Thursday, July 31, 2008

Coexisting With Wildlife

The Puente Hills is surrounded by a large perimeter of urban edge (approximately 25 miles). This presents challenges to people living near or adjacent to the natural areas, as well to the plants and animals that occupy the open space. On the urban side of the urban/wildland interface, people living adjacent to natural areas often experience visits from wildlife. The smaller wildlife, such as rodents, raccoons, and skunks often go unnoticed; whereas larger mammals such as coyotes draw the attention of humans. This is not something that should alarm people, but instead should make people aware.

The Habitat Authority periodically receives calls from residents encountering coyotes and other wildlife, including neighborhoods that are more than a mile away from the Puente Hills open space. This morning we received a call about a coyote that was walking down a residential street in Whittier more than a mile from the nearest natural area. Coyotes are one of the most adaptable animals, occupying virtually every habitat type in North America, including urban areas. As with many other types of wildlife, coyotes are more commonly out from dusk to dawn, moving through urban areas along railroad tracks, greenways, parks, and drainage facilities. However, encounters do occur during the day.

Occasionally, people will experience a more personal encounter with a coyote, including the loss of pets, and very rarely an attack on humans. However, people should not be fearful of coyotes. Coyotes play an important role in the ecosystem, helping to keep populations of rodents (rats and mice) and other small mammals under control. Naturally coyotes are fearful of humans, however coyotes readily lose their fear of humans when people intentionally (or unintentionally) provide food/water or shelter for them, or otherwise do not try to deter them from visiting. It is not feasible to completely eliminate coyotes, but removing sources that attract coyotes can go a long way to avoiding a conflict.

It is unfortunate when a person loses a pet to a coyote, and this may elicit a very emotionally negative response from the pet owner towards coyotes in general. However, the coyote views the pet as one of many food sources, and this type of encounter is almost always preventable. People that live in areas with coyotes should not leave their pets outside at night. If a pet cannot be brought inside, then the pet should be kept in some type of an enclosure that other wildlife cannot get in to. In areas where the occurrence of coyotes is much higher, pets (especially smaller dogs and cats) should ideally be placed outside only while being supervised, even possibly during the day. For areas where coyotes are attacking pets, there should be a heightened awareness towards this behavior, and if necessary the appropriate wildlife authorities can be notified. Local authorities may investigate these occurrences, but they may not actively trap and remove coyotes simply in response to attacks on pets.

The presence of unwanted wildlife in urban neighborhoods (especially in yards) is often due to one or more factors caused by the residents themselves, in some instances knowingly. As noted above, the presence of small pets left outside is a big attraction for coyotes as a food source. Other things that attract coyotes include pet food that is left outside; unsecured garbage cans; ripened fruit that has fallen off of trees; shelter such as dense shrubbery; and water sources such as pet bowls, fountains, ponds, and swimming pools. It may be difficult to remove all attractants (such as ponds and swimming pools), however at the very least people should not provide food to coyotes or any other type of wildlife. Besides it being a bad idea ecologically, it is against the law to feed or otherwise provide food to specific types of wildlife. This includes ground squirrels, coyotes, raccoons, skunks, and opossums; all of which are common in urban areas.

As noted above, coyote attacks on humans are rare. Of those attacks that have occurred to humans, a significant number of the attacks have been towards small children. Coyotes can view small children as prey animals (particularly when a child is crouched down while playing). Particularly in areas with a higher occurrence of coyotes, children should be supervised by an adult at all times while outside. If you are approached by a coyote, or even if you see one in your yard, every effort should be made to frighten the coyote away and make the coyote fearful of humans. Make yourself as big as possible by raising your arms. Make loud noises to startle the coyote. Spray the coyote with water if a hose is available. If the coyote still will not leave, then throw an object such as a rock as near the coyote as possible but not at its body. If this still does not work, then throw an object at the body, though not at its head.

If a coyote does not retreat after trying all feasible measures, if a coyote bites a human, or if one otherwise truly acts aggressively, then the appropriate wildlife authorities (including Animal Control) should be contacted immediately. If necessary and feasible, then the appropriate authorities may determine that elimination of a coyote is warranted. Simply seeing a coyote in a residential area is not a reason to be alarmed, and does not justify removal, however it should make people aware that coyotes are present, and what can be done to reduce the likelihood of a closer encounter. Also, there is a difference between a coyote that is being bold and one that is acting aggressively. A coyote coming into a yard looking for food is acting boldly, but is not necessarily exhibiting aggressive behavior towards humans. The difference between bold and aggressive may be a fine line at times, but people should be aware that the sheer presence of a coyote is not a cause to call for its removal, especially for people living very near to natural areas. Coyotes that have become bolder have done so by losing their fear of humans. Even though a bold coyote may not be a cause for removal, its reasons for being bold should be addressed. Do not simply ignore a bold coyote.

There are many resources available for information and guidance on coyotes and other wildlife. Please visit our website ( for more information on coexisting with wildlife. In addition, the websites of the California Department of Fish and Game, and many other agencies and organizations provides valuable information. If you are interested in a DVD on coexisting with wildlife or other literature, please contact the Habitat Authority at (562) 945-9003. A ranger or other staff member would be pleased to personally visit people with questions or concerns, or alternatively we could mail materials to you.

Friday, July 18, 2008

Red skimmer

Yesterday I photographed this red skimmer dragonfly in Sycamore Canyon. Dragonflies and the closely related damselflies are highly beneficial predatory insects. They are responsible for eliminating large numbers of mosquitoes, as well as other pesky insects. Dragonflies such as the red skimmer are very specialized hunters. They have large compound eyes for spotting their prey, and sharp mouthparts for cutting up insect prey. Dragonflies are skilled at maneuvering through the air, as a result of their four powerful wings that move independently. This allows dragonflies to move both forward and backward. Their legs are not suitable for walking, but instead are used to hold their insect prey that is captured during flight.

Dragonflies and damselflies are strongly tied to aquatic environments. Their larval stage (referred to as naiads) develop in the water. The naiads themselves are aquatic predators, capturing things that include insects, tadpoles, worms, and small fish. Worldwide there are 5,000 known species of dragonflies and damselflies, with approximately 450 occurring in North America.

Wednesday, July 2, 2008

Poison oak and's all relative.

I am a botanist by education (and work experience), and so I have always enjoyed studying the relationship of one plant to another. In trying to get non-botanists to be interested in plants, a great teaching tool is to relate plants commonly used by people (food, landscaping, etc.) to native plants that one will see in natural areas. Poison oak is a great example. Hopefully those of you that are frequent enough visitors to the Puente Hills and other natural areas will recognize the attached photo as the oily, reaction-causing leaves of poison oak (leaves of three…leave it be!).

Here is a bit of background on plant taxonomy.....two closely related species of plants occur in the same genus (genera). For example, white sage, black sage, and purple sage are all in the genus Salvia. Similarly related genera are placed in the same plant family. Plants of the genus Salvia, along with other “mints”, are placed in the plant family “Lamiaceae”. Getting back to poison oak....this plant is placed in the family “Anacardiaceae”. Other representatives of this family that occur in the Puente Hills include native plants such as lemonadeberry, laurel sumac, and skunkbrush, and non-native plants such as the Peruvian pepper tree. Many species in this plant family contain a type of oil called “urushiol”, which is particularly abundant in poison oak (genus Toxicodendron). This is the oil, which for people that are sensitized to, will cause the characteristic delayed allergic reaction. Up to 30% of people have no allergic reaction when in contact with the oils from poison oak; however most will become sensitized to it with repeated exposure.

What many people find interesting is to know what common food items occur in the same plant family, and are therefore more closely related to poison oak. These include the pistachio, cashew, and mango. The urushiol oil is found in the nut shell of the cashew fruit (though not in the cashew fruit itself), and in the mango plant sap as well as the skin of the mango fruit. With the respect to the mango plant, breaking the vine of a green mango fruit will produce a fine aerosol of sap that causes severe reactions in previously sensitized individuals. The mango fruit skin has a lesser concentration of urushiol, though still with some potential for the delayed skin rash with more sensitive people. However, the edible part of the mango fruit itself does not cause these reactions, and is one of the most popularly used fruits worldwide; used for food, juice, flavoring, fragrance, and color. The mango is an excellent overall nutrient source, including dietary fiber, carbohydrates, and antioxidant vitamins.

Here is a great game to play. The next time you are eating a meal, think about each plant product that you are eating, where it comes from, and what it might be related to. Is it a fruit? If not, what part of the plant does it come from? Is it a root? A stem? A leaf? Dinner will never be the same again!