Life Histories of Subarctic Ants

Abstract

ABSTRACT. Ant species belonging to seven genera occur in habitats near the tree line in the Northern Hemisphere. An analysis of colony founding strategies suggests that in addition to physiological cold resistance, behavioral and sociometric adaptations might be important for survival and propagation of ants in subarctic biomes. Key words: polygyny, budding, ants, Formicidae, Leptothorax &SUMÉ. Des esphes de fourmis appartenant B sept genres vivent dans des habitats aux environs de la limite d'arbres. Une analyse des strat6gies de fondation des soci6t6s suggbre que, en plus d'une r6sistance physiologique au froid, des adaptations sociomktriques et comportementales pourraient être importantes pour la survie et la propagation dans les biomes subarctiques.

Cost to the cavity-nest ant Temnothorax crassispinus (Hymenoptera: Formicidae) of overwintering aboveground

“…Many species survive in places that protect them against extreme temperatures (e.g. under the soil surface) or have special adaptations that enable them to survive very low temperatures (Heinze, 1993;Leather et al, 1995). It is unknown whether the ant T. crassipinus has any physiological adaptations that enable it to withstand low temperatures.…”

The ant (Hymenoptera: Formicidae) communities of the central interior of British Columbia: Adaptations to a temperature-constrained environment.

“…The rare capture (twice in eighty samples in 8-10 yr post-harvest sites) of more than a dozen of L. muscorum workers, with a queen in some mini-Winkler litter extractions, does suggest that this small ant (body length <5 mm), with colonies consisting of a few dozen workers (Heinze 1993a), was possibly nesting in fine woody debris, litter, or soil. These cannot be confirmed as colonies, however, as queens were frequently captured (e.g., eight times in 80 samples in the 8-10 yr post-harvest sites) in the mini-Winkler litter extractions without workers.…”

“…Colonies are small, usually consisting of a few dozen workers (Heinze 1993a), although some nest populations can reach 100 or more . The boreal Leptothorax spp.…”

“…Variations in life-history strategies, such as an increasing frequency of dependent nest founding (Heinze 1993a;Seppa et al 1995) have been noted for boreal ants. This strategy, highly variable in its specific form, involves the establishment of new nests with a pre-existing supply of workers and is thought to be an adaptation to the high rate of mortality associated with independent nest founding by solitary queens (haplometrosis) .…”

“…Leptothorax muscorum (see Appendix III for more complete natural history) is a pioneer species in boreal forests (Punttila et al 1994), and is common in CWD (Higgins and Lindgren 2006). These small ants, with workers not exceeding 5.0 mm (typically 2.5-3.5 mm), form colonies consisting of a few dozen workers, often with multiple queens (Heinze 1993a). As Leptothorax spp.…”