Frog Blog - African Clawed Frogs

An alert and concerned citizen sent the following message recently to the Oregon invasive species network:

“Hallmark stores is selling live frogs - advertised as African frogs. They are sold in very small aquarium type containers. I was shocked to see them selling live animals, but it concerned me that they may be importing a potential invasive species. I'm just wondering if the Department of Ag needs to be notified of this practice.”

Kudos to the sender for recognizing there could be a risk and alerting the authorities. Oregon Dept. of Fish & Wildlife responded and here is their reply:

“OSP and I checked a Hallmark store about month ago and found that they are selling the dwarf clawed frog (Pipidae hymenochirus) in their frog kits which is a non-controlled species in Oregon and legal to sell. The prohibited species is the African clawed frog (Pipidae xenopus).” -Rick Boatner

I’m impressed that ODFW had been to the store first and already knew live frogs were on sale there. It is also commendable that they have reviewed frogs in the pet trade and sorted them into those that are a potential problem for Oregon and thus prohibited, and those that aren’t a threat and are legal to sell. Well done, ODFW!

The concerned citizen goes on to say,

“Even if the frog is 'legal,' I find it offensive that they are selling live animals and have written to their corporate office to state my objection.”

This is a moral question, separate from their potential to be invasive. Oregon Department of Agriculture staff members have debated a similar issue related to butterfly releases at weddings. Some new brides and grooms want to release commercially available butterflies during their ceremony. At first blush this seems like a charming idea, but what if the butterflies are not native to Oregon? Could they become invasive? We already have one invasive butterfly species here, the cabbage butterfly (a.k.a. imported cabbageworm) – a common white species that lays its eggs on the broccoli and cabbage plants in your garden.

Sometimes couples propose using tropical butterflies that wouldn’t survive here and don’t pose an invasive species threat. Is that OK? Is it right to release a wild animal into an inhospitable environment? To me it just doesn’t seem like an appropriate gesture, especially for a joyous event celebrating a new beginning.

Our current policy is to allow releases of widespread, native species only. One former ODA Entomologist collected local butterflies the day before his wedding and kept them overnight in a cooler. He told me they were a little slow to warm up when the cover was opened during the reception, but once they did, it was a pretty sight when they fluttered out.

I’ve also heard of people releasing white homing pigeons (a.k.a. “doves”) at weddings. Apparently they fly around and around above the guests to get oriented before heading home. I love that idea. No risk to the environment, no moral issues, and they can be recycled!

Dan Hilburn

Growing Howard the Pumpkin

I grew up on asphalt just outside of Boston, Massachusetts. I was such an urban kid that I did not learn until I was 17 years of age that much of the plant foods we eat are actually grown from seed. For those of you that grew up on a farm, that's probably a pretty astonishing fact, but the reality is that many urban kids don't have a connection to agriculture and have little understanding about where real food comes from - that is, food that doesn't come out of a package.

It wasn't an amazing epiphany that resulted in my advanced educated state. Rather, as a freshman at the University of Maine, some of my older co-workers gave me a handful of seeds to plant in a small garden plot outside of a place we were staying during my summer as a harbor seal researcher. I thought it was one of their usual tricks - let's play another one on the freshman. To this day, over 30 years later, I remember looking at the seeds and laughing and saying, "Yeah sure, I'm going to put these in the ground, and we're going to eat vegetables the rest of the summer." I also remember the looks on their faces when they realized I actually thought it was a prank. It was a partial look of "We have a LOT of work to do with this kid," and an incredulous, "How can this be?"

I played along with the charade, but the seed quickly germinated, and I've been hooked on gardening ever since. I love sticking seeds in good soil more than most people enjoy the finer things in life. I'm fascinated by soil tilth - that incredible formula for productive, healthy soil that consists of half soil and one quarter air and water. Any farmer that has too much or too little of any of these components usually has problems with crop production.

What does any of this have to do with invasive species? Lots.

If we want our kids to value healthy ecosystems and the native fish and wildlife that live there, they must understand, be aware of, and appreciate how things grow and where food comes from. They need to be excited about what healthy soil can produce so they know what can be lost as invasive species outcompete and displace native plants.

So I'm on a mission this summer to get the neighborhood kids excited about gardening. To do that, we're not only growing our annual large vegetable garden - we're growing a pumpkin. But this is no ordinary pumpkin - this is Howard, the Giant Pumpkin. Since April, I've been taking care of Howard as though he were my own offspring. He soaked in seaweed water for 4 hours before I planted him in 85 degree potting soil (giant pumpkins will not germinate in soil less than 85 degrees - I know that because I tried to germinate him at 75, 80 and 83 degrees, with no success - just like the books said). I hardened him outdoors for five days longer than recommended because I had a sneaky suspicion Oregon might experience the kind of late cold, wet spring we now have. And last weekend, my husband and I constructed a little greenhouse over him to shelter him from the cold, wet rains and warm the soil around his happy roots.

There are many people that grow giant pumpkins in the 1,600 pound category. I don't know if Howard will achieve that weight because we're growing him organically, without any chemical additions to the soil. He's surrounded by flowers that will help repel insect pests (thanks to the neighbor kids that enthusiastically planted them). He's basically livin' the dream.

And I'm living mine, too - to get people fired up about gardening and developing a relationship with the soil and the outdoors that will ultimately translate into people leading sustainable lifestyles and caring about the stewardship of our natural resources.

If you want to track Howard the Pumpkin during the summer, you can follow him on Facebook - he has his own Facebook page, since he's a public figure in our neighborhood. His website is
http://www.facebook.com/home.php?#!/pages/Howard-the-Pumpkin/125409454143427?ref=ts

And to my college mentors? Thanks - for a lifetime of enjoyment. And Howard thanks you as well.

Last week I wrote about an edible plant (Chinese water spinach) that has gone from High to Low on our Oregon weed threat meter. This week I’m writing about garlic mustard, another edible plant which is headed the other direction.

Here are two excerpts from recent emails from Tim Butler, ODA Noxious Weed Program Manager:

“This Monday, May 3rd, Dan Durfey, Umatilla County Weed Supervisor and Dan Sharratt, ODA Regional Weed Specialist, confirmed a site of garlic mustard along the Umatilla River near Pendleton. They have done an initial delimitation survey and have detected other infestations. It currently looks like garlic mustard is spread over about 5,700 gross acres in the watershed and along about 20 miles of the Umatilla River.”

“This is a significant find since the next closest known infestation is in Multnomah County. This really expands the range of this weed, so central and eastern OR counties need to be on the lookout for garlic mustard particularly in riparian and forested areas. Here is a link to the ODA garlic mustard web profile that will provide additional information:”

http://www.oregon.gov/ODA/PLANT/WEEDS/profile_garlicmustard.shtml

“. . . we know about the other outlier infestation that started at the Valley of the Rogue State Park in southern Oregon. We have known about that infestation and in fact the Oregon State Weed Board has funded a grant for that project. This season additional survey has revealed that the garlic mustard has spread on down the Rogue River drainage.”

Garlic mustard spread sounds yummy, but this is a disturbing development. A decade ago, garlic mustard wasn’t even on ODA’s radar screen. I remember the first call I received from a concerned land manager in Corbett. He was having trouble finding anyone who would listen to his concerns, including me – I didn’t know what he was talking about. Since then Portland-area land managers and weed warriors have learned a great deal about garlic mustard, it can spread faster than warm butter on hot pancakes.

Garlic mustard was introduced to the eastern U.S. in 1860’s from Europe. The first Oregon record is from 1959 in Multnomah County. According to Wikipedia, leaves, flowers, and fruit are edible and are said to have a mild garlic – mustard flavor. I haven’t tried it, but watching this invasive species spread is leaving a bad taste in my mouth.

Dan Hilburn

Phantom Water Menace

Chinese water spinach (Ipomoea aquatica) is an edible plant; it is a popular vegetable in Asia. Chinese water spinach is also a noxious weed (Federal) because in the right conditions, it can take over lakes and ponds. The US Department of Agriculture allows states to decide whether to allow importation for human consumption via permit or not. The Iowa Department of Agriculture recently requested input from other states. I passed on Oregon’s experience and monitored the other responses. In general, northern states allow Chinese water spinach; southern states don’t.

In 2003, we were approached by USDA and asked whether we’d accept Chinese water spinach in Oregon. Portland State University stepped up and did a risk assessment: http://www.oregon.gov/OISC/docs/pdf/ipaq_ra.pdf

Here is an excerpt from the conclusion: “. . . due to the requirement for hot, humid conditions for growth and the failure of I. aquatica to establish in more temperate areas of Asia, where it has been an important food for several centuries, we conclude that there is a low risk that I. aquatica could establish, invade, and create a nuisance condition in Oregon rivers, streams, lakes, and drainage and irrigation canals.”

The authors even bought some plants at an Asian market and tried to rear it without success. This plant grows amazingly fast in the tropics and in greenhouses, but we don’t have to worry about it becoming an invasive weed in Oregon.

This is a good example of how weed problems are regional. Just because a plant is a weed elsewhere, doesn’t mean it would be a weed here. Before adding weeds or other invasive species to lists of prohibited species, we need to get in the habit of doing a risk assessment. In most cases, this is essentially a literature review answering these questions:

- What is the likelihood of introduction, establishment, and spread?
- What would be the ecologic and economic consequences if it did establish?

The Oregon Invasive Species Council is making good headway on doing risk assessments for all species on our list of 100 Worst Invaders. It won’t surprise me at all if some species currently on the list turn out to be phantom menaces. Others, of course, will pose more risk than we currently imagine. The value of doing these risk assessments is that it allows us to focus on the highest priority invasive species and not waste time and resources on low risk species like Chinese water spinach.

Dan Hilburn