Connecticut Warbler Oporornis agilis Scientific name definitions

Jay Pitocchelli, Julie L. Jones, and David C. Jones
Version: 2.0 — Published June 2, 2023

Diet and Foraging


Primarily forages on or near the ground in dense undergrowth where it gleans arthropods; occasionally eats fruits and seeds during migration. Diet on the overwintering grounds is poorly known and deserves further study.


Microhabitat for Foraging

Few specific details due to difficulty to observe foraging birds. During breeding period, forages on or just above the ground (196), on fallen logs (10), and in brushy sheltered areas around swamps and meadows (196). In migration, generally seen foraging on the ground in leaf litter or in dense brushy tangles or dense weedy areas, but may also forage along tree limbs well above ground (11); e.g., during fall migration in Massachusetts, reported to forage in the tops of large willows (Salix), 15–20 m above ground (111). During migration in Puerto Rico, it has been observed feeding at the base of mesquite brush piles (119). On overwintering grounds, it forages low to the ground in dense undergrowth (197, 198).

Food Capture and Consumption

Information needed. While walking on the ground, bobbing its head back and forth and often peering upward, it frequently gleans prey from the underside of low foliage, often stretching or jumping vertically capture prey; it also gleans prey from leaf litter or branches (11). Bent (7) recounted an observation reported by Audubon of two Connecticut Warblers chasing a spider species that runs over water, capturing them while flying low over the water in a manner similar to that of a drinking swallow (Hirundo).


Very little is known about diet at any season.

Major Food Items

On breeding grounds, reported to eat spiders and insect adults, larvae, and eggs; also fruits during summer (199); as many as 50 spiders were found in the gut of one individual (7). Other food items mentioned include beetles, snails, and sometimes small seeds and berries (7, 142). Fed on late instar larval stages of the forest tent caterpillar (Malacosoma disstria) in aspen and mixed-wood forests in Alberta; caterpillar predation increased with increased numbers of Connecticut Warblers (88).

Information needed on diet during migration and overwintering periods. During migration in Puerto Rico, fed on Noctuid caterpillars (Mocis latipes) (119).

Quantitative Analysis

Information needed.

Food Selection and Storage

Information needed.

Nutrition and Energetics

Information needed.

Metabolism and Temperature Regulation

Information needed.

Drinking, Pellet-Casting, and Defecation

Information needed.

Recommended Citation

Pitocchelli, J., J. L. Jones, and D. Jones (2023). Connecticut Warbler (Oporornis agilis), version 2.0. In Birds of the World (P. G. Rodewald, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.conwar.02