Monday, November 22, 2021

Rat Spill

I learned a new term this weekend "rat spill."

Santa Rosa Island, Channel Islands Nat'l Park

Think of an oil spill and then replace the oil with introduced black or brown rats flowing onto an island and threatening the entire natural habitat: animals and plants.

It's quite an image and appropriate for the environmental damage that can occur when these large rat species are introduced to an island ecosystem. California's Channel Islands are constantly threatened by the potential of rat spill. 

Black rats (Rattus rattus) and brown rats (Rattus norvegicus) are the number one cause of extinction for reptile and bird species on islands. These large rodents reproduce rapidly and eat everything, including eggs and hatchlings.  


Because islands are primary nesting locations for seabirds, rat spill can take out entire populations. Brown pelicans, oyster catchers, western gulls, and rare species–like ashy storm petrels and Scripp's murrelets–all nest on California's Anacapa Island. Prior to 1940, however, a rat spill introduced hungry rodents to the island with devastating impacts. Some of the bird species were headed toward extinction.

Beginning with efforts in 2001, Channel Islands National Park spent millions of dollars eradicating the rat spill. The effort was successful, but the process wouldn't be feasible on larger neighboring islands with small endemic mammals–like the island fox and island spotted skunk live.


While you might think an island fox could prey on a large rat, the fox's small size and the rat's aggressive self-protection, make this rodent a difficult catch for the diminutive island fox. Additionally, rats are a disease vector and can bring viruses, which threaten the fox's survival. 

more about island foxes

Across the Channel Islands prevention is the goal. Just like with oil, it is much more cost effective to prevent a rat spill, than to clean up the damage and hope you can restore a habitat. 

Take a virtual visit to the Channel Islands 

Tuesday, November 09, 2021

The Fight to Relist Wolves As Endangered

Today a trial begins in Ventura County seeking a court order for the Biden Administration to relist the gray wolf as an endangered species. A private individual and several conservation organizations are arguing that gray wolves once existed across North America and people have a right to see this icon animal in the wild. They argue wolves should be protected until their numbers and range have recovered from centuries of extermination.

Ironically, a single radio-collared gray wolf arrived in the northern reaches of Ventura County earlier this year. This lone male wolf has dispersed from the California/Oregon boarder where a small family of wolves have re-established territory.

Yellowstone's Hayden Valley

There is no doubt that the environment needs the return of this large predator. The return of wolves to Yellowstone National Park has had a transformative impact on the ecosystem. Wolves outside of the Park, however, have often met with persecution and slaughter.

Have wolves recovered across North America? No. Should they continue to have Endangered Species status? States with large natural populations, say 'No.' A single wolf in Southern California, surely deserves some protection. He also deserves the possibility of finding a mate, not a life of perpetual wandering to find a female that doesn't exist.

Do I want a wolf in my backyard? We have a pack of coyotes, now. They were very vocal last night. When there are eight to ten coyotes out in the darkness, our fifty pound dog can't go out into the yard alone. There have been several occasions when he has come face-to-face with them at the edge of the patio. Is he slightly bigger than the coyotes? Yes, but he is a retriever breed with rounded teeth that  give him little defense against a coyote pack. These coyotes have changed their natural behavior to try and fill the niche of wolves. They hunt in a pack, rather than in pairs.

The Endangered Species Act can't be a one size fits all protection. There needs to be a way to address species protection locally that is integrated into a national effort. Such an effort would require people coming together and that seems harder now than it did ten years ago. For every person who claims it is their constitutional right to see wolves in the wild, there is a person who will say it is their right to let their dog, cattle, sheep, etc out of an enclosure into an area safe from attack by wolves. The emotional turmoil around wolves.

Because wolves are a species across a wide and diverse range, it is time to rethink how we approach their protection and reintegration with humans. Those who love wolves can't litigate those who hate wolves to change their minds.

Tuesday, October 26, 2021

What's Happening in Wisconsin?

A new bill has been proposed in the Wisconsin Statehouse: SB-620. It would expand hunting for a range of wildlife, including sandhill cranes (Antigone canadensis).


I've seen sandhill cranes in Yellowstone National Park and Seedskadee National Wildlife Refuge in Wyoming. Notice something in common between these locations? Federally protected land. The only other place I've seen these North American cranes is flying over the Rock River at sunset in Wisconsin.

whooping crane
Baraboo, Wisconsin, is home to the International Crane Foundation, an organization that began with two young biologists determined to save the whooping crane (Grus americana) from extinction. In 1950, there were only 34 individuals in the wild. The total whooping crane population in 2021 numbers just over 800. (There were more students in my high school graduating class.) 

The International Crane Foundation has become a leader in crane conservation around the world. They not only breed these magnificent birds, but the organization mitigates conflict between people and the fifteen species of cranes around the world.

black-necked crane
Now conflict has come to their front door. Wisconsin is one of the southern-most breeding areas for sandhill cranes. Some breed as far north as Alaska and Eastern Siberia, most breed in Canada. Seen across North America, sandhill cranes migrate south as far as Texas and Mexico in the winter. More about sandhill cranes. State Bill 620 would have people believe that shooting sandhill cranes is the only way to reduce their impact on some corn crops in Wisconsin. But there are other non-lethal options that ICF has implemented in other parts of the world. ICF's statement on SB-620

This bill isn't about cranes. It isn't about science or practical ways to resolve issues between farmers and wildlife. This is about a small group of people who want to force their privilege to do whatever they want despite the costs or consequences. It's about politics, not corn or cranes.

blue cranes

Cranes need a voice. We have developed their habitat, drained their wetlands. If farmers in third world countries can find ways to share the land with cranes, surely we can too. 

Cranes mate for life. They are lucky if they raise a chick to adulthood every third year. What can seem like a large population today can be quickly decimated. Support conservation that works. Raise your voice with the International Crane Foundation.

Tuesday, October 19, 2021

Protecting the Urban Forest

Anna's hummingbird
A week ago the ironwood tree across the street burst into bloom. It was one of the few ironwood and eucalyptus trees in the neighborhood that was doing well. Most have been severely impacted by CA's continuing drought.

The blooming tree was an oasis for migrating birds - Hutton's vireo, Anna's hummingbirds, yellow-rumped warblers, Townsend's warbler, a black-throated gray warbler, and ruby-crowned kinglets. All of these species were documented in a single morning last week. The resident Allen's hummingbirds were also imbibing of the flower nectar. This single tree was providing natural food and sanctuary.

This morning the ironwood and its neighboring red gum eucalyptus are savagely reduced to skeletons. The red gum has been poorly trimmed before. Because of it, its shortened limbs have been forced to send out new growth that is unstable and tends to break off in winds. To reduce the dropped limbs the home owner made the same mistake again, repeating a cycle of mismanaged trimming that will cause this tree to regrow fragile limbs and result in shortening its life. Each chopped off limb is now open to insect and fungal invaders. It is a cycle I have witnessed throughout my neighborhood for twenty-five years.

Twenty-five years ago our neighborhood was renowned for its tree-lined streets. We were typically cooler than other neighborhoods. Today 90% of our large trees are gone and Woodland Hills frequently records the hottest temperatures in the west San Fernando Valley.


In the remnant of a single blooming branch a small Hutton's vireo sat bewildered. (circled in green)


How do we stop deforesting our urban forest? How do we teach people the value of their trees and the shade they provide? What steps can we take to plant trees that both provide habitat for native wildlife and are compatible with urban needs?

Who speaks for the urban forest?

Friday, September 24, 2021

Water - A Vital Resource for Wild Birds

This morning we awoke to this...

 

... a swirl of ash on the water dish on the ground. A bird coming south from the fires in northern and central California, stopped for a bath or at least a drink.

Especially in the dry weather we are having water is a vital resource for wildlife. On an especially hot dry day, two weeks ago, we even had this great horned owl drop in for a drink.

great horned owl in ground water dish
  

For long-distance travelers, known stop overs are vital to successful migration. In the past week we've had a female western tanager and a male black-headed grosbeak. Two other migratory birds arrived here in the last 48 hours: a white-crowned sparrow and a male Townsend's warbler. The white-crowned sparrow stopped for food and water, but the warbler stopped to take a bath in our fountain this morning. The native plants may provide him with an insect snack, but we don't directly provide warblers with food. Water and shelter in native vegetation are the draw. 

CA towhee on raised birdbath

You can make a difference for long-distance traveling birds. 

A running fountain, a raised birdbath, or even a shallow dish of water on the ground. 

Different birds and animals have different preferences. Always make sure that the location is safe from domestic cats.

While I was writing this a Cooper's hawk came and drank from the dish. It may be one of the youngsters that spent hot summer days here in 2019. Sitting with their feet in the cool water helps birds cool down. The red-tailed and red-shouldered hawks prefer the raised bird bath. Rabbits and desert tortoises prefer the ground dishes.

Juvenile Cooper's hawks
 

Climate change challenges wildlife survival. Provide clean water and give back to the natural world. (Still water should be replaced every day or every other day.)


Wednesday, June 23, 2021

Unexpected Wild Carrot - Native or Introduced?


Gardening with native plants can be a challenge. Natives don't always thrive in the site you assign them. For example, the sedge below is growing, but it isn't thriving. Right beside it, the coyote mint (Monardella villosa) pictured above is thriving. 



This toyon grew from seed on its own and is the most robust toyon in our garden.

I noticed the lacy-leaved plant, below, coming up last winter and I let it grow, because I wasn't quite sure what it was. It was sprouting from the dirt of a nursery raised native that had petered out.

It got bigger and bigger. I've tried to let go of the term"weed," sometimes native plants come and they grow where they're suited, not where we want them. It looked too pretty to be a weed, but what was it?


It reminded me of a plant I had seen in wild meadows, commonly called: Queen Anne's Lace

 As it started to bloom, the answer was clear: wild carrot (Daucus carota) also called Queen Anne's Lace.

With a little investigation, however, I discovered wild carrot is an introduced plant from Eurasia. It is indeed the ancestor of domestic carrots and most likely came with early European immigrants to North America. The USDA Plant Database map reveals that it is found throughout the North East to the Mississippi Valley, expanding into the South, and all along the West Coast of the U.S. Some sources site it as growing in all fifty states. In some states, according to the Invasive Plant Atlas of the United States, it is considered an aggressive invasive. Like the carrot in your refrigerator, it has a thick taproot, difficult to pull out.

Some states villainize it and make it illegal to transport or sell the seeds. At the same time researchers are investigating the possible health benefits of its volatile oil. Wild carrot has long been considered a medicinal herb with diuretic properties. 


Where did this lovely specimen in my yard come from? I have no idea. Most likely, birds transported the seed, which have tiny burs on their edges. Birds occasionally bring black nightshade into the yard. Or maybe it was in the soil that came with that nursery plant. 

Will I remove it? The biggest claim against it is that it takes hold in disturbed soils and out competes native plants or grasses grown for livestock. It can be mildly toxic to livestock, in other words: this plant has evolved to protect itself from grazing animals. Because of its deep root, it holds unstable ground, but after several years all sources say that it gives way to the natives. Controlled burning doesn't reduce it, because it grows back from the deeply established root. 

Right now it is beautiful and somewhat contained. I think I'll leave it. We'll pick the flowers and not let it go to seed.

Another surprise nonnative - lawn shrimp 

April was Native Plant Month

Tuesday, June 15, 2021

Monarch Caterpillars!


What a surprise this morning, monarch caterpillars! And they are an inch and a half long.

We've been seeing an adult monarch butterfly (Danaus plexippus) a couple of times a week. The last few years we have been growing native narrow-leaved milkweed (Asclepias fascicularis) and the introduced tropical species (Asclepias curassavica) that is readily available at garden stores.

We've had little caterpillars in the past, but they seemed to get eaten by either a bird or a predatory insect. This is the first time that we have had caterpillars reach this size in years.

The group of monarch butterflies that live in California (west of the Rocky Mountains) do not migrate to Mexico with the main population from the southern Central and Eastern part of the U.S. This Pacific population overwinters along the coast in Southern California down into Baja. 

Loss of milkweed habitat has caused declines in this population. Most butterfly species lay eggs on a specific plant species and their caterpillars are dependent on that plant for food. Native milkweed can be a challenge to grow. I didn't realize that narrow-leaved milkweed dies back each winter. I thought I had killed it and took it out. Now I understand that it will grow back in the spring. Until my native milkweed is established, I supplement with the tropical species in a planter, to avoid it becoming invasive.

These hot days, with temperatures above 100 degrees are a challenge for plants and wildlife. I hope that our caterpillars make it to chrysalis. It would be great to contribute to a new generation of monarch butterflies.

Other caterpillars you might see in your CA yard

Backyard Butterfly Quiz

Mourning Cloak Butterfly

Monarchs and Jerusalem Crickets