CORMORANT-A-MY-HOUSE

There was a recent, unusual sighting of Double-crested Cormorants in the Upper Deckers Creek watershed in Preston County, West Virginia. This is sort of like seeing a Prairie Chicken in Memphis, but anything is possible, I suppose.

A Cormorant is quite a bird, actually, and there are six species recorded for North America, the Double-crested one being by far the most common and is the only one you could expect to see inland around fresh water. I have seen four of these species.

The fish-eating Double-crested Cormorant lives in and around water and can be distinguished by its large, greenish-black plumage, a slender hooked-tip bill, orange facial skin, and webbed feet set well back on its body. It is named for the two small tufts of feathers on either side of its head, which appear on the adults in spring plumage. The bird can frequently be observed standing erect on rocks or posts, sometimes in a spread-eagle posture drying its feathers; or swimming low in the water, often with only its head and neck exposed. On the water, it can be distinguished from loons by the distinct upward angle of its head and bill.

This species has had its ups and down in the US interior. Although present in Lake of the Woods, Ontario for a long time, no individuals were seen in the Great Lakes until they began to colonize the western end of Lake Superior around 1913. This habitat was successful and the species spread eastward through the Great Lakes even to Lake Ontario. By 1950 everyone agreed that there had been a population explosion.

Initially there was a large outpouring of complaints from fisherfolk who felt these birds were competing for the desirable harvest species of fish, however wildlife studies on pellets and what not failed to support this claim. The preferred foods of these birds were alewife, perch, and rainbow smelt.

Still, control measures were instituted, some official and some not, and nesting success was greatly decreased. Soon though, natural nesting failure primarily due to eggshell thinning took over in the 60's and 70's and the Double-crested Cormorant population crashed. As with other fish eating birds, egg shell thinning was due to contamination of DDT breakdown products and PCBs.

Once DDT was banned and the toxicity and sources of PCBs identified and controlled, this species rebounded smartly. Oh boy did they rebound! Today we see another crest in populations of Double-crested Cormorants and the West Virginia sighting may have been a part of that.

As before, fisherfolk are complaining, but most of their concerns are not justified (the birds eat very few salmon fry for instance), but there is a great concern remaining that the populations are decimating pan fry species such as yellow perch and small-mouthed bass. It takes about a pound a day to feed EACH adult cormorant during nesting season.

Another documented problem caused by the nesting birds is the vegetative destruction caused by their nesting habits. These birds are colonial nesters and the combined weight of their nests result in breaking of limbs and even entire trees. Add to that the tons of excrement that befouls and kills herbaceous plants and you can see a huge environmental effect. This is especially a problem on small islands and this leads to subsequent erosion.

I lived for 8 years on the North Carolina Outer Banks and in that time I could detect annual increases in this species during the winter. Huge, huge numbers of birds spend the winter in the Pamlico Sound where they spend the night. In the morning they fly out and raft up in the ocean. Towards the end of my tenure there (early 00's), I would marvel on my morning trip south along the coastal highway and as I began my climb onto the lengthy Oregon Inlet bridge to Pea Island I could see enormous numbers of cormorants leaving their nightly habitat, flying east over the bridge to the ocean side. The flocks filled the sky in continuous lines from one horizon to the other.

Now something has to be feeding those enormous numbers of fish eaters and I do not know if the salt water species that feed them have been as well studied as the Great Lakes species. Also, what do you suppose the effects of all that poop has on the estuary? It is already assaulted enough with pig farm run off (a big lobby in NC).

So what is the next stop in cormorant natural history? Huge populations of these birds would not be welcomed in WV habitats like New River, Ohio River Islands, or Cheat Lake.

Stay tuned.