King Rail Research Articles

Predicting the Spatial Distribution of King Rails in an Agricultural Landscape

Species distribution modeling is valuable for assessing rare or elusive species and in landscapes where accessibility is limited, such as agricultural lands. While birds' local habitat associations are often well known, knowledge of broad-scale relationships and the spatial patterns of environmental factors is generally lacking. In this study, we develop and validate a predictive habitat model for the King Rail (Rallus elegans) in the rice-growing region of southwestern Louisiana and identify important areas for this elusive bird. In a previous localized study we found it to be associated with canopy cover and ditches/streams around the perimeter of rice fields. Here, we used a geographic information system (GIS) to extrapolate these habitat associations to the region (>940 000 ha). We determined the proportion of rice fields within a 5-km radius and quantified canopy cover and ditches within a 1-km radius. In repeated call-back surveys from 2007 to 2009 we recorded King Rails at 44 of 155 locations. On this basis, accounting for imperfect detection, we modeled King Rail occurrence. The validation results showed the model had good predictive ability, and in 17% of the area the predicted probability of occurrence was high. Accounting for imperfect detection resulted in an increased probability of occurrence. Most importantly, the spatial pattern revealed the threat of encroaching woody vegetation and the vulnerability of rail habitat to hurricanes and further land-use changes. Our study illustrates that field research can be extrapolated to GIS-based spatial models, which can identify key spatial patterns in a species' distribution.

Population Status and Habitat Associations of the King Rail in the Midwestern United States

The migratory population of the King Rail (Rallus elegans) has declined dramatically during the past 50 years, emphasizing the need to document the distribution and status of this species to help guide conservation efforts. In an effort to guide King Rail breeding habitat protection and restoration, a landscape suitability index (LSI) model was developed for the Upper Mississippi River and Great Lakes Region Joint Venture (JV). To validate this model, 264 sites were surveyed across the JV region in 2008 and 2009 using the National Marshbird Monitoring protocol. Two other similarly collected data sets from Wisconsin (250 sites) and Ohio (259 sites) as well as data from the Cornell Laboratory of Ornithology's eBird database were added to our data set. Sampling effort was not uniform across the study area. King Rails were detected at 29 sites with the greatest concentration in southeastern Wisconsin and northeastern Illinois. Too few detections were made to validate the LSI model. King Rail detection sites tended to have microtopographic heterogeneity, more emergent herbaceous wetland vegetation and less woody vegetation. The migrant population of the King Rail is rare and warrants additional conservation efforts to achieve stated conservation population targets.

Distribution and Habitat Associations of Breeding Secretive Marsh Birds in Louisiana’s Mississippi Alluvial Valley

Populations of many North American secretive marsh birds (SMBs) have declined in recent decades, partially as a function of wetland loss. Protecting and restoring appropriate habitat for these species is contingent upon understanding the habitat features they utilize. We investigated breeding distributions of SMBs in northeast Louisiana at 118 wetlands in 2007 and 2008 and modeled species occupancy (ψ) as a function of habitat variables measured at local (≤100 m) and landscape (≤1 km) scales. Common Moorhens (Gallinula chloropus), Least Bitterns (Ixobrychus exilis), and Purple Gallinules (Porphyrula martinica) were the most commonly detected species, whereas breeding King Rails (Rallus elegans) and American Coots (Fulica americana) were rare. Local habitat features consistently played a greater role in predicting ψ than landscape features for the three most common species. The proportion of local wetland area dominated by robust emergent vegetation (i.e., Typha spp. and Zizaniopsis miliacea) positively influenced ψ for all species, while other wetland vegetation types tended to have a minimal or negative effect. Our results suggest the habitat characteristics preferred by breeding SMBs differ from those used by migrating shorebirds and wintering waterfowl and management and restoration objectives for those species may be inadequate for enhancing SMB habitat.

Habitat Use of Nesting and Brood-rearing King Rails in the Illinois and Upper Mississippi River Valleys

Most studies of King Rail (Rallus elegans) have investigated habitat use during the nesting season, while few comparisons have been made between the nesting and brood-rearing seasons. King Rails were located during the nesting season in Missouri using repeated surveys with call playback, and systematic searches for broods were conducted during the brood-rearing season. King Rail adults were located at twelve points in 2006 and 14 points in 2007, and five King Rail broods were located in each year. Water depth was measured and dominant cover type determined for randomly sampled 5-m plots within used and unused habitats. Logistic regression models were fitted to the data and top models were selected from the candidate set using AICc. Nesting adults occurred more often in areas dominated by short (≤1 m) emergent vegetation ( = 0.77 ± 0.27) and deeper water ( = 0.05 ± 0.02). Broods occurred more often in areas dominated by short emergent vegetation ( = 1.19 ± 0.37) and shallow water ( = -0.17 ± 0.06), and avoided areas dominated by tall (>1 m) emergent vegetation ( =-1.15 ± 0.45). A modified catch-curve analysis was used to estimate chick daily survival rates during selected 7-day periods for each year. Daily survival rate ranged from 0.92 ± 0.008 in late June 2007 to 0.96 ± 0.005 in late July 2006. Management plans for King Rails should include the different habitat types needed during the nesting and brood-rearing stages.

Status and Distribution of Breeding Secretive Marshbirds in the Delta of Arkansas

We surveyed the Lower Mississippi Alluvial Valley of Arkansas (“the Delta”) during the breeding seasons of 2005 and 2006 using the national marshbird monitoring protocol for secretive marshbirds. We detected and documented breeding by Podilymbus podiceps (Pied-billed Grebe), Ixobrychus exilis (Least Bittern), Rallus elegans (King Rail), and Gallinula chloropus (Common Moorhen). We detected but did not document breeding by Botaurus lentiginosus (American Bittern), Porphyrula martinica (Purple Gallinule), and Fulica americana (American Coot), all of which have been documented to breed in the Delta. Our estimated occupancy rates for breeding marshbirds in the study area ranged from a low of 6% for the King Rail in 2006 to a high of 27% for the Least Bittern in 2005. The range of these occupancy rates are low and reflect the rarity of secretive marshbirds in the Delta. Secretive marshbird occupancy rates were higher in the southern third of the Delta, probably because wetlands were more abundant or of higher quality there.

Effectiveness of Capture Techniques for Rails in Emergent Marsh and Agricultural Wetlands

A reliable and effective technique for capturing rails would improve researchers' ability to study these secretive marsh birds. The time effectiveness and capture success of four methods for capturing rails in emergent marsh and agricultural wetlands in southern Louisiana and Texas were evaluated during winter and breeding seasons. Methods were hand and net capture from an airboat at night, an all-terrain vehicle (ATV) at night, an ATV during daylight rice harvest and passive capture using drop-door traps with drift fencing. Five hundred and twenty rails were captured (and 21 recaptures): 192 King Rails (Rallus elegans), 74 Clapper Rails (R. longirostris), 110 Virginia Rails (R. limicola), 125 Sora (Porzana Carolina) and 40 Yellow Rails (Coturnicops noveboracensis). Methods used at night were effective at capturing rails: capture from airboats yielded 2.13 rails per hour each airboat was operated and capture from ATVs yielded 1.80 rails per hour each ATV was operated. During daylight, captures from ATVs during rice harvest (0.25 rails per hour each ATV was operated) and passive drop-door traps with drift fencing (0.0054 rails per trap hour) were both inefficient.

Distribution and Habitat Use of King Rails in the Illinois and Upper Mississippi River Valleys

ABSTRACT The migratory population of the king rail (Rallus elegans) has declined dramatically during the past 40 years, emphasizing the need to identify habitat requirements of this species to help guide conservation efforts. To assess distribution and habitat use of king rails along the Illinois and Upper Mississippi valleys, USA, we conducted repeated call‐broadcast surveys at 83 locations in 2006 and 114 locations in 2007 distributed among 21 study sites. We detected king rails at 12 survey locations in 2006 and 14 locations in 2007, illustrating the limited distribution of king rails in this region. We found king rails concentrated at Clarence Cannon National Wildlife Refuge, an adjacent private Wetlands Reserve program site, and B. K. Leach Conservation Area, which were located in the Mississippi River floodplain in northeast Missouri. Using Program PRESENCE, we estimated detection probabilities and built models to identify habitat covariates that were important in king rail site occupancy. Habitat covariates included percentage of cover by tall (>1 m) and short (>1 m) emergent vegetation, percentage of cover of woody vegetation, and interspersion of water and vegetation (2007 only) within 50 m of the survey location. Detection probability was 0.43 (SE = 0.12) in 2006 and 0.35 (SE = 0.03) in 2007 and was influenced by observer identity and percentage of cover by tall herbaceous vegetation. Site occupancy was 0.11 (SE = 0.04) in 2006 and 0.14 (SE = 0.04) in 2007 and was negatively influenced most by percentage of cover by woody vegetation. In addition, we found that interspersion of vegetation and water was positively related to occupancy in 2007. Thus, nesting king rails used wetlands that were characterized by high water‐vegetation interspersion and little or no cover by woody vegetation. Our results suggest that biologists can improve king rail habitat by implementing management techniques that reduce woody cover and increase vegetation‐water interspersion in wetlands.

Effectiveness of Call-Broadcast Surveys for Breeding Marsh Birds Along Coastal Alabama

Point-count surveys targeting Ixobrychus exilis (Least Bittern), Laterallus jamaicensis (Black Rail), Rallus longirostris (Clapper Rail), Rallus elegans (King Rail), Porphyrio martinica (Purple Gallinule), and Gallinula chloropus (Common Moorhen) were performed using a standardized marsh-bird monitoring protocol along tidally influenced emergent marshes of coastal Alabama during the 2004 breeding season. We compared the number of target species detected during an initial passive-listening period to those detected during a subsequent multiple-species call-broadcast period to evaluate the effectiveness of the call-broadcast period for increasing detections. Additionally, we examined the number of responses of each target species to conspecific and heterospecific calls to determine how marsh birds respond to multiple species call-broadcast sequences. Numbers of new individuals detected during call-broadcast periods were significantly greater (P < 0.05) than those detected during the initial passive-listening period for Clapper Rail, King Rail, and Purple Gallinule, but not for Least Bittern and Common Moorhen. Black Rails were not detected during this study. Conspecific calls were more effective at eliciting responses than heterospecific calls for each of the target species except Least Bittern. Although the calls of Clapper Rail and King Rail are very similar, our data indicate that the advertisement calls of both species should be incorporated within multiple species call-broadcast sequences where populations are sympatric. We also recommend that Purple Gallinule call-broadcasts be applied to marsh-bird inventories or monitoring programs throughout this species' range as a result of its effectiveness, which was previously uncertain.

Use of Morphometric Measurements to Differentiate between Species and Sex of King and Clapper Rails

King Rails (Rallus elegans) and Clapper Rails (Rallus longirostris) are large, secretive waterbirds whose ranges overlap in brackish marshes along the Atlantic and Gulf Coasts. King and Clapper Rails are difficult to separate by physical appearance and there is currently no reliable method to distinguish between the two species. Here, the relative effectiveness of using discriminant analysis of morphometric measurements to identify and sex King and Clapper Rails was examined. Mean measurements of wing, tarsus, and weight were different between male King and Clapper Rails and between female King and Clapper Rails. However, for all measurements except culmen, male Clapper Rails and female King Rails were not different. Discriminate analysis of morphometric measurements revealed that wing, tarsus, and culmen measurements differentiated between King and Clapper Rails, but cross-validation results for male Clapper Rails were only 73%. Male King Rails were larger than female King Rails for all morphometric measurements and male Clapper Rails were larger than female Clapper Rails for all morphometric measurements except for the tail. Wing and tarsus measurements differentiated between male and female King Rails and wing, tarsus, and culmen measurements differentiated between male and female Clapper Rails.

Relative Nest Density, Nest Success, and Site Occupancy of King Rails in Southwestern Louisiana Rice Fields

Abstract King Rail (Rallus elegans) populations are listed as threatened or endangered in 13 states. One remaining area of relative abundance is the rice-growing region of southwestern Louisiana. Rice fields are flooded for much of the year and support thick emergent vegetation, potentially providing high-quality habitat for King Rails. The objectives of this study were to determine: 1) relative nest density of King Rails in rice; 2) which local and landscape factors influence relative nest densities; 3) nest survival of King Rails in rice fields; 4) effectiveness of callback surveys in indicating King Rail breeding activity; and 5) site occupancy of King Rails in rice fields. In the summers of 2004 and 2005, King Rail surveys and nest searches were conducted in Cameron, Jefferson Davis, Vermilion, and Acadia Parishes in southwestern Louisiana. In 2004, 42 fields were searched for nests and 30 of those were surveyed with callback survey techniques. In 2005, 40 fields were searched and 60 were surveyed. A ...

SPECIES OCCURRENCE OF MARSH BIRDS AT CAPE COD NATIONAL SEASHORE, MASSACHUSETTS

We initiated an inventory and a field test of a protocol that could be used for monitoring marsh birds at the Cape Cod National Seashore in eastern Massachusetts during 1999 and 2000, as part of a more comprehensive national effort. Using cassette tapes during call broadcast surveys, we visited a total of 78 survey points at freshwater, brackish, and salt marsh sites three times on the ground or in canoes during the breeding season (May–June), fall migration (September to November), and twice during winter (December–January). Observer bias on our marsh bird surveys appeared negligible. Although both auditory and visual detection of most species was low (mean < 0.3 birds per replicate-survey point), we confirmed the presence of seven marsh species, including American Bittern (Botaurus lentiginosus), Least Bittern (Ixobrychus exilis), American Coot (Fulica americana), King Rail (Rallus elegans), Pied-billed Grebe (Podilymbus podiceps), Sora (Porzana carolina), and Virginia Rail (Rallus limicola). We suspected breeding of Least Bitterns and Soras at Great Pond in Provincetown, and for Virginia Rails at Hatches Harbor, Provincetown. The most frequently detected species were Soras, Pied-billed Grebes, and Virginia Rails. We recommend using call broadcast surveys for these cryptic species to enhance their probabilities of detection.

Molecular Genetic Divergence between Avian Sibling Species: King and Clapper Rails, Long-Billed and Short-Billed Dowitchers, Boat-Tailed and Great-Tailed Grackles, and Tufted and Black-Crested Titmice

Abstract Surveys of electrophoretic variation in proteins, and restriction site variation in mitochondrial DNA (mtDNA), were conducted to assess the resolving power of these molecular genetic techniques to distinguish four pairs of avian sibling taxa. Samples of rails (Rallus elegans and R. longirostris), dowitchers (Limnodromus scolopaceus and L. griseus), grackles (Quiscalus major and Q. mexicanus), and titmice (Parus bicolor bicolor and P. b. atricristatus) were assayed for allozymes encoded by 34-37 nuclear loci, and for an average of 77 mtDNA restriction sites per individual by 19 endonucleases. MtDNA's of the two rail species showed large-scale size polymorphism and individual heteroplasmy, the first such findings of these molecular features in an avian species. Genetic distances based on allozyme comparisons were small for all assayed taxa (Nei's D ≤ 0.063). The mtDNA assays offered consistently greater resolving power, providing at least five fixed restriction site differences for samples of any taxon pair. The Long-billed and Short-billed dowitchers were especially divergent, differing by at least 24 assayed mtDNA restriction sites and an estimated nucleotide sequence divergence of p = 0.082. We compared these results to previous reports of genetic distances within and among closely related bird species. The mtDNA divergence among dowitchers is near the high end of the scale of such estimates for avian congeners. The mtDNA distances between the pairs of rails (p = 0.006), titmice (p = 0.004), and grackles (p = 0.016) were typical for extremely closely related species, and overlap maximum values reported for some avian conspecifics.

Extra-renal salt excretion in clapper and king rails

1. 1. The concentration and volume of salt gland secretion (SGS) were measured in newly captured, freshwater (FW) and sea-water (SW) acclimated clapper rails (permanent salt marsh species) and king rails (wintering salt marsh species), orally loaded with 10% NaCl (10 ml/kg). 2. 2. Newly captured clapper rails produced SGS at a higher rate and concentration than newly captured king rails. Maintaining clapper rails on SW did not affect SGS rate or concentration, but raised king rail SGS to clapper rail levels. After acclimation to FW, the SGS concentration decreased by about 10%, flow rate decreased by about 35% and extra-renal Cl excretion decreased 30–40% in both species. 3. 3. Following SW acclimation, both rail species produced SGS of a concentration characteristic of more marine species, such as the gull, but the SGS flow rate was much slower, so that rail chloride excretion (mg/min) was about 10% that of a gull.

Observations on the Food and Food Habits of Clapper Rails (Rallus longirostris Boddaert) from Tidal Marshes Along the East and Gulf Coasts of the United States

The feeding habits of five nominal subspecies of clapper rails (Rallus longirostris Boddaert) collected in tidal marshes along the Gulf and Atlantic coasts of the United States are compared. Data on the food from the stomachs of 183 rails were analyzed and the earlier literature critically reviewed. During the warmer months (May through early fall), crabs, predominantly Uca spp., comprised the major part of the food items found. Limited data on a few rails collected during late fall and winter, when Uca spp. are not usually available, indicate that snails then become a major part of the clapper rail’s diet during that part of the year. Earlier studies, which describe the food or feeding habits of clapper rails, are reviewed and the food habits and trophic relationships of some other tidal marsh consumers are discussed. Data from this and previous studies indicate that clapper rails are opportunistic omnivores, and occupy a relatively broad niche within tidal marsh ecosystems. A comparison of available data of the food of five clapper rail subspecies of the eastern United States indicates no distinct differences in their feeding behavior. Differences in the kinds of food eaten appear to simply reflect the types of marsh habitat (fresh, brackish, polyhaline) or geographical location (temperate, subtropical, tropical) in which a particular clapper rail population occurs. The food habits of the king rail are compared with those of the clapper rail and problems concerning the taxonomic status of the “subspecies” of Rallus longirostris are briefly discussed.

The Pleistocene Rails of North America

Wetmore (1931) assigned two fragments of tarsi and a femur from Pleistocene deposits excavated at Seminole Field, Pinellas County, Florida, to the Gray-necked Wood Rail, Aramides cajanea. This species is presently distributed from southern M6xico to Argentina. In view of the Neotropical flavor of much of the Pleistocene fauna of Florida, it was not a wholly unexpected discovery but, unfortunately, the record is based on incorrectly identified material. On restudying the specimens involved (USNM 12192), I found that none pertains to Aramides. The femur is from a small individual (probably a male) of Redshouldered Hawk, Buteo lineatus. The distal right tarsus and proximal right tarsus are from different individuals and are rallid; however, both are from the King Rail, Rallus elegans. Both Buteo lineatus and Rallus elegans were recorded by Wetmore from the Seminole Field site. The tarsi of Aramides and Rallus are quite distinct in their entirety but in the fragmentary condition of the fossils are less easily separated. In the distal fragment, the distal foramen in posterior view is oval and placed higher than in Aramides cajanea, in which the distal foramen is round. The middle trochlea is not as heavy and expanded distally as in A. cajanea, but the scar for the hallux is deeper. In external view, the shaft extending to trochlea 4 is wide and heavy, unlike A. cajanea in which this shaft is narrow and flattened; also, the groove in trochlea 4 does not extend through most of the anterior face of the trochlea as it does in Aramides. In anterior view, the outer extensor groove is longer and deeper than in Aramides. In all these respects, the fossil agrees with Rallus elegans. In the proximal tarsal fragment, in anterior view the intercotylar prominence is lower and flatter than in Aramides; the hypotarsus is not as deeply excavated on the internal face and in internal view the ridge from the internal cotyla is broader and not as sharply marked off from the hypotarsal area as it is in A. cajanea. In these respects this specimen, too, agrees with Rallus elegans. Aramides cajanea must therefore be removed from the fossil record of North America.

King Rail and Flammulated Owl at El Paso, Texas

King Rail and Flammulated Owl at El Paso, Texas

The Nasal Mites of Birds from Louisiana. I. Dermanyssids (Rhinonyssinae) from Shore and Marsh Birds

New species, host records, and geographic records of nasal mites of several rhinonyssine genera (Dermanyssidae) are reported from aquatic and semiaquatic birds in Louisiana. Two new species, Rhinonyssus podilymbi from Podilymbus podiceps and Tinaminyssus neoixobrychi from Ixobrychus exilis, are described. New host records are established for Rhinonyssus rhinolethrum from Aix sponsa and Fulica americana, Rallinyssus verheyeni from Rallus elegans and R. limicola, Larinyssus orbicularis from Sterna hirundo, and Tinaminyssus belopolskii from Florida caerulea, Butorides virescens, and Leucophoyx thula. New geographic records are established for these mites as well as Rhinonyssus coniventris, R. himantopus, R. strandtmanni, Rallinyssus caudistigmus, and Tinaminyssus bubulci. The systematics, affinities, and host relationships of these genera and species are discussed. Nasal mites of North American birds have been the subject of numerous investigations (Brooks and Strandtmann, 1960; Clark, 1958, 1963, 1964; Fain and Hyland, 1963; Fain and Johnston, 1966; Furman, 1957; George, 1961; Hyland, 1961a, b, 1962; Hyland and Clark, 1959; Strandtmann, 1948, 1951, 1952, 1956a, b, 1958, 1959, 1961, 1962; Strandtmann and Clifford, 1962; Strandtmann and Furman, 1956; Strandtmann and Wharton, 1958). However, there have been no published accounts of an intensive survey for these acarids in any region of this continent. In the present study, an effort was made to determine, as far as possible, the occurrence of mites of the families Dermanyssidae (Rhinonyssinae), Ereynetidae, and Epidermoptidae from the nasal passages of birds in Louisiana. This paper is concerned with the Rhinonyssinae, exclusive of the genus Sternostoma, from aquatic and semiaquatic birds. MATERIALS AND METHODS All birds were collected within a radius of 150 miles of New Orleans, Louisiana. Hosts were examined for nasal mites as quickly as possible after death according to the methods outlined by Fain (1956). Nasal mites were fixed alive in hot (70 to 80 C) 80% ethyl alcohol. This usually provided good extension of the legs and extrusion of the chelicera. Exfoliation of the cuticle or rupture of the specimens sometimes occurred when they were fixed at temperatures above 80 C. Specimens were stored in 80% ethyl alcohol at least a week. Mites were mounted directly from alcohol into Hoyer's medium on glass slides and Received for publication 5 August 1971. covered with 12-mm no. 0 cover slips. Some heavily sclerotized forms (Larinyssus, Rallinyssus) were cleared in warm lactic acid a few minutes prior to mounting. This procedure was avoided when possible since it often resulted in rupture of the specimens. Slides were placed in a drying oven at 40 C at least a week prior to ringing with 2 coats of fingernail polish and a final coat of Glyptol (G. C. Electronics, Rockford, Ill.). Specimens were examined with a compound light and phase contrast microscopes. Figures were made with the aid of a camera lucida. All measurements are in microns unless otherwise indicated. Designations used in the following descriptions are as follows and are taken largely from Fain and Hyland (1962a).

Natural History of the King Rail

Natural History of the King Rail

NATURAL HISTORY OF THE KING RAIL

Summary of the king rail, including history, distribution and migration, physical description, breeding biology, foods, feeding behavior, mortality factors, and status as a game bird.

Ecological Notes on Mixed Populations of King Rails and Clapper Rails in Delaware bay Marshes

Ecological Notes on Mixed Populations of King Rails and Clapper Rails in Delaware bay Marshes