Shaking it Up with Rattlesnakes - by Bo Gould (intern)

The Puente Hills Preserve is home to an intricate array of native plants, mammals, birds, insects, and reptiles, among others, all of whom play a vital role in supporting the health of the ecosystem. While visiting the Preserve’s beautiful natural scenery and observing its abundant wildlife, there is a group of southern Californian natives that can be particularly exciting to meet; the rattlesnakes. If you have visited the hills recently, you may have come across signs at a trailhead warning about the dangers of this reptile. However, there are many aspects of this snake that make it a special and integral part of the Puente Hills wildlife community.


Western Rattlesnake

Red Diamond Rattlesnake

In all, there are 32 known species of rattlesnakes; 7 of which can be found in California. The Puente Hills are home to two of such species; the western rattlesnake (Crotalus viridis) and the red diamond rattlesnake (Crotalus ruber). Both species can often be observed slithering among trailside grasses, stretched out on a trail or sunbathing on rock outcrops, and can grow to be over 3 feet long. The western rattlesnake is distinguished by tan and dark-brown blotches, a triangular head with pit heat-sensors on both sides, and two internasals at the tip of its head. The red diamond rattlesnake, as its name suggests, displays reddish to tan diamond-shaped scales with black-and-white bands along its tail. The coloration of rattlesnakes helps them to effectively camouflage themselves in the environment and stay well-hidden from predators.

When these snakes shed their skin, each shedding produces a new rattle at the end of their tails. These rattles are definitive characteristics of the snake and can be heard as a warning signal to potential threats or predators. Rattlesnakes will typically give a short rattle as a warning, which will grow to a steady loud rattle if the snake feels threatened. If you hear a rattlesnake, do not move until you locate the precise location of the snake, back away slowly, and keep a safe distance. Rattlesnakes rarely strike if they are unprovoked.  Never attempt to pick up a rattlesnake!

Like all pit vipers, rattlesnakes are equipped with an exceptional set of sensory organs that help them locate prey. These include pits at the tip of their nose to sense thermal radiation from warm-blooded animals, eyes adapted to nocturnal use, and a keen sense of smell from both nostrils and sensory tissues on their tongues.

Once a prey animal is located, rattlesnakes use their quick striking ability and fangs to inject powerful hemotoxic venoms. The venom travels through the blood of the prey, causing intense swelling, pain, and tissue damage. The main prey of Puente Hills rattlers are rabbits, squirrels, rats, birds, lizards, and some insects. Though rattlesnakes are effective predators themselves, they are also heavily preyed upon by hawks, crows, foxes, raccoons, and coyotes. Thus, the ecological significance of rattlesnakes is large as they help to regulate rodent populations and provide food for other native Puente Hills species.  

Although rattlesnakes are dangerous, the likelihood of being bit is very low. If you see a snake, stay calm and slowly move away. Remember to stay on designated trails within the Preserve and scan the trail ahead. If a snake is directly in the path, keeping a safe distance and stomping your feet is usually enough to coax the rattlesnake to sun in a new spot. In the case of a snakebite, do not panic! Remove all rings, watches, and anything else in the area of the wound that may restrict blood flow. Remain calm and call 911 immediately. If treated promptly, rattlesnake bites are almost never fatal. You are more likely to be struck by lightning than to be bit by a rattlesnake.

So when on the trails, keep an eye out for this important part of the Puente Hills ecosystem and watch your step!

Living With Coyotes

HELP KEEP COYOTES WILD                

Coyotes help the environment.  They help keep populations of rodents and other small mammals under control. They also feed on raccoons, birds, insects, fruits/vegetables, human garbage, outdoor pet food and small pets left unprotected (even in your backyard). 

Attacks on humans are very rare.  When coyotes become accustomed to humans they can lose their shyness and become more demanding.  An average adult coyote is about 35 pounds and will be intimidated by people. While they may stop and observe, they will eventually run.  Coyotes can be seen any time of day but are typically most active at night; some have even become year round residents of urban areas.  They also become very active and visible during the pup-rearing season (May – July).

Associating urban areas with food.  To coexist, it is important that coyotes do not associate urban areas with food.  Coyotes are naturally fearful of humans, however they readily lose that fear when people intentionally (or unintentionally) provide food/water or shelter for them, or otherwise do not try to deter them from visiting. Eliminating sources that attract coyotes can go a long way in addressing the situation. 

What can you do?

  · Do not feed coyotes and other wildlife.
  · Make sure outside garbage is secured and fallen fruit from trees and bird seed from bird feeders is picked up. 
  · Do not feed your pets outdoors or leave pet food and water outdoors unattended, especially at night. 
  · Do not allow pets to roam free outside (including in your backyard), especially at night; make sure to keep your dog on a leash during walks.
  · Keep your landscaping trimmed and open so that they don’t provide hiding places for coyotes or other wildlife.
  · Make sure that fencing around your yard is secure –six-foot tall and buried six inches deep is recommended to prevent digging underneath it. 

If approached by a coyote or if one is in your neighborhood:
  · "Haze” them. Stand tall, yell, wave your arms, blow a whistle or horn, bang pots or pans together, spray water or throw rocks.
  · While they may stop and observe, they will eventually run.
  · Do not run away or turn your back on them. Stand your ground and then back   slowly away while practicing hazing techniques.
  · If you feel your personal safety is immediately at risk, call 911.

Informative links and contacts:

City of Whittier:  http://www.cityofwhittier.org/depts/clerk/coyotes.asp

California Department of Fish and Wildlife: http://www.dfg.ca.gov/keepmewild/

Habitat Authority: http://www.habitatauthority.org/living-with-wildlife/

Police Department: 562-567-9200 (non-emergency)                        
 

LA County Animal Control: 562-940-6898 (dead animal pickup)           

It’s the Great Backyard Bird Count

If you’re interested in citizen-science and birding then this is the weekend for you!  Started by Cornell University and the National Audubon Society, the Great Backyard Bird Count is scheduled for February 14-17, 2014.  Citizens are being asked to collect data on wild birds and submit them online.  It can be as simple as counting birds for at least 15 minutes in your backyard for one day or participate by visiting numerous locations over the 4 days, it’s up to you. 

In 2013, there were participants in 111 countries that counted over 33 million birds! These data can assist researchers in answering questions related to how climate change can affect bird populations, timing of migrations over years, and differences in bird diversity in urban, rural and natural areas, to name a few. 

To get started, go to the following link http://gbbc.birdcount.org/get-started/ and register online.  All the information you need to participate is on their website.

I know I’ll be participating….will you?

Happy Birding!

Rodenticides....Unintended Consequences

 If it’s sold on store shelves, it must be safe…right? Not always.

In 2008, the U.S. Environmental Protection Agency (EPA) released new safety measures intended to reduce children’s exposures to rodenticides in the home and reduce risks to wildlife. These measures were to be implemented by 2011 but not all companies complied with the measures.  In response, the EPA recently took action to remove 12 rodenticide products from the market but pending litigation has stopped the ban for now. 

So what’s all the concern since rodenticides kill rodents?  Yes, rodenticides contain active ingredients that kill rodents in varying ways. However, they can also kill or seriously compromise the health of non-target wildlife, children and pets. The Red-tailed Hawk, Great-horned Owl, Bobcat, Mountain Lion, Gray Fox, Red Fox, Black Bear, and Turkey Vulture, to name a few, are species that can be negatively impacted by rodenticides.  In California, the Department of Pesticide Regulation (DPR) has determined that impacts to non-target wildlife by second-generation anticoagulant rodenticides are a statewide issue and is proposing new regulatory action (No. 13-002) to designate those rodenticides as restricted materials and limit the placement of aboveground baits.

So what are rodenticides? Rodenticides are pesticides that contain active ingredients that can be classified into three types: 1) acute toxicants (AT’s), 2) first-generation anticoagulant rodenticides (FGAR’s) and 3) second-generation anticoagulant rodenticides (SGAR’s), and they are placed indoors or outdoors in tablet, pellet and/or paraffin block form. They can even be contained in bait stations. Acute toxicants work in several ways such as impairing nerve cell action or causing cell death.  With anticoagulant rodenticides, the animals’ blood loses its clotting ability and capillaries are damaged, causing the individual to die from internal bleeding. With FGAR’s, animals must consume the rodenticide several times to accumulate a lethal amount of toxin in their body and some animals became resistant to the active ingredient(s).  Therefore, SGAR’s were developed that are more toxic and designed so that lethal concentrations are consumed in just one feeding.  However, it takes several days for the rodent to die during which time it can return to feed on the rodenticide, building up extremely high concentrations in its tissues.  If it becomes prey for predators, those high concentrations of rodenticides are passed to the predator and can be lethal or compromise the non-target animals' health.  

 Aside from direct death due to anticoagulant toxicity, wildlife exposure to anticoagulant rodenticides can weaken an animals' immune system, making it vulnerable to other diseases/infections such as mange, a disease caused by a parasitic mite. Mange causes intense itching, hair loss and eventually thickening of the skin if the host animal is not healthy enough to fight the infestation.  Eventually, the skin may tear leading to bacterial infections and death.  A study conducted in the Santa Monica Mountains (Riley et al 2007) determined that two (2) mountain lions died as a direct result of anticoagulant toxicity, 90% of dead bobcats tested positive for anticoagulants and there was a high level of association in bobcats between severe mange and anticoagulant exposure. In the Puente Hills, one bobcat tested positive for anticoagulants rodenticides, at least one other bobcat died with severe mange while a third with severe mange was captured, treated and re-released. 

Currently, numerous cities and counties are showing support for the EPA and DPR by passing resolutions opposing the sale, purchase and use of certain rat and mouse poison products that pose an unacceptable risk to children, pets and wildlife.  The Board of Directors for the Puente Hills Habitat Preservation Authority passed one such resolution in August 2013 as did the City of Whittier in July 2013.  You can have your voice be heard by submitting comments to the California DPR on their Notice of Proposed Regulatory Action No. 13-002 by October 4, 2013, before 5:00 p.m. More information can be found at: 

http://www.cdpr.ca.gov/docs/legbills/rulepkgs/13-002/notice.pdf

http://www.epa.gov/oppsrrd1/reregistration/rodenticides/finalriskdecision.htm

Stop, look, listen!

If you’ve hiked in the Puente Hills you’ve probably heard drumming on trees or noticed horizontal holes drilled into trees with sap flowing from them; all courtesy of a group of birds called sapsuckers.  Sapsuckers belong to the bird Family Picidae that includes woodpeckers.  There are about 200
species of picids worldwide, of which two species of sapsuckers, Red-breasted sapsucker (Sphyrapicus ruber) and the red-naped sapsucker (Sphyrapicus nuchalis), have been confirmed on Habitat Authority managed land. 

The Red-breasted Sapsucker is a medium sized woodpecker with a red head, nape, throat and breast, cream colored belly, white rump and white moustache stripe.  Preferring to drill sap wells in riparian species, they inhabit forest edges and woodlands.  Breeding occurs from Alaska and British Columbia south to California and wintering grounds are located throughout most of their breeding range. They are cavity nesters and drill out new nest cavities typically annually.  Their diet consists of sap, arthropods and some fruits. 

Red-naped sapsuckers differ in that they have a red head and nape, cream breast and belly.  They breed in the Rocky Mountains and winter in southern California typically along the edges of forests and woodlands, especially groves of aspen and alder.  They are also cavity nesters and their diet consists of sap, arthropods and some fruits. 

Sapsuckers use their strong bills to drill sap holes, collectively called sap wells, into living trees and eat the sap along with some insects that are attracted to, and get trapped by, the sap.  The shape and size of the sap holes differs by species and the holes drilled in these pictures were likely made by the red-breasted sapsucker.  These sap wells can also be an attractant for species like hummingbirds who eat the sap that the sapsucker keeps flowing.  Large sap wells can cause extensive damage to trees leading to tree mortality while other times trees can heal themselves and continue growing.  Not all activities of sapsuckers are problematic.  Sapsuckers usually excavate new nests every year, leaving old nesting cavities for a variety of woodland/forest species to inhabit. 

So when you’re out on the trail, keep your eyes and ears open for these wonderful birds!

 

Something is bugging our oaks...

Over the last few years, I’ve noticed that the large coast live oak trees along Turnbull Canyon Road appear to have small patches of dead leaves on them, but the trees appear to be healthy otherwise. For a while, I dismissed the dead leaves as a symptom of drought. But as I was made aware of a devastating new pest that is affecting oaks in San Diego County, called the gold-spotted oak borer, I’ve been paying a bit more attention to trees that appear distressed. Although there could be several things causing the dead leaf patches on our oaks, including other insect pests and fungi, I became concerned that these oaks could perhaps be affected by the gold-spotted oak borer. So, I examined some of them closely.

While gold-spotted oak borer attacks can cause thinning of the tree crown and die-back of twigs, none of the trees appeared to exhibit any of the classic symptoms along the trunk, such as weeping or staining, or tiny D-shaped exit holes. What I did find was at the point where the dead twigs met with the live tree branch, under the bark there was a pattern etched in the tissue spiraling around the twig, with dark powdery “frass”inside the tunnels (see photo) – I even found a tiny larva in one! This indicated that the damage could be caused by an insect called the oak twig girdler. It is similar to the gold-spotted oak borer, in that they are related – gold-spotted oak borer’s scientific name is Agrilus coxalis, and the oak twig girdler’s scientific name is Agrilus angelicus. Also, both attack the tree’s tissue just below the bark, causing the growth beyond the attack site to die. However, the gold-spotted oak borer attacks the trunks of trees, whereas the oak twig girdler only attacks the smallest twigs at the ends of branches where new growth is happening. That is why the gold-spotted oak borer is much more of a threat, because when it attacks the trunk tissue, it prevents nutrients from reaching the rest of the tree (branches and leaves).

The larva I collected is being sent to the Los Angeles County Department of Agricultural Weights and Measures for entomologists to confirm whether it is the oak twig girdler. Fortunately, the oak twig girdler is not considered to be a significant impact to tree health. But the presence of these insects may be a sign that our oaks are under some stress, as the oak twig girdler is thought to be attracted to trees weakened by drought.

**UPDATE: The Los Angeles County Entomologist confirmed that this is likely the oak twig girdler, and that it is not a cause for concern. He also mentioned that this is a native species.

Should you be afraid of bobcats?

We at the Habitat Authority have gotten several calls over the years from local residents or hikers asking this very question. It is understandable for people to be afraid of things they are not familiar with, and given the relatively reclusive and secretive nature of bobcats, most people never see bobcats.

Some people are afraid of bobcats because they associate them with mountain lions. It is true that they are both wild felines. However, bobcats are much smaller than mountain lions (about 10 times smaller), and are only about the size of a beagle or about twice the size of an average housecat. (They also look quite different, with bobcats having short “bobbed” tails and a striped or spotted body, whereas mountain lions have a very long tail and are a uniform tan color). Given their small size, they also eat smaller prey than mountain lions; bobcats generally eat rabbits or rodents, while mountain lions almost exclusively eat deer.

Although there are rare reports of mountain lion attacks on people (none in the Puente Hills area), there are almost no records of bobcat attacks on people. The few credible reports that do exist generally have to do with a rabid bobcat, which is quite unusual. No reports of rabid wildlife of any kind have been reported to the Habitat Authority.

Bobcats, like mountain lions, generally avoid people and areas inhabited by people. They tend to be found less often along trails with higher recreational activity, and they often shift their activity to occur at nighttime in areas frequented by people in an effort to avoid them. Bobcat home ranges occur much more frequently in natural habitat compared to areas within or near developed areas.

If you see a bobcat in your neighborhood, it probably means that you have a lot of natural vegetation in the area. If there are a lot of rabbits or rodents in your neighborhood gardens, that might also attract bobcats. If you want to keep bobcats or other wildlife out of your yard, consider installing fencing around your immediate use area, make sure to clean up fallen fruit or other potential food items (trash, bird seed) that might attract rodents, keep small pets indoors and/or closely supervised, and never intentionally provide food or water to wildlife.

There is no reason to fear bobcats, but bobcats have plenty of reasons to fear us. In most remaining natural areas in southern California, bobcats have to face many challenges in order to survive. One major challenge is crossing numerous busy roads safely. Another challenge is not becoming infected with diseases which could be passed on from other animals or even domestic pets, and not eating rodents that have been poisoned; rat poisons contain anticoagulants and are shown to have a possible association with a disease called mange. Another challenge is finding large enough patches of habitat that are relatively free from human disturbance in order to live and rear their young.

If you do see a bobcat, you should consider yourself very lucky! Seeing a bobcat is a good way to remind us of the wildness that is still present in our area.
(Photo credits: top - Doug Wolfe, drawing - Cougar Network, time-stamped - Puente Hills Habitat Preservation Authority)