October 2008


While banding birds at Bob Thobaben’s farm west of Wilmington, OH, we caught a series of Field Sparrows with curious growths on their feet.  The first one we caught, we merely noted the presence of the growth.  An hour later, we caught another Field Sparrow with a similar growth.  Sensitized to the problem, we took some pictures of this bird.  Fortunately, it was a retrap.  Bob’s records showed that the bird had been banded only three weeks before.  No unusual growths were noted at that time.

Growth on second bird.  Right leg, ventral side

Left:  Growth on  right foot of second Field Sparrow, ventral side.   Right:  Same growth as seen from left side.

On the next round of the nets, we found still a third Field Sparrow.  This one had four growths of the same sort, two on each foot.

Left:  Third bird showing two growths on each on foot.  Right:  The whole bird.  The growths are barely discernible  at this scale

The growths are about a half a centimeter in diameter and look rather like oak galls.  Bob says he has not see anything like this in thirty years of banding.  Anybody out there know what this is?  How do we account for such a concentration in time, space, and species?  Also, these growths appear to be fast-growing.  What is the cause of that?

Science is all about questions.

Juvenile robins battle for a turn at the water

Juvenile robins battle for a turn at the water

For the past two years, my wife has run this jury-rigged bird bath.  She hangs the hose over a convenient limb and lets the water drip into a horse feed pan.  The assemblage is completed with a couple of bricks that allow the birds to stand ankle deep in the water for drinking and bathing.

All of the birds in this picture are robins and all retain some spots on the breast indicating that they have not yet completed the molt into their first set of adult feathers.  The second photo shows a close-up of the juvenile plumage.  During the month of September, most birds molt into the familiar red breast.

Young robin with speckled breast.  The breast will turn red by the end of September

Young robin with speckled breast. The breast will turn red by the end of September

In the late summer both this year and last, we have noticed absurdly large collections of juvenile robins using the bird bath in September, virtually to the exclusion of adult birds.  The second most numerous users are juvenile starlings, followed by juvenile cardinals.  It is not as if the adults are absent—we still have plenty of them at our feeders.

Our question is why the juveniles love this birdbath so much and why the adults are absent.  Might it be as simple as the adults being more cat-savvy than the kids?    Anybody got any ideas?

Though noted in  many species, the phenomenon of post-nuptial wandering is particularly pronounced in birds that breed in large colonies, possibly as a response to habitats that have become depleted in raising numerous broods.  Surprizingly little has been published in the scientific literature about post-nuptial wandering, but it is eagerly anticipated by northern birders as an opportunity to see long-legged waders from the Deep South in our own back ponds.  This year threw up a real rarity, a trio of Wood Ibis, only the fourth record of this species in Ohio.  Oddly enough, two of those records are from Clinton county, scant miles from Congress Farm.

The storks appeared in a quiet forest pool in Cochocton county in the Wills Creek drainage.  They were first reported by Robert Schlabach on 26 Aug and were last seen by Robert McNulty on 8 Sep.  In the meantime, the birds remained very predictable and were viewed by dozens of birders from Ohio, West Virginia, Pennsylvania  and Kentucky.

The birds were all juveniles, showing much more feathering on the head and neck than is usual for adults.  There was also a considerable amount of muddy brown color on the neck and on the upper back.  The two photos below contrast the Coshocton birds with an adult photographed in the Everglades in 1998.

The Coshocton county wood storks, 28 Aug 08

The Coshocton county wood storks, 28 Aug 08

Adult Wood Stork in the Everglades, May 1998

Adult Wood Stork in the Everglades, May 1998

Note that the head and neck of the Everglades bird are completely bare and the plumage is completely white except for the black primaries.  The details of the juvenile Coshocton birds can be better seen in the following pictures.

Coshocton Wood Storks foraging.  Note "fuzzy" feathers on head and neck on mud-colored tracts on neck and upper back.

Coshocton Wood Storks foraging. Note "fuzzy" white feathers on the top of the head and mud-colored patches on neck and upper back.

Spread wings indicate fully adult wing pattern of black flight feathers and white coverts.

Spread wings indicate fully adult wing pattern of black flight feathers and white coverts.

These storks were very active and amazingly tolerant of birders.  They often foraaged fairly close to the road from where we were parked, allowing great opportunities for photography.  The foraging technique included shuffling the feet in the mud, presumably to stir up prey.  The birds also swept their bills along the bottom.

Coshocton storks foraging in shallow water.

Coshocton storks foraging in shallow water.

On several occasions, we and other observed one of the birds extending a wing in a maneuver similar to the characteristic shade feeding of Reddish Egret.  (The Black Egret of Africa also has a shade feeding technique, but it is much more exaggerated.)  My feeling was the the wing extensions I observed were reflex actions to maintain balance.  Young birds are often clumsy (see Pileated Woodpecker post below).  I believe these birds just lurching about on a bottom that probably differed greatly from what they were used to in the Everglades or the Gulf Coast.

These young birds were good, efficient foragers.  We observed a number of successful captures like the one below.

Wood Stork nabs a crawdad

Wood Stork nabs a crawdad

We were really lucky to have the opportunity to observe this species so closely in such an interesting plumage.  The only other verified reports (according to Peterjohn) date back to 1909 and 1946, both immatures in the Wilmington area, and two birds in Ashtabula county in 1955.  So it might not be too hyperbolic to say that this was once in a lifetime opportunity for Ohio birders.