Puente Hills Nature

Something is bugging our oaks...

2012-02-10T15:42:00.000-08:00

Over the last few years, I’ve noticed that the large coast live oak trees along Turnbull Canyon Road appear to have small patches of dead leaves on them, but the trees appear to be healthy otherwise. For a while, I dismissed the dead leaves as a symptom of drought. But as I was made aware of a devastating new pest that is affecting oaks in San Diego County, called the gold-spotted oak borer, I’ve been paying a bit more attention to trees that appear distressed. Although there could be several things causing the dead leaf patches on our oaks, including other insect pests and fungi, I became concerned that these oaks could perhaps be affected by the gold-spotted oak borer. So, I examined some of them closely.

While gold-spotted oak borer attacks can cause thinning of the tree crown and die-back of twigs, none of the trees appeared to exhibit any of the classic symptoms along the trunk, such as weeping or staining, or tiny D-shaped exit holes. What I did find was at the point where the dead twigs met with the live tree branch, under the bark there was a pattern etched in the tissue spiraling around the twig, with dark powdery “frass”inside the tunnels (see photo) – I even found a tiny larva in one! This indicated that the damage could be caused by an insect called the oak twig girdler. It is similar to the gold-spotted oak borer, in that they are related – gold-spotted oak borer’s scientific name is Agrilus coxalis, and the oak twig girdler’s scientific name is Agrilus angelicus. Also, both attack the tree’s tissue just below the bark, causing the growth beyond the attack site to die. However, the gold-spotted oak borer attacks the trunks of trees, whereas the oak twig girdler only attacks the smallest twigs at the ends of branches where new growth is happening. That is why the gold-spotted oak borer is much more of a threat, because when it attacks the trunk tissue, it prevents nutrients from reaching the rest of the tree (branches and leaves).

The larva I collected is being sent to the Los Angeles County Department of Agricultural Weights and Measures for entomologists to confirm whether it is the oak twig girdler. Fortunately, the oak twig girdler is not considered to be a significant impact to tree health. But the presence of these insects may be a sign that our oaks are under some stress, as the oak twig girdler is thought to be attracted to trees weakened by drought.

**UPDATE: The Los Angeles County Entomologist confirmed that this is likely the oak twig girdler, and that it is not a cause for concern. He also mentioned that this is a native species.

Should you be afraid of bobcats?

2011-12-28T12:09:00.000-08:00

We at the Habitat Authority have gotten several calls over the years from local residents or hikers asking this very question. It is understandable for people to be afraid of things they are not familiar with, and given the relatively reclusive and secretive nature of bobcats, most people never see bobcats.

Some people are afraid of bobcats because they associate them with mountain lions. It is true that they are both wild felines. However, bobcats are much smaller than mountain lions (about 10 times smaller), and are only about the size of a beagle or about twice the size of an average housecat. (They also look quite different, with bobcats having short “bobbed” tails and a striped or spotted body, whereas mountain lions have a very long tail and are a uniform tan color). Given their small size, they also eat smaller prey than mountain lions; bobcats generally eat rabbits or rodents, while mountain lions almost exclusively eat deer.

Although there are rare reports of mountain lion attacks on people (none in the Puente Hills area), there are almost no records of bobcat attacks on people. The few credible reports that do exist generally have to do with a rabid bobcat, which is quite unusual. No reports of rabid wildlife of any kind have been reported to the Habitat Authority.

Bobcats, like mountain lions, generally avoid people and areas inhabited by people. They tend to be found less often along trails with higher recreational activity, and they often shift their activity to occur at nighttime in areas frequented by people in an effort to avoid them. Bobcat home ranges occur much more frequently in natural habitat compared to areas within or near developed areas.

If you see a bobcat in your neighborhood, it probably means that you have a lot of natural vegetation in the area. If there are a lot of rabbits or rodents in your neighborhood gardens, that might also attract bobcats. If you want to keep bobcats or other wildlife out of your yard, consider installing fencing around your immediate use area, make sure to clean up fallen fruit or other potential food items (trash, bird seed) that might attract rodents, keep small pets indoors and/or closely supervised, and never intentionally provide food or water to wildlife.

There is no reason to fear bobcats, but bobcats have plenty of reasons to fear us. In most remaining natural areas in southern California, bobcats have to face many challenges in order to survive. One major challenge is crossing numerous busy roads safely. Another challenge is not becoming infected with diseases which could be passed on from other animals or even domestic pets, and not eating rodents that have been poisoned; rat poisons contain anticoagulants and are shown to have a possible association with a disease called mange. Another challenge is finding large enough patches of habitat that are relatively free from human disturbance in order to live and rear their young.

If you do see a bobcat, you should consider yourself very lucky! Seeing a bobcat is a good way to remind us of the wildness that is still present in our area.
(Photo credits: top - Doug Wolfe, drawing - Cougar Network, time-stamped - Puente Hills Habitat Preservation Authority)

What’s Lurking in your Firewood?

2011-12-01T14:47:00.000-08:00

With winter just around the corner, you may be starting to buy firewood. But besides the usual critters that hang out with firewood, such as spiders or scorpions, there may be another, much more dangerous threat that is too small to see. That threat is from a small beetle, called the gold-spotted oak borer. As its name suggests, it bores into oak trees, and it eats away at their critical vascular tissue, eventually killing them. As of 2010, this beetle has killed an estimated 21,500 trees covering 1,893 square miles in San Diego County in forests, parks, and residential landscapes.

Fortunately, there are no known occurrences of the gold-spotted oak borer in Los Angeles or Orange Counties. Unfortunately, it is known to occur in not-too-distant San Diego County. If firewood from oak trees in San Diego County is transported elsewhere, it could spread the gold-spotted oak borer into new areas. When firewood is harvested, the beetle may be present in its larval stage, feeding off of the oak’s tissue beneath the bark. When that oak that becomes firewood, the beetle is transported along with the firewood. By late spring, the beetle transforms into its adult stage, with wings, and it flies out of the wood to find new oak trees on which to lay eggs. These eggs hatch into larvae, which bore into the new oak tree, and the cycle begins again.

Currently, there is no known effective remedy or treatment for the gold-spotted oak borer. Sometimes infested oak trees must be killed before others are affected. Our native coast live oak trees not only help to define the beauty and naturalness of the Puente Hills area, but also provide food and shelter for numerous invertebrates, birds, and mammals. Their importance is reflected by the fact that they are considered a protected tree species by Los Angeles County, and oak woodlands are also protected by the State. Oaks also provide shade for homes, and can even add to property values. Oaks continue to be lost to land development and other impacts, and it is important to retain and protect the remnant patches that remain. Therefore, the best hope we have in protecting our oak trees from further loss due to the gold-spotted oak borer is to prevent it from getting here in the first place. Please, check on the source of your firewood before you buy it, and avoid buying oak firewood from San Diego County. Or, if you have already purchased wood from there, burn it right away and burn it thoroughly. Help protect the beauty and natural value provided by our native coast live oaks.

For more information, visit these websites:
www.ucanr.org/sites/gsobinfo
www.cisr.ucr.edu/goldspotted_oak_borer.html

(photo credit for picture of gold-spotted oak borer: http://www.ucanr.org/sites/gsobinfo/)

(photo credit for picture of firewood: http://firewood.ca.gov/)

Mixed Nuts

2011-11-04T14:49:00.000-07:00

As some of you may be aware, parts of the Puente Hills Preserve support a rare species of native tree, the Southern California black walnut (Juglans californica). These Puente Hills are one of the handful of places in Los Angeles County where this tree is found, and it generally only grows on more moist north-facing slopes or in shady canyons. It is often found growing with another native tree, the coast live oak. In the Preserve, it can be found in the Powder Canyon and Hacienda Hills areas. The presence of walnut woodlands in the Preserve is one of the reasons that the Puente Hills was recently selected for possible inclusion in a new National Recreation Area that could encompass parts of the San Gabriel Mountains and Watershed.

The native black walnut is similar to the cultivated walnut that we buy at the grocery store, in that they both produce walnuts (although the native is smaller). One such cultivated walnut is the English walnut (Juglans regia), which is related to the native black walnut – since they are related, they can and sometimes do hybridize with each other. In the early 20th century, horticulturalists were conducting experiments hybridizing black and English walnuts, including Luther Burbank (in Santa Rosa, Northern California) and the University of California Department of Agriculture. The latter planted one of these hybrid trees in 1907 in the City of Whittier, known as the Paradox Hybrid, where it still stands today at about 14 feet tall and about 100 feet in diameter – an enormous, gorgeous tree (see photo below)! It is actually a Registered State Historic Landmark Number 681 (located on Whittier Boulevard near the intersection with Mar Vista).

If you hike in Powder Canyon and look closely at the walnut trees you may notice that a few of the trees are much larger, and have much larger leaves, but have very few fruits (often none). That is because some are the native black walnut (the smaller trees with smaller leaves and lots of fruit - at left) and some (possibly 5%) are the black-English walnut hybrid (the larger trees with larger leaves and few fruit - at right). The bark of the native black walnut is very furrowed or “grooved”, whereas the hybrid has either smooth bark (like the English walnut), or bark that is somewhere in between. So how did these hybrids get there? One possibility is that they are the result of black walnuts hybridizing with a nearby English walnut that was planted on someone’s property, perhaps one of the commercial walnut orchards that used to be more prevalent in the past. Another possibility is that these were planted as acorns from a hybrid, possibly even from the Paradox Hybrid in Whittier. This latter seems likely, considering that several resources have noted that the second generation hybrids (meaning those trees grown from seeds of the hybrid) bear very few fruit, which is the case for those hybrids seen in Powder Canyon.

Regardless of their native or hybrid status, the walnuts in the Preserve provide important food and shelter resources for many species of insects, birds and mammals, and are a beautiful and shady addition to our trails.

Cozy Camera

2011-10-07T15:07:00.000-07:00

Surprise! That is what I think every time I download the digital photos from our motion-sensor cameras located throughout the Preserve, because I never know what fun surprising wildlife photos I’ll see. But sometimes I’m also surprised by what I find inside the camera itself. Occasionally I’ll find a spider making a web, or a colony of pincher bugs. But this week I found something quite surprising – a nest! And no, not a bird’s nest; nesting season is pretty much over by now for birds, generally ending in August or September. It was a mouse nest! I believe they are common deer mice based on their orange-brown fur on the top of their bodies, and the white fur on their underside, as well as their size and ears.

Deer mice can reproduce almost any time of year, especially in our moderate climate, and use a variety of places to build nests. Apparently there was just enough of space for them to wedge into the metal box which houses the camera, and build a fluffy, cup-shaped nest. Nests are often constructed out of grasses, moss, wool, fibers, and thistle down. This nest appears to be constructed mostly of pappus from thistle seeds (“thistle down”) – this is the fluffy stuff that allows the seed to be carried off by the wind. I caught both of them as they were still constructing the nest, and when I went back to check a few days later, the nest was completed into a sphere with a hole in the top – and the female nestled inside (the male ran out of the box as I opened it). Their gestation period is about 3 weeks, so I’ll keep checking over the next few weeks to see if there are any baby mice.

The Young and the Restless

2011-08-22T08:57:00.000-07:00

Summertime means lots of different things to different people. Here on the Preserve, one thing it means is we get to see the young animals that were born this spring and are now roaming about. Some are still with their parents, and will be through the fall. Our motion-sensor wildlife cameras have picked up several young animals that we'd like to share with you.

This fawn (on the left) photographed in Sycamore Canyon is probably a few months old in this photo, and is still young enough to still have its spots for camoflauge from predators. Their main predator here on the Preserve is likely the mountain lion, which are sometimes seen in Sycamore Canyon. Deer are very common here probably due to the proximity to the irrigted lawns at adjacent Rose Hills Cemetery, which is probably why the lion is seen here sometimes, but unfortuntely we haven't gotten a mountion lion photo yet. If you see a lion anywhere on the Preserve, contact Shannon Lucas at the Habitat Authority so we can add it to our database (slucas@habitatauthority.org).

These young ground squirrels (the two on the left) are following their Mom near the entrance to the Colima Tunnel along the Arroyo San Miguel trail, although its unlikely they will go all the way through the tunnel.

This coyote was photographed just uphill from the Colima Tunnel. It appears to be young coyote due to its relatlvey smaller size and especially its fluffy coat of fur. It is possible that its parents have taught it to travel safely across Colima Road by using the tunnel, as it is heading in that direction, and there is a photo of a coyote's tail heading into the Tunnel (from another camera) only one minute later. This tunnel has been used by several wildlife species, including deer, coyote, and bobcat, to travel safely across Colima Road and avoid being hit by vehicles; unfortunately, bobcats are not seen as frequently here as they once were, but roadkill bobcats and other large mammals are often seen as roadkill at the top of the hill on Colima Road, indicating that there is not a safe way to cross Colima Road at that location. Despite posted speed limits and wildlife crossing signs, roadkill are common, so watch your speed and watch for crossing wildlife!

Chick Flicks

2011-04-19T13:25:00.000-07:00

For the last two years during the month of April, we've shared photos of the red-tailed hawk chicks and great horned owl chicks in nests within the Preserve's Core Habitat (an area that is off-limits to the public to provide a refuge for wildlife). This year, with our new digital video camera, we now have some short videos to share!

The first video is of the three red-tailed hawk chicks with their mother - after she stops looking annoyingly at me (even though I'm several hundred feet away!) she continues to feed her chicks. Keep an eye out for the two chicks in the back that appear to be fighting over the leg of some unknown small animal that is now their lunch. The second video is of three great horned owl chicks and their mother - toward the end of this video, the mother moves away from the chicks, and two of them try to awkwardly follow her.

As you will see, the owl chicks are much larger than the hawk chicks, and are closer to the size of their mother, whereas the red-tailed hawk chicks are still very small. That is because great horned owls often lay their eggs earlier than other raptors, which means they hatch sooner, so they are more developed at this point in time than the hawk chicks, which likely only hatched a few weeks ago. The great horned owl chicks will soon be losing their fluffy white feathers, looking more like mom and dad, and start walking out onto the branches of their nest tree. Hopefully more videos to come!

Roadkill and Rodenticides

2011-03-22T14:17:00.000-07:00

What on earth do these two things have in common? Both obviously involve dead animals. But roadkill are killed directly by vehicles on roads. Rodenticides also directly kill rodents (such as rats in homes or gophers on lawns when they eat the rodenticide) because the main ingredient is an anticoagulant, which prevents blood from clotting and eventually causes the animal to die from internal bleeding. However, rodenticides can also indirectly kill or harm other animals, such as bobcats or hawks, which can become poisoned when they eat rodents that have eaten rodenticide.

Researchers at UCLA and the Santa Monica Mountains National Recreation Area are studying a possible link between indirect rodenticide poisoning of bobcats and a disease called mange. They have noticed that bobcats that have died with mange have all had concentrations of anticoagulant compounds in their liver. Please check out www.urbancarnivores.com to learn more about the study and alternatives to rodenticides. The Habitat Authority has agreed to assist in this research effort by collecting tissue samples from dead bobcats. The tissue is sent to UCLA, where the researchers determine whether the bobcat has mange and/or whether it has traces of anticoagulants in its system (by testing the liver).

Last week, two roadkill bobcats were found along Colima Road within days of each other in almost the same location, and samples were collected for the UCLA study. In addition, genetic material from these samples will also be shared with the U.S. Geological Survey, which is conducting a regional study of large mammals in southern California to determine dispersal patterns. So, hopefully these bobcats will not have died in vain. It is possible that they can be used by scientists to determine whether anticoagulant rodenticides cause mange in bobcats. It is also possible that they can be used by scientists to determine where our bobcats originally dispersed from, and how they are related to other bobcats in southern California. In the meantime, the Habitat Authority is studying wildlife movement across Colima Road in an effort to reduce roadkills over time, helping to maintain habitat connectivity throughout the Puente-Chino Hills Wildlife Corridor.

You can also help by avoiding the use of rodenticides, and by reporting any sick, injured or roadkill bobcats to the Habitat Authority by contacting the Ecologist at 562-201-2062 or slucas@habitatauthority.org.

Microfauna

2011-01-28T16:52:00.000-08:00

Much time and attention is devoted to what Biologists commonly call “charismatic megafauna” – namely, the larger and cuter animals, such as hawks or bobcats. Plus, megafauna are generally easier to spot when out on a hike or bike ride. However, there are numerous forms of “microfauna” in the hills worthy of some attention.

I recently found one such specimen while weeding a recently planted restoration area. As I was pulling out a non-native mustard seedling, I saw a worm…or what I thought was a worm. Strangely, this worm had arms and legs! So I picked it up, and sure enough, it was no worm, but a very tiny salamander – a black-bellied salamander. They really are about the size of an earthworm (generally no longer than 2 inches and about the same diameter), but with tiny legs, a tiny head with eyes, a reddish topside with a dark stripe, and a mottled gray underside.

They also like to live in moist places like worms – that is because they are a type of “lungless” salamanders, meaning that they breathe through their skin, which needs to remain moist. So, you are really only likely to see them near creeks or shady woodlands, and only in the wet part of the year – they retreat underground during the dry season.

Black-bellied salamanders are endemic to coastal Southern California, but it is not considered a rare species. During a study of the Puente-Chino Hills from 1998 to 2000, only three species of salamanders were found – black-bellied, arboreal, and garden slender salamanders. Of the three, black-bellied salamanders were the most common, and most of them were found in Powder Canyon. But the study also found it sometimes difficult to tell the difference between black-bellied and garden slender salamanders. Either way, they are a good reminder that sometimes we need to stop and appreciate the little things!

Ramblin' Coyotes

2010-09-14T17:15:00.000-07:00

Fall is here, and many of the animals born in the spring are now juveniles or adults, and are starting to fend for themselves. Coyotes are born generally from March to May, are weaned in about 6 weeks, and are self-sufficient juveniles after 5 to 6 months. Some juvenile coyotes stay with their family as a pack, but others may become solitary, dispersing away to find their own territory. Reasons why an individual will disperse away from a pack are generally due to the availability of food resources or the density of coyotes in the area. Although dispersal can happen at any time of year, approximately half of them occur in the fall. Being young and naïve, these juveniles may sometimes wander into inhospitable habitats, such as residential neighborhoods with busy roads and other hazards. Coyotes will often travel along habitat “edges” or pathways, such as roads, powerline easements, railroad tracks, and drainage courses. Some juveniles may have been raised in urban areas, taught by their parents to eat human-related food. Urban areas are tempting for coyotes, as they provide abundant food sources for the omnivorous and adaptable coyote. Although most coyote diets consist of small mammals (such as rodents and rabbits) and vegetation (such as fruit), approximately ¼ of the urban coyote’s diet comes from human-related food. This can include fallen fruit from trees and gardens, trash, pet food, and even sometimes pets themselves; however, recent studies have shown that pets, especially domestic cats, are generally a very small proportion of coyotes’ diets, ranging anywhere from one to six percent. Sometimes people even intentionally feed coyotes. But if food sources are deliberately, or even accidentally, provided by people these young coyote learn to associate human neighborhoods with food and may develop a reliance on these unnatural food sources, increasing their interactions with humans and reducing their natural fear of humans. The best way to avoid human-coyote interactions is to prevent them by keeping coyotes wild – here’s how:

• Fence your backyard. Fences that are 6 feet high and 6 inches underground are an effective means of keeping wildlife out, especially coyotes. More information about a specialized coyote proof fence can be found at http://coyoteroller.com/Products/features.htm
• Secure garbage cans.
• Do not intentionally provide food or water for wildlife.
• If you have fruit trees, pick ripe fruit from the tree on a regular basis, and pick up fallen fruit from the ground.
• Do not leave dog or cat food outside.
• Keep pets indoors, especially at night.
• Keep chickens, turkeys and goats in covered pens.
• Clear away bushes and dense weeds near your home where coyotes find cover and smaller prey to feed on.
• Eliminate water sources that may attract wildlife.
• Install outdoor lights triggered by motion sensors to frighten away wildlife at night.

Please visit the following links for more information on coexisting with wildlife:

• California Department of Fish and Game website for more information on coexisting with wildlife: http://www.dfg.ca.gov/education/living.html
• CA Department of Fish and Game’s Keep Me Wild Campaign: http://keepmewild.org/
• CA Department of Fish and Game's brochure about coyotes: http://www.dfg.ca.gov/keepmewild/docs/coyotebrochure.pdf
• Project Coyote: www.projectcoyote.org

Show and Tell

2010-08-04T09:39:00.001-07:00

Its been almost 8 months since we installed motion-sensored wildlife cameras in the Arroyo Pescadero area of the Preserve, and I thought we should share some highlights so far. These cameras are triggered by movement, including wildlife, people, and vehicles – sometimes even the wind moving the vegetation. Movement triggers an infrared sensor which then triggers the camera to take a digital photo. As you will see, the photo also records the date and time of the photo for reference. At night, an infrared flash will also be triggered, which helps to illuminate the subject enough to identify it, (although the photo is black and white instead of color). The infrared flash is less visible than a standard white flash, which is less disturbing to wildlife, but you will see that some wildlife still notice it.

Some of you have noticed these cameras, despite efforts to camouflage them, as shown in the photo below.

Some of your pets have even noticed them.

Even wildlife, such as this coyote in the Core Habitat (no public access), have noticed the cameras.

We have seen a good diversity of large and small mammals, both day and night, such as deer, skunk, and bobcats.

Although bobcats are thought to mostly be out from dusk until dawn, this one is out at two o’clock in the afternoon!
This spring, we have gotten many photos of ground squirrels, birds, and rabbits. Check out this photo of two rabbits fighting – bet you’ll never see them as quiet and shy creatures again!

We hope to share more highlights in the future, as these cameras will keep going through November, as part of a year-long study of wildlife in the area.

MORE CHICKS!!!

2010-04-29T17:59:00.001-07:00

Last April I posted photos of red-tailed hawk chicks. This year, I’m sharing photos of great horned owl chicks. As you can see, these chicks are already very big – almost as big as their parents – which means they are probably getting ready to leave the nest soon.

Great horned owls are one of the earliest breeding raptors, sometimes laying eggs as early as late December or early January. The eggs hatch after about one month of incubation, and then the chicks generally start to wander from the nest onto nearby branches (which is why they are called “branchlings” at this stage) anywhere from 6 to 7 weeks of age, and start flying around at about 10 to 12 weeks.

Great horned owls generally don’t build their own nest, but rather take over an old nest from another bird species, such as a red-tailed hawk. In fact, this same nest last year was used by ravens which produced several chicks – but it looks like the great horned owls got to it first this year!

Notice that these chicks are wide awake during the day, despite the presumption that all owls are strictly nocturnal. While some owls are only active at night, great horned owls are known to be somewhat active and can even be seen flying around during the daytime, although they are most active and hunting at night. Stay tuned for possible additional photos of the branchlings moving away from the nest soon!

What are those white circles?

2010-03-12T11:54:00.000-08:00

If you are a regular visitor to either the Arroyo Pescadero loop trail or the Arroyo San Miguel trail, you’ve probably seen numerous white circles along these trails from time to time. Accompanying these circles are orange signs reading “Please Stay Away From White Circle, Scientific Study In Progress”. But what are these circles, and why stay away from them?

These white circles are track stations which are part of a Habitat Authority wildlife study, established to attract resident wildlife to determine the frequency and diversity of animals in the area. The white powder consists of calcium carbonate (a natural substance that is the main component of limestone), and is the same substance used to create the white lines on baseball and other sports fields. The rock in the center of each circle has a small amount of a scent lure designed to attract animals, particularly carnivores. So, when an animal walks near the track station and smells the scent lure, it walks over the white powder to get a closer whiff of the rock, leaving its footprints in the powder. This is a method used commonly by wildlife biologists, and has been used in the past to study wildlife throughout the Puente-Chino Hills.

Wildlife tracks we have seen over the past five months of the study include coyote, bobcat (in photo at right), striped and spotted skunk, mule deer, ground squirrel, raccoon, cottontail rabbit, and various birds and small rodents. We have also seen many domestic dog tracks, and a few human footprints, indicating that some people either do not read the signs or do not have their dogs on leash. Dog and human tracks may obscure tracks that were left previously by other wildlife, affecting the data and study results.

So, if you see the white circles along the trail, feel free to look and see what kinds of wildlife may have left their tracks, but please try not to leave tracks of your own (or your dog’s). Thank you!

A Native Albino

2010-02-10T13:52:00.001-08:00

For those of you that have been out on the trails over the last month or so (when it wasn’t raining, that is!), you have likely noticed one of our early blooming native plants – fuchsia-flowered gooseberry (Ribes speciosum). It is a woody shrub with spiny stems, glossy and rounded leaves, and chock-full of gorgeous raspberry-colored flowers that dangle down like inverted tear drops with legs. Chances are that if you are near a fuchsia-flowered gooseberry that is in full bloom, you may get “buzzed” by an angry hummingbird that has claimed the bush for its nectar supply. At the base of the flower, a small spherical fruit will develop that will be covered in spines as well. These berries were eaten by Native Americans and are related to cultivated gooseberries as well as currants, which are similar but the fruits are not spiny.
But last month, a local hiker and native plant enthusiast, Cynthia Guthrie, alerted me to the presence of an albino fuchsia-flowered gooseberry on the Preserve in Turnbull Canyon. This plant has all of the same physical characteristics of other fuchsia-flowered gooseberries, but its flowers are greenish-white instead of a reddish-raspberry color. I inquired with other botanists to see if they had seen this elsewhere and none had, so I sent off a sample to an expert at Humboldt State University, Michael Mesler, who is writing the key for the gooseberry family in the revised Jepson Manual (one of the primary sources for California plant identification). Although he had not seen albino forms of this species before, he had seen it in other related species. Apparently the albino condition is due to a mutation in this individual shrub, which has somehow removed an enzyme involved in the production of the normal pigment color. It will be interesting to see if this mutation carries over to the next generation of plants in the area – keep your eyes peeled for any more white or light pink colored fuchsia-flowered gooseberries next spring!

A Tale of Two Tunnels

2010-01-28T16:07:00.001-08:00

It’s official. After years of monitoring at the Harbor Boulevard Wildlife Underpass, the results are in…and the news is good!

The underpass was built in 2006 to maintain a viable means for wildlife to move between habitats on both sides of Harbor Blvd., helping to sustain the Puente-Chino Hills Wildlife Corridor. Now, the underpass is a big success, with many different species of wildlife using it on a regular basis to cross under Harbor Blvd. By doing so, these animals avoid the risk of becoming roadkill while crossing Harbor Blvd. at the road surface.

The most interesting findings from the long-term monitoring study were that (1) mule deer used the new underpass almost immediately, which is unusual compared to other underpasses studied, and (2) that coyote roadkill had decreased by approximately two-thirds compared to before the underpass was built. In addition to mule deer and coyote, which were frequent users of the underpass, other species observed included striped skunk, raccoon, and desert cottontail rabbit, and even bobcats which were rarely detected until the last part of the study. Researchers at CSU Fullerton, who conducted the study, believe that some of the wildlife, especially coyotes, may have taken a few years to “learn” to use the underpass, and now that they have done so are not becoming roadkill as much as they were in the past.

Further west, along Colima Road, there is another underpass; however, this one has existed for a long time as it was built for oil production transport before the area became a Preserve. A previous study conducted in 2001 and 2002 found that many different wildlife species also used this underpass, similar to those in the Harbor Blvd. Underpass, with bobcat, coyote and mule deer being the most frequent. This study also found that wildlife use of the Colima Underpass did not change substantially after the area was opened to public use and the underpass was part of the public trail system.

The Colima Underpass is being studied again this year by the Habitat Authority in an effort to see how wildlife activity and usage has changed over the last decade of public use and habitat restoration efforts, and to provide more baseline data for other projects that may occur in the area. But preliminary results indicate that wildlife usage remains high, with coyotes and bobcats seen as frequent visitors to the underpass, as well as skunks and rabbits. The maintenance of this underpass may be critical to maintaining habitat connectivity on both sides of Colima Road, and allowing for wildlife movement with fewer roadkill.

'Tis the season for mistletoe and "holly"

2009-12-22T17:35:00.000-08:00

Plants play a big role during the holiday season, from Christmas trees to Poinsettias, holly and mistletoe. Our hills are also celebrating the season with some of these plants.

One of these is not hard to find: Toyon. It is also sometimes called “Christmas berry”, and when you see its bright red cluster of berries this time of year its easy to see why. Settlers to California compared toyon to holly, which is not native to our region, and apparently used it for Christmas decorations instead. A few benefits of using toyon over holly is that its leaves aren’t nearly as prickly, and the berries are not toxic if accidentally ingested. (However, keep in mind that collecting plants from the Preserve is not allowed.) As some of you may have heard, “Hollywood” was actually named after the toyon bushes that grow in the Hollywood hills. Toyon berries serve as an important food source for birds this time of year, and were also eaten by Native Americans.

Another seasonal plant can be a bit harder to find: Mistletoe. Commercially-grown mistletoe is likely the kind that is native to Europe, but the mistletoe generally seen growing here in our sycamores and walnuts is native. Mistletoe is a hemi-parasitic plant, meaning that its roots grow into a tree or shrub which it gets nutrients from, but mistletoe is also green because it has chlorophyll, so it can make its own food as well. The scientific name for the type that grows here, Phoradendron, actually means “tree thief” in Greek. Mistletoe is also evergreen, but you generally don’t see it until the winter when deciduous trees lose their leaves, like in this picture of a local black walnut. Generally mistletoe does not kill the tree that hosts it, but if there are too many mistletoe plants in one tree it could weaken it and make it susceptible to other diseases, fungi or insects, which may eventually kill the tree. So the next time you’re on a hike with that special someone, peek up into the trees and maybe you'll find some mistletoe!

Recent wildlife sightings

2009-12-18T17:35:00.001-08:00

Earlier this week, a Peregrine falcon was seen hanging around the Core Habitat area of the Preserve, just west of Arroyo Pescadero. At first glance these birds look like a smallish hawk, such as an Accipiter (i.e. Cooper’s hawks) or a Buteo (i.e. red-tailed hawks). But the Peregrine falcon has a distinctive black cheek patch and black and white chest barring, as well as the tapered body shape typical of falcons (see photo taken by Robb Hamilton, regional bird expert). Peregrine falcons can be year-round residents in the western U.S., but many migrate farther north to Alaska and northern Canada in the summer, and to South American in the winter. They actually have one of the longest migrations of any North American bird, potentially migrating more than 15,000 miles in one year! Peregrine falcons were placed on the Federal and California Endangered Species Lists in the 1970’s due to population crashes from the pesticide DDT, which weakened egg shells. However, since the ban of DDT, Peregrine falcon populations have recovered so well that they were removed from the Federal list in 1999, and from the California list just this past month in November 2009. However, they are still protected by other state and federal laws, such as the Federal Migratory Bird Treaty Act. They often nest on cliffs, but also now nest on ledges of tall buildings and sky scrapers in urban cities. It is likely the Peregrine observed in the Preserve is a migrant just passing through, but we could only be so lucky if it decided to stick around and set up a nest this spring – we’ll be keeping an eye out for sure.

Another interesting wildlife sighting happened just today – I observed a gray fox in upper Turnbull Canyon, not more than 100 feet below a road with residences. It was alone, and grooming itself before curling up to nap near the edge of a large prickly-pear cactus patch. Gray foxes are native species, as opposed to the red fox which was imported for sport hunting and fur trapping. Gray foxes are often shy and elusive, and so are not seen nearly as often as coyotes. They are also fewer in number than coyotes. However, gray foxes are similar to coyotes in their feeding habits (omnivorous) and activity times (usually from dusk to dawn). They even look similar to coyotes at first glance, but are smaller, have proportionally larger ears, and have a reddish color under their chin and body (but are mostly gray and brown on top and on their tail). Unfortunately, it was too far away for me to take a good photo, but here is one from Calphotos (calphotos.berkeley.edu) for reference (photo credit: Gerald and Buff Corsi © California Academy of Sciences).

Cactus wren update - reasons for hope and caution

2009-09-28T13:13:00.000-07:00

Almost precisely two years ago, former Habitat Authority Ecologist Dan Cooper posted a blog lamenting about his observations of cactus wrens, or the lack thereof (see post dated September 13, 2007 at http://puentehillsnature.blogspot.com/). In his blog, he noted that many sites where he had observed cactus wrens in the late 1990’s appeared to be unoccupied in 2007. I’m happy to report that in 2009, things seem to be looking a bit better than initially thought, but there are still reasons to worry about the species.

This past spring, The Nature Conservancy initiated a regional study to determine the distribution of coastal cactus wren in Orange and Los Angeles Counties. Experts have considered the species to be on the decline, and the variety in southern Orange County and San Diego County is listed as a Species of Special Concern by the California Department of Fish and Game. Cactus wrens are year-round residents in patches of cactus scrub habitat, which have decreased over time due to removal from development as well as from fuel modification activities, frequent wildfires, and competition with non-native plants.

Based on the 2009 survey, the western Puente Hills supports at least 23 occupied cactus wren territories (meaning that a pair of birds was observed); most of these (16) were located in the Sycamore Canyon and Hellman Park areas. Based on a Los Angeles County estimate of 170-200 pairs, the western Puente Hills supports 10 to 15% of the cactus wrens in the County. Thankfully, many of these territories are located on Preserved land, either on the Puente Hills Preserve (owned or managed by the Habitat Authority), or on other preserved lands such as Schabarum Park. Unfortunately, some are located on privately-owned lands, and therefore may not be protected against future disturbance and habitat removal.

So, there appears to be some good news since the September 2007 blog posting. Several sites that were noted as unoccupied appear to now be occupied, such as above Hellman Park and in Schabarum Park. There is also hope that other territories are out there that have yet to be found, like the new one I stumbled upon just this morning in the Worsham Canyon area! But we’ll have to keep monitoring these territories to see if they persist or decline over time, and keep an eye on those territories on privately-owned lands, to see what the future holds for the cactus wren in the western Puente Hills.

Rattlesnake Revue

2009-08-07T09:21:00.000-07:00

Nature can sure put on some amazing, jaw-dropping shows! Last week was a case in point, as two rattlesnakes along the Powder Canyon trail put on a dazzling performance. One of the Habitat Authority's dedicated volunteer Docents, Terry Tuttle, took some incredible pictures of the over 20 minute display by two rattlesnakes in the middle of the trail. It is unclear whether these two snakes were a male and female involved in a mating ritual, or whether they were two males involved in a wrestling match for dominance over the rights to mate with a nearby female. I believe the latter is more likely, as it appears that the snakes were trying to rear up as tall as possible, which has been described as one way that males compete with each other during this type of dominance dispute. However, either scenario is possible, since rattlesnakes are known to mate in the spring as well as fall. Words cannot adequately describe the event, so I'll let the pictures below do all of the talking. Enjoy!

Nature's Garden

2009-07-30T14:20:00.000-07:00

As we approach late summer, you are likely noticing the bounty of fruits that are becoming plentiful on the plants in the Hills. Just like in many home gardens, late summer and fall is the peak of productivity for many of our fruits and vegetables, including tomatoes, many berries and squashes. Some of our native plants are closely related to the cultivated species in our gardens, but are often inedible or poisonous for humans.

One example, which is very evident during this time of year, is coyote gourd. It is also known by many other common names, including coyote melon, Calabazilla, stinking gourd, Buffalo gourd, Missouri gourd, and fetid wild pumpkin. You may have noticed a “new” patch of large, grayish-green leaves growing on the ground in a grassy or shrubby area on hikes in the hills over the past few months. This is actually the coyote gourd, but it is not new – it has been dormant over the winter and spring, with its large underground root storing lots of starch as nutrients for when the vines and leaves emerge in the summer.

The scientific name of coyote gourd is Curcurbita foetidissima, which is latin for “gourd” and “evil smelling”, because the leaves smell bad. This smell is thought to be the reason why it is called coyote gourd, because supposedly a Native American story says that that coyotes urinated on the plant to make it smell bad, leaving the fruits all for themselves to eat. Apparently Native Americans would eat the seeds of coyote gourd, like many eat pumpkin seeds today. And this similarity is not coincidence, because many pumpkins, as well as many squashes found in the grocery store (zucchini, acorn squash, yellow summer squash, and spaghetti squash) are closely related to coyote gourd. They are all from the species Curcurbita pepo. When you look at the zucchini-like yellow-orange flower of the coyote gourd, its vine and leaf structure, and its fruit (the inside even smells just like a pumpkin!), it becomes more obvious that they are all related.

Another plant related to coyote gourd that is found in our Hills, as they are both in the Curcurbitaceae (gourd) family, is wild cucumber – this plant flowered and produced fruit in the spring. However, wild cucumber seeds are not edible and are actually considered to be poisonous. But apparently both wild cucumber and coyote gourd were used for medicinal purposes by Native Americans.

Keep your eyes peeled later this summer and fall, when the leaves begin to wither, leaving behind the mature, orange-colored fruits on the ground. When the fruits dries out the seeds remain inside, making them into natural rattles - that is, if they aren’t all eaten by the animals first!

Meat “bees”

2009-07-17T17:14:00.000-07:00

While hiking the Hellman Park Trail the other day I noticed this small deer mouse (Peromyscus sp.) lying in the middle of the trail. Upon closer inspection I noticed two “meat bees” on the mouse, ripping off tiny pieces of flesh from a wound, which was likely the original source of the mouse’s death (possibly a hawk meal that slipped away?). I have “meat bees” in quotes because they are not, in fact, bees at all – rather, they are yellow jacket wasps (Vespula spp.). They are the types of wasps that have a habit of ruining a picnic or bar-be-que by attacking food persistently. These are not the same as the paper wasps (Polistes spp.) that build large hives under the eaves of houses – rather, yellow jacket wasps generally build their large hives underground such as in rodent burrows. In southern California, there are several species of yellow jacket wasps, including the native western yellow jacket (Vespula pensylvanica), shown in this photo feeding on the deer mouse. The western yellow jacket predominantly nests in abandoned burrows in hilly, natural areas, such as the Puente Hills. A similar non-native species, the German yellow jacket (V. germanica) tends to occur in more urbanized areas, preferring to build its nest off of the ground using cavities in trees or walls. The German yellow jacket became established in the northeastern U.S. in the 1970’s and reached southern California in 1991. Although yellow jackets can cause irritation at a picnic by occasionally biting or stinging, they also provide an extremely beneficial service by eliminating large numbers of other pest insects through predation. Since they are attracted to food, the best way to avoid conflicts with yellow jackets is to remove such attractants. However, if a nest is causing a true safety issue, using lure or water traps or removal of the nest by a certified professional is preferable to using pesticides, which can harm other beneficial insects.

“Butterflies” in the Hills

2009-06-02T14:54:00.001-07:00

I bet you’re thinking I’m going to be talking about the butterflies fluttering to and from the wildflowers in the Hills this time of year. But in fact, I’m referring to some of the wildflowers themselves – mariposa lilies! Mariposa means “butterfly” in Spanish, and as you can see by these photos they are as beautiful and delicate as butterflies. One of these lilies, Plummer’s mariposa lily (Calochortus plummerae) is in full bloom now in the Hills.

Plummer’s mariposa lily is a rather large lily (about 2 inches in diameter), and is generally brightly colored pink or purple with lots of yellow (or sometimes purple) hairs on the inside of the petals. It is considered to be rare by the California Native Plant Society (List 1B.2). During previous surveys throughout the Preserve several years ago as part of the Resource Management Plan, botanists located over 500 individuals scattered in numerous pockets from Hacienda Heights through Turnbull Canyon and in Powder Canyon. These lilies occur mostly on rocky or gravelly soils, often along road or trail cuts where the soil has been exposed and there is less competition from other plants and grasses. It is known from Ventura, Los Angeles, Orange, Riverside, and San Bernardino Counties.

Another rare lily called intermediate mariposa lily (Calochortus weedii var. intermedius) has also been found in the Hills, and it is also in full bloom right now. It likes to grow in similarly rocky soils as Plummer’s mariposa lily, and can have similarly colored petals and hairs. Interestingly, these two mariposa lilies are believed to be hybridizing in our Hills, such that the flowers often share characteristics of both species. This sometimes makes them difficult to tell apart, but doesn’t make them any less beautiful or rare. Get out there now and see if you can find them before it gets too hot!

Happy Mother’s Day – to all Mothers!

2009-05-08T14:32:00.001-07:00

As we all spend this Sunday paying tribute to our mothers, it is also a good time to appreciate all of the wild mothers that help to raise the next generation of reptiles, birds, mammals, and other wildlife in the hills. Like human mothers, they have to deal with a lot of challenges when raising their young before they eventually leave home and disperse to find their own place in the world. These challenges can be especially daunting when living next to our human urban and suburban environments.

Take mule deer for example. They are basically single mothers, as the males generally become solitary after mating. After an approximately 6 1/2 month gestation period, female mule deer (or does) give birth to one or two young fawns (younger does generally only have one, while older does tend to have twins). Although these young fawns are born ready to walk, their primary strategy for surviving is to hide – they lack a detectable odor and have spots to help them remain camouflaged while mom is away. So, mule deer moms have the challenge of finding a safe place for their young while they leave periodically to find food, so that they can have enough sustenance to lactate. Another challenge comes after about five weeks, when the fawns are weaned and they need to forage for food with mom. Not only are they vulnerable to attacks from predators at this time, such as mountain lions and coyotes, but they are highly vulnerable to attacks by humans…in their cars. Since mom now has another mouth or two to help feed, she must lead her young to many places to find more food – in urban areas, this means having to cross roads. Unfortunately, deer crossing signs are not enough to prevent collisions between vehicles and deer, although providing safe passages such as the wildlife underpass at Harbor Boulevard to help, and deer have been frequently documented using this underpass. Another challenge moms have is keeping their kids away from "junk food", just like human moms. Unfenced vegetable gardens or ripe or rotten fruit fallen from fruit trees can attract mule deer, which can become habituated to this unnatural food source and makes them easy targets for predators.

All moms deserve our thanks for teaching us the tools to survive in the world, and moms with wings, scales, or fur are no exception. So, thanks moms, and Happy Mother’s Day!

CHICKS!!!

2009-04-28T11:08:00.000-07:00

The result of all of that “love in the air” (see blog posting from February 25, 2009) is chicks which have hatched and are growing fast! I was able to catch a glimpse of these approximately 3-week old red-tailed hawk chicks in their nest on April 22. This same nest produced two chicks in 2006, likely from the same pair of hawks that are there now, as they can use the same nest for several years.

When I arrived, the mother was sitting on the nest, but after a while she flew off. A few moments later, two fuzzy white heads popped up! Then, they started pecking at each other, fighting like typical siblings. This photo is of the chicks in mid-fight. The mother was likely going off to hunt or retrieving prey from the father – either way, she will bring the prey (such as rodents, small mammals, even snakes) back to the nest and rip off small pieces to feed to the chicks. They will likely begin to leave the nest in about one month, after which they will continue to improve their flying and hunting skills by learning from their parents. At about 10 weeks old they should be completely independent from their parents. Check back soon, as we may be having a raptor expert come out and “band” the chicks (place small metal bracelets around their legs) so that their dispersal can be tracked over time as part of a regional study on raptor movements. Stay tuned!

An Endangered Visitor

2009-04-24T13:06:00.000-07:00

While many people have heard of our resident threatened species, the coastal California gnatcatcher, we have an endangered species that is a seasonal visitor as well – the least bell’s vireo. The least bell's vireo is migratory, so it spends the winter in Baja Mexico, but comes up north into coastal southern California to breed in the spring and summer. It has been reported as breeding in the past at the nearby Whittier Narrows.

Larry Schmahl of the Whittier Audubon Chapter reported hearing one singing in Sycamore Canyon near the trailhead on April 9, 2009; I went out and also heard and saw an individual (possibly two!) on April 16th, and I heard and saw one again just this morning. The habitat in this location is perfect for the least bell’s vireo, as they prefer dense willow riparian habitat, including associated plants such as mulefat; however, they need some structural complexity in the habitat (i.e. multiple layers), so they often nest in early successional (newer) habitats including recently restored areas. Since the riparian habitat at the Sycamore Canyon trailhead was restored within the past few years, the vireo may stick around and nest this year. Although a single least bell’s vireo was observed at this location in 2005, it did not stay to breed; however, the site may now have developed the level of habitat structure that it needs to breed – we’ll be keeping an eye, or rather an ear, out throughout the rest of the spring and summer. If the vireo continues to be seen or heard through June or July it is likely nesting in the area, and will remain until it migrates back down to Baja in August or September.

Although the least bell’s vireo has experienced population increases recently, it is still subject to threats such as habitat loss from the removal of riparian vegetation, as well as from nest parasitism from brown-headed cowbirds. These cowbirds are known to lay their own eggs in the nests of other species, including the least bell’s vireo, which result in much larger and earlier-hatching chicks that compete with the vireo chicks for food – cowbird chicks can even toss vireo eggs out of the nest before they hatch! We’ll be keeping an eye out for them as well.

Photo credits: Upper - U.S.G.S ; Lower - USFWS, Photo by Po-Hon Liu.

The snake days of spring

2009-04-15T10:14:00.000-07:00

OK – I know I already talked a little about snakes in my last blog, but given the frequency of snake observations over the last few weeks I think they deserve further attention. In fact, just yesterday I saw 3 different snakes in the Preserve in less than 3 hours! Snakes are now emerging from their winter hibernation sites and can often be found basking in the sun, stretched out in open areas. They are especially common laying across roads and trails where they can absorb the maximum amount of sun and heat from the asphalt or dirt; so keep your eyes peeled on the trail ahead – the “stick” you think you are seeing might actually be a snake! They are best spotted in the morning when they are trying to warm up for the day, since they usually retreat to vegetation or sheltered areas during the peak heat of the day in the afternoon.

I observed this young Southern Pacific rattlesnake (only about 1.5 feet) in the middle of the asphalt road in the core habitat area. Because I was driving along the road and did not want to crush it, I nudged it with a stick to make it move – it rattled a bit at me, annoyed that I was making it leave the warmth of the road, and then it reluctantly slithered off into the brush. Although this young rattler was old enough to have actual “rattles” at the end of its tail, very young rattlers only have a single “button” and cannot yet make the rattling sound. Notice the stripe or mask along its eyes and the striped skin pattern near the end of its tail, as opposed to the diamond or square patterning on the rest of its body. Rattlesnakes find their prey using heat-sensing pits on the sides of their head. Also, these snakes bear live young in the late summer, as opposed to many other snakes which lay eggs.

I observed this large San Diego gopher snake sunning itself on the road/trail right near the Arroyo Pescadero amphitheater. These snakes are very commonly observed and are not venomous, but they can sometimes inflate their head and shake the end of their tail to imitate a rattlesnake when they are threatened. They kill their prey by constricting them – coiling their body around the animal and squeezing it. The patterning on gopher snakes is highly variable, but they are generally the largest and longest of the snakes you will commonly see on the trail.

This California striped racer was seen near the Colima Road tunnel along the Arroyo San Miguel trail – I saw it chasing a small rodent across the road. This snake often holds its upper body off the ground (as shown in the photo) to help them to see and find prey with their highly acute eyesight. These snakes are also not venomous. Notice the long slender black body with the yellow stripes along its entire length – these stripes are on both sides of the body.

Although it is sometimes frightening to stumble upon a snake while hiking, it is important to respect their place in our ecosystem, as they help to keep rodent populations under control. Their beauty and diversity is one of the many things to appreciate and enjoy in the hills!

The delights and dangers of Spring

2009-03-27T16:43:00.000-07:00

The first day of spring was last week, and the wildflowers are putting on a great show in the hills. Although the most commonly noticed wildflowers are mustard (yellow) and radish (pink, purple and/or white), which are non-native invasive plants that cover large areas, many of our native plants are also in full bloom. Wild cucumber has clusters of small, star-like white flowers along its creeping vines, and morning glory and field bindweed are also vines but with white funnel-shaped flowers.

Some of our native coastal sage scrub species in bloom right now are California bush sunflower with its lush display of large, yellow daisy-like flowers, and purple sage with its small purple flowers in pom-pom clusters; the Arroyo Pescadero trailhead off

of Colima Boulevard is a great place to see these flowers.

Smaller wildflowers are also in full bloom, especially in areas disturbed by fires (such as upper Turnbull Canyon) or recent Habitat Authority restoration activities (such as along Harbor Boulevard near the wildlife underpass). These include our state flower, the California poppy, purple lupines including the small miniature lupine and the larger Arroyo lupine, and other small purple phacelia wildflowers, including wild Canterbury bells, common phacelia and Parry’s phacelia.

Also, with the weather warming up, rattlesnakes are coming out of their winter hibernation dens. Since they are cold blooded reptiles, they like to be out when it is warm and sunny, and so can be active during all parts of the day in the Springtime. During the summer, they can’t handle the intense heat of midday, so they are most active in the evening, nighttime, and early morning. They can be easy to spot when they are basking in the sun in the middle of a road or trail or on a pile of rocks, but they are also known to seek refuge in crevices and shady spots especially during peak heat. Their coloration allows them to blend in well with surrounding vegetation and dappled shade. Therefore, it’s always best to stay on an established trail, stay alert, and hike with a friend if possible. Never reach down into a hole or crevice or into underbrush where you can’t see, and always step on top of rocks or logs when you have to cross over them (don’t step over them if you can’t see what’s on the other side). Just remember, rattlesnakes only attack when they feel threatened, and don’t attack randomly. And also remember that they, like all of the native plants and wildlife in our hills, serve an important ecosystem function – they help to control resident rodent populations. If you are bitten by a rattlesnake, remain calm, try to keep the bite below the heart, do not overexert yourself, and get to a hospital immediately.

Poison oak - the shapeshifter

2009-03-06T15:09:00.000-08:00

Poison oak seems like one of the hardest plants to identify, especially to those who are not botanically-inclined. But it seems like it is the one plant everyone on trails wants to be able to identify so they can avoid its agonizingly itchy effect on the skin.

But why is poison oak so hard to identify? One main reason is that, although it is a perennial vine, it is deciduous - therefore, its leaves turn colors (generally red) in the fall and then drop off in the winter. This also means that, in the winter, it just looks like a bunch of dead branches until you accidentally brush up onto one or, heaven forbid, snap one with your hands! See photo above.

This also means that in the spring, when the new leaves emerge (for many that is right now), they are very small and it is difficult to discern the typical "leaves of 3, let it be" leaf arrangement. The young leaves are also generally a reddish color, as opposed to the deep green of the mature leaves. See photo to the right.

However, even the mature leaves can look different depending on their location. Leaves that are in full sunlight are often smaller and glossy with toxic oils, while leaves in full shade are often big and sometimes lack that glossy shine. See photo to the left - this plant is in partial sun.

So, if all else fails, and you can't remember the phrase "leaves of 3, let it be" then fall back on the phrase "when in doubt, do without" and avoid it!

If you would like to learn more interesting facts about poison oak (for example, that it is related to pistachios!) please read our previous blog from July 2, 2008 in the Archives.

Love is in the air – literally!

2009-02-25T16:29:00.000-08:00

There is a public display of affection everywhere these days, even over our heads. Spring is just around the corner and the hawks in our area (such as red-tailed hawks, red-shouldered hawks, Cooper’s hawks) are letting us know through their aerial courtship displays in the hills. Many of you undoubtedly see hawks flying overhead during the daytime, sometimes in pairs or small groups. This is especially common in the late morning or early afternoon, when hawks and turkey vultures take advantage of “thermals” which result when the air heats up and rises, helping to lift these large birds high up into the air. However, right now you may see them not only flying together, but diving toward each other or trying to land on top of each other while in the air. In fact, red-tailed hawks, the most common hawk in our area, have been reported to actually lock their talons (claws) together mid-air and plummet toward the ground together. These acrobatics are the hawks’ mating rituals or courtship, and it indicates that they have already staked out a suitable nest site, started building a nest or repairing an old one, and will be laying eggs soon. Many hawks mate for life and often return to a nest they used the previous season. So, keep your eyes peeled in the skies for some “PDA” – public display of affection – and you might be in for a great show!

Photo credit: Tom Clifton

Coexisting With Wildlife

2008-08-05T15:46:00.000-07:00

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 (http://www.habitatauthority.org/) 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.