Thursday, August 30, 2012

Black Saddlebags

In a previous post about Black Saddlebags, I mentioned that these dragonflies are seldom seen perched except in the treetops. This individual hung low in the undergrowth, allowing Erika and me to get quite close at the Ritter Farm Park in Dakota County, Minnesota. We were surprised by the blue stripes on the thorax and the amount of yellow on the top of the abdomen. These markings are probably the signs of a young female. In this photo, you can clearly see the large dark splotches on the hind wings that give this species its common name.  Paulson (2011) reports that Black Saddlebags are migratory here in the north, prefer to mate near lakes, and, as they deposit eggs, are often taken by bass.

Wednesday, August 29, 2012

Anna's Hummingbird

Because the Anna's Hummingbird thrives in urban settings, its range has expanded since the 1930s, when it occurred from northern Baja California to San Francisco. Now it reaches British Columbia and Texas. Last March, Erika and I found this individual along the northern California coast. This bird is named after the duchess of Rivoli. She and her husband owned the original specimens, which were collected by Lesson in 1829.

Although hummingbirds are not songbirds, this species' songs are "learned and complex" (Clark et al. 2012). As the males sing, they turn their heads from side to side, thus flashing their brilliant red heads. Females defend feeding territories separate from males. Pairs associate only to copulate--the female then makes the nest, incubates the eggs, and feeds the young.

Monday, August 27, 2012

Oak Titmouse

On our March road-trip, after leaving Morro Bay, we began to dodge stormy weather. During our visit to the Seal veiwing rest area described in my last few posts, we had to backtrack--the California Coast Road was blocked by landslides. The weather inland was balmy.

We found this Oak Titmouse at a picnic area along Lake Cachuma, northwest of Santa Barbara. These titmice mate for life, defend territories all year, and never make flocks as do other chickadees and titmice (Cicero 2000). They quickly responded to our squeaking noises.

Until recently, Oak and Juniper titmice were thought to be the same species, the Plain Titmouse. Recent genetic evidence concludes they are two species, with the Juniper Titmouse inhabiting dry interior junipers and the Oak Titmouse nesting in oaks and pines along the Pacific Slope of California.

Sunday, August 26, 2012

Water Lilies

Inspired by a recent Star Tribune article on the Lebanon Hills Regional Park that reported that this Dakota County park is a touch of the North Woods, Erika and I hauled the canoe on top of the car and explored. We had a good time following a paddle and portage route across about a half-dozen small lakes linked by quarter-mile portages. Except for power lines and the unceasing roar of aircraft landing and taking off from the Minneapolis/St. Paul airport, we were almost up north. We would not recommend a weekend visit, when it must be crowded, but we saw few people on Friday.

Highlights included White and Yellow water lilies, common on many Minnesota lakes. Yellow Water Lilies are usually found in more shallow water than White Water Lilies.  The Ojibwa ate cooked White Water Lily flower buds and made tea from the roots, which was said to combat diarrhea.  The root was also "used as a sore throat gargle, a cure for baldness, and a  lotion for boils, sores, and ulcers..." (Walshe 1980). White Water Lilies are food for moose and beavers (Moyle and Moyle 2001). The yellow species also was exploited by native peoples, who used rhizomes for ulcers and broken bones, and drank tea to combat a wide variety of ailments, including heart problems, asthma, and tuberculosis (bcadventure.com). Naturally, gentle readers, I advise against trying folk remedies and I take absolutely no responsibility for those who do.

Saturday, August 25, 2012

Brewer's Blackbird

As we left the Seal Observation Rest Area along the Coast Highway (see previous posts), a Brewer's Blackbird called goodbye. This blackbird has an interesting nomenclatural history. Audubon collected several in 1843 along the upper Missouri River. Thinking the birds were new to science, he named them Quiscalus breweri. Thomas Brewer was a Boston physician and ornithologist. However, Johannes Wagler first published a description of the species in 1829, naming it Psarocolius cyanocephalus. The Law of Priority kicks is applied to cases like this one. The correct name is the first published one, starting with Linnaeus' 1758 12th edition of his book, Systema Naturae. Thus Audubon's scientific name is no longer with us, but his common name, Brewer's Blackbird, has survived (Martin 2002).

Prior to 1914, Brewer's Blackbirds were a western species, not found east of western Minnesota. During the next 40 years, this blackbird expanded its range east (at least 1200 km) and north (some 300 km). Conversion of forest to agricuiltural land is cited for the reason. Now the species is common in the winter in the southeastern United States (Martin 2002). Brewer's Blackbirds and Common Grackles compete where their ranges overlap. Apparently Brewer's Blackbirds prefer grasslands, whereas grackles thrive in urban situations.

Friday, August 24, 2012

White-winged vs. Black Scoter

Near the Surf Scoter of the previous post, Erika and I found this male White-winged Scoter. Identification of White-winged Scoters is usually fairly easy--if you can see the white wing patch. That was not the case in the second photo, taken at Sand Lake National Wildlife Refuge near Aberdeen, South Dakota or in the third photo. The white patch was very difficult to discern, and we had to rely on the round shape of the anterior white face patch.
I took the third photo at Lake Oahe several years ago. The bird on the left is a White-winged Scoter, again with the white wing patch not visible. But the shape of the anterior face patch is round, not vertical as in a Surf Scoter. The right bird has a smaller bill and is clearly smaller bodied. Note the white cheeks, This duck is a female Black Scoter.
Black Scoters breed in Alaska and northern Quebec and winter off both coasts of North America. White-winged Scoters have a similar winter range, but breed from Alaska through the Canadian prairies. In Minnesota, the three scoters are "uncommon to rare migrants on Lake Superior, more often in the fall" (Eckert). White-winged Scoters are most often observed. The three scoters are rare fall migrants elsewhere in the state.

Thursday, August 23, 2012

Surf Scoter

In the surf at the Seal Rest Stop along the California Coast Highway, swam a female Surf Scoter. She is recognized by her two patches of white on her head head. The anterior patch is vertical, not rounded. A few days later, along the Oregon Coast, we photographed an adult male Surf Scoter (see lower photo).

Surf Scoters breed on arctic North American freshwater lakes and winter along both coasts, south to Baja California and Texas. Unlike the other two scoters (Black and White-winged), the Surf Scoter is only found in North America. Until recently, little was known about Surf Scoter breeding biology. Females with broods are not territorial but are defended, nevertheless, by their mates. On crowded lakes, broods get mixed, and young are occasionally raised by step-parents (Savard et al. 1998).

Wednesday, August 22, 2012

Connecticut Warbler


Last Monday morning I banded a young Connecticut Warbler. Although the Minnesota Ornithologist's Union considers this species to be "regular" in Rice County, this bird is only the second of the species I have seen here (see blog post of 14 September 2010). The record is noteworthy enough to appear on Jack Siler's eBird Rarity Map, a website I discovered only today.  Here you can see where all the uncommon birds are being seen in the United States. Click on the little Google Map pins and see what rare birds are being seen! The map is updated daily. 

Connecticut Warblers nest in boreal forests across central Canada, dropping south to breed in northern Minnesota and Wisconsin. They are shy and inhabit boggy thickets. These warblers winter in northern South America in the Amazon Basin. Note the tick embedded on the upper left quadrant of this warbler's eye-ring. Perhaps the tick will hitch a ride to South America.

Tuesday, August 21, 2012

Black and Yellow Garden Spider

While picking raspberries at our Community Assisted Agriculture farm, Erika came upon the Black and Yellow Garden Spider (also called Black and Yellow Argiope). These spiders are usually common from southern Canada to Costa Rica. They are found in gardens and fields. Like all spiders, they are venomous predators (University of Michigan). Their bite, however, is said not to be dangerous to people, perhaps no more than a bee sting. (I have been told, however, that bees kill more people through anaphylactic shock than do all other wildlife in America.)

This spider bites and eats smaller arthropods that become stuck in the spider's web. The female's carnivorous habits are a problem for their males, who are much smaller than the female in these photographs. Another problem is that this spider has poor vision. Not wishing to become dinner, males will often vibrate the edges of the web to announce their identity. It is almost (but not quite) like a suitor playing a love song on a guitar.

Monday, August 20, 2012

Surfbird

Erika and I did not visit the Elephant Seal Rest Stop on the California Coast Highway to see seals. I was chasing my number one nemesis bird, the Rock Sandpiper. A nemesis bird is one that eludes you regardless of effort. For years I searched for Rock Sandpipers along the rocky shores of the Pacific Ocean. This year, armed with eBird, I tried again. According to eBird, a Rock Sandpiper had recently been seen at the seal stop.

No Rock Sandpipers. Instead we found Surfbirds among the rocks. We were disappointed, despite the Surfbird's being an interesting sandpiper. This species has one of the longest but narrowest range of any North American bird. Surfbirds winter from Alaska to Chile, over 17,500 km, but only within the first few feet of the tide line. Early ornithologists were incredulous when Alaskan natives told them that Surfbirds breed on Alaskan mountaintops. One hundred and fifty years elapsed before searchers found the first nests in 1927 in the mountains of central Alaska (Senner and Mccaffery 1997).

Sunday, August 19, 2012

Canada Warbler

On Saturday I banded the first two Canada Warblers of the fall. (These photos were actually taken last year.) This species molts into prebasic plumage before fall migration begins. Thus, in contrast to many other fall warblers, Canada Warblers are often brightly colored. 
A lot of variation and overlap in color intensity, however, exist between both fall male and female, first-year and adult birds. Individuals with indistinct breast stripes are not necessarily females.
The species breeds in forests across central Canada and eastward to the northern Great Lakes states, New England, and the maritime provinces, then south through the Appalachian Mountains. Canada Warblers are usually not difficult to find as they migrate through southern Minnesota and nest in the northern forests of the state. Nevertheless, population numbers are declining about 2% a year (Reitsma et al. 2010). Forest clearing in both its breeding range and in the eastern Andes, which is the winter range, is likely a major reason for this decline.

Saturday, August 18, 2012

Elephant Seal

In March, after visiting Morro Bay, California, Erika and I continued up the California coast. Just a couple of miles north of the Hearst Castle, along The Pacific Coast Highway, lies a rather inauspicious rest area along the rocky cliffs looking over the ocean. A small sign advertises "Elephant Seal Viewing Area." This area is well worth the stop. Hundreds (and sometimes thousands) of these huge pinnipeds congregate on the beaches below the cliffs. The seals spend most of their lives at sea, coming to shore only to molt, give birth, mate, and, in this case, power nap (California Parks).

In the 1800s, Elephant Seals were almost exterminated for oil made from their blubber.  By 1892, fewer than 100 survived off Baja California. In 1922 the Mexico protected these seals, with the United States following a few years later (California Parks). The seals recovered, and, surprisingly, came to this roadside rest in 1990. The breeding season is from December through February (Amwest.travel). Noisy males fight for harems. Females arrive and give birth to young conceived the previous year (the fertilized egg delays implanting on the uterine wall for four months). After birth, the young gains almost 300 pounds in less than a month. Some pups nurse from two or three females. By April, most females and young migrate northwest to the coasts of Washington, British Columbia and Alaska. From July through August, only molting males are likely to be found at the seal beach.

Thursday, August 16, 2012

Common vs. Red-throated Loon

We visited the Morro Bay State Park January 2008 and had such a great time birding, Erika and I stopped there last March as we began our trek up the California coast. In March we saw fewer birds than we did in January. Two basic-plumaged loons greeted us at the park marina. Because the eye is completely surrounded by white, I decided the first bird is a Common Loon. The second bird is a Red-throated Loon. The best field mark here may be the white spots on the back. I also noted the slightly up-turned bill. Of course, we Minnesotans are familiar with  Common Loons. Red-throated Loons are also occasionally observed off Duluth and even more rarely elsewhere inland. This loon breeds in Alaska and across the Canadian Arctic, and winters off both coasts of the United States.

Some year I would like to attend the Morrow Bay Winter Bird Festival. The festival dates this coming winter are 18-21 January 2013. Not only would one list a plethora of bird species, I am sure birders of every ability would learn a lot about bird identification.

Wednesday, August 15, 2012

Dragonfly Book and Water Mites

I have written a book called "Two Years Among the Odonates." I describe the dragonflies and damselflies I have encountered during my first two years of odonate watching. Most of the material has appeared in this blog. The book is published by Blurb.com. Anyone interested can click on this link and see a 15-page sample of this 164-page book. Those wishing to purchase the book have choices in format (hardcover, softcover, etc.) and prices. Unfortunately the book is relatively expensive since it is produced on a per-order basis and it is all in color. Orders are processed quickly. I put another link to the book at the top of the right-hand column of this blog. Note that the book is also available at a greatly reduced price as an eBook on iBooks for the i Pad.

A few days ago I blogged about not finding water mites on my dragonflies. This lapses has been remedied by eagle-eyed Scott King, who spied a parasitic water mite larva on a photo I have previously posted. Look closely at the bottom (dorsal) edge of this Cherry-faced Meadowhawk's thorax (body). Another larva is attached on the bottom end of the abdomen (tail). Sometimes huge numbers of larva infest a single host.
Water mites are the only truly aquatic spiders. Adults are round, often red, with eight tiny legs. They are often abundant in lakes. A complicated vocabulary describes the mite life cycle. Basically, the adults, who are predators of various immature aquatic insects and micro-crustaceans, lay eggs in the lake.  The eggs develop into the parasitic larva that attach to a variety of insect orders, including flies, beetles, and dragonflies. These parasitic larva obtain nutrition from their hosts, but, perhaps more importantly, they are dispersed to new ponds and lakes. Once in the new habitat, the larva continue through a second form that resembles the adult but which do not reproduce. Finally the adult stage is reached and the little arachnids breed. For a more detailed description of the water mite life cycle, see "Water Mites of North America."

Tuesday, August 14, 2012

Bewick's Wren

At the Pismo Beach Butterfly Grove last March, Erika and I also photographed a Bewick's Wren (pronounced like the car). Years ago this wren was common across most of the United States, but has almost disappeared from the East. Now it is most common in southeastern Arizona, central Texas, and southern California. The reasons for this decline are not understood, but may include agricultural pesticides or competition with Starlings, House Sparrows and House Wrens. House Wrens have increased while Bewick's Wrens declined. Now many pale Carolina Wrens are misidentified as Bewick's Wrens. Bewick's Wrens were named by Audubon for his friend, the British engraver Thomas Bewick (Kennedy and White 1997).

Monday, August 13, 2012

Orange Bluet

This pair of Orange Bluets steadfastly maintained their wheel position on the side of the dock at the public access area on the north shore of Circle Lake in Rice County Minnesota. You may recall that, in this position, the female fertilizes her eggs with the male's sperm, while the male grasps her by her hind neck to assure no other males attach to her and replace his sperm with their own.

Male Orange Bluets (the one on the left) are readily identifiable. DuBoisassures us that the "tiger-stripe coloration of the male is unique among damselflies" of the North Woods. Females are not so easy: they are not always orange, but can have blue, green, or yellow stripes. DuBois also mentions that this species emerges and is most abundant later in the summer than the other bluets. I found this pair on the afternoon of 11 August 2012. This species is known to prefer the late day, even into dusk. Midday censuses may miss this damselfly (Paulson).

Sunday, August 12, 2012

Swainson's Hawk

On Saturday, 11 August 2012, Gene Bauer and I birded at Circle Lake in Rice County, Minnesota. We were delighted to find a Swainson's Hawk circling above the east shore of the lake. The raptor then flew off towards the north. I took the top photo that clearly shows the proper field marks for an adult Swainson's Hawk: dark chest, black flight feathers, and a somewhat pointed wing silhouette.
The second photo is of a bird found in eastern South Dakota several years ago. This bird breeds primarily in the Great Plains of the United States and Canada. In summer they are occasionally found along the western and southern borders of Minnesota. Swainson's Hawks are prairie birds. When breeding, although feeding their young rodents, rabbits, and reptiles, this hawk consumes almost only grasshoppers! Perhaps not coincidentally, after breeding, flocks of Swainson's Hawks begin a 10,000-kilometer migration to the Argentine pampas. Each fall, nearly a half-million individual hawks have been counted as they migrate over Mexico and Central America. Swainson's Hawk populations are declining. Radio tagging studies suggest that this decline is due to collateral pesticide poisoning in Argentina (Bechard et al. 2010).
I took this last photo near Aberdeen, South Dakota. This Swainson's Hawk is carrying a Tiger Salamander. None of my sources mentions amphibians in the lists of this hawk's prey items. Swainson's Hawks, despite their fondness for grasshoppers, must be opportunists when it comes to what they eat.

Saturday, August 11, 2012

Bicolored Blackbird

While at the Monarch Grove near Pismo Beach last March, Erika and I noted that the local Red-winged Blackbirds lacked yellow under their red epaulets. These birds are a distinct race of the Red-winged Blackbird found in the Central Valley of California. They are called Bicolored Blackbirds, Agelaius phoeniceus californicus. According to Yasukawa and Searcy (1965), the loss of the yellow color in the Red-winged Blackbird may be a species-isolating mechanism to keep this race from interbreeding with the Tricolored Blackbird, which also occurs in the region.

I have long wondered about the derivation of the Red-winged Blackbird's species name, phoeniceus. Grusonwrites that the word comes from the Latin for deep red, in turn originating from the Greek for Phoenician. Apparently the Phoenicians introduced the color to Greece. Gruson continues, "the...root of the word is 'to slay,' and thus create the blood-red color."

Friday, August 10, 2012

Sachem Skipper

Grass skippers are told by the way they usually hold their wings--the forewings up and the hind wings further down. This "jet plane position" is unique to the group (Kaufman).
Species identification is more problematic. Bugguide says success depends upon your being a wizard!  Nonetheless, identification here in Minnesota is not too difficult. These photos, taken in Erika's garden in early August 2012, are Sachems. The male's black stigma visible as a black splotch on the top of the upper wing in the second photo is diagnostic among Minnesota grass skippers. Wisconsinbutterflies says that the male Sachem is unmistakable. 
Females, like that in the third photo, are dusky below, not as bright as other species. A diagnostic field mark is that black square on the lower part of the underside of the hind wing. You can see that mark in the photograph.
Sachems are found in most of the United States and Mexico. The species does not breed in the far north, but spread north, even into southern Canada, during warm summers. They do not survive most Minnesota winters, thus, every year, they have to repopulate our area. They are common in gardens, parks, lawns and roadsides, in fact in almost any open area. Adults flit about, males often chasing females, and feeding on fall flowers; the larvae feed on grasses.

Sachem is an Algonquin word for leader. Sachems, unlike chiefs, were hereditary and ruled by consensus. New York City's Tammany Hall called its local leaders Sachems. Sachem came to mean a boss (Cirrusimage.com).

Wednesday, August 8, 2012

Cooper's Hawk vs. Goshawk


During a recent stroll in the Carleton College Arboretum, Erika and I spied the Cooper's Hawk in the upper photo. The yellow eye and striped underparts indicate the bird is juvenal. Adults have orange eyes and underparts with reddish bars. Our hawk was really large, clearly not the much smaller Sharp-shinned Hawk. Females of both hawks are larger than their males, but there is no overlap in size between species. The breast stripes are not course. Finally, note that the outer tail feathers are clearly shorter than the middle ones. Sharp-shinned Hawks' tails are relatively square-ended.

What about a Goshawk? The photo below was taken in a residential yard in Aberdeen, South Dakota. It is also a juvenal--note the yellow eye. Goshawks are larger than Cooper's Hawks, though it is hard to tell that in two photos. The Goshawk's tail bars are very uneven--note the relatively thin the dark bars--and compare them to the more evenly spaced tail bars on the Cooper's Hawk. The best field mark for a Goshawk is the white eye stripe. The stripe on a Cooper's Hawk is buffy at best. Finally, though hard to see in these photos, the Goshawk's underparts are more buffy than those of a Cooper's Hawk.

Tuesday, August 7, 2012

Townsend's Warbler

Near Carlsbad we drove over to Pismo Beach where we hoped to see over 23,000 Monarch Butterflies in a tree grove at the edge of town. Unfortunately, the butterfly season is from late October to February (monarchbutterfly. org). We were there in late March, and not a single Monarch was to be seen. On the other hand, we missed the 60,000 visitors who flock the the grove in season.

We were rewarded, however, with several interesting birds. Townsend's Warblers breed in northwestern North America and winter along the Pacific Coast of the United States and in Mexico and Central America. In California, this warbler probably gleans insects from foliage and frequents bird feeders offering a variety of food items (including cheese, marshmallows, and peanut butter). Further south this bird "exploits honeydew excreted by sap-sucking insects" (Wright et al. 1998). These scale insects are often injured as the warbler feeds on the sap at the tip of insects' anal tube.

Monday, August 6, 2012

Band-winged Meadowhawk

When I photographed this Band-winged Meadowhawk during my recent Saffron-winged Meadowhawk search, I thought I captured parasitic larval water mites. These aquatic arachnids have a fascinating life cycle. The larva attach to a variety of hosts, including dragonflies, and are thereby able to disperse from pond to pond. But--what a disappointment--I appear to have captured dragonfly excrement. On the other hand, how many people have actually seen dragonfly excrement? You can say you saw it on this blog!

Sunday, August 5, 2012

House Finch

Although most male House Finches are brick red, pale yellow and bright orange ones occasionally appear at local feeders. This yellow variant was at the The Flower Fields of Carlsbad, California, when Erika and I visited last March. Yellow color is the result of beta-carotene, while red is produced by echinenone. More yellow birds are noted in areas where natural foods are low in echinenone or when ornamental plants have high levels of beta-carotene (Project Feeder Watch).

Saturday, August 4, 2012

Yellow-bellied Flycatcher

Yesterday, 3 August 2012, I banded my first fall migrant--this Yellow-bellied Flycatcher. I knew that this flycatcher is an early migrant--it breeds in close-by northeastern Minnesota--and is a common breeding bird across Canadian forests. Most migrate from mid-August through early September. I was surprised to read in Janssen (Birds in Minnesota) that the earliest migration dates in southern Minnesota are throughout July. One reason for this early migration is that Yellow-bellied Flycatchers have one of the shortest breeding seasons of any neotropical migrant in the North Woods--often less than 70 days (Gross and Lowther 2011). This flycatcher winters in Central America. See also my previous posts concerning this species (8 September 2011 and 24 August 2010).

Friday, August 3, 2012

Horned Lark

After reading about The Flower Fields of Carlsbad, California, Erika and I visited as we drove along the Coast Highway. Although we were somewhat disappointed to discover a monoculture of giant Ranunculus, we enjoyed our stop. I did manage to see a couple of interesting birds. The first were a few Horned Larks that allowed close approach.

In Europe and Asia, this species is found from the arctic to North Africa; in the Americas, it is found from the arctic through Mexico, with an outlying population in Columbia. Horned Larks are extremely variable across this huge range. Twenty-one subspecies have been described from the New World. (See how different a Minnesota bird's eye stripe color is compared to this California bird.) Color tends to match local soil color. Western races tend to be smaller and paler than northeastern ones. Migratory races have longer wings than sedentary subspecies. Desert birds tend to have longer legs than those from cooler areas. Where their ranges meet, most of these races interbreed. Perhaps signifying New and Old World races are separate species, Siberian and North American races overlap but do not interbreed in the Aleutians (Beason 1995).