Thursday, January 15, 2015

Subtle Impacts of Drought & Climate Change in Southern California

It's 66˚F outside at 2:30 pm on a January day. The sky is clear, the day is beautiful. Our mid-winter in southern California is mild and lovely.

Unfortunately, people have difficulty seeing incremental local climate changes if those changes do not have a concrete negative impact on themselves. In addition, most people who have relocated to Los Angeles from places with snowy or harsh winters do not even notice our subtle seasons.

toyon berries, 1/15/15
Today however I came face-to-face with an impact from drought and climate change that is having a direct impact on my neighbors and their migratory relatives. The toyon or California holly should be filled with red berries (what toyon should look like in December/January). Because of the drought the two bushes in the front of the house did not fruit at all this year and the toyon at the top of the hill has fruit that look like this...small and unripe.

The northern mockingbird that only occasionally visits our yard was here this morning hunting for fruit, it found none. The hermit thrush who visits annually was also searching for toyon fruit. Unlike the mockingbird, it has come here from the north to spend the winter in a location that should offer winter fruit. Both are having to supplement their diets with more insects. 

High in the eucalyptus tree the mewing cries of a small flock of cedar waxwings caught my attention. Twenty-seven of these fruit-eating birds sat pondering their next move. They too were here looking for the toyon berries that they expected to find on our hillside. When they found nothing, they went hungry. They regathered and flew on.

For these birds, drought means smaller, less nutritious food. But subtle changes in our climate are also altering when the fruit ripens. Imagine driving across the Mojave desert with the plan to stop at that favorite restaurant only to find that the town is closed up and the next place to find food is 100s of miles away.

Subtle changes in our local climate are impacting wild species that are tied to the fruiting or flowering of specific plants. We need to increase our awareness. 

Friday, January 09, 2015

Encountering a Bull Elk

Why create habitat in your yard? Because when you interact with other living things you have a better understanding of yourself. Sounds a bit heavy-handed, but I believe it. 

A backyard with habitat attracts native species. Today a red-tailed hawk watched me trying to apprehend a pocket gopher. Check out video of our resident Bewick's wrens, valley carpenter bees, lizards, grasshoppers and red jumping spider.

this younger male is small by comparison and still in velvet
Living in a metropolitan area, my interactions with large animals come when I'm off hiking or traveling. This summer I had an amazing encounter with a bull Roosevelt elk (Cervus elaphus roosevelti). He was right off a heavily trafficked trail in Redwoods National Park, but few people noticed him. The Roosevelt elk is the largest subspecies of elk surviving in North America and this male was huge, the size of a large horse. He stood 5 foot to the shoulder, with a long neck, and antlers that reached 3-4 feet up from his head.

Bull Roosevelt elk average a 16-year life span in the wild. The older the male the larger and more branched his antlers. Elk antlers are a renewable resource; they drop off after the breeding season and are grown anew the following year.

The older male shown here is just entering the rut, or breeding season. While the antlers are growing they are covered with a thin layer of tissue and are vascular, blood flows through the bony growth. As the breeding season approaches in the fall, antlers stop growing. Blood stops flowing through the antler and thin skin layer. The tissue covering dries up and the bull rubs his antlers against bushes and other vegetation to remove the velvety covering. Here you can see that this male has been removing velvet that still had some vascular circulation; his antlers appear bloody. 

With the beginning of the rut, male elk are filled with testosterone. Breeding and competing for females take priority over any other activity, even eating. Few males remain the dominant or top breeding male for more than a season. A top male will frequently be so worn out by the end of the rut that he does not have the energy reserves to survive the winter.

two female elk with their calves at twilight
The Roosevelt elk is found only along the northwest coast from northern California, to Oregon and Washington, and on two Alaskan islands where they were introduced. The subspecies was named for President Theodore Roosevelt who created Olympic National Park in Washington state as a preserve for the 20 remaining members of this elk subspecies in the early 1900s. Today over 7,000 individual Roosevelt elk can be found across their range. They are another example of successful conservation, including well-managed hunting. Channel Island Fox.

This large member of the deer family plays an important role in clearing the forest understory. They help keep forests healthy by creating open space for other animals and encouraging the growth of young plants. Healthy elk populations, however, need predators. Let's keep our fingers crossed for the gray wolves making their way back into California and the mountain lions trying to maintain healthy numbers. 

In the mean time, make 2015 the year you make your backyard a habitat for native plants and wildlife.