Snail kites are most frequently seen flying over bodies of water and wetlands. Their flight is low and irregular because they are hunting for apple snails (Hilty et al., 1986). Snail kites may also be seen looking for prey from perches. When the hunt is successful, handling times are long because they must extract the body of the mollusk from its shell, so snail kites are also commonly seen on perches performing this activity (Bergmann et al., 2003). In any case, snail kites are usually with other individuals of the same species or interacting with other species (Sykes, 1987).
Snail kites defend small territories around their nests but do not have a larger foraging territory, so foraging areas of different pairs may overlap. Observations describe the females as more active than the males in defending their nests by making vocalizations or engaging in active pursuit of the invader (Sykes, 1987).
Reproductive pair bonds form as the male begins to build a nest, so in courtship displays the male generally carries a stick for nesting material. Displays are performed close to the nest, in flight or on a perch, and also include vocalizations (Sykes, 1987). Aerial displays are categorized into six different movements in Sykes (1987): pendulum, grappling, tumbling, mutual soaring, and undulating and slow flight.
Copulation occurs when receptive females are fed by the male and then crouch in order to be mounted by the male (Sykes, 1987).
Both males and females attend to the nest throughout the different reproductive stages of nest construction, incubation, and feeding of nestlings. However, a study of energetic demand and behavior evidenced that males feed their mates more frequently than females and also are more engaged in nest building (Beissinger, 1987).
Social and interspecific behavior
Snail kites amply interact with other individuals from the same species or different ones in colonial groups over the marshes they inhabit. During reproduction, they build nests in loose colonies with other breeding pairs of waterbirds such as anhingas (Anhinga anhinga), Red-winged Blackbirds (Agelaius phoeniceus), Common Yellowthroat (Geothlypis trichas), grackles, moorhens (for example Gallinula chloropus) and various species of the family Ardeidae like Great Blue Heron (Ardea herodias), Great Egret (Ardea alba), Snowy Egret (Egretta thula), Little Blue Heron (Egretta caerulea), and Tricolored Heron (Egretta tricolor) (Sykes, 1987). Also, individuals may roost with other species, especially anhingas (U.S. Fish and Wildlife Service, 1999) and herons (Sykes, 1985). However, aggressive interspecific behavior is very common, most noticeably around an active nest (Stieglitz et al., 1967; Sykes, 1987).
Predation of nests is frequent. Other birds, snakes, and raccoons commonly prey upon eggs or chicks. In Florida, rat snakes (Elaphe obsoleta) are abundant in the marshes the Snail Kite inhabits, and so are considered to be one of their major nest predators (Sykes, 1987; Bennetts et al., 1988). On the other hand, adults do not have natural predators because they occupy a high trophic level, as do most other accipiters.