Show and Tell

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!!!

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?

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

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

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).