Contents the ANTS of ISLE ROYALE, MICHIGAN
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AN ECOLOGICAL SURVEY OF ISLE ROYALE, ridges, running about on the surface and through the thin deposits of soil. The specimens of No. 73 were from the LAKE SUPERIOR rock pools on the shore just south of Tonkin Bay." This ant, like the preceding, extends its range into the PREPARED UNDER THE DIRECTION OF Northern and Eastern States, but it is by no means CHAS. C. ADAMS. common. It is abundant, however, at higher elevations A Report from the University of Michigan Museum, published (8000-9000 ft.) in the Rocky Mountains and at lower by the State Biological Survey, as a part of the Report of the elevations in Nova Scotia. Board of the Geological Survey for 1908. LANSING, MICHIGAN WYNKOOP HALLENBECK CRAWFORD CO., STATE PRINTERS Subfamily Dolochoderinae. 1909 3. Tapinoma sessile Say. Workers from a single colony: 132 (V, 2) C. C. Adams, "under Cladonia." This is the only Dolichoderine ant which ascends to high latitudes Contents and elevations. I have found it nesting under stones at 8. The Ants of Isle Royale, Michigan, by Dr. William altitudes of over 10,000 ft. near Cripple Creek, Morton Wheeler.. ............................................................. 1 Colorado., and it is common in the Canadian zone throughout the Rocky Mountains. In the Northeastern 9. The Cold Blooded Vertebrates of Isle Royale, by States it descends to sea-level. Dr. A. G. Ruthven. ........................................................... 3 10. Annotated List of the Birds of Isle Royale, by Subfamily Camponotinae. Max Minor Peet................................................................ 6 4. Lasius niger L. var. neoniger Emery. Workers from I. Introduction................................................................ 6 five colonies: 20 (I, 5) C. C. A., .and 75 (I, 1), 79 (I, 5), II. Classified List of Birds Observed in 1905................. 7 82 (I, 5), 83 (I, 5), H. A. G., "Abundant on the rock ridges 1. Summer Residents. ............................................7 and jack pine ridges (I, 2, 5). The nest is always 2. Migrants. .............................................................7 constructed beneath or at the side of a flat or angular 3. Winter Residents (migrants from the north)........7 stone, at a depth of one decimeter or more. A 4. Permanent Residents. ........................................7 complicated system of roomy galleries is excavated with III. Annotated List.......................................................... 7 passages 1.5-2.5 cm. high by 2-5 cm. broad. This ant 11. Notes on Isle Royale Mammals and their was seen to capture and kill a beetle. No. 75 H. A. G, is Ecological Relations, by Dr. Chas. C. Adams ............ 35 material from the rock pools." (Gleason). I. Introduction.............................................................. 35 There are in North America three distinct varieties of the II. Mammal Successions............................................. 36 circumboreal L. niger, viz., var. neoniger Emery, sitkäensis Pergande and americanus Emery. The first 1. Lake-Pond-Swamp Series ................................36 and second have the legs and antennae of the workers 2. The Land Series................................................36 and females covered with suberect hairs, and the hairs III. Faunal Affinities and Migrations. ........................... 37 on the body are also conspicuously abundant. L. 1. The Geographic Affinities of the Fauna ............37 neoniger is small and black, sitkäensis much larger and 2. Post-Glacial Origin of the Fauna.......................37 of a lighter brown or yellowish color. L. americanus is IV. Annotated List. ...................................................... 38 small, like neoniger, but brown and has few erect hairs on the body and none on the legs and scapes. It is closely related to the palearctic variety alienus Forster, THE ANTS OF ISLE ROYALE, and like this form inhabits warm and rather dry localities. MICHIGAN. It is the common form of niger throughout the Northern BY DR. WILLIAM MORTON WHEELER. States. L. sitkäensis occurs in Alaska, Nova Scotia, and Harvard University. in the damp alpine meadows of the Rocky Mountains at altitudes between 8000 and 9000 ft. L. neoniger occurs Subfamily Myrmicinae. in dryer situations at somewhat lower elevations and is occasionally found even near sea-level in isolated 1. Myrmica brevinodis Emery var. canadensis Wheeler. colonies in our northern woods. Varieties (hybrids?) Several workers from a single colony: 61 (I, 2) H. A. intermediate between neoniger and americanus also Gleason. "Found on the dry rock ridges under the mats occur in these same localities. of bearberry and also excavating nests in the crevices of 5. Formica sanguinea aserva Forel. Workers from two rocks to a depth of some 8 cm." This is the common colonies: 78 (I, 2), 72 (I, 2) H. A. G. "This is one of the variety of the subspecies brevinodis at higher elevations commonest species on the rock ridges, but constructs its in Canada and the Eastern States. nest either in or under decaying wood. On the ridge 2. Leptothorax acervorum canadensis Provancher. north of the light house, a nest (72) was made under a Workers from three colonies: 63 (I, 2), (I, 1), 77 (I, 2), H. rather small rotten stick, and the soil beneath was A, G. “Abundant in Cladonia clearings and on rock composed mainly of finely comminuted fragments of the Isle Royale, 1908 / Part 2 - Chapters 8-11 – Page 1 of 53 wood. The second colony (78) had constructed a nest in are present in the largest as well as in the smallest the interior of a large decaying log." (Gleason). This workers. Teeth of mandibles black. subspecies has been taken hitherto only at Toronto Described from numerous specimens taken from a (Forel), on the summit of Mt. Washington (Mrs. A. T. single colony: 115 (1, 6) H. A. G. A dozen workers Slosson), among the Litchfield Hills of Connecticut taken by myself on Pikes Peak, Colorado, near timber (Wheeler) and in Casco Bay, Maine (Wheeler). It is a line, at an altitude of 10,500 to 11,000 ft. differ from the decidedly boreal form, approaching the typical palearctic Isle Royale specimens only in having the frontal area sanguined in size and coloration. There were no slaves smooth and shining, in having the middle of the petiolar accompanying the specimens from Isle Royale, a fact border produced upward as a distinct, blunt point, and in which tends to confirm the conclusions of Forel and the less extensive infuscation of the bead, pro- and myself that this subspecies usually lives in pure colonies. mesonotum. These specimens may be regarded as 6. Formica adamsi sp. nov. Worker. Length 3.5-5 mm. representing a distinct variety, alpina var. nov. Both this Allied to F. rufa L. Head, including the mandibles, nearly and the typical adamsi may be distinguished from our as broad as long even in the smallest individuals, with other North American forms of the rufa group by their straight posterior border, rounded posterior corners, and small size, opaque surface and peculiar coloring and slightly but distinctly convex sides. Eyes large. pilosity. The following collector's note on the Isle Royale Mandibles 7-8 toothed. Clypeus prominently carinate, specimens adds some ethological characters which are with broadly rounded anterior border, not produced in not seen in the other small forms of the rufa group the middle. Palpi of moderate length. Antennae known to me: "The nests of this ant are one of the most slender, scapes nearly straight at the base, funicular conspicuous features of the drier tamarack swamps. joints all distinctly longer than broad, the basal They are rounded-conical in shape, 3-6 dcm. high or somewhat more slender and longer than the apical even larger and with a diameter at the base about joints. Pro- and mesonotum moderately rounded, equalling the height. They are composed within of convex, the latter eliptical and nearly twice as long as Sphagnum, but as would be expected with such broad, the former a little broader than long. Epinotum material, without any definite system of galleries. The with subequal base and declivity, the former slightly outer surface is thickly covered with leaves of convex, the latter flattened or slightly concave; the two Cassandra, probably to prevent loss of moisture by surfaces in profile passing into each other through a evaporation from, the interior. They are frequently rounded angle. Petiole more than half as broad as the placed near or under a bush of the Cassandra, but the epinotum, in profile with convex anterior and flattened same covering is used if no Cassandra is near." (H. A. posterior surface and sharp upper border; seen from Gleason). behind the border is rounded and but feebly or not at all 7. Formica rufa obscuriventris Mayr. Workers from six produced upward in the middle. Gaster and legs of the colonies: 46 (I, 1), 47 (I, 1), 63 (I, 2), 76 (I, 2), 114 (I, 6), usual shape. 14 (112) H. A. G. "This subspecies occurs on the rock Opaque throughout; only the mandibles, frontal area and beaches (I, 1, 46, 47) where it forages about on the sides of the clypeus faintly shining or glossy. Mandibles surface and in crevices but is more abundant on the jack finely and densely striated. Surface of body densely and pine ridges (I, 5, 63) and on the rock clearings (I, 2, 76)." indistinctly shagreened. I recently described this subspecies as F. dryas, but an Hairs and pubescens pale yellow; the latter covering the examination during the past summer of some of Mayr's whole body and appendages, not conspicuous except on types in Professor Forel’s collection, shows that in so the gaster, but even on this region not sufficiently dense doing I created a synonym. Mayr's original description to conceal the surface sculpture. Hairs short, sparse based on specimens from Connnecticut is entirely and obtuse, in several rows on the gastric segments; on inadequate, and the list of localities which he later cited the thorax confined to the upper portions of the pro- and for obscuriventris shows that he lumped together a mesonotum, on the head to the clypeus, front and number of different forms belonging to the rufa group.