Other Critters. Amphibians

Transcription

1 Other Critters Foothill Yellow-legged Frog, courtesy of Dr. Kerry Krieger Big Brown Bat Christine Volker SAVE THE FROGS! Life in the suburbs, and even in cities these days, is not without wild critters. As land became developed, many were driven to the margins, others entirely wiped-out, but still others have been cunning enough to forge an existence next to us. They re our wild neighbors. Each performs a function in the ecosystem we also inhabit. Living among us, the successful ones try to survive by staying out of our way. It ll help all critters (including human pedestrians) if we slow down and pay attention to the road when driving. Taking pets in at night, (along with their food) will also diminish clashes and casualties. We ve mentioned in other posts the importance of no pesticides, herbicides and rodenticides (which cause bleeding in predators eating rodents) and repeat it here. Let s review highlights of key families, with some of the most endangered, first, and discuss what we can do to foster those most threatened. Amphibians There are 7,000 amphibian species in the world; 90% of them are frogs. Others are toads, salamanders, newts and a group resembling worms, called caecilians. Amphibians are cold-blooded and are dependent on the conditions of their habitat. Most amphibians have two life stages, larvae undergo an amazing metamorphosis into the adult stage. In the case of tadpoles with gills, which resemble fish, the heart even changes as the animal becomes a primarily air-breathing frog with lungs. Frogs can breathe through their skin and can do so underwater. Tadpoles eat pond algae, helping to keep ponds clean and supporting life of other water dwelling animals. Adult frogs and toads are predators and eat insects, or anything else that can be crammed into their mouths. Toads are adapted to drier land and there are two dozen toad species in the U.S. However, they, as well as frogs need water for egg laying and reproduction. Frog song, during mating season, can be quite beautiful. By singing, the male risks being found out by a predator, but he can t help himself. The

2 Pacific Chorus Frog (also called Pacific Treefrog) is a resident of Point Richmond and has been heard in prior winters, but not this one, at least by this writer. While frogs and toads are vocal, you may not notice quiet salamanders on your property unless you are turning over rocks, logs and leaves. They feed on insects, snails and worms. The bad news is that more species of amphibians are going extinct, faster, than any others on earth. 122 species have gone extinct since 1980; one was the first casualty of climate change. Fully 3,000 species of amphibians are threatened, with 500 needing immediate intervention to avoid extinction. Their sensitive and moist skin easily absorbs pesticides, herbicides, fertilizer, pollutants and other chemicals, including endocrine disruptors. In addition, a killer, chytrid fungus, which started overseas, has taken root in amphibians here. Add to that, habitat destruction, introduced invasive species like the Eastern bullfrog, or African bullfrog which outcompete and predate, climate change with hotter and drier conditions, along with frogs killed for food/dissection by humans and you get the picture. How can you foster a healthy amphibian population? Eliminate pesticide/herbicide use, grow native plants of various heights to offer protection, keep some leaf and brush piles. Consider a small pond in a shady part of your property. More information and videos about frogs can be found at: If you d like to hear a frog song, visit: Bats Bats are fascinating creatures with an undeservedly bad reputation. News flash: there are no vampire bats in the U.S. on Halloween or otherwise. Bats generate wonderment by their flying and echolocation abilities to find prey. Some bats even sing. They also benefit the planet and humans in many ways species of these flying mammals provide insect-eating, pollination and seed dispersal services. They pollinate 530 plants around the world, like bananas, mangos, and via the bats search for nectar and pollen, they are the sole pollinators for the agave plant: say goodbye to a margarita without them. Estimates are that bats render up to $50 billion in agricultural and human health savings per year on a global basis. They munch on insects, like mosquitoes, and agricultural pests, in an environmentally friendly, pesticide-free way. Most bats would not win a beauty contest, with the exception of some fruit-eating bats and flying fox bats, but who cares since they can eat their body weight of harmful insects every night. A large group of bats can literally eat a ton of insects, plus Mexican free tailed bats accomplish this at altitudes up to 10,000 feet. An added bat benefit is their guano fertilizer and as they disperse seeds, they are spreading forests, particularly the rainforest. Some bats can live into their 30s and 40s. Females give birth to just one pup per year. But six million bats have perished in the past decade, in North America. A major cause is a fungus ( white nosed syndrome). Their population decrease is also due to the ongoing loss or disturbance of habitat (including shrinking forests). Wind energy is responsible for around 900,000+ deaths annually via turbine blades themselves, or the rapidly changing pressure causing bat lungs to burst.

3 Bats have been spotted in Richmond. Consider a bat house if you have a lot of land, but read up first. And don t forget to take our separate bat quiz it s fun! More information about bats can be found at: and norcalbats.org. Hear bats singing at: Opossums Around the size of large house cats, opossums are North America s only marsupials. These solitary and nomadic omnivores were alive seventy million years ago, along with dinosaurs. Up to thirteen young can attach in the mother s pouch, where they spend two to three months. Afterwards they ride on her back for another three months before striking out on their own. Opossums are generally nocturnal, but a female may be out in the daytime foraging for food for her young. Their wide-ranging diet consists of: cockroaches, spiders, crickets, beetles, snails, rats, mice and carrion. These animals can famously play possum, but that s actually an involuntary reaction, like fainting, to a very stressful situation and can last from forty minutes to four hours. Overall, opossums are gentle and slow moving, using their tail as another limb to help in climbing or nest building. Opossums live just one to two years in the wild due to many predators. Very few even survive to adulthood. Dogs, cats, people (and their cars), attack them and owls prey on the young. We have a lot to learn from nature and opossums deserve their space in it. They have partial or total immunity to snake venom and are more resistant to rabies than any other mammal. For more information on these critters, check out Gray Fox A number of you have seen at least one gray fox roaming around the Point, or lounging in a hammock at night (true story). At eight to fifteen pounds they re small, nocturnal animals. Interestingly they re in the same canidae family as dogs. Gray foxes live in hollow trees, stumps and burrows. With their hooked claws, they can actually climb trees to escape predators and sometimes sleep up there as well. One to seven kits are born in the spring/early summer and the little guys learn how to hunt at three months. Generally they live six to eight years. Gray fox are carnivores, but also like fruit. Their main diet consists of: rodents, rabbits, squirrels, fruit and birds. They prefer forested or brushy environments and areas close to water. Predators include coyotes and great horned owls take kits.

4 Check out the work done by two citizen scientists focusing on the gray fox of Silicon Valley. They re also pushing for wildlife corridors in the Bay Area. Information and a short film on the foxes, including their barks, are found at: Skunks There are four species of skunk in the U.S. Weighing up to thirteen pounds, they mate in early spring with a 66 day gestation period. Babies, generally five to eight, are generally born in May and stay with their mother until one year of age. Skunks are shy and do not venture more than two miles from their dens made in tree hollows, brush piles, or underneath porches. They begin foraging around sunset. Their diet consists of: beetles, wasps, worms, grasshoppers, other insects, fruits, berries, mushrooms, frogs, small rodents and eggs (70% of their diet is comprised by insects harmful to humans). They re immune to snake venom. While skunks have poor eyesight, they do have excellent hearing and smell. Skunks can run at a top speed of ten mph. No wonder they need some protection, courtesy of their malodorous spray. When threatened they don t want to spray unless they feel cornered and cannot make a run for it. They have a limited supply of spray at any one time. Generally they give warning: first comes foot stomping, then hissing, with the last resort being spraying with good accuracy up to ten feet. Move away slowly and shield your eyes. Skunks are immune to snake venom. They can live five to eight years but generally just two to four years in the wild. Owls, coyotes, and wild cats are predators. So are humans and their cars. Resources to resolve skunk problems: php#item Deer Deer have some surprising qualities. They can see 310 degrees given their eye placement. They can detect human odor at the half-mile mark and water, two feet below the ground. Their sense of smell is around 1,000 times stronger than that of humans. With one bound they can jump up by two feet and travel fifteen. These ruminants weigh from 130 to 280 pounds, browsing on shrubs and grasses. Many deer spend their lives in a five mile radius of a local park, foothills, backyards or golf courses. Born in the spring after a 200 day gestation, fawns remain with their mothers over the summer and are weaned in the fall. They can live from 9 to 11 years in the wild.

5 The Department of Fish and Wildlife estimates there are now 445,000 deer in California, down from two million in the 1960s and 850,000 in the 1990s. This is generally due to habitat loss and diminished habitat quality. For 30 years, California's population growth has converted about 75,000 acres of wildlife habitat per year to housing, which a loss of 2.25 million acres of places where wildlife can no longer live. In many national forests, diverse ecosystems were cut down and replanted with conifer monocultures. With few hardwoods and less material to browse in second-growth forests, food for wildlife has been reduced. With that, overall nutrition for deer can be poor, which can bring reduced survival rates. More than 25,000 deer a year are killed by cars in California. On the positive side, fawns have been reported this year in Point Richmond. Raccoons They d prefer a forest and a stream, but here they are, stuck in suburbia, with no way out. They re highly intelligent and adaptable omnivores, eating snakes, insects like grubs and grasshoppers, bird eggs, mice, gophers, fruit from your garden, you name it. Ranging from usually 10 to 30 pounds, they fit nicely through doggie doors. Raccoons stay close to their den, generally not ranging more than a mile from it; they also change residence frequently. Raccoons communicate with 200 different sounds and different calls. Their sense of touch is unique and extremely important for them. Oddly, their forepaws even have whiskers to further determine what they are touching. Raccoons are great climbers and can rotate their hind feet in order to climb down a tree head first. With their paws and heft they can tip over garbage cans and rummage for goodies. Any chickens need to be well enclosed and protected from raccoons, who can tunnel. Raccoons little paws can open doors and bottles. Each year an adult female can produce from one to six kits, which generally leave in the fall. Just half of the litter survive to the next year. Large owls and eagles will prey on little ones. These animals can live up to twenty years in captivity, yet just two to three years in the wild. More than anything, adults are killed by cars. Dogs also kill them (or vice versa). Apart from humans and pets, other predators are coyotes. Do not get close to a raccoon their claws can be a deadly weapon and their teeth are also strong.