Silver Gull

I once considered keeping a life list of birds seen at the movies or television. The rule was that the show could not be about the bird in question. The bird's appearance had to be unintended. One of the birds on my movie/tv list was a Silver Gull, one of the most common Australian gulls. One flew behind racing sloops at the America's Cup at Perth, Australia. The species earned a place on my regular life list when I found this gull as we both strolled on the promenade in front of the Sydney Opera.

This gull's age can be judged by the intensity of the red on their bills--the brighter the red, the older the bird (Wikipedia). I assume this bird is relatively young. Obviously this gull has adapted to urban environments. They scavenge and thus thrive at malls and garbage dumps. At least twice, Silver Gulls have been seen in North America (in New Jersey and New York) but these birds are assumed to be escapes from captivity. Normally the species is restricted to Australia and New Caledonia.

Book Review: Dragonflies and Damselflies of Texas

The full title of this book is Dragonflies and Damselflies of Texas and the South-Central United States. This area includes Texas, Louisiana, Oklahoma, and New Mexico. Thus the book covers a huge region often visited by dragonfliers and birders.

This audience for this book is probably folks who are not rank beginners. The book includes color photographs of almost all the species. The photographs, however, are relatively small and do not have arrows or text pointing out salient field marks. Most disconcertingly, the photos only indicate the location where the photo was taken and does not direct the reader to the appropriate pages for species accounts in the text. The computer-enhanced illustrations in Abbotts' Damselflies of Texas are far superior. But the damselfly book does not cover dragonflies and is limited to Texas.

The text is well-written and organized. Unlike many other dragonfly books, keys to the species, genera, and families help the reader note the critical field marks of each species. The accounts include size, regional and general distribution, flight season, identification, similar species, habitat, a short discussion, and references. Clear maps, showing counties where each species has been found, accompany each account. One assumes some of the blank spaces are simply unstudied counties. Also illustrated are odonate backends (often critical for correct species identification).

The introduction is short, only 14 pages, but covers a great deal of information. Habitat and zoogeography are discussed and are important, since the range accounts often refer to the biotic provinces of the region. Odonate life history and seasonality are covered. A few paragraphs on photographing odonates conclude that you should bring with your equipment "a healthy dose of patience."  Finally the introduction presents detailed drawings of various aspects of anatomy.

The book ends with a checklist of species and an extensive bibliography. The bibliography is to be expected in a book directed at professionals needing to identify odonates.  Indeed, Abbott occasionally refers to "this study found," which indicates the origin of the book may have been a dissertation or other scholarly work. Nevertheless, one of Abbott's goals is to pass along "as much natural history and other biological information about each species as possible."

The book covers 263 species, making somewhat more manageable than Paulson's Dragonflies and Damselflies of the West, with its 348 species. The keys to the species make Dragonflies and Damselflies of Texas indispensable for the dragonfly enthusiast.

eBirdGM—Inserting Maps into eBird

This app is found on BirdVenture.  It enables you to embed Google Maps into your eBird lists. Go to BrdVenture to use the app. This would be helpful like when you see uncommon birds (like my very early Red Crossbills last summer in Dakota County) and you want to lead others to the location.

The directions from BirdVenture are simple:

1. Go to Google Maps
2. Zoom in on your precise location (or search for it)
3. Right-click exactly at that spot, and select "What's Here?"
4. Copy the Latitude-Longitude coordinates that appear in the search box

Then click the “Get Code” button and you should generate some code to paste into eBird.

Go to eBird.  Click on the Add Details button in your bird list.  Paste in the code that you copied from eBirdGM.  Save the file.  The map should appear on your list.

Biographical eBird Map (eBird LifeMap)

This frigid, icy weekend my get-up-and-go got-up-and-went (to more or less quote from an American folk song), and I found myself bird-surfing the WEB. I stumbled upon the eBird LifeMap. This app converts your eBird data to a Google map, connecting your locations by date of observation with red lines. The result is a birding travel log. I will provide you with a link to this WEB site at the end of this post.

I assume you are familiar with eBird. Last year I entered almost all my bird records into eBird, beginning from 1960 when I was a 13-year-old. The records fall into three categories: life list records, miscellaneous birding lists, and current eBird submissions. The compilation of these 35,053 records can be seen in this first map.

Life-list records tend to give you the cleanest trip routes. But the routes are not always precise. Note the jags across the map of North Dakota. Erika and I drove staight across the state in 1968. I think what is happening here is that birds were seen on the same day but the computer has no way of knowing which species was seen first. A larger anomaly is the red line heading north out of the Galapagos Islands on the World map. You can only fly into the Galapagos from Ecuador. What happened here is that I left the islands, spent the night in Quito, and then returned home. The next new bird I saw was several months later in South Dakota. Thus a straight line exists between the Galapagos and South Dakota. The overall map, although not completely accurate, does give a satisfying representation of my birding career. A more practicable use for these maps might be to spot date or location errors in your eBird reporting.

The final map depicts my birding in the Minneapolis Metro Area. This map includes a year or so of almost daily eBird submissions (and no life birds). Clearly Northfield is my center of operations. The odd, comet-tail patterns at the top of the map are due to 20-years of commutes into the Twin Cites from South Dakota for birding and culture. Another possible cause of these patterns is that some of those early lists are of county birds rather than of specific locations. 

You can build your own eBird LifeMap by following the instructions at the Birdventures website.  This process is relatively simple but geared to the PC computer. Because I own a Mac, I had a bit of trouble. I e-mailed developer Zachary DeBruine for help, and was amazed by his prompt and patient responses. (You do not have to use all your eBird records. You could use, for example, the records from one summer’s travels and generate a map of those trips.)

The eBird LifeMap is not the only eBird mapping app available from Birdventures. In my next post I will review their eBird GM app that allows you to embed Google Maps directly into eBird files.

Baltimore vs. Bullock’s Orioles

While reviewing my blog, I am surprised how little I have had to say about Baltimore or Bullock’s orioles. These species are common across North America, with the Baltimore (above from Minnesota) breeding in the East, and the Bullock’s (below from Arizona) in the West. Across the Great Plains, where their ranges overlap, the two species interbreed—even though, as you can see in these photos, the two populations look quite different.  In 1983, citing this hybridization, ornithologists merged the two populations into a single species, the Northern Oriole.

Much to the delight of North American bird listers, the merge of the Baltimore and Bullock’s orioles only lasted a little over a decade.  During this time a number of discoveries were made. The zone of hybridization between the two species is relatively narrow, only some 150 to 200 miles wide. Hybrids are only very rarely found outside this zone and pure types are often observed, even in the zone’s center. Ornithologists concluded that, although lots of hybrids can be found within the stable hybrid zone, gene flow is restricted across the zone.  Perhaps hybrids are formed only where the appropriate mates are not easily encountered. Furthermore, because of the hybridization, ornithologists have always assumed the two species are closely related. To their surprise, a number of biochemical studies indicate Baltimore and Bullock’s orioles are not each other’s closest relative. Baltimore Orioles are more closely related to Altamira Orioles, while Bullock’s are closest to Streaked-backed Orioles (Rising and Flood 1998).

Pectoral Sandpiper

Like Least Sandpipers, Pectoral Sandpipers have yellowish legs. But Pectorals are much larger shorebirds than Leasts and are not as dark-backed. Identification, however, could be muddled by the large size difference between male and female Pectorals. Males are almost 30% larger than females. The sharp line of demarcation between the dark breast and white belly is is an excellent field mark.

Pectoral Sandpipers breed across the central and western Canadian Arctic tundra all the way into Siberia. They winter in southern South America, the Siberian populations migrating east or across the Great Circle route over the Arctic Ocean to the New World. These later routes result in distances of over 30,000 km, among the longest for any avian migrant. For her dissertation, Erika studied the trematode parasites of Pectoral Sandpipers as these shorebirds made their intercontinental migrations.

Male Pectoral Sandpipers are either polygynous or promiscuous. In any case, males court any female that lands within his territory and males often leave nesting areas before the young hatch. Males associate with females only long enough for courtship and copulation.

Pectoral Sandpipers are relatively common, but numbers are greatly reduced from the late 1800s, when they occurred in “enormous” numbers. Although this shorebird suffered from intense market hunting, habitat loss may also contribute to their decline. Much of the information in this post was gleaned from Holmes and Pitelka (1998).

Least Sandpiper

Least Sandpipers breed across northern North America from Alaska to Nova Scotia. They winter in the southern United States south through central South America. Although they are common migrants across most of the United States, eastern populations may make flights up to 4000 km over the Atlantic Ocean from New England to northern South America (Nebel and Cooper 2008).

This sandpiper is recognized by its small size, dark brown back, and yellowish or (as in this case) greenish legs. Most, if not all, other small New World sandpipers (peeps) have black legs. Observers should beware of much larger shorebirds that also sport yellowish legs, including Wilson’s Phalaropes, Pectoral Sandpipers, and, of course, the yellowlegs. Least Sandpipers foraging in mud may have their leg color hidden. This least Sandpiper was photographed near Aberdeen, South Dakota.

Herring Gull

Erika and I had visions of finding rare gulls during our New Year’s Day drive to Prescott, Wisconsin. But we were able to hallucinate none, finding only Herring Gulls. Rarer gulls such as Thayer’s or Icelands would show little or no black on the underwing tips (see my January 2012 blog). Other species would show darker backs than the gray-backed individuals we observed.

Herring Gulls are perhaps the most common gulls in many parts of North America. Breeding from Alaska to New England, northern Minnesota, and the East Coast, the species winters widely across much of the United States and Central America. In the 1800s, Herring Gulls were almost driven to extinction by plume hunters and egg collectors. Thanks to protective laws, and the Herring Gull’s love of garbage dumps, by the 1960s, numbers fully recovered (Pierotti and Good 1994).

Lesser Scaup

To jump start our 2013 birdlist, on New Year’s Day, Erika and I drove over to Prescott, Wisconsin, on the opposite shore from Dakota Co., Minnesota. We saw nothing unusual, but not for the lack of trying. Perhaps our “best” bird were these ducks, which I presume to be Lesser Scaup. In the first two photos of the same male, you can see that the head is not round, but somewhat crested—usually a fairly reliable field mark for Lesser Scaup. In the first photo, note that only the underwing over the secondary feathers is white. I think a Greater Scaup would have the white extending onto the primary feathers.

In my experience, Lesser Scaup are have duskier sides than Greaters. The third photo is of a female that hung close by the male. In all three photos, the black nail at the tip of the bill is small and relatively inconspicuous. I have previously discussed scaup identification problems in my blog last April. Lesser Scaup winter further north than Greaters, which prefer more open and salt water, and are usually encountered in the winter in coastal habitats (Sibley). Janssen considers the Lesser Scaup to be a winter straggler in Minnesota, but indicates the Lesser is more likely to be encountered in the winter than is the Greater. Unfortunately for my 2013 Minnesota bird list, these ducks swam well within Wisconsin waters.

Common Redpoll and 2012 Banding Report

Common Redpolls have discovered the banding station. We banded six in December and look forward to many more with the new year. Redpolls are an irruptive species whose abundance is tied to seed production by arctic trees like spruce and birch. When these seed crops fail, redpolls invade the northern United States.

During their first and second years, male and female Common Redpolls can not be told apart by plumage. Only after their second year do males become rosy-breasted--see my previous post for a photo of one of these older males.

With the New Year, I have updated my banding summaries for my Dundas and Northfield banding stations. To see this list, click on the appropriate tab at the top of this blog page. Basically 2012 saw similar banding results as in 2011. These results may be a bit deceptive, since, as stalwart readers of this blog are aware, Erika and I travelled during most of last March.