Birdwatch By Susan Campbell

Cleanup on Aisle 2

T h e vulture’s rol e in th e ecosyst em

By SuSa n Ca m pBel l Vultures: All of us have seen them. Maybe it’s been passing a group feasting on a recently killed animal by the side of the road. Or, more likely, you have spotted an individual soaring overhead on long, outstretched wings. These odd looking birds are too often misunderstood and even disliked — for nothing more than their appearance. In actuality, they are fascinating creatures that perform a vital role in the ecosystem: They are Mother Nature’s cleanup crew.

Of ten refer red to gener ica lly as “buzzards,” v ult ures are par t of a family of birds found worldw ide w ith dozens of species, including South A mer ican condors. Here in Nor th Carolina, we have both t urkey and black v ult ures year-round. Indiv idua ls f rom far ther nor th sig nificantly boost flock numbers in the cooler months. T hese large black scavengers lack feathers on their heads: likely an adaptation to feeding a lmost exclusively on carcasses. Turkey v ult ures are the more common species f rom the mountains to the coast. Soar ing in a dihedra l (v-shaped profile) on long w ings w ith silver linings, they have red heads and long tails for steer ing.

Black v ult ures, however, have g ray heads and white patches on the under-w ing as well as somewhat shor ter w ings and tails. A s a re sult, they soar w ith a flat ter profile and fly w ith snappier w ing beats. T his species has rea lly expanded across the Piedmont in recent years, perhaps due to development, increased road building and the inev itable roadk ill that results.

T he w inter br ings v ult ures together in what can be impressive roosting agg regations that are k now n as “wakes.” T hese g roups can build to 10 0 or more indiv idua ls of both species that w ill roost close together in a par ticular spot: night af ter night dur ing the season. L ate in the day, they w ill gather in mat ure trees w ith larger branches capable of holding sig nificant weight. It is easy to spot them on ta ll snags or sit ting side by side on communication towers. Given the human tendenc y toward neatness, there are fewer and fewer dead trees for the birds to utilize — so they have been forced to use manmade perches. T hey may choose roof tops and this can, believe it or not, include people’s houses.

It is not obv ious as to why they choose the locations that they do each w inter. Given the ease at which they roam in search of food, proximit y of their next mea l seems rarely a concer n. T hey are capable of gliding and soar ing many miles each day. No doubt they require a location w ith a substrate that war ms readily in the mor ning sun to prov ide the updraf ts they require to reach cr uising a ltit ude. Vult ures do need a perch that is open enough to a llow them to spread their w ings on takeof f. T his is likely why they are found roosting in more open env ironments.

For those liv ing near a v ult ure roost site, be aware that the birds seldom use the same location for more than one season. T his could be for reasons of cleanliness or to perhaps reduce the chances of predation — but we rea lly do not k now. A lso, do not expect that the wake w ill persist beyond early spr ing. T he g roup w ill break up and head of f to their breeding g rounds by late Febr uar y or early March. Using prevailing southerly breezes, they w ill be car r ied back nor th in shor t order.

A lthough we do have sma ll numbers of breeding v ult ures in the Piedmont and Sandhills of Nor th Carolina, they are w idely dispersed and are quite secretive dur ing the nesting season. Unless they are on the w ing, snif fing out (yes, they use their noses more than their eyes) their next mea l, they may go completely overlooked. PS

Susan Campbell would love to receive your wildlife sightings and photos. She can be contacted at susan@ncaves.com.