RED-EYED VIREO (Vireo olivaceus) REVI Sample size: 1,293 |
|
|
A common woodland songbird of deciduous or deciduous/coniferous forest, the Red-eyed Vireo breeds from British Columbia south to Washington and southeast to east Texas. In the east, it ranges from south Newfoundland to Florida in suitable habitat. Densities are higher in forest interior [Cimprich et al. 2000 (BNA)]. Red-eyed Vireo is usually single-brooded, the nest suspended in the fork of an outer branch above 2 meters [Sutton 1949]. The main food item is insects, particularly caterpillars, captured by gleaning and short flights through branches and understory vegetation [Robinson and Holmes 1982]. In winter they mostly eat fruit [Ridgely and Tudor 1989], foraging anywhere from treetops to lower vegetation layers of all forests from 3,000 m to sea level, including mangroves [Mayer de Schauensee and Phelps 1978]. The winter distribution of the North American (V. o. olivaceous) group is in South America, east of the Andes, in the Amazon R. basin from eastern Colombia to western Brazil [AOU 1998].
Migration is nocturnal, this species being among the most commonly killed in Florida at lighted towers, e.g. 280 in a single night at Jacksonville [Stevenson and Anderson 1994]. Migration stopover habitat is in any forest (preferably deciduous) or tall scrub habitat. Spring migrants leave South America in March and April, flying around the edge of the Gulf of Mexico, or from Mexico across the Gulf to the south U.S. by April, peaking in New England in mid-late May [Cimprich et al. 2000 (BNA)]. Fall migration peaks in Massachusetts in September and early October [Veit and Petersen 1993], and the U.S. Gulf coast by late-August and September [Cimprich et al. 2000 (BNA)]. Orientation experiments suggest that Red-eyed Vireos fly south both around and across the Gulf of Mexico [Sandberg and Moore 1996].
While the Breeding Bird Survey data show statistically significant increases in eastern populations from 1966-1994, this should be interpreted with caution due to the species' sensitivity to large clearcuts, forest fragmentation and brood parasitism by Brown-headed Cowbirds [Cimprich et al. 2000 (BNA)].
|
|
 |
Observations
This late spring migrant was commonly, and rather evenly detected in most A, B and C sites, with 2 exceptions. The unique Silver Maple floodplain forest of the CT A sites was almost totally avoided; and secondly, one extremely high total of 62 birds in one MA C site in 1996, greatly affected the overall figures.
Few migrants arrived until period 3, and totals then increased through periods 4 and 5. Red-eyed Vireos were thus such late migrants in the Connecticut River valley, that we did not see any decline in numbers by early June. It is assumed that although this species is an extremely common breeder in the valley, many of the birds may have been passing through until at least mid June. Some may have been bound for the far northern parts of the eastern breeding range, from James Bay (S Hudson Bay) to the Gaspe, N Nova Scotia and S Newfoundland. |
|
|
|
|
REVI Map
|
|
|
