario Rare Breeding Bird Program in .

ONTARIO BIRDS AUGUST 1994 61

information on the population trends Lennox-Addington, Leeds-Grenville, and status of Henslow's Sparrow in and Stormont-Dundas-Glengarry Ontario and across North America, Counties. Eighteen former Henslow's the Committee on the Status of Sparrow sites were visited in 1992, Endangered Wildlife in Canada but no Henslow's Sparrows were lCOSEWIC) designated the Henslow's located. Only three sites lTuttles Hill, Sparrow as Endangered in Canada in Frontenac Co.; Arkell Hill, April, 1993. The species was formally Wellington Co.; and a site west of registered under the Ontario Dundalk, Grey Co.l still had Endangered Species Act in May of that was apparently suitable for the 1994 to give the species and its species. Approximately 150 other habitat legal protection. sites with suitable habitat or potentially suitable habitat were Recent surveys in Ontario checked for Henslow's Sparrows in A thorough survey for Henslow's 1992. One singing male was found in Sparrows had not been conducted in eastern Ontario on June 25 and 26, core breeding areas in Ontario since well into the breeding season. The Knapton 119861. In June of 1988, bird was found in an old hayfield, 1989 and 1990, ORBBP staff and approximately 3 ha in size, that is volunteers surveyed the southern dominated by grasses (0.5 - 1 min portion of Grey County and sections heightL but is beginning to be of for Henslow's invaded by shrubs. Sparrows; two birds were found in In 1993, suitable sites were 1988, one singing male was found in checked for Henslow's Sparrows in 1989, and no birds were found in Prince Edward County, Amherst 1990. Volunteers also surveyed north Island, and Walpole Island by Ridout Wellington for Henslow's Sparrows and Austen (19931. Some historic sites during the ORBBP but no birds were and suitable areas in Haldimand­ located. In 1989, a site with 10 Norfolk and Niagara Regional territories was located in Haldimand­ Municipalities were surveyed by Norfolk Regional Municipality, but volunteers. Two sites near Sarnia the colony was "abandoned lLambton CountYl were also checked mysteriously" during the breeding for Henslow's Sparrows: the Bunyan season lD. McRae, pers. comm.l. location where a pair was present in In 1992 and 1993, surveys for 1984 (Knapton 1984, 1986), and the Henslow's Sparrows were conducted Sarnia Airport where a singing male in various areas of southern and was reported in 1985. In 1993, eastern Ontario using census Henslow's Sparrows were found only techniques similar to Risley (1983) at the site located in eastern Ontario and Knapton (19861. In the summer during the 1992 survey. of 1992, thirty lO-km squares in The results of the 1992 and 1993 which the species occurred during surveys suggest that far fewer than 50 the Atlas were surveyed. Squares pairs (probably less than 10 pairsl are were located in Grey, Wellington, breeding in the province. It is Dufferin, Northumberland, Prince possible that there are other active Edward, Hastings, Frontenac, Henslow's Sparrow sites that remain

VOLUME 12 NUMBER 2 62 undetected, but surveys by Risley Sparrow populations from 1966 to (1983), Knapton (1986), Austen and 1988, with an average rate of decline Kubisz (1992), and Ridout and Austen of 3.5 to 4.5% per year. Results from (1993) all suggest that the Ontario BBS routes in Canada during the population of Henslow's Sparrow is period from 1967 to 1988 suggest a continuing to decline. Clearly, decline in Henslow's Sparrow Henslow's Sparrows are critically numbers, but the species was not imperilled in Ontario and worthy of reported on enough routes to Endangered status. accurately determine a population trend (B. Peterjohn, pers. comm., 1991). The BBS is a roadside survey, Henslow's Sparrow sightings conducted annually in mid-June in A Henslow's Sparrow sighting was road-accessible areas across North reported to Birders Journal in the America. summer of 1992 (location unknown, Henshaw and Kerr 1992), but In the majority of the according to the reporter the site was northeastern and northcentral United abandoned early in the summer. A States where Henslow's Sparrow has Henslow's Sparrow was also reported been listed, the species is considered singing at one of the first ten stops on of Special Concern or Endangered. It the Roblin Breeding Bird Survey is listed as Endangered in route in the Tweed area ou 7 June Massachusetts, New Hampshire, New 1992 (E. Hayakawa, pers. comm., Jersey, , and Virginia 1992). Ron Weir (pers. comm.) (proposed); Threatened in estimated that there were about six Connecticut, Illinois, Indiana, and active Henslow's Sparrow sites in the Iowa; of Special Concern in Kingston area in 1992: two sites in Kentucky, Minnesota, , each of Prince Edv'lard, Lennox­ Maryland, West Virginia, and Addington, and Frontenac counties. Wisconsin; and At Risk in However, no birds were found by Pennsylvania (Hands et al. 1989; ORBBP staff in the Kingston area in Smith 1992). Henslow's Sparrow has 1992, but these surveys were been listed as a "migratory nongame restricted to fields near roadsides. bird of management concern" in the north-central region which includes In 1993, Henslow's Sparrows Illinois, Indiana, Iowa, Michigan, were reported during spring Minnesota, Missouri, Ohio, and migration at Long Point, Point Pelee, Amherst Island, Hockley Valley near Wisconsin (United States Fish and Orangeville (unconfirmed) and Wildlife Service 1987). Butcher (1989) Unionville, but were not known to labelled Henslow's Sparrow as one of breed in these areas. two species of management concern in the United States that are in the Population trends in North most danger of . America and adjacent states Breeding Bird Atlas data from the Breeding Bird Survey (BBS) results northeastern and northcentral United from North America, eastern North States also confirm that Henslow's America, and the United States show Sparrow is a rare breeding bird. Ohio significant declines in Henslow's is the only state listed that has

ONTARIO BIRDS AUGUST 1994 63

Henslow's Sparrows breeding in more Recovery Efforts than 10% of the atlas blocks Although numbers of Henslow's surveyed, with birds reported in Sparrows in Ontario are very low at 18.5% of blocks surveyed. present, there is still potential for the species to recover in the province. There are several active colonies Reasons for decline nearby in Michigan and New York Declines of Henslow's Sparrows in that may act as source populations, the Northcentral and Midwest United and the species is still being seen in States appear to track loss of spring migration at sites such as Long grassland or old field on the Point and Point Pelee. breeding grounds (Knapton 1986; Hands et aI. 1989; McPeek 1991; A national recovery plan for Smith 1992). Reasons for the decline Henslow's Sparrows is being drafted of Henslow's Sparrows in Canada are by M. Austen and the Henslow's unknown, but the loss of suitable Sparrow Recovery Team. The major breeding habitat appears to be the recovery actions recommended for most likely limiting factor. Many of the species include: determination of the abandoned fields in which population status and distribution; Henslow's Sparrows formerly bred determination of the cause of the have succeeded to shrub land or species' decline; determination of the forest, have been subjected to habitat requirements of the species and the availability of that habitat changes in agricultural practices (e.g. during the breeding and wintering rowcrop production, corn planting, seasons; protection and management continual use of fields with no fallow of breeding habitat; and the periods, annual or more frequent development of integrated grassland mowing, overgrazing, pesticide use, etc. J, or have been lost to industrial management programs. and urban expansion. Recovery activities will be Some sites still have apparently concentrated in Ontario. Although suitable habitat for Henslow's there are historical records for the Sparrows, but birds are no longer species in Quebec, the species has not breeding there. For example, in Grey been reported breeding in the County large areas (20-30 hal of province since 1968 (Knapton 1986) apparently suitable habitat still exist and is not recorded on Quebec's list but no birds were found breeding in of rare and threatened species. Due the southern part of the county in to the small size of the population in 1990. Similar situations occur in other Ontario and the limited success of counties such as Prince Edward recent survey efforts, emphasis will Lennox-Addington, and Fronten~c. now be placed on establishing and This suggests that other factors (e.g. managing a network of grassland loss of wintering habitat, mortality areas suitable for Henslow's Sparrows between breeding seasons, or and other grassland species. population losses due to small numbers of individuals in isolated Integrated Grassland Management locations) are also influencing the In the United States and Canada, Henslow's Sparrow population. efforts are being made to protect

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major grassland remnants in national tall grass prairie community (Knapton parks, national grasslands, wildlife 1982). However, with the loss or refuges and nature reserves. The alteration of many grassland and protection of large grasslands appears prairie habitats in North America this to have helped maintain some species often inhabits pasture land Henslow's Sparrow populations in and hayfields (Knapton 1982; Hands Iowa IDrilling 1985 in Smith 1992), et al. 1989). Illinois IHerkert 1991) and Kansas In Ontario, Henslow's Sparrows IZimmerman 1988). Similar efforts occupy fairly specific habitats which which maintain open, grassy fields in often include a high percent, and a agricultural areas or protect and moderate to high density, of grass restore remnant tall grass prairie and cover; a thick mat of ground cover grassland habitats must be from previous years' vegetation (i.e. undertaken in Ontario. This will no gross disturbance to the vegetation necessitate active management in for a period of at least one year); a some areas (e.g. grazing, mowing, or height of dense vegetation of about prescribed burns) to maintain and half a metre; no current disturbance enhance populations of grassland in the form of grazing livestock; and species, including Henslow's a low-lying wet area IKnapton 1982, Sparrow. 1984, 1986; Peterson 1983; Risley This year, funding has been 1983). Colonies have been located in sought from the Endangered Species abandoned fields, ungrazed or lightly Recovery Fund, Canadian Wildlife grazed pasture, fallow hayfields with Services (Ontario Region), and the high clover and alfalfa content, grassy Ontario Ministry of Natural swales in open rolling farmland, wet Resources to develop guidelines that meadows, or infrequently mowed allow for an integrative management fields with an abundance of dead program for Henslow's Sparrows and stalks from previous years' growth other grassland species. A pilot site ICuddy 1984). Despite this, the management plan will be dr~wn up species will occur in areas with for an area in eastern Haldimand­ marginal habitat or areas that do not Norfolk R.M., and will outline correspond with "typical habitat activities that should be undertaken descriptions" for the species 1M. to benefit grassland species that could Cadman, pers comm.). potentially breed in the area (e.g. The minimum area required by Short-eared Owl, Barn Owl, Northern Henslow's Sparrows for breeding is Harrier, Grasshopper Sparrow and estimated at 30 ha IPeterson 1983; Henslow's Sparrow). Ideally, a Zimmerman 1988), but minimum network of protected grassland areas area requirements are far from would be established in the province proven and may not hold for all for the benefit of grassland flora and regions. In Illinois, Henslow's fauna. Sparrows have been documented as being more sensitive to habitat How to locate Henslow's Sparrows fragmentation than other grassland 1. Identify areas with suitable habitat. species including Upland Sandpiper, Henslow's Sparrow is believed to Savannah Sparrow, Bobolink, have originally been adapted to the Grasshopper Sparrow, Sedge Wren,

ONTARIO BIRDS AUGUST 1994 65

Eastern Meadowlark, and Dickcissel of Canada, and the Ontario Field IHerkert 1991). Ornithologists. 2. Learn the "song". Special thanks are also extended Henslow's Sparrows have a very to the volunteers who contributed short, -like song I"tslick") that information during the ORBBP and can be difficult to hear at a distance recent Henslow's Sparrow surveys: when other grassland birds 1e.g. A. Altiman, G. Bellerby, A. Bernier, Bobolinks, Eastern Meadowlarks, D. Bland, M. Cunningham, R. Curry, Savannah Sparrows, etc.) are singing. B. and J. Farnan, B. Gibson, Therefore, it is often best to listen for B. Henshaw, M. Jacklin, R. Knapton, the species' song later in the evening T. McDonald, J. Miles, R. Nisbet, when other bird species have stopped D. Rainer, M. Richardson, singing. On calm nights, Henslow's T. Sprague, R. Weir, the Kingston Sparrows can be heard from 200 m or Field Naturalists, and the Walpole more (Risley 1983). At a site in New Island Heritage Centre INin-da-waab­ York, a singing male was heard from jig). a distance of 240 m in a field Thanks to the Endangered Species occupied by singing Bobolinks, Recovery Fund (World Wildlife Fund, Grasshopper Sparrows and Savannah Canadian Wildlife Service), Canadian Sparrows on a calm night. Wildlife Service 10ntario Region), Henslow's Sparrows may be and the Ontario Ministry of Natural found in association with other Resources for funding Henslow's grassland or wet meadow species Sparrow surveys in the province. such as Northern Harrier, Ring­ R. Ridout and R. Knapton kindly necked Pheasant, Common Snipe, reviewed an earlier draft of the Upland Sandpiper, Sedge Wren, manuscript. Bobolink, Homed Lark, , Vesper Sparrow, Grasshopper Sparrow, Swamp Sparrow, and Savannah Sparrow. Literature cited Austen, M. and M. Kubis~. 1992. Report on a 1992 survey of Henslow's Sparrows in Aclmowledgements Ontario. Prepared by the Federation of Ontario Naturalists, Ontario Rare Breeding The information presented above was Bird Program, for the Endangered Species gathered through the efforts of many Recovery Fund and Canadian Wildlife individuals and organizations. Thanks Service. are extended to R. Guthrie Butcher, G. 1989. Bird conservation: establishing 11991/1992), M. Kubisz 11992), and priorities. Birdscope 3: 1-5. R. Ridout 11993) who helped with Cadman, M.D., P.P.]. Eagles,and P.M. surveys during the ORBBP, and to Helleiner (Compilers). 1987. Atlas of the A. Page who prepared the Breeding Birds of Ontario. University of distribution map. The ORBBP is a co­ Waterloo Press, Waterloo. Ontario. operative program sponsored by the Cuddy, D. 1984. Henslow's Sparrow: Guideline for population monitoring and habitat Federation of Ontario Naturalists and management in Ontario. Report prepared for cosponsored by the Long Point Bird Ontario Ministry of Natural Resources, Observatory, the Nature Conservancy Wildlife Branch, .

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Hands, H.M., R.D. Drobney, and M.R. Ryan. Peterson, A. 1983. Observations on habitat 1989. Status of the Henslow's Sparrow in the selection by Henslow's Sparrow in Broome Northcentral United States. Prepared for the County, New York. The Kingbird 33: 155-164. United States Fish and Wildlife Service, Ridout, R. and M. Austen. 1993. Report on the Twin Cities, Minnesota. 1993 Henslow's Sparrow survey conducted Henshaw, B. and H. Kerr. 1992. Ontario in Prince Edward County and Walpole round-up: April and May 1992. Birders Island, . Prepared by the Journal 1: 215-227. Federation of Ontario Naturalists, Ontario Herkert, ].R. 1991. An ecological study of the Rare Breeding Bird Program, for the breeding birds of grassland habitats within Endangered Species Recovery Fund and lllinois. PhD thesis, University of Illinois Canadian Wildlife Service. at Urbana-Champaign, Urbana, Illinois. Risley, C.]. 1983. Results of a survey for Knapton, R. W. 1982. The Henslow's Sparrow Henslow's Sparrows in Ontario in 1983. (Ammodramus henslowiil in Canada: a status Report prepared for the Ontario Ministry of report. Unpublished Report, Nongame Natural Resources, Wildlife Branch, Toronto. Program, Wildlife Branch, Ontario Ministry Smith, C.R. 1992. Henslow's Sparrow of Natural Resources, Toronto. (Ammodramus henslowii) Pp. 315-330 in K.J. Schneider and D.M. Pence (Editors). Knapton, R. W. 1984. A search for Henslow's Migratory Nongame Birds of Management Sparrows in the breeding season in the Central and Southwestern Regions, Ontario. 'Concern in the Northeast. United States Unpublished report prepared for Ontario Fish and Wildlife Service, Region 5, Newton Ministry of Natural Resources, Wildlife Corner, Massachusetts. Branch, Toronto. Speirs,. ].M. 1985. Birds of Ontario, Volume 2. Knapton, R. W. 1986. A search for Henslow's Natural Heritage/Natural History Press, Sparrows during the 1986 nesting season in Toronto. the Eastern, Central and Southwestern United States Fish and Wildlife Service. 1987. Regions of Ontario. Prepared for Ontario Migratory Nongame Birds of Management Ministry of Natural Resources, Wildlife Concern in the United States: The 1987 List. Branch, Toronto. Office of Migratory Bird Management, United Knapton, R. W. 1987. Henslow's Sparrow. States Fish and Wildlife Service, Washington, pp. 452-453 in M.D. Cadman, P.F.J. Eagles, D.C. and F.M. Helleiner (Compilers). Atlas of the Zimmerman, ].L. 1988. Breeding season habitat Breeding Birds of Ontario. University of selection by the Henslow's Sparrow Waterloo Press, Waterloo, Ontario. (Ammodramus henslowii) in Kansas. Wilson McPeek, G. 1991. Henslow's Sparrow. Bulletin 100: 17-24. pp. 478-479 in R. Brewer, G.A. McPeek, and R.J. Adams, Jr. (Editors). The Atlas of Breeding Birds of Michigan. Michigan State University Press, East Lansing, Michigan.

Madeline J.W. Austen, c/o Long Point Bird Observatory, Box 160, Port Rowan, Ontario NOE 1MO

ONTARIO BIRDS AUGUST 1994