Insight: Birds don't read the weather maps

April 30: Last night, after carefully studying all the weather maps, I predicted that the next big flight of migrants would arrive in NW Ohio no earlier than May 2.  The weather last night didn't look favorable for migration here: winds were from the east, or even the northeast, with some rain in the latter part of the night.  But despite that, people who were out early this morning reported an excellent arrival of migrants, with numbers of Baltimore Orioles and Rose-breasted Grosbeaks, and a big increase in the variety of warblers present in the area. 

So why was the prediction so far off?  One possibility is that we're reaching the point in the spring at which birds will go ahead and move without waiting for ideal conditions.  Especially these mid-sized songbirds, like orioles, grosbeaks, Gray Catbirds, and Great Crested Flycatchers, all of which arrived in numbers today, may be able to migrate as long as they're not battling strong headwinds.  It's also quite possible that the winds above 1000 feet were different from what we experienced on the ground - those winds may have been southerly, like the prevailing winds in areas to the south of us last night.  Whatever the reason, today was a good reminder of the fact that we can't always predict what will happen with the migration.

Question: Yellow Warbler - arrivals vs transients

Yellow Warbler: As a general impression, the local males show up on their summer territories before we start to detect many at the migrant traps along the lake. Is this an illusion, or does it reflect the actual pattern of their migration? Photo by Kenn Kaufman.

April 26 (Audubon's birthday): Here in the region of the Lake Erie shoreline, the woodlots or "migrant traps" along the immediate lake shore have such a concentrating effect that we usually detect migrants there before we start to see them elsewhere in the vicinity.  An exception to this pattern involves Yellow Warbler, which is one of the few warblers to nest commonly in this area.  My impression from past years -- borne out by observations the last few days -- is that male Yellow Warblers show up on their nesting territories a mile or two south of the lake first.  Today they were singing vigorously in several spots south of the Magee boardwalk, such as near BSBO and the Sportsmen's Center, but the first migrants are just now showing up at the boardwalk itself.

Does this mean that the birds that are going to nest here arrive first, while the transients going farther north arrive later?  Or are the local summer resident birds just a lot more conspicuous because they are singing and setting up territories? 

Incidentally, something like this happens with Willow Flycatcher later in the spring.  In the latter part of May, they suddenly show up on their territories in the scrub-shrub habitat around BSBO, and only a few days later they start to become conspicuous in the migrant traps right on the lake shore.  But again, the singing, territorial males are a lot easier to detect than the transient individuals.

So for the moment I have a question without a solid answer.  I suspect that local breeders are among the very first Yellow Warblers to reach this latitude, but I don't know that for sure, and I'll have to look into it further.

Question: Differential timing, sparrow version

Fox Sparrow (eastern, or "Red," population):  We know it's an early migrant, and that makes sense, but we don't know why some sparrows are later.  Photo by Kenn Kaufman.

April 22: Thinking today about two species of sparrows and their migration through NW Ohio.  Numbers of White-throated Sparrows are just now starting to build up, while the peak of Fox Sparrow migration is already well past.  This timing is already well known.  But I'm wondering: why does it differ so much between these two species?

White-throated Sparrows and the eastern population of Fox Sparrows have similar ranges in summer and winter.  They nest in boreal forests across Canada and winter in the eastern United States. White-throated Sparrow has a broader range at both seasons, with its breeding range extending well south into the northeastern U.S.and its wintering range extending north to the Great Lakes.  (Look at any field guide that has range maps to see what I mean.)  Still, their overall distributions are similar.  Hence my question: why do the Fox Sparrows move north a full month earlier, on average, than the White-throated Sparrows? 

Insight: In before the door closes

Male Black-throated Green Warbler: a few arrived in the area within the last couple of days, just before the wind shifted back around to the north. Photo by Kenn Kaufman.

April 20th: We've just had a couple of days and nights of southerly and southwesterly winds, and this evening the wind shifted back around to the northwest.  It looks as if it will stay that way for at least a few days.  But as a result of this recent weather pattern, we have a decent variety of birds around in northwest Ohio. 

This most recent push brought in very large numbers of Yellow-rumped Warblers and White-throated Sparrows, and lesser numbers of other typically early migrants, but it also brought a handful of species more typical of the end of April and beginning of May.  Lakeshore migrant traps like Magee Marsh and like the Black Swamp Bird Observatory main banding station a little to the east reported a few individuals of many species of migrants -- I heard reports of at least 20 warbler species being found within the last couple of days. 

This is a good reflection of the importance of noting numbers of individuals.  If we just reported a species list, it would give a very misleading impression of what's going on.  For example, we might list Yellow-rumped, Black-throated Green, and Yellow warblers.  But if we note that we saw 100 Yellow-rumped Warblers, 3 Black-throated Green Warblers, and one Yellow Warbler, it gives a better idea of what is happening with the migration.

Question: Where are these Avocets going?

Three of seven American Avocets (hanging out with Ring-billed Gulls) at the inland beach at Maumee Bay State Park, Ohio, on April 15, 2012. Photo by Kenn Kaufman.

Mid-April:  Yesterday while Ethan Kistler and I were on the hawk tower at Magee, he got a call from Sherrie Duris, who was over at Maumee Bay -- looking at 7 American Avocets.  These snazzy relatives of the sandpipers are generally rare in Ohio, so we couldn't resist running over to the park to look at them.

It's quite possible to go through a year of birding in Ohio without seeing any avocets at all.  But when they're seen -- and especially when they're seen in spring, I think -- they often occur in flocks, not as singles. 

This is mainly a western species.  It can be abundant on the Pacific Coast and on wetlands in the interior of the west.  It may nest as far east as the Dakotas and western Minnesota, and fairly small numbers spend the winter as far east as Florida and South Carolina.  But when I draw a line from any point in the winter range to any point in the breeding range, Ohio is not along that line.  American Avocets that show up here are not taking the most direct route.  Are they just wind-drifted off course, in flocks, every spring?  Or is there something else going on? 

Insight: First push of Broad-wings

A migrating Broad-winged Hawk comes low over the parking lot at the Black Swamp Bird Observatory in northwest Ohio, late in the day on April 15, 2012. Photo by Kenn Kaufman.

April 15: Last week I had predicted that we'd get a good hawk flight today, "including the first big push of Broad-winged Hawks for the year."  That was on another blog where I try to make predictions for the migration in n.w. Ohio; the link to it is here.

Of course, after I make these predictions, then I'm sweating it, hoping that they'll prove to be accurate.  Today, through the middle of the day, I was beginning to doubt that it would happen. 

Here in n.w. Ohio, good spring hawk flights happen mainly on warmer days with southwest winds.  The hawks are moving north on a broad front, but the southwest winds shift them toward Lake Erie; then they cut back to the west-northwest, paralleling the shoreline, until they can turn the corner at the western end of the lake and continue north into Michigan.  Today we had good southwest winds, but after some stormy weather overnight, nothing seemed to be happening with the hawks during the morning. 

Shortly after noon I went to the hawkwatch tower at Magee and spent half an hour.  I did see one Broad-winged Hawk and a few Sharp-shinned Hawks, but not much else, so I went elsewhere.  Sometime after 1:30, Ethan Kistler called me from the hawkwatch tower, to tell me that things were picking up.  I went back there to watch.  Ethan and I watched from the tower for a while, then went to Maumee Bay State Park, then to the west edge of Ottawa NWR, then after 6 p.m. we were back at Black Swamp Bird Observatory; everywhere we went for the whole afternoon, we saw Broad-wings and other hawks migrating.  It was definitely a major movement.

I think a couple of things contributed to the quality of today's flight:
1.  We had had northerly winds most of the time for more than a week before this.  Broad-winged Hawks are affected by wind direction, so they probably had been dammed up somewhere to the south of us, just waiting for a good day to move.
2.  Winds of about 20 mph by late morning were good for getting the hawks moving.  Later in the afternoon the winds were stronger, gusting to over 30 mph, and I think this was influencing the birds to fly low so that they were very easy to see.  On a calmer day, they might have been flying much higher.  Indeed, at Maumee Bay, the Sharp-shinned Hawks were flying only a foot or two above the ground or above the water in open spots. 

Question: Mergansers and merg answers

A female-plumaged Hooded Merganser, photographed in March in Ohio. Photo by Kenn Kaufman.

April 14: Lots of things happening today, but one observation left me scratching my head and wondering.  On the north side of the auto tour route on Ottawa NWR, scanning the rather secluded Pool 9 East, I found a good variety of ducks (including the only group of Northern Pintail that I've seen in the last few days).  I began to notice that the ducks included a lot of Hooded Mergansers. 

During the last week I had seen only a few Hooded Mergansers, in twos and threes, around tree-lined wetlands.  That made sense, because the species breeds locally in such situations, scattered through the swamps.  But here on this one pond, in a careful scan, I counted 57 of the birds.  That would be a large number for any time of year here, but especially at this season.  And of these 57 Hoodeds, not one was an adult male; all were brown birds, essentially female-plumaged.

At this season, adult female Hooded Mergansers in Ohio are mostly sitting on eggs at scattered sites, not flocking together on ponds, so I didn't know what to make of this.  After talking to Mark Shieldcastle (who knows a ton about waterfowl -- he was wetlands biologist for Ohio's Division of Wildlife for several years) and reading the Birds of North America account for the species, I'm guessing that these 57 Hoodeds may have represented a group of one-year-old, non-breeding birds.  They don't breed for the first time until they're two years old, and first-year males look similar to females.  (And some of these birds had a messy appearance to the head pattern, as if some black feathers had molted in among the brown, suggesting first-year males.) 

Still, I don't think there's a well-known pattern of young non-breeding Hooded Mergansers flocking together like this.  I have to wonder if they'll spend the summer in this area, or if they were on their way to somewhere else.  I'd be interested to hear from anyone who has some insight on this question.

Question: Waiting our tern?

Caspian Tern is commonly seen along the Lake Erie shoreline in northwest Ohio during the warmer months. But this year, at least, it showed up later here than it did farther east along the lake. Photo by Kenn Kaufman.

April 12:  Every day for the last 10 days, my birding time has included visits to hotspots on the Lake Erie shoreline in Lucas or Ottawa counties, n.w. Ohio.  I've been expecting to see Caspian Tern any day, and I finally did see one on April 11. 

Looking at the data on eBird, no one had the species much earlier in this area. (Tom Bartlett saw one on Sandusky Bay on April 10, and Ethan Kistler and Jeremy Ross both saw singles on Ottawa NWR on April 12.)  But just a little farther east along the Lake Erie shoreline, from Lorain to Cleveland, there were reports of singles and small flocks several days earlier -- going back almost 2 weeks, to March 28th.  Why would Caspian Terns show up earlier on that part of the lake?

The western basin of Lake Erie displays some notable differences in birdlife from the rest of the lake, with some deep-water birds like scoters being much more common farther east.  But I can't see why this would affect the timing of something like Caspian Tern.  Is this just a fluke, something that just happened this year, or is it consistent?  I'll have to see if I can find any data from past years -- or just try to document the timing carefully next year as well.

Insight: First Palm

Okay, I know, it's a terrible photo. This was a record shot, for documentation, and it was so freaking cold that my hands were shaking!  Photo by Kenn Kaufman.

April 10:  Among the earliest warblers to come through n.w. Ohio in spring is the Palm Warbler.  Their peak numbers occur in late April and the first few days of May, but we can hope to see our first one before mid-April if we get out enough.

Today I found my first Palm Warbler of the season, but it was notable in another way: it was of the eastern subspecies, the "Yellow" Palm Warbler (Setophaga palmarum hypochrysea).  These brightly colored birds nest mainly in eastern Quebec, the Maritime Provinces, and Maine, and they migrate north mostly along the Atlantic Coast, so they are rare in Ohio.  The vast majority of the birds that pass through here are "Western" Palm Warblers (Setophaga palmarum palmarum), which nest all the way from western Quebec to the edge of the Canadian Rockies.

"Yellow" Palms have been documented to migrate north earlier in spring than "Western" Palms, so perhaps it is not surprising that the first one to show up here would be a stray from this population.

Sources: eBird and BirdsEye

Early April:  This evening at the good shorebird spot on Benton-Carroll Road, along with 28 Dunlins, 61 Lesser Yellowlegs, 286 Pectoral Sandpipers, and others, I found a single American Golden-Plover.  (I found out later that Ryan Lesniewicz had seen the bird this morning, so it was here all day.)  This species is typically an early migrant, so I was expecting it to show up around this time, but I hadn't seen any reports of golden-plovers yet on the state listserve or the local RareBird forum. 

Of course I was curious to know what was happening with golden-plover migration -- were there others around?  Had they arrived elsewhere in Ohio?  As recently as a couple of years ago it would have been hard and time-consuming to find out.  Today I just fired up the BirdsEye app on my iPhone.  I may be biased in favor of this app, since I wrote some text for it, but it's incredibly handy for finding out what has been reported to eBird, the massive online database.  According to BirdsEye, no American Golden-Plovers had been reported anywhere nearby yet this year. 

Later at home, I went online and looked directly at the eBird website, digging around on "View and explore data," and found the same thing there.  Golden-plovers had been reported this far north even in late March, off to the west of here (the species migrates north mainly through the Great Plains), but this bird on Benton-Carroll apparently was the season's first in Ohio.  Being able to put my own sightings into this broad context of the total species distribution is a remarkable development -- it makes the whole experience of the migration seem more three-dimensional.

Insight: The social snipe

Early April: Wilson's Snipes are arriving in n. Ohio in good numbers, although they're not up to peak passage yet.  I'm seeing them in several areas with shallow water, including the flooded fields down on Benton-Carroll Road and a couple of the impoundments at the edge of Ottawa NWR. 

I saw my first Wilson's Snipes when I was ten years old, and I've probably seen thousands, even tens of thousands, at all times of year.  So I thought I knew the species well.  But I'd always thought of it as a solitary bird.  Walking into a marsh where snipes were common, I would see them flush singly and fly off as individuals, each on its own zigzag trajectory.  While many members of the sandpiper / snipe family are quite gregarious, forming large flocks in migration and winter, I had never considered Wilson's Snipe to be sociable at all.

Here in n.w. Ohio, where I've lived for almost 7 years, I've often seen groups of Wilson's Snipes foraging together during migration.  Gradually it's dawning on me that they will, in fact, form flocks.  Today at Ottawa NWR, a harrier made a low pass over a marshy impoundment, and a flock of 13 snipes flew out together, circled around several times, and then returned and landed together in the marsh.  No question, they were acting as a tight, cohesive flock.  So at least during migration, in Ohio, it's not accurate for me to classify them as solitary birds.