Tuesday, December 22, 2009

'Tis the season for mistletoe and "holly"

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!

Friday, December 18, 2009

Recent wildlife sightings

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).

Monday, September 28, 2009

Cactus wren update - reasons for hope and caution

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.

Friday, August 7, 2009

Rattlesnake Revue

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!

Thursday, July 30, 2009

Nature's Garden

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!

Friday, July 17, 2009

Meat “bees”

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.

Tuesday, June 2, 2009

“Butterflies” in the Hills

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!

Friday, May 8, 2009

Happy Mother’s Day – to all Mothers!

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!

Tuesday, April 28, 2009


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!

Friday, April 24, 2009

An Endangered Visitor

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.

Wednesday, April 15, 2009

The snake days of spring

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!

Friday, March 27, 2009

The delights and dangers of Spring

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.

Friday, March 6, 2009

Poison oak - the shapeshifter

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.

Wednesday, February 25, 2009

Love is in the air – literally!

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