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
Even though it has ‘tree’ in its name, the Sierran Tree Frog is mostly found near the ground.
Habitat
Tree frogs live in bushes and grass. Their preference is for damp, moist areas.
Behavior
Large toe pads that allow it to walk on vertical surfaces. The toe pads are also useful for clinging to sticks and twigs.
To avoid being eaten, the Sierran Tree Frog is fast! It can jump long distances and swim quickly to hide. It also remains perfectly still and changes color to stay camouflaged. Sierran Tree Frogs can change from green and gray to brown.
The Sierran Tree Frog is more often heard than it is seen. Males call to advertise availability and attract mates. Breeding and egg-laying occur from November through July. During this time, males establish a territory that they defend with encounter calls, butting, or wrestling with rivals.
Diet
Worms, small invertebrates, and flying insects are the frog’s dietary staples.
Tadpoles feed on algae, bacteria and organic debris. Their feeding activities help keep streams and waterways clear of slippery plant material.
Global Amphibian Issues
Scientists say that we are living in the Anthropocene epoch, a time when human activity is the dominant influence on climate and the environment. Unfortunately, the consequences of this are that many habitats and species will disappear.
Frogs and newts are indicator species because they have thin skin that easily absorbs pollutants. Since they live both in water and on land, they absorb toxins from both environments. Like the miners who used canaries to warn when toxic gas was present, amphibian health determines the quality of the environment.
There are a number of factors that affect amphibian populations. Not unique to Nevada County, these conditions are happening globally.
Factors Contributing to Amphibian Decline
Housing and Habitat Loss
“We’re running out of places where frogs are healthy,” Amphibian Study Volunteer
“It doesn’t matter how many frogs we save if there is no place to put them back in the wild,” Edgardo Griffith, El Valle Amphibian Conservation Center
Chytridiomycosis (Batrachochytrim dendrobatidis) Skin Fungus – A Global Epidemic
The state produces half of the US agricultural produce.
99 percent of artichokes
99 percent of walnuts
97 percent of kiwis
95 percent of garlic
89 percent of cauliflower
85% of the lettuce
71 percent of spinach, and
69 percent of carrots
Contaminated agricultural water runoff affects the entire ecosystem.
“Atrazine (an herbicide) is the most common contaminant in our drinking water. It causes male frogs to turn into females.” – Tyrone Hayes, UC Berkeley Biologist
Invasive Bullfrogs
“Bullfrogs pose several threats to the native amphibians of California, many of which are endangered. When bullfrogs—the largest frogs in North America—escape or are released into the wild, they have a tendency to eat other amphibians and any other wildlife that will fit in their mouths. Their size also allows them to outcompete native species for food. Even worse, a large portion of the bullfrogs imported into this country—62 percent according to one study—are infected with the deadly chytrid fungus (Batrachochytrium dendrobatidis), a lethal skin disease which has already been blamed for extinctions of about 100 amphibian species around the globe.” – Should California Ban American Bullfrogs? Scientific American Blog
How to Help
Speak up for Nevada County frogs, toads, and salamanders.
If you see a frog die-off (more than one dead in a single location) – DON’T TOUCH IT – but do report it
Don’t move amphibians from one location to another
If fishing, wash & dry gear before moving between spots
Don’t pour anything down a storm drain that would damage amphibians
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.
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.
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.
