Ecology and behavior of the zenaida dove

Abstract

Data are summarized from a 10 year study of the Zenaida Dove (Zenaida aurita) in Puerto Rico and its offshore islands. The dove displays sexual size dimorphism, with males generally larger than females: Most activities (feeding, courtship, fighting) occurred in mornings and afternoons, whereas loafing and maintenance activities were more prevalent at mid-day. I recorded 77 plant species used as food by Zenaida Doves in Puerto Rico. Major food species uncluded Scleria lithosperma, Argemone mexicana, Croton rigidus, Phyllanthus amarus, Cordia angustifolia, Zanthoxylum martinicense, Euphorbia heterophylla, and several species of legumes. Zenaida Doves have two major vocalizations: the 'Coo', or Advertisement Call, given in assertive and sexual contexts, and the Nest Call, primarily used at or near the nest. Doves nested in a wide variety of habitats, including forest edge, mangrove forest, dry scrub, and mixed agriculture-urban areas. Nests were generally placed in trees, but doves nested on the ground where certain terrestrial predators were absent. Nests were found in all months of the year, although a breeding peak occurred from March through Mayor July. Doves replaced clutches when nests were destroyed, and recycled up to four times in a season. Males selected nest sites and initiated building. Eggs (2) were laid on alternate days, beginning about two days after the nest was completed. Incubation and nestling stages averaged 13.9 :t 0.5 [SE] and 14.3 :t 0.6 days. The male attended the nest from mid-morning (X = 08:59 hr) through mid-afternoon (x = 16:53), then the female took over incubation and brooding duties for the night. Nests were continuously covered from the laying of the first egg through day seven of the nestling stage. Thereafter, adult attendance dropped steadily until day 14, when they carne to the nest only for chick feedings. Chicks (days 0-15) showed a mean daily weight gain of 18.3% and attained a fledging weight of about 120g (81% of adult weight). The mean daily growth (culmen, tarsometatarsus, ulna) was 6.8% (range = 4.0-9.8% daily). Dove productivity varied among and within study areas over the 10 years. Mean number of chicks hatched per nest that held eggs ranged from 0.3 to 1.6 for 3 study areas. Mean number fledged per nest ranged from 0.3 to 1.4. Productivity was lowest in the dry southwestern Puerto Rico study area (Susua and Guanica forests; x = 0.7 chicks fledged per nest) and was highest for the lower montane mixed agriculture/urban area (Cidra; 1.2). Populations nesting in scrub and mangrove forests (Roosevelt Roads Naval Station) fledged an average of 0.9 chicks/nest. Nest success followed a similar geographic pattern: southwestern Puerto Rico -40.9% of nests with eggs were successful, Cidra -62.6%, and Roosevelt Roads -52.0%. The most important sources of dove egg and chick loss were Pearly-eyed Thrashers (Margarops fuscatus -49% of losses) and roof rats (Rattus rattus -16%).