99 The Status and Distribution ofthe Prairie Warbler in by Anne B. Lambert and Roy B.H. Smith

The Prairie Warbler (Dendroica islands), where over one hundred discolor) has been considered a have been recorded. There are also relatively rare breeding species in three fall records from Newfoundland Ontario, but one whose exact In Ontario, the Prairie Warbler status was rather poorly known. was first recorded in 1900 (Samuel This led the Nongame Program of 1900; Ames 1901) and was first the Ontario Ministry of Natural proved to breed in the province in Resources to commission a study 1922 (Harrington 1922). Histor­ of its status in , and early ically, breeding has been in 1984 a report was prepared confirmed in ten Counties/ (Lambert and Smith 1984). The Districts (Lambton, Haldimand­ Status Report detailed information Norfolk, Waterloo, Dufferin, available up to 1983, based on the Bruce, Simcoe, Muskoka, Parry literature and communications Sound, Peterborough, Frontenac) with knowledgeable birders, while and suspected in six more this paper summarizes those data. (Middlesex, Manitoulin, Hastings, Additional information obtained Prince Edward, Leeds and during the 1984 season has also Grenville, Lanark). Presently, been included, when available. however, breeding occurs on a regular basis in only six Counties Overview or Districts (Lambton, Simcoe, In Canada, the Prairie Warbler Muskoka, Parry Sound, Peterbor­ has been reported in five provinces ough, and Frontenac). The main but has been proved to breed only stronghold ofthe Ontario in Ontario. It is a very rare spring population is concentrated along migrant in Quebec (7 or 8 the eastern shore of records), and a rare but regular fall in the Districts ofMuskoka and migrant in New Brunswick and Parry Sound, with smaller Nova Scotia (mainly on offshore numbers in Frontenac and

Anne B. Lambert and Roy B.H. Smith, Box 222, Port Rowan, Ontario NOE IMO VOLUME 2 NUMBER 3 100

: Georgian Bay breeding range • other regular breeding sites (current) • isolated breeding record • possible breeding sites o former breeding sites

Figure 1. Breeding distribution of the Prairie Warbler in Ontario: 1900-1984.

Peterborough (Fig. 1). In these is typically dominated by mature areas the population appears to be but stunted white pine (Pinus

stablef although a slight increase strobus), white and red oak may have occurred in Frontenac. (Quercus alba, Q. rubra), and by However, in Simcoe and Lambton patches ofcommon juniper Counties substantial declines have (Juniperus communis var. depres­ been documented. sa). Prairie Warblers most frequently select these low junipers Breeding Habitats for nest sites (Lord 1955; D.A. At least three distinct habitat types Sutherland, pers. comm.). Recent­ have been occupied in Ontario, all ly, use of a similar habitat along characterized by open, scrubby some hydro line rights-of-way in vegetation and usually zeric Frontenac Co. has also been conditions. The most important reported (RD. Weir, pers. habitat is the pine-oak-juniper comm.). scrub found along the Georgian The second important Ontario Bay shoreline and at scattered ~abitat is a sand dune habitat locations along the southern edge exemplified by the ofthe Canadian Shield (e.g. in dunes at Pinery Provo Park Peterborough and Frontenac (Lambton Co.) and, formerly, at Counties). This open,- rocky Wasaga Beach (Simcoe Co.), once habitat (often only 50% vegetated) the site of a large'colony'. At the

ONTARIO BIRDS DECEMBER 1984 101

Pinery, the 'interdunal meadows' were first recorded at Port Franks frequented by Prairie Warblers in 1915, and during the 1930s at comprise a fairly open habitat with least 26 singing males were noted "scattered mature black oak; low over an 8 km length ofdunes shrubs ofjuniper, fragrant sumac, (Saunders 1934, in litt.). At this wild grape, choke cherry and red density there could have been 50 cedar~alllow, vegetation with pairs or more in the entire area of clumping evident" (T. Crabe, pers. habitat between Ipperwash and comm.). A detailed description of Grand Bend. Indeed, after the this habitat has been provided by Royal Ontario Museum's collect­ Sparling (1965). ing trip to the area in 1935, Snyder In the Turkey Point/St. was said to have described the Williams area (Haldimand-Norfolk Prairie Warblers there as RM.), sandy plains with planted "positively abundant" (J.L. Baillie pines and!or deciduous scrub notes, ex ROM files). However, comprise a third habitat type. cottage development has probably This open, successional habitat contributed to a decline in the typically includes pin cherry population since the 1930s, and (Prunus pensylvanica), sapling within Pinery Provo Park the oaks (Quercus spp.) and other planting of pines on some deciduous species. The plantations secondary and tertiaiy dunes only remain suitable as nesting during the 1950s may have led to habitat for 10 to 20 years (A. some reduction in habitat (J.D. Wormington, pers. comm.), but McCauley, pers. comm.). In recent sequential plantings by the years, increasing visitor pressures Provincial Forestry Station have could also have had some effect provided a virtually continuous (T. Crabe, pers. comm.). supply of habitat since the early In 1969 the population was 1930s. Second growth deciduous estimated at 17-22 males (J. scrub is used much more LameY,fide T. Crabe, pers. frequently within the Prairie comm.), but since then there Warbler's United States range, the appears to have been a slow only other Ontario examples being decline. Figures for some a single case of breeding in intervening years are not available, Waterloo RM. in 1982 and one of but from 1977 onwards the possible breeding in Middlesex numbers of singing males were Co. in 1983. An instance of estimated as follows: 1977 - 10 to possible breeding has also been 20; 1978 - 11 +; 1979 - 7?; 1980­ recorded in old fields regenerating between 4 and 8, probably 6; 1981 to red cedar (Juniperus vir­ - between 6 and 8, probably 8; giniana) in Prince Edward Co. in 1982 - 5+; and 1983 - 5 (T. 1979. Crabe, pers. comm.; J.D. McCauley, pers. comm.). The Detailed Bre~ding Distribution present Pinery population seems to be stable at between 5 and 8 . Prairie Warblers singing males, and the total

VOLUME 2 NUMBER 3 102

population for the entire area that suitable habitat was between Grand Bend and Kettle disappearing (Goodwin and Point has been estimated at 10 Rosche 1971). Although complete pairs (T. Crabe, pers. comm.). counts or censuses were not conducted, the numbers involved Middlesex County. The Prairie were probably quite small. The Warbler has never been proved to highest recorded count of eight breed in Middlesex, but two singing males was made in 1972 summer records in the London (A. Wormington, pers. comm.), area in 1930 and 1931 raised the and the slow decline since that possibility that breeding might time can be attributed to the have occurred (Saunders and Dale increasing maturity of the pine 1933). More recently, a singing plantations. The last year in which male was observed in the'Skunk's singing males (2 or 3) were Misery' area, Mosa Twp. on 1, 4 recorded was 1979 (R.J. Curry, and 14 July 1983, again suggesting pers. comm.; C.J. Risley, pers. the possibility of breeding. This comm.), but in 1984 a pair and an bird was occupying a successional additional singing male were habitat described as a mixture of located by the authors at a site low pines, birch and aspen, near Turkey Point. Although interspersed with clearings (S. breeding was not confirmed, this Connop, pers. comm.). find suggests that the Prairie Warbler may yet persist as a Haldimand-Norfolk Regional breeding species in Haldimand­ Municipality. Published and Norfolk R.M. unpublished records indicate that in the early 1930s a small breeding Waterloo . population was discovered in the There is a single, unprecedented Turkey Point-St. Williams area, in breeding record from 1982, when a pine plantations established by the nest with eggs was found near St. Williams Forestry Station. In Bamberg, Wilmot Twp. by R. 1936 a 'colony' of six males was Pickering (P.F.J. Eagles, pers. reported at Turkey Point by G.W. comm.). The habitat was described North ( Ornithological as "second growth forest with Club records,per ROM files) and nesting Golden-winged Warblers breeding was confirmed on 15 July as well". 1942, when a nest with three young was found in South Walsingham (now Norfolk) Twp. . The single (F. North 1943, in. litt.). A small record concerns a nest with 5 eggs population persisted in the St. found on 11 June 1927 on Williams Forestry Station through Shrigley Creek, Melancthon Twp. the next few decades as phased by Dr. P. Harrington (Ontario plantings kept a supply of suitable Nest Record Scheme - hereafter habitat available for about 50 ONRS). The nest was located in years, but by 1971 it was noted juniper, but it is not known

ONTARIO BIRDS DECEMBER 1984 103 whether appropriate habitat exists comm.) indicates that he located a in this area today. 'colony' of about 8 pairs in St. Edmunds Twp. in 1952. In 1953 . Observations of he found a nest with young, but singing males suggest that breeding there were fewer breeding pairs, may have occurred at the following and in the following years the locations: near Cameron Lake, St. colony continued to decline, fInally Edmunds Twp. in 1905 (Saunders disappearing after 1958. 1906); at Colpoy's Bay, More recently, the late George Albemarle Twp. in 1908 and 1909 North is reported to have seen (Klugh 1909,1910); at McVicar, Prairie Warblers at Miller Lake St. Edmunds Twp. in 1928, 1930 Lindsay Twp. in the 1950s and' and 1934, at Stokes Bay, Eastnor 1960s (J. Miles, pers. comm.), Twp. in 1928, and at Oliphant, while occasional sightings of Amabel Twp. in 1933 (J.L. Baillie singing males have occurred during notes, ex ROM files). Collectively, the years 1975 to 1982 (near Cape these records suggest that small Hurd, St. Edmunds Twp.; Chiefs breeding populations may have Point ; and Red been present along the Bruce Bay, Amabel Twp.). Although Peninsula; but it was not until 1981-1983 Ontario Breeding Bird 1953 that breeding was confIrmed. Atlas fIeldwork has failed to Previously unpublished informa­ provide any records (M. Parker, tion supplied by B. Krug (pers. pers. comm.), areas of ap­ parently suitable habitat still exist, particularly along the western side ofthe peninsula (T. Cheskey, pers. comm.; D.A. Sutherland, pers. comm.). Hence the possibility remains that the occasional pair may yet be found breeding on the Bruce Peninsula.

Manitoulin District. ConfIrmed bree?ing records are lacking, but two Instances of singing males in June and July have indicated the possibility of breeding. In 1970 two singing males were present 'in Bu~e~ Twp., 29 June to 16 July, whIle In 1974 three singing males were noted in suitable habitat at Belanger Bay (Dawson Twp.) on 22 May. However, these birds had moved away by the following week (Goodwin and Rosche 1974' Nicholson 1981). In additio~ to these records on Manitoulin

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Island, there are three spring exact size, this population must records (2 in 1978; 1 in 1979) of have represented the largest and single males elsewhere in the most concentrated group of District. However, these probably breeding Prairie Warblers ever represent'overshooting' spring known in Ontario. migrants, and none have been On 19 June 1922, the first reported during 1981-1983 Atlas Prairie Warbler nest for Canada fieldwork (D. Ferguson, pers. (containing 2 young and a young comm.). cowbird) and three additional nests were found at Wasaga Beach by P. . In 1915 a large Harrington and F.A.E. Starr 'colony' of Prairie Warblers was (Harrington 1922). However, found amongst the sand dunes with following World War I, the colony scattered oaks, pines and juniper declined rapidly as "the extensive bordering Nottawasaga Bay building of summer cottages along (Wasaga Beach). "Upwards of this beach encroached upon its 200 birds" were seen by Dr. P. breeding territory" (Devitt 1967). Harrington (J.L. Baillie notes, ex By 1-933 only a small population ROM files), while in 1919 it was remained in the vicinity of estimated that 150 pairs were Allenwood Beach and by the early occupying the three miles from 1940s this too had disappeared. In Oakview to the mouth of the 1948 Devitt found a remnant Nottawasaga River (Devitt 1967). population of at least five singing In 1921, it was found that the males at the nearby Bluewater birds "were localized and followed Beach, but in a subsequent survey the shoreline for about 15 miles, on 23 June 1967, Devitt failed to never further than 200 yards find any Prairie Warblers. inland" (Harrington 1922), hence Two other breeding sites are there could have been considerably known in Simcoe Co. One is along more than 150 pairs. Whatever its the rocky banks of the Severn

ONTARIO BIRDS DECEMBER 1984 105

River in Matchedash Twp., where "up to a dozen" singing males in June 1938 "many singing males have been observed, were given by were observed from Hydro Glen, Brewer (1972). The north shore of near the entrance of Sparrow Lake McCrae Lake was also identified down to Tea Lake", a distance of as a breeding site (Brewer 1972; 14 km (Devitt 1967). The other is Hanna 1979), while Mills (1981) at Burrows Bay on Gloucester added Go Home Lake to the list of Pool, where Mr. and Mrs. A.G. published Muskoka breeding sites. McVicar (pers. comm.) have In addition, extensive but observed two or three pairs of unpublished personal data, Prairie Warblers annually for the representing a compilation of last 10 or 15 years, and have about 15 years' observations, were found several nests. made available by D.A. Sutherland Another possible breeding site is and D.M. Fraser (pers. comm.). located 2 km west of Lake Based on these data (as opposed to Couchiching in OriIlia Twp., specific counts or censuses), the where W.E. Cattley (pers. comm.) present coastal Muskoka popula­ has found singing male Prairie tion was estimated at around 152 Warblers during the breeding singing males. The birds seem to season. The site is a small area of prefer sites close to water (often on limestone outcropping, and islands, peninsulas and bays), but common juniper is the dominant even in these preferred areas, vegetation. Prairie Warblers are absent from some areas of apparently suitable Muskoka District Municipality. habitat, and there are often gaps The earliest known locations are between individual territories Go Home Bay, where an (D.A. Sutherland, pers. comm.). immature male was collected on 1 In the southern sector of August 1904; Beausoleil Island, Muskoka, the range indicated by where six birds were observed on Sutherland and Fraser extends 12 August 1929 (Dingman 1929, from Honey Harbour and the in litt.); and Honey Harbour, north end ofBeausoleil Island, where two were collected in June north amongst the islands (e.g. 1931. P. Saniford (1933, in litt.) Minnicognashene Island, Maxwell wrote of having seen pairs of Island) to Franceville and Prairie Warblers at Go Home Bay Hangdog Islands, with 51 singing "during the last 20 years", and males being estimated in this J.B. Armstrong confirmed breed­ sector. In the Go Home Bay area, ing there in 1933, 1934 and 1936 which extends from High Rock (D.M. Fraser, pers. comm.). Island north to the Tadenac It was not until 1955, however, Peninsula and as far east as Go that any observations concerning Home Chute, 80 singing males the Georgian Bay population were were estimated. Another two birds published (Lord 1955). Later, the were noted at O'Donnell Point, Gibson River became known as but the only known'inland' sites another possible breeding location, were at Go Home Lake, McCrae and directions to this site, where Lake, Gibson River and Baxter

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Lake (together accounting for Prairie Warblers include Loon another 27 singing males). Island (off Twelve Mile Bay); However, additional birds (about 7 Ouimet Point and Davey Island in singing males) were found in 1984 Killbear Provo Park; Franklin at previously unreported sites on Island; and Oastler Lake (Mills Twelve Mile Bay and near Moon 1981); while RL. Bowles (pers. River in Georgian Bay Twp. (H. comm.) added Crane Lake and the Currie, pers. comm.). area "as far east as Hwy 69 In summary, recent estimates around Lake Joseph". indicate a present population of The status in northern Parry about 167 territorial males in Sound District, Le. northwest of Muskoka D.M. In the Go Home the town of Parry Sound, is still Lake Area, J.B. Falls (pers. poorly known. The most northerly comm.) considered that there had location where breeding has been been a slow decline since the late confirmed is in 10 km square 1950s/early 1960s, but elsewhere 17NA44, located northwest of the population appears to be stable Brooks Landing (M.D. Cadman, (D.A. Suthe~land, pers. comm.). pers. comm.), but there is also a June 1933 record from Frank's . The Bay on Lake Nipissing (Ricker situation in Parry Sound is much and Clarke 1939). Hence it is less well known than in Muskoka, possible that additional fieldwork but breeding populations extend could extend the known range in north to at least Franklin Island this area, perhaps even as far north and possibly as far as Pointe au as the "French River Study Area" Baril. The first record occurred on (between Killarney Provo Park and 6 June. 1918, when W.E. Saunders Lake Nipissing), where Brunton observed 3 singing males at Snug (1979) noted "excellent habitat" Island, northwest ofParry Sound, and felt that the species "should be but most present information on looked for". However, during the species comes from a summer 1984, brief checks of biological study of the Blackstone several areas from Pointe au Baril Harbour-Moon Island Provincial northwards (Bayfield Harbour, Park Reserve (Simpson and Byng Inlet, Key Inlet, French Simpson 1973). This extensive River Station and Pickerel River) area is situated southwest of the yielded negative results (D.A. town ofParry Sound, in Sutherland, pers. comm.). Archipelago Twp., and extends As regards numbers, D.A. from Woods Bay, Moon River Bay Sutherland and D.M. Fraser (pers. and the south end of Moon Island comm.) estimated 37 singing males northwards to include Spider and in southern Parry Sound District, Cowper Lakes. The Simpsons south of a line from Wreck Island found a substantial population of to the southern end of Moon Prairie Warblers in this region, Island. Most were concentrated and identified extensive areas of around Loon Island and the north potential habitat. side of the entrance to Twelve Other known locations for Mile Bay. For the Blackstone

ONTARlO BIRDS DECEMBER 1984 107 Harbour-Moon Island area, Long Lake (near Apsley), Cox Simpson and Simpson (1973) Lake, Coon Lake and Stoplog estimated 200 pairs, but based on Lake (all in Burleigh and the amount of habitat they Anstruther Twp.); and Methuen identified, and extrapolation from Lake, Kashabog Lake and Round known Muskoka areas, we Lake in Belmont and Methuen obtained revised estimates of Twp. (D. Sadler, pers. comm.). between 62 and 162 pairs. In The Long Lake colony is probably areas north ofParry Sound we the best known, and was described arrived at tentative estimates of 53 as thriving in 1964 (Goodwin to 159 pairs, after examining 1964). On 28 June 1979, G. 1:50,000 topographic maps. Carpentier (pers. comm.) counted When the known and estimated 10 singing males there, while other figures are combined, a provisional estimates range from 5 to 15, estimate of somewhere between "depending upon time of year and 150 and 360 pairs is obtained for day" (RD. McRae, pers. comm.). the total Parry Sound population. Specific counts for the other sites Additional fieldwork is essential in are not available, but we have order to refine this estimate. estimated a Peterborough po­ pulation of at least 20 pairs, . The perhaps as high as 40-60. Prairie Warbler does not seem to have been reported from . A possible Peterborough County prior to breeding site exists at Mt. Moriah, 1947, when a nest was found at Elzevir and Grimsthorpe Twp., Kashabog Lake (Burleigh Twp., where a singing male was located ONRS). Since then, however, in June of both 1982 and 1983. breeding sites have been found at These are the only records for

VOLUME 2 NUMBER 3 108

Hastings Co., where suitable some areas (RD. Weir, pers. habitat seems to be very limited comm.). In the northern part ofthe (RD. James, pers. comm.). county, another hydro line site was found near Ompah in 1984 (P. Prince Edward County. Although Taylor, pers. comm.). there are no confirmed breeding In addition to the sites records for the County, in July mentioned above, known localities 1979 singing males were located at now include Devil Lake, Canoe two sites 15 km west of Prince Lake (for directions to this site see Edward Point "Singing occurred Goodwin 1982), Clear Lake, and throughut July with 5 males at one Lake Opinicon (all in Bedford site and at least one male at the Twp.), while smaller numbers have other" and the birds occupied a been found in 10 km squares regenerating field "overgrown with 18UE72 (Gould Lake), 18UE44 small red cedar and, at one site, (Puzzle Lake), and 18UE74 interspersed with aspen" (T. (Fermoy). In total, Weir (pers. Sprague, pers. comm.). It is not comm.) estimated between 35 and certain whether these birds were 50 breeding pairs ofPrairie breeders, non-breeders or failed Warblers in southern Frontenac breeders (RD. McRae, pers. Co. in 1983. When the northern comm.), and the sites were not part ofthe county is included, we occupied in subsequent years. consider that the total Frontenac population could amount to 50-65 . Breeding was pairs, with the possibility of yet first confirmed in 1933 when a more being discovered in remote small colony was found at Cross areas. For example, there may be Lake, Kennebec Twp., by RV. areas of suitable habitat along the Lindsay. Another nest was found Mississippi River (D.A. Suther­ there in 1947 and yet another in land, pers. comm.). 1953 (ONRS), but in the meantime other breeding locations The United Counties of Leeds for Prairie Warbler were being and Grenville. Just two records of discovered in the southern part of singing males suggest the the County (Quilliam 1973). In possibility of breeding. In summer . northern Frontenac, summering 1976 a singing male was present birds were noted near Ompah in throughout May and June at the the 1950s (H.G. Lumsden, pers. Slim Bay Peninsula on Charleston comm.), and a colony was Lake, in Charleston Lake Provo discovered at Mazinaw Lake, Bon Park (Bell 1977). It was not found Echo Provo Park in 1971 in 1978, but in that year one was (Goodwin and Rosche 1971). located at the nearby Killingbeck More recently, 1981-1983 Atlas Lake, where the habitat is fieldwork has yielded further probably marginal (D.A. Suther­ records in the southern part ofthe land, pers. comm.). However, county including the previously there may be other areas of unreported finding that hydro potential habitat in this county and rights-of-way were being utilized in additional fieldwork could still

ONTARIO BIRDS DECEMBER 1984 109

yield new discoveries. Point Pelee a maximum count of four was recorded on 9 May 1953. There are also records ofthree on . The first records 24 April 1977, 11 May 1979, and for this county were obtained 15 May 1980 (A. Wormington, during 1984 Atlas fieldwork, when pers. comm.). 3 or 4 singing males were found Normal spring migration dates along railroad tracks north of at Point Pelee fall between 1 and Christie Lake (P. Taylor, pers. 23 May, with record early and late comm.). The open, rocky, juniper­ dates of 16 April (1982) and 29 type habitat was similar to that May (1979), respectively. These used at other Shield edge locations. dates reflect the pattern throughout , although a few Migrant Records early June dates have been Throughout southern Ontario, the recorded (latest 6 June 1967 at Prairie Warbler is considered to be Hamilton, apart from a 16 June a rare or very rare migrant in both 1969 date at Presqu'ile Provo spring and fall. Most records have Park). The earliest dates of arrival occurred at known concentration on the breeding grounds are 2 May points such as Point Pelee, (1965) at Clear Lake, Frontenac, Rondeau and Long Point on Lake and 5 May (1981) at Beausoleil . Erie, or Presqu'ile and Prince Island, Muskoka, but the average Edward Point on eastern Lake date of arrival on the Frontenac Ontario. The heavily populated breeding grounds (based on 13 areas ofHamilton, Toronto and years' data) is 12 May (Quilliam Durham RM. have also yielded a 1973). number ofrecords. Among these F all dates at Point Pelee range sites Point Pelee is pre-eminent s~ring from 10 August to 20 September, for migrants, and at all sites while elsewhere in Ontario the except Long Point and Durham earliest fall date seems to be 7 RM., spring records greatly August 1977, at Long Point. outnumber those in fall. This is Probably, most have departed by probably because in spring, birds early September (A. Wormington, are easier to locate and there is pers. comm.). The latest more birding activity. In fact, Long documented date is 12 October Point data indicate that similar 1975 at Mississagi Light, numbers are recorded in both Manitoulin (Nicholson 1981), but seasons (averaging 2 per year -in only four October records have recent years). Over the last 20 been located. Full details years, the Long Point Bird concerning these and other migrant Observatory has trapped 2.7 records have been provided in the Prairie Warblers for every 10,000 Status Report (Lambert and Smith warblers (all species) banded, 1984). which provides some measure of the species' rarity as a migrant. Discussion Most records ofmigrants As outlined in the preceding involve single individuals, but at sections, present day breeding

VOLUME 2 NUMBER 3 110

populations of Prairie Warblers in Parry Sound District). However, Ontario are concentrated in areas we believe that the lower estimate ofMuskoka and Parry Sound is more likely: hence in round fringing Georgian Bay, and in figures the Ontario population Peterborough and Frontenac probably does not exceed 500 Counties. Together, these areas pairs. account for over 90 per cent of the Preliminary data from the population. In total, there was in Ontario Breeding Bird Atlas (Fig. 1984 a known Ontario population 2) indicate that the present (1981­ ofbetween 321 and 336 pairs (see 1984) distribution does not differ Table 1), but the figure could greatly from the known historic amount to between 450 and 700 range (Fig. 1), except, possibly, in approximately, if allowance is Bruce Co. To date, Prairie made for those possibly present in Warblers have been reported in poorly known areas (e. g. northern the breeding season from 38 ten

Table 1: Estimated numbers of Prairie Warblers (pairs or singing males) presently breeding in Ontario (data to 1984).

Known as of Estimated Estimated County/District 1983/84 additional total

Lambton 10 - 10 Middlesex - 1 1 Haldimand-Norfolk 1 1 2 Waterloo - 1 1 Bruce - 5 5 Simcoe 3 10 13 Muskoka 167 8 175 Parry Sound 67 85-291 152-358 Peterborough 20 20-40. 40-60 Hastings - 1 1 Prince Edward - - - Frontenac 50-65 10 60-75 Leeds & Grenville - 2 2 Lanark 3 1 4 Manitoulin - 2 2

Total: 321-336 147-373 468-709

ONTARIO BIRDS DECEMBER 1984 111 km squares in Sector 1, with For the most part Prairie confirmed breeding in 7 squares, Warblers in Ontario have utilized and probable and possible natural rather than man-altered breeding in 15 and 16 squares, habitats. Presumably they have respectively. However, a concerted bred for centuries in rocky scrub effort during the last year ofAtlas areas bordering Georgian Bay and fieldwork might relocate the the southern fringe of the species in some former haunts, Canadian Shield and in the dunal including the following 10 km habitats bordering Lake Huron. squares with historic summer Apart from Wasaga Beach and the records but still lacking Atlas Pinery area, significant threats to records: Region 4: 17MT54; these habitats have not been Region 5: 17NT42; Region 8: identified; hence the present 17MA40, 17MA50, 17MA60, situation is one of relative stability 17MV69, 17MV85; Region 9: and security. 17NU59; Region 13: 17NV96, By contrast, man-altered 17PV07, 17PV25; Region 16: environments have been used to a 17QV14, 17QV15, 17QV24, much greater extent in the United 18TE64; Region 18: 17NA60, States (Nolan 1978), and as a 17NA80, 17NV98, 17PV16; consequence there has been a Region 20: 18UD36; Region 25: considerable expansion during this 18UE45; Region 28: 17NA52, century in the U. S. breeding range 17NA81; Region 33: 17LA47. (which includes parts of about 31 Birders are encouraged to check states east of the Great Plains). these areas in 1985. Recent range expansions have

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SECTOR 1

Figure 2: Breeding distribution ofthe Prairie Warbler in Ontario, based on preliminary (1981-1984) data from the Ontario Breeding Bird Atlas. Within 10 km squares: square=confirmed breeding; large circle=probable breeding; small circle=possible breeding.

been noted in several northern compared with many parts ofthe states, such as Ohio, New York, U.S. range. Although data are Vermont, Maine, and possibly lacking, we suspect that this Wisconsin; while in Michigan, reflects a lower productivity, which range expansions in some areas might result from a shorter have been offset by contractions in breeding season, a harsher other areas, hence the overall climate/microclimate, possibly situation remains dynamic (Walk­ greater effects of cowbird inshaw 1959; Payne 1983). Newly parasitism, or other factors. exploited habitats include regen­ While the Prairie Warbler's erating old fields, logged areas, future on its Ontario breeding power line rights-of-way, striJr range seems secure, the situation mined areas and young conifer in the Caribbean wintering areas is plantations. In Ontario, however, more difficult to assess. In winter, these habitats have rarely been Prairie Warblers appear to be used, apart from the three cases most abundant on the Bahamas, mentioned previously. fairly numerous on the Greater In much ofthe Ontario range, Antilles and much less common in habitats that appear suitable seem the Lesser Antilles. However, to be under-utilized, and breeding destruction of the various scrub densities are generally very low forest habitats used by wintering

ONTARIO BIRDS DECEMBER 1984 113 birds is an ongoing process, A. Mills, B. Morin, G. Murphy, particularly in the Greater D. Myren, J. Nicholson, H. Antilles, and its effects on the Ouellet, B. Parker, M. Parker, S. Prairie Warbler are largely Peruniak, J.K. Reynolds, P. unknown. Richter, A. Rider, R Ridout, C.J. In conclusion, the Prairie Risley, P. Ritchie, K. Robinson, Warbler is not endangered, D. Rupert, D. Sadler, J.M. Speirs, threatened or rare in many parts of T. Sprague, P. Taylor, R Tozer, its range. Nonetheless, the Ontario R Tymstra, R Weir, P.A. population is small, localized and WoodlifTe, A. Wormington and the peripheral to the main breeding Long Point Bird Observatory. We range, and the Prairie Warbler are grateful to the Ontario warrants designation as a 'rare' Breeding Bird Atlas and its species in Ontario (and Canada). coordinator, Mike Cadman, for Acknowledgements making available preliminary Atlas We would like to thank all those results from 1981-1984, while 115 people who responded to our Ross James provided access to questionnaire, since without their ONRS records and other data held help the Status Report could not at the Royal Ontario Museum. We have been written. In particular, thank Irene Bowman, Mike Don Sutherland and Don Fraser Cadman and Don Sutherland for provided a wealth of information. helpful comments on an earlier Others who contributed Canadian draft ofthis paper. The Status data were: K.F. Abraham, J.B. Report was prepared for the Armstrong, M. Bain, D. Barry, M. Nongame Program ofthe Wildlife Biro, C. Blomme, J. Bouvier, R Branch, Ontario Ministry of Bowles, D. Brewer, G. Carpentier, Natural Resources, and we thank W.E. Cattley, T. Cheskey, G.F. the O.M.N.R for permission to Clay, C. Cochrane, S. Connop, T. publish information contained in Crabe, D. Cuddy, H. Currie, R the Report. Curry, M.P. Davis, O.E. Devitt, B. DiLabio, P. Eagles, G. Literature Cited Fairfield, J.B. Falls, D. Ferguson, Ames, J.B. 1901. Nesting of D. Fidler, J. Francis, M. Gawn, Cory's Bittern (Ardetta neoxena) W.G. Girling, B. Gorman, M. and Other Notes. Auk 18: 106­ Gosselin, C.G. Harris, W.C. 107. Harris, B. Hartley, D.J. Hawke,' Bell, G.P. 1977. A Comparative J.M. Immerseel, W.R Jarmain, Biology of Three Provincial J.W. Johnson, A.J. Kelley, D. Parks in Southeastern Ontario. Kerr, R Knapton, S. Kozak, H. Environmental Planning Series, Krug, R Lawrence, J.B. Leather, Ontario Ministry of Natural H. Lumsden, J.D. McCauley, J. Resources, Parks Division, McCormick, T. McDonald, W.D. Eastern Region. McIlveen, S. McKinley, I. McLaren, K. McLaughlin, RD. Brewer, D. 1972. Prairie Warbler McRae, A.G. McVicar, J. Miles, (Ontario, Gibson River).

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Birdfinding Insert. Birding Harrington, P. 1922. Prairie 4:285. Warbler, Dendroica discolor. Brunton, D.F. 1979. Life Science Can. Field-Nat. 36:176. and Interpretive Potential of the Klugh, A.B. 1909. Notes on Some French River Study Area: A Birds ofBruce Co., Ontario. Pilot Study for the Proposed Ont. Nat. Sci. Bull. 5:25-26. Canadian Heritage Waterways Klugh, A.B. 1910. Present System. Ontario Ministry of Status of the Prairie Warbler in Natural Resources, North­ Canada. Ont. Nat. Sci. Bull. eastern Region, Sudbury, 6:34- 35. Ontario. 149 pp. Lambert, A.B. and R.B.H. Smith. Devitt, O.E. 1967. The Birds of 1984. The Status ofthe Prairie Simcoe County, Ontario. 2nd Warbler (Dendroica discolor) in revised ed. Brereton Field Canada. Report prepared for the Naturalists' Club. , Nongame Program, Wildlife Ontario. Branch, Ontario Ministry of Dingman, R.G. 1929. Letter to Natural Resources. 318 pp. J.L. Baillie, 2 December 1929. Lord, D. 1955. Occurrence of the Goodwin, CE. 1964. Worth Prairie Warbler at Georgian Noting. Ontario Naturalist 2:27­ Bay, Ontario. Ontario Field 30. Biologist 9:23-24. Goodwin, CE. 1982. A Bird­ Mills, A. 1981. A Cottager's Finding Guide to Ontario. Guide to the Birds ofMuskoka University ofToronto Press, and Parry Sound. , Toronto. 248 pp. Ontario. 209 pp. Goodwin, CB. and R.C Rosche. Nicholson J. 1981. The Birds of 1971. The Nesting Season, June . Sudbury, 1 - August 15, 1971: Ontario­ Ontario. 204 pp. Western New York Region. American Birds 25:851-856. Nolan, v., Jr. 1978. The Ecology and Behavior of the Prairie Goodwin, CE. and R C Rosche. Warbler Dendroica discolor. 1974. The Spring Migration, American Ornithologists' Union April 1 - May 31, 1974: Monograph No. 26. Allen Ontario-Western New York ~ Press, Lawrence, Kansas. 595 gion. American Birds 28:794-800. pp. Hanna, R. 1979. A Life Science North, F. 1943. Letter to J.L. Inventory and Evaluation of Baillie, 13 October 1943. McDonald Bay Park Reserve­ McCrae Lake Wilderness Area. Payne, R.B. 1983. A Dis- Ontario Ministry ofNatural ,tributional Checklist ofthe Birds Resources, Parks and Recrea­ ofMichigan. Misc. Publication tional Areas Branch, Central No. 164, Mus. of Zoology, Region. 61 pp. Univ. of Michigan. 71 pp.

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Quilliam, H. 1973. History ofthe J.L. Baillie, 27 November 1934. Birds of Kingston, Ontario. Saunders, WE. and E.MS. Kingston Field Naturalists, Dale. 1933. History and list of Kingston, Ontario. 209 pp. birds of Middlesex County. Ricker, WE. and CH.D. Clarke. Trans. Royal Can. Inst. 19: 161­ 1939. The Birds of the Vicinity 248. of Lake Nipissing, Ontario. Simpson, R. and H. Simpson. Contributions of the Royal 1973. The Biology ofBlack­ Ontario Museum of Zoology stone Harbour-Moon Island 16:1-15. Provincial Park Reserve, Parry SamuelL [sic] H. 1900. List of Sound District, Ontario. Ontario the rarer birds met with during Ministry of Natural Resources, the spring of 1900 in the Division ofParks, Parks immediate vicinity of Toronto. Planning Branch, Environmental Auk 17:391-392. Planning Section. 156 pp. Saniford, P. 1933. Letter to J.L. Sparling, J. H. 1965. The Sand Baillie, 30 April 1933. Dunes of the Grand Bend Saunders, WE. 1906. Birds New Region of Lake Huron. Ontario to Ontario. Naturalist Naturalist 3:16-23. 14: 205-207. Walkinshaw, L.H. 1959. The Saunders, WE. 1934. Letter to Prairie Warbler in Michigan. Jack-Pine Warbler 37:54-63.

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