Separating Louisiana and Northern Waterthrushes

Well, we had planned to start with gulls, had made several announcements and then kept the world waiting (in case the world had noticed) but now finally we have a lift-off: the first post in what will surely become a series of blog cooperation projects between Charlie Moores and yours truly, Belltower Birder. Within this cooperation we plan to combine whatever our respective strengths are to see if we can't come up with a good piece of bird blogging that each of us would not have been able to achieve himself. This time, it is the identification of the two waterthrushes and we hope it will prove helpful during this - and the next few - migration periods.
You can find the very same post on Charlie's blog here, by the way, as that's how the cooperation works.

It's spring, migrants are everywhere, and you catch a glimpse of what looks like a small warbler walking in a damp, shaded area. As you move closer you get better views- it's a brownish bird, streaked below, possibly a waterthrush, but - crucially - it's not calling. Your prize may fly off at any moment, so just what features do you need to concentrate on to make a positive ID...?

The two species of Waterthrush, Louisiana Waterthrush Seiurus motacilla and Northern Waterthrush Seiurus noveboracensis, are very similar to each other but are themselves easily distinguished from other species within the North American wood warblers. They basically form their own genus Seiurus, with the only other member being the strikingly different Ovenbird Seiurus aurocapilla. The Ovenbird though is so different from the two waterthrush species (in multiple aspects) that many authorities consider a review necessary that would then place the waterthrushes in a genus of their own. All three species, Ovenbird, Louisiana and Northern Waterthrush, share the following field characters that can be used to separate them from other North American wood warblers:

• They are brown above and pale (buffy or white) below with bold brown streaks.
• They are largely ground-dwelling and only seldom seen on branches.

The Ovenbird is easily distinguished from the waterthrushes by its lack of a pale supercilium (the “eyebrow”), its whitish ring around the eye, warm reddish-brown crown and - frankly - by its completely different appearance.


Ovenbird Seiurus aurocapilla

So basically, unless a vagrant Redwing Turdus iliacus from Eurasia is taken into account, a ground-dwelling small song bird that is brown above, pale below with brown stripes and shows a pale supercilium is bound to be a waterthrush.

So far so good, but unfortunately (or fortunately, depending on how much you enjoy a good challenge) this is where easy ends and not-so-easy begins: the identification and separation of the two species of waterthrush... When confronted with a waterthrush, these are the field characters which we have found can be used to distinguish one from the other (field-guides do mention other characters ie Louisiana's buffy supralorals and buffy rear-flanks but in our experience these are difficult to see under normal viewing conditions):

The movement of the tail and rear body
Both species constantly bob their tail and rear body, but there is a slight yet distinct difference between the two.
Northern Waterthrush: a plain up-and-down bobbing of the tail and rear body.
Louisiana Waterthrush: a more "sinewy" bobbing that includes also moving the tail/rear body to the sides.

The shape and colour of the eyebrow
Northern Waterthrush: narrowing at the rear and very often yellowish or buffy white.
Louisiana Waterthrush: broad, bold and white, and not narrowing.

The shape and length of the bill
Northern Waterthrush: rather short and thin, the lower mandible being thin and straight as well.
Louisiana Waterthrush: long and strong, the lower mandible often appears strong and bent upwards, (very remotely similar to a Yellow-billed Loon Gavia adamsii!).

This Northern Waterthrush shows the typical, rather thin supercilium and a long and thin bill.

The supercilium is more bold and bright on Louisiana and the bill appears a bit longer and especially stronger than on Northern

Patterning of the chin/throat
Northern Waterthrush: most birds have a finely striped chin, but some can show a white chin comparable to Louisiana.
Louisiana Waterthrush: always without fine stripes, pure white.

A striped chin therefore is diagnostic for Northern Waterthrush, but an unstriped chin cannot be used to definitely identify a bird as Louisiana Waterthrush!

The chin of most Northern Waterthrushes shows very fine streaks

Louisiana Waterthrushes always show a plain white chin without streaks

Colour of the breast and belly
Northern Waterthrush: varies between whitish and yellowish, but never shows a contrast between the tone of the breast and the flanks.
Louisiana Waterthrush: always whitish with buffy rear flanks.

Pattern of stripes below
Northern Waterthrush: often relatively dense, usually more heavily striped than Louisiana.
Louisiana Waterthrush: often relatively few.

An additional difference that we came to notice but still needs to be tested in the field is the patterning of the stripes on the rear flanks: Louisiana Waterthrushes tend to show two parallel and straight lines along the rear flanks, very nicely patterned as the small individual stripes are completely in line. In Northern Waterthrushes, these lines on the rear flanks still show the individual stripes but they are not parallel but in a pattern reminiscent of a spruce twig, pointing in different directions. There is a considerable amount of individual variation however and this field character will not work on all birds.

A Northern Waterthrush showing the "spruce twig pattern on the rear flanks

A Louisiana Waterthrush showing two nice parallel lines on the rear flanks

Leg colouration
Northern Waterthrush: dull, darker pink.
Louisiana Waterthrush: bright pink, almost reddish.

The typically dark, dull pink legs of a Northern Waterthrush are often difficult to see against the usually dark and muddy background of its preferred habitat

The legs of a Louisiana Waterthrush are usually very bright pink and in strong contrast to the same dark background

In general, the Northern Waterthrush appears more as a "dull and dirty" bird, with its darker legs, tainted supercilium and often yellowish tinge below. The Louisiana Waterthrush in contrast always gives the impression of a neat, clean and stylish bird, based on its clean white supercilium, bright legs and white colouration of the breast and belly. This difference might not work in all birds, but describes the general appearance quite well as can be seen on the two images below.

A typical "dull and dirty" Northern Waterthrush

A typical "nice, neat and clean" Louisiana Waterthrush

All these field characters are well established and should allow the identification of (almost) all the waterthrushes one encounters. However, most of these field marks are of a relative character and therefore require a certain amount of experience with at least one of the species, most likely to be the more common Northern Waterthrush. How else is one to determine if the bill of a bird is long or longer, if the stripes on the breast and belly of a bird are numerous or less numerous and if a whitish supercilium is bright or obviously bright? Furthermore, some of the field marks mentioned above are subject to individual or geographical variation and not entirely foolproof as rarely single individuals of one species will show a character more typical of the other species.

We would therefore like to introduce here one more field character that might be useful in identifying all individuals, regardless of geographic origin or individual variation as the field mark we present here was shown in other species to be rather stable and reliable. However, this field character cannot be regarded as established because we have only been able to test it on a limited amount of individuals in the field and on photographs of both species we were able to study.

From these limited examinations it appears that the Louisiana Waterthrush shows a primary projection that is significantly longer than that of the Northern Waterthrush. Primary projection is the extent to which the primaries project beyond the tertials on the folded wing of a bird.

The primary projection can be measured by comparing the primary projection with the length of the visible tertials and estimating the relative difference in %, as shown in the following image. (This may sound complicated but it’s actually a rather easy process once you become familiar with which feathers are tertials and which are primaries.)

The primary projection [A] of the Northern Waterthrush depicted above is roughly 50-75% the length of the visible tertials [B] whereas it is closer to 100% in the Louisiana Waterthrush seen below.

Summary
The identification of both species of waterthrush appears quite difficult at first but is a rather straight-forward affair in most birds once the following key features are checked:

• the movement of the tail and rear body (up-and-down only, or up-and-down and also sideways)
• the patterning of the chin (white or with stripes)
• the supercilium (small and often yellowish or bold and white)
• the colouration of breast and belly (yellowish/buffy or pure white)
• the leg colouration (dull or bright pink)
• the structure of the bill (slender or strong)

Due to individual and geographic variation, not all birds show the field characters normally typical for the species and the identification should thus always rest on as many of the field marks mentioned above as possible.

Based on our limited experience with both species, we present one further field character that might be less prone to vary and might facilitate the identification of even the more tricky individuals:

• the primary projection (length of the primaries projecting beyond the tertials on the folded wing) of the Louisiana Waterthrush is close to 100% of the visible length of the tertials whereas this value is closer to 50-75% in Northern Waterthrushes.

We hope this apparently new but still largely unconfirmed field character inspires birdwatchers in North America to specifically take a deeper interest in the identification of the two species and test our suggestion in the field. We welcome any feed back and opinion on the subject.

Jochen Roeder and Charlie Moores, May 2007

Text by Jochen Roeder (www.belltowerbirding.blogspot.com), photos by Charlie Moores (www.charliesbirdblog.com).
Photographs taken in Central Park, New York, April 2007, except Ovenbird taken at Garrett Mountain, NY May 2006

How to avoid selling your soul for a Bird Species

During Laurent's and my trip to Crane Creek on May 1st (see full report here), something very remarkable happened. So remarkable indeed that it completely changed my way of seeing the world, like turning from looking at something to seeing something, which is quite different.

Let me start where one always aught to... No, not at the Bar, at the beginning:

We all have our Nemesis bird, the one that always gets away because it is so busy showing itself to all the other birdwatchers in the world, and in my case, this is Owls (and rails, too).

I had however discovered a very effective strategy of getting a few owl sightings here in Michigan which was to
a) chase an Owl others have found and posted on the Internet
b) take Laurent with me.

This had led to nice observations of Snowy and Barred Owls but I somehow felt I should at least try and find one species all by myself to see if the curse of the Nemesis bird was still upon me or had finally been lifted. This one special owl species - I had decided - was going to be the Eastern Screech Owl.

There are some questions that would take a whole life of contemplating to answer and some questions we take to our graves, still unanswered, like this one:

Who did I think I was fooling?

Of course I soon realized there was no way I was ever going to find an owl species by myself.
Never.
But there was one question to which I finally found the answer:
Why was I not finding an Eastern Screech Owl?

In the deep and moulding vaults of the secret society called the "Owluminati" I discovered and studied a rare volume about the Eastern Screech Owl and the rituals necessary to conjure a sighting: To view an Eastern Screech Owl, a desperate Birdwatcher was to present the heart of a dearly loved one on the stairs of the Great Pyramid of Tenochtitlan to Quetzalcoatl.

I do like owls. And I do enjoy a sacrifice or two to see a bird. But really, and even though this might disappoint many of my fellow birdwatchers, I was not willing to follow this ritual but had opted for a life without an Eastern Screech Owl instead.

Then came May 1st, and our trip to Crane Creek.
Well, Laurent was with me, so I should have guessed something like this was going to happen, but it was still a complete surprise.

We had birded the whole board walk and were in a bit of a hurry to get to Metzger's Marsh nearby for some shorebirds and waders. While passing two birders, I mentioned that there had been a Northern Waterthrush earlier at this very spot and they thanked us by pointing out that there was a Whip-poor-will perched close to the board walk a bit further on.
That's what I like about birders: knowing when it is time to shut up and enjoy a bird and when to chat and gossip with fellow birders.
So when we reached the next group of birders, we inquired about the Whip-poor-will.
A very friendly lady first tried to explain to us where it was but soon realized that a perched Whip-poor-will was unlikely to be found following a description, so she actually went back a few metres with us and pointed it out.
Now, don't ask me how I managed to mess up the focus on a perched bird, but here is the scene and the bird:




After we had marvelled a good few minutes, the very same lady casually mentioned, and this is a citation of her very words: "And while I am at it: anyone wants to see the Eastern Screech Owl?"

Needless to say, my answer was something along the lines of: "Well, yes, frankly, and if it is not causing you inconveniences, I might find myself inclined to welcome your help in receiving a glimpse of that very species you have just mentioned by closely following your guidance, but please let me assure you that this favour of yours shall only be asked for in case your time schedule will allow further delaying of your other certainly far more important issues."

It could also have been more like "What ... yes ... where ... please?!?", I can't quite remember.

And this is what we were shown a few metres further down the boardwalk, a tree right besides the path that we had walked by two times:

An Eastern Sigh Owl

So this was the trick: have someone else sacrifice the life of a loved one to see an Eastern Screech Owl and then just memorize the location where they found it, pass the information on to others and so on.
I am very grateful to the lady for showing us the bird but am not so sure what to think of the guy who first found the owl... Would I want to go owling with him at night alone?
Well whatever, one thing's for sure:

Life's great when you're a birder!

"I and the Bird" No. 48

A long, long time ago, in a galaxy not too far away but so long ago that it was in my youth, picking a shampoo at a super market was easy. Of course it was easy because I was far too young to go to a super market myself and it was my mom who'd buy the shampoo, but it was mostly easy because there was only a limited variety.
Standing in front of a shampoo shelf was a rather straight forward thing, you quickly scanned through the two to three different brands and just had to decide if your hair was more on the dry side or less on the dry side of the scale. On you went as a decent mom to the candy section to get your son whatever he asked for (I wished).

Nowadays, with globalization and all that fancy stuff, getting a shampoo is nothing short of a nightmare. First of all, finding your shampoo section can be a real problem because it is rather easy to mistake the conditioner or body wash section for the shampoo shelf. And when you've asked a few people for directions, got guided (in tears) through the maze that used to be a super market and are standing in front of the shampoos, you're not really closer to your aim of obtaining the right one. The masses of different products are just unbelievable. And as if having to choose from / cope with all these different brands wasn't already hard enough, you now have to decide or - gasp - know what hair type you are, and the classification system of hair types nowadays is more complex than that of South American hummingbirds!
Complete, overwhelming chaos.

And this, my dear and inclined reader, is what bird blogging and buying a shampoo have in common: an overwhelming and -honestly- unmanageable supply of possibilities. How can you be sure you're reading the right bird blogs (easy: link to Belltower Birding), how can you know you're not missing out on posts everybody else is reading and talking about, how can you stay up-to-date with your bird blogging?

You say it's difficult?
Think it is impossible??

Ha !!

Not anymore, thanks to "I and the Bird", the bird blogging institution that facilitates life and brings you and your bird blogging up to scratch.

The latest edition of "I and the Bird" is hosted by Greg Laden on his incomparable blog here and is the ultimate "Field Guide to the Bird Posts".

This is what others have to say about Greg's Field Guide:

"A new classic." - Scientific American
"A treasure of valuable information." - Time
"Superb ... Unequaled." - The New York Times
"Undoubtedly the finest guide to Global Bird Posts." - Birding

Well, maybe these are the comments Sibley received for his field guide, but Greg's Field Guide, as the natural supplement to Sibley's Work, can certainly be included in these reviews.

A new classic is born!

My Camera and I : Becoming Friends - Good Friends

On May 1st, Laurent took me and my new camera to Crane Creek, one of the migration hot spots of the Great Lakes region and frankly the whole of North America. We only had a few hours there but a few hours at Crane Creek are always better than a few hours not at Crane Creek (so I was told), especially when it is your first visit to the area.
After my camera and I had started to get to know each other a little bit at the Arb, this was meant to be the first real test of the strength of our newly established relationship, so I was almost as anxious to see how my camera would behave as to see how the birds would perform.

What can I say?
Only the best as my camera proved to be very well behaved in public and the company of birds and the birds themselves were performing very well as well.
This, therefore, is the first post on Belltower Birding that will not be so much about the words than about the pictures, a little celebration of my new camera, the beauty of birds and the wonder of spring migration around the Great Lakes.

Hope you enjoy it...

The board walk at Crane Creek where all the song bird action takes place

Capturing a Snowy Egret in flight proved still a little difficult ...

...but this Great Blue Heron managed to calm down my slightly disappointed camera, ...

...and this Great White Egret finally fully restored the camera's self esteem.

This female Bald Eagle had challenged the camera by hiding amongst thick branches and twigs but had no chance of escaping, no chance at all.

Thrushes were still dominated by Hermit Thrushes, which I didn't mind too much ....

...as they proved to be exceedingly cooperative.


A Wood Thrush was a bit elusive but still a marvellous sight ...

...and American Robins are nice as well.

A Common Grackle posed as a multi-task - or rather multi-straw - builder...

...while a snobby male Rose-breasted Grosbeak apparently couldn't be bothered to attend the photo shoot

A newly described Wintergolden-Summerruby-Crowned Kinglet in its summer plumage

We encountered a total of 10 wood warbler species, Palm Warbler, Pine Warbler, Common Yellowthroat, Northern Waterthrush, Nashville Warbler, Yellow Warbler, Yellow-rumped Warbler, Black-and-White Warbler, Cape May Warbler (nice!) and Black-throated Green Warler (this time I got the spelling of the colour right).
The warblers sure were difficult and the following images don't do their beauty justice, but I think my camera braved this extreme quite well and we learn from our mistakes (like not using the flash when photographing a warbler against the background of a bright blue sky, which from now on I shall do).

Mr. Handsome himself: the Yellow-rumped Warbler

Same bird, different angle, still looking good

Western Palm Warbler, slightly out of focus but I don't care.

Black-throated Green Warbler

A frustrated Cape May Warbler:"Use your flash, stupid!"

Nice of him to still pose for the camera

Black-and-white Warbler, head-on view

Black-and-white Warbler upside down, making it the first documented White-and-black Warbler ever

And from behind, the first documented Relbraw etihw-dna-kcalb for Crane Creek

Apart from being a good bird watching day, the afternoon at Crane Creek was also excellent regarding Birdering, as we managed a fine encounter with Kenn Kaufman. Well, we didn't get in direct contact and I only managed a photo documentation (not a great shot) of this very special birder record, but as you won't believe me without proof, here's the pic:

R E V O L U T I O N

When I travelled through southern Ontario and Michigan in May 2005, I had my trusty old camera equipment from the 1980s with me, the monstrous and scary yet somehow pretty good Novoflex lens and an old Minolta Camera, like this one. As you can see, it did not have a winder and you had to transport the film yourself after every shot. I got pretty quick at this over the years, but that speed apparently worked hard on the camera's mechanics as I usually was only able to use them for two to three years until the film transportation system would collapse and I was forced to get a new camera.
And this is what happened during my trip through North America in May 2005, after I had found a Porcupine during a hike around Trout Lake. Here's the last picture I was able to take, and then the curtain fell completely, literally.


Back in Germany I enquired about a new X 700 but was told these were not being produced anymore and I'd have to get one second hand, best through eBay or other Internet sources.
Well, sure I could have organized myself another antique camera, after all they really weren't bad, but I decided this was a sign, a little hint by fate to push me towards digital photography.
Problem was: finances were not overly abundant after a trip to another continent and so it took me a long, long time - the longest time ever without a camera since I was 11 years old - until I received a new and - yes - digital SLR at the end of last week.
It's nothing overly fancy of course and once I have tested it enough to know what I am talking about I might write a review on this blog, but I am sure it will serve well to put more colour onto this humble blog and more belief in my future claims of Bachman's Warblers and Labrador Ducks along the Huron River.


Frankly, I had not realized just how massively outdated my equipment and thus myself had been back until 2005 and when I went to the Arb on Sunday with my wife to test the new camera (my wife also got herself a really cool point-and-shoot), I had the distinct feeling of having switched from this to this without having first obtained my PhD in Astrophysics and the latter being a big mistake.

Oh dear, how was I going to cope?

Well, I need a lot of practice, particularly preventing camera shake from not holding still enough (the Novoflex was much more heavy which meant there was little risk of your pulse messing up your image as in this light-weight equipment), but considering I had pictures like this on my blog before ...



it seems I am doing much better with this now:



This (above) was actually the first ever bird picture with the new camera, and even though the Cardinal is not sitting in a bush with snow, it is still a worthy reintroduction of the photographing Belltowerbirder to the wild.
Northern Cardinals are actually such nice and obeying photo objects that I managed a few more shots. I know these pictures are not so special, but hey, this is my new camera and these are actually pictures I took myself, not just links to other pages, so you'll have to live with it for a while! Therefore, here are the Northern Cardinals:




We spent a total of 3 hours at the Arb around noon and it was yet again rather busy - weekend - but less crowded than before with most students gone (summer break). Bird life was not so abundant due to the time of day and people around, and I was focusing with and on my camera anyway and not fully paying attention to every peep from the canopy and rustling of leaves from the forest floor (it is very difficult to handle an auto focus for the very first time in your life, I can assure you that in case you have forgotten).
Photo opportunities came in the form of the Superior Raptork (formerly called Turkey Vulture) at the beach section, and I tried to make the most of my chance and obtain a decent image.



Of course, Belltower Birding always thrives to deliver insights beyond the cool and one of the advantages of a 10 Mega pixel camera is that you can zoom in quite nicely. What follows is heavily cropped, but it allows us to age the bird. The facial skin is still clearly blackish and not fully and bright red as it should be for an adult, and the bill is still dark instead of Ivory (oh, the word) as in decent adults, so there we have it aged: a bird in its second calendar year, which will soon be celebrating its first birthday.



I have now been in Ann Arbor more than half a year and my new camera now finally allowed me to thank the city and South-East Michigan in general for the Barred and Snowy Owl, for the Black-throated Gray Warbler, the Red-shouldered Hawks, Lesser Scaups and all those other lifers and goodies. Thank you all, you're great and GO BLUE !!!




And last but not least for the first day out with a brand new camera, the warbler pics I got.

This is where the auto focus of my camera realized how unfortunate it was to have ended in the hands of a bird photographer. The camera struggled and it worked and it cursed and it wished an old nanny would have bought it to take pictures of her little doggies but no, it had to be warblers in a sea of twigs and leaves. Here are the least shameful results. I suppose I still need to make a few changes on the technical settings of the camera, but I'll work it out before the arrival of the Swainson's Warblers at the Arb, for sure. I had temporarily wondered if it was possible to publish these as proof for Ivory-billed Woodpeckers in Michigan and buy myself a nice little house in Costa Rica from the funding I'd receive, like Rancho Naturalista. But I guess I am just an honest guy, so here are some pictures of Yellow-rumped Warblers from the Arb last Sunday...


So let's go then, bring on spring migration !