Sunday, July 31, 2016

Treefrog in the Garden

This tree-frog in Erika’s rose bush is may be a Gray Treefrog. The problem is that Gary Treefrogs can not be told from Cope’s Treefrogs, except by call.  But even the call is similar. The Gray’s call is slower than the Cope’s. This one was silent. Grays also have twice the chromosomes as Cope’s—no help here. Both species venture into urban areas.

Gray Treefrogs spend the winter partially frozen under leaf litter.  This frog’s liver coverts glycogen into glycerol, which prevents ice formation in their tissues. Some of their organs can also tolerate ice crystals. Some tropical treefrogs are among the most poisonous of animals. Skin secretions from Gray Treefrogs can be very painful if you get the secretions in your eyes, nose, or open sores (Savannah River Ecology Lab).

Friday, July 29, 2016

Swainson’s Hawk

A poor photo of a good bird in Rice County—a Swainson’s Hawk. This individual was first reported by Gerry Hoesktra, who saw it on several occasions this summer. After several previous searches, John Holden and I finally found it on Wednesday. It flew from telephone wires next to the road to a perch high in a distant oak. 

Over the years, I have seen a few in the county. This raptor is western, breeding in the Great Plains, from southern Canada to northern Mexico. Western Minnesota is normally as far east as this species breeds. Swainson’s Hawks winter in Argentina.  They form flocks during migration, a flight over 10,000 km each direction. An incredible 845,000 individuals have been censused during the fall migration over Veracruz, Mexico (Bechard et al. 2010). Although Swainson’s Hawks eat mammals, birds, and reptiles, perhaps one reason for these seasonal movements is their fondness for grasshoppers, dragonflies, and caterpillars—all abundant in the Great Plains and the Argentine pampas.

Thursday, July 28, 2016

Review: Birds of Peru App.

Birds of Peru App. Birds in the Hand, LLC. Version 1. 929 MB.  Requires iOS 9.0 or later.  Compatible with iPhone,  iPad, and iPad touch.

Peru, with over 1800 bird species, is a fantastic country for birders. In 2007, Princeton University Press published Birds of Peru by Schulenberg et al.  A second edition appeared in 2010. Princeton also sells a non-interactive digital edition. The Birds in the Hand app, which I am reviewing here, is an interactive version of the second edition.

Why buy the app if you already own the book? The number one reason is the inclusion of songs for 1510 Peruvian birds. These recordings are a treasure trove for birders. The plates and maps for each species are large and excellent. Thirteen of the world’s most famous bird artists contributed full-color portraits.

The app’s organization is straightforward. A menu bar takes you to a list of Peruvian bird families. The family list links to a species list that includes thumbnails of the birds of Peru. The effective use of these lists depends on the user’s familiarity with tropical bird families. The app includes options for filtering the list by the color, size, and habitat of what you are trying to identify. The result is a list of possible birds. You can even filter the list by the general region of Peru that you are visiting. Future editions will include a “nearby” option, showing what birds are found in your GPS area.

Other links on the menu bar take you to written discussions of field marks and habitats and to large range maps. Another link takes you to bird songs. Having separate links seems a bit clunky. Too bad the links are not next to the species’ plates. Perhaps there could be a thumbnail map next to each bird’s picture. As it is, the reader has to leave the plate to get written text or maps. A final link takes you to your life list, which you must manually enter (a shame you can’t import your eBird data).

Comparing similar species is hard since there is only one species per page. Instead you must depend on the tiny thumbnail portraits in the table of contents. Brief descriptions of field marks, perhaps linked to the descriptive texts, could be included with the large portraits. Once you know what you are looking for, searching can be expedited by using four-letter codes.

This app costs $34.99 at the iTunes Store.  Princeton’s non-interactive digital book costs $26.71 at Amazon. The paperback book is $28.12 at Amazon. Some may think that the digital price is high, but, when you consider the up-front development cost, the price seems reasonable.  The songs and the filtering capabilities of the app are worth the cost of the app. Nevertheless, a hard-copy book, for me, is easier for comparing species. Traditional books do not need recharging at the end of the day. Both formats are essential for anyone interested in the birds of Peru.
(I took this photo of a White-plumed Antbird in Peru in 1972.)

Tuesday, July 26, 2016

American Rubyspot

A male American Rubyspot flashing his red wings. On Sunday, Erika and I stood on a bridge in the Lyman Lakes area of the Carleton College campus. I told Erika, “three years ago, I saw American Rubyspots at this exact location.” As soon as I uttered these words, we discovered a single rubyspot perched on a twig in the middle of the creek. The damselfly made repeated forays from his perch, aways quickly returning. This behavior allowed me to take several in-flight photographs, of which, this picture is the best.

In a previous post, I wrote "The male rubyspot’s red wing spots grow larger over time, and are largest on dominant males. Paulson suggests that these spots actually decrease the most dominant male’s hunting success.” In my older post is a photograph of a male with less gaudy spots.

Monday, July 25, 2016

Forster’s vs Common Tern

I took the first photo at Chincoteague National Wildlife Refuge on 28 March. In the field, due to the white windows in the upper wing, I identified it as a Forster’s Tern. But when the file came out of my camera, I was less sure. The bill and feet seemed too red. On the other hand, I think I see a white leading edge to the outer tail feather—a Forster’s Tern field mark.

On 18 May, back in Minnesota, at Lake Byllesby, I saw three terns that were clearly Common. Look at the gray underparts that contrast with its white cheeks. Moreover, the outer edge of the outer primary appears to be black—clearly a Common Tern. I also became a whole lot more confident of my previous Forster’s Tern identification.

Sunday, July 24, 2016

Spot-winged Glider

On 15 July 2016, Erika and I walked in the Carleton College arboretum. We are quite a sight. Erika gets further and further ahead, as I squeak at birds and try to focus my camera on dragonflies. This situation is good, because she can spot dragonflies for me.

On this day, Erika stopped and pointed, “Come quick, there is a dragonfly hanging in the grass on the side of the path.” When I finally saw the dragonfly, I knew it was different. Look at the red eyes and the robust abdomen. I started at the baskettails, but quickly honed in on gliders. I have seen Wandering Gliders in the arboretum. But this glider did not look quite right. For one thing, its sides are brownish, not yellow.This photo proves that Spot-winged Gliders’ wing spots are not always visible. They adorn the base of the hind wings. I tried to maneuver to get a back-side view, but the glider quickly flew.

Spot-winged Gliders are found from Canada to Argentina.  In Minnesota, they are migratory. They winter in the south and appear here in summer. The larvae develop in only five weeks, before departing to warmer climates (Mead). Our record is the first for Dakota County (and a first for us, for that matter). A couple of records do exist from next-door Rice County.

Saturday, July 23, 2016

Black-shouldered Spinyleg

Erika and I came face-to-face with this Black-shouldered Spinyleg on 2 July 2016 in the Carpenter Nature Center (Washington County, Minnesota). I have only seen this species once before, in nearby Afton State Park on 19 August 2011. Because of the broad, dark bands on the sides of the thorax, I was fairly confident in my identification. The dragonfly flew and landed several times, always facing towards us, before it flew into the woods. In fact, later this same day, we saw another spinyleg at the state park.

This spinyleg is an immature. They become more dusky as they age. The spines on the legs, for which this dragonfly is named, are barely visible in this photo. Minnesota is on the western edge of the Black-shouldered Spinyleg’s eastern North American range.

Friday, July 22, 2016

Canada Warbler

Male Canada Warblers are among the most beautiful birds. I banded this one last May. These birds breed across most of Canada, southeast into Minnesota, Wisconsin and the northeastern United States, south through the Alleghenies to Georgia. They winter in Northern South America. We saw them in October and November in the Peruvian and Ecuadorian jungles.

Canada Warblers appear to be in trouble. Their population is often declining by more than 2 percent each year. Lumbering and loss of forested wetlands contribute to this problem. A glimmer of hope is that this species can breed, if enough trees remain in fragmented forests. But the warblers’ survival depends on vigilant habitat management (Reitsma et al. 2010).

Wednesday, July 20, 2016

Azalea sawfly

This May, a herd of Azalea Sawflies defoliated, but did not kill, Erika’s azaleas. I base my identification by their food choice. Actually two species of Azalea Sawflies exist. Although they are in different genera, they are so similar in the larval stage that they defy identification. The larvae develop into stingless wasps.

Azalea Sawflies feed until only the leaf’s mid-vein remains. Fortunately only one generation of sawflies appears per year. Aside from squashing them between your thumb and forefinger, by the time the larvae are as large as the one in my photo, there is not much you can do. Younger larvae do most of the damage. Soapy sprays can be used but, since you need a direct hit, tend not to be very effective. The remaining alternative is to use commercial insecticides (University of Minnesota Extension Office). (We used the thumb and forefinger technique.)

Tuesday, July 19, 2016

Powdered Dancer

Last week, on 12 July 2016, Erika and I encountered hundreds of dancers along a trail in the Carpenter Nature Center in nearby Washington County. I first identified them as Blue-fronted Dancers, but I was not completely sure. Later in the week, Facebook proved its worth when another contributor’s photo was corrected from Blue-fronted to Powdered Dancer. My photos are also Powdered Dancers. 
The first two photos are of andromorphs. These females look similar to males, but lack blue abdomen tips. The sutures between their blue thorax plates are wider than those of Blue-fronted Dancers. Elsewhere in this blog, I wrote that the apparent advantage for a female looking like a male is that competing males are less likely to hassle these females.
This third photo is of an immature male. Note its blue abdomen tip and the broad, pale stripe along the side of its thorax. In the field, I actually identified this individual correctly as a Powdered Dancer.
These last two photos are of female Powdered Dancers. The black lines on the thorax are too wide to be other species. These damselflies also lack dark sides to the ends of their abdomens. Thanks to Ed Lam for assisting me through Facebook with these identifications. Of course, I am ultimately responsible for the IDs made on this blog page.

Monday, July 18, 2016

Red-eyed Vireo

Banding is proceeding excruciatingly slowly this summer. On a sultry 11 July, I did capture this female Red-eyed Vireo. Blowing on her belly revealed a well-developed brood patch, so she is breeding in the backwoods. Females of this species build the nest, incubate the eggs, and spend more time than the males brooding and feeding young (Cimprich et al. 2000). Red-eyed Vireos are one of the most common woodland birds in eastern North America.

Sunday, July 17, 2016

Pied-billed Grebe

John Holden and I photographed this Pied-billed Grebe with her chicks last Wednesday at the 180th Street Marsh in Dakota County, Minnesota. With their red bills and white-striped faces, the chicks are kind of cute. Two chicks are not visible, making the total clutch size six. In Iowa, the mean clutch size is 6.2, ranging from two to ten (Muller and Storer 1999). Thus this bird’s number of young is what might be expected.

Saturday, July 16, 2016

Loggerhead Shrike

On 13 July 2016, John Holden and I found three Loggerhead Shrikes a mile west of the 180th Street Marsh in nearby Dakota County. Shrikes are always nice to see. They are found across much of North America, but, perhaps due to changing farming practices,  everywhere populations are declining.
These birds appeared to be an adult and two young.  The tan, upper wingbar in the first two photos indicates these birds are young. The bird in the middle picture appeared to be searching for prey. When one of the adults flew up and perched next to it, the young bird fluttered its wings, successfully begging to be fed. We could not see what it ate. These shrikes prefer insects, but also consume a wide variety of small vertebrates.

Friday, July 15, 2016

Atlantic Sunrise

We awoke in Virginia Beach on the morning of 28 March 2016. Fog and rain greeted us and lasted most of the day. On top of that, we had a cracked car window to repair. Our route took us across the Chesapeak Bay Birdge Tunnel. We made a short stop at Chincoteague NWR. The weather cleared, but we had little time.

I am not sure what is happening with this Turkey Vulture at Chincoteague. I do not know if the out-of-line flight feather was the result of molting or of being shot at.

Thursday, July 14, 2016

Southwest Prong Slocum Creek

March 26, 2016 found us in Havelock, North Carolina. The weather was cold and rainy. I took a short stroll in back of our hotel, but did not see much. The Southwest Prong of Slocum Creek proved to be kind of a spooky spot. The water was black. An empty liquor bottle and a blanket lay on the river bank. The forest was silent.

Tuesday, July 12, 2016

Chipping Sparrow

Here are a couple of Chipping Sparrow photos from this year. Both are from Minnesota. The first is from Rice County and the second from the University of Minnesota Landscape Arboretum. The first was taken on 15 May; the second on 6 June.

Chipping Sparrows are one of the most common birds across North America. One reason for this abundance is their tolerance for a wide range of habitat. They are found in open woodlands, forest edges—almost anywhere with a weedy patch. They even like urban yards and gardens.

Monday, July 11, 2016

Common Green Darner

Photographing flying dragonflies boils down to dumb luck. On Sunday, Erika and I visited the Northfield Garden Club’s annual garden tour. This Common Green Darner patrolled a water feature at one of the gardens. I only got one shot off, and to my amazement, the image is more or less in focus.

Elsewhere in this blog, I have written about green darners. They tend to be migratory and serve as a major food source for kestrels and martins. These dragonflies, in turn, consume mosquitos and other arthropods.

Sunday, July 10, 2016


We spent 25 March exploring Savannah, Georgia. As big cities go, Savannah is fascinating. Established in 1733, the city consists of 24 parallel park squares. Public buildings and churches are on the east and west sides of the parks, the north and south were reserved for private homes. “I beg to present you as a Christmas gift the City of Savannah,” wrote Sherman to Lincoln in 1864, breaking the general’s usual custom of torching Southern towns.

With its grid of parks, architecture, and Live Oaks, the city has an almost European air. “Almost” being the operative word. I doubt many European cities have mysterious lines in front of Paula Deen restaurants, that dezien of Southern fried, fat-landen food—at ten in the morning. We can only assume the woman sitting on the curb has just exited Paula’s.

I suspect that Europeans do not display their expertise in Dog Beers, although certainly not all are adverse to a morning beer. This city even has birds. We photographed this Carolina Wren as it sang in downtown Savannah.

Saturday, July 9, 2016

Blue Dasher 2

I have gazed into the eyes of many a Blue Dasher, but never one with such emerald eyes. 8 July 2016, River Bend Nature Center, Rice County, Minnesota.

Friday, July 8, 2016

Green Heron

As even casual readers of this blog must realize, lately I spend a lot of time chasing dragonflies. That is exactly what I was doing on 2 July 2016, when I came face-to-face with this Green Heron. This small heron is often hidden in marsh vegetation, but it is common across most of North America.

Green Herons stalk fish, invertebrates and amphibians. Unlike most birds, they sometimes drop various baits to entice fish to come close enough for the heron to grasp or spear. Bait includes feathers, pieces of plants, bread crumbs, mayflies, worms, and even plastic foam. Live bait works best (Davis and Kushlan 1994).

Thursday, July 7, 2016


On 29 June, John Holden and I visited the 180th Street March in Dakota County. This Killdeer greeted us with a distraction display. The plover walked up to us, turned around, and lifted its tail towards us. Then it spread its tail at an angle and dropped its wings on the road. Several fledglings ran about in the roadside grass. These birds are famous for their attention-getting broken wing act that draws predators away from their young. I have no images of the chicks, but here is one from last year.

Wednesday, July 6, 2016

Rose-breasted Grosbeak

My banding activities have slowed to less than a trickle. Finally, on 5 July 2016, I banded the first of the young birds of the year. The red underwing feathers, barely visible in this photo, indicate this Rose-breasted Grosbeak is a male. The striking red, white, and black breeding plumage will be more or less acquired from January into April.

Monday, July 4, 2016

Widow Skimmer

This series of photograph shows maturing, male Widow Skimmers. As they age, the wings become darker and acquire a white pruinescene. The first picture was taken on 12 June in the St. Olaf College Natural Lands. We encountered the next skimmer on 6 June in the Carleton College arboretum.
We found this last Widow Skimmer on 27 June near Red Wing, Minnesota. I noticed in Odonata Central that Goodhue County lacked a record for this abundant species. Erika and I easily rectified this cataloging omission. Scott King wrote me that searching for these skimmers was akin to picking “pretty low hanging fruit.”

Sunday, July 3, 2016

Blue Dasher

Last March, while at the Savannah National Wildlife Refuge, we saw Blue Dashers. These were our last dragonflies of our trip—days of rain and snow were to come. These dragonflies are common across most of the United States, except in the northern Great Plains. They do not like unvegetated shorelines. Blue Dashers are tolerant of poor water quality, a trait which probably contributes to their abundance.
We found this last Blue Dasher in June at the Lebanon Hills Regional Park here in Minnesota. 

Saturday, July 2, 2016

Black Horsefly

Dragonflying with Scott King is always entertaining. Scott is also aware of all of the other insects—like this Black Horsefly that we found at the Koester Prairie last Monday. This horsefly was a mind-boggling inch-and-a-half long.

Fortunately Black Horseflies do not usually bite people. It hurts like hell if they do. Perhaps worse, their bite can transmit bacterial, viral, and protozoan diseases—such as anthrax or Trypanosoma. These horseflies pose serious threats to livestock (

Friday, July 1, 2016

Western Red Damsel

For some time, I have been telling Scott King, my dragonfly guru, about the spring in the Koester Prairie (Prairie Creek Wildlife Management Area). This grassland is fairly pristine, and the spring runs all year. Scott said, “This sounds perfect for finding Rice County’s first record of the Western Red Damsel.” I had to agree, despite my seeing this damselfly only twice before. Red damsels love marshes. Their small size and their reluctance to leave the vegetation make these damsels hard to see.

We immediately found dozens of red damsels, male (upper photo) and female (lower photo). The taxonomy of these little creatures is a mess. Western Red Damsels are found in the western United States. Eastern Red Damsels are found in the east. Red damsels from Indiana to western Colorado and from southern Saskatchewan to Missouri and Kansas are intermediate in their field marks.

Three solutions exist for this problem.

1. Recognize three species.

2. Call Eastern and Western Red Damsels just Red Damsels, recognizing but one species.

3. Ken Tennessen studied this problem and reported to the Dragonfly Society of America. He concluded that there are but two species. Characteristics used to separate the two species include “the ratio of hind femur length to abdomen length, setal color, and hind femur color pattern.” Unfortunately, the abstract describing his work does not include details. Tennessen does write that the red damsels in Wisconsin are Eastern. But Hummel writes me (pers. com) that Tennessen identified Hummel's Iowa damsels as Western. Scott King tells me that all his Minnesota records are also of Western Red Damsels.

Without further input from the experts, comparing my photographs from those on the Internet, I suspect mine are Western Red Damsels. Note the white tips to the male’s abdomen. This color is obvious on Internet photos of Westerns. On the other hand, if my photos are of Eastern Red Damsels, I will add a new species to my Odonata list.