“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!

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!

CHICKS!!!

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

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

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

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

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.