AUTHORS: Nate Engbrecht, Indiana Department of Natural Resources, Division of Fish & Wildlife
ABSTRACT: The Crawfish Frog (Lithobates areolatus) is a fossorial, prairie-dwelling species of the central United States that has declined across several parts of its geographic range. Populations east of the Mississippi River have been especially impacted and it was recently designated as a Regional Species of Greatest Conservation Need. Crawfish Frogs are "obligate crayfish burrow dwellers" that spend much of their lives in close association with their primary burrow, often returning to the same burrow following annual breeding migrations in excess of 1 km. The loss of grasslands, wetlands, and impacts to burrows through soil disturbance poses a triple threat to the frog's conservation status. Despite these challenges, Crawfish Frogs have shown a remarkable ability to colonize new areas once suitable habitat is made available, including reclaimed coal mines and military munition testing sites. Emerging data indicate that egg mass translocation may be effective tool for starting new populations at remote or isolated localities. This report provides an overview of Crawfish Frog life history, habitat use, and conservation implications across the species’ Midwestern range.
AUTHORS: J. Daren Riedle Kansas Department of Wildlife and Parks, Ecological Services Section, Pratt, KS, USA.
ABSTRACT: The Crawfish Frog, Lithobates areolatus, has been known from Kansas since the early 1900’s. They are thought to be locally common in remnant tallgrass prairie, although its relatively brief breeding season and secretive habit of remaining in burrows creates the perception of rarity. The distribution of the species in Kansas appears to range along the eastern edge of the Flint Hills eastward to the Missouri border and south in Oklahoma. The Crawfish Frog was originally listed as Threatened under the Kansas Nongame and Endangered Species Conservation Act of 1975 but was down-listed to a Species In Need of Conservation in 1993. While no systematic surveys have been completed for the species, it is thought that the distribution has changed little, although some evidence has suggested some population declines.
AUTHORS: Kaleb M. Banks, Oklahoma State University; Owen M. Edwards, Oklahoma Biological Survey; Bo Zhang, Oklahoma State University; Michael S. Reichert, Oklahoma State University
ABSTRACT: Crawfish frogs (Rana areolata) are in decline across much of their range, primarily due to habitat loss and degradation from agricultural practices that disrupt prairie ecosystems and soil structure. These declines are most pronounced east of the Mississippi River, where R. areolata has been extirpated from 59% of its historical counties. In Oklahoma it has been over 70 years since Arthur Bragg's 1953 crawfish frog study, and the contemporary distribution and status of the species is unclear. Since much of eastern Oklahoma is characterized by low-intensity agriculture, such as cattle ranching, we hypothesize that crawfish frogs in the region may be less vulnerable to population declines compared to other states. To investigate this, we conducted comprehensive frog call surveys, deployed acoustic recorders, and performed visual encounter surveys to identify new populations. Additionally, we used species distribution modeling to identify suitable habitat. During the 2022 and 2023 seasons, we conducted 754 frog call surveys, identifying crawfish frog populations at 276 sites. Additionally, acoustic recorders and visual encounters confirmed frogs at 27 more sites, bringing the total to 303. Our surveys verified populations in all 23 counties originally documented by Bragg, along with four new county records. Our species distribution model identified annual rainfall and the percentage of untilled prairie as the most significant variables influencing crawfish frog range. These findings suggest that low-intensity cattle ranching and lack of tilled soil are likely contributing to this species' success in Oklahoma.
AUTHORS: Amanda R. Bryant, Arkansas Game and Fish Commission (Presenting); Chelsea Kross, US Fish and Wildlife Service; Elliot Lassiter, University of Arkansas; Ethan Royal, University of Arkansas; J.D. Wilson, University of Arkansas;
ABSTRACT: Crawfish Frogs historically occurred within all ecoregions of Arkansas with the majority of populations concentrated in tallgrass prairie habitats within the Ozark Highlands and the Arkansas Valley. This species’ need for large areas of prairie and grassland habitat with adjacent suitable breeding wetlands makes them especially vulnerable to habitat alteration and fragmentation. Widespread land use conversion for agriculture and urban development is considered the primary cause of declines in this species, particularly in the Ozark Highlands. In an effort to conserve this species within Northwest Arkansas, two State Wildlife Grant funded projects were recently completed. The first focused on distribution and occupancy and as a result of these efforts, Crawfish Frogs were detected within ten protected areas along with several other detections on private lands. However, no individuals were detected at several previously known populations within the Ozark Highlands. Due to the rapid urbanization and fragmentation of the Ozarks, the most stable populations of this species occur within the Arkansas Valley and around a protected network of smaller prairies preserves as well as Fort Chaffee. The second SWG project focused on terrestrial habitat use in this prairie network to determine if these currently protected areas are sufficiently large to protect remaining populations. This research found that Crawfish Frogs in this area migrate roughly half as far from their breeding wetlands as those in Illinois and Texas and also identified key breeding wetlands on private lands adjacent to currently protected areas. It also identified currently protected areas that would benefit from artificial breeding wetland creation. This research is being used to guide targeted acquisition of these breeding wetlands and to increase our capacity to protect this species and ensure continued health of these populations.
AUTHORS: Jeffrey T. Briggler, Missouri Department of Conservation
ABSTRACT: Crawfish Frogs are a grassland-dependent species that historically occurred throughout former native prairie habitats in northcentral and southwestern Missouri. This decline of this species of conservation concern has been primarily linked to the destruction of upland grasslands where individuals spend most of the year inhabiting crayfish burrows, and the draining of seasonal and semi-permanent wetlands where they breed during late winter and early spring. Overview of their status, distribution, and threats in Missouri will be discussed. In addition, conservation efforts, such as population surveys, land acquisitions and conversions, wetland constructions, and reintroductions will be highlighted. With increased efforts to establish a collaborative network to focus on the recovery of this at-risk grassland species, the snoring call of the Crawfish Frog will continue to be heard for future generations.
AUTHORS: Paul W. Frese, Iowa Department of Natural Resources
ABSTRACT: The Northern Crawfish Frog, Lithobates areolatus, has not been documented in Iowa since 1942 and is classified as endangered in the state. In the last three decades, concerted efforts by multiple researchers have failed to find any sign of the crawfish frog in Iowa and they are almost certainly extirpated. Crawfish frogs have experienced declines throughout their range due to habitat loss or degradation and there is no evidence that crawfish frogs were extirpated from Iowa due to factors other than habitat destruction. Recent research has provided vital information on the natural history and ecology of crawfish frogs as well as habitat suitability assessments of potential release sites giving us tools and knowledge to improve the success rate of a species restoration project. I will review the known historical record of crawfish frogs in Iowa and give an update of the status of potential repatriation efforts in the state.
AUTHORS: Scott Ballard Herpetologist Illinois Department of Natural Resources
ABSTRACT: Crawfish frogs are an Illinois Species of Greatest Conservation Need that historically occurred in roughly the southern one-third of Illinois. Declines can be attributed to the alteration of wetland breeding habitat that affects the water table, hence reducing crayfish occupation and the burrows this species relies on. Overview of the species legal status, distribution, breeding phenology, population status, threats, and conservation efforts will be discussed.
AUTHORS: Nate Engbrecht, Indiana Department of Natural Resources, Division of Fish & Wildlife
ABSTRACT: Crawfish Frogs (Lithobates areolatus) are a state endangered species that have been the subject of considerable research along the eastern edge of their range in Indiana. Contemporary data indicate the species has undergone a range contraction along the northern and eastern periphery of its distribution in the state, and that extant populations tend to be isolated and widely separated by miles of uninhabitable farmland. The species has shown a remarkable ability to colonize restored sites when suitable habitat becomes available and nearby source populations are present; however, a lack of connecting corridors is restricting natural dispersal. To restore Indiana’s Crawfish Frog populations, the Indiana Department of Natural Resources has begun translocating egg masses from a robust population in Greene County to a recovery site along the Ohio River where a historic Crawfish Frog population once existed, before disappearing in the 1980s. This presentation discusses the historic decline of Crawfish Frogs in Indiana, their current conservation status, and the early stages of species recovery through habitat management and human mediated translocation.
AUTHORS: Owen M. Edwards, Oklahoma Biological Survey; Neil R. Balchan, Oklahoma State University; Kaleb M. Banks, Oklahoma State University; Michael S. Reichert, Oklahoma State University; Fabio A. Machado, Oklahoma State University; Bo Zhang, Oklahoma State University; Damien Esquerré, University of Wollongong
ABSTRACT: During the breeding season, male anurans utilize advertisement signals to attract mates. However, in many scenarios, mate signaling and subsequent reproduction can occur in shared bodies of water in which numerous different species congregate and reproduce at the same time. As a result, natural hybridization between closely related species is not uncommon, and can have major consequences on fitness and evolutionary processes. The crawfish frog (Rana areolata) is a secretive anuran that has disjunct distribution in the southern and midwestern United States. Over the last 50 years, there has been a rapid and ongoing population decline of these frogs in many states in their range, largely attributed to habitat loss and landscape changes. We conducted population monitoring using drift fences and pitfall traps in a breeding population of R. areolata in Oklahoma. During the first year of the study, we discovered individual putative R. areolata hybrids at our study pond: one breeding adult resembling R. palustris x R. areolata, and another breeding adult resembling R. sphenocephala x R. areolata. Here, we confirm the status of these hybrid individuals using 1) cranial morphology via microCT scanning and 2) genome-wide single-nucleotide polymorphism (SNP) data. Hybrid skulls represent phenotypic intermediate between parental populations, and preliminary analysis of SNP data indicate that both hybrid individuals are F1 crosses (with R. palustris a R. sphenocephala respectively). Our data confirm the ability of R. areolata to hybridize with congeners in a wild population, and offer the first documentation of hybridization occurring in R. areolata. We demonstrate that contemporary gene flow may be important for divergent ranid frogs, and suggest that associated conservation implications may be present.
ABSTRACT: The Indiana DNR is launching a new headstarting program for Crawfish frogs (Lithobates areolatus), a state endangered species since 1988, with the purpose of reestablishing the species in extirpated areas within its historic range. Habitat conversion to agriculture has limited the ability of this species to disperse and recolonize areas of suitable habitat across the landscape. We plan to rear Crawfish frog tadpoles in outdoor mesocosms. These rearing methods are modeled after successful headstarting and reintroduction of Dusky Gopher frogs and Gopher frogs, two closely related species in the Southeastern U.S. We will complete a simple density-dependent tadpole rearing experiment to inform husbandry methods and conduct a chytrid/ranavirus coinfection trial to better understand how these endemic diseases may affect tadpole survival in the wild. Metamorphed froglets will be housed in a soft-release enclosures for two weeks at the reintroduction site before release. We are working closely with land managers to enhance Crawfish frog habitat through the creation and modification of breeding wetlands at recovery sites. After this initial pilot year, we will include a radiotelemetry study to better understand dispersal and survival. The Crawfish frog headstarting program in Indiana will build upon achievable initial goals to restore this species in an adaptive management framework.
AUTHORS: Joseph R. Robb, Big Oaks National Wildlife Refuge, U. S. Fish and Wildlife Service
ABSTRACT: The 50,000-acre Big Oaks National Wildlife Refuge (NWR) contains one of the largest populations of crawfish frogs (Lithobates areolatus) in Indiana. The crawfish frog, a state endangered species in Indiana, is a burrow obligate species that is currently declining throughout much of its range. Sporadic recruitment and woody habitat intrusion were likely responsible for limiting this population at Big Oaks NWR. We initiated several management and research projects to better understand and mitigate this issue during 2004-2024. Occupancy modeling identified focus areas for breeding wetland restoration where quality grassland habitat existed, but populations were absent. This modeling approach also identified aspects of breeding pond use where the most parsimonious model indicated that crawfish frogs selected relatively larger ephemeral wetlands, emergent vegetation present in less than 50% of the wetland, and the absence of woody vegetation. Combining this knowledge with the results from an early pilot project investigating how experimentally drained ponds increased crawfish frog use and reduced their predator and competitor communities, we designed and constructed breeding wetlands to improve the management of this species. We also used several head starting techniques to increase the productivity of this species in quality habitat. Monitoring of these breeding wetlands has shown newly established populations, increased breeding adult use, and increased recruitment. However, the potential for larval disease outbreaks (i.e., Perkinsea sp. and Ranavirus) complicates management. The success of this management regime could be replicated to restore populations in appropriate habitat to stabilize population declines throughout their range especially if management could be used to reduce disease outbreaks.
