Sunday, June 30, 2013

Six-spotted Tiger Beetle

This beetle is a relatively unspotted Six-spotted Tiger Beetle. The species is found in Minnesota and much of eastern North America. These beetles feed on other insects like caterpillars, ants, and spiders and thus are generally welcomed by gardeners.

After hatching, tiger beetle larvae make burrows, where they wait for their prey. Often they attack from the burrows “much like jack-in-the-boxes” (Wikipedia). The larvae live for about a year before pupating (and live for about 4 more years as adults). At night, adults return to their larval burrows. They also over-winter in the burrows (Mark Moran).

Six-spotted Tiger Beetles often have six spots on their emerald fore-wings. This field mark, as you can see, is not invariably present. I can make out two or three tiny spots on this individual. Others may have as many as ten.

Friday, June 28, 2013

Snapping Turtle

On our way down to the Bass Ponds in the Minnesota Valley National Wildlife Refuge, Erika and I stumbled over a Snapping Turtle. The reptile was probably touring, in search of a good egg-laying site. Note the leaches hitch-hiking on the turtle’s rear leg. No doubt the turtle provides both nourishment and a means of distribution for the leeches.

Despite being common (if not abundant) in Minnesota, Snapping Turtles are listed as a species of Special Concern in the state. Humans are about their only predator. Snappers are harvested for their meat, and the effects of commercial harvesting are unknown. Minnesota allows unlimited hunting of snappers with shells over a foot. Most of this hunting is in June, which is unfortunately just when turtles are laying eggs, thus affecting their reproductive potential. Snapping Turtles also harbour high levels of PCBs, which also may affect their reproductive capacity (and possibly also of that of humans who eat them) (MN DNR).

Snapping Turtles are sometimes thought to prey upon fish and waterfowl. They are, indeed, fairly omnivorous. These turtles, however, have been shown to eat “insignificat” numbers of game fish and mammals and large fish are a far more serious threat to nesting waterfowl (MN DNR).

Thursday, June 27, 2013

Painted Turtle

I have previously blogged on Painted Turtles in 2011. Erika and I encountered this gorgeous individual at the Bass Ponds in the Minnesota Valley National Wildlife Refuge in Bloomington last week. This species is Minnesota’s most common turtle. They are omnivorous, they eat almost anything they can catch. They should not, however, be kept as pets. They require specific temperatures to thrive and tend not to do well with artificial diets. Furthermore, Painted Turtles carry salmonella, a very unpleasant digestive disease that does affect humans. Being hit by cars as the turtles try to cross roads is a major source of turtle mortality.

We flipped this turtle to see its colorful underparts. As we did so, the turtle responded by releasing copious urine. We set the turtle upright as we left it to its travels.

Wednesday, June 26, 2013

Blanding’s Turtle

The last thing Erika and I expected to see during a recent tour of Minneapolis water features was a woman with a Blanding’s Turtle under her arm. Any turtle would have been a surprise, but especially one classified as Threatened in Minnesota. This species is found from Minnesota and Nebraska east to New England. Nowhere is it common. Threats include habitat fragmentation and destruction and predators. Many are killed as they attempt to cross highways.  Females often nest in agricultural fields and thus are threatened by "chemicals, disking, machinery usage, increased nest predation, and shade produced by growing crops" (MN DNR).
Blanding's Turtles take 14 to 20 years to reach sexual maturity and may live up to 80 years. Typical of a long-lived species, they lay few eggs—only an average of eight per clutch (Wikipedia). This low reproductive rate makes recovery from ecological threats all the more difficult—mortality rates reaching 93% are reported for eggs and young (MN DNR).

They hibernate under mud and vegetation in ponds, from whence they may travel up to a mile (thus exposing themselves to the risk of automobiles on roads). They are agile swimmers and are omnivorous, consuming invertebrates, small vertebrates, and vegetation. Field marks include the spots on the upper shell and the bright yellow throat and chin.

The Minnesota Department of Natural Resources warns that possessing Blanding’s Turtles is illegal. The woman we met on our tour was quick to assure us that she found this turtle in the road near Farmington, and planned to release it in a wild area “up north.” My impression that the woman had contacted the DNR about her transplant plan—we just hope that this Blanding’s Turtle does not have strong homing instincts, crawling home across the highways of Minneapolis/St. Paul.

Monday, June 24, 2013

Review: The Warbler Guide


The Warbler Guide is a stupendous new book by Tom Stephenson and Scott Whittle, published by Princeton University Press. Each of the 56 species accounts contain at least a dozen photographs, emphasizing various plumage variations—in all, over 1000 stunning color photos grace the book. One of the unique features of this book is that many of these photos are taken from below, which is how you really see warblers in the field. Each account also contains photos showing distinctive features and comparison species. Range maps accompany each account.

The long introduction discusses what to look for when seeing a warbler. This section includes warbler photos showing field marks and suites of spring and fall warblers, all on the same pages (from the side, at a 45 degree angle, from below, as well as close-ups of warbler heads). The authors also launch into a long discussion of sonograms that illustrate warbler songs in each species account.

The book ends with a spreadsheet comparing warbler behavior and habitat (both also covered in the species accounts) and a short quiz emphasizing warbler identification. Also presented are a short series of birds likely to be confused with warblers (although I can’t imagine an Eastern Towhee could be confused with a warbler). Finally, a few photos of warbler hybrids are included. The book is sparsely referenced, but does include a few resources, in print, in audio and digital format, and on the Internet.

This relatively inexpensive book will aid birders of all abilities in identifying the warblers of America. The list price is $29.95. Prepublication orders (before the first week in July) from Amazon are $19.36!

Update: see my review of the audio files Cornell Ornithology lab has just published to accompany The Warbler Guide.

Sunday, June 23, 2013

Field Sparrow

When we visited Faribault in May, Erika and I banded a Field Sparrow, a species I have ringed several times at our Dundas banding station. These sparrows are common in eastern North America. They breed in brushy pastures and scrublands, but, to their detriment, seldom in similar urban habitat. Across their range, Field Sparrows appear to be declining in numbers, either because their habitat is becoming forest or becoming urbanized (Carey et al. 2008).

Friday, June 21, 2013

Jade Clubtail

Until Wednesday, Jade Clubtails were known to occur from southeastern South Dakota (one record), Iowa, Indiana and Illinois south to eastern Texas and Louisiana (Odonata Central). On Wednesday, Erika and I made the first-ever observation of this dragonfly in Minnesota—at the Bass Ponds in Bloomington at the Minnesota Valley National Wildlife Refuge.

I immediately knew this was a dragonfly I had never seen—the chestnut tail told me that. Species identification was also aided by the critter’s green (not blue) eyes, black lines along the sides of the thorax, and the yellow appendages at the tip of the abdomen. The behavior and habitat also indicated a Jade Clubtail. This odonate perched on the ground near the bass ponds and the nearby forest. These clubtails prefer large, mud-bottomed lakes, sloughs, canals, and slow-flowing rivers (Paulson)—a perfect description of the Bass Ponds.

I shared these photos with Scott King, who concurred with my identification. Odonata Central also vetted the record.

Thursday, June 20, 2013

Red-winged Blackbird

Because Red-winged Blackbirds are among the most abundant North American birds—they range from Alaska and northern Canada south through Central America—I have posted various photos of this handsome species. (See, for example, this post from 2011, or check out the species index tab at the top of this blog.) Familiarity, plus their huge flocks with their potential for damaging crops, may dampen our appreciation for these striking birds. (People are now one of the major causes of mortality for Red-winged Blackbirds (Yasukawa and Searcy 1995).)

Why is this blackbird so abundant? Their habitat includes both freshwater and saltwater marshes, the edges of ponds and streams, wet roadsides, dry meadows, and old fields (Allaboutbirds). I suspect the building of the Interstate Highway System has contributed to greatly expand the Red-wing’s range across North America—the highway right-of-ways are perfect habitat for this species.

Despite their abundance, I do not band many Red-winged Blackbirds. They seldom visit my urban bird feeders and are wary at our Dundas station. The male and female blackbirds on this post were banded and photographed during a public banding demonstration that Erika and I presented at the River Bend Nature Center near Faribault, Minnesota, this May. People attending had no trouble identifying the male, but had more difficulty recognizing the female below.

Tuesday, June 18, 2013

Common Grackle

Previously I blogged about the beauty of Common Grackles. I suspect you would agree with me about the beauty of this species if I told you that this photo is of a rare bird-of-paradise—but it is not, just a grackle.

One of my mentors, Alan Phillips, was fond of quoting “if ever I am accused of destroying the crops, I certainly would want an ornithologist to defend me.” Nevertheless, Common Grackles are “now among the most significant agricultural pest species in North America, causing millions of dollars in damage to sprouting corn.”  Not only that, they eat bird eggs and nestlings, and even other adult birds. If that reputation was not enough, grackles may carry the fungus that causes histoplasmosis, a respiratory disease that can be fatal to people. Grackle roosts are often sprayed with detergents which wash off the protective oils on bird feathers, leaving the grackles damp and vulnerable to exposure. Perhaps due to these and other control measures, at least in the East, grackle populations are in decline (perhaps as much as by 30% between 1966 and 1993). Western populations, however, are increasing and spreading westward. Most of this information and the second quote are from Peer and Bollinger 1997).

I took this grackle photo of a bird being banded in Northfield, Minnesota. At the time I did not notice the small arthropod on its lower mandible—no idea what the creature might be.

Monday, June 17, 2013

Stink Bug

This arthropod is a green stink bug I found in Erika’s garden—I am not sure of the exact species. I did learn a new word—polyphagus. This word means that it eats a lot of stuff, but is not quite omnivorous, which would mean it eats anything. This bug can be a pest on many vegetables and fruits. The silver lining with stink bugs is that birds toads, spiders and other insects prey upon them. Green stink bugs are found across most of the United States and Canada. I did not pick up this stink bug, thus I can not report to you how it smells.

Sunday, June 16, 2013

Midland Clubtail

Midland Clubtails have visited Erika’s garden before, but they looked slightly different from the one I photographed on one of her rhubarb leaves. The spot on the terminal end of the abdomen is variable in Midland Clubtails in Minnesota (Scott King, pers. com.). Field marks include the yellow spots on the edges of the last two abdominal segments combined with those two segments being unspotted on their upper surfaces. These odonates are voracious predators, even able to prey upon other dragonflies. Since females oviposit in rapids, perhaps this species is attracted to our rushing water feature (if not the half-dozen Common Whitetails and Twelve-spotted Skimmers floating over Erika’s garden).

Saturday, June 15, 2013

Western Tanager

Hudon (1999) describes Western Tanagers as “a quintessential element of western forests.”  This species breeds in the Rocky Mountains from southern Alaska to the southernmost United States. They are inconspicuous on their breeding territories, but may be common during migration in city parks and other open areas. Especially in the fall and early winter, strays occasionally visit Minnesota and other eastern states.

Curiously the red color of Western Tanagers differs from other tanagers in the United States and Canada. The others deposit red 4-oxo-carotenoids in their plumage. They produce this pigment from dietary yellow pigments. Western Tanagers, however, deposit rhodoxanthin, a rare red pigment, that must be obtained from food sources, presumably insects upon which the species feeds (Hudon 1999).

I took this photo of a pair of Western Tanagers many years ago. To the best of my recollection, the location was near Taos, New Mexico.

Friday, June 14, 2013

Taiga Bluet

My second Odonate of the year is a new one for me—a Taiga Bluet. On Monday, 8 June 2013, Erika and I found Scott King in the Carleton College Lower Arboretum. Nothing like having a local dragonfly expert in place and ready to point out damselflies! Scott found this species a few minutes before we arrived and offered to show it to us. We wondered if it had stayed put, but Scott assured us that one of this species's traits is the habit of remaining relatively still. Scott informed us that he has seen very few Taiga Bluets in Rice County. This individual was on aphid-invested undergrowth and Poison Ivy along the Cannon River.

Taiga Bluet field marks include the three relatively dark abdominal segments in front of the terminal blue tip, a U-shaped black mark in the blue on the anterior end of the abdomen, and blue sides the become greenish on the sides bottom of the thorax. This greenish color is hard to see on my photograph, but is visible below the eye and the base of the legs.

Taiga Bluets range across Canada south to Iowa, and Wisconsin in our area, Pennsylvania in the east, and through the Rocky Mountains to California, Utah, and Colorado in the west. The species is found north to the Arctic Ocean. This species’s heartiness is reflected in its scientific name, Coenagrion resolutum. The larvae are able to over-winter even in its hostile environment. The larvae are often embedded in ice, yet they do not freeze (Dubois). Their tissues must contain a natural antifreeze (a phenomenon known in other cold-water animals).

Thursday, June 13, 2013

Lewis and Clark 3: Clark’s Nutcracker

When William Clark first saw a Clark’s Nutcracker (so named by Alexander Wilson when scientifically describing the species), Clark thought it was a woodpecker. Now it is classified with the crows and jays. This nutcracker is found in the Rocky Mountains of the United States and Canada. This photo, taken several years ago, is from Mount Rainier National Park.

The species is a highly specialized pine seed forager. Several pine species depend on nutcrackers to distribute their seeds, thus forsaking wind dispersal. Nutcrackers have a pouch under their tongues that they use to transport seeds to cache sites. The birds have excellent spatial memory, which allows them, even after a year, to relocate their seed caches, which can number in the thousands. If, for whatever reason, a nutcracker fails to relocate its cache, the seeds may germinate. Consequently these pines often grow in small clusters (Tomback 1998).

Wednesday, June 12, 2013

Lewis and Clark 2: Lewis’s Woodpecker

On 20 July 1805, Meriwether Lewis wrote, “I saw a black woodpecker (or crow) today… it is a distinct species of woodpecker; it has a long tail and flys a good deal like the jay bird” (Vierling 2013). Later the ornithologist Alexander Wilson scientifically described and named this bird after Lewis. A skin of the Lewis’s Woodpecker at the Harvard Museum of Comparative Zoology is perhaps the only surviving intact specimen taken during the Lewis and Clark expedition (Johnsgard 2003).

Lewis’s Woodpeckers look strange. They have a flight pattern that looks more like a crow than a woodpecker. The species is found across western North America. They are not good excavators, so require snags in dead or partly dead trees and need decayed wood in which to drill nest holes. Often good places to search for Lewis’s Woodpeckers are recently burned forest tracts. On the other hand, I took this photo of a woodpecker on a suburban rooftop several years ago on the outskirts of Missoula, Montana.

(Note from previous Lewis and Clark post: I have since discovered that the Clark’s Grebe is not named for Meriwether Lewis’s co-leader William Clark, but John Clark, an early American naturalist and surveyor.)

Tuesday, June 11, 2013

Bell’s Vireo

Word of a Bell’s Vireo in Rice County, Minnesota, near Big Woods State Park, filtered to me via friends and the MOU listserv. After a busy day, Erika and I searched for the bird late Monday afternoon. We immediately heard and saw it at the first stop sing west of the state park, as Dave Bartkey posted on the listserv. The species is found in the central and southwestern United States and is considered to be rare and local in Minnesota.

I have previously posted about Bell’s Vireos. Oddly, the habitat were we found this bird seems to be atypical for this riparian species. With no river very close, two birds sang vociferously from overgrown, shrubby, hilly pastureland. Thinking back on other Bell’s Vireos that I have seen in South Dakota, all were within a few meters of rivers, lakes, or drainage areas. I can find no literature reference of females singing and defending territory, thus I suspect we observed two males.

Sunday, June 9, 2013

Lewis and Clark 1: Clark’s Grebe

One of the last birds that John Holden and I saw on our May South Dakota trip was a Clark’s Grebe. The rain was a downpour, but racing at such an angle that I was able to get this photograph from our car’s open window. I have previously blogged on how to identify this grebe, but seeing it started my wondering what birds have common names commemorating Lewis or Clark.

After Lewis and Clark returned from their explorations to secure the Pacific Northwest for the United States, Thomas Jefferson sent three of their bird specimens to Alexander Wilson for scientific description. The literature is a bit difficult to decipher as to what these three may be. Presumably they are Clark’s Nutcracker, Lewis’s Woodpecker, and, perhaps, the Greater Sage-Grouse. The former two species are the only birds I can find bearing the names of Lewis or Clark, plus the Clark’s Grebe which was considered for many years to be but a color morph of the Western Grebe. Further investigation reveals that the Clark’s Grebe is not named for William Clark of Lewis and Clark fame.  Instead the name honors John Henry Clark, a 19th-century American surveyor and naturalist.

Wikipedia lists seven birds described for the first time by European Americans during the Lewis and Clark Expedition. In addition to the three already mentioned, are Common Poorwill, Interior Least Tern, McCown’s Longspur, and Trumpeter Swan. But here “described” is not used in the scientific context, but rather that Lewis and Clark mention them in sufficient detail to know what they saw. Johnsgard (2003) cites literature listing a total of 25 birds that are also mentioned by Lewis and Clark.

Saturday, June 8, 2013

Black-crowned Night-Heron

On our return to Minnesota from South Dakota, rain drove mercilessly across the highway. How do birds keep dry in the rain? Theoretically, birds keep dry by oiling their feathers from secretions from an oil gland on their rumps. Water slides off the oil, leaving the birds dry. I write “theoretically,” because this Black-crowned Night-Heron is looking drenched—its wing coverts are becoming matted and water is dripping off the tip of its bill.

Black-crowned Night-Herons are found around the world, except Antarctica and Australia. They are usually hard to see because they feed at dusk, night, and at dawn. They eat fish and other aquatic animals. Because of this diet, night-heron tissues accumulate contaminants such as DDT. Populations have rebounded with the advent of modern environmental protection, and currently numbers in North America appear to be on the increase (Hothem et al. 2010).

I have previously blogged about night-herons.  This photo was taken in central South Dakota along Highway 12.

Friday, June 7, 2013

Eurasian Collared-Dove

Returning to South Dakota after a seven-year absence, I was surprised by the abundance of Eurasian Collared-Doves. When I left the state, about the only reliable place to see them was in the Pierre area. Previously I posted a photo of a large flock of these doves from Pierre, and there I wrote about the doves’ spread across North America. Nevertheless, I was not expecting the species to be abundant in Mobridge and Timber Lake (the later town not even on the Missouri). The courting Eurasian Collared-Doves in this photo were in Timber Lake.

Factors responsible for this dove’s spread across the continent include its ability to make long-distance dispersal flights, multiple releases in the United States, backyard bird feeders, locations with stored and waste grain, and an increasing planting of trees (Romagosa 2012). Indeed, a good place to find this dove is near grain bins in small rural towns.

Thursday, June 6, 2013

Lark Sparrow

I have previously blogged about the Lark Sparrow, now a western bird found east only to Minnesota and Iowa. Formerly the species was found all the way to the Atlantic coast, spreading there after the eastern forests were cut with the advent of European settlement. Now that the fields are returning to forests or supplanted by urban development, Lark Sparrows are now rare birds in the East.

These photos were taken this May of singing Lark Sparrows near Timber Lake, South Dakota. Erika and I occasionally see them in Rice County, Minnesota, and most years we find them along the Cannon River Bike Trail in nearby Goodhue County. We found a singing bird there on Monday. According to Martin and Parrish (2000), no definitive studies of Lark Sparrow biology have been undertaken.

Wednesday, June 5, 2013

Burrowing Owl

I have blogged that prairie dogs are despised by many ranchers—a hatred that is bad news for Burrowing Owls, who often live in prairie dog burrows. The owls are now listed as Threatened or Endangered in Canada. In Mexico this owl is listed as requiring Special Protection. By not designating the Burrowing Owl as Threatened or Endangered, the Federal Governement in the United States bowed to pressure from ranching interests who fear the rise of prairie dogs if Burrowing Owls are protected. Nevertheless, several states protect Burrowing Owls (Minnesota, Colorado, Montana, Oklahoma, Oregon, Utah, Washington, and Wyoming). Burrowing Owls are killed by ranchers shooting at prairie dogs and ranchers often destroy whole prairie dog colonies. Intensive cultivation of grasslands and the ever-encroaching specter of urban development also destroy habitat. Pesticides used against prairie dogs are also toxic to the owls.

For all these reasons, the Burrowing Owl we saw must be one of the highlights of John Holden’s and my trip to western South Dakota. The absolute best birds, however, were two Scissor-tailed Flycatchers, a bird not often reported from the state. Unfortunately our flycatchers were about a half-mile distant. Serrendipitously I took a photo anyway, and if you are interested in one of the world’s worst photos of a Scissor-tailed Flycatcher, check it out on my eBird list.

Tuesday, June 4, 2013

Eastern Kingbird

I have always thought the Eastern Kingbird to be inappropriately named. After all, this bird is found from coast to coast across North America, being absent only from the Southwest. When John Holden and I visited South Dakota last month, Eastern outnumbered Western kingbirds even west of the Missouri River. I think a better name might be the translation of its Spanish name, Pitirre Americano, or American Kingbird. This species is, after all, almost red, white and blue. OK, so it is bluish gray, and the red is hidden in its crown. So how about another Spanish appellation, Tirano Viajero, or Traveling (or Migrant) Kingbird? Erika and I saw huge flocks of Eastern Kingbirds in the winter when we studied in the Ecuadorian Amazon.

Eastern Kingbirds tend to be monogamous and usually retain the same mates over subsequent years. However, extra-pair copulations have been observed and they will lay their eggs in other birds’ nests, even birds of different species. The males guard while the females build nests, either to warn her of predators or to keep her from mating with other males (Allaboutbirds.org). Only single broods are raised each season, presumably due to the high energy required for flycatching and subsequent long periods of parental care (Murphy 1996). In a previous blog, I posted photos of young Eastern Kingbirds.

Sunday, June 2, 2013

Swainson’s Hawk

Swainson’s Hawks migrate each year from the Great Plains of North America to the pampas of of Argentina, a distance of some 10,000 kilometers. West of the Missouri River in South Dakota, John Holden and I found them to be the most common raptor. The species is in some peril—studies have demonstrated that, in Argentina, thousands of Swainson’s Hawk are poisoned by pesticides (Bechard et al. 2010). I have previously posted on this hawk.

These hawks come in three color phases. Bechard et al. (2010) write that there are light-morph birds, like the hawk in the upper photo, dark-morph ones, and everything else inbetween. The authors appear to claim that a third, rufous-morph exists, like the one John and I found and photographed below. Sibley (2000), however, implies that the rufous birds are simply intermediate between the light and dark birds.

Why do many hawks come in dark and pale morphs? One hypothesis is that the pale birds (usually outnumbering the dark ones) are learned by the prey. Consequently the pale morph declines while the dark one increases—until the prey learns that dark raptors are also dangerous. Then the dark ones decline and the pale ones increase. I do no know if an hypothesis for three morphs exists. The situation with Swainson’s Hawks is complicated. In California, 89% of males were pale. In breeding pairs, males tended to be paler than females (Bechard et al. 2010).

Saturday, June 1, 2013

Lark Bunting

At the recent South Dakota Ornithologists’ Union meeting, John and I elected to more or less accompany a field trip heading west of the Missouri River. Our goal was to try to find western birds that we could not easily see at home in Minnesota. As I explained in my last post, at least in South Dakota, the river separates eastern and western avifaunas of the United States. This is not a strict rule, however, because birds have unique ranges and because distributions are not static. For example, 20 years ago Lark Buntings bred at least to the Aberdeen area; this year John and I did not see them until we were west of the river. (Lark Buntings are considered to be casual in Minnesota.)

Lark Buntings are among the six songbirds endemic to North America’s grasslands (Shane 2000). Unlike almost all other sparrows, the male is drab in the winter but molts into a striking breeding plumage. This Lark Bunting, photographed near Timber Lake, South Dakota, is probably in its  second year, since the bird has retained its warn, brownish tail feathers, left over from its first winter plumage. I wrote about this species last January.