With Halloween right around the corner, I’m getting constant reminders of animals that give me the heebie-jeebies! Bats, spiders, snakes and all the other not-so-cute animals (I guess it’s all subjective) that have become symbols of the holiday are everywhere. And I know I’m not alone; it’s normal for everyone to have some fear of animals — the best parts of our evolutionary instincts doing their natural thing.

Despite those healthy fears, I know even the scariest animals play incredibly important roles in our ecosystems. Working for POST, an organization that’s helping protect land on the Peninsula and in the South Bay, I’ve learned a lot about our local wildlife and come to a deeper appreciation of the roles they play in our landscapes — even the super creepy ones. Preserving our region’s biodiversity has immeasurable benefits, including some we might not even know about yet, like the development of new medicines!

So, today I’m facing my fears. Below you’ll find seven local animals that tend to freak me out. It’s a distinguished list and I think it’s pretty obvious as to why these animals seem scary, I mean just look at ‘em! But moving past the fear, let’s instead consider why we so desperately need these critters in our world today.

I think you’ll be surprised:


A northern Pacific rattlesnake coiled, rattling and ready to strike.


I‘m both fascinated and terrified by these sly serpents. I’ve always thought it was so considerate that they rattle to warn us to back off. So thoughtful, right? I would say they’re arguably one of nature’s scariest but most considerate snakes.

The only species of rattlesnake found in the Bay Area is the northern Pacific rattlesnake. Generally considered less aggressive than their relatives, the timber and western diamondback rattlesnakes, northern Pacific rattlesnakes average about three feet in length. Most active from late spring into early fall, rattlesnakes prefer to remain under rocks, woodpiles and bushy areas. Their diet mostly consists of small lizards, rodents, amphibians and the occasional small bird.

Rattlesnakes are not known to be aggressive and do their best to avoid contact with people. In fact, our fear of these creatures ends up becoming a primary threat to their survival. People still feel justified in killing rattlesnakes because of the perceived threat. But as long as you follow these helpful tips, hiking in rattlesnake habitat is really no sweat!

Why they’re needed:

Snakes, in general, are excellent hunters. So, when it comes to controlling small rodent populations, they are the best of the best.

Rodents and other small mammals can have populations that explode in short periods of time. Rodents are also known to carry a whole host of diseases including Lyme disease and plague. Without snakes around to keep a level playing field, the effects would become very obvious, very fast! As for rattlesnakes in particular, their venom has been shown to be quite beneficial for humans in certain instances (please don’t try this remedy yourself!). Snake venom has been studied as a potential treatment for some types of cancer and even cystic fibrosis.



A big brown bat out of its element in the daylight, climbing to better camouflage and hiding. 


Bats get a bad rap as creepy bloodsuckers. And their appearance doesn’t help either (again, it’s all subjective — right?). But it’s almost like they’re trying to be totally strange looking with their small eyes and big ears — and don’t get me started on all that screeching!

I’ve come to learn that there are over 1,400 species of bats, but just 16 species call the Bay Area home. Some of the more common species you might see include the Mexican free-tailed bat, Eastern red bat, the big brown bat, Townsend’s big-eared bats and various mouse-eared bats — all of which are insectivores. (Only three species of bats feed on the blood of other animals and none of them live around here — phew!) Of course, bats are nocturnal, so spotting them in our local open spaces might be tough, though not impossible if you’re out around sunset.

Bats don’t only live in caves! They can also roost in trees, inside rock crevices and under bridges. The biggest threat that bats face is habitat loss and fragmentation as well as diseases like white-nose syndrome.

Why they’re needed:

If you eat fruits and veggies and dislike being bitten by mosquitos, bats are your buddies!

Bats can eat their own body weight in insects every day, which helps our local farmers. In fact, some farmers erect “bat houses” to encourage these flying mammals to stick around and feast on bugs. Other species of bats that feed on fruit and nectar are essential pollinators and seed dispersers. If you’ve ever had tequila, chances are the agave grown to produce the spirit was pollinated by a bat! Bats also make some quality fertilizers because of their guano.



With its web set, this black widow now awaits its next meal.


Creepy and crawly, spiders are probably at the top of my “critters I’d rather not see” list. But they are so good at what they do, it’s hard not to give them the appreciation they deserve.

There are over 45,000 known species of spiders found all over the world. It’s hard to say exactly how many of those species are found in the Bay Area, as they can be unknowingly transported from place to place due to their small size. The good news is that the vast majority of spiders are harmless and serve a critical role in our ecosystem.

Some species that can be found in the Bay Area that are especially gnarly include tarantulas, cross orb weavers, marbled cellar spiders (A.K.A daddy long legs) and western black widows. Spiders can inhabit a wide range of habitats, from bushes to caves and even underground. Because they are prey for many other species of animals, spiders often prefer to stay hidden and out of harm’s way.

Why they’re needed:

Their diet mostly consists of pest species like roaches, earwigs, flies, fleas and mosquitoes, which means they help prevent the spread of disease.

They also eat bugs like caterpillars, moths and earwigs that feast on crops. So, they’re a true friend to farmers (and in turn, all of us). Though they might not be very cute, spiders really are amazing creatures. They exhibit fascinating behavior and their silk is known to be an incredibly strong material. And just like snake venom, spider venom has been studied as a potential treatment for a range of disorders and diseases. Finally, spiders are a major source of food for thousands of species of animals including birds, reptiles, amphibians, fish and insects.



The elegance and power of the great white shark is inescapably palpable.


As a lifelong surfer, sharks are always at the back of my mind. I’ve spent too much time thinking about, researching and fretting about sharks. I guess it comes with the territory.

There are around 11 species of shark that can be found within the San Francisco Bay itself, and many more species that can be found on our stretch of the Pacific Ocean. The most commonly spotted shark in the Bay is the leopard shark, a bottom feeder with beautiful leopard-like spotting across its body.

Other species of sharks found near us include the spiny dogfish, Pacific angel shark, broadnose sevengill, salmon shark and, of course, the great white. Sharks have been around well before the time of the dinosaurs. They are well-adapted creatures that we continue to learn more about to this day. As an avid surfer, I’m here to assure you that the chances of being attacked are about the same as being struck by lightning! They have many more reasons to be scared of us than we are of them. Human activities like overfishing have pushed many shark populations to the brink.

Why they’re needed:

Because sharks are one of the apex predators of the sea, they play an intricate role in maintaining balance in the food web.

By reducing various prey species of fish and mollusks, they help ensure the overall health of the ocean. Just as terrestrial predators have an indirect effect on grassland and shrubs, sharks indirectly ensure kelp and seagrass ecosystems continue to thrive by preventing overgrazing. And bottom-feeding species of sharks are the clean-up crew of the sea, removing decomposing debris and, in turn, preventing the spread of disease.

The unique texture of shark skin has even inspired antibacterial surface technology, which could help reduce the spread of antibiotic-resistant bacteria in hospitals. Research is also being done on shark immunity genes in relation to cancer treatment as well as shark antibody research in hopes of treating Alzheimer’s disease.



Paper wasps are annoying even when not on my sandwich.


If not the scariest, wasps are certainly the most annoying. Can you please just let me enjoy my picnic in peace? Ugh.

There are hundreds of species of wasps in California alone. In the Bay Area, some of the most common wasps are yellow jackets, paper wasps, mud daubers, sand wasps, thread-waisted wasps and potter wasps. Wasps share many similarities to bees in that they both have two sets of wings, they both have social and solitary species, and in both, only the females can sting.

Unlike bees, however, wasps are carnivorous and hunt for other insects or spiders, though adults prefer to collect nectar and pollen from flowers. They are also able to sting multiple times, unlike the bee which perishes after one sting. Wasps are wise! Paper wasps are the first invertebrates known to be able to use the form of reasoning known as “transitive inference.”

Why they’re needed:

It’s clear that bees get all the love as being helpful pollinators, but wasps are pollinators too!

Adult wasps feed mostly on pollen and nectar and thus aid in the pollination game. In fact, fruits like figs rely exclusively on wasp pollination. And because wasps predate on insects to feed their young, they help eliminate pest species. Wasps are also scavengers, meaning they act like mini vultures, clearing out dead insects. Finally, wasps can carry yeast cells in their gut, which they then pass on to fruits like grapes. So next time you’re having a glass of wine, raise one up!



The king and queens of the Santa Cruz Mountains, we need mountain lions in this landscape.

Mountain Lions

Any fear of large cats is entirely rational, but that doesn’t diminish their stunning beauty and grace. And with a few precautions, there’s really no reason to worry.

Mountain lions (aka pumas, cougars or panthers) are the majestic kings and queens of our local forests. Their coats can range from a tawny yellow to a darker brown, with patches of white around their belly and snout. Adult males can be as long as eight feet from nose to tail. The truth is that they’re shy, reclusive animals, rarely spotted in the wild as they try to avoid humans whenever possible.

These solitary big cats feed mostly on deer and other small mammals. Because they have, at times, gone after livestock and small pets, their conservation story and reputation is a complicated one. One of the biggest threats to the survival of pumas in the Bay Area is habitat destruction because they need such large areas of open space to safely move around and find what they need for survival. Another major threat to their survival is direct mortality from vehicle collisions and depredation due to run-ins with livestock.

Why they’re needed:

Mountain lions are a critical part of our ecosystem — the apex predator with the top spot on the food chain.

By predating on deer and other small animals, they maintain balance in the ecosystem. By controlling deer populations, for example, they help to minimize overgrazing and slow the spread of disease. They also boost biodiversity by leaving behind remnants of their kills, inadvertently bringing vital nutrients to the soil and feeding a whole host of scavengers and decomposers like eagles, foxes, beetles and more.

Learn more about how you can support local mountain lion conservation here: Bay Area Puma Project



Turkey vultures are as graceful as they are ugly.


Vultures win: flying, bald-headed, carrion-eating, black-winged creatures that can spew dangerously potent stomach acid as projectile vomit. Yea, that sounds pretty terrifying.

The new world vulture or condor family is made up of seven species of birds. Of those seven, there are three species that can be found within the United States: the turkey vulture, the black vulture and the California condor. Of those three, the turkey vulture and the California condor are the species that hang around the Bay Area. The California condor, as many already know, nearly went extinct in the 1980s when the number dropped to less than two dozen. Fortunately, these birds (which are among the largest in the U.S) have been making an epic comeback.

Vultures are the infamous scavengers of the bird world. Because of this, they have long been associated with death and cast as the villain in some of our favorite cartoons. But the truth is, these birds are survivors and have some truly unique adaptations. They are resistant to most pathogens, they have incredibly acidic stomachs to help break down their scavenged meals and they will even use their acidic stomach contents to vomit on — or towards — other animals that pose a threat (yes, really!).

Why they’re needed:

The landscape’s proverbial garbage collectors, these birds keep us all safe.

Though they might not be the prettiest bird around, turkey vultures play a necessary and unique role in our ecosystem. They are the clean-up crew from above, using their incredible sense of smell to track down fresh animal carcasses and pick them clean. And because they are resistant to most pathogens, they prevent diseases from spreading.

Carrion (decaying flesh) also attracts insects and bacteria, so when vultures are around to clean it up, they indirectly reduce the prevalence of these bugs. Though there are plenty of other scavenger species around, vultures are unique in that they are less likely to spread disease to humans and other animals. Last but not least, after vultures are done with their meal, they are kind enough to return the digested nutrients to the soil via their poop, completing the cycle of life.

About Post

Peninsula Open Space Trust (POST) protects open space on the Peninsula and in the South Bay for the benefit of all. Since its founding in 1977, POST has been responsible for saving more than 87,000 acres as permanently protected land in San Mateo, Santa Clara and Santa Cruz counties. Learn more

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