COSEWIC Assessment and Update Status Report on the King Rail Rallus elegans in Canada ENDANGERED 2000 COSEWIC COSEPAC COMMITTEE ON THE STATUS OF COMITÉ SUR LA SITUATION DES ENDANGERED WILDLIFE ESPÈCES EN PÉRIL IN CANADA AU CANADA COSEWIC status reports are working documents used in assigning the status of wildlife species suspected of being at risk. This report may be cited as follows: Please note: Persons wishing to cite data in the report should refer to the report (and cite the author(s)); persons wishing to cite the COSEWIC status will refer to the assessment (and cite COSEWIC). A production note will be provided if additional information on the status report history is required. COSEWIC 2000. COSEWIC assessment and update status report on the King Rail Rallus elegans in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vii + 10 pp. (www.sararegistry.gc.ca/status/status_e.cfm) James, R.D. 2000. Update COSEWIC status report on the King Rail Rallus elegans in Canada, in COSEWIC assessment and update status report on the King Rail Rallus elegans in Canada Committee on the Status of Endangered Wildlife in Canada. Ottawa. 1-10 pp. Previous Report: Page, A.M. 1994. Update COSEWIC status report on the King Rail Rallus elegans in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 24 pp. Cosens, S.E. 1985. COSEWIC status report on the King Rail Rallus elegans in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 64 pp. For additional copies contact: COSEWIC Secretariat c/o Canadian Wildlife Service Environment Canada Ottawa, ON K1A 0H3 Tel.: (819) 997-4991 / (819) 953-3215 Fax: (819) 994-3684 E-mail: COSEWIC/[email protected] http://www.cosewic.gc.ca Également disponible en français sous le titre Rapport du COSEPAC sur la situation du Râle élégant (Rallus elegans) au Canada – Mise à jour Cover illustration: King Rail — illustration by Ross D. James. Minister of Public Works and Government Services Canada 2002 Catalogue No. CW69-14/3-2002E-IN ISBN 0-662-32601-6 Recycled paper COSEWIC Assessment Summary Assessment Summary – November 2000 Common name King Rail Scientific name Rallus elegans Status Endangered Reason for designation The population of this species in Canada is very small and shows continued decline. Few patches of remaining habitat are large enough and of sufficient quality to support this species. It is also considered endangered or critically imperiled in all adjacent states. Occurrence Ontario Status history Designated Special Concern in April 1985. Status re-examined and designated Endangered in April 1994. Status re- examined and confirmed in November 2000. Last assessment based on an updated status report. iii COSEWIC Executive Summary King Rail Rallus elegans Description The King Rail is a compact bird with a short tail, and short rounded wings. The legs are moderately long, and the beak is long and slightly decurved. The body is laterally compressed to help in moving through marsh vegetation where it lives. Males and females are similar with slate coloured crown and back, the latter with prominent tawny edges to the feathers, a white throat and buffy eye stripe, and chestnut underparts, with heavily barred black and white sides. It is a large rail about 38 cm long, much larger than the very similar Virginia Rail. The call is a series of up to 10 kek kek kek notes fairly evenly spaced. Juveniles are similar to adults, but darker above and duller brown below. Distribution It ranges over most of the eastern United States, except in the higher Allegheny Mountain areas. It also occurs along the Gulf coast of Mexico, although not into the Yucatan Peninsula, and on Cuba. However, in the United States now it is not common except close to the Gulf and Atlantic coasts, and in the lower Mississippi Valley. It breeds in Canada only in extreme southern Ontario. It is a migratory species, with any birds in the interior of the continent moving to the coasts. Most winter in the U.S. states along the Gulf coast and the Atlantic coast of the summer range. Population size and trend In the past 30 years the King Rail has experienced severe declines through most of its range. In the U.S., it was formerly common in the Lake Erie marshes of Ohio, and in the Lake St. Clair area of Michigan, but no longer is. It is now considered critically imperiled in all adjacent U.S. states. Apart from Louisiana and Florida it may be considered at least threatened. It was formerly common at least in the Lake St. Clair area of Ontario, and probably in all large marshes in the Lake Erie area. They may also have occurred in larger Lake Ontario marshes. But, by the mid-1980s there were estimated to be fewer than 300 pairs, and that estimate was based largely on the area of large marshes that might have suitable habitat. iv By 1990, more extensive surveys suggested that there were fewer than 50 pairs, almost all concentrated in the Lake St. Clair marshes. A few pairs could still be found in four or five other Lake Erie marshes, but numbers varied and presence was irregular. A few scattered records came from as far north as the Bruce Peninsula and Lake Simcoe, and east to Presqu’ile Provincial Park, but such birds may not find mates, or return in subsequent years. Specific surveys for King Rail in 1997, 1998, and 1999 have confirmed that the population is still fewer than 50 pairs, mainly in the Walpole Island marshes. Habitat It occupies a wide variety of freshwater marshes in the breeding season. In many areas the presence of wild rice seems to be important for food, but sedge and cattail marshes and shrub swamp habitats are also used. Very large marshes, with more open water areas merging with shrubby areas are probably essential habitat in Canada. Minimum size requirements are unknown, but only in the largest marshes does it persist. It is thought that only about 10% of the original available marsh remains in the Lake St. Clair area where the largest component of the population persists. The other large marshes are isolated, making it more difficult for individual birds to find mates. General biology Birds return to Ontario by early May and males call to attract a mate. The male apparently engages in courtship feeding, but little is known of their behaviour, because of the secretive nature of the birds. They are more easily heard than seen. The size of the territory occupied can vary considerably depending upon quality, but no information is available from Ontario. Nests are placed in clumps of grasses and sedges that cover over the nest. Dead marsh vegetation is used to form a shallow cup into which about 8 to 11 eggs are laid, sometimes one to three more. Eggs are laid in late June or early July, usually one per day. The incubation period is about 21 days, with both sexes assisting. Young birds are capable of leaving the nest and following their parents shortly after hatching. But, they are fed by parents almost exclusively for several days and to a large extent for at least 3 weeks. Young stay with parents and are fed to some extent for about 6 weeks. After that they may remain with adults for some time although feeding themselves. Usually only one brood is raised per season because of the long period of dependency by the young. Hatching success is high, but only about 50% of young survive the first two weeks. Foxes, raccoons, crows, hawks, and owls of various types will take eggs and young birds, as well as adults. Diet consists of a variety of aquatic insects and crustaceans. Crayfish, frogs, fish, grasshoppers, crickets, small clams, and beetles form the largest part of the diet. Indigestible parts are ejected in pellets. Seeds of plants are also eaten, especially wild rice. v Because of its secretive nature, it is seldom seen, and little known by many people. It has been classified as a game bird throughout its range. Apparently few are taken anymore, even in the southern U.S., and in Canada it has probably not been hunted for years. Rail hunting is not popular in Canada, and the rarity of the species would eliminate it as a potential target. Limiting factors Loss of wetland habitat has been the greatest single factor in the decline of the King Rail in Ontario, and is the greatest threat to their continued existence. There may be fewer threats to large marshes in recent years, but there are still local incremental losses, disturbances, and degradation through sedimentation and runoff of pesticides, herbicides, and chemical fertilizers. Toxins may either reduce the available food, or indirectly poison the birds. Burning of parts of the remaining marsh habitat each year may delay breeding and thus reduce productivity, or render some habitat unuseable. The effects are unknown. The invasion of marshes by introduced plants such as phragmites or loosestrife can seriously change the character of the marsh and render it unsuitable. The presence of carp can also significantly reduce invertebrate prey for a number of wetland birds including rails. Water depths in managed marshes may not provide the right requirements. Fluctuations in water levels that occur naturally rejuvenate marshes periodically, but this may not happen in managed marshes. Dikes interfere with the shoreline structure. King Rails prefer wet to dry situations and will be vulnerable to shoreline alterations that reduce the availability of adjacent wet meadows and upland habitat. Predators like raccoons, crows, coyotes and foxes proliferate in human-dominated landscapes, and greatly increase mortality in marshes.