California is home to many species; unfortunately the grizzly bear is no longer one of them - despite its prominent place in the state flag.
That said, the smaller black bear and brown bear can still be found in the mountains where you are advised to heed the warnings. Your car will not look to your liking if a bear has tried to get to the granola bars. Just a packet of chewing gum or a tube of toothpaste may cost you a trip to the garage. Bear proof waste bins are the norm outside of the cities, and although some bears hibernate, you may still accost one waddling down a side street in the ski areas once the sun is down.
But even in "surburbia" you will find nocturnal activity. The raccoons often spend their days in the storm drains. At dusk you can meet whole families crawling up into the gutter and they are expert crawlers so you can't fence them out. They are very adept at opening normal trash bins, hence they thrive in proximity to humans.
The local newspapers pay much attention when a mountain lion is seen in the more populated areas. Also known as the puma or cougar, the mountain lion is big enough to kill a deer - or you. They will rather avoid people, but if your are trekking off the beaten path, make sure that you know how to make yourself look big and keep your kids within line of vision. The idea of moving quietly through nature in the hope of spotting wildlife includes the risk that wildlife either spots you first or gets surprised and defensive. If you make noise it will move out of your way. So observe that the trails close at dusk, not to annoy you but to have fewer people around when the mountain lions hunt.
The bobcat (the lynx) is a smaller cousin known by its "bobbed" tail and pointy ears. It is not common - but way more common than the mountain lion. While I have never met the latter, I have seen bobcat several times - including the one lounging in my back yard at occasions.
You may also come across the coyote in the foothills. This pack animal is bigger than a fox but smaller than a German shepherd and is not really dangerous to humans. If you live within its territory it may chase your cat or dog. In the populated areas you normally just see them single or as a couple - in the wilderness bigger packs may be more aggressive.
Even less welcome, meet the skunk. If you only have seen one in Disney's Bambi, you can't possibly imagine the odor of this small black and white animal. Its very well developed anal glands can move independently and be amazingly accurate at aiming at any perceived enemy. It smells just as bad - even if the stench is not quite as pervasive - if it just passes by your open window. Once our sprinklers startled a visiting skunk... yikes, the windows were tightly closed for the rest of the night.
If your poor dog has been sprayed, you can neutralize the smell somewhat by washing it in tomato juice. A viable alternative is to call for a mobile dog trimmer as you really don't want your dog inside or in your car until it has been taken care of.
So if you are out driving and your car suddenly fills up with this fatty, rancid stench it is probably a skunk that mistakenly believed that a car - like most other predators - can be scared away by its lifted tail. It doesn't have many other enemies (although one species of owls have adapted by not being able to smell anything. Evolution at its best!)
Moving down in size, the next dangerous animal is the rattle snake. In the morning you can meet it coiled up in the sun in the middle of a trail, trying to get the cold of the night out of its body. Later in the day the snakes often seek the shadow of a hollow tree or a ground squirrel hole, so don't put your hands where you can't see them and don't let your kids play in hollow trees without checking for snakes first.
The smallest snakes are the most dangerous. Older snakes know to hold back some venom in case of more than one enemy around - the younger give all they have. Fortunately, they rather want you to back away and will use the rattle to scare you off. I almost stepped on such a little snake, thinking the sound was from some flying insect. I was 30 cm away but it didn't strike at me. So if you see a snake just give it some space. I have done that the other 4-5 times I have met one - and for my own peace of mind made it at a distance of more than 30 cm.
Supposedly it is very painful to get bitten and the best you can do is to be still, whip out your phone, and call 911. If you are out of coverage or don't have a cell phone, get somebody to run like crazy for help and don't try to be a hero. The hospital has helicopters for rescuing people from the hills.
You may also encounter a tarantula, a big hairy spider, with a leg-span of 10-15 cm. Some people keep these spiders as pets so they are not overly aggressive. Although poisonous and unpleasant if they bite they are not deadly.
The much smaller Black Widow spider is way more dangerous. It lives in dark, moist places like wood piles and garages - and I think one lives at the entry to the crawl space under my house. These spiders are the kind that gives the whole Arachnid family a bad reputation. Shake your wellies and use gloves when moving firewood around. Black Widows have a red hourglass spot on the belly - get to know what they look like and call the exterminator if you meet one - it may have a family.
If you have kids, teach them when they explore under rocks and branches to turn these away from themselves. It may not be all centipedes and earth worms under a rock, and it will be much better if this something runs away than up your legs.
Among the smallest pests are ticks that can cause Lyme disease and mosquitoes that may carry West Nile or Zika virus. Vector control look out for green swimming pools from the air, but just water in a wheel barrel or inside an unused tire swing may be good breeding grounds.
Enough of the scary stuff!
Enjoy the big flocks of white or brown pelicans on the bay. The turkey vultures are impressive in the air - and darn ugly close up. Hawks, kites, falcons, and harriers, jack rabbits with their long ears, and ground squirrels galore. If you are really lucky, you may see a burrowing owl.
In the hills there are deer, flocks of wild turkey, bullfrogs, and turtles in the ponds. You may meet the horned lizards or the California Quail, the state bird, whose offspring run around like ping-pong balls with legs in the spring.
In Santa Cruz you can find one of the winter habitats for the Monarch butterflies. An Natural Bridges State Beach, there is a valley where Monarchs hang from the branches in the thousands like dead leaves, and when the spring migration sends them off towards Canada, there are butterflies all over.
You may meet an opossum, the only marsupial on the continent. It is not cute. My association is to Rodents of Extraordinary Size from the movie The Princess Bride. No, not quite as big, but four times the size of a rat with pink ears, snout, and tail - and dirty white fur.
Our back yard entertainment constantly contains squirrels. We have oak trees and the squirrels love acorn. The gray squirrels seem to disappear against the tree bark. Squirrels that mainly live on pine cones are redder in the fur better to blend with the redwoods. They also love pumpkins so my post-Halloween treat is to give them a big uncarved pumpkin. It is not uncarved for very long, the squirrels love the rind, and once they figure out that there are 500+ seeds in the middle, they have a ball. We have had the fattest squirrels of all, and as their fur takes color after their "favorite habitat", the most gluttonous take on a shade of orange.
The only animals you really can feed are the birds in your yard. Squirrels will also try to eat your bird feed so you have to chose the right kind of feeder and place it with care. But only the hummingbirds (and perhaps the ants) can get to a hummingbird feeder, a upside down bottle of sugary water with perches for the birds. The water must be changed at least once a week and the feeder washed thoroughly less there may grow mold on the inside that can kill the birds. The hummingbirds are very aggressive and protect their territory with a vengeance. So only one family will be able to enjoy your feeder - the "owner" will come whistling like a Spitfire from the treetop if others try to steal its food.
At the ocean, you can encounter both danger and peace. You will neither enjoy stepping on a sting ray, nor a meeting with the Great White shark - who breeds by the Farallon Islands just west of San Francisco. The risk of ray is greater than of meeting a shark, and mostly if you spend time on the southern coast where the water is warmer than 5C. That said, the ocean is in itself a risk: the water is cold, the currents can be strong, the surf if powerful, and even the North Sea is just a small bay compared to the Pacific Ocean.
It is more charming to encounter hump back whales. Their breeding grounds are in the Sea of Cortez, just across the border to Mexico, but otherwise they feed up by Alaska. Consequently, big herds of hump backs migrate up and down along the coast together with blue and gray whales. You don't often see them from the shore but there are fleets of whale watching boats in many coastal towns. It is not for the faint hearted - and certainly not if you easily get sea sick. And don't expect the whales to jump out of the water like you see on TV. They are usually too busy migrating to put on a show; you will more likely see a tail, a flipper, or the spray at a distance. Seymour Marine Discovery Center in Santa Cruz has a blue whale skeleton exhibited outside, and you can learn a lot more about whales there. The center is part of the Institute for Marine Biology at the University of California Santa Cruz (UCSC),
An alternative is a trip to the Monterey Bay Aquarium. At Monterey, the sea floor drops to 3000 m right off the coast and consequently there are currents, food, and plenty of life right below the surface. And on the surface as well. You can see sea otters in the bay - without having to visit the aquarium. It is well worth the drive.
North of Santa Cruz lies Ano Nuevo State Park. This is one of the few breeding grounds for the sea elephants. From December to April you can experience first the dueling bulls, fighting for their piece of territory, followed by the pregnant cows who will nurture their newborns on the beach. During the calving season, you can only visit the park with a guide. But you will get surprisingly close to the animals. Don't let the kids run lose - the big gray rocks in the dunes are not what they appear; they are five tons of blubber that can move surprisingly fast if you annoy them. 28 days after giving birth, the mothers set off to sea again, leaving the young ones on the beach almost 200 kgs heavier than when they were born. The mothers - on the other hand - have not eaten during those 28 days; between starving and feeding their calves milk with twice the fat content of creme fraiche they have lost between a third and half their body weight. Thus trimmed and slender they are too much of a temptation for the bulls guarding the beach, and the poor cow will be pregnant again before she reaches the surf. If she survives the encounter with the up to five times as heavy male and has the wherewithal to dodge the killer whales and sharks patrolling the waters, she will set the course for Hawaii to eat squid. Somehow I can't blame her for wanting a trip to Hawaii.
As if the animals couldn't give enough excitement, you also have to watch out for the plants. One of the most ubiquitous is a vine called Poison Oak. The leaves bear a resemblance to oak leaves and the poison is an oil covering leaves and vines that most people are allergic to. Even during the winter, when the plant has lost its leaves, the stems can still infect you.
It is a great pity that it is such a rogue as the plant itself is very beautiful. The shiny dark green leaves would look great in a bouquet, and in the fall - when the leaves change into flaming reds, yellows, and oranges - you could make a fantastic wreath. Don't. Not even for you mother in law. You will have plenty of time to wash your hands - I find that dish washing liquid works well, you can use chlorine, or you can get special Tecnu soap at the pharmacy. But you must also wash what else you have been in touch with, clothes, the car seat and steering wheel, the dog...
The problem arises when you are not aware that you have gotten the oil on you. Perhaps the dog had it on the fur; perhaps you brushed against a vine not knowing that it was poison oak. Then you have scratched your ear or touched your face. After a day or so the skin starts itching; you get little blisters, and if you scratch back and get the oil into the blood stream you may need a trip to the ER with shock. Antihistamine helps, you may need steroids later. Nasty business, be smart about it.
Live Oak, a local evergreen, and eucalyptus trees can both shed limbs without much warning. The eucalyptus drops branches to reduce its surface area if there is drought; the oaks may suffer from gravity in general; if they are not pruned the branches get very heavy. As the weather usually delivers plenty of moisture during winter and plenty of sun the rest of the year plants grow very fast. Fortunately, falling branches and people are rarely at the exact same spot at the exact same time, but people do get hurt. Tree trimming is a big industry that you will support if you have trees.
The California Poppy, the orange state flower, is on the other hand quite peaceful. It designates picturesque routes like the winding Highway 1, the coastal highway, or Interstate 280 down the middle of the San Francisco Peninsula.
The State tree, California Redwood, Sequoia Sempervirens, are the tallest trees in the world. They are also quite peaceful and very useful as timber. You can't, however, just take down a Redwood as they are a protected species. Cut down a grove in your back yard without permission and you will be heavily fined.
Redwoods only grow where there is not too much rain and where the climate is not too hot. The narrow canyons in the Coastal Ridge mountains give them the protection - and incentive - to grow very tall and in Muir Woods north of San Francisco some have grown to almost 100 meters.
The Giant Sequoia, the thickest trees on the planet, are as famous as the Redwood. You can find them in Yosemite National Park and - not surprisingly – in Giant Sequoia State Park. Some of the trees are so old that they house their own private ecosystems. The trunks may grow hollow with age and species of mosses, fungi, and lichen may have developed and mutated undisturbed along their own path down in these thousands year old "caverns".
Nature is one of America's most precious resources but it can easily be underestimated if you come from the more densely developed Europe. Every year 10-20 people lose their lives in Yosemite National Park alone, while rappelling or just not respecting the signs and fences. So remember to tell somebody if you go trekking, bring water, and respect nature - it can be unforgiving if you don't.