SUNY ESF
Moose

(Alces alces Gray)

From: Saunders, D. A. 1988. Adirondack Mammals. State University of New York, College of Environmental Science and Forestry. 216pp.

Order: Artiodactyla
Family: Cervidae

Range and Habitat

The range is the boreal forests of the northern hemisphere and, in Northern America, includes Alaska, Canada south to the tree line, and some northern and northeastern states.

The moose was once an integral part of the Adirondack fauna. No one can confidently attest to the species' demise, but Merriam's record of a 364 kg (800 lb) cow shot near Raquette Lake in 1861 is often cited as the last of the Adirondack's moose. Several unsuccessful, crude restoration attempts occurred around 1900, which would explain, for example, the young bull shot near Newcomb, Tahawus Upper Works, during the period 1907-1909. Occasional moose began to wander into the Adirondacks, from Canada and New England between 1935 and 1980, and have been permanent residence since at least 1980. In 1987, a small population of approximately 15-20 moose, including about 5 females, was known to be present in Adirondack Park. The preponderance of males results from the greater tendency for a male to disperse from the natal area, or be driven from it by resident, dominant bulls. Young males are most likely to wander hundreds of kilometers searching for mates and suitable range.

Intolerance to prolonged temperature above 24 ^oC (75 ^oF), and proximity to wetlands and early stages of successional vegetation are important determinants of moose distribution. The density of white-tailed deer may be an additional factor limiting distribution because of brainworm (Parelaphostrongylus tenuis), which is a parasitic roundworm that causes no serious effects in its primary host, the white-tailed deer, but may be fatal to moose. Moose and deer acquire this parasite during normal browsing when they accidentally ingest snails and slugs, which are the secondary hosts of the parasites. The influence of brainworm on the survival of Adirondack moose is not well known.

Food and Feeding Behavior

The moose is a herbivore, consuming 16-27 kg (35-60 lb) of plant materials daily. A moose uses its flexible upper lip and tongue to browse the nitrogen rich tips, twigs, stems, branches, and foliage of woody vegetation, and to graze herbaceous and aquatic plants.

A preference for aquatic plants during the summer probably relates to their higher sodium content. Moose graze by kneeling or by spreading or bending their front legs, and in this manner overcome the disadvantage of a short neck. Another feeding strategy entails walking over saplings to "ride down" the palatable terminal branches. Moose occasionally strip bark from trees. Willows, aspens, birches, alder, maples, dogwoods, cherries, American yew, balsam fir, white cedar, and easter hemlock are preferred food plants. (The larger size of the rumen and slower rate of passage of food through the four part stomach adapt the moose, unlike the white-tailed deer, to the use of balsam fir).

Activity and Movement

 In spite of the immense size, a moose can gallop for short distances at speeds of up to 56.4 km/h (35 mph). Wildlife photographers and nature observers should keep this in mind when approaching a bull during the rutting season or a cow with a calf. Under both circumstances, moose tend to be unpredictable and aggressive. The large hooves and strong slender legs permit travel through wetlands, and serve as paddles for swimming distances as great as 19.3 km (12 mi). These adaptations and a general diet explain the survival of moose in winter conditions that are intolerable to white-tailed deer. Snow must reach 102 cm (40 in) in depth before it hinders moose, and they may bend their forelegs under them, much like snowshoes, to move forward in deeper snow.

Reproduction

The breeding season or "rut" of the moose begins in early September, when the velvet of the antlers is shed (actually rubbed off against shrubs and saplings), and continues into November, after which the antlers are dropped. The rash of moose sightings in the Adirondack Park in September-November reflect the onset of the rut and the typical searching pattern of adults seeking mates. Bulls locate cows by scent, sound and sight, consorting a week or more with each one before finding another. To some extent, cows may also wander at this time. Following an exchange of postural, tactile and chemical signals, the bull copulates with a cow. Estrus lasts only 24 hours and recurs every 20-22 days until the cow is bred. Some bulls unable to locate cow moose may court domestic livestock, e.g., dairy cows, which to these bulls resemble a cow moose. However, the two species are not capable of mating successfully. Cows give birth to a single calf, occasionally twins, and rarely triplets in May or June after a gestation period of 240-246 days. The number of calves is a function of the cow's state of nutrition and age. At birth, the woolly, light brown, unspotted calf weighs 25-25 pounds, and moves about awkwardly on spindly legs. Growth is rapid, and by the second month, a calf gains 0.9-2.3 kg (2-5 lb) daily. Calves begin to browse at 3 weeks of age, and are weaned at 5 months. Cow moose defend their young rigorously against predators, lashing out with powerful, well aimed hooves.

Knowledge about sexual maturation is sketchy, by possible both sexes are capable, though unlikely to breed at 16 months of age. Prime reproductive age is from 6-10 years, but may extend much longer. Longevity is 18-23 years, although few individuals attain these ages.

Predators

The black bear is the only potential predator of moose calves in the Adirondacks.

Social Behavior

• Social System - Relatively asocial, moose may "yard" up in small groups of up to 12-15 in winter, drawn together by advantageous snow conditions and food. During spring and summer, small groups of bulls known as satellites may form. Again, during the rutting period, temporary associations of bulls occur with aggressive interactions producing hierarchies in which the top ranking bull gains access to cows. Cow-calf, and even cow-calf-yearling, are other social groups. The moose is polygynous, i.e., one male mating with several females, successively. Home ranges vary with many factors, but average 20.7-38.8 km² (8-15 sq mi). Cows with calves remain isolated from one another, and some may defend territories. Densities in habitat comparable to the Adirondacks are 1-2 moose per 256 ha (1 sq mi).
• Communication - Extensive, ritualized posturing occurs among moose, involving special gaits, especially among bulls in which the antlers serve as optical reinforcers, signals of size and motivation. Bulls engage in mock battles, pushing and shoving with their antlers, occasionally resulting in injury or death of one of the combatants when the encounter progresses to actual fighting. Bulls may also threaten by lowering their antlers and raising their manes while standing laterally to an intruder or opponent. Chemical signals play a major role in courtship. Metatarsal and interdigital glands are absent, but small tarsal and lacrimal glands are functional. Bulls during the rut use their hooves to flail out chunks of soil, and then stretch over the disturbed area to urinate on it, creating a wallow in which both sexes roll. Bulls and cows employ sounds to communicate. Bulls produce "roar-bellows", "croaks", and a "barking-like" sounds during agonistic and sexual encounters. Cows "moan", a directional "distance reducing" call that attracts bulls. Calves "moo-bawl." Of the various senses, hearing and smell are most acute with vision relatively poor.

Additional References

Franzmann, A. 1981. Alces alces. Mammalian Species, 154:1-7.

Garner, D.L. 1989. Ecology of the moose and the feasibility for translocation into the Greater Adirondack Ecosystem. M.S. Thesis, SUNY ESF,
Syracuse, 118 pp.

Garner, D.L. and W.F. Porter. 1991. Prevalence of Parelaphostrongylus tenuis in white-tailed deer in northern New York. Journal of Wildlife Diseases, 27(4):594-598.

Hicks, A. 1986. The history and current status of moose in New York. Alces, 22:245-52.