Eek! A Spider

/

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

 

When is a Weed a Pest?

/

Houndstongue (Cynoglossum officinale)

When It’s Invasive

A species -- plant, fish, insect, mammal, bird, or disease -- is invasive when it is both nonnative to the ecosystem in which it is found and capable of causing environmental, economic, or human harm. Invasive species often compete so successfully in new ecosystems that they displace native species and disrupt important ecosystem processes. Considered by scientists as one of the single largest threats to our nation's natural resources, invasive species:

  • Decrease biodiversity

  • Further imperil endangered and threatened species. Invasive species are considered the second leading cause (after habitat loss) of animal population decline and extinction worldwide.

  • Displace native plants that wildlife and fish depend on for food.

  • Increase soil erosion and can cause major damage to streams and other wetland areas that provide habitat for native fish, plants, and animals.

  • Intensify the frequency and risk of wildfires.

  • Reduce agricultural production and property values.

Canada Thistle (Cirsium arvense)

 When It’s Misbehaving

A weed is a plant out of place. It is a plant growing where it is not wanted by humans. Ralph Waldo Emerson considered a weed “a plant whose virtues have yet to be discovered,” i.e., a plant in need of a publicist.

 For land managers, a weed is a plant that interferes with the management objectives of a given area at a given point in time. In Montana, a weed is elevated from this overly broad category to “noxious” when they are plants of foreign origin that can directly or indirectly injure agriculture, navigation, fish or wildlife, or public health. Currently there are 30+ plant species on the statewide noxious weed list in Montana that collectively infest some 7.6 million acres. In addition, counties can add additional species of concern.

 The concern about “foreign origin” is not a form of floral xenophobia, but rather recognition of a pattern that alien species, inadvertently or otherwise imported into North America, are generally regulated only by abiotic factors (climate, fire, flooding, etc.) which are insufficient to keep their populations in balance. Biotic factors, such as insect predators and plant pathogens, that evolved with the species in their native lands are typically not present, and therefore not a control. Spotted knapweed, yellow starthistle, purple loosestrife and leafy spurge are four examples of plant species that are both exotic and invasive.

  • The impacts caused by noxious weeds, like that of invasive species in general, are economic and ecological:

  • Potential to dominate plant communities, form monocultures, displace native and desired forage species.

  • Alter water cycles and cause erosion: for example, areas infested with spotted knapweed incurred 56% higher runoff and 192% higher sediment yield compared to those dominated by native bunchgrass in western Montana.

  • Cause economic loss: for example, cost of leafy spurge to grazing lands and wildlands in the upper Great Plains including the states of Montana, North and South Dakota, and Wyoming is estimated at $129.5 million annually. Closer to home, consider the extra time and effort for wranglers to remove houndstongue and burdock from horses.

The rate of introduction and spread of noxious weeds has increased dramatically over the past 150 years with increases in human activities, trade, and commerce. For example, spotted knapweed was first recorded in the state in the early 1920’s. Since that time, it has spread to infest more than 4 million acres in the state, and continues to spread. 

So What to Do? 

  • Know your weeds. Most weeds are spread as a result of ignorance or non-action. For example, resist the temptation to "pluck and chuck" the velcro-like seeds of houndstongue as that helps spread them.

  • Prevent infestations of new noxious species. It is relatively easy to control and even eradicate small populations of noxious weeds. Best yet to prevent the introduction of new species and populations.

  • Control spread of existing noxious weeds. Clothing, horses, and off-road vehicles are three effective vectors for transport of noxious weed seeds from an existing population to a new one.

  • Keep an eye on the rest. Guilty of being non-native immigrants (like many residents of Montana), the vast majority of weeds are part of the landscape and their behaviors don’t rise to the level of harm -- which raises the last point.

  • Know what’s noxious, and what is not. Increasingly there is ample evidence that herbicide applications in the name of weed control can cause more harm than good when the spray wand is in the hands of applicators who don’t recognize that every broad-leaved plant is not a weed. Fields that once abounded with prairie smoke, anemones, and other wildflowers, have been reduced to stands of non-native pasture grasses. In the name of controlling noxious weeds, we are attacking our native plant life.

Whitney Tilt- June 2019

A Legacy of Fences

/

Robert Frost observed that “Good fences make good neighbors” (Mending Wall).

 FENCES & WILDLIFE

 We live with fences. They define property, confine livestock, and keep our children and pets safe. They delineate public and private, and control trespass. Thousands upon thousands of miles of fence, mostly comprised of barbed wire, literally define the western United States, squaring up the landscape and turning space into place (See Open Range Box below). 

For wildlife, fences are barriers to negotiate at best and lethal hazards at worst. Elk, deer, and pronghorn face fences on their daily movements to water and forage, and more fences on their seasonal migrations between summer and winter ranges. For grouse, swans, and other wildlife, fence lines are often undetected until they break wings and necks. When wildlife meet the wrong kind of fence, it results in injured or dead wildlife. It also translates into lost time and increased costs to the landowner as they are forced to mend broken fences. Robert Frost’s little known poem with the well-known line above, also contains the lines: Before I built a wall I’d ask to know/What I was walling in or walling out/And to whom I was like to give offense.

Figure 1. Pronghorn entangled in fence. Photo by Steve Primm (note: animal was alive and released).

Fences, coupled with human development and loss of habitat, are a major challenge for the conservation and management of wildlife. Most wildlife are capable of negotiating a properly constructed and maintained fence. A poorly designed and maintained fence, however, is a problem fence. Problem fences typically share one or more traits:

  • too high to jump and/or too low to crawl under;

  • have loose wires and/or wires spaced too closely together;

  • are difficult for fleeing animals or birds to see;

  • create a complete barrier

 A 2006 study by Utah State University examined wildlife mortality in northeastern Utah and northwestern Colorado along more than 600 miles of fences (Harrington and Conover 2006). They found an average of one ungulate tangled for every 2.5 miles of fence per year. Most animals died by getting caught in the top two wires while trying to jump a fence, and juveniles are eight times more likely to die in fences than adults. They also confirmed that woven-wire fence (aka “sheep fence”) topped with a single strand of barbed-wire was the most lethal fence type.

 COOPERATION & ACTION

 While there is a great deal more that can be said on wildlife-fence interactions, there is good news. State wildlife agencies, ranchers, conservation organizations, and others have joined forces to design and locate effective fences with wildlife in mind. Working together, ranchers and wildlife interests (commonly one and the same) have come up with new fence designs where top wires are low enough for adult animals to jump, bottom wires are high enough for wildlife to crawl under, and middle strand placement minimizes the chance of tangling (Figure 2). In practice these designs have been found to control cattle in most situations and allow for easier wildlife passage. They also prove more cost-effective to build and maintain as there is less need to repair.

Figure 2 (Paige 2012)

  • A top wire or rail preferably no more than 40" and a maximum of 42" above the ground;

  • At least 12" between the top two wires;

  • A bottom wire or rail at least 16" and preferably 18" above the ground;

  • Smooth wire or rail for the top, smooth wire on bottom;

  • Preferably, no vertical stays. If used, consider stiff plastic or composite stays, or regularly maintain wire stays that are easily bent;

  • Posts at 16.5-foot intervals;

  • Gates, drop-downs, or other passages where wildlife concentrate and cross.

 The location of fences remains an important consideration, both for visibility and other landscape considerations, such as slope (Figure 3).

Figure 3 (Paige 2012)

For both wildlife and landowners alike, a policy that all new fence construction incorporate wildlife-friendly designs translates into less fence repair and less stress and injury to wildlife. Minimize the use of barbed wire (the main culprit of wildlife and livestock injury), and use alternative, such as smooth high-tensile wire where possible. In addition, in areas of high wildlife look to design crossing structures such as the take-down sections, crossing fences, or gates to allow easier passage of wildlife along well-travelled corridors. Just as importantly, on public and private lands we can work together to remove unwanted fencing.

OPEN RANGE

Cole Porter’s song “Don’t Fence Me In” (1934) could be retitled “Open Range.” Most of Montana, along with many other western states, still classify much of their land as open range, requiring landowners to “fence out” neighboring livestock. Additionally, a livestock owner is not liable for trespass or damage if a property is not adequately fenced. Montana’s open range law applies to cattle and horses while sheep, goats, and other livestock must be fenced in. Incorporated towns and subdivisions may create “herd districts,” closing their range and placing the responsibility for “fencing in” on the stock owner. In practice, many livestock operators fence their property and pastures to better manage their livestock and range resources. Where their pastures adjoin federal lands, livestock owners are also responsible for preventing their livestock from illegally trespassing on those lands (Mont. Code Ann. § 81-4-301).

Figure 4. Elk crossing fence at West Creek Ranch.

RESOURCES

Paige, C. 2012. A Landowner's. Guide to Wildlife Friendly Fences. Second Edition. Private Land. Technical Assistance Program, Montana Fish, Wildlife & Parks. http://fwp.mt.gov/fwpDoc.html?id=34461

Harrington, J.L., and M.R. Conover. 2006. Characteristics of ungulate behavior and mortality associated with wire fences. Wildlife Society Bulletin 34(5) 1295–1305.

 

Whitney Tilt- July 2017 

Hemlock in our Midst

/

Conium maculatum, from Flora of the Yellowstone

Tall, Leafy… and DEADLY

A rich diversity of plants, native and invasive, thrive in southwest Montana’s varied landscapes. Some may be edible, making for a nice addition to a trailside salad, or they can land you in the ER if you’re hasty with identification. Here’s one to look out for.

Species: Poison hemlock (Conium maculatum), Apiaccae (Parsley Family)

Flowers: June – August

Habitat: Moist soils, disturbed areas, along roads, ditches & fields

Description: A native of Eurasia that is rapidly establishing itself across the region, all parts of this tall, stout plant are extremely poisonous. Poison hemlock is notorious for the execution of Socrates in ancient Greece—even small amounts can be deadly. The plant looks superficially similar to other members of the parsley family, such as wild carrot (Daucus carota), that one might nibble for a bit of parsley flavoring. However, conium, from the Greek konas, means to whirl, and vertigo is one of the symptoms of ingesting the plant. Maculata means “spotted”; purple-spotted stems are a good field mark, but avoid all parsley-like species unless you are an expert in distinguishing them. Look for poison hemlock in moist soils and disturbed areas, and along roads, ditches, and fields, from the plains to montane.

Conium maculatum, from Flora of the Yellowstone, Photo courtesy of JD Carr.

Whitney Tilt - July 2017

WHAT’S ALL THIS ABOUT WEEDS?

/

North Fork Landowners Association

Today in southwestern Montana, certain weeds have earned notoriety. Blacklisted as “noxious”, “invasive”, and “alien,” they are depicted on wanted posters as outlaws like Jesse James and Ma Barker. At the same time, we are surrounding on a daily basis with non-native species that have become part of our landscape.

Perhaps the best definition of a weed is a plant growing where it is not wanted… at least not wanted by humans. It is a plant in need of a publicist.

Every year more “aliens” are added to our watch lists. With the specter of climate change and increased globalization, where should our battle against weeds go? Emma Marris in the Rambunctious Garden notes that we have grown fond of clinging to fragments of virgin landscapes and intact ecosystems. But like slivers of soap, they shrink and slip through our fingers. Rather than mourn the passing of “pre-human” nature, however, Marris takes a more optimistic approach that today’s nature, while decidedly not pristine, is abundant and it should be embraced for what it is rather than some fossilized view of nature past.

So what to do about weeds in and around southwest Montana?

First, know the bad actors that truly impact the land and its use. Leafy Spurge, Common Tansy, Canada Thistle, and Spotted Knapweed are four examples of what being noxious is all about -- they can spread rapidly, impact vegetation and soils, and alter how the land can be utilized. Species like Burdock and Houndstongue are certainly a nuisance to livestock, wildlife, and pet owners.

Second, know the best methods of control. Driving by field after field of pastures made a monoculture of Smooth Brome remind us of the dangers of indiscriminate herbicide use. Arguably a field of a variety of native and non-native grasses and forbs, including the so-called invasives is better for biodiversity than a sea of smooth brome.

Guilty of being intentional or accidental immigrants, the vast majority of non-native plant species become part of the landscape and their behaviors don’t rise to the level of harm -- which raises a vital concern. Weed spraying programs can cause more harm than good when the spray wand is in the hands of applicators who don’t recognize that every broad-leaved plant is not a weed. Fields that once abounded with prairie smoke, anemones, and other wildflowers, have been reduced to stands of non-native pasture grasses. In the name of controlling noxious weeds, we are attacking our native plant life with potential profound impacts on pollinators, birdlife, and soil health.

A noxious, invasive lineup: Tansy, Spotted Knapweed, Houndstongue, Leafy Spurge

Whitney ilt - July 2017

Health Benefits of Being Outdoors

/
“… an eye made quiet by the power
Of harmony, and the deep power of joy,
We see into the life of things.
”
— William Wordsworth, Lines Written a Few Miles Above Tintern Abbey (1798)
“It is a scientific fact that the occasional contemplation of natural scenes of an impressive character, particularly if this contemplation occurs in connection with relief from ordinary cares, change of air and change of habits, is favorable to the health and vigor of men and especially to the health and vigor of their intellect…  ”
— Frederick Law Olmsted, Yosemite Valley and the Mariposa Big Tree Grove (1865)

 When Wordsworth, Olmsted and others offered their observations, there was little in the way of supporting research. Today, motivated by the health issues of obesity, depression, ADHD, and pervasive nearsightedness, a growing body of research documents how spending time outside, and being active, secures a wealth of potential benefits, from increasing our immune response to improving short-term memory (Williams 2016).

 As we enter the 21st Century, half the human population lives in cities. This urbanized humanity is forecast to rise to 70 percent with the next few decades. Spending up to seven hours per day staring at screens of their mobile devices and computer screens (exclusive of school time!), today’s children are likely to spend half as much time outdoors as their parents.

 Richard Louv (2012) cautions that our growing disconnect with nature, our “nature-deficit disorder,” threatens our health, our spirit, our economy, and our future stewardship of the environment. He observes that the more high-tech our lives become, the more nature we need to achieve natural balance, and that the mind/body/nature connection (vitamin N), will enhance our physical and mental health.

Watching people at play outdoors.

 Simply stated, being outdoors is good for our mental and physical health. An increasing body of research suggests that people benefit from a “minimum dose of nature.” Here are some insights:

 1) Getting Outdoors [typically] Increases Physical Activity.  While you can be active at home or at the gym, we tend to be more active outdoors, from raking leaves to taking a hike. This is particularly true with children who commonly spend a good deal of time indoors, sitting down, and sedentary with their electronic media. One study, which tracked the activity of 1,000 children, found that the children were more than doubly active when they were outside (Harvard Health Letter, 2010).

 As Lee (2017) observes, “Think about how much of your time indoors is spent remaining relatively motionless, such as sitting in front of a computer or in a meeting, texting on the toilet or staring at the Kardashians on television. Can you really do the same outdoors without feeling odd or being arrested? Being outdoors in many ways forces you to be more active. Trails make you hike. Hills and mountains make you climb them. Bigfoot makes you run.”

 “If outdoor activity encourages more activity, then it is a good thing,” says Jacqueline Kerr, a professor at the University of California, San Diego. After all, “despite the fitness industry boom, we are not seeing changes in national physical activity levels, so gyms are not the answer” (Reynolds, 2013).

 2) Sunshine & Vitamin D. Vitamin D helps defend us against everything from cancer and osteoporosis to heart attacks and stroke. Many of us who spend more and more time indoors don't have enough vitamin D. Getting outdoors in the sunshine on a regular basis and exposing our arms and legs for 10-15 minutes will give us a beneficial dose of the “sunshine vitamin.”

 A note on sun screen. While sun screens are important to protect our skin from the harmful effects of ultraviolet light, they also inhibit production of Vitamin D since they work to block ultraviolet B (UVB) light, which causes sunburn but also the generation of vitamin D. To strike a balance, experts recommend we get our Vitamin D producing sun for short periods, while using sun screen when out for extended periods, particularly during the middle of the day.

 3) Nature Improves Mental Health. Research suggests that when we get outdoors in a natural setting, city park or wildness, our minds get an escape from the busywork, slow down, and simply enjoy the surroundings. The experience restores our energy and sharpens our mental performance. A study conducted by the University of Queensland (2016) demonstrated that 30 minutes of nature exposure per week reduced depression prevalence by up to seven percent.

 Researchers at Stanford University (Jordan 2015) found that people who walk for 90 minutes in nature, as opposed to high-traffic urban settings, showed decreased activity in a region of the brain associated with a key factor in depression. City dwellers were found to have a 20 percent higher risk of anxiety disorders and a 40 percent higher risk of mood disorders as compared to people in rural areas. People born and raised in cities are twice as likely to develop schizophrenia.

 4) Boost to Concentration. Playing off ADHD, attention deficit hyperactivity disorder, Richard Louv (2006) coined the term "nature-deficit disorder" in Last Child in the Woods. In fact, research has found that children with ADHD seem to focus better after being outdoors. A University of Illinois (2008) study found that children with ADHD scored higher on a test of concentration after a walk through a park than after a walk through a residential neighborhood or downtown area.

 5) Helps Prevent Nearsightedness. Nearsightedness (myopia) has been on the rise in children in recent years. In parts of the world where people spend most of their time indoors, rates of myopia have skyrocketed. By adulthood, one in three people in the United States has myopia. In parts of Asia, more than 95 percent of children and teens may wear glasses to correct for myopia. A Canadian study (Science News 2016) found that for one additional hour of outdoor time per week, the risk a child will develop myopia drops by about 14 percent. A systematic review looked at 25 recently published studies and found increased outdoor time to be protective for the development of myopia – about an extra 1.25 hours per day compared with control/baseline time spent outdoors reduced the risk of onset of myopia by 50%. Time outdoors had a stronger protective effect in children aged 6 years compared with kids aged 11 to 12 years enrolled in longitudinal studies (Brien Holden, 2017).

 Forest Service Literature Review. The U.S. Forest Service Ecosystem Service Team in Portland, Oregon worked to translate scientific findings from a literature search. Their findings:

  • Researchers are demonstrating the positive effects of nature on blood pressure, cholesterol, outlook on life, and stress reduction. It has also proved beneficial to those with attention deficit disorder (Kuo and Taylor 2004).

  • People who walk 15 to 30 minutes a day are healthier than people who don’t—they have fewer diseases, are less likely to get cancer, have a lower risk of heart attack and stroke, and have better bone density.

  • Walking improves digestion and decreases the risk of intestinal cancer, reduces risk of type II diabetes, and reduces insulin dependency of diabetics. Walking recalibrates energy/fat storage so the body becomes more efficient and trim. Walking helps the kidneys, the lymphatic system, and the joints. It also diminishes some types of arthritis (Hartman 2006).

  • Research at Duke University in 1999 found that a brisk 30-minute walk three times a week was more effective in reducing depression symptoms than Zoloft® alone or Zoloft® and walking, and walkers were less likely to have a recurrence of depression (Hartman 2006).

  • “Parks and other natural environments are a fundamental health resource, particularly in terms of disease prevention” (Maller et al. 2008).

  • Spending time in nature also has been linked to longevity and decreased risk of mental illness in studies in Scandinavia and the Netherlands (De Vries et al. 2003, Grahn and Stigsdotter 2003).

  • Health benefits of nature may also have relevance to injury prevention and control, diabetes, asthma, arthritis, musculoskeletal conditions, and other maladies, including cancer (Li 2009).

  • A Japanese study of men and women on a 3-day/2-night trip to a forest included short walks each day (Li 2009). Blood and urine samples were tested during and following the trip. Results suggest that a monthly trip in nature could provide maintenance levels of cells that work to prevent cancer generation and development, among other benefits.

  • Breathing in antimicrobial compounds found in the essential oils of trees increases relaxation and improves stress management resulting in increased vitality and less anxiety, depression, and anger. It also may decrease risk of psychosocial-stress related diseases.

 So the next time that someone tells you to “take a hike,” thank them and get outside.

 References

Brien Holden Vision Institute. 2017. Time Spent Outdoors – How Effective in Myopia Prevention and Control? https://www.brienholdenvision.org/news/item/102-time-spent-outdoors-how-effective-in-myopia-prevention-and-control.html

 De Vries, S.; Verheij, R.; Groenewegen, H.; Spreeuwenberg, P. 2003. Natural environments—healthy environments? An exploratory analysis of the relationship between green space and health. Environment and Planning. 35(10): 1717–1731.

Ferguson, Jill. 2017. 5 benefits of being outdoors. June 10, 2017. (https://www.huffingtonpost.com/entry/5-benefits-of-being-outdoors_us_5938266ce4b014ae8c69dce0)

Grahn, P.; Stigsdotter, U.A. 2003. Landscape planning and stress. Urban Forestry and Urban Greening. 2: 1–18.

 Hartmann, T. 2006. Walking your blues away: how to heal the mind and create emotional well-being. Rochester, VT: Park St. Press. 112 p.

 Harvard Health Letter. 2010. A prescription for better health: go alfresco, July, 2010. (https://www.health.harvard.edu/newsletter_article/a-prescription-for-better-health-go-alfresco)

 Jordan, Rob. 2015. Stanford researchers find mental health prescription: Nature. Study finds that walking in nature yields measurable mental benefits and may reduce risk of depression. https://news.stanford.edu/2015/06/30/hiking-mental-health-063015/

 Kuo, F.; Taylor, A. 2004. A potential natural treatment for attention-deficit/hyperactivity disorder: evidence from a national study. American Journal of Public Health. 94(9): 1580–1586.

 Lee, Bruce Y. 2017. 10 Health Problems That the Outdoors Can Help Prevent And Treat. Forbes, January 8, 2017

 Li, Q. 2009. Effect of forest bathing trips on human immune function. Environmental Health and Preventive Medicine. 15(1): 9–17.

 Louv, Richard. 2006. Last Child in the Woods- Saving Our Children from Nature-Deficit Disorder. Algonquin Books of Chapel Hill. 334 pages.

 Louv, Richard. 2012. The Nature Principle- Reconnecting with Life in a Virtual Age. Algonquin Books of Chapel Hill. 330 pages.

 Maller, C.; Townsend, M.; St. Leger, L.; et al. 2008. Healthy parks, healthy people: the health benefits of contact with nature in a park context. Melbourne, Australia: Deakin University and Parks Victoria.

 PerfectMind Blog. 10 Health Benefits of an Outdoor Lifestyle. http://blog.perfectmind.com/10-health-benefits-of-an-outdoor-lifestyle

 Reynolds, Gretchen. 2013. The benefits of exercising outdoors. New York Times, February 21, 2013. https://well.blogs.nytimes.com/2013/02/21/the-benefits-of-exercising-outdoors/?_r=1

 Oosthoek, Sharon. 2016. Outdoor time is good for your eyes. Science News, December 20, 2016. https://www.sciencenewsforstudents.org/article/outdoor-time-good-your-eyes

 University of Illinois at Urbana-Champaign. 2008. A Walk in the Park Improves Attention in Children with ADHD. https://www.sciencedaily.com/releases/2008/10/081015120742.htm

 University of Queensland. 2016. Dose of Nature is just what the doctor ordered. https://www.uq.edu.au/news/article/2016/06/dose-of-nature-just-what-doctor-ordered

 U.S. Forest Service. Health and Wellness Benefits of Spending Time in Nature. https://www.fs.fed.us/pnw/about/programs/gsv/pdfs/health_and_wellness.pdf

 Wallace, Jennifer. 2017. Why it’s good for grown-ups to go play. Washington Post,  May 20, 2017 https://www.washingtonpost.com/national/health-science/why-its-good-for-grown-ups-to-go-play/2017/05/19/99810292-fd1f-11e6-8ebe-6e0dbe4f2bca_story.html?utm_term=.865e78b83c9b

 Williams, Florence. 2016. This is your brain on nature. National Geographic (January 2016) https://www.nationalgeographic.com/magazine/2016/01/call-to-wild/

 William, Florence. 2017. The Nature Fix. W.W. Norton & Company. 304 pages. 

Whitney Tilt - April 2017