Topics in Field Ornithology

A friend of ours who phones from time to time with news of her birds called this afternoon to tell us that she had a baby vulture walking around in her back yard.  I asked her to describe it and she said it was black with a gray head, but it was mostly white.  I said no way.  She said come over and see for yourself.

By the time we got there, the bird had retreated deep into the taxus hedge at the back of her property.  I waded in carefully and saw the bird in the deep shadows perched on an old abandoned tractor tire.  It was indeed a baby Turkey Vulture and it was indeed mostly white.

This bird should clearly still have been in the nest.  It was covered with white down, what banders call the “local” plumage since it never gets very far from the nest.   The black wing feathers are molting in, but the tail feathers are only just emerging from their sheaths.  However, the head and beak definitely belong to a vulture.

Fledgling Turkey Vulture

Fledgling Turkey Vulture

Our friend’s place has an abandoned barn that we knew was a vulture roost.  They fly in and out of the hayloft window and can frequently be seen perched on the windowsill and on the roof peak of the barn.  I checked out this barn a year ago for the Ohio Breeding Bird Atlas program.   I found half a dozen active Barn Swallow nests in the lower story and three vultures roosting in the hayloft, but no sign of a nest.  I guess I should have kept checking.

Our theory is that the baby bird took the big leap a bit too soon, as baby birds sometimes do and now finds itself unable to reverse the process.  I suspect that the parents are aware of the situation and are just waiting for the humans to clear off so they can attend to the baby.  I advised our friend to call the raptor center at Glen Helen, near Yellow Springs for advice.  They said to put the baby back in the barn.  A plan is in hand to do just that.  The lady at the raptor center said they have several instances of straying Turkey Vulture chicks each summer and putting them back seems to work best.

This was the high point of the day, but we had already had an exciting morning watching the young Ospreys at the Mound Road access point at Caesar Creek Lake.  We had good views of all three of the young birds perched close by and in the air.  The birds were judged to be juveniles by the white tips on the back feathers, scapulars and wing coverts.  We were even able to see the orange irises of two of the birds.  These will turn yellow later in the year.  There was no sign of the adults; they may be on their way to Venezuela already.  The young will probably hang around the nest site for another month or so until they realize they are on their own.  Then they, too, will head south, following a routh that they were born with.

Juvenile Osprey. Caesar Creek State Park, Ohio

Juvenile Osprey. Caesar Creek State Park, Ohio

One of the most difficult parts of communicating the location of a good bird (or a good birding spot) is uncertainty about how much knowledge is shared between the parties. Between some interlocuters “the cedar tree by the side of the road where the long-eared owl was last year” is good enough. Others require turn-by-turn directions from their home 300 miles away. A couple of years ago, I thought GPS was the answer. I would specify the coordinates and GPS-equipped birders would be able to navigate there directly. Unfortunately, the technology has progressed so rapidly that lats and longs have been completely bypassed. Maybe OnStar can get you to a set of coordinates, but most car GPS receivers are all visual; they don’t have any means of entering target coordinates. The obvious answer is some kind of map, but most of the online mapping services suffer from the same shortcoming.

But now there is My Maps from Google. My Maps lets you annotate and save a map from Google Local and send a link to it to all your friends. The map has all of the interactive functionality of the basic Google Local. I can use it to indicate a spot in a local wildlife area, and when you click on it, you can zoom out, click on your house, get directions and all the things you normally expect. This same map is just as useful to a birder in Cincinnati as it is to one in Cleveland. And best of all, it is dead simple, all drag and drop, and no programming. It only takes about ten minutes to achieve a reasonable level of skill. I wish all software were like that.

To get started, point your browser to Google Local . You should get a display that looks something like this:


This one is centered on my house just north of Wilmington, Ohio. Yours is probably centered on someplace in your neck of the woods.

02my-maps.gifLook at the tabs on the left. Click on “My Maps” as below. For now, resist the temptation to click on “Create new map.” First you want to zero in on the target area for your map, because that is the first thing your reader will see. We will use the pan and zoom controls indicated by the red arrows below to move the focus to Cowan Lake State Park, one of my favorite local birding spots. First, I will zoom out to get some perspective, as in the figure at right below.


Look in the bottom left hand corner. There is Cowan Lake. Now we need to center it and zoom in to make it a pretty picture. We do this with the cross-shaped controls on the left. There is also an undocumented method that is very handy for this sort of thing. Place the cursor on the lake and double click. Google centers on that point and zooms in by one increment. In any case, a couple of clicks should get us a map like the one below. Now, click on “Create new map.”


The cursor is in the title box on the left. You can enter a title and a short description of the map and what it is supposed to do. This gives us the basic map, we can begin to annotate it. Just to the right of the pan and zoom controls, you will see four icons that weren’t there before. The first (leftmost) of these is a little hand. This control essentially duplicates the pan control. You can use it to grab the map and move it. Just click on the hand, then click and drag the map. The next three are the three basic means of annotating the map. The little balloon annotates a point; the jagged line allows you to draw consecutive line segments on the map; and the last gives you way of drawing a colored polygon on the map. Let’s annotate a few points since that is the control you will probably be using most.

One of my favorite birding spots at Cowan Lake is the east boat ramp on the south shore. To annotate this spot, click on the balloon icon and drag it over to the desired spot as below.



09annotation.gif When you let go of the mouse button, an annotation panel appears. Click in the title box and enter an appropriate title. Then click in (or tab into) the description box and write as much description as you think your readers might find useful. When you are done, click OK. The annotation panel goes away, but the icon, the title and the first line or two of the text appear in the panel to the left of the map. Clicking on the title brings back the annotation. If we continue in this way, dragging and dropping the balloons on various points, we build up an map rich in information. Not only that, but the map retains all the functionality of the basic Google Maps utility. I can zoom out to Sacramento and get turn-by-turn directions to the east boat ramp. This flexibility is the great power of My Maps.


But wait, there’s more. Lurking under the annotation panel are a whole slew of additional symbols that give interesting possibilities. Look at the figure at right. I have put a marker on the Lotus Cove Trail Head, but that is not a birding spot. It is just a place to park. I can distinguish that by changing the icon to something more suitable.

I do this in the following way. In the panel to the left of the map, I click on Lotus Cove Trail Head. This brings up the annotation I created earlier. Click on “Edit.” This recovers the annotation dialog, from which I can make whatever changes I wish. Now I click on the balloon icon in the upper right corner. When I do that, a new panel appears that gives me the choice of about a hundred new symbols. I scroll down and choose the capital “P” for parking and the change is made


The map below shows what you can do with this. I have added a tent to indicate where the campground is, and a little sailboat to show the location of the marina, and an exclamation point to warn that an indicated road is actually private. Finally, Google Maps isn’t too good about including internal roads in the park, so I have used the line drawing tool to draw in the roads down to the beach and to the Big Hill picnic grounds. These are two of the best areas in the park and deserve the extra attention.


Finally, we need a way to make this map available to others. Google gives each map a URL so it is accessible to anyone who has the address. You can bring this address up by clicking on “Link to this page” in the upper right corner of the map.


When you do this, the URL appears in the address box of your browser. From here you can copy it and paste it into an e-mail or make it a link on a web page, like this one. I have done that with the finished map, which you can see by clicking here.

A couple of final words. First, making these maps is a web application and as with most web applications, it is excruciatingly slow if you are on a dial-up connection. Even with a broadband connection, it is not nearly as fast as a dedicated application that runs directly on your computer, like your word processor. Success requires a little patience.  The spplication is also a bit balky sometimes. I figure it is because every mouse click must be sent out over the web and a response must be sent back and some of them just go astray. One important corollary of this is that you must save your work early and often, as we used to do in the olden days. Google tries to save after every change, but sometimes the magic just doesn’t work. You have to take responsibility for it yourself.

of the biggest challenges of my first year of birdwatching almost fifty years ago was separating young Forster’s Terns from young Common Terns. And so it remains today. I find myself going back to the books every time I encounter one or the other. I had another opportunity to do just that yesterday (9 Oct 06) when I encountered 25 juvenile/first winter Forster’s Terns on the beach at Caesar Creek State Park. (Directions)

I can state without equivocation that these birds were Forster’s and not Common because they were quite vocal and the two species are easily distinguished by call. But looking at birds I knew to be Forster’s Terns, I nevertheless experienced some confusion about several ID points. So I whipped out my trusty Panasonic Lumix DMC-FZ50 and fired off about 200 pictures. Here are the most instructive. Click on the picture or on the link for a bigger view.

As far I was could see all 25 of the observed birds fell between the two extremes shown above. The bird in the foreground is still substantially in juvenal plumage. Truly juvenal birds would show a gingery fringe to most of the mantel feathers, scapulars and wing coverts and a dark brown cap. The fringes are all gone now and most of the back shows newly molted gray feathers. The tertials are very dark and there are still some dark-centered median coverts. The head is in the process of losing the dark feathers of forehead, crown and nape. The structure of “mask” is already evident.

The bird in the background looks very much like a basic plumaged adult, but the nape of the neck usually retains some of the darker feathers of the juvenal plumage. (The nape of the basic plumaged adult is pretty much pure white.) The flight pattern shows differences, as well, as shown in some of the pictures below.

This collection of birds shows the range of head markings present at this date. The bird numbered “1” still shows substantially the head markings of the juvenal plumage, whereas, bird “2” shows an almost completely white forehead, crown and nape, give the masked pattern which many birders use as a diagnostic indication of Forster’s Tern. The partial hood of the birds in the earlier molt stage could easily lead to confusion with basic plumaged Common Tern.

Common Terns reliably show a carpal bar in all plumages except alternate. The photos above show that in juvenile/first winter plumage the Forster’s Tern shows some dark scapulars that might be mistaken for a carpal bar. The carpal bar of the Common Tern is due to dark coverts in the patagial area and has a different look.

First winter Forster’s Terns in flight. The light-colored primaries are similar to those of the adults, but it must be noted that the wings of the first winter Common Tern lack the dark wedges that characterize the adults. This nullifies one of the best ways of separating adult Forster’s and Common Terns. However, the first year Forster’s lacks the dark carpal bar and the dark gray secondaries of the Common Tern

The tail is also subtly different. Note the dark markings on the inner webs of the outer two or three rectices. The detail here shows this a little more clearly. Common Tern shows a dark outer web on the outer tail feathers only. This is a significant difference, but one that is hard to spot in the field.

I lived in Britain for three years in the late 70s when jizz birding was rapidly gaining adherents. In most cases, I thought (and still think, to a large extent) that invoking jizz was a indication that the observer was either too inarticulate or too lazy to say what he or she really meant. It was sort of like distinguishing the yellowlegs by saying that the greater has “a bigger beak.” Bigger than what? In the absence of a lesser yellowlegs to compare it with, the observation lacks persuasiveness. On the other hand, observing that “the bill was slightly longer than the head and slightly upturned” is much more useful statement, and one that few of us would argue with.

On a deeper level, “jizz” is a function of the basic human pattern recognition ability. A great deal of the human brain is highly specialized for this function. We are incomparably better than computers at recognizing patterns. And the more often we encounter the pattern, the better we get at recognizing it. For instance, if I see Bill Whan across the room at a meeting, I recognize him immediately, even if he is dressed differently, turned in a different direction, sitting or standing, wearing a hat or not, etc. I suppose you could say I identify him by his jizz. If I can do it with Bill Whan, is it not equally acceptable to identify birds the same way?

The short answer is “yes.” The long answer is that it depends on how well your pattern recognizer is trained. We can all identify robins in a wide variety of circumstances because our pattern recognizer has such an abundance of experience with robins. If we turn to dowitchers, however, the situation is much different. I have been struggling with dowitchers for 40 years. Last year at the shorebird symposium, someone told me about the “swallowed a grapefruit” tip. The next day at Cedar Point, we found a nice stretch of shallow water that held a bunch of really instructive birds. In particular, there were several small groups of dowitchers of both species, and the “swallowed a grapefruit” effect was very evident; distinctive, even.

However, back home, where we experience dowitchers in onesies and twosies (if at all), the “swallowed a grapefruit” effect is not nearly as easy to use, owing to the lack of comparison. Now, if I were in a situation where I encountered both species of dowitchers daily, I would probably become much more confident in using that comparatively elusive element of the dowitcher morphology.

In my experience, pattern recognition skill often has a fairly short shelf life. I have been to Hawk Mountain several times. Each time, I come away able to distinguish Cooper’s and sharp-shinned hawks at a range of two miles. However, after a fairly short time back home, I find myself as puzzled by accipiters as I ever was. The confidence I had developed in a day of intensive pattern recognition training has faded with time.

And that is what makes my wary of endorsing “birding by impression.” The variation of pattern recognition skills across observers and through time means the assertion of an identification on the basis of an “impression” must be viewed with a certain degree of skepticism unless the observer has a widely accepted reputation for accuracy in such circumstances. For the rest of us, we should be prepared to present a bunch of corroborating details.