TN10070 SOUTHERN BOG LEMMING SYNAPTOMYS COOPERI
PHYSICAL DESCRIPTION: IT IS A SMALL, ROBUST, MICROTINE RODENT WHICH WEIGHS 24-40 G (MN 7.4-27.5). IT IS MEDIUM SIZE (126 MM) WITH A TOTAL LENGTH OF 129 MM. THE TAIL IS 21 MM, THE HINDFOOT IS 20 MM, THE EAR NOTCH IS 9.5-12.5 MM (MN 8-14), AND THE TAIL IS SHORT, LESS THAN 25 MM. THE UPPER INCISORS ARE LONGITUDINALLY GROOVED *134,47,152*. THE UPPER PARTS ARE MIXED WITH BLACK, GRAY, AND YELLOWISH BROWN, GIVING A GRIZZLED CINNAMON BROWN APPEARANCE. THE UNDERSIDE IS GRAYISH WHITE OR GRAYISH CREAM. THERE IS NO SHARP LINE OF DEMARCATION ON THE SIDES. THE TAIL IS GRAYISH BLACK, BUT NOT SHARPLY BICOLORED, THE FEET ARE BROWNISH BLACK, AND THE EARS ARE NEARLY CONCEALED. IT IS DULLER IN COLORATION AND SMALLER THAN SYNAPTOMYS COOPERI HELALETES *152,134*. IT IS BRIGHTER THAN SYNAPTOMYS COOPERI STONEI *134*. REPRODUCTION: IN SOME LOCALITIES IT BREEDS THROUGHOUT THE YEAR, BUT PEAKS ARE IN THE SPRING AND FALL *6037,5407,141*. IN THE NORTHERN PORTION OF ITS RANGE, IT BREEDS FROM MARCH TO LATE FALL *PA5231*. THE NEST ARE USUALLY UNDERGROUND, BUT IT MAY BE ABOVE GROUND IN WARM WEATHER *6037,5407,47,252*. THE NEST RANGES FROM 6-8 IN. DIAMETER *6037* TO 10-20 CM DIAMETER *5407*. THE NESTS MATERIALS ARE GRASSES, LEAVES, HAIR, OR FEATHERS. THE GESTATION PERIOD IS 21-23 DAYS *47,252,6037,5407*. LITTER SIZE IS 1-7, USUALLY 2-5 *6037,5407,141*. UPON BIRTH THE YOUNG ARE ATRICIAL. THE YOUNG ARE WEANED AT 3 WEEKS *5407*. THE FEMALE CARES FOR THE YOUNG. IN THE WILD IT IS ESTIMATED TO HAVE ONE LITTER EVERY 67 DAYS, OR 3-4 LITTERS PER YEAR *6037*. THE MALES ARE SEXUALLY MATURE AT APPROXIMATELY 5 WEEKS. THE FEMALES ARE SEASONALLY POLYESTROUS IN MN, WITH POST-PARTUM ESTRUS WITHIN 12 HRS FOLLOWING PARTURITION. THE MALES ARE REPRODUCTIVELY ACTIVE FROM APRIL TO MID-NOVEMBER. THE MININUM AND MAXIMUM BREEDING AGES ARE UNCERTAIN, PROBABLY 5 WEEKS TO 1 YEAR IN THE WILD. |BEHAVIOR: THEY ARE ACTIVE ALL YEAR AND AT ALL TIMES OF THE DAY *4920,PA4764, 4833,PA4750,47,252* THOUGH IT IS LESS ACTIVE WHEN THE TEMPERATURE IS LESS THAN 20 F. *6037*. THEY ARE GREGARIOUS AND LIVE IN GROUPS IN A HOME RANGE WHICH IS NORMALLY LESS THAN 1/2 ACRE RANGING 0.1 ACRE TO AREA 100 FT. DIAMETER *6037*. THE HOME RANGE OF THE MALE IS 0.11 ACRE, WHILE THAT OF THE FEMALE IS 0.14 ACRE *PA8489*. HOME RANGE SIZE IN MN IS 1.19 ACRES *PA4739*. IT UTILIZES SURFACE AND SUBSURFACE TUNNELS. IT DEFENDS THE FEEDING, THE BREEDING, AND THE NESTING AREA DURING PERIODS OF FLOODING IN ITS PREFERRED HABITAT, THERE ARE SEASONAL SHIFTS OF THE HOME RANGE OR EXPANSION TO ADJACENT LANDS DUE TO HIGH POPULATIONS. TERRITORIALITY APPEARS REDUCED TO ABSENT *PA4764,PA4750*. IT FORAGES BY GLEANING AND GRAZING ON THE GROUND. TO FORAGE IT FORMS RECESSED RUNWAYS (OR UTILIZES THOSE MADE BY OTHER MICROTINES) THROUGH VEGETATION. THE RUNWAYS HAVE SIDE CHAMBERS WHICH ARE USED TO REACH NEW FOOD, TO FEED, TO REST, AND TO STORE FOOD. IT MAY FEED AT THE AREAS OF THE FOOD SOURCE OR CARRY FOOD TO A BURROW OR SIDE CHAMBER TO EAT OR CACHE. IT GETS FOOD DURING THE NIGHT AND THE DAY. WHOLE COMMUNITIES USE THE RUNWAYS. THEY ARE COLONIAL AND LIVE IN GROUPS OF A FEW TO SEVERAL LEMMINGS *6037,5407*. |ORIGIN: NATIVE *134,249,152*. |LIMITING FACTORS: THE LIMITING FACTORS ARE THE ABUNDANT FOOD SOURCE OF GREEN GRASSES AND SEDGES. IT NEEDS THE PRESENCE OF MOSS AND ERICACEOUS SHRUBS FOR COVER AND BURROWING. |POPULATION PARAMETERS: FEW INDIVIDUALS SURVIVE TO 1 YEAR. SURVIVAL RATE IS APPROXIMATELY 0.82 MOS. THE MALES OUTNUMBER THE FEMALES ( 3.66:1, 6.40:1, 1.83:1. THE RATIO MAY REFLECT DIFFERENTIAL TRAPABILITY AMONG THE SEXES. POPULATIONS MAY FLUCTUATE WIDELY, UP TO 35 PER ACRE *47*. |AQUATIC/TERRESTIAL ASSOCIATIONS: PREDATORS INCLUDE WEASELS, FOXES, COYOTE, HAWKS, OWLS, BOBCAT, DOMESTIC CATS, AND SNAKES *6037,PA5231, 141*. Synaptomys coperi is Pennsylvania's only short-tailed vole with grooved upper incisors *PA10176:1, PA11380:165*. The head appears proportionally larger than the body. A facial disk is produced upon erection of facial hair. Color of the dorsum ranges from bright chestnut to dark grizzled brown, the venter is silver to light gray. Juveniles are dark gray-brown, while sub-adult pelage resembles adults. The winter coat is longer and denser *PA10176:1*. Ranges of measurements (in mm.) are: total length (94-154); tail (13-24). hind foot (16-240; ear notch (8-14). Weights range from 21.49 to 50g. there is no signifient sexual demorphison *PA10176:1*. |ORIGIN WITHIN PENNSYLVANIA| Synaptomys cooperi is a native of Pennsylvania its range falling well within the overall geographical range of the species *PA10176:2, PA11787:832*. |BEHAVIOR| Only three records of home range studies are reported. One, done on a single individal in sphagnum moss habitat in Mantoba showed as area of 0.32 ha, another in a sphagnom bog n 9 individuals showed a range of 0.04 to 0.02 ha, with males ranging slightly more widely; another involving 7 individuals from a grass-dedge marsh showed an average of 0.00 ha for females, and 0.04 ha for males *PA10176:3*. There is no evidence for territorialism in Synaptomys, in fact some feel that the species is colonial,although probably not in a social context; they merely seem to cluster in disjunct populations *PA10176:48. |REPRODUCTIVE CHARCTERISTICS and REQUIREMENTS| Synaptomys builds a nest by enlarging its burrow in sphagnum or grass to about 6 or 8 inches n diameter, then lines it with grass and weed stems, and then finer grasses, and possibly fur and feathers. The nest is of fairly loose consturction and generally constructed 4-6 inches below the surface of the grund *5265:223*. Breeding occurs in all seasons of the year but in the eastern U.S. the frequency between November and February is vary low. One specimen is captivity produced 6 litter, the most common number of offspring being 3. Conception may occur during post-partum estrous, and gestatin taker 23-26 days *PA10176:2-3*a. The young are born pink and helpless with hair on the head and dorsum , as well as vibrissae. Eyes are closed, but claws are present. The young grow very rapidily for 3 wks then virtually stop. In 7 days the mammals are well furred, by 2 weeks their juvenal pelage appears and this begins the be replaced about 4 weeks, with adult pelage being achieved in 10 days. the female nurses the young for 16 days then they are weaned by the end of the third week. Eyes open in 10 days, ear pinnae unfold by the second day, and the incisors erupt in 6-8 days *PA10176:3*. It is unknown at what age the voles reach sexual maturity *84:106*. |POPULATION BIOLOGY| Population density estimates in forested areas are probably unreliable because of the difficulty of locating runways for trap placement. In areas with heavy ground cover where runways and other sign could be observed, densities have been found of 24, 34, 51 per ha. These owever, are thought to be local, temporary concentrations, and a more likely estimate for permanent residents is 4 to 12 per ha. In studies in Kansas some populations showed annual cycles of abundance while two other populatin demonstrated multiannual cycles *PA10176:38. Baker (1983) also comments onthe drastic fluctuations in Synaptomys population in Michigan *3854:339*. |LIMITING FACTORS| The major known limiting factor the presence of other voles of the genus Microtus which displaces Synaptonys from optimum to marginal habitat *PA10176:3-4, PA11380:165*. Synaptomys is almost completely nocturnal 86% of the field captures recorded occurred between sunset and sunrise *PA10176:4*, (1973) report that one can sometimes see circulr patches of grass, yellowed and dry where bog lemmings have nibbled at the stems from beneath the ground *PA11380:164*. During interspecific encounters with Microtus sp. synaptomys is usually submissive and disperses at a greater rate during populatio increases of Microfus. Synaptonys is thus confined to marginal habitat wher the two species are sympatric *PA10176:4, PA11380:165*. Physical description: The size of this species is medium with a total length from 119-135 mm. The tail length is from 17-25 mm and the hindfoot is from 18-20 mm. The upper incisors are longitudinally grooved *152*. The upper parts are brownish gray, the belly grayish, and the tail grayish black. They are not sharply bicolored. The feet are brownish black and the ears are nearly concealed. It has duller coloration and is smaller than Synaptomys cooperi helaletes *152,134*. Reproduction: This species breeds throughout the year, but there are peaks in the spring and fall. There are usually 3-4 litters per year. The gestation period is 21-23 days *47*. Origin: This species is native *152,134*. Behavior: This species is active all year and at all times of the day. They are gregarious and the home range is normally less than 1/2 acre. Populations may fluctuate widely and range up to 35 per acre. They utilize surface and subsurface tunnels. The nest is above and below the ground *47*. Physical description: The size of this species is medium with a total length from 119-135 mm. The tail length is from 17-25 mm and the hindfoot is from 18-20 mm. The upper incisors are longitudinally grooved *152*. The upper parts are brownish gray, the belly grayish, and the tail grayish black. They are not sharply bicolored. The feet are brownish black and the ears are nearly concealed. It has duller coloration and is smaller than Synaptomys cooperi helaletes *152,134*. Reproduction: This species breeds throughout the year, but there are peaks in the spring and fall. There are usually 3-4 litters per year. The gestation period is 21-23 days *47*. Origin: This species is native *152,134*. Behavior: This species is active all year and at all times of the day. They are gregarious and the home range is normally less than 1/2 acre. Populations may fluctuate widely and range up to 35 per acre. They utilize surface and subsurface tunnels. The nest is above and below the ground *47*.
References for Life History Codes
131, 47, 134, 152, 249, 252, 5881, PA4733, PA4764, 5265, PA4961, PA5231, 6037, PA7639, PA8094, PA8193, PA4764, PA8442, PA8489, PA8813, PA10176, PA4956, PA4950, PA7224, PA11380, PA11787, 3854, 84, 8905
Comments on Life History Codes