Ammodramus
This October, we had the good fortune to get looks at a
Nelson’s Sparrow. It was a rare opportunity to experience one of the most
secretive birds in North America. It marked only about the fourth time I have
seen one of these stunning, intricately marked, colorful seed foragers. Other
birders had found this individual on a farm about an hour south of us. The
orange-colored wonder has been there for about a week, a surprisingly long stay
this far north for a long-distance migrant, headed for the Gulf of Mexico or
the southeast coast of the US. They breed along the shores of Hudson Bay and in
the great plains in far northern Canada. Another race of Nelson’s breeds along
the coast of Maine.
 |
| Nelson's Sparrow, Tullando Farm, Orford, New Hampshire, Oct 2024. |
Nelson’s is in a distinctive group of sparrows that are all
beautifully patterned and maddeningly hard to see. I like to refer to them as
Ammodramus, a genus name that once contained seven similar-looking species.
(The name is no longer accurate, since taxonomic gymnastics has resulted
essentially in a split between Ammodramus, Ammospiza, and Centronyx. But
Ammodramus is a convenient shortcut name, if not entirely accurate. See J.D. Rising and D.D. Beadle, The Sparrows of the United States and Canada, p. 143.) Ammodramus is Greek for "sand runner," which would seem to refer to its habit of walking in marshes in winter.
In my early years of birding, I would flip through the field
guide and wonder about the things I still had not seen. The couple of pages of
Ammodramus seemed like a complete mystery. Their orange-tinged heads made them
look different from all other sparrows. They did not seem to come up in
conversation with birders because nobody had a reliable location to go see one.
All of them have a habit of staying hidden in thick vegetation in marshy areas
or in dense grasslands. It would be many years before I would manage to get
looks at them, always by way of information shared among birders.
The most common of the Ammodramus is Grasshopper Sparrow. It
also has the largest range, inhabiting most of the North American continent,
save for the areas that are grass-free due either to low rainfall or
overgrazing or both. In the 1980s-1990s, they were breeding birds at the Las Vegas National Wildlife Refuge,
a great place for birding not far from where I lived. This refuge is grazed by
cattle, but lightly, and it managed to hang on to some quite fine patches of
tall grasses. The decline of Grasshopper Sparrow at this location is
mysterious; I am guessing that some complex set of climate factors is to blame,
or some subtle shift in the species makeup of the grasses. But the sparrow can
still be found in many parts of the country. Sadly, however, surveys
demonstrate a national decline in numbers that is the subject of current investigation.
 |
| Grasshopper Sparrow. Ohkay Owingeh pueblo, New Mexico, April 2018. |
 |
| Grasshopper Sparrow showing its characteristic flat head. Ohkay Owingeh pueblo, New Mexico, April 2018. |
Seaside Sparrow, the least colorful member of Ammodramus, is reasonably reliable in Delaware marshes, but restricted to shoreline habitats to a remarkable extent – it never shows up anywhere else.
 |
| Seaside Sparrow, Marvel Saltmarsh Preserve, Delaware, May 2021. |
So that’s it. The rest of the Ammodramus fall into the category of Ridiculously Hard to See. They don’t move around or sing loud like other sparrows. They breed in far-away lands, and winter at scattered places in the Southeast where birders seldom go. On migration, they generally don’t stay in known locations. They stay under cover – like, all day, every day. They see birders approaching from a long distance, and start to ridicule us. “Hey, it’s about time to sit in this bush and preen for a while,” they think. “That dude with the binoculars doesn’t stand a chance.”
Saltmarsh Sparrow is so restricted in distribution now that I know of only one location for it: the Marvel Saltmarsh Preserve in Slaughter Beach, Delaware. This spot was saved from the bulldozer in the 1980s. Today it is a beautiful expansive stretch of saltmarsh, filled with bitterns rails, herons, and harriers.
 |
| Marvel Saltmarsh Preserve. May 2021. |
Stand on the boardwalk here and look out for the tiny shaking of a
branch that reveals a bird. I have heard them sing, or “sing,” only at sunrise
and well after sunset. The “song” is a strange, mildly insect-like exhalation of breathy sound.
(I suspect the song evolved to propagate in the frequent winds that blow.)
 |
| Saltmarsh Sparrow, Savage's Ditch, Delaware, November 2020. There are a few records here. |
Baird’s Sparrow, Henslow’s Sparrow, and LeConte’s Sparrow
are the midwestern members of Ammodramus. Baird’s moves south in the fall and
scatters into huge areas of scrub (or former Chihuahuan desert grassland) of
the American southwest and (mostly) Mexico. They like to stay on the ground
when wintering, and usually walk away from an approaching birder and disappear
between plants. This area has been devastated by livestock grazing, making the
birds even more scarce than they would otherwise be. My only sighting lasted a
fraction of a second, a bird scampering away from me after an five-hour search
in early January near Deming, New Mexico. Henslow’s Sparrow is rapidly declining because of grassland loss to agriculture and urbanization.
My only sighting was in far western Maryland, where coal mining sites have been
converted to artificial grasslands high in the Appalachians that seem to
substitute for their preferred prairie habitat.
LeConte’s Sparrow breeds in the Midwest (mostly Canada) and
winters in the American southeast, where it is so thinly distributed that it is
hard to locate. It may be the most beautiful species in a genus known for its
good looks. I have observed it only twice, when a migrant bird stopped for a
few days beside a hay field in Maryland, and when a few of them accidentally
found themselves beside a reservoir in eastern New Mexico for the winter
(thanks, Bill West). The species seems
to be holding its own in numbers, but then again, very little is known about it
and future research might paint a different picture.
 |
| LeConte's Sparrow, Mt. Pleasant Farm, Maryland, Nov 2020. |
Nelson’s Sparrow allegedly winters in the marshes in Delaware. But very few are actually detected each winter. I found my first one at a southern Delaware marsh known as Savage’s Ditch, when it raced ahead of me on a wet path and perched for a minute or two about a foot off the ground, on a mostly obscured perch. They occur annually in a marsh near Burlington known as Delta Park, but not when I have visited! So it was good news indeed to hear that we could enjoy the bird a second time at the edge of a large dairy farm in New Hampshire. This bird is using a tiny fragment of habitat, a muddy puddle where runoff accumulates and a few tall grasses grow beside a cornfield (yet another example of opportunism on migration). We stopped there and waited for a half hour, before it was betrayed by tiny movements of branches. Characteristically, it hopped just a few inches from branch to branch, and also walked a bit on the mud while looking for seeds. It never stayed in view for more than a few seconds. (I got photos only by way of a determined effort.) The golden color of the bird’s head seems to scream out “I’m not like the other sparrows.” This pattern is clearly camouflage for when it is wintering among brown stalks in the marsh. But its beauty is obscured by its habit of staying deep in the vegetation, and refusing to produce the kinds of chips that the common Song and Swamp sparrows give so frequently in the same habitat. Nelson’s Sparrows keep it quiet and mysterious.
The loss of marshes, especially salt marshes, is one of the most serious environmental problems of our time. I am still educating myself on the issue, especially on salt marsh restoration. Here is some of the latest information on measuring the loss of global salt marshes. And here is a small sample of information on what is being done to restore former salt marshes.