Question: value of phragmites?

Phragmites (Common Reed) - Often a damaging, invasive weed in Ohio marshes, but potentially also a food source for some wintering birds

December 24: Today I was reminded of a question that first occurred to me a couple of years ago.  I was birding along the edge of a marsh north of Oak Harbor, and I flushed a flock of about 30 American Tree Sparrows from a big patch of phragmites.  I've found flocks of these sparrows in this habitat before; are they mainly using it for cover, or are they actively feeding on the phragmites seeds?  

Phragmites australis itself is a problematic plant.  The species is native to North America, but in recent decades it has become dangerously invasive in many regions.  Here in northern Ohio, marshes that used to be varied and full of life have turned into solid stands of phragmites, crowding out other plants and supporting relatively little wildlife.  Research has shown that the invasive phragmites is actually an alien strain, introduced here from other continents.  Managers of some wildlife areas in Ohio have gone to great effort and expense to control phragmites, to maintain some room for other species.  

Of course, some species of birds will find a way to take advantage of almost any plant.  Tall, dense stands of phragmites provide a certain amount of shelter for birds in winter.  I've often found flocks of American Tree Sparrows in such places.  Once when I had time to watch such a flock for a while, I saw that the birds were actually perching on the tops of the swaying stalks and evidently feeding on the seeds of the phragmites.  Today I watched the birds to see if they would do the same thing, but apparently I had approached them too closely; they would not go back to feeding while I watched, and eventually they flew farther away to an area where I could not follow.  So this will be a question for future observation.  American Tree Sparrows are very common near Lake Erie in northern Ohio in winter; how important are the stands of phragmites as a food source for them?  

Question: Flocks of Pied-billed Grebes?

This is just part of a flock of 97 Pied-billed Grebes seen at Metzger Marsh on September 21. The species is common here, but I haven't noticed this flocking behavior before. Photo by Kenn Kaufman.

September 21: Metzger Marsh Wildlife Area was loaded with Pied-billed Grebes during this nesting season, and I frequently saw and heard good numbers when I visited in May and June.  But today I was surprised to see a flock of Pied-billeds.  They were near the outer dike of the marsh, concentrated in one straggling string, and I carefully counted 97 individuals in this group.

I'm accustomed to seeing flocks of some other kinds of grebes.  Out in western North America, Eared Grebes regularly gather in large flocks on lakes, and Western and Clark's grebes will flock up on lakes or on coastal bays.  But with a marsh-dweller like the Pied-billed Grebe, I don't recall ever seeing such a concentration. 

It's possible that recent activity by anglers and hunters in the marsh has spooked the grebes out into this more open area of the impoundment, but I don't know that.  In addition to the flock of 97, I did see other scattered singles closer to the areas of dense vegetation, so at least some of the birds were acting the way I "expected" them to.

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? 

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? 

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.

Question: Are Tree Sparrows facultative migrants?

American Tree Sparrow: Strictly a winter bird in Ohio, leaving in spring to go far to the north.  How much is its departure time affected by local weather?  Photo by Kenn Kaufman.

Late March: Today I'm thinking about birds I'm not seeing.  For the last couple of years, I've seen small flocks of American Tree Sparrows around Oak Harbor throughout the winter and into spring, at least into early April.  There were plenty of them around this winter, but most of them seem to have disappeared in early March, about the time we started having record-warm temperatures.  Was their departure partly a result of the weather?

Researchers who study migration talk about different bird populations being obligate migrants -- those that move at a certain time of year, regardless of what the weather is doing -- and facultative migrants, which can vary the time of their migration (and even the distance that they migrate) depending on the conditions of the moment.  These are not two completely distinct groups, but rather two ends of a spectrum.  Most facultative migrants only vary their migration within certain limits -- that is, they won't suddenly start to migrate south if there's a cold day in June; the conditions have to fall within the right general time of year.

The most obvious examples of facultative migrants around here are various waterbirds, especially ducks, in their fall migration.  Many of them will come south to northern Ohio in fall and then linger as long as there is enough open water.  If it's a mild winter, they may stay the entire season.  Sandhill Cranes respond to weather also, so recently they've been migrating south later and later in fall, and staying through the winter farther north than they used to.

My question of the moment involves American Tree Sparrows.  Their breeding range is far to the north of here, in arctic and subarctic Canada and Alaska.  In a typical year, most will be gone from northern Ohio by mid-April, and almost all of them by the beginning of May.  This year, with record high temperatures for days at a time in March, the Tree Sparrows seem to have disappeared a month earlier than usual.  Did they, in fact, start north so much earlier?  I will be interested to find out if areas north of the wintering range had earlier spring records than usual.

Question: Are some Killdeers migrating in pairs?

Killdeer in flight: is it flying solo, or with a friend? Photo by Kenn Kaufman.

Early March: Killdeers just started showing up in the area a few days ago.  I've seen them at about a dozen spots.  The thing that strikes me about them is that all the Killdeers I've seen have been in pairs.  So the question is: do they go through their courtship and form pairs very rapidly after they get here, or are they actually pairing up somewhere to the south of here, and arriving together? 

Killdeers don't leave northwest Ohio for very long.  Usually a few linger locally until mid-December, and the first returning birds are back by mid to late February.  They're common in winter just a few hundred miles to the south.  It would be plausible for them to form pairs on the wintering grounds.  The Birds of North America account for Killdeer doesn't shed any light on this.  It does say that Killdeers in the South may remain in pairs all year, and that those in the north may have the same mate for several years in a row. 

I guess I'll have to watch the arriving Killdeers more closely next year, to see if there's active chasing and courting on the day they arrive, or if the birds come in looking like established couples already.  But I'd be interested to hear from anyone who has more insight into this question.