Snail Kite Rostrhamus sociabilis

  • Order: Accipitriformes
  • Family: Accipitridae
  • Polytypic: 3 subspecies
  • Authors needed...
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Conservation

Conservation Status

Although Rostrhamus sociabilis is classified as Least Concern by the IUCN red list due to its large distribution and global population increases (BirdLife International, 2012), it is a species with a very specialized niche in terms of its habitat and diet (Beissinger et al., 1994; Bergmann et al., 2013) and thus population responses to changes in weather (Reichert et al., 2012) and habitat (Bowling et al., 2012) have been thoroughly studied. Since 1967, when a survey of the Florida population could only find 21 individuals (Stieglitz et al., 1967), there has been concern about Snail Kite populations. Some have highlighted that dispersal of juveniles has accounted for supposed population declines (Rodgers et al., 1988), but it is evident that reproduction and survival of populations is specially sensitive to changes in the hydrology of their environment because it affects the number of breeding attempts (Reichert et al., 2012), the structural stability of nests (Snyder, 1989), predation pressures on nests (Beissinger, 1986), and the ability of finding prey (Bergmann, 2013). In addition, despite the ability juveniles have to disperse when habitat conditions are not optimal, this behavior is also linked to an increased mortality (Bowling et al., 2012).

Currently the Florida population, consisting solely of R. s. plumbeus, is protected by the Florida Everglades National Park but it is still classified as federally endangered in the United States (USFWS, 2013). More research on the status of other populations is needed in order to determine their conservation status.

Effects of human activity on populations

The principal human threat to snail kite populations is due to habitat loss. The marshes and bodies of freshwater snail kites depend on are frequently dried for agriculture or urban areas (USFWS, 2013). Water is used for irrigation and thus water flow is indiscriminately altered. Even worse, in other cases large expanses are totally dried out. Marshes such as the Everglades have been reduced to half of their original size (Davis et al., 1994). This results in the unviability of apple snail populations, which in turn makes snail kite populations abruptly decline.


If habitat is not completely destroyed, some territories have been altered by human activity. For example, pollutants that reach bodies of water from agricultural or urban centers deteriorate water quality and produce eutrophic blooms of vegetation. Dense vegetation covering the water makes hunting more difficult for snail kites because visibility is reduced. For example, in lake Okeechobee contaminants such as phosphorous have been reported to increase in concentration dramatically, raising a general concern of the ability of this habitat to sustain snail kite populations (Janus et al., 1990).

Also, hunters that shoot snail kites may also pose a threat (Stieglitz et al., 1967; Sykes, 1978).

Recommended Citation

Snail Kite (Rostrhamus sociabilis), In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. retrieved from Neotropical Birds Online: https://neotropical.birds.cornell.edu/Species-Account/nb/species/snakit