Monday, August 31, 2009

Invasive Species in the St. Lawrence Seaway

The St. Lawrence Seaway, the major shipping canal connecting the Atlantic Ocean with the Great lakes, has become a major conduit for invasive species. About a third of invasives in the Great Lakes region have come by that route, and many of them end up elsewhere in the continent.

Zebra and quagga mussels from the Black Sea clog intake structures for municipal water systems and power plants. The mussels also gobble plankton so voraciously that little is left for other organisms. Round gobies and other invasive fish beat out native fish for food supplies, harming the lucrative commercial and sport fishing industries. Ballast is even blamed for the emergence of viral hemorrhagic septicemia, often called "fish ebola," resulting in large fish kills in the past several years.

And as infected pleasure boats are hauled to other lakes or species swim and float into tributaries, or even the Mississippi River, invasive species that came in with the ballast are spreading throughout the United States. Large quagga and zebra mussel colonies have been found in California and Nevada and are threatening to spread through California's many miles of municipal water pipes.
Many of the invasive species have come through ballast, which is not well regulated.
There are no federal standards for ballast treatment, although the Environmental Protection Agency and the Coast Guard are working on requirements that should reduce the amount of live organisms in ballast water.

Since 1993, ships have been required to exchange their ballast in the Atlantic before entering the Seaway, replacing water from whatever port they had last visited with high-seas water containing little life.

But until 2008, U.S.-bound ships loaded with cargo and hence containing no ballast were exempt from any regulations. These ships are called NOBOBs, for No Ballast on Board. But their "empty" ballast tanks contain many tons of muddy slop teeming with bacteria, small marine organisms, eggs and larva.

NOBOBs typically unload their cargo -- often steel -- in Great Lakes ports like Detroit and Cleveland, suck water into their ballast tanks, then head to other Great Lakes ports -- Duluth, Toledo or Milwaukee -- to load up on grain and dump their ballast, now mixed with the biologically rich mud.
Stricter regulations are supposed to be on the way, but have been slow in coming.

Sunday, August 30, 2009

Obama and the Environment at Seven Months

This week Mongabay featured an editorial outlining several areas where the Obama administration has fallen short on environmental issues. Seven months into a presidency is probably too soon for a full evaluation. However, there have been a few disturbing trends. For this blog, the most relevant area is biodiversity.

Of course, wolves are just one of hundreds—or more likely thousands—of endangered species in the United States. The Obama administration started out swinging when it overthrew a Bush administration decision that would have gutted vital aspects of the Endangered Species Act, but since then it has moved forward slowly on protecting species.

Just yesterday, the U.S. Fish and Wildlife Service stated that twenty-nine species will go on to be considered for protection under the ESA. So, while they are not covered yet, they have made it to the next round. Yet at the same time, it was announced that nine species were dropped from consideration, such as the Ashy Storm-petrel, a sea bird off the West Coast which has already been classified by the IUCN as Endangered. To add to the frustration, in February the U.S. Fish and Wildlife Service turned down protections for a staggering 169 species.

While just considering protecting species under the ESA is a big change from the prior administration, which diluted and ignored the ESA whenever it could, species reviews are backed up and environmentalists are saying they are already unhappy with Ken Salazar's decision-making regarding endangered species. Even if all 29 species now being considered become protected that's only a little more than 7 percent of the original species proposed.

The world is in the midst of a biodiversity crisis—and maybe even a mass extinction—and the United States is no exception. If the world's wealthiest, most powerful nation chooses not to save its dwindling biodiversity what hope is there elsewhere?
Salazar's handling of the Endangered Species Act is hardly the only issue mentioned in the editorial that bears on biodiversity. The practice of mountaintop removal mining destroys important forest habitat even as it poisons waterways, yet the EPA continues to approve permits. Clearcutting broad swaths of national forests likewise puts additional pressure on forest specialists. Even alternative energy can have negative impacts on biodiversity – ethanol especially but also large solar and wind arrays, if not sited and managed properly.

Saturday, August 29, 2009

Extinct Iridescence

Photo credit: Jakob Vinther/Yale University

A study announced this week determined that some ancient birds had iridescent black feathers, much like modern grackles or starlings. The analysis is based not on some new discovery but on fossils that had been stored in a museum collection. The example shown above, one of the fossils used in the study, does not look particularly glossy or black, at least not to my eye. However, ornithologists were able to reconstruct its original appearance based on the structure of pigmentation.
"[The arrangement of melanosomes] implies that this guy had a black plumage with a very glossy metallic, coppery, greenish, or bluish sheen to it," said Prum, whose new research appears online today in the journal Biology Letters.

The exact details of the iridescent color depend on how light would have reflected off the melanosomes and the layer of keratin, or protein, just above them. The keratin layer decomposed during fossilization.

"What you see is a beautifully smooth surface made of the melanosomes packed together," Prum said.

"And that beautiful smooth surface is the kind of uniform layer that characterizes the melanin distribution within an iridescent feather. We don't see that in a crow or other plain black bird."
The linked article includes a note of caution from another ornithologist to the effect that fossils provide incomplete information about an organism's color. The loss of keratin in particular might change how a fossil appears in the lab. However, it is still and interesting finding, and I am excited at the prospect of more accurate depictions of these long-extinct animals.

Friday, August 28, 2009

Loose Feathers #202

Yesterday my laptop's screen started doing its best impression of a dead cuckoo. The good news is that I have an older computer I can use in the meantime. The bad news is that most of the material I had gathered for this week's Loose Feathers is on the laptop, without an easy way to retrieve it with two-thirds of the screen blacked out. So instead of the usual bird news aggregation, this edition just includes some of the interesting bird blogging that I have come across this week.

Birds in the blogosphere

Carnivals and newsletters
Bird bloggers visit Queens
Unfortunately I missed this gathering because I mistakenly assumed the downpour we were getting in Central Jersey would be replicated in Queens. Hopefully I can make the next meetup.

Wednesday, August 26, 2009

How Much for That Froggie in the Window?

This gray treefrog (Hyla versicolor) was making use of an abandoned nestbox at Hidden Valley. When I first approached, the treefrog crawled further back into the box, but as I stood there, it crawled back to the front and stuck its head out. Its markings blend into the box very well.

A few bugs I have not identified were hanging around the entrance to the hole. I imagine they would be best advised not to go in.

Tuesday, August 25, 2009

Photo Study of a Dead Cuckoo

Yesterday, I saw a Black-billed Cuckoo. While not a rare species, it can be a difficult bird to find, even during migration. Unfortunately it was deceased. This cuckoo was lying in the bushes outside my cousin's house.

The cause of death is unclear. There were no visible wounds, which rules out a predator, like a raptor or a cat. However, its neck is broken, and there is some sort of shiny fluid around the bird's face (visible more clearly in the photo below). It may have crashed into one of my cousin's front windows and died from impact. A second possibility, since there was heavy migration the previous night, is that the bird died from exhaustion and broke its neck upon hitting the ground.

This was an immature Black-billed Cuckoo, which is apparent from the buffy shading on its neck. The long tail feathers also do not have as bold of a black and white pattern as would be expected on an adult. Yellow-billed Cuckoos, by the way, have much larger white spots on their tails, making the tail pattern an easy way to identify a perched cuckoo if you cannot see its bill.

While Black-billed Cuckoos have much less rufous on their wings than Yellow-billed Cuckoos, they still retain some. Their rufous is hard to see in the field, as it blends in with the dominant brown, but in the hand it shows much better.

In contrast to the dark upper wing, the underside is creamy white.

I was sorry to encounter such an awesome bird in such unfortunate circumstances. However, it was interesting to see some of its features up close, in a way that is rarely possible outside of a banding blind or a museum collection.

For larger images and a few more photos, see the cuckoo set on my Flickr account.

Monday, August 24, 2009

Not a Wasp, But a Fly That Looks Like One

On Saturday, I posted a series of photos of insects that I found recently in the garden. As it turns out, I identified one of them incorrectly. The photo below shows two wasp-like insects, both of which I originally identified as wasps.

The insect on the left is not actually a wasp but a mimic fly, in the family Conopidae. This individual is very similar the Kaufman guide's illustrations for the genus Physocephala. (Thanks to Anita Gould, whose post on Flickr brought the mistake to my attention.) Flies in this family, known as the thick-headed flies, are often found around flowers and mimic stinging insects, possibly to fool predators into seeking easier prey. In this case, the ruse was enough to fool me.

Despite its appearance, this is clearly a fly. The telltale sign is the single set of wings attached to the thorax. The shape of the antennae and hind femurs are also clues. You can see the single set of wings in the photo below.

Bees and wasps, meanwhile, have two sets of wings. The photo below, a Philanthus wasp, does not have great detail. However, it is just possible to see both a forewing and a hindwing attached to the right side of its thorax.

Like many wasps, flies in the family Conopidae parasitize other insects, in this case solitary bees and wasps. According to the Kaufman guide, female Conopids drive flying bees to the ground and hold them while they force an egg into the host's abdomen.

Saturday, August 22, 2009

A Leatherwing and Wasps

Update: One insect was originally identified incorrectly. See here for an explanation.

As the season has shifted into late summer and different plants have matured and bloomed, I have been seeing a different set of insects around the garden. Here are a few that I found yesterday.

First up is a Pennsylvania Leatherwing (Chauliognathus pennsylvanicus), a soldier beetle, with its head planted firmly in a flower. The Kaufman guide describes it an autumn insect that is common on "goldenrods and thoroughworts," but in this case it is feeding on a mint plant. Like other soldier beetles, leatherwings rely primarily on nectar but also eat pest insects such as aphids.

As I was taking these photos, I was fascinated by the wasp-like stripes on the leatherwing's abdomen. So far I have not found an explanation for them.

In the photo above, the leatherwing is joined by a wasp, which I believe belongs to the genus Philanthus. Wasps in this genus are known as "beewolves" because they prey on other stinging insects. Female Philanthus wasps dig burrows and lay their eggs on paralyzed bees and wasps.

I have been somewhat surprised by just how popular these mint plants have proven among insects. I have seen many different species nectaring there. In addition to the two mentioned above, I have also seen honey bees, bumble bees, and at least one fly species. Today the mint flowers were full of wasps. Philanthus wasps were probably the most common, but I also saw a couple Eumenes fraternus wasps wasp-like thick-headed flies (see here), and at least one other species I couldn't identify. Members of the Eumenes genus often build mud nests to lay their eggs. Four Three wasps, including two Philanthus wasps, and one Eumenes fraternus (right) are shown in the photo below.

More photos of these insects at my Flickr account.

Friday, August 21, 2009

Loose Feathers #201

Blue Tit / Photo by Flickr user nagillum

Bird and birding news
Birds in the blogosphere
Environment and biodiversity
Carnivals and newsletters

Thursday, August 20, 2009

SkyWatch Friday: Route 1 Bridge

I am posting the image above as a contribution to this week's SkyWatch Friday. This is US 1 Bridge connecting New Brunswick and Edison. Northbound lanes are in the older, arched bridge, and southbound lanes are in the more modern structure. A few more sky photos are on my Flickr account.

For other contributors' photos, click the badge below.

I and the Bird

Liza Lee Miller has posted the 107th edition of I and the Bird #107.

Earth Not Cooling; Global Warming Still Happening

Apparently some climate change skeptics are using the relatively mild summer experienced by some parts of the US to push the notion that global warming has stopped and the earth is cooling. In their eyes, of course, this means there is no need for restrictions on carbon emissions or new efficiency standards. It would be comforting if this were the case, but the evidence does not support it.

According to data from the National Space Science and Technology Center in Huntsville, Ala., the global high temperature in 1998 was 0.76 degrees Celsius (1.37 degrees Fahrenheit) above the average for the previous 20 years.

So far this year, the high has been 0.42 degrees Celsius (0.76 degrees Fahrenheit), above the 20-year average, clearly cooler than before.

However, scientists say the skeptics' argument is misleading.

"It's entirely possible to have a period as long as a decade or two of cooling superimposed on the long-term warming trend," said David Easterling, chief of scientific services at NOAA's National Climatic Data Center in Asheville, N.C.

"These short term fluctuations are statistically insignificant (and) entirely due to natural internal variability," Easterling said in an essay published in the journal Geophysical Research Letters in April. "It's easy to 'cherry pick' a period to reinforce a point of view."

Climate experts say the 1998 record was partly caused by El Nino, a periodic warming of tropical Pacific Ocean waters that affects the climate worldwide.
Indeed, El Nino has returned this year, and already we are starting to see some record or near-record temperatures. Global ocean surface temperatures were the hottest on record in June and in July. This year has also featured the second hottest global mean temperature for July. Clearly some of this is being caused by El Nino, just like the record temperatures of 1998, but it seems premature to declare that we are entering a global cooling phase at the same time as the oceans are hitting record temperatures.

The cooling argument largely rests on isolating the years since 1998, as in the following graph from the McClatchy article linked above:

It is true that global average temperatures have failed to match those of 1998 in the years since. In fact, they have generally stayed at least three tenths of a degree below the 1998 average high. Yet even within this cherry-picked decade, there appears to be a subtle upward trend, if one ignores the extreme high of 1998 and the extreme lows of 2000 and 2008, and several of those years rank just below 1998 on a list of hottest years.

If you extend the timeline back further, as in the graph above from FiveThirtyEight, the temperatures from the past decade do not seem like evidence of cooling. Instead they seem right in line with the long term warming trend.

Wednesday, August 19, 2009

Vulnerable Species Under Review for Endangered Species Listing

Yesterday the US Fish and Wildlife Service announced that it would review the status of 29 vulnerable species for listing under the Endangered Species Act. No birds are on this review list, so the results will not directly affect birders. Instead, there are twenty plants, two fish, one insect, and six snails. Here is a list of the species under consideration:

The 20 plants for which the service issued a positive finding are: Yellowstone sand verbena, Ross’ bentgrass, Hamilton milkvetch, Isely milkvetch, skiff milkvetch, precocious milkvetch, Cisco milkvetch, Schmoll milkvetch, Fremont County rockcress, boat-shaped bugseed, Pipe Springs cryptantha, Weber whitlowgrass, Brandegee’s wild buckwheat, Frisco buckwheat, Ostler’s peppergrass, Lesquerella navajoensis (a bladderpod), Flowers’ penstemon, Gibben’s beardtongue, pale blue-eyed grass and Frisco clover.

The fish is the northern leatherside chub, the two insects are the Platte River caddisfly and mist forestfly (or meltwater lednian stonefly).

The six snails are the frigid ambersnail, Bearmouth mountainsnail, Byrne Resort mountainsnail, longitudinal gland pyrg, Hamlin Valley pyrg and sub-globose snake pyrg.
In most cases loss of habitat is the primary issue, but climate change is cited as a contributing factor for several species. I have not yet seen a communication directly from the USFWS on this announcement, so I am not sure of the background for all of the species.

Unfortunately the announcement was a case of some steps forward, other steps back, as the USFWS also rejected petitions for nine species, one of which was the Ashy Storm-Petrel. The agency explains its reasoning; the petitioner (the Center for Biological Diversity) critiques the decision.

Brazilian Merganser. Credit: Bird Life InternationalIn other endangered species news, last week I missed an announcement that the USFWS is proposing to list seven Brazilian bird species as endangered.
Addition of a foreign species to the federal list of threatened and endangered species places restrictions on the importation of either the animal or its parts. Listing also serves to heighten awareness of the importance of conserving these species among foreign governments, conservation organizations and the public.

The seven species are all native to the Atlantic Forest and neighboring regions of southeastern Brazil and include the black-hooded antwren, Brazilian merganser, cherry-throated tanager, fringe-backed fire-eye, Kaempfer’s tody-tyrant, Margaretta’s hermit, and southeastern rufous-vented ground-cuckoo.
The agency is seeking comments on the proposed regulation, which can be submitted at for the next 60 days.

Tuesday, August 18, 2009

Too Much Cash for Clunkers?

One complaint about the Cash for Clunkers program, in which the government subsidizes new auto purchases for car owners with inefficient vehicles, is that it costs too much. A recent report supports that conclusion:

While carbon credits are projected to sell in the U.S. for about $28 per ton (today's price in Europe was $20), even the best-case calculation of the cost of the clunkers rebate is $237 per ton, said UC Davis transportation economist Christopher Knittel.

"When burned, a gallon of gasoline creates roughly 20 pounds of carbon dioxide. I combined that known value with an average rebate of $4,200 and a range of assumptions about the fuel economy of the new vehicles purchased and how long the clunkers would have been on the road if not for the program," Knittel said. "I even assumed drivers didn't change their habits, although some analysts have suggested that the owners of new vehicles will drive more than they would have with their old cars.

"In the end, the lowest cost to remove one ton of carbon from the environment was $237. More likely scenarios produced a cost of more than $500 per ton, even when we accounted for reductions in pollutants other than greenhouse gases. That suggests the Cash for Clunkers program is an expensive way to reduce carbon."
As climate change policies go, there are definitely better ways to spend money. However, reducing emissions is not the only goal of the program. Economic stimulus and support for the domestic auto industry were probably as important as efficiency when the bill was formulated. The stimulus portion seems to be working to some degree since the program is already out of money; support for domestic workers may be harder to measure. An analysis of whether this particular plan has been worth the cost ought to take those goals into consideration. It may still be a case of overspending, but perhaps not by quite as much.

Monday, August 17, 2009

Stolen Bird Skins

Bird skins similar to those stolen
Photograph by the Natural History Museum

Over the weekend I read a disturbing story in The Guardian about a theft of bird skins from the Natural History Museum's ornithological collection at Tring (U.K.).
Curators at the museum's bird collection in Tring, Hertfordshire, noticed that dozens of specimens had gone missing following a break-in on 24 June.

Although the thieves left behind more than 8,000 "specimen types", including the finches collected by Charles Darwin in the Galápagos, they took 299 birds.

The gang, which could have stolen the birds to order, removed quetzal and cotinga birds, animals that had originated in Central and South America, and birds of paradise from Papua New Guinea.

Police believe those responsible had detailed knowledge of the birds since the cabinets were labelled with Latin names organised in evolutionary order and only a small number of birds were disturbed.
Why would someone steal bird skins? The police and curators think that the colorful feathers may be sold as raw material for clothing or fishing lures. They could also end up in the hands of private collectors.

Large museum collections of bird skins may seem like an anachronism since so much research today is done through observation of live birds. Shooting birds is no longer necessary to determine an identification. However, they continue to serve an important role for research and education. Field guides depend at least in part on the study of museum specimens. Thus the theft of such rare specimens is a real loss. The best outcome would be if the skins were found intact.

Sunday, August 16, 2009

A Purple Box

The box shown above is one of several such purple boxes hung from trees around Hacklebarney State Park, near Chester, New Jersey. The boxes are part of a USDA survey for Emerald Ash Borers. These beetles are not originally from North America; instead, they arrived from eastern Asia sometime prior to 2002, when the first specimens were discovered in the Detroit area. Since then it has spread to 10 states in the Midwest and Mid-Atlantic regions.

This species poses a serious threat to native ash trees, potentially rivaling the destruction caused by Chestnut blight and Dutch elm disease in the last century. The USDA website on the emerald ash borer describes their potential impact:

Emerald ash borer is a serious pest and quarantines are established around infestations. Larvae feed in the phloem and outer sapwood producing galleries that eventually girdle and kill the tree. This invasive pest has had a devastating impact on communities that now face significant tree removal costs associated with dead or dying ash trees that pose a threat to public safety.

Ash trees are as important ecologically in the forests of the northeastern United States and eastern Canada, as they are economically. Ash trees fill gaps in the forest and provide shade for the forest floor. They are very desirable for urban tree planting because they grow well under difficult conditions. Ash wood is valued for flooring, furniture, sports equipment (e.g., baseball bats, hockey sticks, oars), tool handles, and supplies for dairies, poultry operations and beekeepers.

Other repercussions include decreased property values, losses in the long-term supply of ash wood, decreased air quality, increased electricity use during hot weather, and negative impacts on Native American cultures that use ash wood for traditional crafts and ceremonies. In addition, there are other detrimental impacts on wildlife and natural ecosystems. As a vital component of forest succession, ash colonizes and stabilizes disturbed areas. In addition, ash is one of the few native trees able to out-compete weeds that prevent most other species from becoming established.
The USDA has posted images of the borers and some signs of infestation.

The potential destructiveness of emerald ash borers is a reminder that we need to be careful about what sorts of plants, insects, and other creatures are introduced to the continent. Unfortunately this is difficult in an era of widespread globalized trade and international travel. It is all to easy for a species to be introduced, either accidentally or deliberately.

Saturday, August 15, 2009

Purple Loosestrife and its Visitors

The photo above shows a cluster of Purple Loosestrife (Lythrum salicaria). This flower is native to Eurasia but was introduced to this continent in the 19th century. It has since spread through most of the United States and Canada. While its racemes of purple flowers, this plant's tendency to crowd out native wildflowers has landed it on least wanted lists. It is common in wetlands and along highways and waste areas.

This particular cluster, a large, dense mix of loosestrife and Phragmites australis, seems quite attractive to a variety of insects. (No doubt this attractiveness had aided its spread.) I have included photographs of several below.

First up is a Silver-spotted Skipper (Epargyreus clarus), a species mentioned in a previous post.

Next is what I believe to be a Crossline Skipper (Polites origenes). This was a challenging identification because I only have a shot of the undersides of this butterfly's wings, but it seems to be the best match among species that might be flying now.

Photographing the skippers was somewhat difficult since many of them showed little inclination to sit for long on a single raceme. I caught this Hobomok Skipper (Poanes hobomok) just as it was taking off. (The closely-related Zabulon Skipper was featured in a previous post.) In addition to the butterflies shown above, there were many European Skippers (Thymelicus lineola), as well as a few Orange Sulphurs (Colias eurytheme), Cabbage Whites (Pieris rapae), and Eastern Tiger Swallowtails (Papilio glaucus), none of which I managed to photograph.

The cluster also attracts other insects, such as the wasp above. Wasps are still somewhat beyond my identification skills, so I cannot put a name on it at present. The closest I can find is the subfamily Eumeninae, which includes potter and mason wasps. These are mostly solitary wasps that feed on nectar and kill various insects to feed their larvae. If anyone has a better identification, please leave a comment.

Included in this week's SkyWatch Friday:

Friday, August 14, 2009

Loose Feathers #200

Wilson's Warbler / Photo by Donna Dewhurst (USFWS)

Birds and birding news
Birds in the blogosphere
Environment and biodiversity
Carnivals and newsletters

Wednesday, August 12, 2009

Back From the Dead

The Tasman Booby was long thought to be extinct. Polynesian settlers wiped out much of its population in the 13th century, and what was known to remain of its population was hunted to extinction by European sailors in the 18th century. Both sets of hunters considered the booby a valuable food source. As it turns out, this species was not actually extinct. However, they did not survive as a small remnant population but as a subspecies of the Masked Booby.

Researchers had long suspected that the "extinct" Tasman booby and the living masked booby of the North Tasman Sea were closely related. The birds have similar male and female body shapes and characteristically long wings, for starters.

But it was only when a group of naturalists, paleontologists, and geneticists pooled their expertise that these suspicions could be put to the test, said Tammy Steeves of the University of Canterbury in New Zealand, who led the new study.

The researchers compared fossilized and modern bones and DNA from specimens identified as Tasman and masked boobies.

Physically, the fossil bones looked strikingly similar to their modern counterparts. More important, the DNA was a perfect match, Steeves said.
According to the article, the two were initially classified as separate species because palaeontologists compared bones of female Tasman Boobies with male Masked Boobies. The significant size difference between the sexes made the two populations appear to be separate species.

Tuesday, August 11, 2009

Bird Nests from Cape May County

In keeping with the nest theme from yesterday's post, here are a few nests that I encountered recently. The first is the nest of a Marsh Wren pair at Stimpson Island Road in Cape May County. That road runs out through fields into a salt marsh; at the end of the road you can look out over acres of marsh and follow a few short trails. All around the parking lot there were singing Marsh Wrens, and a few of their nests were openly visible.

Like other wren species, Marsh Wrens often build dummy nests. A male will start construction of several and then his mate will finish the job on one of them. A pair will often raise two or three broods per season. It was not clear if this nest was currently active, no longer being used, or just a dummy.

The second nest was one that I found at Beaver Swamp WMA. This one was about four feet off the ground in a small bush. The nest is about five inches wide, and it contained two eggs, each about an inch long.

No birds were visible either in or around the nest, and I could not hear any scolding coming from nearby bushes. So I think that this nest was probably abandoned after these two eggs failed to hatch. Based on the size of the nest, its location, and the appearance of the two eggs, I think that this nest probably belonged to a pair of Northern Cardinals. Usually cardinals lay 3-4 eggs, so it is possible that there were other eggs that either hatched or got carried off by a predator.

Finally, I may have posted both of these already, but here are two osprey nests. The first is at Brigantine.

The second is in Cape May Harbor.

A useful guide for identifying nests and eggs is A Guide to the Nests, Eggs, and Nestlings of North American Birds by Paul Baicich and Colin Harrison. The egg illustrations in that guide were very helpful in identifying the nest from Beaver Swamp. Of course, other guides are available as well.

Monday, August 10, 2009

Warblers in Boxes

When I think of southern swamps, there are a few bird species that come to mind – Pileated Woodpecker, Red-shouldered Hawk, Barred Owl, Northern Parula. But none is more closely associated in my mind with southern wetlands than the Prothonotary Warbler. The ringing songs of these bright yellow birds are a prominent feature of spring and summer mornings in wetlands from Maryland southward.

Prothonotary Warblers are one of only two North American wood warbler species to nest in cavities. (The other is Lucy's Warbler.) This imposes a natural restriction on nesting opportunities. Even where the habitat is right, the warblers must compete for nest sites not only against members of their own species but also against other cavity nesters like Tree Swallows and House Wrens, as well as introduced species like European Starlings. While it presents a challenge for nesting warblers, it also makes it possible for people to help the species directly by providing additional nesting boxes that meet their needs.

Volunteers in Virginia have been doing just that over the past few decades. Virginia is one of the few places where the Prothonotary Warbler's breeding population has been increasing, thanks to an active program of installing and maintaining nestboxes, coupled with the protection of appropriate habitat. There are currently about 500 artificial nest sites in eastern Virginia, and volunteers continue to add more.

This year, the attempt to add an additional 60 nest boxes to the Northwest River State Natural Area in Chesapeake ran into protests from a nearby landowner.

But Luton also made it clear he wanted no part of a scientific project next door at the Northwest River State Natural Area, where volunteers want to help revive populations of a small, yellow songbird - the prothonotary warbler - struggling against a tide of predators and vanishing habitat.

Speaking before the Virginia Marine Resources Commission, a state agency debating whether to allow construction of 60 bird boxes on the Chesapeake preserve, Luton said he feared the little bird might some day be declared an endangered species.

Citing its decline across most of the United States - except in Virginia, where numbers are increasing - Luton reasoned that the warblers could jump across Smith Creek and take up residence on his land, where federal endangered-species protections "could be a catastrophe."

"I'm fighting for my property," he told the commission.
Eventually the Virginia Marine Resources Commission decided to install 60 boxes on the preserve anyway, but not along the border of Luton's property. This course of action was probably the easiest way of continuing the important conservation program while minimizing conflict. However, the case raises some important questions. There are a lot of issues to unravel in this story, and I doubt that I will do any one of them justice in this short post. But here are a few problems that I see.

First, there is a certain incoherence in fearing that Prothonotary Warblers might be listed as a federally endangered species but obstructing actions that would prevent further decline. The best way to avoid any hardships that an endangered species listing might impose is to avoid having to list a species in the first place. In the case of the Prothonotary Warbler that means preserving southern wetland habitat and maintaining adequate nesting sites for a sustainable breeding population. One of the commissioners noted this when he issued the decision.
"I hear what you're saying, Mr. Luton," said commission Director Steve Bowman. "But it seems the more you have of them, the less likely they will be on the endangered list."
Second, I have to wonder just how likely the Prothonotary Warbler is to be listed, or at least to be listed any time soon. This species has experienced a substantial decline in recent decades, as much as 30-40% since 1966. This decline, while startling, is only enough to place the species with a yellow flag on the Audubon Watchlist and as a species of Least Concern on the IUCN Red List. There are many bird species that have suffered far worse declines over the same period.

As far as I can tell, Prothonotary Warbler is not currently a candidate for federal listing. This places it in line behind other candidates (such as the rufa subspecies of the Red Knot) that have suffered even more dramatic declines yet have languished on the candidate list for years without being given the full protections that come with listing under the Endangered Species Act. In part, this was a result of the Bush administration dragging its heels on species protections, but so far the Obama administration has not shown much interest in wildlife conservation, either. This makes me skeptical that the Prothonotary Warbler would suddenly be rushed through the system, especially since the organizations that might push their cause seem more concerned with species threatened by climate change right now.

In other words, Luton probably has little to fear in terms of the Prothonotary Warbler becoming an officially endangered species anytime soon. And even if it did, this would not necessarily mean restrictions on his property. Much would depend on whether they were breeding there, how much of his property was occupied, and other factors – all of which are hypothetical at the present time. In addition, one of the warbler's biggest problems is that its wintering range in Central America and the West Indies is under pressure because of the destruction of mangrove forests to make way for other uses. Any conservation strategy for these warblers needs to deal as much with that threat as with preservation of potential breeding grounds in the United States.

Third, there is the problem of the intrusion of private interests onto public property. Luton wanted to block a conservation program on state property on the basis of a hypothetical future presence of a hypothetically endangered species on his own private property. The species is not on his property now, and we cannot be certain that any future presence of the species there would be caused by the nestbox program. The implication in all this is that the concerns of private landowners should trump the legitimate management decisions made by public officials, even when the harm claimed by the landowner only involves some possible future land use, not current conditions. In my opinion this sets a bad precedent for future wildlife management on public land.

Fourth, even on private land, property rights are not absolute. Landowners are not free to develop their properties as they see fit. Instead they must comply with a variety of laws from zoning regulations to fire codes to noise and nuisance ordinances. If a property is needed for a project that benefits the public, it can be seized (with compensation) through eminent domain. Endangered species protections are simply one set of regulations among many and not inherently more onerous than restrictions on building height or requirements for off-street parking. Compliance with such regulations costs money and limits how a property might be used, yet they are subject to far less opposition and paranoia than endangered species (and other environmental) protections.

The good news is that the nestbox project will continue, at least for this year, despite Luton's opposition. It has been very successful; this year alone 108 nestlings were banded in the 38 boxes at Northwest River Park, near the preserve in question. The program's success makes me think that other states within the Prothonotary Warbler's range would do well to follow Virginia's example and implement nestbox programs if they have not done so already.

(Top photo by; second photo by Robert Mussey. Thanks to long-time reader Peter Doherty for alerting me to this article.)

Sunday, August 09, 2009

Zabulon Skipper

This Zabulon Skipper was in the yard today and sat cooperatively while I took a series of photos of it. This skipper is common and widespread in the eastern United States, especially in late summer. I find it more easily identifiable than most other grass skippers.

The plain yellow upperside of the hindwing is field mark of this species, as is the pale spot near the base of the hindwing on the underside.

Sometimes it sits with its wings folded, and other times it adopts the jet plane posture.

Saturday, August 08, 2009

Silver-spotted Skipper

In a previous post, I mentioned having trouble getting a Silver-spotted Skipper to sit still long enough for me to take a photograph of it. A couple days ago, I found a more cooperative individual and took a few pictures. This one was feeding on a Buddleia, or butterfly bush.

Silver-spotted Skippers belong to the spread-wing skippers (subfamily Pyrginae). The species is widespread and common across much of North America. Unlike most other skippers (the "little brown jobs" among butterflies), this species is easily identifiable for the irregular white patch on its hindwing.

Friday, August 07, 2009

Loose Feathers #199

Bird and birding news
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Thursday, August 06, 2009

SkyWatch Friday on Thursday: Cape May Meadows

On Sunday night there was a gorgeous sunset over the Nature Conservancy's bird refuge at the South Cape May Meadows. The refuge gate closes at dusk, but if you stay too late, motion sensors will let you out.