87 Birds of Little Sachigo Lake and Thorne-Sachigo Rivers, Ontario by John M.e. Peterson Introduction that show on the best 1:250,000 A field party of the Ontario map available). Elevation is about Breeding Bird Atlas project 255 m. The stretch of the Thome­ composed of Theodore Mack, Sachigo Rivers explored is near Daniel Nickerson, Timothy Stiles 55°N latitude, between 90° and and the author spent 14-24 June 91°W longitude, and covers a 1985 at Little Sachigo Lake, distance of about 50 air km, with Kenora District and 25 June-4 elevations dropping from 160 m to July 1985 along the Thorne and 140 m. The area is 120-140 km Sachigo Rivers beginning at an NNW of Big Trout Lake, and unnamed lake ("Bald Eagle about 200 km south of Hudson Lake", see Figure 1). The purpose Bay. It is estimated that the party of the expedition was to gather canoed over 80 km at Little data from the two 100 x 100 km Sachigo and another 80 km or Atlas blocks (Blocks WL and XL) more along the two rivers and its in northern Ontario that had tributaries. received no previous coverage. Data were also obtained from a Relief third block (Block WK) at Little This is a generally flat land of Sachigo Lake. winding rivers, irregular lakes, and muskeg. An area shown on the Location topographical maps, and hence­ Little Sachigo Lake is located near forth referred to as Prominent 54°20'N latitude and 92°10'W Ridge, west of Little Sachigo Lake, longitude within 40 km of the hardly rises more than 30 m above Manitoba border, about 320 km the lake, and is forested with a from Hudson Bay, and 150 km mixture of balsam poplar (Populus west of Big Trout Lake (Figure 1). balsamifera), white birch (Betula The lake is about 12 km wide, papyrifera), and jack pine (Pinus eight kIn across, and is dotted with banksiana). islands (many more than the 18 John M.e. Peterson, Discovery Farm, RD 1, Elizabethtown, NY 12932 U.S.A. VOLUME 3 NUMBER 3 88 / / .. / j' / 55' / BALD EAGLE L, " / / / THORNE R, ~ / / '" 'J1' 2QKM / / / ~ LITTLE SACHIGO L. ••' 7 Figure 1. Map showing the two study areas: Little Sachigo Lake and Thorne-Sachigo Rivers. Drainage Of the 21 days spent in the field, it Little Sachigo Lake receives water rained on at least six. Rain began from Sachigo Lake to the south via the night of 20 June and continued the Sachigo River, and from without stop until 23 June. The smaller tributaries. Both the storm accompanied by high winds Thome and Sachigo Rivers join from the northwest blew down the Severn River flowing into trees around Little Sachigo Lake. Hudson Bay. The rivers trend On several other days strong winds southwest-northeast, flowing down and rains struck with little off the Shield to the Bay. Little warning. The weather station at Sachigo Lake is fairly silty due to Big Trout Lake reported that clay runoff entering the lake, during the first week of June there although the south-flowing streams was snowfall equivalent to 5 cm of on the north shore are clear. The rain. The 20-23 June storm Thome River is clear, but the produced an additional 8 cm of Sachigo is silty, in spite of rainfall, bringing the level of Big contributions from the Thome and Trout Lake up another 30 cm. By other clear side tributaries. 24 June, the beach at Camp 1 was mostly gone, and tents were moved Climate into the spruce forest above the The early summer of 1985 was clay bank. On 27 June the Thome unusually wet, with a profound was still in high flood stage, the adverse impact upon nesting birds. current flowing back into the ONTARIO BIRDS DECEMBER 1985 89 spruce forest on both sides, no Lake") south of South Wanita­ banks visible. Even by 4 July, wagao Creek. From the canoes when the mud residue on trees and and Camps 6-11, the Thorne and shrubs showed that the Sachigo Sachigo Rivers received thorough had dropped 1.25 m since the last coverage. For most of the river trip rain a week previously, the river bankside vegetation was under the was still flowing over the tops of floodwaters and the banks were bankside willows and bushes. The lined with flooded tall white spruce personnel at the weather station (Picea glauca). Near the river felt that this should be the wettest were forests of black spruce (Picea June on record for northern mariana), jack pine, and some Ontario and western Manitoba. white birch-balsam poplar, with The effect upon nesting birds, in fairly dense muskeg beyond. A the opinion of all four experienced large area of old burn lay behind observers, was devastating. Of 87 Camp 9 at the Thorne-Sachigo species recorded in Atlas Block confluence, where Common XL at Little Sachigo Lake over Nighthawks were particularly 137 hours between 14-25 June, 27 conspicuous. About a dozen side (31 %) were Confirmed. This low streams were also explored, some percentage actually dropped in for several miles upstream by Block XL along the Thorne­ canoe and on foot. Sachigo Rivers. Of the 80 species recorded over a period of 130 Habitats hours between 25 June and 4 July, There was a rich variety of only 13 (16%) were Confirmed. habitats, and successional types within; the conifer and broad­ Areas Investigated leaved forests, open habitats, and From Camps 1-4, the shoreline of wetlands. Except for the ruins of a Little Sachigo Lake from the trapper's cabin at Little Sachigo southeast outlet around the north Lake, a trapper's tepee at shore to Prominent Ridge in the Warnock Lake, and a new cabin west was investigated. Also along the Sachigo River, there was explored were an unnamed lake to little artificial disturbance by man. the south in Atlas square Black spruce is dominant around 15WK59, Warnock Lake to the Little Sachigo Lake, with some north, an unnamed lake west of mixture of white birch and balsam Warnock in 15WL50, and streams poplar on higher ground, especially leading to these lakes. The around the small lake to the south surrounding forests, muskegs, of the outlet where Least bogs, and side channels were Flycatcher and Ovenbird were intensively investigated, as were Confirmed, along Prominent Ridge all islands on the north (Block on the west shore, and several WL) side of the lake. ridges on the north side. Spruce Camp 5 provided a base for generally grades off into tamarack exploring the entirety of the (Larix laricina) in lower, wetter unnamed lake ("Bald Eagle areas, the latter species being VOLUME 3 NUMBER 3 90 dominant in several bog and of the edge habitat was under the wetland locations. The lake high floodwaters that sometimes provides open water, with islands intruded back into the spruce ranging from piles of bare forest. Ground cover was boulders, to brush vegetation, as sphagnum of various species well as those forested with conifers throughout the study areas, often or mixed woods. The shoreline of flooded to a depth of a 0.3 m or Little Sachigo is mostly lined with more. Patches of lichens were forests, although there are edges of generally found on drier ground willows (Salix sp.) or marsh in with well-drained sandy soil. No places, and at the east end there is ferns were observed. Many a narrow strip of sandy beach. familiar plants were found to be Shallow marshes are found near much smaller than their counter- . the outlet and up several streams, parts to the south. with cover varying from dense woody shrubs and cattails to The Bird Fauna flooded sedge meadows and Avian records were obtained from emergent buckbeans. Fens and a total of fifteen 10 km squares: bogs tend to blend into black two in block WK, three in block spruce forest. Interestingly, WL, and ten in block XL. The dandelions were noted at several variety of breeding birds in this grassy streamside embankments study area was extremely rich, used as campsites by our party, with 105 species found (and showing signs of previous use by several others undoubtedly Indians. present) around Little Sachigo White spruce borders much of Lake and along the Thorne­ the Thorne River, except where Sachigo Rivers. Variety was jack pine takes up higher ground generally better near the lake (93 along the banks. Mixed with and species) than on the rivers (80 dominant behind this curtain is species), although the later yielded black spruce. Black spruce also a dozen new species for the trip. A borders the lake where we landed highlight was the discovery of in square 15XL28 ("Bald Eagle Double-crested Cormorants nesting Lake"). Some mixed or pure on Little Sachigo Lake. Large stands of birch-poplar are found numbers of waterfowl took along the Thorne, becoming more advantage of the expanses of open frequent at lower elevations along water at Little Sachigo, including the wider Sachigo River. The all-male flocks of scaups, Common Sachigo is also bordered by a Goldeneyes, and Buffieheads. wider band of willow along its Common Loon, Green-winged banks. Much of the muskeg behind Teal, Mallard, Blue-winged Teal, the riverbanks was found to be Ring-necked Duck, and Lesser fairly dense, only rarely opening Scaup were Confirmed as breeding up, most notably around the old species at Little Sachigo, and burn near the confluence of the another seven waterfowl species two rivers. During our visit much noted there. Canada Geese were ONTARIO BIRDS DECEMBER 1985 91 Confirmed several times at the by the support and advice of a Thorne, Green-winged Teal number of farflung and helpful Confirmed on a beaver pond individuals and institutions.