Chick Flicks

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

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

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

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

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!