Spring Shakedown 2014

Well, the calendar has turned, and we’re officially out of the spring migration season and into the summer breeding season. Of course, setting hard and fast calendar dates to define biology is really just for the fun of organizing things… birds have been on nests for sometime now, and I’m sure there are still migrants passing through the area.

But with the changing of the calendar, we certainly know what we can expect: fewer warblers to crane our necks at, fewer shorebirds to become flummoxed over, and more leaves to peer through something small and backlit singing it’s head off in the canopy. I started thinking about this year’s migration season, and how it might have compared to years past. Particularly last year- as these two migrations couldn’t have felt more different.

Maybe it was the numbers of birds we got to see as a group, maybe it was the excitement of the fall-outs, or maybe it was some other enigmatic or abstruse reason known only to the moon and stars. This year felt thin, like we weren’t seeing the warblers and tanagers we did last year. Certainly last year we were spoiled rotten, but this year seemed very lean, with just a few individuals at Brison or County Club Lake at a time. If they were even there!

Whatever the reason, I wanted to look at some data. Numbers always soothe my mind- or at least confound it. And sometimes I can glean little nuggets of interest for extra perspective. This year continued our recovery from the drought of 2010–11, the rainfall kept the lakes in town pretty full.

Look at the drop in rain in 2010 AND 2011! Bad times.

So a few things came to mind right away- could have been the weather, sightings reported, or maybe there just weren’t that many species that came through town.

Weather

Weather is obviously a complicated thing, and really drilling down into the details of trans-Gulf weather patterns over a three-month period is beyond the scope of my evening!

But I did have a look at the general wind patterns for the time period, and noticed some interesting things going on. I used Weather Underground’s Almanac to browse through the relevant weather data to see if I could explain our “understated” migration. Our great 2013 Spring (particularly April and early May) seemed to be partially a function of the timing of the winds… repeatedly, we had a good wind shift late in the work week, leading to lots of birds to be seen weekends (blue dots). Convenient! April and May of 2014 had some wind shifts, but not as cleanly and not as dramatically as 2013. 2014 had lots of winds from the East or the West… but it seemed to lose that North/South polarity.

Wind direction during the Spring migration season, 2013 and 2014... the storms are easy to spot!
Weekends are circled in blue.

This wind direction/weekly pattern starts to show some payoff for us when you add in the number of species seen each week. Late April and early May start really racking up the numbers!

I’ll caution here that two years of data do not make a trend! So it’s an interesting observation, but we’ll need more years of data (and more years of quality Ebird sightings) to really get a idea of this relationship.

But we can say weather played a part. How much? I’ll let the folks that get paid to work on it figure it out.

Sightings

I took to Ebird to see what I could dig up. I know not everyone used Ebird, but it has enough usage to give a glimpse into what everyone is seeing around here. For clarity, I kept my searches limited to Brazos County, March–May only.

What about reports? Maybe we didn’t really report things like we did last year? I mean we were out, but maybe we were so sad by not getting 20 warblers in a morning, we just couldn’t bear to report it. The numbers don’t lie: there were 451 reports in 2013, and 611 reports in 2014! Wow! That’s a lot of reports! Ok, it wasn't for a lack of reporting.

Birds Varieties

Well, what then? Did we not have the same variety of birds to look at? Maybe all of the good birds just passed us by for the promise of the great Northern wilderness?

The birds! The birds!

Wait, what? We were only 3 Species short of last year?!?! That’s not what I expected! Well, it must have been a bunch of extra junk birds, right? I’m sure we had more migrants – like warblers and shorebirds – last year than this. Well…

Warblers: 30 in 2013, 31 in 2014!

Shorebirds: 42 in 2013, 37 in 2014!

See the list below if you don’t believe me.

And these are just the ones that were easy to see!

So, maybe I was a little generous with my shorebirds definition, including gulls, terns and gallinules. But I don’t think that changes the overall trends. We had plenty of good birds in 2014 – it just took a little more hunting and driving to go get them!

I’ve got the entire list sorted out if you’re looking for something to do other than what you’re supposed to be doing (like me!). Data is divided by birds Common to both years, Unique to 2013, and Unique to 2014. Or you could just check the Ebird lists for 2013 and 2014.

I didn’t have a chance to look at numbers of birds reported- I couldn’t get that out of the downloadable data from Ebird. I suspect it would reflect what we saw, lower numbers of individuals this year vs last.

Another thing to remember is the health of the habitat and the places we bird. Country Club Lake was teaming with reeds and grasses last year, which of course brought in the American and Least Bitterns, Virginia Rail, and Soras. It was also considerably lower, so there were ample shoreline for the sandpipers to explore. This year, a high water line and almost no vegetation really knocked that park’s numbers down. Although we did have an American White Pelican and White-faced Ibises there, so it wasn’t completely devoid of migrants, but not nearly the variety we’re used to.

This lack of convenient shorebird habitat did lead to some interesting finds. The value and diversity for couple of other lakes and marshes south of town were highlighted too - the ponds at Peach Creek and TX-6 had a number of good ducks, and the marsh across from the Cox Cemetery yielded both Gallinules this spring! There have been some great sightings from the Allen Farm area – either random big puddles, or irrigation holds- Hudsonian Godwits, Wilson’s Phalaropes, Long-billed Dowitchers, Black Terns, and more!

The big picture idea here is that migration birding can be tough, but that doesn’t mean it isn’t rewarding (and remember: tough birding = good flying = more birds on breeding territory!). Our combined efforts were impressive, considering all of the good flying days in 2014. It will be important going forward to keep an eye on our known migrant stop-overs for signs of neglect or deterioration too. Losing habitat is the best way to ensure tough birding, no matter what the weather.

Oh, and since I had an entire post about migration without a picture a of bird, and our speaker this month is one of the best bird photographers around (Greg Lavaty), here's a couple of quick pics of a bird and a bug. I'll let you ID them!