WildCare -- February 2011 eNewsletter
table of contents
|
|||||||||||||||||||||||||||||||||||||
wildlife corridorsIt’s mating season, better known as Valentine’s Day to us. You’d like to get out and meet someone new, but you don’t have a way to get out of the little town where you grew up. All the members of the opposite sex are too old, too young or one of your relatives. What’s a wild animal to do? habitat fragmentation You can visualize habitat fragmentation by thinking of islands separated from each other by expanses of water. On islands, some species are cut off completely from the larger mainland population and, in time, can become their own distinct species. Examples of this phenomenon are California’s Channel Island Foxes, descendents of the mainland Gray Fox, and Florida’s Key Deer, a sub-species of the White-tailed Deer. Both of these species are significantly smaller in stature than their ancestors, and have other differences that distinguish them as their own species. As human populations grow, we're creating "islands" of habitat for many wild animals, non-contiguous areas separated, not by water, but by human obstacles. This is called habitat fragmentation, and it is causing the isolation of wild animal populations to accelerate, and sometimes threatens the extinction of entire species. Impassable obstacles for wildlife take many forms. For instance, Belvedere in Marin County was once an island separated from the mainland by a marsh and sandbars, accessible only at low tide. The island has now been linked by two roads, but island-locked species like deer and raccoons are reluctant to use the roads. These roads are corridors for us, but don’t provide enough protection to allow wildlife to feel comfortable traveling freely between different areas. WildCare's Wildlife Hospital often sees young, healthy animals that have been hit by cars. These are often the result of these animals' attempts to cross between habitat fragments, through areas that provide neither food nor shelter, as they search for more hospitable areas and possibly a suitable mate. Habitat fragmentation doesn’t only involve water or roads, though. It is frequently caused by humans when native vegetation is cleared for agriculture and other development. Habitats that were once contiguous become divided into separate fragments. After intensive clearing, the separate fragments tend to become very small islands isolated from each other by cropland, pasture, pavement, or even barren land. Even birds are subject to habitat fragmentation, when the suitable environment in which they have evolved is changed by development. Some species, such as Western Bluebirds, have evolved to exploit highly specific habitat types, and when those features (hollow trees in this case) are removed, the species simply doesn’t breed and is headed toward a dead end. Human intervention (in the case of bluebirds, the installation of nest boxes) can help mitigate some of the difficulties these animals face, but our activities are creating a world where the only species that will thrive are commensal, that is, those that can quickly adapt to life among humans. Crows, raccoons and coyotes are a few species that are finding success in human habitats. Interestingly, these are often the species we seem to value the least. wildlife corridors Wildlife corridors have been proposed as a means to moderate some of the adverse ecological effects of habitat fragmentation that threaten many species unable to take advantage of human development. Conservation planning is the science of determining which habitat areas must be protected to ensure the survival of these species, and to maintain biodiversity and functional ecosystems. Setting conservation priorities requires detailed information on the distribution of species and habitats throughout the landscape. A team of California Department of Fish and Game scientists has developed a new interactive mapping tool for use by scientists, conservation planners and the public. The Biogeographic Information and Observation System will allow users to view information on biological diversity throughout California. The map can also display other data needed for conservation planning, such as the location of State Parks, Game Refuges, lakes, watersheds, highways and cities. For the rest of us, it can help us visualize issues that are of importance to local decision making, such as the recent legislation about the Tiger Salamander in Sonoma County. corridor evaluation The Center for Biological Diversity outlined a six-step “checklist” for evaluating corridors in their document titled Principles of Wildlife Corridor Design. This evaluation includes considerations of how likely the animal will encounter, enter and follow the corridor to the end; whether there is sufficient concealing cover, food and water within the corridor; and whether there are impediments to movement such as roads, fences, outdoor lighting and domestic pets. Wildlife corridors are not a solution to habitat loss, but, with careful planning and design, they can help reduce the negative effects of habitat fragmentation by allowing the dispersal of individuals between large patches of remaining habitat.
|
|||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||
urban coyotes have livesCoyotes are moving into urban areas. They are bridging the seeming contradiction between urban and wild — and in so doing, they are creating a much more balanced ecosystem for us all. What a thrill if you encounter one! Coyotes tend to be shy of humans, so a glimpse now and then is all most of us can expect. I’m lucky enough to have been allowed by some coyotes to watch them — aided by a mutual respect that developed slowly over time. I want to share some of my observations, to let everyone know about some of their many different behaviors — behaviors which most of us don’t see — and to show how similar in many ways they are to us. We are all critters on this earth with very similar feelings and needs going on — this is the connection. meet the new kids on the block They also exhibit some “softer” characteristics such as affection, care, happiness, patience, timidity, dejection. Included in this article are some photos showing fun things about coyotes to help everyone get in touch again and feel connected to the wilderness in our midst and our own human natures. follow the rules A little precaution is all you need to coexist with coyotes. One thing we see in nature is that other animals’ rules are often different from our own. Learning about animals' behavior and their rules, and then balancing these with our own might be the first step towards sharing the environment. A little bit of effort and understanding on our part can engender a lot more fun and a feeling of connection when we finally do encounter wildlife. Maybe we can learn to fit in again rather than to dominate with our own needs and expectations. It is relevant to know that coyotes are living their own lives and are not too concerned with people. They will do their utmost to avoid humans. So an encounter along a path is going to be simply a chance occurrence — the coyote may look at you out of curiosity before it flees. If you want it to move faster, make a racket to shoo it off. The few instances of coyote aggression toward humans are known to be caused almost exclusively by humans feeding them or taming them through feeding. What is freely given eventually becomes aggressively demanded: never feed a coyote! But also don’t approach them — give them the space they need to feel safe. If one comes too close, again, shoo it off with a racket of noise. Tossing pebbles in their direction — not at them — is also an effective deterrent. If you have a jacket or sweater, flapping it at them can also be a deterrent. coyotes and dogs Dogs pose a totally different set of circumstances for coyotes than do humans. Coyotes see dogs as intruders who might want to claim their turf. Coyotes are territorial, so they have a prerogative and a vested interest in the territories that provide them with the food and shelter they need to survive. Keeping our dogs restrained on a short leash, and “moving on” is the best policy in coyote territory. We can coexist by giving in just a little in this manner. reputation vs. reality Although they can be fierce fighters, coyotes are, generally speaking, far less dangerous than dogs. For perspective, in any given year there are only about 27 coyote bites in the entire United States. The bites rarely cause severe injury because of the coyote’s small size. In comparison, more than 1,000 dog bites send people to hospital emergency rooms daily. Coyote reputations should be brought in line with reality. This being said, keeping one’s distance gives both coyotes and humans a feeling of safety, and small children must always be kept away from wild animals. If a coyote/dog incident does occur, distract the coyote by making a loud racket, grab your dog, leash it, and move on so as to minimize visual and body-language communication between the two animals. Coyote pupping season, which begins in March, is when such incidents are more likely to occur, though they have occurred at other times. Pet food and garbage left out in the open and within easy reach serve as an open invitation to animals looking for food — remove the invitation to discourage uninvited guests. And, all pets, but especially small ones, need to be kept indoors as a safety precaution. Janet Kessler is a naturalist who has been observing and photographing urban coyote behavior and urban coexistence issues since 2007. Her photo "Triple Take" won first prize in its category in WildCare’s 2010 Living with Wildlife Photo Contest. To see more of Janet's work, visit her blog about coyote behavior, personality, coexistence and advocacy coyoteyipps, and her website about wildlife in this area: http://www.urbanwildness.com
|
|||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||
Back to Top
|
|||||||||||||||||||||||||||||||||||||
love in the treesby Lucy Burlingham, WildCare Squirrel Team Leader Late winter and early spring are breeding season for tree squirrels in Marin. This ensures that young emerge during a time of plenty as trees begin producing buds, leaves and flowers after winter dormancy. This could explain an unusually large number of Western Gray Squirrels I observed recently around a house in Fairfax. Tree squirrels are normally solitary, but there were at least eight or 10 squirrels circling through the trees around the house and watching each other intently. The female squirrel is only in estrus and receptive to males for about eight hours on a single day during the reproductive season. Male squirrels therefore have to track the reproductive condition of females daily or they may miss their only mating opportunity. As the female is approaching estrus, males from all around cautiously approach to see if she is receptive. If she is not ready, they will be actively rebuffed with sharp claws and teeth. valentine’s day On the day of estrus, males travel to the nest of the female to await her emergence. The congregated males jockey for position near the nest and a clear dominance hierarchy appears. When the female emerges, the mating chase begins, during which she will mate with two to four males. Competition to gain access to the female is intense, numerous fights take place and injuries are common. A successful male may be interrupted during mating by a vicious bite to the haunches from a rival, or both mating squirrels may be knocked from the branch and suffer a long fall. The female usually mates with the most dominant males, but younger, low-ranking males often join in the chase. Since they have little chance of fighting their way to the female, why would they do this? The females sometimes “break away” from a branch where a male has attempted to trap her. This results in a single file of males in hot pursuit. Sometimes the males are so distracted by fighting with each other that the female is able to lose them. She finds a secluded position close to the ground and mates with the first male that finds her, usually a lower-ranking male. If the most dominant males carry the best genes, why would the female want to mate with a lower ranking male? Matings after a breakaway occur at sites lower to the ground and with less likelihood of being interrupted by other males. What females gain from a breakaway is the opportunity to mate in seclusion, near to the ground, with the decreased chance of attack that might result in physical injury that could endanger the future pregnancy. Cars are always a problem for squirrels, and in all the excitement of raging hormones, squirrels are paying even less attention to cars than they usually do. Please drive carefully and be on the lookout for crazed squirrels running across the road. After all the excitement dies down, the female again rebuffs any male that approaches her. She begins the pregnancy that will result about 45 days later in three to five blind, naked, tiny babies that will require her full care until they are 10 weeks old or older. During that time she will stay with them in a warm nest she has built (called a drey) and leave them safely asleep for periods of time each day when she goes out to forage. If they are lucky, you won’t see them until they are ready to begin playing in the trees. Sometimes they do get into trouble, though. If their mother is killed, they may crawl from the drey and fall from the nest prematurely. Sometimes they fall out of the nest even if their mother is around. If that happens, she will usually carry them back into the nest if she finds them. If you find an injured or orphaned wild animal, call WildCare (415-456-SAVE (7283)) to be sure it needs help, and to get advice about what steps to take. WildCare is licensed (but not funded!) by the state of California to care for wild animals. If the baby does need help, WildCare’s Foster Care Volunteers are trained to provide the proper care and specialized diet each species of wild animal babies needs to survive. Foster Care volunteers take home baby squirrels, opossums, raccoons, skunks, bats and even some songbirds until they are old enough to be reintroduced to their natural lives.
|
|||||||||||||||||||||||||||||||||||||
Back to Top
|
|||||||||||||||||||||||||||||||||||||
great gift ideas for February
|
