Tuesday, April 30, 2013

Local migration

The spring passerine migration is moving at a snail's pace here in Connecticut. As a co-worker of mine likes to say, "Aaaaand we're off like a herd of turtles!" As it should be in April in New England!

We've had a refreshingly cool spring with many nights of unfavorable migration conditions. So, for once, arrival dates are "normal" or perhaps even a bit behind in some cases. After last spring's record temps and insanely early foliage and birds (with foliage coming well before the birds), I am especially pleased by this year's developments. I know better than to think that this is an indication that climate change isn't occurring at a drastic pace, but it does make me rest a bit easier to see things much closer to normal as compared to this time last year, if only for a little while.

The most tangible silver lining here is that we're actually able to see warblers right now. Barring a prolonged major warmup, we won't have to fight through fully leafed-out trees for views of neotropical migrants when the first big waves arrive.

So when will that first wave hit? That all depends on, you guessed it...the weather. We are currently enjoying beautiful weather with many days of clear, sunny skies in the forecast. But the migrant flocks are few. Why?

Well, here in southern New England, we've experienced a slight easterly component to the winds over the past couple days. And a quick glance at the extended forecast currently predicts that easterly element to continue over much of the next ten days. Of course, this is subject to change at any moment. But when this happens, just a slight easterly component to the wind is usually enough to divert the bulk of migrants to our west. The birds keep migrating, but fewer end up in CT during these conditions. Breeding birds will continue to return, and migrants will still trickle through, but the migrants will be less numerous on east winds during May.

[*Note: This applies locally and to most east coastal locations. This is an over-simplification, as there are examples during which east winds can result in coastal fallouts of southern species (i.e. if they're ahead of an advancing low pressure system that pushes them offshore in the south but blows them back onshore further north), but those are special situations.]

So if the current forecast holds, we could be in store for a rather lackluster migration over the next week or longer in Connecticut. However, if you live a bit inland to our west, you should have no problem whatsoever. Enjoy our birds!

 - NB

Friday, April 19, 2013

Glaucous x Glaucous-winged Gull hybrids

I know it's mid-April but I wanted to get one last winter gull post up before I turn my attention to more recent happenings. Here are photos of two presumed hybrid GLAUCOUS x GLAUCOUS-WINGED GULLS at La Push, WA on Jan 28, 2013. These birds were part of a killer concentration of large gulls enjoyed by Frank Gallo, Ryan Merrill and myself for several hours on this morning. I'm not sure I've had this much fun standing in pouring rain for so long! We had 8 species plus 3 hybrid combinations. I'll say it again: the next gull ID conference must be held here. If nearby Aberdeen, WA native Kurt Cobain was into gull identification he would still be alive today...although we wouldn't have had the same great 90's grunge to listen to, so maybe things turned out for the best after all...

Then again, perhaps hours of head-scratching while staring at soaking wet hybrid gulls would have resulted in the same sort of depression, angst and drug addiction that produced albums like "Nevermind" or "In Utero."

But onto the birds!  First up is a first cycle individual that looks much like a GWGU in plumage and structure at first glance, but with a few glaring differences. Most obvious are the contrasty pale primaries. Also note the rather parallel-sided bill with strong hint of a GLGU-like two-toned pattern. The ground color of the bird is fine for Glaucous-winged, but note the well-patterned wing coverts, which might also be explained by GLGU genes (most presumed pure first cycle GWGUs seen on this trip were much less patterned above). In flight, again the pale primaries and speckled upperparts stand out. The tail pattern is also a bit more patterned and pale-based than you'd expect on a pure Glaucous-winged.




presumed first cycle hybrid GlaucousXGlaucous-winged Gull

Our other hybrid is in its second or third cycle. This bird appeared more Glaucous-like in size and structure but clearly holds genes of a darker-winged species as well. Note the patterened wingtip, dark tail, darker upperparts - all telling us that this is no pure Glaucous Gull. This bird was huge, perhaps the largest individual among the couple hundred gulls lined up along the wall that day.

As for the darker-winged parent, here is why we went with Glaucous-winged Gull over other likely combinations such as American Herring Gull:

 - Dusky iris. At this age, the iris color is intermediate between GLGUxGWGU. If American Herring Gull was the other parent, we would expect a very pale staring iris color by now.
 - Upperpart color. A bit paler than the nearby GWGUs, as you'd expect in a hybrid with GLGU. If we were talking GlaucousXHerring, we'd expect a significantly paler mantle color than Glaucous-winged. Perhaps the only benefit of the dreadful weather on this day was our ability to judge shades of gray thanks to a complete lack of sun glare.
 - Very faint wingtip pattern, paler than is typical on presumed F1 hybrids of GlaucousXAmerican Herring. However this could be explained by a backcross with more Glaucous than American Herring Gull in it (in which case we would really expect a paler mantle shade).








presumed 2nd/3rd cycle hybrid GlaucousXGlaucous-winged Gull

Could these features be explained by a Glaucous Gull with some Vega Gull genes in it? Possibly, so perhaps that shouldn't be dismissed. However most photos of presumed GlaucousXVega hybrids that I've seen show birds that look very much like GlaucousXAmerican Herring Gulls. When it comes to identifying hybrid gulls, weasel words like "possible," "presumed," and "putative" are essential.

As always, comments are welcome.

 - Nick

Thursday, April 11, 2013

App Review: BirdSounds Costa Rica


While prepping for my recent trip to Costa Rica I was attempting to figure out the best way to put vocalizations onto my iPhone for use in the field. I started with a search in the App Store, not thinking I’d find anything useful at all, but was pleasantly surprised to find “BirdSounds Costa Rica” as a recent release. Jackpot!

Available for $19.99, BSCR boasts over 2,000 clips of 764 species (15+ hours worth!). It is produced and distributed by birdsounds.nl. As far as I can tell, BSCR is only available for iOS (not for Droid, at least as of yet).

My trip to CR was not a "birding" trip, so the amount of time spent using the app wasn't as lengthy as I would have hoped for, but by the end of the vacation I had a good feel for what BSCR was capable of. 

First, some important background information. Not all clips were recorded in Costa Rica. This is significant because vocalizations within the same species can vary, sometimes dramatically, from population to population. And if recent taxonomy has shown us anything, it's that these geographic vocal differences could represent several cryptic species. Thankfully, the producers of this app understand this and have included the locations of every recording - a fantastic feature! Importantly, recordist Peter Boesman of Belgium made a conscious effort to exclude songs or calls dramatically different from Costa Rican populations.

This app is very intuitive, so it should not take long to master all of its features. We are given four main buttons at the bottom of the screen: Browse, Recents, Favorites, and Info. We'll take a look one-by-one.

BROWSE


Here you can browse by First Name, Last Name, or by Group (which is the option pictured above). Where applicable, both common and scientific names are included side-by-side. At any point in these three browsing fields you can simply search for a particular species' name. The search engine narrows your results as you type letter by letter, which can save some typing once you see your target species pop up on the list. In other words, you rarely have to type out the entire species name.


The Search feature

Let's say we want to listen to Slaty-tailed Trogon. Once you select that species, this is what you see:


At the top left is a back arrow with the word "Browse" on it, which sends you back from where you came. Top right is the "+Favorite" button, which allows you to quickly add [or remove] this species to your list of Favorites (more on that later).

Just below that is a graphic representation of Song #1, the white background of which turns blue from left to right as the clip progresses. On the left of the graphic is the time elapsed, and on the right of the graphic is the time remaining.

You'll see that Slaty-tailed Trogon has three songs and two calls to choose from, which you select by touching the one you want (duh). If you want to see the background info on a call, touch the blue circle with the white arrow in it. Here's what you'll see for Song #2:



At the bottom left of the screen you have the play/pause button. Immediately right of that, the oval made of two arrows, is a button that allows you to set the order of your playback from the following four options: 
1) play all five clips to their end and then stop
2) loop through all five clips
3) play just the one selected clip and then stop
4) repeat the same clip until the user hits the pause button

Each of these settings can be useful in different field situations. I often find myself switching from mode to mode depending on what I'm doing.

RECENTS


This screen shows your 20 most recent species, with the most recent at the top. Also a super useful feature. These guys thought of pretty much everything. This list can be cleared anytime by hitting the "Clear" button at the top left.

FAVORITES

If you recall, while viewing any species page, you can tap the "+Favorites" button in the top right to add that bird to your list of favorites. A Favorites list can be useful in many ways. For example, one could set a list of species most likely to be encountered at a given site, making for quick study or field reference. Or you might set a list of target species for that day. Or nocturnal species you plan to "tape" while on a night walk.



You can click the "Edit" button to remove birds from the list. Species can be sorted by "first name" or "last name" via icons in the top right.

INFO

Any new user should go directly to the Info page for instructions on how you use the app. You'll also find a statement by recordist Peter Boesman, and a brief list of places to stay in Costa Rica based on the recommendations of the recordists/producers.




Now that we've gone through each mode, let's discuss how this app performs.

Most of the recordings are of fine quality. They are clear with only the stated species calling loudly. A few recordings do have other birds calling loudly in the background, which can be quite confusing if you aren't already familiar with that species' vocalizations, but this does not happen very often. White noise is an issue in some tracks, but generally only when speaker volume is maxed out.

The library is an impressive one. In the field I did not find any species missing that I was looking for, although more extensive use may reveal some holes. Tubenoses are not included, which is understandable.

Nor did I notice any misidentifications, though my knowledge of CR bird sounds is so limited that I would not be the person to find many mistakes. If anyone reading this finds any misIDs, please make a note in the Comments section below (and better yet, contact the producers).

If I had to critique further, I would have left out the songs of wood warblers that breed in North America, if only to save space. This app isn't a small one; it takes up a whopping 1.02 GB on your iPhone, so including several songs that are rarely/never sang that far from the breeding grounds seems an unnecessary use of space.

Overall, I highly recommend BirdSounds Costa Rica for anyone who plans on birding there (or possibly in nearby countries as well, if no other option is available). It is extremely useful as a study aid before your trip, to confirm field identifications, or, if you're so inclined, to use as playback in the field.

 - Nick

Monday, April 1, 2013

Back in CT

I've been pretty quiet for the past few weeks, but that's not for lack of getting out. I've actually been too busy, in a good way. I spent 9 days in Costa Rica with family, then was back in town for one day before heading back out of town for the holiday weekend. It's been an odd year for me birding-wise. My CT year list stands somewhere around 70 species (!), revealing just how little local birding I've been doing. My schedule should settle down for a bit, allowing me to get out more locally as the spring progresses. I hope to get to the coast while some gulls are still around early this month.

While Apil in New England is often viewed as the calm before the migration storm that is May, there are plenty of rarities possible as our common arrivals trickle into the region. You can just check the nationwide RBA to see that Old World shorebirds are hot right now, with sightings of Spotted Redshank (IN), Black-tailed Godwit (VA), northbound/wintering Northern Lapwings, and Ruff (the first of what should be several) being seen by many. There was also a quiet report of a Common Snipe from Maryland while I was away, but I have not had the time to look for description and/or photos of that bird. Also in season are rare waterfowl; seems like a good year for Tufted Duck in the northeast, and we're now into the Garganey window...so check teal flocks (especially Blue-winged) for this super rare species. The list could go on, including southern overshoots, small gulls, etc etc.

As for the past few weeks, I have some stuff I'd like to get up here, including a few things from Costa Rica (despite it being a non-birding trip), book reviews, app reviews, and even some gulls from our Pac NW trip back in January.

 - NB