The 23rd Delaware Reservoir Christmas Bird Count was held on an overcast, cold December 19th. Thirty-five participants were divided into ten parties and collectively spent 99 hr. 57 min. in the field. Although we saw or heard 70 species, which is our second highest species count, we did not add any new species to our collective list. Nonetheless, we did pick up several unusual species. Darlene Sillick and Richard Stelzen observed a male Common Merganser on the sliver of Scioto River that is on the western edge of our count area, only the second time the species has been recorded on our count, but the first in 1993 was of 9 individuals. John Kuenzli and Tom Archdeacon photographed two Hermit Thrushes in Delaware State Park.  Hermit Thrush was first recorded last year.
The two weeks preceding the count were unusually cold and by count day only turbulent or fast flowing sections of the rivers were open. The consequence was that the diversity of waterbirds was low, only seven species, compared to an annual average of 9.3. Numbers of four of the seven species (Canada Goose, Am. Black Duck, Ring-billed Gull and Belted Kingfisher) were substantially below average, but Great Blue Herons were present in above average numbers, mostly clustered in areas of turbulence along the Olentangy River. Mallards were clustered in record numbers in open water south of the Olentangy dam and on the river at Mingo Park.
A scintillating spot were the numbers of woodland birds seen. Red-bellied, Downy, and Hairy Woodpeckers were all present in record numbers as was the rare Yellow-bellied Sapsucker, a record-setting two individuals. Hundreds of chickadees and almost a hundred titmice were the most ever seen on the count. Golden-crowned Kinglets were also present in unusually large numbers. In 2001 a sharp drop in American Crows and a year later in Blue Jays may have reflected the effect of West Nile Virus, but Blue Jays were present in large numbers in 2009 and 2010, an encouraging sign. Numbers of crows remain low, although marginally better than 4-5 years ago.  The House Finch population plummeted in 2002 coincident with an outbreak of conjunctivitis and remains essentially unchanged through the 2010 count. Goldfinches, which do not seem subject to conjunctivitis, have shown no pronounced fluctuation in the last decade and were present in average numbers on the 2010 count.
During count week, the three days before and after the count, several species not recorded on the 2010 count were seen by Bill Heck and Sean Williams. These include Cackling Goose, Red-shouldered Hawk, Sandhill Crane, and American Pipit. Only the Sandhill Crane has not been seen on a previous count, but it did not show up on 19 December 2010. Well, maybe next year when the count will be on Sunday 18 December.
| Pied-billed Grebe | 1 |
| Great Blue Heron | 40 |
| Canada Goose | 1098 |
| Am. Black Duck | 4 |
| Mallard | 999 |
| Hooded Merganser | 1 |
| C. Merganser | 1 |
| N. Harrier | 9 |
| Sharp-shinned Hawk | 1 |
| Cooper’s Hawk | 12 |
| Bald Eagle | 4 |
| Red-tailed Hawk | 51 |
| Rough-legged Hawk | 2 |
| Merlin | 1 |
| Am. Kestrel | 20 |
| Ring-necked Pheasant | 10 |
| Wild Turkey | 20 |
| Ring-billed Gull | 8 |
| Herring Gull | 2 |
| Rock Pigeon | 42 |
| Mourning Dove | 735 |
| E. Screech Owl | 2 |
| Gr. Horned Owl | 5 |
| Barred Owl | 4 |
| Short-eared Owl | 1 |
| Belted Kingfisher | 5 |
| Red-bellied Wdp. | 103 |
| Yellow-blld. Sapsucker | 2 |
| Downy Wdp. | 176 |
| Hairy Wdp. | 18 |
| N. Flicker | 32 |
| Pileated Wdp. | 6 |
| Horned Lark | 1470 |
| Blue Jay | 273 |
| Am. Crow | 160 |
| chickadee sp. | 279 |
| Carolina Chickadee | 3 |
| Tufted Titmouse | 94 |
| Red-br. Ntch. | 1 |
| White-br. Ntch. | 29 |
| Brown Creeper | 23 |
| Carolina Wren | 22 |
| Golden-cwnd. Kglt. | 36 |
| E. Bluebird | 30 |
| Am. Robin | 805 |
| Hermit Thrush | 2 |
| N. Mockingbird | 7 |
| Cedar Waxwing | 148 |
| E. Starling | 13755 |
| Yellow-rumped W. | 25 |
| N. Cardinal | 459 |
| Eastern Towhee | 9 |
| Am. Tree Sp. | 700 |
| Fox Sp. | 1 |
| Field Sp. | 3 |
| Song Sp. | 141 |
| Swamp Sp. | 11 |
| White-thr. Sp. | 117 |
| White-cr. Sp. | 69 |
| Dark-eyed Junco | 447 |
| Lapland Longspur | 2 |
| Snow Bunting | 138 |
| Red-winged Blkb. | 6 |
| Eastern Meadowlark | 1 |
| Rusty Blkb. | 2 |
| Common Grackle | 6 |
| Brown-hd. Cowbird | 3 |
| House Finch | 178 |
| Pine Siskin | 2 |
| Am. Goldfinch | 269 |
| House Sp. | 957 |
| Total individuals | 24098 |
| Total species | 72 |
| Observers | 35 |
| Parties | 10 |
| Total party hours | 99.95 |
| Owling hours | 0 |
| Party miles | 0 |