Land Snails of Montana

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Whitney Tilt, Conservation Chatter, May 2017.

Geologic Fossil?

You’re walking through the forest in Montana and your eye catches a glimpse of something round and white. On closer inspection, it’s a shell, bleached chalky white with its former occupant long gone. Is this some remains of marine mollusks that dwelt here thousands of years ago or something more recent? 

You haven’t found a fossil; you’ve found the shell of one of the numerous species of terrestrial snails roaming Montana. Some of the common names of species you might find in our part of Montana gives you an idea of how varied they are: ambersnail, glossy pillar, mellow column, forest disc, and quick gloss. 

The live snails can be found under logs, leaf litter and duff. But keep your eyes out for the sun-bleached shells while you hike around Montana.

Forest Disc (Discus whitneyi)

Diagnostic Characteristics: A combination of shell shape (flattened heliciform or flattened conic), shell dimensions, number of whorls, shell color (olive-brown and chitinous), the presence of ribbing on the shell, lack of reflected lip, and absence of teeth in the aperture.  

Habitat: Forested areas, from mesic (Engelmann spruce, Douglas-fir, secondary canopy including alder, mountain maple, dogwood, willow) to relatively dry (ponderosa pine and Rocky Mountain juniper, but usually in moister sites, such as imbedded pockets of aspen). Found under woody debris and rocks, in downed rotten wood, leaf litter and duff.

Subalpine Mountainsnail (Oreohelix subrudis)

Diagnostic Characteristics: Medium to large size, calcareous whitish to gray (some may be brownish), moderately elevated spire (sometimes almost bee-hive shape), variable banding, relatively narrow umbilicus, absence of reflected lip, and surface sculpture help distinguish this from most other larger shells.

Habitat: relatively moist sites, along stream courses and near seeps or springs, sometimes in talus slopes. Live animals present mostly in leaf litter, and under downed wood, rocks, and in duff or soil accumulations under wood and rocks.

Sources & Resources:

Montana Field Guide. http://fieldguide.mt.gov/displayFamily.aspx?order=Stylommatophora

 Hendricks, P. 2012. A Guide to the Land Snails and Slugs of Montana. A report to the U.S. Forest Service - Region 1. Montana Natural Heritage Program, Helena, MT. vii + 187 pp. plus appendices. 

Grizzly Bears in the Greater Yellowstone Ecosystem

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Whitney Tilt, Conservation Chatterm June 23, 2017. Rangemap updated in 2023.

Gfrizzly bear in Yellowstone national park (jim peaco, public domain)

STATUS

The Grizzly Bear (Ursus arctos) once roamed much of western North America. Presently it is found in five distinct populations in the conterminous United States, including the Greater Yellowstone Ecosystem (GYE), see map. The species has been listed as threatened with extinction under the Endangered Species Act (ESA) since 1975. Since its listing, a great deal of effort has been made to conserve the species including removal of livestock, especially sheep, from the GYE recovery area; clean-up and lock-up of garbage and other bear attractants; and stronger education and law enforcement to prevent accidental shootings and poaching. While most would agree that substantial progress has been made, there is a great deal of disagreement surrounding the bear’s status and whether to delist the species in the GYE.

In 1993, a recovery plan was implemented with three specific goals that had to be met for six consecutive years. In 2003, those recovery goals were met and the U.S. Fish and Wildlife Service (FWS) proposed to delist the bear in 2005. The proposal was shelved after significant resistance from environmental interests, and the recovery plan was modified with updated population and mortality methodologies. The GYE population continued to meet recovery goals and was removed from the ESA in 2007. Lawsuits were immediately filed and in 2009 a federal district judge overturned the delisting and put the species back on the threatened list. The judge ruled that 1) the Conservation Strategy, under which the bear would be managed by state and federal agencies, was unenforceable; and (2) the FWS did not adequately consider the impacts of the potential loss of whitebark pine nuts, a grizzly bear food source.

Map courtesy of Interagency grizzly bear committee

Responding to the 2009 decision, an Appeals Court ruled in 2011 that the Conservation Strategy did, in fact, provide an adequate regulatory mechanism, but upheld the lower court’s ruling on whitebark pine and other foods.

In 2013, the Yellowstone Ecosystem Subcommittee, the Interagency Grizzly Bear Committee, and Interagency Grizzly Bear Study Team again recommended the species be removed from the threatened species list, specifically adding that alternative foods are available and the reduction of whitebark pine did not appear to have a significant impact on bears.

In March 2016, FWS again proposed to remove the species from the ESA, by reason of recovery. On June 22, 2017, the Department of the Interior announced that the Yellowstone population of the grizzly bear has recovered to the point where federal protections can be removed and overall management can be returned to the states and tribes.

DOI concludes the population has met and exceeded all criteria for delisting, including: 1) estimated population size, 2) distribution of females with cubs, and 3) mortality rates.

1.       Population Recovery target: ≥ 500 bears in the recovery area (criteria instituted in 2014): achieved in 2014 and 2015. In 2015, there were an estimated 717 grizzly bears in the GYE, an increase from 136 in 1975.

2.       Distribution Recovery target: Objective of 48 females producing cubs annually: achieved since 2006. Earlier target was female grizzlies with young occupying at least 16 of the 18 bear management units that comprise the Primary Conservation Area in the GYE. This goal has been met since 1998.

 3.       Mortality:

a) Estimated percent of total mortality of independent-aged females not to exceed 7.6% (lowered from 9% in 2012): achieved 2006-07, 2009-10, 2012-14.

 b) Estimated percent of total mortality of independent-aged males not to exceed 15%: achieved 2006-07, 2009, 2012-15.

 c) Estimated percent of mortality from human causes for dependent young not to exceed 7.6% (lowered from 9% in 2012): achieved 2006-15. Earlier standard was bear mortality must be limited to no more than 4 percent of the total population. This goal has been met since 1996 with the exception of one year.

  •  In 2015, there were 59 known and probable grizzly bear mortalities in the GYE: 34 attributed to human causes; 4 of undetermined cause; 2 were natural deaths; and 19 unknown.

While there are plenty of opinions on all sides, the primary concern by opponents to delisting is the fear that protection for the GYE grizzlies will disappear if they are taken off the ESA list. In fact, years of effort have gone into crafting a conservation package for Yellowstone’s grizzlies to ensure that the bears continue to thrive once taken of the list. Developed by federal and state natural resource management agencies, the Conservation Strategy provides an impressive set of protections including a six-million-acre core Primary Conservation Area, protections against excessive take, and extensive monitoring. A solid framework is in place to ensure that continued grizzly bear conservation will follow delisting. As the needs of Yellowstone grizzlies change or increase, so will the tools and protections needed to meet them.

Outside the courtroom and the court of public opinion, management of bears changes little whether it is listed under the ESA or not. Land agencies will continue to manage the bear and scientists will continue to monitor the long-term recovery goals, and members of the public will sit in judgement.

BEING SMART IN GRIZZLY COUNTRY

In 2015, a human-grizzly conflict inside Yellowstone National Park resulting in one dead human, the killing of the mother grizzly, and removal of two, now-orphaned cubs to a zoo. This event was tragic for humans and bears alike. Humans deaths from grizzly attack are rare, especially in light of the number of potential interactions of grizzlies and humans as they overlap in time and space. In Yellowstone National Park, the number of bear-inflicted human injuries has averaged less than one injury per one million park visits each decade from 1970 to 2014. From 1980 to 2014, 37 people were injured by grizzly bears in Yellowstone (an average of 1.1 injuries per year).

Grizzly bears can be dangerous.  Considering their size, strength, and potentially aggressive nature, it is remarkable that they don’t injure or kill people more often than they do. To be prepared one must take responsibility for their own safety in grizzly country.  The following advice is compiled from People and Carnivores:

  • The most important tool for staying safe is situational awareness -- "knowing what is going on around you." 

  • Pay attention to where you are – can you see very far?  Is there terrain or vegetation that could hide a bear from your view?  Many people have an unrealistic ‘search image’ -- they assume that grizzlies are huge, and therefore easy to see.

  • Be aware of wind direction. If the wind is in your face as you walk, that means your scent is being carried away from any bears that may be ahead of you. In our experience, grizzlies that can catch your scent will typically leave once they know what you are.

  • Stay alert for fresh bear sign as well. Tracks may not always be obvious – look also for scat, rub trees, or fresh digging (excavating roots, insects, or rodents).  Bears will often tear apart logs or flip rocks seeking food.·         One of the most dangerous situations to walk into is a grizzly that has claimed an animal carcass.  The bear’s inclination will be to defend this food source.  Look and listen for scavenger birds like ravens and magpies.   You may be able to smell a carcass from some distance if the wind is right.  If you do detect a carcass, take a wide detour around it, or turn around if there is no option to detour.

  • Bears tend to be most active at dusk and dawn, but that doesn’t mean you can’t encounter one in midday.  Bears often sleep during the day in thick timber.  Move carefully, and stop frequently to listen, when travelling through such places.

  • Have bear spray and know how to use it. Bear Pepper Spray is a highly effective, easily used deterrent against aggressive bears and other animals.  To use bear spray:

    • Remove safety clip

    • Aim slightly down and towards the approaching bear.  Adjust angle for wind direction.

    • Spray a brief shot when the bear is roughly 30 feet away.

    • Spray again if the bear continues to approach.

    • Once the animal has retreated or is busy cleaning itself, leave the area as quickly as possible, but do not run.  Alternately, go to an area of safety, such as a car.

    • REMEMBER: Bear pepper spray is only effective when used as an airborne deterrent sprayed as a cloud at an aggressive animal.  It should not be applied to people, tents, packs, other equipment or surrounding area as a repellent.

Many aggressive encounters with grizzlies happen very quickly.  Some are probably too instantaneous for a person to be able to react with either bear spray or a firearm.  To give yourself a margin of safety, carry your bear spray in a consistent and accessible place on your person (or on your saddle if you are horseback and prefer it not be on your person). Practice reaching for the spray until it becomes second nature to reach for it.

Courtesy of Center for Wildlife Information – Graphic Art Fund

GRIZZLY FACTOIDS

APPEARANCE. The grizzly bear’s color varies from blond to black, often with pale-tipped guard hairs (hence the name “Grizzly”). The coloration of black and grizzly bears is so variable that it is not a reliable means of distinguishing the two species (see comparison of grizzly and black bear below).

DIET. Bears are omnivores with a wide ranging and flexible diet, consuming different foods depending on location and season. Preferred foods include army cutworm moths, whitebark pine nuts, ungulates (elk, bison), and cutthroat trout. Bears in the GYE are known to consume at least 266 species of plant (67%), invertebrate (15%), mammal (11%), fish, and fungi. They will readily eat human food and garbage where they can get it. Their caloric requirements are: normal (May-Sept): 5,000-8,000 kcal/day; hyperphagia (a determined push for calories in advance of hibernation): 20,000 kcal/day; hibernation 4,000 kcal/day.

HIBERNATION. Grizzly bears hibernate in response to seasonal food shortages and cold weather. The location and nature of dens is variable, but typically dug in sandy soils, at base of large trees, on north-facing slopes (30-60 percent grade) at 6,500-10,000 feet elevation. In hibernation, body temperatures fall some 12 degrees F, slowing their metabolism by 50-60%. Bears sometimes awaken and leave their dens during the winter, but they generally do not eat, drink, defecate, or urinate during hibernation. They live off of a layer of fat built up prior to hibernation, and will lose some 15-30% of their body weight.

EMERGENCE. Bears emerge from their dens as temperatures warm and winter-killed ungulates and early spring vegetation become available. In the GYE, bears begin to emerge from their den in early February, and most bears have left their dens by early May. Males are likely to emerge before females.

REPRODUCTION. Female Grizzly bears (sows) rarely breed before age four, and the average age of first reproduction in GYE is 5.8 years. Once of reproductive age, females typically become pregnant once every three years. Implantation of a fertilized egg in the uterus is delayed so the embryo does not begin to develop until late November or December, about one month after the sow has denned. In late January or early February, the sow gives birth to 1-2 cubs, sometimes three, rarely four. At birth the cubs are hairless and blind, are about eight inches long, and weigh 8-12 ounces. The cubs do not hibernate but nurse and sleep next to the mother. At 10 weeks, the cubs weigh about 10–20 pounds. Male (boar) bears take no part in raising cubs, and may actually pose a threat to younger bears (see mortality). Grizzly bear cubs usually spend 2½, and sometimes 3½ years with their mother before she or a prospective suitor chases them away so that she can mate again. Females frequently establish their home range in the vicinity of their mother, but male cubs disperse farther.

GENUS/SPECIES: Ursus arctos is the North American Brown Bear, or Grizzly. Ursus (Latin for “bear”) and arctos (Greek for “bear”). There are several distinct subspecies including the Mainland Grizzly, U. arctos horribilis, found in the lower 48 states and the Kodiak bear, U. arctos middendorffi, on Kodiak Island, Alaska, the largest of the brown bear subspecies.

COMMON NAMES: grizzly bear, brown bear, silvertip.

LIFE SPAN: 20-30 years; oldest known in GYE 31 years.

SPEED: 35-40 mph.

CLAW LENGTH: average 1.8 inches (45 mm), longest 5.9 inches (150 mm); claw length and shape allow efficient digging of foods from the ground but are less efficient for tree climbing than black bear claws.

TREE CLIMBING ABILITY: cubs and younger, smaller bears are proficient tree climbers; however, adult male and female grizzly bears are also capable of climbing trees.

BODY TEMPERATURE: 98-101°F (36.5-38.5°C) during active season; 94-95°F (34.4-35°C) during hibernation.

RESPIRATION: 6-10 per minute; <1 per minute during hibernation.

HEART RATE: 40-50 beats per minute; 8-19 beats per minute during hibernation.

VISION: on par with human vision; exhibits color vision and excellent night vision.

AVERAGE WEIGHT: adult male = 413 lb. (187 kg); adult female = 269 lb. (122 kg).

AVERAGE HOME RANGE SIZE IN GYE: males = 337 square miles (874 km2); females = 109 square miles (281 km2).

GESTATION: 235 days (implantation of embryo delayed until late November/early December).

BIRTH PERIOD/LOCATION: late January/early February in winter den.

DEN ENTRY: pregnant females- 1st week November; other females- 2nd week November; males- 2nd week November.

AVERAGE DENNING DURATION: females with cubs- 171 days; other females- 151 days; males- 131 days.

DEN EMERGENCE: males- 4th week March; other females- 3rd week April; pregnant females- 4th week April.

TYPICAL DEN TYPES: excavated (i.e., dug) = 91%; natural cavity = 6%; snow = 3%.

PERIOD OF MATERNAL CARE: 18 to 42 months; average = 30 months.

SURVIVAL RATE: cubs = 55%; yearlings = 54%; subadults = 95%; adult females = 95%; adult males = 95%

CAUSES OF MORTALITY (GYE): Human-caused (including management actions, hunter-related, vehicle-strikes, etc.) = 85%; Natural causes (including male grizzly attacks, malnutrition) = 15%.

 Everyone likes to watch bears: bear watching enroute to the chapel in Grand Teton National Park, photo © P.Potter

Everyone likes to watch bears: bear watching enroute to the chapel in Grand Teton National Park, photo © P.Potter

SOURCES & RESOURCES

2016 Conservation Strategy for Grizzly Bear in the Greater Yellowstone Ecosystem. U.S. Fish and Wildlife Service. 128 pages.

Grizzly Bear Recovery in the Greater Yellowstone Ecosystem. Yellowstone Science 23(2): December 2015. 98 pages.

People and Carnivores. www.peopleandcarnivores.org

 

Yellowstone Elk: Conservation and Management

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Whitney Tilt, Conservation Chatter, September 2016

Bull elk with cows (photo courtesy of Gallatin Wildlife Association)

ELK in the Greater Yellowstone

The Greater Yellowstone Ecosystem (GYE) is home to approximately 30,000–40,000 elk. Nine discrete herds, totaling 10,000-20,000 animals compose the Greater Yellowstone “superherd” whose summer range is in the core protected area of the GYE. Come winter, the majority of these animals will migrate to lower elevations, outside the park, while some will remain in the same area year-round. The timing and routes of elk migration closely follow the areas of seasonal vegetation growth and changes in snow depth. After winters with high snowpack, elk delay their vernal migration while in years with lower snowpack and earlier vegetation green-up, elk migrate earlier. There is growing evidence that elk are changing their migratory habits in response to predators: bears, wolves, mountain lions and human hunters. Map depicts the general location and migratory routes of the nine elk herds.

The dynamics of the Paradise Valley herd is highly dependent on private lands and its seasonal migrations have become more constrained. The Northern Herd is the best known and studied herd (along with the Jackson Herd), and the impact of wolves and hunting on population numbers continues to be sharply debated. The Madison Herd summers in and around the Madison Range, and winters in large groups on the high benchlands of the Madison Valley.

 BIOLOGY/ECOLOGY

Elk (Cervus elaphus) are one of the most abundant large mammals found in the GYE, and they are a vital contributor to the ecology of the region: as prey for large carnivores, carrion for scavengers, and consumers of vegetation. Elk are also an economic mainstay for hunting and tourism in the states of Montana, Wyoming, and Idaho. It is not an overstatement that elk define and unify the GYE, both ecologically and culturally.

 While North American’s elk is the same species as Europe’s red deer, the name “elk” is actually the European word for moose. Small wonder that European visitors can get confused on visiting Yellowstone. The species is perhaps better labelled “wapiti,” Shawnee for “white deer” or “white-rumped deer.”

Bull elk weigh about 700 pounds and stand some five feet high at the shoulder; cow elk weigh some 500 pounds and are slightly shorter. Calves are about 30 pounds at birth; born May to late-June, overlapping with periods of peak vegetation green-up and high-nutrition plant phases allowing mothers and calves to build up fat reserves. Elk feed on grasses, sedges, other herbs and shrubs, as well as aspen sprouts and bark, conifer needles, and aquatic plants.

In the fall, bull elk bugle to attract cows and challenge other bulls for dominance. The bugle is not so much a bugle coming from a brass horn as a bellow building to a squeal, terminating in a grunt (listen at https://elknetwork.com/elkfacts/). Dominant bulls gather cows and calves into small groups or harems and then aggressively guard these harems against all comers.

ANTLER MANIA

Bull elk grow massive racks which begin growing in the spring in response to a depression of testosterone levels and lengthening daylight. Yearling bulls grow antlers for about 90 days while healthy, mature bulls grow theirs over a +/- 140 day period. In the later stage of growth, antlers of a mature bull will grow 0.66 inches per day reaching 60” or more in length and weighing some 30 pounds per pair. During much of the summer, “velvet” covers the antlers -- a thick, fuzzy coating of skin, which nourishes and deposits the calcium that forms the antler. Antler growth typically ends in early August, and the bulls begin scraping the velvet off, polishing and sharpening the antler tines in preparation for the coming rut (mating season) in September and October.

Bulls retain their antlers through the winter. When antlered, bulls usually settle disputes by wrestling with their racks. When antlerless, they use their front hooves (as cows do), which is more likely to result in injury to one of the combatants. Because bulls spend the winter with other bulls or with gender-mixed herds, retaining antlers means fewer injuries sustained overall. Also, bulls with large antlers that are retained longer are at the top of elk social structure, allowing them preferential access to feeding sites and mates. Antlers are dropped annually, in March-April, and the process begins anew.

courtesy of arthur middleton

NORTHERN HERD DYNAMICS

The Northern Elk Herd is Yellowstone’s largest herd. Its summer range is centered in the area of the Lamar and Yellowstone River valleys, north of Yellowstone Lake, from Soda Butte to Gardiner, Montana. In winter the herd migrates north outside of the park into the Gallatin National Forest and the lower elevation private lands. With more moderate temperatures and less snowfall than the park interior, the Paradise Valley and surrounds supports large numbers of wintering elk. 

For decades, debate raged over too many elk and the disappearance of willow and aspen from the Lamar Valley and elsewhere. Control of a burgeoning elk population was one of the main arguments for returning the gray wolf as it would provide a year-round predator to control elk numbers and keep them more dispersed across the landscape.

The winter count was approximately 17,000 when wolf reintroduction began in 1995. The number fell below 10,000 in 2003 and 3,914 were censused in 2013 -- the lowest since culling ended in the park in the 1960s. Decreased numbers are attributed to large carnivore recovery (wolf, bears, mountain lion), hunter harvest, and drought-related effects on pregnancy and survival. A total of 4,844 elk were counted in winter 2015 with the expressed hope that the elk decline has stabilized as efforts to maintain wolf numbers have also been implemented (graph).

Winter counts of the Northern Elk Herd in Yellowstone National Park and adjacent areas of Montana, 1960–2016. Counts are not adjusted for elk sightability, and gaps represent years where no official count was conducted. Source: NPS.

There is little doubt that the return of gray wolves have altered elk behavior -- group sizes, habitat selection, movements, distribution, and vigilance. There are some indications that elk–wolf interactions are contributing to a release of willows and other woody vegetation on the northern range. At the same time, the debate continues over the overall condition of the Northern Yellowstone range and its carrying capacity, with several range specialists continuing to point out that the range is seriously overstocked by bison and elk.

DISEASE

Many elk and bison in the Greater Yellowstone Ecosystem have been exposed to the bacterium that causes brucellosis. Brucellosis is a contagious bacterial disease that originated in livestock and often causes infected cows (cattle and elk) to abort their first calves. It is transmitted primarily when susceptible animals directly contact infected birth material. No cure exists for brucellosis in wild animals.

Because of their high densities, elk that are fed in winter have sustained high levels of brucellosis. Winter feeding on the Northern Range stopped more than 50 years ago but winter feeding of elk continues at the National Elk Refuge in Jackson, Wyoming, in addition to 22 Wyoming-run feed grounds. The feed grounds were created in the 1900s to maintain Wyoming’s elk herds and limit depredation as migratory routes from summer range to lower elevation winter ranges became blocked by settlement in the Jackson area. Transmission of brucellosis from feed ground elk, where an average of 30% have tested positive for exposure to the bacteria, was the apparent source of infection in Wyoming cattle in 2004.

Elk, deer, and moose in Greater Yellowstone are at moderate risk for exposure to chronic wasting disease (CWD). This fatal infection, transmitted by animal contact or through the environment, has spread to within 130 miles of the park from the southeast.

FALL HUNTING & SHED HUNTING

The “Welcome Hunter” banners hanging on the front of local taverns, gas stations and restaurants, and the “No Vacancy” signs at local motels in the fall signal the importance of big game hunters, both resident and non-resident, to Idaho, Montana, and Wyoming’s economy. In 2016, big game hunters in Montana spent an estimated $324 million and supported more than 3,300 jobs.

 *Includes license, tags, and processing fees for 2016Shed hunting, the hunting of the cast-off antlers of elk, deer, and moose, has become increasingly popular in recent years, leading to more competition among shed hunters, more conflicts with private landowners from trespass and vandalism, and more impact on big game herds. State Wildlife Management Areas and ranchers are reporting a growing number of incidences. There have even been reported cases where individuals have run antlered elk through trees in early spring in the hope of breaking off antlers.

Currently there are no seasons or required licenses for shed hunting. But that may change as many shed hunters take to the field to gather antlers during the worst time of the year for the animals themselves. Wintering big game animals are very susceptible to any kind of disturbance, especially in the late winter and early spring. At that time of year elk, deer and moose are just trying to hang on until spring green-up, drawing from their diminished body reserves and what little nourishment they can get from surrounding vegetation (like conifer needles and bark). Disturbance from passing motorists, snowmobilers, skiers, dogs, or shed hunters, who intentionally or unintentionally enter areas where elk are bedded down, depletes the little energy the animals have left. This stress and energy depletion leads to sickness and oftentimes death, especially for fawns and calves at this critical time of year.

Ethical shed hunting focuses on not disturbing big game animals on their bedding grounds, respecting public land closures and posted private lands, keeping dogs under control.

Horns or Antlers?

Antlers, found on members of the deer family, grow as an extension of the animal’s skull. They are true bone, are a single structure, and, generally, are found only on males.

Horns, found on pronghorn, bighorn sheep, and bison, are a two-part structure. An interior portion of bone (an extension of the skull) is covered by an exterior sheath grown by specialized hair follicles (similar to human fingernails).

Antlers are shed and regrown yearly while horns are never shed and continue to grow throughout an animal’s life. One exception is the pronghorn, which sheds and regrows its horn sheath each year.

The average, healthy, mature bull has 6 tines on each antler, and is known as a "six point" or "six by six."

  • One-year-old bulls grow 10–20 inch spikes, sometimes forked.

  • Two-year-old bulls usually have slender antlers with 4 to 5 points.

  • Three-year-old bulls have thicker antlers.

  • Four-year-old and older bulls typically have 6 points; antlers are thicker and longer each year.

  • Eleven- or twelve-year old bulls often grow the heaviest antlers; after that age, the size of antlers generally diminishes.

Resources and References

On the Path of Yellowstone’s Elk, Nathan Martin. The Atlantic, June 21, 2016. 

Yellowstone Resources and Issues Handbook. National Park Service U.S. Department of the Interior.

Yellowstone. National Geographic, May 2016

Ticks and what to do about them

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Whitney Tilt, Conservation Chatter, June 2018.

Adult Rocky Mountain wood tick, left, and American dog tick, right. (photos by James Gathany, Centers for Disease Control and Prevention)

With warmer winters, ticks are becoming more and more abundant in the region. Generally “tick season” begins in the spring (weather-dependent) until mid-July, when warmer weather and lower humidity make ticks inactive. Many of our tick species can transmit bacterial, viral, and parasitic diseases to humans and other animals.

Ticks are arachnids (relatives of spiders, mites, and scorpions), having eight legs and no wings. Ticks might go largely unnoticed if not for their habitat of feeding on pets, livestock, wildlife, and ourselves. They are ectoparasites, living outside the host, that feed on blood as their primary nutrition. In the act of getting a blood meal, ticks are capable of transmitting several tick-borne illnesses to people including Rocky Mountain Spotted Fever and Tularemia, among others.

In general, ticks have four life stages: egg, larva, nymph, and adult. Typically, the transition for each stage is to find a host, take a blood meal, drop off the host, shed outer skin (cuticle), and grab onto a new individual, often a totally different host species – up to three different species may provide “habitat” for a single tick. However, some tick species, like the winter tick, stay on one individual through all life stages.

Ticks are attracted to the odor, heat, and breathing of animals and people. Their primary mode of “hunting” involves patiently hanging by their back legs on vegetation, along paths and game trails, for an animal or human to brush up against them. They expertly grab on to their new host and move toward a good feeding spot. Ticks have specialized mouth parts that allow them to bore into skin surfaces and extract blood and other fluids. Once attached, they produce a cement-like substance that glues them in place. In addition, their bodies are flattened so they can lie close to the skin, making it difficult to be removed by an irritated host. On humans, ticks commonly move upward toward the groin, waist area, and scalp.

Tick abundance is highly variable, depending on habitat, abundance of host animals, weather and humidity, and other factors. In Montana, tick season lasts from the onset of warmer weather in the spring until about mid-July when warmer weather and low relative humidity cause the ticks to become inactive.

Seven species of ticks are known to bite and transmit disease to people in the United States including the American dog tick (Dermacentor variabilis) and Blacklegged or deer tick (Ixodes scapularis). The Rocky Mountain wood tick (Dermacentor andersoni) is the primary disease vector in Montana. Adult Rocky Mountain wood ticks feed primarily on large mammals while the larvae and nymphs feed on rodents. Adult ticks are primarily associated with disease transmission to humans. Several other tick species are found in Montana and their distribution, unfortunately, appears to be expanding. The blacklegged ticks that are the primary vectors for Lyme disease are not known to occur in Montana at present.

Other tick species commonly target wildlife species, including rabbits, elk, and moose. Moose can be found covered with the winter or moose tick (Dermacentor albipictus). In wildlife species, ticks do no permanent harm to their hosts, but in some cases disease transmission and sheep number of ticks can cause loss of body condition or death.

 Not all ticks carry disease, and not all tick bites transmit a disease to the host. But it is important to know how to avoid ticks, and what to do in the event of a tick bite. Treat any tick bite with concern (see below).

 Avoiding Tick Bites

Anytime you are outdoors during the tick season, think tick avoidance:

  • Wear light-colored clothing to allow you to see ticks that are crawling on your clothing.

  • Tuck your pants legs into your socks so that ticks cannot crawl up the inside of your pants legs.

  • Apply repellants to discourage tick attachment.

Repellents containing permethrin can be sprayed on boots and clothing and will last for several days. Repellents containing DEET can be applied to the skin but will last only a few hours before reapplication is necessary. Use DEET with caution on children. Application of large amounts of DEET on children has been associated with adverse reactions.

  • Conduct a body check upon return from potentially tick-infested areas by searching your entire body for ticks. Use a hand-held or full-length mirror to view all parts of your body. Remove any tick you find on your body.

  • Parents should check their children for ticks, especially in the hair, when returning from potentially tick-infested areas.

 Additionally, ticks may be carried into the household on clothing and pets. Both should be eamined carefully.

 Removing Attached Ticks

Sooner or later you will likely find a tick on you. If it is crawling around, remove it and wash your hands. If it has become attached:

 
 

1. Use fine-tipped tweezers or notched tick extractor. Where possible, avoid removing ticks with bare hands, using a tissue, paper towel, or latex gloves.

 2. Grasp the tick as close to the skin surface as possible and pull upward with steady, even pressure. Do not twist or jerk the tick; this may cause the mouthparts to break off and remain in the skin. If this happens, remove mouthparts with tweezers.

 3. After removing the tick, thoroughly disinfect the bite site and wash your hands with soap and water. Do not squeeze, crush, or puncture the body of the tick because its fluids may contain infectious organisms. Skin accidentally exposed to tick fluids can be disinfected with iodine scrub, rubbing alcohol, or water containing detergents.

 4. Save the tick for identification in case you become ill. This may help your doctor make an accurate diagnosis. Place the tick in a sealable plastic bag and put it in your freezer. Write the date of the bite on a piece of paper with a pencil and place it in the bag.

 Consult your health care provider if you experience any signs of illness. Early detection and treatment is the best cure for any tick-borne disease.

Diseases carried by ticks in Montana.

Symptoms of tick-borne diseases vary from mild to severe infections requiring hospitalization for care, with the potential for death in rare cases. Early recognition and treatment of infection is important to decrease the risk of serious outcome. Known diseases carried by ticks in Montana are: Rocky Mountain Spotted Fever, Colorado Tick Fever, Tularemia ("rabbit fever"), and Tick-borne relapsing fever. To learn more about the diseases and their symptoms, go to http://fwp.mt.gov/recreation/safety/wildlife/ticks/diseases.html

 Some Resources

About Ticks and Tick Borne Diseases, Center for Disease Control and Prevention. Tickborne Diseases of the United States.

Ticks on Companion Animals, Montana State University Extension


Bear Aware 101

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Whitney Tilt, Conservation Chatter, June 2018

(photo: Montana Fish, wildlife & parks)

In Montana and the Greater Yellowstone, you hear a lot about bears, especially Grizzly Bears. While there is a great deal of information on grizzly bears and how humans should behave in bear country, the following is a summary from a Bear Aware presentation by Steve Primm in June 2018.Bear Aware 101

What makes a Griz inherently dangerous?

Grizzly bears evolved in Eurasia, crossed the Beringia Land Bridge, and came to Northern Rockies some 26,000 years ago. They evolved in open, treeless terrain with a defensive strategy of responding with over-whelming aggression. As compared with black bears, which evolved in North America and trees. Their defensive strategy is to run and climb a tree.

Know Your Bear Identification

Practice to Avoid Bear Contact

Actively work to avoid close-range encounters altogether by maintaining situational awareness. Be attuned to your surroundings, knowledgeable about potential for an encounter; equipped and mentally prepared to stay safe.

Reducing the risk of the “out of nowhere” encounter. Split second encounters with no behavior to observe, no time to identify species.

Elements of Situational Awareness

  • Sight lines (how far can you see?)

  • Wind direction & speed (effects on scent and sound)

  • Masking noises (streams, wind)

  • Habitat/vegetation (feeding, daybeds)

  • Don’t take lack of tracks as a sign of lack of bears

Carcasses

Carcasses, whether from hunting, vehicle strikes or natural causes, are a major source of food for grizzly bears. Dead elk, cows and other large animals are not portable, so grizzly bears will readily defend them with their trademark overwhelming aggression.

  • Don’t approach!!!

  • Be alert for odor

  • Pay attention to scavenger birds (ravens, magpies)

Bear Spray

  • Know how to use it.

  • Practice deploying it before you go into the field

  • Keep it handy (ready for a quick draw, not in your pack or under jackt and straps)

  • Respect expiration dates as old spray does not have range and impact of new spray.

  • If you see a bear within 500 yards, and it’s not running away from you, get your bear spray ready.

Bear Spray or Firearms-which is more effective in an actual bear encounter?

You Never Know Enough

For more information, follow these links at Montana Fish, Wildlife, & Parks

(Photo: Montana fish, wildlife & parks)

Eek! A Spider

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Whitney Tilt, Conservation Chatter, June 2018.

Wolf spider (Photo: Flicker sharing, Thomas Shahan)

Arachnophobia, a fear of spiders, is a common and powerful fear. Many people fear spiders more than other common arthropods like cockroaches, centipedes, and wasps. We all hear stories about the danger of being bitten by black widow, brown recluse, or hobo spiders. All too often, this fear is the result of a lack of knowledge about spiders, and the role they play in the environment.

What’s a Spider?

Spiders are arachnids, in the order Araneae, with four pairs of legs, no antennae, no wings, and only two body regions (compared with insects that have 3 pairs of legs, antennae, often winged, and three body regions). The head and thorax of spiders are combined into a cephalothorax which is attached by a narrow pedicel to an unsegmented abdomen. The abdomen has spinnerets at the posterior end, from which silk for spider webs is spun.

Basic characteristics of arachnids include four pairs of legs (1) and a body divided into two segments: the cephalothorax (2) and the abdomen (3). (source: wikipedia)

 Spiders are predatory, preying on many kinds of insects and other arthropods. Spiders have a pair of hollow pincers, called chelicerae, connected to poison glands -- while all spiders have poison glands, only a few are poisonous to humans. When spiders capture prey, their bite injects venom and digestive fluids, paralyzing their victim. With the prey immobilized, the spider sucks out the innards leaving only an empty shell. Other spiders crush their prey, bathe the tissues with digestive fluids, and crew the entire mass until only a little ball of indigestible material remains. Small wonder spiders are a favorite theme for Halloween and other horror venues.

 A pair of pedipalps on the head, resembling legs, distinguish female spiders, which are also usually larger than males. Females spin silken egg sacs in which they lay masses of eggs. After a period of time, young spiderlings hatch and emerge. Young spiders resemble adults, growing by periodically molting their outer shells 4-12 times to reach the adult stage. If you see what looks like a dead spider, it’s often only the molted shell.

 Spiders Eat as much as Humans?

Spiders prey upon insects in vast quantities. In research recently published in the Science of Nature, Martin Nyffeler of the University of Basel, in Switzerland, and Klaus Birkhofer of Sweden’s Lund University, attempt to put some numbers on spiders’ dining habits. Their conclusion was that there are 25 million tons of spiders around the world and that, collectively, these arachnids consume between 400 million and 800 million tons of animal prey every year. This puts spiders in the same predatory league as humans as a species, and whales as a group. Each of these groups consumes some 400 million tons of other animals annually.

 Spider Identification

Spiders are abundant with some 50,000 known species. Spider identification keys in on such physical traits as the position and number of eyes, the overall shape, length of legs, and form of the spinnerets, as well as behavior, specifically web-spinning or not.

WEB SPINNING SPIDERS

Black Widow Spider

The black widow spider, and its relatives in the genus Latrodectus, are easily recognized by the reddish-to-orange hourglass marking on the underside of the abdomen. Black widow spiders get their name from the fact that the female frequently eats the male after mating, a practice not uncommon to several other species of spiders. In general, a docile, non-aggressive spider, unless the female is protecting the egg sac. The bite is a neurotoxin and very painful. The pain occurs less at the actual bite but rather in the abdomen and limbs. Physiological effects are an accelerated heartbeat, increased blood pressure, breathing difficulties, and paralysis. Although the bite of a black widow is rarely fatal it is important to seek medical attention. Antidotes are commercially available.

Photo (first on left): Female Latrodectus hesperus/western black widow, by Ken-ichi Ueda-wikimedia commons, https://www.inaturalist.org/photos/121, CC BY 4.0.

House spiders

House spiders are among the most common spiders found indoors. They are found worldwide and is common throughout the United States and Canada. Two of their lateral eyes touch each other on each side of the cephalothorax and are well separated from the other four eyes. Female house spiders have bodies which are 1/8 to 3/8 inches long and the abdomen is often covered with dirty whitish or brownish hairs arranged somewhat like chevrons. House spiders spin irregular sheet webs in protected places in the corners of rooms, ledges, windows and under furniture. Unlike black widow spiders, males and females are often observed living together in the same webs. Webs of house spiders often have dead insects entangled in or lying beneath them.

Photo (second on left):  © Tom Meyers.

Orb-weaver spiders

Orb-weaver or garden spiders are generally large, with bodies ½ -1 inch long. They often have conspicuous black, white, yellowish or orange markings. These common spiders are often seen in late summer or fall. They are able to construct large, conspicuous webs with a central hub from which spokes radiate. All this is constructed in less than an hour. The female sits in the hub, waiting to detect movement that signals prey has been captured. After mating, the female seeks a protected place to lay a cluster of eggs, some 300 to 800, which will hatch the following spring.

Photo (3rd from left): orb weaver in the family Araneidae: © 2007 RKD Peterson, courtesy of Montana State University.

Funnel web spiders

Funnel web spiders all have eight eyes about the same size and slightly separated, bodies about ½-inch long, and usually two dark longitudinal stripes on a grayish cephalothorax. The most distinguishing characteristic is a long posterior pair of spinnerets. Funnel web spiders spin flat webs of silk which extend into tubes or funnels into which the spiders retreat for protection, hence the name. The webs are often found in shrubbery near buildings, or in the angles of windows, doors or buildings. They reach the peak of their population in late summer and fall and often enter buildings at that time. Most funnel-weavers die after the first frosts. Winter is passed in the egg stage.

American Grass Spiders (Genus Agelenopsis) are brownish-black with stripes running from front to back with an oblong abdomen with two white stripes broken into sections. The head has a lighter stripe running down the middle, dividing the two dark stripes.

Photo (4th from left) American grass spider: Judy Gallagher – Wikimedia commons;  https://www.flickr.com/photos/52450054@N04/8058527267/, CC BY 2.0.

Aggressive house spider (Hobo)

The aggressive house spider, Eratigena agrestis, is becoming one of the most common spiders in the Northwest. This spider was first reported in the Seattle area in 1930. It is a prevalent spider in basements and in window wells of houses. It rarely climbs vertical surfaces and is usually found only on the ground or lower floors. Experts have called it the aggressive house spider because it bites with little provocation when cornered or threatened. The aggressive house spider is important medically because of its ability to cause necrotic spider bites. (A necrotic bite causes tissue to die.) The aggressive house spider is a long–legged, swift running member of the funnel web spider family. The brown abdomen has a distinctive yellowish chevron pattern. The legs are a uniform brown without the darker brown bands that other nonpoisonous funnel web spiders have.

Photo: Female hobo spider (Eratigena agrestis). Photo by Laurie Kerzicnik, MSU Extension

Non Web-spinning Spiders

Wolf spiders

Wolf spiders are medium to large spiders, and are usually hairy, brown or black, with long legs adapted for running. They have good eyesight – an adaptation for chasing down their prey, paralyzing it and feeding. Webs are not used by wolf spiders. Female wolf spiders carry the egg sac attached to their spinnerets until the eggs hatch. They then carry the young spiderlings about on their backs for a time. Some of the largest spiders encountered in Montana are in this group. This group is very mobile and may be found moving into houses in the fall in search of prey. Wolf spiders are medium to large spiders, and are usually hairy, brown or black, with long legs adapted for running. They have good eyesight – an adaptation for chasing down their prey, paralyzing it and feeding. Webs are not used by wolf spiders. Female wolf spiders carry the egg sac attached to their spinnerets until the eggs hatch. They then carry the young spiderlings about on their backs for a time. Some of the largest spiders encountered in Montana are in this group. This group is very mobile and may be found moving into houses in the fall in search of prey.

Photo (first from the left): Ground wolf spider, Trochosa terricola; © Aleksandrs Balodis, Montana Field Guide

 Jumping spiders

Jumping spiders, like wolf spiders, do not spin webs to capture prey, but rely on quickness and visual acuity. Jumping spiders and wolf spiders have two eyes much larger than the other six, probably an adaptation to help them better see their prey. Jumping spiders are small to medium sized spiders, usually stout bodied, short legged and hairy. They frequently have contrasting black, reddish, or yellowish markings. They are very agile, pouncing and feeding on small insects about the home. They are often seen on screens or near doors or windows.

Photo (second from left): a jumping spider (Platycryptus sp.) © 2007 RKD Peterson, courtesy of Montana State University.

 Crab spiders

Crab or ambush spiders are somewhat crab-like in shape and walk sideways or backward. They are medium sized and often brightly colored, with abdomens that are usually wide at the posterior end. The two front pair of legs are usually longer and stouter than the two hind pair and crab spiders often hold their legs poised to trap insect prey. They have eight relatively small, well-spaced, light colored eyes. Crab spiders are usually found outside in gardens and landscaping where they spin no webs but forage for their prey or lie in ambush on blossoms or other parts of plants. They are able to gradually change colors to match flowers for camouflage. Many species in this family are highly camouflaged. They get their common name from their crab-like behavior, which is generally described as using their front two pairs of legs to manipulate food while moving side to side with their four hind legs.

Photo (third from left): a crab spider in the family Thomisidae, © 2007 RKD Peterson, courtesy of Montana State University.

Brown recluse spiders

Brown recluse spiders are easily recognized by a key characteristic: six eyes arranged in three pairs forming a semicircle. The fiddle on the top side of the spider is not always clear and found in many other spiders. Most other spiders have eight eyes variously arranged. Adult female brown recluse spiders are about ½-inch long (legs excluded); males are somewhat smaller. Both female and male brown recluse spiders can bite people and inject venom. Individuals react differently to bites. A stinging sensation is usually followed by intense pain. A small blister arises and a large swollen area around the bite becomes congested and swollen. While bites of the brown recluse are generally not fatal, they result in a local necrotic lesion that heals slowly, leaving an ugly scar. There are other spider bites that give a similar reaction, and these are often misdiagnosed by well-meaning physicians as brown recluse spider bites. Presently Brown Recluse spiders are not documented in Montana and the Northern Rockies.

Daddy Longlegs (Harvestman)

Daddy longlegs, also known as harvestman, are not spiders, but in the order Opiliones comprising more than 6,000 species of aranchnids. Their extremely long narrow legs and small bodies, that appear as a single segment, are characteristic. The body is a simple oval, and it’s usually hard to tell where the “head” ends and the segmented “abdomen” begins. Daddy longlegs are harmless, lacking fangs and do not produce venom. Some species have mouthparts that form an enlarged pincer-like tooth that might slightly pinch, but none bite. Daddy longlegs resemble cellar spiders (Pholcus phalangioides), a long-legged spider, which have legs 5-6 times longer than the body and a distinct “waist” betwen the cephalothorax and abdomen. Another way to distinguish living specimens of these two is from their web-spinning habits. Daddy longlegs do not spin webs and are seen running agilely over the ground; in contrast, cellar spiders do spin webs, where they are almost exclusively found. If they are knocked off their web, cellar spiders move clumsily on the ground.

Photo: Harvestman, © Donna Brunet, courtesy of Missouri Department of Conservation

Management- What to do about spiders?

Spiders are beneficial, preying on insects, so control measures should only be used in situations where they become intolerable – for instance, where black widow or other spiders pose a threat to individuals or pets. A broom or vacuum cleaner used to dislodge and move outside or crush spiders will suffice. Spiders found outside under eaves and in corners of residences can be removed/relocated by use of a broom. Keep spiders out of your home by:

  • Weather-strip and caulk around doors, windows, and utility lines.

  • Fill in cracks in siding and around the foundation; reset loose bricks and siding.

  • Keep debris and wood piles away from buildings.

  • Inspect firewood for spiders and egg sacs before bringing indoors.

  • Reducing clutter in storage spaces as boxes and other objects stored in undisturbed basements, crawlspaces, garages, and closets provide hiding places.

Protect yourself from spider bites when working around potential spider habitats by wearing gloves when gardening, moving wood piles or debris, or placing your hands into dense vegetation. Wear long-sleeved shirts and pants if you work around crawlspaces or cedar-shake shingled rooftops where spiders can hide.

Spider Sniffing

Ever wondered how many spiders might be watching you? If you have a flashlight and darkness, you can spot them by the green glow of their eyes.  

Many animals that hunt at night have an iridescent layer behind their retinas called a tapetum, including cats, dogs, racoons and some birds. It improves their night vision, and also causes “eyeshine.” Most spiders have eight eyes and four of those eyes have tapetum, so go find them. 

To go spider sniffing, hold a flashlight level with your eyes. Spider eyeshine is returned at a relatively narrow arch so this flashlight position is key to spider detection. Sweep the light across outside lawn and other dark spider-lurking spots. If you see a bright point of eerie green light, that’s your flashlight beam reflecting off a spider’s eyes.  

Arachnophobes, meanwhile, should consider this: without spiders, there would be an awful lot more other creepy-crawlies around.

 Sources

Primary source: Spider Identification and Management.Montana State University Extension, MT199210, 4 pages.

“Spider Bites”, Economist, March 18, 2017.

Edward John Bechinski, Dennis J. Schotzko, and Craig R. Baird.  2010. Spiders around the home and yard. Idaho Extension Service. 28 pages