Saturday, June 30, 2012

Blue Dasher

Last year I blogged on the Blue Dasher dragonfly. Last week Blue Dashers were abundant at Lebanon Hills Regional Park in Dakota County, Minnesota. Above is a male Blue Dasher from last year. The photograph below, from this year, threw me a bit, because I was unsure what to make of the red cap. Apparently the red is a trait of relatively young males.

Trying to learn to identify dragonflies over the past two years has been an interesting exercise. I have gained some insight into the learning process--repetition, repetition, repetition are the keys. A youthful brain might help too, but there is not much I can do about that.  Odonates (dragonflies and damselflies) are so variable! Sexes and age classes differ, regional variations, microscopic differences, and females appearing in separate colors or masquerading as males all complicate identification.

Friday, June 29, 2012

Chihuahuan Raven

My New Mexican brother is an accomplished herbalist and birder. When I complained that I lacked a photograph of a Chihuahuan Raven, my brother replied that, although difficult to distinguish from Common Ravens, he had it figured out. As you drive north of Silver City, look for Chihuahaun Ravens in dry areas at lower elevations near human habitation. Common Ravens are found higher in the mountains in forested areas. Bednarz and Raitt (2002) agree with my brother's assessment, although they warn that mixed flocks of both raven species and American Crows have been reported. These authors write that the "combination of large flocks in open plain and desert habitats [are] typical only of [the] Chihuahuan Raven."

Chihuahuan Ravens are found from parts of the American Southwest south to central Mexico. In a small, low-elevation town we found what appeared to be an all-black raven. "This all adds up to Chihuahuan Raven," said my brother. Imagine my surprise when I cropped and enlarged this photograph. Not only can you see white bases to the neck feathers (one of the key field marks to the species, marks that are usually hard to see), the lower breast and undertail feathers are also have white bases. I have not seen mention of these later attributes.

The biology of the Chihuahuan Raven is relatively unknown. This bird is social, found in flocks most of the year. They build groups of up to five nests in a single area, but the reasons for this behavior are unknown. Flocks of ravens defend their nests communally. After the nesting season, groups of up to 500 ravens roost together (Bednarz and Raitt 2002).

Thursday, June 28, 2012

Spotted Towhee

After leaving Texas last March, Erika and I spent two days in New Mexico. We attended to some automobile maintenance and visited my brother. This Spotted Towhee greeted us to the state. Last year I blogged about the differences between Spotted and Eastern towhees (including links to their calls).

Spotted Towhees are territorial, as perhaps you can guess from this photograph taken by Erika. They are also monogamous. Both Eastern and Spotted Towhees usually forage on the ground, scratching simultaneously with both feet to search food under leaf litter (Greenlaw 1996).

Wednesday, June 27, 2012

Edward's Hairstreak

The Edward's Hairstreak is a common butterfly of the eastern United States. Caterpillars use oaks as host plants.  Adults sip nectar from various flowers, including goldenrods, sumac, white sweet clover, and, as you can see in this photo, milkweeds. This butterfly's larvae is tended by ants. The ants consume nectar from the larvae and, in return, protect the larvae (and adults) from predators (Ohio DNR).We found this hairstreak in Carleton College's Upper Arboretum (a few minutes after finding the Delaware Skipper of a recent post).

Tuesday, June 26, 2012

Red Saddlebags

I photographed this female Red Saddlebags on Sunday in Carleton College's arboretum. This dragonfly gets its name from the red wing-bases, which you can see in a male saddlebags in the third photograph that I took last March in the Santa Ana National Wildlife Refuge in Texas. The species is found across much of North America, and south into northern South America. Red Saddlebags are less common in the north, but are known from southern Minnesota. This year saddlebags are appearing here in record numbers. Global warming? Natural cycles?

Monday, June 25, 2012

Delaware Skipper

Skippers are small, difficult-to-identify butterflies. The key to this Delaware Skipper is the black lines on the upper wings. Erika, Scott K., and I encountered this male in Carleton College's Upper Arboretum. The species is widespread across most of the United States east of the Rocky Mountains where it is usually fairly common. Adults feed on pink and white flowers (milkweeds, mints, fleabane, and thistles, among others) while various grasses serve as hosts for the caterpillars (Butterfliesandmoths.org).

Sunday, June 24, 2012

Ringed Kingfisher

You may recall that, last March, Erika and I swung down to Texas on our way to Olympia to greet a grandchild into this world. Texas afforded us great birding--we reported 141 species to eBird. This total was more than any other state we visited. Mitigating factors include more time devoted purely to birding and more time in the state. (Other totals include California, 104; Arizona 30; New Mexico 36; Oregon 33; and Washington 48.)

Leaving Eagle Pass, Texas, as we headed west, I turned to Erika (who was driving) and announced, "we REALLY need to make a U-turn!" On a telephone wire over Elm Creek perched a kingfisher on steroids. Turns out that is how Ringed Kingfishers hunt. They sit on an exposed perch, sometimes for up to two hours. They seldom hover like Belted Kingfishers (Brush 2009).

Seeing a Ringed Kingfisher surprised me. I thought that their United States range was restricted to the Rio Grand, and this impression may have been true when I first birded.  In the last 50 years, however, this species has expanded northward from Mexico (it also occurs well into South America). Now look at the eBird distribution map--the species occurs across most of southern Texas. Although their nesting biology is little studied, presumably Ringed Kingfishers' range are limited by their requirement of high dirt banks for nesting burrows.

Saturday, June 23, 2012

Blue-ringed Dancer

Blue-winged Dancers are found across most the the southern United States and south into Mexico. Erika and I found this one near its preferred habitat, a vegetation-edged stream running through San Marcos, Texas. Paulson writes that wide habitat tolerance contributes to its being relatively common and widespread. Keys to the identification of this damselfly include its mostly black body and blue rings and abdomen tip.

Friday, June 22, 2012

Great Kiskadee

During our March road-trip, Erika and I listed Great Kiskadees across much of the Rio Grand Valley. We did not get a decent photograph until our last day at the Salinero bird feeders. Found through most of Central and South America, kiskadees in the United States are found only in southern-most Texas. Their range in southern Texas is expanding.

Kiskadees flycatch for large insects, but also consume a broader range of prey than any other flycatcher--fish, tadpoles, fruits--even rice and dog food (Brush and Fitzpatrick 2002). Hence their presence at bird feeders. Kiskadees are aggressive, and will harass monkeys, raptors, toucans or snakes. They are noisy birds. We heard them before we saw them at Santa Ana National Wildlife Refuge. They exclaim, "kiskadee!", thus explaining their name.

Thursday, June 21, 2012

American Lady

A good field mark for the American Lady is the tiny white spot completely surrounded by orange on both forewings. This butterfly is common across most of the United States south South America. Two or three hatchings a year brings it, during some summers, into Canada (and even Europe). Erika and I found this one in Texas, where American Ladies fly year-round. Lepidopterists do not know if they survive the cold of Minnesota latitudes, where summer populations may have to be reestablished annually from southern parts of the range (Butterfliesandmoths.org). A wide variety of weed flowers sustain both the adults and their caterpillars.

Wednesday, June 20, 2012

Variegated Fritillary

In Texas this March, Erika and I saw a Variegated Fritillary. Note the black-ringed orange spot on each forewing: a distinctive field mark for this butterfly. These fritillaries are common across most of the southern United States (and south into South America). During some summers they spread north, even into central Canada. The larvae favor a number of plants, including flax and violets; adults drink from a wide variety of field weeds.

Tuesday, June 19, 2012

Great Spangled Fritillary

On Friday Erika and I visited Afton State Park in Washington Co., Minnesota. We happened upon this Great Spangled Fritillary, common along woodland edges across the northern United States and southern Canada. This butterfly is more abundant in the east than in the west and color varies across this range. Males emerge in May and June and survive only to mate. After mating, females remain under bark or leaves, coming out in August through September, at which time males are almost non-existant (Wikipedia). Although adults feed on a wide variety of flowers, females lay eggs on violets.

Monday, June 18, 2012

Review: Thayer Birding Software


I have always been a big fan of Thayer's Birding Software. Thayer Birding has released two interesting new editions of their software: Version 4.5 (For Widows XP, Vista, Widows 7 and Mac OSX 10.4 to 10.7) and Gold version 5.5 (for Windows XP, Vista, and Windows 7--BUT NOT FOR THE MAC, unless you run a Windows emulation program in your Mac.) Thayer provides free updates for birders who already own version 4.0 and Gold 5.0. Those of us with older versions need to purchase new DVDs.

This software is an incredibly robust tool for learning the birds of North America. When I taught ornithology, my students bought these DVDs in place of a normal textbook. Although the prices of these products seem expensive, most college textbooks cost more! In any case, the DVDs come with an imbedded 785-page copy of The Birder's Handbook. While perhaps not replacing a traditional ornithology text, this handbook, linked to individual species accounts, provides extensive bird biology.
These DVDs provide students with the ultimate set of flash cards for learning birds. Students can easily produce quizzes covering all birds, state birds, or even local birds. After using these quizzes, my students commented that identifying birds was pretty easy. I replied that most things become easy if you study as hard and as often as they did while using their Thayer bird quizzes. Bird calls included in this software can be transferred to iTunes, and thus used on cell phones, iPods or other MP3 players. 

There are many improvements among the various editions of these DVDs. You can check out the many features of these DVDs at Thayer Birding Software. The one that inspired this review, however, is the inclusion of over 600 photos of bird eggs and nests. This feature makes this resource all the more valuable for birders. Briefly, the Gold edition now contains 970 species and 3,431 photos. There are 719 bird songs and 552 video clips.  (Compare this to 702 species, 2,501 photos and 655 songs in version 3.9). In addition to more video clips, version 4.5 adds 53 new species from previous editions.
Don't be misled by my emphasizing beginners' learning birds with these DVDs. This software will be enjoyed by birders of all abilities. More advanced birders will enjoy identifying new birds, studying birds to be found during travels to new parts of the country, studying unfamiliar bird calls, and even keeping up electronic lifelists. For example, I used my Thayer Birding Software in south Texas to identify the Mottled Duck photographed below. I was able to pull up side-by-side comparisons of Mottled, Black, and Mallard ducks, facilitating the identification of this difficult species.

Sunday, June 17, 2012

White-tailed Kite

In the United States, White-tailed Kites are found in southernmost Florida, southeastern Texas and the West Coast. Strays occasionally occur as far north as South Dakota, Minnesota, and New England. This raptor is also found from Mexico south through Central and South America. Our populations were nearly extinct in the early 1900s. Numbers recovered after that but once again declined since 1980. Although this kite inhabits open grasslands, grassland conversion to agriculture and, surprisingly, the cutting of nest trees causes threats to its success. Furthermore, this kite prefers areas with sparse human habitation. Some population numbers fluctuate, but ornithologists do not know if the species is migratory, nomadic, or both (Dunk 1995).

The systematics of this kite are also confusing. Until relatively recently White-tailed Kites were considered to be the same species as the Black-shouldered Kite, found across much of the Old World. The American Ornithologists' Union, despite many similarities, recognized the two as separate species in 1993. Currently White-tailed Kites in South America are thought to be only racially distinct from larger North American birds. Two other similar kites are found in Australia and are classified as distinct species. Dunk (1995) warns that "until biochemical analyses are conducted on [these] kites, the taxonomy will likely remain in flux."

Erika and I saw but one White-tailed Kite during our March Texas visit. The bird obligingly waited for us to do a U-turn along a south Texas highway, jump out of the car, and take this photograph. Several years ago, we saw a White-tailed Kite in the California's Napa Valley, but never got close enough for a picture.

Saturday, June 16, 2012

Dickcissel

This year seems to be a good one for dickcissels in Rice County. During a recent stroll, Erika and I easily saw several in the Carleton College Arboretum prairie. I have previously blogged about this species' fascinating biology. Their distinctive call and plumage make the males easy to identify. Identification of the females, such as in the photograph below, can be more difficult.

The female is perched on White Wild Indigo, a common wildflower in the Carleton prairie. This plant is important  for a number of moths and butterflies, both for feeding adults and growing caterpillars. White Wild Indigo is, however, poisonous to mammals and can seriously poison livestock (Illinois Wildflowers). Because of prairie conversion to agriculture, this wildflower is listed in Minnesota as a species of Special Concern. The species is common in the restored Carleton Prairie and is often sold in native seed packets for home landscaping (Minnesota Wildflowers).

Friday, June 15, 2012

Pyrrhuloxia

What a strange name--Pyrrhuloxia. Apparently the name is derived from the Greek for reddish (pyrrhos) and for the bill shape (loxia). Another name is Desert Cardinal. Found in the southwest United States and northern Mexico, the Pyrrhuloxia is closely related to the Northern Cardinal. Their ranges overlap, but generally the Pyrrhuloxia is found in drier habitats.

We found a Pyrrhuloxia at the bird feeder in Salinero, downstream along the Rio Grand from Falcon Dam. In early March, when we visited Texas, Pyrrhuloxia flocks begin to break down as the males become aggressive and territorial. Curiously, where their ranges overlap, Pyrrhuloxia and cardinals do not show interspecific conflicts. Due to habitat destruction, Pyrrhuloxia numbers have declined in the past fifty years (Tweit and Thompson 1999).

Thursday, June 14, 2012

Black Tern


John H. and I canoed Sprague Lake in southwestern Rice County, Minnesota, on Tuesday. We found breeding Black Terns on this relatively pristine lake. Four pairs allowed us relatively close approach. We were surprised that they nested near the public access to the lake. Black Terns are known to nest "semicolonially." Since the 1960s, the numbers of this species declined by about 3.1% per year (Heath et al. 2009). Factors contributing to this decline include loss of wetlands and adverse affects of agricultural insecticides. This tern eats both minnows and flying insects, both of which can be adversely affected by the poisons.

Tuesday, June 12, 2012

Song Sparrow Bath



On a hot mid-day in the Carleton College Arboretum in Northfield, Erika and I came upon a Song Sparrow bathing in a puddle in a dirt road. Judging by the splashing, nothing suits a Song Sparrow better than a good bath on a 90 degree day. Even in colder weather, Song Sparrows are known to bathe frequently, at least once a day during the summer (Arcese et al. 2002).

Monday, June 11, 2012

Blue-tipped Dancer

Odonata Central is a robust website dedicated "to make available what we know about the distribution, biogeography, biodiversity, and identification of Odonata (dragonflies and damselflies) world-wide." A history of this project can be found at http://www.odonatacentral.org/docs/OdonataCentral2010Update.pdf. Odonata Central is a lot like eBird. I am such an amateur odonatalogist (I even had to make up the word odonatalogist), that I have never contributed to Odonata Central, except Scott K. will submit my noteworthy records after he verifies my identifications.

On Friday Erika and I biked the Cannon Valley Bike Trail from Welch Station to Redwing, Minnesota. Along the trail, at a bench set up to watch an eagle nest in the forest, we found about a half dozen dark damselflies. According to DuBois (Damselflies of the North Woods), no other North Woods damselfly has a dark thorax and a pale blue abdomen tip. Paulson (Dragonflies and Damselflies of the East) continues, this is our "only dancer with its combination of violet, black, and white thorax..."

For the first time in my short odonate-chasing career, I felt confident to try entering this record in Odonata Central. A check on the map for this species indicated that this species is eastern, with Minnesota lying on the northwestern extreme of its range.  Indeed, only three Minnesota records are included on the Odonata Central maps--in Goodhue, Rice, and Washington counties. Furthermore, the Goodhue record lacks a date or a precise location. The way Odonata Central works is that submitted records are checked by experts and then either accepted or rejected. Imagine my delight, a day after submitting my record, to find my discovery accepted!

Sunday, June 10, 2012

Altamira Oriole

As we headed out of Texas, we tried to find the Salinero bird feeders. I had only a vague idea that feeders existed near the town of Salinero, along the Rio Grand, just downstream from the Falcon Dam. I thought the feeders were near some trailer homes. Nobody I asked had a clue what I was talking about, not the convenience store manager on the main highway, or at the local fire station. We drove on deteriorating roads until we reached the river, where, hidden in the brush (but with a sign welcoming birders), sat a single trailer with a huge bird feeding station.

We faced a long drive across western Texas, so we could not spend much time at the feeders. We sat on lawn chairs with a half dozen other birders. We quickly saw an Altamira Oriole. The Altamira Oriole, also known as Lichtenstein's or Black-throated oriole, is common across most of its Mexican and Central American Range. In the United States, the species is only found in the southern Rio Grand Valley.

Unlike Minnesota orioles, the sexes of Altamira Orioles are similar. They are solitary nesters and are monogamous. Because their nests are pendulous, hanging from high, inaccessible branches or telephone wires, little is known about the life history of this stunning bird (Brush and Pleasants 2005).

Friday, June 8, 2012

Roseate Skimmer

The many ponds at the Estero Llano Grande State Park, in the Lower Rio Grande Valley, make the location excellent for dragonflies. During the cool, windy March that we visited the area, we only saw a few odonates, including this female Roseate Skimmer. This species is common across much of the southern United States, south through Chile. One reason this dragonfly enjoys such a wide range is that it is tolerant of a wide range of habitats. This skimmer lays eggs in a variety of aquatic habitats, sometimes even in very small pools. Aggressive hunters, Roseate Skimmers will take prey almost as large as themselves.

Thursday, June 7, 2012

Barred Owl and Bald Eagle

Last year I blogged about Barred Owls. On Tuesday Erika and I spotted another as we canoed down the Cannon River from Faribault to the Rice County Wilderness Park. With the weather warm and the wind to our backs, we enjoyed a delightful afternoon. We often hear and occasionally see Barred Owls along the river. This individual looks like a young bird, judging by the fluffy neck feathers and relatively ill-defined facial disk. Another clue is that the owl never left its perch as we canoed under it, despite an attack mounted by two angry male Rose-breasted Grosbeaks.
We also passed a Bald Eagle--a subadult, judging by the dusky color on the white tail. This bird also stayed on its perch as we floated underneath.  I seldom take my binoculars while canoeing. The Cannon River is a delightful canoeing River, with nary a class 1 riffle all the way from Faribault to the Mississippi. Nevertheless, I'd hate to watch my binoculars disappear into the depths. Tuesday was the first time I've brought a camera along--double-bagged in water-proof canoeing sacks. Patient were the birds that stood still long enough for me to unwrap the camera. (The dragonflies did not wait around to have their pictures taken.)

Wednesday, June 6, 2012

Harris's Hawk

On the advice of birders we met in the Lower Rio Grand Valley, We visited the Estero Llano Grande State Park. The park offers excellent birding and dragonfly opportunities. Among the birds, we found this Harris's Hawk. This raptor is found in scattered locations across the southwestern United States, from Texas to California, as well as Central and South America.

Harris's Hawks practice communal hunting, cooperative groups of up to seven individuals, including adults and subadults. (A photo of such a group can be seen at the Ecobirder blog site.) This behavior makes Harris's Hawks a favorite among falconers, as the hawk will easily team up with its human handler. Often in movies or on television advertisements, you can spot Harris's Hawks, regardless of the location of the film. They are often are the stars of raptor education programs.

Within these hunting groups, wild Harris's Hawks exhibit a wide variety of mating strategies--monogamy, polyandry (one female and more than one male) or polygyny (one male and more than one female). Hunting Harris's Hawks will successively attack prey, the birds' leap-frogging each other until the prey is caught. Often groups will surround a prey's hideout and then one hawk will flush the prey (Dwyer and Bednarz 2011).

Tuesday, June 5, 2012

Queen Butterfly

Another butterfly we listed at the National Butterfly Center was the Queen. Usually found in Mexico, Central and South America, and the southwestern United States, as well as coastal areas of the southeast, Queens do occasionally stray northward, even to Minnesota. They look a bit like Monarchs. Queens may be migratory like Monarchs, but their movements are not well understood. Like Monarchs, Queens seek out milkweeds. They require alkoloids in the milkweeds for breeding (Kaufman 2003), chemicals which also make them distasteful to many predators.

Monday, June 4, 2012

Brown Longtail

Another south Rio Grand Valley destination for us was the National Butterfly Center. Of the parks we visited, the Center was perhaps our least favorite. It was small, relatively undeveloped, and expensive. We did encounter several butterflies, but no dragonflies. A cloudy, cool March day was probably not the optimum time for a visit. We saw more birds than butterflies.
We did see a few butterflies new for us. One of these Lepidopterans was this Brown Longtail. This skipper is common in south Texas and coastal Mexico south through most of South America. The species' survival in southern Texas depends on refuges such as the National Butterfly Center (Butterflies and Moths of North America).

Sunday, June 3, 2012

Purple Martin


Erika and I photographed this male Purple Martin last week, during an extremely hot day, with temperatures above 90 degrees F.  The martin perched near a nesting box adjacent to the Lake Byllesby County Park in nearby Dakota County. The bird preened, sang, and occasionally either yawned or panted.

Martins are the largest North American swallow and few anywhere in the world are larger. Because of about a half dozen quite similar species in South America, ornithologists are uncertain of Purple Martins' migratory routes and winter range. Apparently the main wintering grounds are in Brazil and eastern Bolivia. Birds marked with ultraviolet paint in Sao Paulo, Brazil, nested in "Texas, Louisiana, Missouri, Wisconsin, Kansas, Virginia, Maryland, Pennsylvania, New Jersey, and Ontario" (Brown 1997). Despite my banding several hundred nestling martins in eastern South Dakota, I have never had a recovery.

Friday, June 1, 2012

Inca Dove

Inca Doves are another Mexican and Central American species moving north. Although currently seldom seen north of Texas, records even exist from the Dakotas. These far-northern birds may be escapes from migrant farm laborers. Inca doves, however, are not cold-tolerant. They are known to roost in a pyramid, up to a dozen birds in rows of two or three on top of one another.

Erika took this photograph at the Bentson State Park near Mission, Texas. The scaly appearance to the back and the long tail differentiate it from the Common Ground Dove, which we also saw in the area.