102 Favourable Lake and Attawapiskat lakes where everyone took their Lake. Dr. Prince indicated that at chances, including the nonswimmer Favourable Lake they had a canoe Hope. Dr. Prince also indicated that and did portage it through the bush the raft used on Rathouse Bay was for many kilometres in order to the property of the local people who access remote lakes. When setting were very helpful at all times. and hauling nets in lakes near the The librarians at the ROM mine they tied two oil drums under a provided access to Hope's journals, couple of poles strapped across the and Charlotte Goodwin made copies struts of the canoe. These for me. The figure was prepared with "outriggers" prevented overturning. the assistance of Brian Boyle in the But they were hot portaged to other ROM Photography Department. Ross D. James, Department of Ornithology, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario M5S 2e6. Red Crossbills Feeding at Mineral Sources by Ron Tozer Introduction dog urine (Lawrence 1949); material The habit of various cardueline from cattle salt blocks (Marshall finches, including the Red Crossbill 1940); salt spilled around ice cream (Loxia curvirostra), to feed on sand freezers (Dawson et al. 1965); and and salt spread on road surfaces in "the material left in salt pork winter has been widely observeu and barrels" thrown outside lumber reported (e.g. Meade 1942; Lawrence camps (Bent 1968)! It has been 1949, 1982; Bent 1968; Terres 1982). suggested that finches may be Very small stones (in the IIsand" ) are attempting "to satisfy a requirement ingested as a source of grit required for some mineral that they do not for digesting vegetable material in the obtain in sufficient quantity in their gizzards of these granivorous birds food" (Dawson et al. 1965) when (Lawrence 1949, Ehrlich et al. 1988). they undertake such behaviour. However, the apparent attraction to Observations of various feeding salt is not as readily explained, even activities by Red Crossbills recorded though it has been known for a long in Algonquin Provincial Park time (e.g. Fisher 1888). Red Crossbills increased my interest in the subject, have been observed feeding at a wide and so I undertook a search of the variety of seemingly unusual mineral literature to learn more about it. This sources, including: coal ashes on article summarizes what I found, and which salt had been thrown, soapy documents some of the sightings from dishwater, and snow discoloured by the Park. ONTARIO BIRDS DECEMBER 1994 103 Sodium during the rest of the year (Fraser Sodium sources have been reported 1985). Many of these pools and as attractions for various birds, puddles II are recharged with brine at mammals, and even butterflies each rainfall and show little tendency (Fraser 1985, Otis 1994). The birds for Na (sodium) levels to decline may be attracted due to mineral during the summer" (Fraser 1985). dietary deficiencies, as previously Several finch species have been noted. However, while the results of recorded Ilpecking in areas of damp experiments on sodium chloride soil near the salty water" of these metabolism in captive Red Crossbills puddles (Fraser 1985). Pools of this did not "exclude this possibility", it type in Algonquin Park are heavily was concluded that "the ingestion of used by moose (Alces alces), salt beyond that present in the food is especially during spring and early unnecessary for maintenance of summer, and also attract Red sodium balance and apparent good Crossbills. For example, on 27 health by crossbills" even after they September 1994, I observed fifteen were fed a vegetable diet 'Irelatively individuals appearing to ingest mud high in potassium and low in sodium, at a heavily trampled Ilmoose for many months" (Dawson et al. puddle" along Highway 60 near 1965). While we may not fully Kearney Lake, Sproule Township. On understand why Red Crossbills are 11 November 1994, at another attracted to sodium sources, there are "moose puddle" beside the highway many examples of its occurrence. near Park (Long) Lake, Finlayson The most commonly observed Township, I counted about 40 Red situation which attracts Red Crossbills feeding on the mud. Crossbills, and other finches, to Sixteen individuals were tightly sodium involves birds on roads in clustered on a small stump (which winter. De-icing salt (sodium appeared to have been previously chloride), usually mixed with sand, is submerged in the muddy water), commonly spread on roads and can crawling over it and probing in its be available to finches in massive crevices like a group of miniature parrots! quantities. For example, Fraser (1985) estimated that sodiun1 chloride was Natural mineral springs ("licks") spread on the Trans-Canada Highway can contain "50-200 ppm Na plus near Wawa, Ontario at a Ilrate of high levels of some other minerals" 30-40 tonnes/km" each winter! Red (Fraser 1985). These licks may have Crossbills can be attracted to this "14 to 120 times more sodium" than road salt in large numbers; for other nearby non-lick areas (Fraser instance, I counted over 300 birds 1980), and were recorded as major along a 20 knl stretch of Highway 60 attractions for birds such as Purple between the West Gate and Found Finch (Carpodacus purpureus) and Lake in Algonquin Park on 28 Pine Siskin (Carduelis pinus) in a February 1985. Also, due to the study at Sibley (now Sleeping Giant) heavy winter application of sodium Provincial Park (Fraser 1985). Speirs chloride, roadside pools of stagnant (1985) reported Red Crossbills water can develop a sodium content "hopping about our feet at a salt lick of 100 to 600 parts per million (ppm) at Montreal Falls by Lake Superior VOLUME 12 NUMBER 3 104 one summer". (L. leucoptera) and small numbers of Aquatic plants growing in shallow Red Crossbills that were ingesting a lakes and ponds are another rich mixture of calcium chloride and sand source of sodium, having up to 500 spread on a road in New York state times more sodium than leaves of during March. In this case it was woody plants (Fraser et al. 1980). theorized that the attraction might Moose consume large quantities of have been the fine gravel, a craving aquatic plants during summer, for salt, and/or moisture gathered by apparently because of a "specific the calcium chloride. hunger for Na" (Fraser 1980). Ingestion of supplementary Actively growing aquatic plants are calciurn in the breeding season has not a food source for finches, but been documented for several bird these plants may become an species in northern areas (Ficken attraction after they die. Red 1989). For example, nestling Lapland Crossbills are frequently observed Longspurs (Calcarius lapponicus) in feeding on exposed areas of "mud" Alaska "ate bones and egg shell (consisting of rotting aquatic plants fragments" (Seastedt and MacLean and their roots) at lakes and ponds 1971). Females might be attracted to which attract moose in Algonquin sources of this mineral since Park (e.g. six birds feeding on "mud" "calcium needs for egg laying may be at Hobo Lake, Finlayson Township, particularly high" (Ficken 1989). on 29 July 1994, reported by Doug Nethersole-Thompson (1975) Tozer). I suspect these crossbills are observed female Scottish Crossbills attracted to the sodiurn released from (L. scotica) nibbling "a capercaillie's the rotting aquatic vegetation at these (Tetrao urogallus) skeleton" and sites. carrying "a mountain hare's bone to the top of a pine", when breeding Calcium during March, and concluded that Seeds of Scots Pine (Pinus sylvestris) "these birds evidently needed and Norway Spruce (Picea abies), calcium". Similarly, Baily (1953) which were eaten by crossbills in reported that Red Crossbills had Finland, consisted of about 95 per secured "scrapings from the bleached cent organic matter and 5 per cent bones of deer" during the breeding inorganic matter (Pulliainen 1972 J. cycle. Nearly 4 per cent of the latter was Wood ash is rich in calcium, and nitrogen, while potassium, its consumption has been reported for phosphorus, magnesium and calcium various birds, both during the were contained in the remaining 1 breeding period and at other seasons. per cent. Such findings may suggest a Species reported eating ash include: calcium (or other mineral) deficiency Red Crossbills (Bent 1968); Parrot in the diet of crossbills. A wide Crossbills (L. pytyopsittacus) and variety of crossbill feeding behaviours Common Redpolls (Carduelis flammea) have been reported which may be (Pulliainen et al. 1978 J; Boreal manifestations of a hypothetical need Chickadees (Parus hudsonicus) (Ficken for calcium. 1989); and even hummingbirds Meade (1942) reported large (Trochilidae) (des Lauriers 1994)! In numbers of White-winged Crossbills the case of Boreal Chickadees, it was ONTARIO BIRDS DECEMBER 1994 105 shown that the ash where the birds by Red Crossbills, but it may well repeatedly fed was much higher in occur. calcium (2580 ppm) than nearby ash Red Crossbills in Crater Lake (600 ppm) where they never fed, National Park, Oregon, were suggesting an ability to detect richer observed to feed on a powdery crust concentrations (Ficken 1989). There ("probably made up of calcium salts have been numerous observations of dissolved from the rock material") Red Crossbills eating wood ash at that formed on cliff faces of pumice campfire sites in Algonquin Park (e.g. (Aldrich 1939). The crossbills clung to three males and two females at the cliff faces, placed their heads Opalescent Lake, Stratton Township, sideways against the crust (which 9 September 1963, reported by Russ was loose and only one-sixteenth of Rutter). an inch thick), and licked it off with Parrot Crossbills in Finland were their tongues while holding their bills reported eating the outer layer of open widely (Aldrich 1939). This decaying old pine logs, in the walls of same manner of feeding has been buildings and lying on the ground.