Columbia Black-tailed Deer – Crepuscular Cud Chewer 

The word ‘deer’ is an irregular noun. It is used for both single and multiple animals. Deer are also crepuscular, active during twilight hours.

Of the six subspecies of mule deer living in California, Nevada County is home to two; the California mule deer (west side of Sierra Nevadas to the southern coast) and the Columbia black-tailed deer (Northern California through the Pacific Northwest). Since black-tailed deer are the species roaming through my yard, they are the main subject of this article.

History & Range

The Columbia black-tailed deer is also known by the names; Pacific buck, Columbian deer, coast black-tailed buck, and black-tailed deer. It is a subspecies of Mule deer and will cross-breed with the California mule deer and Rocky Mountain mule deer where habitats overlap.

In 1846, an Oregon Trail traveler noted black-tailed deer as far west as Wyoming. Today their range is smaller. It includes northern California, Oregon, Washington, some parts of coastal and interior BC as well as the Alaskan panhandle.

With the 1934 Taylor Grazing Act, the organization that eventually became known as the Bureau of Land Management was tasked with managing public forage lands for cattle and wildlife. It became one of the numerous organizations cooperating across state and county lines to track and manage these wild animals. ( US Forest Service, California Department of Fish and Wildlife and U.S. Department of Agriculture.)

Identification

  • large ears, relaxed
  • short, stubby tail
  • loose tail position
  • winter coat color – silver gray
  • cap / patch of fur at top of head
  • thicker stripe of dark fir on tail than Mule deer

Behavior

Except for breeding season (November – December), does and bucks live in separate groups. 

Female groups of related individuals are led by a dominant (alpha) animal, usually the eldest mother. She chooses foraging and birthing grounds. The alpha female is usually the first to mate during mating season and she generally chooses to stay close to her mother’s territory, leaving it only if forced.

 

Males leave their mothers between a year-and-a-half and eighteen months old to seek bachelor groups.

New antlers (bone protrusions) are grown each spring and shed every winter. 

Antlers are grown out with a ‘velvet’ covering, a living structure with blood vessels. Once it dries and antlers harden, bucks rub them against trees to remove the velvet. A buck’s age is reflected in the number of forks. Antlers are used for sparring and determining social position as well as for mate competition. 

 

Communication

Communication methods include vocalizations, scent, and pheromones. Glands between the toes, and near the knees (hock) create trail marking and individual recognition signals while glands outside the lower legs produce alarm scents. 

Large, independently moving, ears enable sensitive hearing. 

Migration

In California, at higher elevations, some herds of black-tailed deer migrate. Locations of forage food and snow levels determine their movements.

In Nevada County, below Nevada City, seasonal herd movements do not cover great distances.

Life Span

The black-tailed deer life span is approximately 7 years (in the wild), reaching sexual maturity between 1-2 years.

Reproduction

Males are polygynous, they’ll mate with multiple females.

Female gestation lasts between six to seven months, with fawns born May – June.

For the first week after birth, fawns have no scent. This allows the mother to leave her babies to replenish her body weight and produce adequate amounts of milk for her young.

Caution: Mothers with fawns view humans as predators.

Diet

Like cattle, sheep, giraffe, goats, and antelope, deer are cud-chewing grazers. With teeth and mouthparts specialized for breaking down cellulose as well as a digestive compartment housing bacteria necessary to turn plant material into protein, volatile fatty acids as well as vitamins B and K, deer spend the early morning and dusk hours grazing and afternoon and evening hours, bedded down, regurgitating, and giving food a second chew. 

Spring and winter diet includes;

  • California Buckeye
  • Douglas-fir
  • Fern
  • Lichen
  • Huckleberry
  • Poison oak
  • Grasses
  • Cedar
  • Bark & buds

Late spring and fall diet includes;

  • Grasses
  • Fruit (blackberry & apple)
  • Fireweed
  • Pearly everlasting
  • Forbs
  • Rosehips
  • Salmonberry
  • Salal
  • Maple trees
  • Acorns

Rumination – Chewing Cud

Grazer gut bacteria often match soil microbes. Eating and defecating perpetuate healthy regeneration cycles for both plants and animals.

Grazing to Heal the Earth – Grasses & Ruminants | 3:14 Chewing Cud

Predators

  • Mountain lion
  • Coyote
  • Eagle
  • Bear
  • Humans

Deer Hunting Industry & Income Generation

In California, Deer hunting permit sales generate around $450 million dollars annually, attracting between 165 – 200K hunters. 

 

California Department of Fish and Wildlife Twenty-five Year Dear Population Estimates

Issues Affecting Deer Habitat & Populations

  • Habitat loss & fragmentation
  • Herbicide use on private and public lands
  • Timber & reforestation practices – biomass, hardwood removal, clear-cutting & thinning
  • Livestock grazing
  • Prescribed fire & fire suppression & wildfires
  • Reservoirs
  • Ski areas, golf courses & agricultural land uses
  • Poaching
  • Changing weather patterns including severe winters and drought
  • Highways and roads (1.5 million deer and vehicle collisions/year – Insurance Institute for Highway Safety)
Click image to purchase or see more Life on the Creek art
click image to download FREE coloring sheet

 

 

If you liked this post, you may also like Mountain Lion – Fragmented Power Pouncer.

 

Resources:

Bay Nature – Are Deer Twins Common?
California Department of Fish and Game – Assessment of Mule and Black-tailed Deer Habitats and Populations in California – 1998 [PDF] California Department of Fish and Wildlife –
Mule Deer
California Department of Fish and Wildlife – Deer Management Documentation
California Department of Fish and Wildlife – Deer Population Estimates
California Department of Fish and Wildlife – Private Lands Management
iNaturalist – Columbian Black-tailed Deer
Journal of Wildlife Disease – Hair-Loss Syndrome in Black-tailed Deer of the Pacific Northwest
Mule Deer Foundation
Mississippi State University | Deer Ecology & Management Lab – Antler Growth Cycle
National Park Service – Pacific Coast Science and Learning Center – Black-tailed Deer Researchers, References & Links
Sierra Club – 
Largest Mule Deer Migration Ever Recorded
Western Hunter – Black-tailed deer of California
Wikipedia – Ruminants

Mule Deer Migrations

Nevada & Texas Deer Herd Management

 

Mountain Lion – Fragmented Power Pouncer

History

Wikipedia commons

Since the late 1850’s, North America’s big cat has been known as the mountain lion. Early Spanish explorers called it ‘gato monte‘ which means cat of the mountain.

Latin America calls it puma (powerful) which comes from the 16th century Peruvian Quechua language.

Because of its wide range, diverse habitats, and the span of human cultural locations, this animal is known by many other names including; cougar, panther, and catamount.

Geographic Habitat

California’s current mountain lion population is between 4,000 – 6,000 animals.

Closely related to the house cat, these big cats are adaptable to a large variety of ecosystems. In the Nevada County portion of the Sierra Nevadas, they like dense underbrush and rocky outcropping habitats.

Highly territorial, males generally claim a 150 square mile area that may vary depending on terrain and prey availability. Females have smaller territories, about half the size, and they stay in the general proximity of their mothers.

 

“Wherever you see deer in the state, there’s also going to be cougars.”  – Chris Wilmers, Wildlife Ecologist, UC Santa Cruz

Characteristics

  • Mountain lions are the world’s fourth-largest big cat weighing between 150 – 200 lbs. (1. Siberian Tiger | 900 lbs. 2. African Lion | 600 lbs. 3. Jaguar | 300 lbs.)
  • While the mountain lion is an apex predator, it will sometimes give ground to black bears.
  • These cats can swim, although this is not a favorite activity.
  • Hunting mostly during twilight hours and at night, mountain lions are ambush predators. They sit-and-wait, often in concealment, before launching a fast surprise attack.
  • With large paws and powerful hind legs, they’re sprinters that can run between 40 – 50 miles per hour.

Jumping Adaptation

Mountain lions can jump as high as seven queen-sized beds, stacked length-wise, end-to-end. This makes getting into trees easy and is an ambush asset.

Behavior

  • Traditionally thought to be solitary predators, biologists are currently studying complex family structures.
  • Mountain lions will reciprocally share kills within small communities controlled by dominant males.
  • Mountain lions can kill prey with a single bite to the neck, positioning teeth into the spinal cord between vertebrae.
  • These animals cache their meals. After a kill, they’ll bury the prey and continue visiting the carcass for up to a week. 
  • Males use feces and urine to scent-mark a territory, often scraping leaves and grass into a pile and urinating on it.
  • Young males searching for territory are more likely to fight and cause livestock problems.
  • Mountain lion relocation causes territory disruption, resulting in aggressive behaviors, and conflicts with established males.

Vocalizations are Mostly for Family

Humans may never know about lion neighbors, partly because we don’t recognize their vocalizations.

With other animals, scent marking is the main mode of mountain lion communication.  Within family units, mothers and kittens make a variety of noncat-like sounds.

Mothers make sounds to call for and locate kittens and kittens make distress calls that are answered by their mothers.

Purring may be sibling competition for food.

Caterwauling is used by females mostly in heat.

Diet

Mountain lions are obligate carnivores, they must eat meat to survive. Generally, they need to make one large kill (deer) every two weeks.  However, females raising kittens may need to make more frequent kills – every three days.

For an adult, average daily meat consumption is up to 10 lbs.

Food sources include;

  • deer
  • fox
  • skunk
  • rabbits
  • coyote
  • raccoons
  • river Otter
  • bobcat
  • squirrels
  • woodrats
  • rats and other rodents
  • any animal it can catch including livestock and housepets

In a Sonoma County study,

75% of mountain lion diet was deer,

10% livestock, 10% feral and house cats,

and 5% small mammals.

Reproduction

  • Females reach reproduction age between one-and-a-half and three years. Occasionally couples are monogamous, but more often mountain lions mate with multiple partners. During mating, a couple will remain together for about a week. After mating, the males go back to their own territory.
  • Gestation is approximately 3 months.
  • Females will have litters of 1-6 cubs, with an average of about 2. They’ll give birth every 2-3 years.
  • Cubs are born blind.
  • Nursing lasts up to 3 months.
  • Cub survival rate is slightly over kitten one per litter.
  • Kittens have spots for up to about 2 1/2 years.
  • Females raise their kittens alone.
  • Only mothers and offspring spend time together in social groups.
  • Juveniles remain with their mother from 1 1/2 – 2 years, until she’s ready for her next litter.
Photo credit: Eric Kilby

When kittens are nursed, the mother will bring meat to them. As they get older, she takes them to kill sites. Older still, they begin hunting small mammals on their own.

Photo credit: National Parks Service

Causes of Kitten Mortality

  • coyote
  • bear
  • hypothermia
  • wildfires
  • male mountain lions

Habitat Fragmentation A Breeding Problem

Southern California mountain lion studies reveal that male lions must have the ability to safely move between wide swaths of land to access and breed with diverse female populations.

With movement constricted by busy freeways, inbreeding occurs. This genetically weakens populations.

Mountain lion inbreeding tail deformities
Crooked tails are a genetic defect from inbreeding. Article: Genetic Connectivity Threatens a Southern California Puma Population by Ernst, Vickers, Morrison & Boyce

Experts believe if inbreeding continues, the Southern California mountain lions will go extinct within in the next 50 or 60 years.

Mountain lion inbreeding tail deformities
Ten genetic populations of California mountain lions (marked by color) Mountain Lion Foundation | mountainlion.org

Life Span

In the wild, the average mountain lion life span is between 8-13 years. In captivity, they’ve been known to live up to 21 years.

Predators & Threats

  • Genetic isolation & inbreeding (habitat fragmentation).
  • Rodenticides (rat and mouse poisons) traveling up through the food chain.  (In a study of 400 mountain lion necropsies, 95% showed some degree of poisoning.)
  • As habitats are encroached upon by humans, mountain lions are coming in contact with and susceptible to feline leukemia, rabies, and other infections.
  • Cars (roadkill).
  • Man and kill permits.

Nevada County Mountain Lion Kill Permits 2011-2019

Nevada County Mountain Lion Depredation Statistics 2011-2019 PDF

What Humans Can Do to Successfully Live in Lion Territory

Since we live in mountain lion territory, we should always assume we have an invisible mountain lion in our backyard and behave accordingly.

  • Don’t use anticoagulant rodenticides.
  • Value and support local and state policies aimed toward mountain lion conservation.
  • Never feed deer or other wild animals and encourage neighbors to do the same. (Wild animals who’ve lost natural fear of humans become a public safety issue, resulting in animal extermination.)
  • Fire safety – removing dense, low-lying vegetation close to your house – is identical for mountain lion safety.
  • Plant deer-resistant plants.
  • Consider outdoor automatic lighting.
  • Reduce driving speeds in wildlife zones, being especially from dawn to dusk.
  • Don’t litter and/or pick up roadside litter.
  • Don’t leave pet food outside.
  • Secure garbage on pick-up days.
  • Don’t let pets roam free.
  • Train guard dogs to watch-over livestock.
  • Build mountain lion resistant (very tall) livestock shelters.
  • Don’t put meat in compost piles.
  • Establish wildlife passage corridors to accommodate animal migration and movement.

Prevent Mountain Lion Encounters

  • Hike in groups.
  • Carry sticks.
  • Don’t bend down to tie shoes.
  • Make lots of noise.
  • Keep children walking in front of adults and within sight.
  • Carry pepper spray.
  • Keep dogs leashed. (A loose, running dog stimulates mountain lion chase behavior. If under pursuit, your pet will bring the chase straight to you!)

Attacks on Humans are Rare

Attacks on humans are very rare! The natural behavior for a mountain lion is to run away.

If a lion doesn’t run immediately;

  • Make sure it isn’t cornered.
  • Be big and loud.
  • Pull your jacket above your head.
  • Don’t crouch down or run.
  • Pick up children and back away.
  • Don’t make intense eye contact.

If it comes to a physical encounter, attempt to;

  • Fight back with rocks and sticks.
  • Stay on your feet.
  • Yell.
  • Protect your neck.
click image to purchase or see more Life on the Creek art
click image to download coloring sheet

 

If you like this article, you may also like Coyote the Ultimate Adaptor.

 

Resources:

Audubon Canyon Ranch – Living with Lions: ACR’s mountain lion research and education project
Bay Area Puma Project
BBC – What it’s like living in California’s mountain lion country [2017] – When a kill permit is issued
California Department of Fish and Wildlife – Commonly Asked Questions about Mountain Lions
California Department of Fish and Wildlife – Mountain Lion
California Department of Fish and Wildlife – Mountain Lion Depredation Statistics Summary
California Department of Fish and Wildlife – Verified Mountain Lion-Human Attack in California [ Two fatalities statewide in 34 years] California Mountain Lions – film & miniseries
CBS Denver – Dog Owner Says Lesson Learned After Encouonger with Moutain Lion [2016]

Conserving Connectivity: Some Lessons from Mountain Lions in Southern California, Morrison, Scott A. and Boyce
Conservation Society of California – Oakland Zoo – Mountain Lion Initiative The Cougar Conundrum: Sharing the World with a Successful Predator by Mark Elbroch | Revelator Article – What’s the Value of a Mountain Lion?
Los Angeles Times – After a nuisance mountain lion was killed, two L.A. city leaders wan to end the practice [2020] Los Angeles Times – Southern California mountain lions get temporary endangered status [2020] Mercury News – Mountain lions get endangered species protections in California
Mountain Lion Foundation
The Nature Conservancy – Animal Tracks 
National Geographic – Exploring the use of five type os puma vocalizations
NPR – The Secret, Social Lives of Mountain Lions | radio program 3:49
Sacramento Bee – California voters banned mountain lion hunting three decades ago, but the killing never stopped [2017] Smithsonian Magazine – California Will Build the Largest Wildlife Crossing in the World [2019] Liberty Canyon Wildlife Crossing PDF

Sonoma West – Living with mountain lions [2019] UC Davis Puma Project – New Study Details the Double Lives of Surburban Pumas [2004] UC Santa Cruz – Power of the pounce 
Wikipedia.org – Cougar

Predator Proofing for Livestock & Pets:

Preditor Proof Pens

Wildlife Rescue | Sonoma County | Puma Proof Pen

RSS
Follow by Email
LinkedIn
Share
Pinterest
fb-share-icon
Instagram