Don't Blame Goldenrod for Hay Fever

The beautiful yellow flower sprays of goldenrod aren't the cause of late summer hay fever. The most common culprit is ragweed. Goldenrod is pollinated by insects and its pollen is heavy and sticky, while ragweed is wind pollinated. Dust-like ragweed pollen readily becomes airborne and that's why it ends up in our sinuses. 

Goldenrod is often blamed for hay fever because it blooms at the same time as ragweed and is very showy, while ragweed blends in with the background. Ragweed does have some redeeming features, however. It is a native plant with wildlife value, as birds eat the seeds. It's also an important colonizer of old fields and other disturbed areas.

Goldendrod flower sprays.

Ragweed has deeply lobed, "raggedy"  leaves.

Ragweed flowers are green.

Bumble Bees at Risk

I'm always delighted to see bumblebees in my garden, but, like many native pollinators, their future is cloudy. The  Xerxes Society has a great fact sheet on the status of bumblebees at http://www.xerces.org/wp-content/uploads/2010/08/bumble-bee-conservation-factsheet.pdf. Of course, the first thing on their list of things you can do to help is to plant a diversity of native plants for foraging bumblebees.

Native Plant Lecture & Field Trip in Loudoun

Tuesday, June 14, 2011 at 7pm Lecture on Native Ferns, Vines and Shrubs by John Magee, a local well established native plant landscaper, at the Rust Nature Sanctuary, 802 Childrens Center Rd., Leesburg, VA

Saturday June 18, 2011 at 8:30am join us for field trip on Native Ferns, Vines and Shrubs with John Magee to the home of Susan Abraham.Cost for class and field trip is $20 for ANS members and $25 for non members. To register please emailjulieg@audubonnaturalist.org

Alexandria Flora Project

Check out the Alexandria Flora Project at website at http://alexandriava.gov/recreation/info/default.aspx?id=22560, especially Rod Simmons power point presentation on native spring wildflowers in the DC region.

Native Bees Emerging

Native bees, vitally important pollinators, are emerging from their ground nests now. Rod Simmons, Natural Resources Specialist/Plant Ecologist for Alexandria, circulated this photo of a large aggregation of nests Alexandria. See below for Rod's discussion of this site. You can provide nesting habitat for these harmless bees by maintaining a patch of bare earth in your yard.

Steep bank of loamy Potomac Formation “Golden Sand” (Tony Fleming, geologist) extensively colonized by hundreds of Solitary Bees.  Site is southwest-facing corner of Immanuel Lutheran Church and School at corner of Belleaire Road and Russell Road in the City of Alexandria, Virginia.  “[Solitary Bee]…stings are unable to penetrate human flesh and they do excellent pollination work on early fruit... Unfortunately, some members of the public still think that they are dangerous pests - so if beekeepers get a call to ‘deal with’ swarms of bees living in holes in the ground, this is a great opportunity to do a little education.” (http://www.kilty.demon.co.uk/beekeeping/solitarybees.htm).  More information at: www.earthlife.net/insects/solbees.html  And of course our local experts Alonso Abugattas, LB Nature Center Director; Cliff Fairweather, Environmental Education Director and Naturalist at Audubon Society; John Walsh, City of Alexandria Horticulturist; Mark Kelly, Ford Nature Center Director; Sam Droege at USDA; and others.  Photo by R.H. Simmons, March 22, 2011.

Cat and Birds

A new study on the impact of free-roaming house cats on bird populations has been released and a recent NY Times article describes the findings:

http://www.nytimes.com/2011/03/21/science/21birds.html?_r=2&src=me&ref=homepage

This is just one more in a long line of studies demonstrating the enormous impact free-roaming house cats have on birds. Some argue that the impact of house cats on bird populations pales in comparison to habitat loss and degradation as a risk factor for native bird populations, but free-roaming and feral cats are actually part of the impact of habitat loss and degradation due to expanding residential development. House cats can actually extend the habitat impact of residential development because they often hunt in adjacent remnant patches of natural habitat, such as woodlots and local parks. They also diminish the efforts of nearby homeowners trying to restore some of the lost habitat for birds on their properties through Audubon at Home and similar programs. Even if these cats stay close to home, they prey on birds and other wildlife that enter their owner's properties.

House cats are subsidized predators that don't face the same constraints nature places on wild predators. We take care of most of their needs, while wild predators must budget their energy between hunting, finding mates, caring for young, defending territory, avoiding predators, overcoming illness and other activities. Cats have the extra energy to indulge in "leisure hunting", while wild predators have to focus on capturing just enough prey for themselves and their young. Also, wild predator numbers in a given area are limited by factors such as the available prey, competition with other predators, availability of suitable habitat, and mortality from animals that prey on them. Because we take care of them, house cat populations can occur in far higher concentrations than is possible for wild predators.

If you have a cat that simply cannot tolerate being kept inside full-time, try keeping it inside until after breakfast and making sure that it is back in the house before dinner. This keeps it indoors during the twilight hours, when birds and other wildlife are most vulnerable to predation. Cat owners should also be aware that there is a new dog in town that poses a mortal danger to their pets -- the eastern coyote. Coyotes are now well-established in Northern Virginia and they tend to eliminate medium-sized predators, including house cats, that compete with them for prey.

Free-roaming house cats aren't the only risk to birds posed by humans and our activities, but, as the study in the NY Times article makes clear, they are a significant one. Conservative estimates of the annual toll on birds in the U.S. are 100-150 million and higher estimates go to 1 billion. Untold numbers of small mammals, reptiles and amphibians are lost as well. Ultimately, it is the cumulative impact of many factors -- cat predation, habitat loss and fragmentation, pesticides, building lights, climate change, among others, often operating in concert, that put bird populations at risk. We need to address all of these, but cat predation is one on which every cat owner can have an immediate impact .

Saving a Nearly Extinct California Native Plant

Here's an interesting video of the resurrection of a nearly extinct native plant in the San Francisco area of California.  http://video.pbs.org/video/1841603655