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Royal catchfly (Silene regia, Caryophyllaceae) is a rare, tap-rooted, perennial forb known to occupy Midwestern prairies, glades, and savannas, which are increasingly fragmented. Though not federally listed, it is recognized as rare, threatened, or endangered in six states. We resurveyed 15 populations identified in 1980s–1990s monitoring at Wilson's Creek National Battlefield, Republic, MO. Abundance at each site was collected in 6 y (1988–1989, 1998–2000, 2019); measures of plant height and stems browsed were collected in 4 y (1998–2000, 2019). Fire history and precipitation were also explored. Mean royal catchfly abundance per population declined significantly over the study period, and only five of 15 populations supported extant populations in 2019. Year, site location, and the interaction between the two were highly significant factors in explaining variation of height measures and proportion of stems browsed. Plant height was significantly higher in 2019 than any other year, corresponding with overgrowth of competing vegetation and a wet spring. Prescribed fires became less frequent over the study period, and the mean fire return interval was higher than the historical regime of the region (9.7 y vs. 4–8 y). The decline of royal catchfly at Wilson's Creek National Battlefield and similar sites points to the need for fire management and restoration of prairie and savanna ecosystems for the persistence of this rare species.
Jackson County is the northeasternmost county of Alabama, U.S.A., and falls entirely in the southern portion of the Appalachian Plateaus physiographic province. Based on multiple years of fieldwork, herbarium work, and review of online (digitized) specimens, this study presents the diversity, habitats, biogeography, and conservation status of Carex in Jackson County. We document 90 Carex taxa from Jackson County by voucher specimens deposited in multiple herbaria. This value exceeds the number of taxa known from other, similar-sized regions in the southern part of the Appalachian Plateaus. Carex albicans var. emmonsii is a new state record and is known in Alabama only from Jackson County. We encountered high numbers of misidentifications among specimens collected prior to this study and exclude nine taxa previously reported from Jackson County that are based on misidentifications. Carex plants grow in a great number of habitats in Jackson County, with two hosting the greatest number of taxa: mature, wet-mesic, deciduous, floodplain forests on clays and clay loams; and mature, mesic, calcium-rich, deciduous, upland forests on loams. Jackson County is a nexus for both southeastern endemics and taxa occurring at or near their southern limits. Thirteen of the Carex taxa are rare in Alabama and likely of conservation concern in the state. This study contributes fundamental knowledge that makes sedge diversity, ecology, geography, and conservation better known, and is especially important for revealing a significant center of Carex diversity in North America.
Grazing differentially affects both the abundance and breeding success of grassland birds (e.g., due to differences in bird species' preferences for sparse or dense vegetation structure, nest predator response to grazing, and/or trampling of nests). Coupled with prescribed fire, grazing impacts can be compounded by pyric herbivory—the preference of grazers to choose newly-burned sites in which to graze. The purpose of this study was to determine how a recent re-introduction of American bison (Bison bison) coupled with prescribed fire may impact grassland bird nests. Artificial nests were used to determine if grazing and fire impacted nest success, total mammalian depredation, and depredation by the most common nest predator, mice (Peromyscus spp.). Artificial nests were placed in sites with and without bison before (2014) and after bison re-introduction (2015–2018); sites had fire return intervals from 1–2 y. We found the re-introduction of bison had a negligible influence on nest success and total mammalian depredation. However, nest success was lower in burned sites compared to unburned sites. The decrease in nest success correlated with an increase in total proportion of depredation events in burned sites compared to unburned sites. In addition, the proportion of Peromyscus spp. depredation events was marginally higher in burned sites compared to unburned sites. Although predation by Peromyscus increased after bison re-introduction, prescribed fire differences drove this change. Our results suggest prescribed fire may increase nest predation of artificial nests, indicating a possible impact on ground-nesting grassland birds. In contrast, bison had a negligible impact on artificial nest success in the first 4 y following their re-introduction.
The Allegheny woodrat (Neotoma magister) is a species of high conservation concern and relatively well-studied with respect to habitat use/associations, food habits, conservation genetics, and population trends. However, with the exception of raccoon roundworm (Baylisascaris procyonis) occurrence and etiology in woodrats, most disease and parasite ecology aspects for the woodrat are unknown. Herein, we examined the prevalence of bot flies (Cuterebra) over nearly three decades of woodrat surveys (1990–2018) in the central Appalachian Mountains of western Virginia. We use genetic analyses to identify recent bot fly specimen collections from a woodrat captured in 2017. Though highly variable from year to year, the overall prevalence of parasitism was low (typically < 4% of captures). As such, bot flies do not appear to be a widespread parasitic burden to Allegheny woodrats in Virginia. Genetic analysis of four collected bot fly larvae was inconclusive, as the genetic signature of these woodrat bots did not match any of the six bot species known to parasitize rodents and lagomorphs in the eastern United States. Further collections and genetic analyses will be needed to determine if the genetic database is incomplete or incorrect, or if our find is a new species of bot fly not yet taxonomically recognized.
Aquatic ecosystems with long hydraulic residence times (e.g., wetlands and reservoirs) can be important nitrogen (N) sinks via denitrification. The objective of this study was to examine denitrification rates of two small reservoirs (Springville and McDill) in central Wisconsin. Sediments, water chemistry, and discharge data were collected once per month between May and September of 2014 to achieve these objectives. Denitrification rates and microbial biomass carbon were not different between Springville and McDill; however, organic matter was significantly higher in McDill. Average denitrification rates were low at both sites, but ranged widely in Springville (0–23.72 mg N m–2 h–1) and less so in McDill (0.32–12.16 23 mg N m–2 h–1). Low denitrification rates in Springville may be the result of several locations being organic matter limited, whereas the McDill site was likely nitrate limited. Results from this study suggest reservoirs in central Wisconsin that are groundwater fed with sandy substrate have the potential to be nitrate sinks, but variation in the landscape (e.g. land use) and within each reservoir is influencing the magnitude of realized denitrification capabilities.
Relatively few North American anurans overwinter in water and information is sparse on their movement from overwintering habitat to breeding sites. Oregon spotted frogs (Rana pretiosa) breed explosively in early spring and often overwinter submerged at sites that are distanced from breeding habitats. In montane parts of their range, wintering and breeding habitats can remain frozen for months. We investigated timing, duration, and potential cues for R. pretiosa migrations from a wintering lake near the Cascade Mountains in central Oregon, U.S.A. First and median migrant males moved slightly earlier than females. Onset of migration was as early as February 12 (males) and as late as April 4 (females) in years of mild and extended winters, respectively. Frogs were active at water temperatures below those associated with early breeding activities in one lowland R. pretiosa population. Higher proportions of frogs migrated before ice-out in years of prolonged winter conditions. Migrations were temporally compressed in years of later movement. This migration ‘rush’, along with the ability to move at cold temperatures and to vary timing of migrations likely helps montane R. pretiosa deal with colder and more variable spring conditions than lowland populations.
The reproductive biology of lampreys is of special interest given the group has retained many developmental features reminiscent of the earliest vertebrates. Herein I report spawning behavior in the Least Brook Lamprey (Lampetra aepyptera) from southern Indiana and provide descriptions of its embryonic development. Nesting activities began in mid-March when water temperatures ranged from 10 to 12 C, as two or more individuals dug out shallow depressions in loose gravel immediately above riffles. Communal spawning groups (>10 individuals) subsequently formed at the nest sites when the water temperature rose above 12 C. Embryos generated from the gametes of spawning adults underwent gastrulation 72 h after fertilization, neurulation after 6 d, and hatched after 14 d. Prolarvae developed melanophores 19 d after fertilization, eyespots were visible by 20 d, and the velum began to beat 25 d after fertilization. Expulsion of yolk from the intestine and filter feeding occurred 26 d after fertilization. Embryonic development in L. aepyptera largely matches the embryonic stages established for the Sea Lamprey (Petromyzon marinus), with subtle differences in the sequence of specific developmental features. These descriptions clarify conflicting accounts of spawning activities for L. aepyptera and provide staging criteria for future investigations into its embryonic development.
A tooth of Phoebodus cf. P. sophiae (Chondrichthyes, Elasmobranchii) was recovered from the Middle Devonian, Early Givetian, Rockport Quarry Limestone Formation in Alpena, Michigan. It is the first known record of the taxon in Michigan and the third known locality from North America. It is the oldest known record in North America, and possibly worldwide, and may extend the known temporal range of the genus. Previous known records for P. sophiae have been confined to the middle Givetian Polygnathus varcus conodont zone, and the taxon was thought to be a possible index fossil for the middle Givetian. The present record extends the taxon to the early Givetian P. hemiansatus conodont zone and, thus, complicates the use of P. sophiae as a proxy index fossil for the P. varcus zone.
The Common Black Hawk (Buteogallus anthracinus), a widespread neotropical raptor, has been known since the 1970s to nest as far north as western Texas, but few breeding records exist for the adjacent area of northcentral Mexico. In 2015 we located two active nest sites within the Maderas del Carmen Flora and Fauna Protection Area at northwestern Coahuila. The nest sites were in Pecan (Carya illinoiensis) and Arizona Pine (Pinus arizonica) trees, both near natural permanent water sources. Our recent nest site records along with others in eastern Coahuila suggest the existence of a corridor connecting Texas and Nuevo León populations, highlighting the importance of transboundary natural protected areas for species conservation.
There is limited knowledge on the winter distribution of LeConte's Sparrow, especially in northern Mexico where it is considered scarce and rare. We captured and banded two individuals of LeConte's Sparrow (Ammospiza leconteii) during consecutive winters (2016-2017, 2017-2018; one in each season) in an intermountain grassland of northern Coahuila, Mexico. These records were ca. 300 km outside the known wintering range of this species. Vegetation was variable at both sites. The first wintering site consisted of low grass cover (18.7%) dominated by Eragrostis and Bouteloua; the second site consisted of 72.6% grass cover, mainly composed of Bouteloua and Botriochloa.