Wednesday, June 30, 2004

Water primrose primer

Workers at The Nature Conservancy's Long Island, NY chapter are spreading the word about the recent discovery of established populations of an invasive water primrose (Ludwigia sp.) in the Peconic River. A smart biologist has already documented the invasion with photos (see below). As reported by the ISW back in 2003, water primrose is prime mosquito habitat. If you're in the area and you think you've spotted this plant, you can find contact information for TNC's Long Island office here. TNC is considering their options for eradication or management as they study the situation more closely.

Ludwigia sp. on the Peconic River

Ludwigia sp. on the Peconic River

(Thanks to Andy Senesac for granting permission to use his photos.)

Tuesday, June 29, 2004

Not so new, but still rings true

Back in 2001, Don Schmitz and Daniel Simberloff published an article titled Needed: A National Center for Biological Invasions. In it, they discuss the necessity of having coordination among the various regional and federal agencies, experts, and non-governmental groups involved in invasive species management. It may be three years old, but the article is still quite valid today. Sharing of resources will likely be the key to controlling invasives, especially in a time where environmental funds are being stretched thin. And invasive species (humans notwithstanding :-)) don't give a darn about political boundaries.

Monday, June 28, 2004

Florida is in deNile

The News-Press has another article about the Nile monitor lizard (Varanus niloticus) eradication program currently in effect in Cape Coral, Florida. So far biologists have caught and euthanized about 60 of the estimated 500-1000 lizards thought to be living in the city. The first ISW post about this was back in July 2003 (unfortunately that older article is no longer available on the web). Also from The News-Press is this article about a temporary reprieve for other exotic animals in Lee County, including iguanas (Iguana iguana) and peacocks (Pavo cristatus).

Thanks to a member of the ALIENS-L listserver for posting a link to the story.

Sunday, June 27, 2004

Registration Required

The Minneapolis Star Tribune just finished an excellent series on invasive species in the Great Lakes. Unfortunately, you will have to proceed through an annoying but free registration process to read all of the articles. Most interesting is this article from June 9th, which contains a list of 179 species in the Great Lakes marked as invasive (and describes the sources, bravo!). There's also this article about the lack of thorough ship-checks, a story about a woman's unpleasant encounter with a silver carp (Hypophthalmichthys molitrix), and an interesting piece about the attempt to prevent the spread of carp via an electric barrier. To see all related stories, you'll have to search the Star Tribune's archives.

Tuesday, June 22, 2004

Monk Parakeets II: Problem or Not?

Monk parakeets are here to stay in many areas of the United States. Even a coordinated campaign would probably fail to eradicate them altogether, given their large numbers, fast, powerful flight, intelligence, and adaptability in nesting and feeding, not to mention the problems associated with removing them from urban environments. Should the state even try at this point? Are Monk Parakeets even a threat?

One characteristic of monk parakeets has already caused frustration among people, and considerable destruction: their attraction to utility poles as a nesting substrate. Electrical utilities in Florida, Texas, and Chicago refer to them as "feathered rats", and have taken to removing nests from their poles. In some cases the heavy bulk of sticks have caused the transformers to overheat and catch on fire. The removal is usually met by an outraged Chicago the electrical company knocked down a nest containing several eggs and nestlings a few years ago. This "strategy" of nest removal is a PR nightmare, and ultimately ineffective. After three different nest removals in Chicago, I witnessed the birds immediately rebuilding the nests after the workers left. Are monk parakeets an agricultural threat? Data from their native range are hard to come by, and what has been published is often in Portuguese. No estimates of actual crop damage by monk parakeets are available. Typically, they are blaimed for much more damage than they cause because they are much more visible than an insect or a fungus. One Brazilian study found moderate percentages of corn and wheat in the crops of monk parakeets, but the sample size was small. This method can also be biased by the timing and location of sample collection. In the United States, a master's student studying monk parakeets in Florida told me a few years ago that she had observed monk parakeets and other naturalized parrot species feeding in groves of exotic fruit species (e.g. mango, lychee, longan). However, I don't think she was ever able to quantify the damage. No reports exist of monk parakeets feeding in other agricultural crops (e.g. the extensive grain fields surrounding the Chicago area). I suspect that monk parakeets will become a minor problem in Texas and Florida fruit orchards, but in harsher environments like Chicago or New York they will be unable to spread to agricultural areas. I found in my study that monk parakeets almost exclusively eat bird seed from backyard bird feeders during the winter months. They might be unable to spread without supplemental feeding by urban and suburban residents. Do monk parakeets compete with native species? An interesting question, but it can't really be answered yet. Their numbers are not that large, they don't nest in cavities like many parrots, and they occur mostly in disturbed environments. Monk parakeets might outcompete some species at bird feeders in Chicago (such as Cardinals). Some people (mostly non-scientists) have argued that the monk parakeet could fill the niche of the long-extinct Carolina parakeet, but that assertion seems fanciful at best. Overall, monk parakeet populations don't offer much cause for concern yet, but close monitoring is needed in Florida and Texas. Could control measures be taken against these local oddities even if the authorities desired it? Maybe at their first appearance, but favorable public opinion is now entrenched in favor of the birds in many places. When federal authorities threatened to wipe out the Hyde Park, Chicago, population in the 1980's (shortly after Mayor Harold Washington's death...he was a big supporter), a Hyde Park lawyer formed the Harold Washington Memorial Parakeet Defense Fund and thwarted the authorities. When the oldest monk parakeet nesting tree cracked and fell a few weeks ago in Hyde Park, the authorities actually helped transport young parakeets to a nearby tree! Many people in the neighborhood have adopted fallen parakeet chicks as pets over the years...those parakeets are untouchable at this point (except for those on the utility poles, but I hear they have been slowly moving to the trees as their nests are continually destroyed). For an independent example of people falling in love with an introduced parrot species, check out this website, book, and documentary film about a man who looks after the Red-headed Conures breeding in San Francisco! This story (and others like it) is ultimately more about the satisfaction that humans derive from animals, rather than about the animals themselves or the environment. I'm sure these parrots would have been just fine without someone feeding and taming them. Let's hope these birds don't become a pest in California, because they certainly aren't going anywhere.

Sunday, June 20, 2004

Monk Parakeets I

Jason South of Borneo Chela here, pitching in while your regular host braves the verdant jungles of Costa Rica.

Here is the first of two posts on Monk Parakeets (Myiopsitta monachus), an introduced parrot that has established several breeding populations in the United States.

Many invasive species are subject to human disdain, or at least indifference, because they are a diminutive weed or foul, slimy thing that chokes up pleasant ecosystems with a bland uniformity. However, some nonnative species have been intentionally or unintentionally released in to the environment due to their cultural significance (i.e. beauty, popularity as companions). The ubiquitous house sparrow (Passer domesticus) and common starling (Sturnus vulgaris) are archetypal; both were intentionally released in to the US on several different occasions by English immigrants to provide a constant reminder of home (one particular individual wanted to populate the US with the birds mentioned by Shakespeare!). Over the past 30 years, more than a dozen parrot species have escaped or been released in to the wild in the US. The most numerous by far, in terms of both geographic locations and numbers of individuals, is the monk parakeet. This medium-sized parrot is native to the temperate grasslands of Argentina, Paraguay, Uruguay, and southern Brazil, and is common throughout its range. THe planting of eucalyptus has allowed the monk parakeet to expand its range in the pampas region of Argentina, due to increased availability of nesting substrates. Thousands of these parrots were imported into the United States in the late '60's and early 70's to be sold as pets under the name "Quaker parakeet". Shortly thereafter, the first free-flying populations began appearing, mostly near dense population centers such as Chicago and New York City. As of 2001, monk parakeets had been recently recorded nesting in 14 states across the country. Texas and Florida harbor the largest breeding populations. Population estimates are not available, but thousands of monk parakeets are likely flying free in Austin and the east coast of Texas, and throughout South Florida (especially Miami-Dade county and the Sarasota area). The parakeets in Florida have actually been counted, but the data have not been published because of fears that the state or federal government might seek to control the population (more on that in part II). A few dozen are nesting in Brooklyn, NY, especially on the stadium lights of a particular high school. The population I studied in Hyde Park, Chicago (location of the University of Chicago) contained between 200 and 300 birds in Spring 2000 by my own count, with several dozen more nesting throughout the city and suburbs. How did so many parakeets make their way in to the wild? A combination of accidental escapes and intentional release. The story in New York, perhaps apocryphal, is that a crate containing monk parakeets fell and broke open at JFK airport in the early 1970's. The story in Chicago is even less clear, but newspaper articles suggest that the birds were first widely noticed in 1971, and were confirmed as breeding in 1979. These parakeets, and others around the country, were probably intentionally released by frustrated owners. Monk parakeet are incredibly friendly, gregarious, and easy to tame, but also ear-splittingly loud. They can be heard, even if far out of sight, all over Hyde Park as they call to each other in flight. How do they survive in the wild? The mild subtropical climates of Texas and Florida are a welcoming environment, but what about the harsh winds and winters of Chicago? Nests and birdseed are the likely answers. Monk Parakeets are the only parrots to build a nest that they use all year round for roosting. A pair will chew off hundreds of twigs that are then woven into a closed chamber with a single opening...once one of these chambers is built, other pairs will build their chambers on to the first one, thus creating a large social complex. A few birds huddled together in a chamber surrounded by other birds and chambers are likely to be warmer than a birds roosting on a naked branch. Monks also have a voracious appetite for bird seed, and will sit at feeders for hours in Chicago when it is cold outside (this supplemental feeding might limit their range in the northern states, however).

In a few days I will report on the problems they present as non-native species, as well as the social factors that will likely prevent government authorities from taking action against their spread in most parts of the United States. A few states have banned monk parakeets as pets, but only California strenuously enforces their own regulations. The state of California will confiscate and euthanize both pet and wild monk parakeets, even though they have allowed ten other species of parrots to breed unchecked in the wild!

Saturday, June 19, 2004

Everybody Polka!

If you live in the U.S., chances are that you've owned a pot of the pink polka-dot plant (Hypoestes phyllostachya), a common houseplant native to Madagascar. But if you live in Costa Rica, perhaps you've seen this plant naturalizing in disturbed areas. Below is a photo of polka-dot plants lining a trail near protected bellbird habitats in Los Llanos preserve. It dominates parts of the trail, and can be found mixed in with the grasses in the borders of the abandoned pastures in the preserve. A study back in 1999 noted that native butterflies were unsuccessfully attempting to use polka-dot plant as a host species for their eggs.

image of pink polka-dot plant

Monday, June 14, 2004


image of cane toad

Our group has sighted at least 2 different cane toads (Bufo marinus) on the front steps of the research station here in Costa Rica, since we arrived just two days ago. Apparently they see it as a giant feeding ground, since insects congregate when the lights are on at night (one toad was spotted eating a moth). There seems to be some question as to the exact native range of this species, but cane toads haven't been in Monteverde very long. It certainly seems like their presence would be a threat to native insects. Perhaps someone in Costa Rica needs to start a cane toad leather goods company.

Saturday, June 12, 2004

Costa Rica

Posting will be sparse for the next two weeks, as I have just arrived in Costa Rica. While best known for its tropical rainforests and amazing native biodiversity, this country does have it's fair share of invasive plants. We saw a lot of busy Lizzy (Impatiens walleriana) and many Mazana rose (Syzygium jambos) trees on the way up to Monteverde.

While I am away, keep your eyes peeled for the ISW's special guest poster, Jason South, who maintains the Borneo Chela blog.

Thursday, June 10, 2004

Gear of Geekery

Today I received several items I ordered from the ISW store. I am happy to report that the Japanese knotweed mug looks very cool. The Garlic Mustard Patrol T-shirt looks good as well, and wins points for being printed on a nice, soft, Hanes cotton T. If you want a Purple Loosestrife Patrol Cap, make sure you get the white one; I ordered the khaki, and the print barely shows up.

Wednesday, June 09, 2004

Pink Robinias

I've been tracking pink robinias this year, which has been especially easy the past few weeks, while they've been in flower. Turns out the plants I see in Metrowest Massachusetts are at least two different species: clammy locust (Robinia viscosa) and bristly locust (R. hispida). Along with the white-flowered black locust (R. pseudoacacia), they are considered native to the U.S., but only the southeastern region. Check out a gallery of pink-flowered specimens I've uploaded here. Some of them seem to combine characteristics of the three species, so perhaps there is some hybridization going on.

Tuesday, June 08, 2004

Blue Hawaii

The Pacific Cooperative Studies Unit (PCSU) has partnered with the National Park Service to bring us online versions of a whole slew of paper literature. Most interesting so far, to those studying invasive species, would be the book "Alteration of native Hawaiian vegetation-Effects of humans, their activities and introductions." It includes chapters about the impact on the island of aboriginal peoples, the more recent planting of alien trees, and feral animals. Books and reports are available in .pdf format, and the site promises additional interesting titles are coming soon.

Thanks to a member of the ALIENS-L listserver for sending a link to the site.

Monday, June 07, 2004

Going Batty

A pair of orbicular batfish (Platax orbicularis) have been spotted off the coast of Florida, and tomorrow scientists are hoping to catch them and remove them from the waters of the Florida Keys. As reported by news-journalonline Florida, the scientists are worried that the batfish will breed and provide competition for native fish species. It is suspected that the fish were released by an aquarium hobbyist after they outgrew that person's tank or interest.

Sunday, June 06, 2004

Sunday (Saturday) in the Park

A bit late, I know. See last week's edition for more leads.

Saturday, June 05, 2004

Snail Watch

According to this story from the News & Observer, North Carolina is taking the discovery of giant African land snails (Achatina fulica) in Wisconsin very seriously. Officials are concerned that teachers in their own state may have used the snails in classroom projects, and could be releasing them into the wild now that school is out. Read about the Wisconsin snails in this old ISW post. Bonus points to the News & Observer for using scientific names.

Thanks to Alex L. for sending in a link to the article.

Friday, June 04, 2004

Dye, Garlic Mustard, Dye!

Want a unique way to use up all that garlic mustard (Alliaria petiolata) you've been pulling up? How about creating some neat tye-dyed t-shirts using a dye made from your chopped up invasive plants? Marc Imlay, from the Maryland Native Plant Society, has generously given me permission to post his "recipe" below.

  1. Gather plant material for dyeing.
  2. To make the dye solution: Chop plant material into small pieces and place in a pot. Double the amount of water to plant material. Bring to a boil, then simmer for about an hour. Strain.
  3. Getting the fabric ready for the dye bath: Muslin, cotton and wool work best for natural dyes. You will have to soak the fabric in a color fixative before the dye process. This will make the color set in the fabric.
  4. Soak fabric 40 minutes in warm water.
  5. Pre-mordant one hour with aluminum potassium sulfate (alum). Divide the weight of the material to dye by four and weigh out that much alum mordant. Add the fabric to the fixative and simmer for an hour (180 - 200 degrees F).
  6. Rinse the material and squeeze out excess. Rinse in cool water until water runs clear.
  7. Now you can add your fabric to be dyed. Dye one hour (simmer) stirring occasionally for evenness of color.

More information about using plants to make natural dyes can be found here.

Wednesday, June 02, 2004

Knotweed in the News

I managed to get a brief call back to a reporter today while I am out on Nantucket island for the Nantucket Biodiversity Initiative. The result is a blurb with my name in a nice AP article about Japanese knotweed (Fallopia japonica). Thanks Dan!

(P.S. - Nantucket is full of knotweed!)