To see if ravens communicated using gestures, scientists investigated wild ravens in Cumberland Wildpark in GrĂ¼nau, Austria. Each bird was individually tagged to help identify them.Apparently, the ability to use gestures for communication is a trait rarely found outside of primates like humans and chimpanzees. It has been recorded among dogs that have been trained by humans, but not among other animals in the wild.
The researchers saw the ravens use their beaks much like hands to show and offer items such as moss, stones and twigs. These gestures were mostly aimed at members of the opposite sex and often led those gestured at to look at the objects. The ravens then interacted with each other — for example, by touching or clasping their bills together, or by manipulating the item together. As such, these gestures might be used to gauge the interest of a potential partner or strengthen an already existing bond.
"Most exciting is how a species, which does not represent the prototype of a 'gesturer' because it has wings instead of hands, a strong beak and can fly, makes use of very sophisticated nonvocal signals," Pika told LiveScience.
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Wednesday, November 30, 2011
Ravens Communicating by Gestures
A new study find that ravens can gesture with their wings or bills to point out objects.
Tuesday, November 29, 2011
Louisiana Whooping Cranes Not Doing Well
Whooping Crane / Photo by Ryan Hagerty (USFWS) |
Prior to February’s reintroduction, the last time a wild whooping crane was seen in Louisiana was in 1950. The conversion of marsh habitat to farmland, destructive hunting practices and other factors led to the bird’s disappearance from the region.Another 16 Whooping Cranes will be released at the same site in Louisiana next month. Hopefully this group will fare better.
But the Louisiana reintroduction has had strong backing from Salazar, U.S. President Barack Obama’s top conservation official, who described the whooping crane as “an iconic species” whose return to the state represented a “milestone moment” for international wildlife preservation.
The whooping crane’s population was down to just 22 in 1941, prompting a joint U.S.-Canada recovery effort that has become a global model for endangered-species conservation....
But the proposed Louisiana flock is considered crucial to eventually removing the species from North America’s endangered list because increasing the number of separate, self-sustaining populations — and diversifying the range of whooping crane habitats — is seen as the bird’s best defence against a catastrophic collapse from disease, an extreme weather event or other disasters.
Monday, November 28, 2011
Review: National Geographic Field Guide to the Birds of North America, Sixth Edition
The National Geographic Society has refreshed its venerable Field Guide to the Birds of North America with a new revised edition. This sixth edition comes with substantial updates and enters a field guide market crowded with some great field guides and many more good ones. In this review, I will focus on what is new in the sixth edition and how it compares to another guide with painted illustrations that covers the same area, The Sibley Guide to Birds.
What is new in the sixth edition? There are 23 new species, which brings the total species covered up to 990. Over 300 painted illustrations (about one tenth of the total) have been added or revised. Range maps are updated to include new data and display migration ranges in addition to the breeding and wintering ranges. There is also an appendix of maps showing the ranges of subspecies for birds that have multiple forms. (My understanding is that both the migration ranges and subspecies maps are new for the sixth edition, but I do not have a copy of the fifth edition to check on this.) Taxonomy is also updated to reflect changes in the AOU Checklist through summer 2011. In the case of wood warblers, the scientific names are updated, but the ordering of species is not.* (I imagine it was easier to alter the text of the species accounts at the last minute than it would have been to reorder the illustration plates.) The plates were redesigned to make the illustrations less crowded, though to my eye, some plates still look rather crowded (especially among gulls and terns).
In comparison to The Sibley Guide, birds are posed more naturally, in the ways in which you might see them in the wild. Birds in the National Geographic guide look more lifelike, for the most part, and their colors seem more true to nature. Many birds are presented in a 3/4 view that shows the breast or back more clearly than in The Sibley Guide. Its smaller size makes it more portable than Sibley's guide for North America (though it is slightly larger than Sibley's regional guides). Despite its smaller size, the National Geographic guide manages to include more descriptive text per species.
The Sibley Guide retains some advantages of its own. Birds are posed more consistently so that you see each species from the same angles as related species, with which they are most likely to be confused. Sibley painted flight illustrations for every bird in the guide; this can make a difference for some situations. In some cases (like Redhead vs. Canvasback), Sibley does a better job of showing differences in shape. I also much prefer Sibley's illustrations of sparrows to those in the National Geographic guide.
The look and feel of this guide is very similar to Svensson et al.'s Birds of Europe, though it lacks some of the instructive text that makes that guide stand apart. I know some birders who still swore by older versions of the National Geographic guide long after the Sibley guide came out. After spending some time with this guide, I can see why. This is a fine resource to use as a primary field guide, particularly if you want one that covers all of North America. I could also see it being useful on cross-country trips, especially to areas where both eastern and western birds are both routine. Birders will probably want to have both National Geographic's Field Guide to the Birds of North America and The Sibley Guide to Birds on their bookshelves.
This review is based on a copy provided to me by the publisher. The field guide is supplemented by an online birding site.
* That said, the Cerulean Warbler is referred to as Setophaga cerulea in the species account and Dendroica cerulea in the introduction.
What is new in the sixth edition? There are 23 new species, which brings the total species covered up to 990. Over 300 painted illustrations (about one tenth of the total) have been added or revised. Range maps are updated to include new data and display migration ranges in addition to the breeding and wintering ranges. There is also an appendix of maps showing the ranges of subspecies for birds that have multiple forms. (My understanding is that both the migration ranges and subspecies maps are new for the sixth edition, but I do not have a copy of the fifth edition to check on this.) Taxonomy is also updated to reflect changes in the AOU Checklist through summer 2011. In the case of wood warblers, the scientific names are updated, but the ordering of species is not.* (I imagine it was easier to alter the text of the species accounts at the last minute than it would have been to reorder the illustration plates.) The plates were redesigned to make the illustrations less crowded, though to my eye, some plates still look rather crowded (especially among gulls and terns).
Harlequin Ducks from Field Guide to the Birds of North America |
The Sibley Guide retains some advantages of its own. Birds are posed more consistently so that you see each species from the same angles as related species, with which they are most likely to be confused. Sibley painted flight illustrations for every bird in the guide; this can make a difference for some situations. In some cases (like Redhead vs. Canvasback), Sibley does a better job of showing differences in shape. I also much prefer Sibley's illustrations of sparrows to those in the National Geographic guide.
Pink-footed Goose from Field Guide to the Birds of North America |
This review is based on a copy provided to me by the publisher. The field guide is supplemented by an online birding site.
* That said, the Cerulean Warbler is referred to as Setophaga cerulea in the species account and Dendroica cerulea in the introduction.
Sunday, November 27, 2011
November Berries
Fruit-bearing trees and shrubs help many bird species make it through our cold northern winters. Here are a few plants that are still bearing berries near the end of November. All of these photos were taken in the past few days. Above is a very familiar tree, American Holly.
This is a Winterberry shrub, which loses all of its leaves in the fall but retains its berries through much of the winter. The shape of this individual plant suggested that it was a cultivar, though I do not know which, if any, it would be. I have never observed birds eating Winterberry fruits, but something must eat them as their fruit disappears gradually over the course of the winter.
Above are some rose hips from a Multiflora Rose shrub. Birds will eat these, sometimes in preference to berries from native shrubs. Multiflora rose is very invasive and may take over old fields if it is not kept in check.
Indian Coralberry is a native fruit-bearing shrub.
Most of the crabapples have been eaten already, mostly by European Starlings and American Robins, but a few are still lingering on the branches. Some of the remaining ones are starting to shrivel.
Not all fruit-bearing shrubs and trees still have their fruit. This Arrowwood Viburnum has been stripped bare of berries, leaving only empty fruit clusters behind.
This is a Winterberry shrub, which loses all of its leaves in the fall but retains its berries through much of the winter. The shape of this individual plant suggested that it was a cultivar, though I do not know which, if any, it would be. I have never observed birds eating Winterberry fruits, but something must eat them as their fruit disappears gradually over the course of the winter.
Above are some rose hips from a Multiflora Rose shrub. Birds will eat these, sometimes in preference to berries from native shrubs. Multiflora rose is very invasive and may take over old fields if it is not kept in check.
Indian Coralberry is a native fruit-bearing shrub.
Most of the crabapples have been eaten already, mostly by European Starlings and American Robins, but a few are still lingering on the branches. Some of the remaining ones are starting to shrivel.
Not all fruit-bearing shrubs and trees still have their fruit. This Arrowwood Viburnum has been stripped bare of berries, leaving only empty fruit clusters behind.
Saturday, November 26, 2011
Great-Looking Maybe, But Not With These Birds
Life is running a gallery of "Great-Looking Gifts" on their website, and the glass bird feeder shown above is one of them. Here is what they say about it:
Beyond that, I am not sure how functional this feeder would be in practice. The bowl seems very shallow and would not hold a lot of seed, so it would need constant refilling. If it swings back and forth, a lot of that seed could get knocked out. I can also imagine squirrels jumping on the feeder and either knocking it down or knocking the seed out. So if you are looking to splurge on a new bird feeder, I would suggest passing on this and looking for something more functional.
The one thing aquariums have over birdhouses is that you get to watch your fish whenever you want. Now birdhouses get their own high-visibility makeover: This sculptural Mod Glass birdfeeder has an appealingly spare, modern feel — and allows you to observe your colorful feathered friends as they're nibbling. ($78, apartment48.com)When I saw this image, the first thing that struck me was what birds they chose. The bird inside the feeder is a Common Redpoll, which breeds in the Arctic and migrates to southern Canada and the northern United States for the winter. The blue bird on the right is an Indigo Bunting, which breeds across the eastern United States and southern Canada and migrates south to Central America and the Caribbean for the winter. As far as I can tell, their breeding ranges do not overlap. These are two species that you are highly unlikely to see at the same feeder at the same time. The birds are also out of scale with each other, which makes the Photoshopping more obvious. Indigo Buntings are slightly larger than Common Redpolls but not twice their size, as this bunting appears to be.
Beyond that, I am not sure how functional this feeder would be in practice. The bowl seems very shallow and would not hold a lot of seed, so it would need constant refilling. If it swings back and forth, a lot of that seed could get knocked out. I can also imagine squirrels jumping on the feeder and either knocking it down or knocking the seed out. So if you are looking to splurge on a new bird feeder, I would suggest passing on this and looking for something more functional.
Friday, November 25, 2011
Loose Feathers #318
California Condors in flight above Bitter Creek NWR in California / Photo by Scott Flaherty (USFWS) |
- European researchers have found that the warming climate has slowed migration. In Finland, waterfowl are migrating up to a month later than they did 30 years ago. Researchers in the U.K. found that many migrants are not flying as far south as they used to.
- A few conservation websites featured Mexico's lesser-known turkey, the Ocellated Turkey in honor of Thanksgiving week. Here is one from Mongabay.com and another from the American Bird Conservancy.
- LiveScience interviews the scientist who discovered that Anna's Hummingbirds chirp with their tail feathers rather than their mouths during courtship display flights.
- A study finds that European Starlings learn patterns of food availability quickly but have trouble recognizing a slightly different pattern.
- Conservationists are trying to discourage Oregon residents from feeding pelicans along the coast.
- Despite conservation efforts populations of the endangered Florida Scrub-Jay have fallen by 25% in managed areas and up to 35-40% in the rest of Florida.
- Living Alongside Wildlife: This Thanksgiving, Don’t be a Hog (Nosed Snake)
- Laelaps: Alabama’s Wealth of Fossil Dinosaur Feathers
- Not Exactly Rocket Science: Microraptor – the four-winged dinosaur that ate birds
- Bourbon, Bastards and Birds: Secret Hooded Merganser Courtship Grounds
- Tails of Birding: Owl - Omen of Evil
- ABA Blog: I Don't Know
- Coyote Crossing: Energy waste as seen by the International Space Station
- Coffee and Conservation: Know your coffee birds: Scarlet Tanager
- A study on ecotourism found no detrimental effect from ecotourism on wild mammal populations and suggested that ecotourism could help conservation by providing an economic incentive to preserve areas along rivers, which tend to be under pressure from human settlements.
- A federal appeals court restored Endangered Species Act protections for grizzly bears around Yellowstone National Park.
- The American Museum of Natural History discovered 11 new sweat bee species, including five from New York City and its suburbs, which are published in the journal Zootaxa. The five New York bees are Lasioglossum gotham, found at the New York Botanical Garden and Brooklyn Botanical garden; L. ascheri, from Westchester and Suffolk counties; L. katherinae, from Brooklyn and Nassau County; L. rozeni, from Suffolk County; and L. georgeickworti, from Queens and Nassau and Suffolk counties.
- A newly-discovered orchid from Papua New Guinea is the only species of orchid known to flower only at night.
Thursday, November 24, 2011
Sweetgum in Autumn
This Sweetgum tree stayed green and turned fairly late this fall. When the tree has its leaves, it is easily recognizable by its five-pointed leaves, which are green in summer and turn yellow or red in autumn. In winter its bare branches form a conical shape.
In autumn, Sweetgum trees produce distinctive spiky seed balls. Right now, the seed balls are still mostly green. Over the next month or so, they will turn brown and fall. After they open, they will look something like the seed balls in this photo.
In autumn, Sweetgum trees produce distinctive spiky seed balls. Right now, the seed balls are still mostly green. Over the next month or so, they will turn brown and fall. After they open, they will look something like the seed balls in this photo.
Wednesday, November 23, 2011
Tuesday, November 22, 2011
Azaleas in Autumn
Azaleas are better known for their colorful flowers in the spring, but in the fall they produce some lovely colors, too. Here are two separate azalea shrubs, one with yellow leaves and the other with red leaves.
For good measure, below is a rhododendron bud, with yellow azalea leaves in the background.
For good measure, below is a rhododendron bud, with yellow azalea leaves in the background.
Monday, November 21, 2011
Salton Sea's Future in Doubt
Salton Sea in California is well known among birders for its breeding populations of waterbird species and the migratory birds each year. Because of changes in the amount of water runoff to the sea, its future as bird habitat is in question. The sea is rapidly evaporating, and its edges are turning into dusty flats. This situation is likely to get worse in the future without active intervention.
With evaporation outpacing incoming agricultural runoff, a thin sheet of water less than an inch deep and 100 yards wide on the east side of the sea's Mullet Island is all that protects tens of thousands of breeding and roosting cormorants, pelicans and herons from coyotes and raccoons....There is currently a lawsuit underway that seeks to remedy some of the problems that were not addressed in a water deal from 2003 that affects the status of the Salton Sea.
Environmental conditions are expected to get much worse in a few years at the Salton Sea, a non-draining body of water with no ability to cleanse itself. The sea was created in 1905, when the Colorado River broke through a silt-laden canal and roared unimpeded for two years into the Salton Sink.
Irrigation runoff traditionally helped stabilize the salinity of the sea, and enabled fish to thrive and make the region a haven for tens of thousands of birds and migratory waterfowl, including endangered species such as peregrine falcons, bald eagles, Yuma clapper rails and pelicans.
As it stands, salinity levels at the Salton Sea are about 50,000 parts per million parts of water, authorities said. By comparison, the salinity level of the Pacific Ocean is about 35,000 ppm.
Long-predicted catastrophic changes may begin to unfold in 2017, after an abrupt decrease in the amount of water flowing to the Salton Sea....
The surface will drop about 20 feet by 2030, Cohen said, shrinking the sea's volume by more than 60% and tripling its salinity. The effects will include the loss of fish and the tens of thousands of birds that eat them. The birds that remain will suffer from disease and reproductive deformities.
Sunday, November 20, 2011
Birds along the Canal
Yesterday morning I walked a segment of the Delaware and Raritan Canal upstream from the access point at Griggstown Causeway. The woods along the towpath were very birdy, though most of them were common species. White-throated Sparrows seemed to be in every shrub or tangle of vines. A Hermit Thrush was with one of the sparrow flocks. Several groups of Carolina Chickadees and Tufted Titmice roamed around, but they did not seem to have any less common birds flocking with them. At one point, I heard some Eastern Bluebirds calling, but I could not track them down. Near the spillway where I turned around, I spotted a flock of 20 or so Rusty Blackbirds. They were foraging in the woods along a creek and were moving around pretty actively. These birds are, sadly, harder to find than they used to be, so I enjoy any chance I get to see them.
Saturday, November 19, 2011
Killing Songbirds for European Cuisine
In yesterday's Loose Feathers, I linked to a report on an incident in which Hungarian officials seized a shipment of about 10,000 illegally-killed songbirds. The dead songbirds were most likely headed for restaurants in northern Italy. Traffic in wild songbirds is unfortunately routine in Europe, even though it is officially illegal in most of the EU. The most famous of the trafficked songbirds is probably the endangered Ortolan Bunting, part of Francois Mitterrand's last meal. However, many other species are also involved. Conservation organizations in Europe are doing their best to curtail the trade in songbirds, with mixed success so far.
Cyprus has been a center of songbird trapping, particularly during migration seasons when many birds are passing through the island on their way to and from mainland Europe. This fall almost 867,000 birds had been killed by mid-October.
Bee-eater / Photo credit: BirdLife Cyprus |
The toll is estimated on the basis of field data from BirdLife’s ongoing field monitoring of trapping activity with mist nets and limesticks, part of a systematic surveillance programme. This latest estimate – 866,905 birds- represents the number of birds killed between Thursday 1st September and Sunday 9th October 2011. The trappers are after Blackcaps and other songbirds, which will end up as illegal, and expensive, ambelopoulia delicacies served up in law-breaking restaurants, allowing the trappers to make huge profits. The first estimate for the autumn 2011 season, posted on September 12th, was for almost 90,000 birds, but trapping has gained pace since then. The estimate will be updated every Monday until the end of October.BirdLife Cyprus is asking birdwatchers and other wildlife lovers to sign an online petition asking the government of Cyprus to intervene. So far over 15,000 people have signed.
Friday, November 18, 2011
Loose Feathers #317
Rufous Hummingbird / Photo by Roy W. Lowe (USFWS) |
- Mating for life appears to reduce stress levels in Greylag Geese, particularly during fights, when males who have a partner nearby have lower heart rates than males without a partner.
- Hungarian officials recently seized a shipment of illegally-killed songbirds that was probably headed for restaurants in northern Italy. The birds included Eurasian Skylarks, Calandra Larks, Red-throated Pipits, Bluethroats, European Goldfinches, Fieldfares, Mistle Thrushes, Reed Buntings, and White Wagtails.
- Thirteen endangered Spoon-billed Sandpipers arrived in the U.K. to serve as a base population for a captive breeding program. Conservationists hope to use captive breeding to supplement the declining wild population.
- Thanks to a nestling monitoring program, 20 Scarlet Macaw fledglings took flight this year in Guatemala. Conservationists check nests and remove and hand-rear weak chicks to improve their chances for survival.
- The American Bird Conservancy has published a booklet on designing buildings to prevent bird kills.
- A scientist writes about studying Elegant Quail in Mexico.
- Central Park launched a website about eight penguin chicks being reared at the Central Park Zoo. The site includes video of the chicks.
- Maniraptora: Bird-friendly California vineyards may have fewer pests
- 10,000 Birds: Why do birds living near Chernobyl have smaller brains?
- The Birdist: Birds at Large: The Big Bang Theory
- The Brownstone Birding Blog: Keys To Proper Misidentification Of Birds
- Bird Light Wind: SF Bird Encounters – The Mural; The Making of a Mural (part 1); Part 2; Part 3
- Birding Is Fun!: Bird Hygiene
- Snail's Tales: Jaws of a different kind
- BugBlog: How to get a snail to go aaaaah!
- Bug Eric: Wasp Wednesday: Anacrabro ocellatus
- Pixiq: Animal Group Portraits
- The Freiday Bird Blog: Birds and Habitat: Cox Hall Creek WMA
- Exploration for oil and natural gas in the Arctic assists predators and scavengers while hurting ground-nesting birds. The link has a gallery of some of the winners and losers.
- Despite what some politicians say, the Regional Greenhouse Gas Initiative has been a success so far.
- The Atlantic State Marine Fisheries Commission is reducing the allowable catch of menhaden by 37%. Menhaden is used for such things as livestock feed, fertilizer, pet food, and fish oil, but is also an important prey species for many species of larger fish, seabirds, and marine mammals.
- Scientists studying fossil moths from 47 million years ago found that some of them had brightly-colored wing patterns, which suggests that they were active during the day.
- Camera traps found five wild cat species, including one that is critically endangered, in a Sumatran forest that is threatened by logging.
- An oil well off the coast of Brazil is leaking oil. Chevron claims to have the spill under control.
- TransCanada is exploring alternative routes for the Keystone XL pipeline that would avoid an environmentally sensitive region of Nebraska. One option is to reverse the flow of the existing Seaway Crude Pipeline, which has not been used much in recent years.
- A new study considers the ways in which New York state might be affected by climate change. Among other things, the Finger Lakes region will become hospitable to vineyards, while coastal communities will be susceptible to rising sea levels.
- Spiders.us is a new website for spider identification.
Thursday, November 17, 2011
Chipped Bark
While I was at Scherman Hoffman Wildlife Refuge on Saturday, I cam across a tree that had obvious damage to its trunk. A large section of bark was stripped away, and the wood underneath was chipped in a square-edged pattern. I was curious what would cause this pattern. The damage was too high to be the work of beavers. It is about the right height for deer, but would deer chew the wood underneath as well? Could a person have done this? The same pattern was not evident on nearby trees, so whatever did the damage was attracted to this particular tree.
Wednesday, November 16, 2011
Blueberry Leaves
At this point in the fall, the most colorful trees and shrubs that still have leaves tend to be introduced exotics like Norway Maple, Japanese Maple, and Winged Euonymus. One native shrub that still has colorful leaves is highbush blueberry. Fruits of this species are an important source of food for birds and other wildlife in early fall. By this point, any fruit is long gone, and the leaves have turned deep red.
Tuesday, November 15, 2011
Dried Goldenrod
After goldenrods bloom, they dry out and produce fuzzy clumps of seeds along the flower stems. The individual seeds are small and have silky parachutes attached so that the wind will disperse them. I think the plant above is one of the Tall Goldenrods I identified at the site of the former marina. Here is a photo of one in bloom from early October.
When I walked through the marina yesterday morning, I did not see or hear many birds at all (unlike last week). The most notable bird was an Osprey that flew back and forth along the river.
When I walked through the marina yesterday morning, I did not see or hear many birds at all (unlike last week). The most notable bird was an Osprey that flew back and forth along the river.
Monday, November 14, 2011
Animals Using Culverts to Cross Roads
Stone culvert / Photo by Wikipedia user Valerius Tygart |
Raccoons will use any kind but deer avoid culverts with cobbled floors and eastern gray squirrels don’t seem to like arch-shaped passages, the study’s lead author, ecologist J. Edward Gates, said Friday. Great blue herons prefer box-shaped culverts with sandy bottoms, the study found....The study was funded by the Maryland State Highway Administration to see if culverts could be used to provide wildlife with safer ways to cross roadways. Highways present a real barrier to large wildlife. If they choose to cross, they risk death or injury. If they choose not to cross, they lose access to the foraging habitat on the other side of the road as well as the opportunity to mate with members of their species that live on the other side. (The latter is especially a problem when endangered or declining species are involved; in the mountain west, wildlife bridges are being built over interstates to avoid genetic isolation.) For drivers, there is a risk of vehicle damage or injury when larger animals try to cross the road. Perhaps the solution to the problem is more or better culverts where roads can accommodate them.
Culverts are tunnels, usually made of concrete or metal, that allow water to flow beneath roadways. Animals moving along stream banks may naturally follow the water through culverts, Gates said.
Researchers documented 57 species using the conduits, including nesting barn swallows, feral cats and white-tailed deer — a species of particular concern because they cause dozens of deaths in collisions each year around the country....
The study found deer using tighter passageways than previously documented — as small as 3.2 feet high and 4.7 feet wide....
He said preferences for certain culvert shapes may have more to do with what’s on the tunnel floor. Many box-shaped culverts studied were made of concrete whereas the rounded conduits were all made of corrugated metal. The boxy shape preferred by herons also provides room to spread their wings and quickly escape, the study says.
Sunday, November 13, 2011
Winding Down
Yesterday I walked through Scherman Hoffman Wildlife Sanctuary to see what sort of birds were moving through. I followed the field loop trail and part of the dogwood trail, for those familiar with the preserve. Most of the trees were already bare, with most of the exceptions being beeches or oaks. The preserve looked so different from the last time I was there in late summer.
The trails were fairly quiet with only a few small flocks of birds being active. Most of them were common resident species, but Dark-eyed Juncos and Hermit Thrushes marked the onset of winter birding. A couple hawks passed overhead: a Red-tailed Hawk and a Cooper's Hawk. The constantly agitated behavior of the American Crow flocks suggested that there might be more raptors around than those two.
The exception to the small flocks rule were large roaming flocks of blackbirds. The biggest one I saw mostly consisted of Red-winged Blackbirds, maybe about 100 in all. Among them were a small number of Brown-headed Cowbirds and two Rusty Blackbirds. There were also Common Grackles in another flock.
Most of the plants in the meadows were dying back, with only the dried stalks still standing.
The trails were fairly quiet with only a few small flocks of birds being active. Most of them were common resident species, but Dark-eyed Juncos and Hermit Thrushes marked the onset of winter birding. A couple hawks passed overhead: a Red-tailed Hawk and a Cooper's Hawk. The constantly agitated behavior of the American Crow flocks suggested that there might be more raptors around than those two.
The exception to the small flocks rule were large roaming flocks of blackbirds. The biggest one I saw mostly consisted of Red-winged Blackbirds, maybe about 100 in all. Among them were a small number of Brown-headed Cowbirds and two Rusty Blackbirds. There were also Common Grackles in another flock.
Most of the plants in the meadows were dying back, with only the dried stalks still standing.
Saturday, November 12, 2011
Red Maple in Autumn
Red Maple is a common and widespread native hardwood tree. It grows across the eastern U.S. from southern Florida north to Newfoundland and from the Atlantic coast west past the Mississippi River. Red Maples are easily recognizable for their leaves with three main lobes and red leafstalks.
In autumn, the leaves turn red, sometimes very dark red, though some leaves may be orange or yellow.
Most of the Red Maples I see regularly are young trees, so they are still fairly short, like the one above.
However, Red Maples can grow to be 60 to 90 feet tall when they are mature, like this one, which I photographed against the sky.
In autumn, the leaves turn red, sometimes very dark red, though some leaves may be orange or yellow.
Most of the Red Maples I see regularly are young trees, so they are still fairly short, like the one above.
However, Red Maples can grow to be 60 to 90 feet tall when they are mature, like this one, which I photographed against the sky.
Friday, November 11, 2011
Loose Feathers #316
Snowy Plover / Photo by Keenan Adams (USFWS) |
- Almost 500 birds of 30 species were found dead at a wind farm in West Virginia in October. It appears that instead of colliding with wind turbines, they were attracted to the 250-watt floodlights at an electrical substation, where they either died from exhaustion or crashed into one of the substation's structures. The deaths happened during an overcast or foggy night, conditions when artificial lights are especially confusing to migratory birds.
- Anna's Hummingbirds are able to stay active in wet weather because they shake their heads and twist their bodies rapidly in flight to cast the water off their feathers. The link has a video of this behavior.
- Hawaii is becoming the planet's extinction capital as many of its endemic species are in serious decline or already extinct. Among the species is the 'Alala, or Hawaiian Crow, which is extinct in the wild but still has a captive breeding program that may some day result in reintroduction.
- The earthquake in Oklahoma stirred up a swarm of birds, bats, or insects that was dense enough to be visible on weather radar.
- An article on this year's Rio Grande Valley Birding Festival includes excerpts from an interview with Greg Miller, the birder portrayed by Jack Black in The Big Year.
- In summer, King Penguins at South Georgia Island bathe in streams and mud to keep from overheating.
- A same-sex pair of African Penguins at the Toronto Zoo is going to be separated in an attempt to get them to breed. The African Penguin population is declining in the wild, and the two male penguins were acquired by the zoo to participate in a captive breeding program.
- The Guardian has some suggestions about making a garden hospitable to wintering birds.
- Some vineyards in New Zealand have used live falcons to guard their grapes against songbird flocks that feed on them. A similar solution is being used at some vineyards in Sonoma County, California.
- 10,000 Birds: Tubenose Taxonomy 101
- Not Exactly Rocket Science: Cross-dressing raptors avoid violence
- Laelaps: Debating Diatryma
- Audubon Guides: Formerly Known As the Louisiana Heron
- The Skeptical Moth: Diversification of Moths with Teeth
- Compound Eye: Naskrecki’s “Relics” argues for a conservation ethic rooted in evolutionary history
- The Dragonfly Woman: The Long, Involved Process of Giant Water Bug Mating
- Lawyers, Guns and Money: Endangered Species and Environmental Leverage
- Martin's Moths: The village of Moth
- Facing political pressure from both sides, the Obama administration decided to delay a decision on the Keystone XL pipeline until after the 2012 elections. Environmentalists were increasingly vocal in opposition to the proposed pipeline. In the most recent action, 12,000 protesters surrounded the White House to demand that the pipeline be stopped. Yesterday's announcement came on the heels of a decision by the State Department to investigate possible conflicts of interest.
- Meanwhile, the Interior Department will open new oil exploration in the Gulf of Mexico and off Alaska but keep the Atlantic and Pacific coasts of the U.S. off-limits to drilling.
- Even though the threat of climate change is well documented and some steps to reduce the threat are underway, global emissions of greenhouse gases continue to rise. Meanwhile, fossil fuel use is rising again in the United States as the economy slowly recovers from its deep recession.
- Spruces along the edge of the tundra are growing faster as the climate warms. The news for northern forests is not all good, however, as warmer temperatures also increases the threat of wildfires in interior forests.
- New research finds a decrease in the wintering population of Monarch butterflies in Mexico from 1994 to 2011. Habitat fragmentation in both breeding and wintering areas appears to be the major cause of their decline. This fall, drought in Texas and other southern states will pose an additional challenge for migrating Monarchs.
- A new spider species with a white cephalothorax was found in Australia. The link has an image of this unusual-looking spider.
- The western black rhinoceros is extinct in the wild according to a report by the IUCN. The same report notes that 25% of the world's mammals are facing extinction. Meanwhile, the Sumatran tiger continues to survive in what remains of its range.
Thursday, November 10, 2011
Review: Arctic Autumn by Pete Dunne
Pete Dunne's current writing project is a four-part series of books based on seasons in North America. The first was Prairie Spring, a book I have not read. The second, Bayshore Summer, a book I reviewed last fall,
was set in Cumberland County, New Jersey, where Dunne currently lives.
In the third volume, published this fall, Dunne turns his attention
northward in Arctic Autumn: A Journey to Season's Edge.
The "autumn" of the book's title is not autumn as readers in a temperate climate might conceive it. At northerly latitudes, the warm season is short and summer is fleeting. By the end of June, when summer in the temperate zone is just getting started, Arctic-breeding shorebirds are already starting to migrate south. Thus Dunne begins his narrative at the summer solstice in June and continues through to November, when polar bears near Churchill, Manitoba, begin moving from their dens on land out onto sea ice, where they will spend the winter hunting. The Arctic is so vast that it is impossible to cover all of it in one book. Instead, the chapters are vignettes, each taking place at a different site in a different part of summer.
While the book is nonfiction, it is told as a first-person narrative, almost like a travel diary. Pete Dunne and his wife, Linda, travel to different parts of the Arctic to experience the season for themselves. Some locations are visited with tour groups, like Bylot Island in Nunavut. Others are explored with smaller groups, like a caribou hunting trip Dunne took with a guide and one other person. The material in each chapter is based on their interactions with the natural world of the Arctic and with the people there. Chapters include dialogue with residents of the Arctic or people who lead tours there. Dunne interweaves his own experience of the places he visits with their natural history.
The impact of humans on the Arctic is never far from Dunne's narrative. Ecotourism has an impact, of course, since animals alter their behavior when they know they are being watched, plus there is the pollution created by flying hundreds or thousands of miles to visit the Arctic. (Its effects are not all bad, though, as ecotourism contributes to local economies and may provide an economic incentive for conservation.) Native residents also have an impact, though theirs is small.
Dunne is more concerned with the large-scale changes wrought by modern technology and energy use. Climate change is gradually reducing the area covered by sea ice and making survival more difficult for polar bears and other animals that depend on sea ice for part or all of their life cycle. It will surely affect other wildlife as well by changing when food becomes available or reducing permafrost. A second major impact is oil exploration. In the U.S., whether to open the Arctic National Wildlife Refuge to oil drilling has been a contentious political issue for the past decade. In places where drilling is allowed, like in the areas of the National Petroleum Reserve adjacent to Teshekpuk Lake Special Area, habitat is cleared to make way for infrastructure, and the site is often fouled by toxic chemicals. Beyond those obvious effects, there is a more subtle one. The pipelines, buildings, radar towers, and vehicles become inviting perches or nest sites for predatory birds, and the waste produced by human habitation attracts opportunistic scavengers. These scavengers would just as soon eat eggs and nestlings as other foods. The presence of these and other predators associated with human infrastructure puts additional pressure on the waterbirds and songbirds that breed in the Arctic. A third impact that Dunne discusses is hunting, both the small-scale sustainable hunting that Dunne and others practice and the large-scale market hunting that decimated the polar bear population in the 20th century prior to the signing of the Oslo Agreement in 1973.
Arctic Autumn showcases Pete Dunne's writing at its best. The narrative is engaging, occasionally humorous, and informative. At several points, I found myself wanting to visit the places Dunne describes, especially during the chapter about a canoe trip he and his wife took with two other naturalists down the John River in Arctic National Wildlife Refuge. The book is illustrated with Linda Dunne's photography – black and white photographs for the chapter headings and several plates of color photographs in the middle of the book. Readers interested in the Arctic and fans of Pete Dunne's writing should enjoy this book.
This review is based on a review copy provided by the publisher.
The "autumn" of the book's title is not autumn as readers in a temperate climate might conceive it. At northerly latitudes, the warm season is short and summer is fleeting. By the end of June, when summer in the temperate zone is just getting started, Arctic-breeding shorebirds are already starting to migrate south. Thus Dunne begins his narrative at the summer solstice in June and continues through to November, when polar bears near Churchill, Manitoba, begin moving from their dens on land out onto sea ice, where they will spend the winter hunting. The Arctic is so vast that it is impossible to cover all of it in one book. Instead, the chapters are vignettes, each taking place at a different site in a different part of summer.
While the book is nonfiction, it is told as a first-person narrative, almost like a travel diary. Pete Dunne and his wife, Linda, travel to different parts of the Arctic to experience the season for themselves. Some locations are visited with tour groups, like Bylot Island in Nunavut. Others are explored with smaller groups, like a caribou hunting trip Dunne took with a guide and one other person. The material in each chapter is based on their interactions with the natural world of the Arctic and with the people there. Chapters include dialogue with residents of the Arctic or people who lead tours there. Dunne interweaves his own experience of the places he visits with their natural history.
The impact of humans on the Arctic is never far from Dunne's narrative. Ecotourism has an impact, of course, since animals alter their behavior when they know they are being watched, plus there is the pollution created by flying hundreds or thousands of miles to visit the Arctic. (Its effects are not all bad, though, as ecotourism contributes to local economies and may provide an economic incentive for conservation.) Native residents also have an impact, though theirs is small.
Dunne is more concerned with the large-scale changes wrought by modern technology and energy use. Climate change is gradually reducing the area covered by sea ice and making survival more difficult for polar bears and other animals that depend on sea ice for part or all of their life cycle. It will surely affect other wildlife as well by changing when food becomes available or reducing permafrost. A second major impact is oil exploration. In the U.S., whether to open the Arctic National Wildlife Refuge to oil drilling has been a contentious political issue for the past decade. In places where drilling is allowed, like in the areas of the National Petroleum Reserve adjacent to Teshekpuk Lake Special Area, habitat is cleared to make way for infrastructure, and the site is often fouled by toxic chemicals. Beyond those obvious effects, there is a more subtle one. The pipelines, buildings, radar towers, and vehicles become inviting perches or nest sites for predatory birds, and the waste produced by human habitation attracts opportunistic scavengers. These scavengers would just as soon eat eggs and nestlings as other foods. The presence of these and other predators associated with human infrastructure puts additional pressure on the waterbirds and songbirds that breed in the Arctic. A third impact that Dunne discusses is hunting, both the small-scale sustainable hunting that Dunne and others practice and the large-scale market hunting that decimated the polar bear population in the 20th century prior to the signing of the Oslo Agreement in 1973.
Arctic Autumn showcases Pete Dunne's writing at its best. The narrative is engaging, occasionally humorous, and informative. At several points, I found myself wanting to visit the places Dunne describes, especially during the chapter about a canoe trip he and his wife took with two other naturalists down the John River in Arctic National Wildlife Refuge. The book is illustrated with Linda Dunne's photography – black and white photographs for the chapter headings and several plates of color photographs in the middle of the book. Readers interested in the Arctic and fans of Pete Dunne's writing should enjoy this book.
This review is based on a review copy provided by the publisher.
Wednesday, November 09, 2011
Birds at the Marina
Yesterday morning I walked through the site of the former Red's Marina in Highland Park. All of the marina buildings are now gone, and so are the boats. The site is now overgrown and in the midst of natural succession. Unfortunately a lot of the plants taking root there are invasive. Mugwort is especially conspicuous in the open areas at the site. There are a lot of native plants, though, enough to make the site attractive to birds passing through.
When I walked through the site yesterday, a lot sparrows were working an area that had been full of blooming goldenrod and boneset a month or so ago. There were Song Sparrows and White-throated Sparrows, of course, but also a handful of Swamp Sparrows. A Winter Wren chattered from the shrubs on one side of the site. When I looked in the other direction, a big flock of Golden-crowned Kinglets was working its way through the lower branches of the trees along the river. I reported 8 to eBird, but there could easily have been a lot more than that. Two Belted Kingfishers flying in tandem popped up over the shrub line, flew low over my head, and continued flying down the river. I assume these were a pair, but I did not get a good look at their chest markings.
The recently-released movie, The Big Year, highlights the competitive side of birding, in a particularly extreme form. A North American big year takes skill, but also the time and money to chase birds around the country. My typical experience of birding is a lot more like the paragraph above: appreciation of common birds, with an occasional rarity mixed in. I think that is probably true for a lot of other birders as well.
When I walked through the site yesterday, a lot sparrows were working an area that had been full of blooming goldenrod and boneset a month or so ago. There were Song Sparrows and White-throated Sparrows, of course, but also a handful of Swamp Sparrows. A Winter Wren chattered from the shrubs on one side of the site. When I looked in the other direction, a big flock of Golden-crowned Kinglets was working its way through the lower branches of the trees along the river. I reported 8 to eBird, but there could easily have been a lot more than that. Two Belted Kingfishers flying in tandem popped up over the shrub line, flew low over my head, and continued flying down the river. I assume these were a pair, but I did not get a good look at their chest markings.
The recently-released movie, The Big Year, highlights the competitive side of birding, in a particularly extreme form. A North American big year takes skill, but also the time and money to chase birds around the country. My typical experience of birding is a lot more like the paragraph above: appreciation of common birds, with an occasional rarity mixed in. I think that is probably true for a lot of other birders as well.
Tuesday, November 08, 2011
National Moth Week 2012
For over a decade, British moth enthusiasts have participated in National Moth Night, an annual event. In recent years, the event has become increasingly popular. Most observers record moths in their backyards, but some prominent institutions have set up moth traps as well. Next year, the United States will have a new mothing event, National Moth Week, which will be July 23-29, 2012. Here is Dave Moskowitz of the Friends of the East Brunswick Environmental Commission on the purpose of the event:
Why moths? With more than 10,000 species in North America alone, moths offer endless options for study, education, photography and fun. Moths can be found everywhere from inner cities, to suburban backyards and the most wild and remote places. The diversity of moths is simply astounding. Their colors and patterns are often dazzling or so cryptic that they define camoflauge. Shapes and sizes span the gamut with some as small as a pinhead and others as large as a hand.I have been to several moth nights in East Brunswick where I met Dave and other local moth enthusiasts. The events are fun to attend. On a good night in favorable habitat, there are plenty of moths to look at and opportunities to talk to people with similar interests. It is easy to find moths in your own backyard by leaving a porch light on or setting up a moth trap. Organizations also run moth nights easily as long as they have a good spot to set up a sheet and a UV light. For more information on participating, see the National Moth Week website.
Most moths are nocturnal creatures of the night, and need to be sought to see – others fly like butterflies during the day. Finding moths is easy and can be as simple as leaving a porch light on and checking it after dark. Serious moth aficionados use special lights and baits to attract them. Moths are also featured widely in literature and art providing a different angle for enjoyment and study.
Moth Nights are often held by nature groups and allow an easy opportunity for an introduction or for more serious pursuits. National Moth Week brings together everyone interested in moths to celebrate these amazing insects. It is hoped that groups and individuals from all across the country will spend some time during National Moth Week looking for moths and sharing what they’ve found.
During National Moth Week, attend a Moth Night event, start one, get some friends and neighbors together and check the porch lights from time to time, set up a light and see what is in your own backyard, read literature about moths. But no matter what, participate; the richness of moths is sure to fascinate. National Moth Week: Exploring Nighttime Nature.
Monday, November 07, 2011
Fall Colors at Lord Stirling Park
Even though a lot of trees have passed their peak foliage, some trees such as oaks still bear plenty of colorful leaves. A lot of colorful trees were on display at Lord Stirling Park on Saturday. Here are a few of the trees I saw. The one above is a sycamore along a boardwalk near the nature center. I forgot to check if this was a true sycamore or a London Plane. In direct sunlight, its leaves looked golden yellow.
This oak tree's looked more like orange brown.
Up close, this Red Oak's leaves looked bright red, especially when they were lit from behind in the morning sunlight.
This oak tree's looked more like orange brown.
Up close, this Red Oak's leaves looked bright red, especially when they were lit from behind in the morning sunlight.
Sunday, November 06, 2011
Sparrows at Lord Stirling Park
Yesterday, I visited Lord Stirling Park in Somerset County in the hopes of finding some sparrows. The park has a mix of woodland and meadow habitats in addition to the swamp that the area is known for. I have had some luck with sparrows there in past autumns, such as the Lincoln's Sparrow I found in 2007.
The morning started out slow, with some flocks of White-throated Sparrows and Dark-eyed Juncos but not much else. As I continued around the trails, I found a few Eastern Bluebirds. One of the bluebirds flew up to a nesting box, clung to the front of the box, and stuck its head through the entrance hole as if it were feeding a nestling or checking out the cavity. Soon it was joined by a second bluebird, and both birds perched on top of the box. I am not sure exactly what it was doing. It seems too late for nestlings, so perhaps it found a source of invertebrates, maybe a spider web or a mass of insects seeking a sheltered place to spend the winter.
When I got to the farthest meadow, near the west observation platform, I finally found some bigger sparrow flocks, though most of the birds were either White-throated Sparrows or Dark-eyed Juncos. A few flocks included Swamp Sparrows and Song Sparrows. As I rounded the south end of the main pond on my way back to the parking lot, I enjoyed a nice view of a Fox Sparrow, a highlight on almost any birding trip.
The morning started out slow, with some flocks of White-throated Sparrows and Dark-eyed Juncos but not much else. As I continued around the trails, I found a few Eastern Bluebirds. One of the bluebirds flew up to a nesting box, clung to the front of the box, and stuck its head through the entrance hole as if it were feeding a nestling or checking out the cavity. Soon it was joined by a second bluebird, and both birds perched on top of the box. I am not sure exactly what it was doing. It seems too late for nestlings, so perhaps it found a source of invertebrates, maybe a spider web or a mass of insects seeking a sheltered place to spend the winter.
When I got to the farthest meadow, near the west observation platform, I finally found some bigger sparrow flocks, though most of the birds were either White-throated Sparrows or Dark-eyed Juncos. A few flocks included Swamp Sparrows and Song Sparrows. As I rounded the south end of the main pond on my way back to the parking lot, I enjoyed a nice view of a Fox Sparrow, a highlight on almost any birding trip.
Saturday, November 05, 2011
Honey Locust
This is an old and magnificent honey locust tree that I see every day. Honey locusts have compound leaves with tiny leaflets that turn golden yellow in the fall. Up close, the leaflets are not that impressive, but from a distance the tree looks like a mass of gold. There was another old and magnificent tree, an elm, that stood next to this honey locust, but it was removed this summer due to disease. That made me wonder how much longer I would be able to enjoy this marvelous tree.
Friday, November 04, 2011
Loose Feathers #315
Sanderling / Photo by Keenan Adams (USFWS) |
- A study concluded that birds passing though central California have been growing larger in response to climate change. The study used banding data collected over the past forty years at Point Reyes Bird Observatory. Meanwhile, birds elsewhere have been shrinking rather than growing according to research conducted in eastern North America.
- Experiments showed that Eurasian Jays plan for the future by caching food that they may want to eat but will be in short supply later.
- Gunnison Sage Grouse prefer isolated nest sites that are over a mile from human development.
- NPR has a slideshow of seabirds killed by eating plastic. These are albatross chicks on Midway that were fed bits of plastic by their parents until their guts became too full of plastic to process real food.
- Whooping Cranes are arriving at their winter habitat in Aransas NWR. There is some concern that the cranes may be affected by an ongoing outbreak of red tide, which has killed 4.2 million fish since September.
- Researchers found the remains of a bird colony from the Cretaceous in Transylvania. The colony was probably swamped by a sudden flood that left eggshells and dead birds in its wake. At the time, Transylvania was an island inhabited by a variety of unusual dinosaurs. The birds in the colony were enantiornithines, with toothed beaks and claws on their wings.
- Seabird colonies in Scotland had yet another poor breeding season. The colonies have fallen over 53% since 2000.
- A survey in Australia was dedicated to finding the remaining population of the Orange-bellied Parrot, one of the world's rarest parrots. There are less than 50 left in the wild, mostly near Melbourne.
- Meanwhile, the overall outlook for Australian birds has worsened according to a report from last year. For a variety of reasons, from invasive species to fire practices, 13% of Australian bird species are considered threatened or worse.
- An exhibit in London features art work commemorating birds that have been lost to extinction.
- A rare white kiwi in New Zealand survived surgery to remove a blockage from its gizzard.
- Not Exactly Rocket Science: Stunning wren duets are conceived as a whole but sung in two parts
- 10,000 Birds: Vesper Sparrow Pooecetes gramineus
- Maniraptora: Evolution of Hawai'ian honeycreepers
- Mike's Birding and Digiscoping Blog: The Impulse to Chase
- Net Results: Myth-busting: Birds, buckthorn, and diarrhea
- BHL: Book of the Week: Voyages to South America
- The Daily Wing: Ten Tips for Winter Birding
- Birding Is Fun!: Big Brown Bird with a sharp tongue and a limp
- PetaPixel: Breathtaking Murmuration of Starlings Caught on Camera
- The Nemesis Bird: TRULY rare birds
- A new study finds that the summer dead zones in the Chesapeake Bay have declined over the past few decades thanks to efforts to reduce pollutants upstream.
- DNA barcoding of crustaceans found on dead corals suggests that coral reefs may hold more biodiversity than thought.
- A trade association of Gulf fishermen is starting a program to certify fish to reduce concerns about seafood mislabeling.
- Climate change, invasive insects, and other causes are pushing trees to shift their ranges across the American West. Among the findings is that lodgepole pine and Engelmann spruce will decline while Douglas fir and western hemlock will expand. Wetter areas in the Pacific Northwest will see less change than drier areas elsewhere.
- South America was home to a small mammal with unusually large teeth in the Late Cretaceous.
- Two herpetologists are trying to save the endangered frogs in Ghana.
- A project is underway to capture trash floating down the Los Angeles River before it reaches the sea. Trash screens will catch and collect debris at storm drains before it causes problems downstream.
- Odorous house ants, common on the mainland United States, are now invading Hawaii.
- Three new unusual-looking tube-nosed bats were discovered in the forests of Cambodia and Vietnam. The link has photos of the new species.
Thursday, November 03, 2011
Green Standards to Incorporate Bird Safety
For a long time, green building standards, as codified by the LEED program, focused on a building's energy use, often to the exclusion of other environmental considerations. One significant problem is that LEED-certified buildings often have large expanses of glass to let in light and heat and reduce energy use. Those same energy-efficient windows attract birds, which crash into the windows when they mistake reflections for trees and sky. Thanks to the work of the American Bird Conservancy and the Bird-Safe Glass Foundation, LEED certification will soon include credits for reducing bird fatalities.
To earn the credit, buildings must comply with one facade requirement, one interior light requirement and one exterior light requirement and develop a monitoring program.This looks like a step in the right direction. A green building ought to be safe for wildlife, to the extent that this is possible.
The facade requirement focuses on the creation of “visual noise” to help birds distinguish inviting sky from unwelcoming wall by the making glass less reflective and more textured and/or opaque.
The lighting requirements can be met through actions as simple as turning off all the interior lights in a building at night or making sure that exterior lights are not angled up into the sky.
Wednesday, November 02, 2011
Invasive Mussels and Birds
Quagga Mussel / USGS Photo |
One way is through food availability:
Gary Montz, an aquatic invertebrate biologist with the Minnesota Department of Natural Resources, said, "If we see a disruption in the base of the food chain by extremely high densities of zebra mussels, this could impact food for larval fish. That in turn could impact other aquatic life that depend on such fish."
That includes fish-eating birds -- loons, mergansers, grebes, cormorants, scoters and gulls.
Zebra Mussel / USGS Photo |
"Zebra mussels have a connection with avian botulism," said Carrol Henderson, superintendent of non-game wildlife for the DNR. Botulism is a byproduct of mussel waste. The waste is eaten by fish, which then can infect fish-eating birds.
Thousands of birds in the eastern Great Lakes have died of botulism poisoning since 1999. Species again include loons, mergansers, grebes, cormorants, scoters and gulls.
Some species of diving ducks eat the mussels. Zebra mussels have been a dominant food consumed in the eastern Great Lakes by greater and lesser scaup and bufflehead ducks. Concentration of trace elements in the mussels kills the birds.
The scaup population fell from an estimated 7.5 million breeding birds in the 1970s to fewer than 4 million in 2005, according to author James H. Thorp. The figures come from his book "Ecology and Classification of North American Freshwater Invertebrates."
Tuesday, November 01, 2011
Leaves in the Snow
Some snow remains from Saturday's snowstorm. The piles of snow here and there create the unusual sight of bright fall foliage on or under snow. Here are a few leaves from a flowering dogwood in the snow.