| dc.description.abstract | The avian family Rallidae is one of the most widespread avian families of the world. Rallidae greatly exceeds the other families within the order Gruiformes in sheer number of species, taxonomic complexity, geographical distribution, and ecological niche. At the time of this writing, there is no comprehensive, readily accessible, and up-to-date compilation of the conservation status of the world's rallids. This thesis provides a brief global overview of the status of rallids worldwide, focusing primarily on regional endemics and threatened species, and identifies the main threats and the associated particular knowledge gaps. The International Union for the Conservation of Nature (IUCN) Red List has a vast database of plants and animals found worldwide. The Red List Index (RLI) measures trends in regards to the risk of extinction; the data available for Rallidae species provides a broad measure of the overall population trend for some of the more cooperative, readily accessible, or targeted species. For many rallids, this is the only current trend indicator available on a regional or global basis. Data of avian families of similar size, equivalent global distributions, and similar lifestyles were also obtained from the RLI to compare for conservation status and population trends to place the circumstances of rallids in context; the families chosen were Anatidae, Cuculidae, Alcedinidae, and Corvidae. A chi-squared test showed significant (p<0.05) differences when comparing Rallidae population trends and conservation status to these four families. Listed threats to Rallidae were obtained from the IUCN and literature searches for the family and species listed as threatened. A chi-squared test showed a significant (p<0.05) number of insular species to have a threatened conservation status when compared to widespread species. Further focus was primarily on endemic and near-endemic species due to the inherent risk to these species as a result of their life history. Invasive species and habitat degradation or destruction were the primary threats identified. Wetland conservation is of special concern, as the majority of Rallidae species utilize this habitat. Internationally designated Important Bird Areas, Endemic Bird Areas, and associated sites designated under the Ramsar Convention were searched for mentions of rallids. In conclusion, Rallidae species are understudied and vast gaps in knowledge exist, particularly for species in remote locations and developing countries. The majority of rallids classified as Least Concern have decreasing or unknown population trends and should be reclassified as Data Deficient until more research is undertaken. The eradication of invasive species, particularly of mammalian predators, is essential to many endemic and near-endemic species recoveries. Habitat protections headed by BirdLife International and the Ramsar Convention are making headway worldwide, and with further research and environmental action the future of Rallidae is in turn better understood and protected. | |
