Saturday, January 29, 2011

Winter Blooming Flowers

While much of the rest of the country is white with snow, Californians can still delight in a variety of winter-blooming flowers.

In Zone 1, along the walkway and protected by the front steps, winter-blooming bergenia (Bergenia crassifolia) sends up flower stalks in January. This isn't a native plant. However this small patch was planted here when we moved into the house years ago. A native of the Himalayas, they thrive in poor soil and tolerate drought in a shady location. Under the steps seems the perfect location for them, and occasionally, native slender salamanders can be found in the leaf litter that builds up beneath the plants.

Zone Map

Friday, January 21, 2011

Mapping Hummingbird Territory

Before I can gather new biodiversity data, I have to format my data collection and tabulation. That means creating a species data base, determining the data to be collected and finalizing the areas where data will be collected. I've already updated my Zone Map.

But this time around I've decided to map out the territories of my resident hummingbirds. I plan to update these territory maps monthly. As we start off this January, one of the males, FIK, has expanded his territory.  I have a special connection to FIK a male Allen's hummingbird. He was hatched in 2008 in the same plum tree that is the center of his territory. When he was a chick, a predator attacked the nest. His sibling did not survive, but FIK fell 20 ft. to semi-safety in the foliage below the tree. My dog, Inali, found him and with a little bit of ingenuity, she and I saved this tiny fellow. The whole story.

In 2009, FIK bred with a number of females and we had over a dozen chicks. Only one of the females in the yard, DR, has been here as long as FIK. 
Last year FIK was the dominant male and he spent so much energy breeding, by the end of summer 2010, he was spent. His son, BIF (blue), almost pushed him out of his territory.

Now with the warm weather, the male Allen's hummingbirds are beginning to perform their breeding displays for the females. FIK is back up to fighting strength and he has reclaimed his former territory. His territory (green) is once again the largest. At the front of the house, he has the greatest visibility to visiting females.

DR is the oldest female and she has the largest territory of the girls (red), however, she does not have the prime territory. There is no feeder in her territory. However, she does have nectar-bearing and insect-attracting plants, and two native Catalina cherry trees where she has nested successfully for two years. 2010 nest.

A daughter of the long dominant "A" family of females, A-Spot, holds the prime female location with a feeder (orange). A young female, F, who's first attempts at nesting failed last year, maintains a small territory (yellow).

With three adult male Allen's hummingbirds, all in their prime, we could be in for territory challenges. Canyon (purple) also a chick from 2009 and probably a son of FIK, maintains a small territory at the back of the yard. And there is a newcomer, an immature Anna's male that has established his territory at the back of the yard (lime) next to Canyon.

More males, most likely will mean fewer females will nest here. But there is a large area of hillside territory with nesting locations that is unclaimed. Will a new female move in? It should be a fascinating spring.

Friday, January 14, 2011

Mapping the Backyard Biodiversity Project

The first step in documenting the biodiversity in our backyard ecosystem is dividing the landscape into Zones.

I have mapped the yards (front and back) into 18 Zones with an additional Garage Zone and House Zone.

These Zones are determined using physical separations (walls, fences, concrete walkways, gravel paths) and by clumping the natural microhabitats. For example, Zone 1 includes a planter against the house and a concrete walkway with stairs. This area is heavily used by people going in and out of the house. This activity has an effect on the plants and animals willing to live there. I have examined Zone 1 in detail before. Zone 1, 2007

Zone 2 has changed dramatically since I first documented the species living there in 2001, 2004 and 2007. This Zone is a raised planter in front of the house stretching from the sidewalk to the walkway and extending to the western corner of the house. It is landscaped and receives moderate sun in the summer. It was my observation of alien plants attracting alien pest species and creating a dead zone for native animal species that first inspired me to remove the African daisies in this planter and replace them with native plants. It will be interesting to see how the biodiversity in this area compares with ten years ago. Zone 2, 2007

Zone 17 is the lower end of the driveway at the side of the house and a small planter that typically only receives rain water. But this area has offered surprises in the past. Zone 17, 2007

Creating Zones provides manageable areas of observation and also allows comparison between areas that are similar or dissimilar in terrain, physical attributes and water availability. Off to a good start.

Monday, January 10, 2011

New Year's Cleaning - Bird Houses

A pair of oak titmouses are checking out the bird houses for a spring nesting site. I've been trying for 5 years to get them to nest in our yard so this year I'm cleaning out the bird houses early. Last year a number of bird species nested unusually early in the yard because of changing climate patterns. (Climate Change in California).
The Bewick's wrens love this rope bird house, but they won't reuse it if I don't clean it out. They fill it to the brim with nesting material to make it cozy. Unfortunately, they won't come back unless all of the previous year's debris is removed.

Cleaning out the titmouse bird house I discovered a western bumble bee nest

If the changing climate alters when the birds begin looking for nest sites, I have to alter when I prepare the bird houses. 

Cavity nesting birds like the titmouses and wrens can have a difficult time finding appropriate nesting sites in cities. Providing suitable housing opportunities for them helps to maintain their populations. Many cavity nesters are insect predators, eating many of the bugs we consider to be pests. Offering them an appropriate bird house invites them to be your neighbors and gives you the opportunity to watch them raise their families.

Friday, January 07, 2011

Backyard Biodiversity Project 2011

Around the world biologists are gathering information on animal and plant biodiversity in wild places, but I can’t help but wonder how much we are missing in our own backyards. We raise money to save distant rain forests and try to change the daily lives of people in far away lands but what actions do we take to positively impact the ecosystems where we live?

I’ve seen amazing transformations in small areas of my yard by removing introduced exotic plants and restoring native plants to the landscape. Native Plants. The Mexican mountain marigold (pictured) provides food for pollen-eating insects even in the winter. I keep trying small gestures to provide more opportunities for native species. Bee Box.

Just in the last two months we’ve seen an amazing biodiversity in spider species without really trying: red jumping spider, trapdoor spider, green lynx spider. In the past I’ve found small areas around the house are home to numerous spider species. Here Be Spiders.

This afternoon I checked on the green lynx spider egg casing. It has survived the December rains, but for the past week the mother protecting the egg sac has been gone. Did she perish in the cold weather? Temperatures have been in the mid-30s to 40s at night. This spider species only lives about a year and adults typically do not survive winter weather.

According to several university websites, females lay their eggs in an egg sac in autumn. We saw this egg sac in the second week of November. The female guards the eggs for 2 weeks until they hatch. The mother opens the tough webbing of the egg sac to release the spiderlings and she provides protection and sometimes food for the next 2-3 weeks. See University of CA, Irvine photos. When the young spiders disperse, her job is done. The youngsters will overwinter, but their mother will die.

Last year we had an unusually warm December and early January. We discovered our first green lynx spider in the yard with her egg sac on the scented geraniums in the vegetable garden. By February, drenching winter rains destroyed the egg sac.

This year it has been almost 2 months since I first discovered the green lynx spider and her egg sac, but again the spiderlings have not hatched. I don’t know if the female realized the eggs were not going to hatch and abandoned them or if she died. Typically, a female will guard her egg sacs until she perishes from starvation. Last week the female was looking very thin.

What happened to these eggs? I decided to open up the egg sac and see whether or not the eggs were viable. Looking through my microscope I could see that about a third of the eggs seemed infertile, they were dark and showed no development. Another third or more appeared plump and ranging from an orangy-yellow to pale white. A few appeared to have been forming into spiderlings, the shape of the carapace was somewhat apparent. But these embryos on their way to becoming spiderlings, seemed slightly dried-up. 

Considering we had nearly a week of rain in mid-December, this seems odd. But something with the weather was not right for these eggs to develop. For a second year in a row beautiful green lynx spiders have failed to reproduce in the garden.

Are there more green lynx spiders in the yard and I’ve just missed them? Are their other spiders failing to reproduce? This leads me back to the Backyard Biodiversity Project.

Are there creatures to waiting to be discovered right here in a backyard in Los Angeles, California? I think so. I plan to take a scientific look at the creatures and plants living in our small yard in one of the largest cities in the world. I’ve started the Backyard Biodiversity Project before only to be interrupted by acceptance to graduate school. Now I’m plunging into the year with the intention of spending the next 12 months on this project.

What’s in your backyard?