A Tale of Two Tunnels

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"

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

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

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

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

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”

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.