Effects of Altosid and Abate-4E on Deformities and Survival in Southern Leopard Frogs Under Semi-Natural Conditions

Since 1995 when a group of school children in Minnesota found frogs with supernumerary limbs and missing limbs, there has been widespread interest in the amphibian malformation issue. Despite considerable effort to understand this problem, its extent and seriousness as well as direct causes of these malformations remain unclear. Progress on this issue has been hampered by a scarcity of scientifically reliable information on historical rates of abnormalities under undisturbed conditions and by the normal turnaround times of data collection, sample analysis and publication. One of the very few peer-reviewed publications with field-collected data showed that an average of 12% (range 0-69%) of the frogs inhabiting wetlands in southern Quebec, Canada had deformities, most of which consisted of partially or completely missing hind limbs or digits (Ouellet et al. 1997). The use of pesticides was correlated with these deformities, but no specific cause and effect relationships were developed

Reproductive Isolating Mechanisms and Communication in Greater Prairie Chickens (Tympanuchus Cupido) and Sharp-Tailed Grouse (Pedioecetes Phasianellus)

Sympatric populations of greater prairie chickens (Tympanuchus cupido) and sharp-tailed grouse (Pedioecetes phasianel lus) were studied between 1975 and 1978 in northwestern Minnesota for the pur poses of identifying and determining the strength of reproductive isolating mechanisms between them. Major emphasis was placed on ethological mechanisms but other factors were also examined. Approximately a fifth of the sharptail’s distribution overlaps half of the prairie chicken’s within North America. Within the zone of sympatry, prairie chicken populations are in small patches and may be liable to hybrid swarming, particularly with changes in land-use practices. The rate cf hybridization is around 1% but may be much greater in specific areas. Within the Minnesota study area, hybridization increased from 1-3.7% as the ratio between numbers of prairie chickens and sharptails increased. Habitat preferences and seasonal and daily patterns of activity were sufficiently similar between species to allow complete intermixing. Breeding experiments conducted in captivity showed that hybrids and backcrosses were interfertile. Thus, non-communica- tory mechanisms were weak or non-existent. Agonistic displays, including forward displays, face offs and stand offs were similar between SDecies and probably facilitated spacing as all males held interspecifically exclusive territories on mixed displa.- grounds. Most epigamic behaviors such as booming displays, whoops, dancing and chi Iks were polyvalent and had many species-specific characteristics. Discriminant analysis and canonical correlation analysis were used to show that whoops and chi Iks, which were mostly epigamic, were most different between species; whines, which were polyvalent, were more similar; and cackles, the most aggressive of the 3 sets of vocalizations, were most similar between species. Interrelationships of homologous displays, as determined by cluster analyses, and by temporal occurrence of common displays, were not sufficiently different to be effective isolating mechanisms. Displays of hybrids were intermediate in form between both parental species and may have repulsed females. Intraspecific playback experiments of vocalizations showed that prairie chicken booms, whoops and composite calls (consisting of a segment of a recording made while a prairie chicken hen visited a display ground) had agonistic functions. Prairie chicken whines also elicited significant responses but this call appeared to serve as an alarm. Sharptail males responded aggressively to gobbles, coos, cackles and alert. The functions of dancing in intermale communication were unclear. Analyses of activity rates showed that males of both species responded .tore vigorously to live and taxidermist mounts of conspe- cific hens than to heterospecifics. Male prairie chickens, unlike sharptails, frequently courted live heterospecific females, even if doing so led to fights. Prairie chicken males reacted aggressively to sharptail coos, gobbles, cork notes and composite sounds while sharp-tails only responded to prairie chicken cackles. Increased selectivity of sharptails for nonspecific stimuli may be due to greater historical contact with confamilials and a resulting channelization of reproduc tive and aggressive energies to meet intraspecific competition. During experiments conducted in captivity, females of both species strongly preferred conspecific territories and males despite being raised in mixed-species groups from hatching. FI hybrid and backcross females were more ambiguous but may have preferred sharp- tail males. Precise factors determining mate choice by females were unidentified but appeared to relate to possession of a territory and to behaviors of males. Of the mechanisms studied, behavior, particularly communication, seemed to be most important in maintaining species integrity between greater prairie chickens and sharp-tailed grouse. Based on similari ties in the displays of the two species and cn apparent fertility of hybrids, both grouse should be considered congeneric under Tympanuchus

Ontogenetic Patterns of Agonistic Behavior in a Guild of Larval Ambystomatid Salamanders

Agonistic behavior is a common feature of larval amphibians inhabiting temporary ponds. Given the temporally staggered sequence of hatching by pond-breeding amphibians, ontogenetic patterns of aggression can influence coexistence if larvae of certain species or ages are subject to increased aggression. To determine whether aggression changes through larval ontogeny, we observed agonistic behavior of Ambystoma opacum, Ambystoma tigrinum, and Ambystoma maculatum at four stages of development spanning the larval period. We tracked aggression rates among individual larvae to determine whether previous success, in the form of increased aggression, facilitated success in subsequent contests. All species exhibited distinct ontogenetic patterns of aggression, with the highest and lowest rates of aggression exhibited during rear leg development and metamorphosis, respectively. Species-specific aggression rates were observed, with A. tigrinum consistently displaying the highest levels of aggression. Winner or loser effects were not evident, because increased aggression early in the larval period did not result in increased aggression throughout ontogeny. We hypothesize that the observed patterns of behavior may represent a baseline level of aggression upon which other biotic and abiotic factors act in mediating coexistence among larval amphibians

Arthropod Consumption by Northern Bobwhite Chicks in Managed Tall Fescue Monocultures

An extensive amount of Conservation Reserve Program (CRP) habitat for northern bobwhite (Colinus virginianus) has been lost to planting of tall fescue (Schedonorus phoenix). We conducted foraging trials using human-imprinted bobwhite chicks (n 1⁄4 288) and collected terrestrial arthropods using a customized yard vacuum to assess the effects of 3 USDA mid-contract management (MCM) cost-share practices on chick foraging rates and arthropod prey selection in 36 tall fescue-dominated CRP fields in Illinois during 2008. We applied fall strip disking, fall glyphosate spraying, and fall glyphosate spraying followed by spring legume interseeding in alternating strips to 33% of each treatment field on a 3-year rotation. Glyphosate and glyphosate-interseeding treatments provided greater brood habitat benefits for bobwhite chicks than disking and control fields. Chicks consumed a greater abundance (P , 0.0001) and biomass (P 1⁄4 0.0017) of arthropods in managed fields than in unmanaged fields. Abundance and biomass of arthropods consumed by chicks were higher in glyphosate and glyphosate-interseeded strips with 1-, 2-, and 3-growing seasons post-treatment, but disking only provided this benefit for 1 growing season. Vacuum sampling provided a poor index of the availability of arthropods to bobwhite chicks, as measured by foraging of imprinted chicks. Vacuum sampling indicated arthropod abundance was greater in unmanaged than in managed fields (P 1⁄4 0.170). Custom vacuums are not an appropriate tool for measuring the abundance of arthropods important to bobwhite chicks in tall fescue CRP. Fall strip disking is an inferior MCM practice to glyphosate-based treatments in tall fescue- dominated CRP

Interactive Effects of Climate Change with Nutrients, Mercury, and Freshwater Acidification on Key Taxa in the North Atlantic Landscape Conservation Cooperative Region

The North Atlantic Landscape Conservation Cooperative LCC (NA LCC) is a public-private partnership that provides information to support conservation decisions that may be affected by global climate change (GCC) and other threats. The NA LCC region extends from southeast Virginia to the Canadian Maritime Provinces. Within this region, the US National Climate Assessment documented increases in air temperature, total precipitation, frequency of heavy precipitation events, and rising sea level, and predicted more drastic changes. Here, we synthesize literature on the effects of GCC interacting with selected contaminant, nutrient, and environmental processes to adversely affect natural resources within this region. Using a case study approach, we focused on 3 stressors with sufficient NA LCC region-specific information for an informed discussion. We describe GCC interactions with a contaminant (Hg) and 2 complex environmental phenomena-freshwater acidification and eutrophication. We also prepared taxa case studies on GCC- and GCC-contaminant/nutrient/process effects on amphibians and freshwater mussels. Several avian species of high conservation concern have blood Hg concentrations that have been associated with reduced nesting success. Freshwater acidification has adversely affected terrestrial and aquatic ecosystems in the Adirondacks and other areas of the region that are slowly recovering due to decreased emissions of N and sulfur oxides. Eutrophication in many estuaries within the region is projected to increase from greater storm runoff and less denitrification in riparian wetlands. Estuarine hypoxia may be exacerbated by increased stratification. Elevated water temperature favors algal species that produce harmful algal blooms (HABs). In several of the region\u27s estuaries, HABs have been associated with bird die-offs. In the NA LCC region, amphibian populations appear to be declining. Some species may be adversely affected by GCC through higher temperatures and more frequent droughts. GCC may affect freshwater mussel populations via altered stream temperatures and increased sediment loading during heavy storms. Freshwater mussels are sensitive to un-ionized ammonia that more toxic at higher temperatures. We recommend studying the interactive effects of GCC on generation and bioavailability of methylmercury and how GCC-driven shifts in bird species distributions will affect avian exposure to methylmercury. Research is needed on how decreases in acid deposition concurrent with GCC will alter the structure and function of sensitive watersheds and surface waters. Studies are needed to determine how GCC will affect HABs and avian disease, and how more severe and extensive hypoxia will affect fish and shellfish populations. Regarding amphibians, we suggest research on 1) thermal tolerance and moisture requirements of species of concern, 2) effects of multiple stressors (temperature, desiccation, contaminants, nutrients), and 3) approaches to mitigate impacts of increased temperature and seasonal drought. We recommend studies to assess which mussel species and populations are vulnerable and which are resilient to rising stream temperatures, hydrological shifts, and ionic pollutants, all of which are influenced by GCC

Interactive Effects of Climate Change with Nutrients, Mercury, and Freshwater Acidification on Key Taxa in the North Atlantic Landscape Conservation Cooperative Region

The North Atlantic Landscape Conservation Cooperative LCC (NA LCC) is a public–private partnership that provides information to support conservation decisions that may be affected by global climate change (GCC) and other threats. The NA LCC region extends from southeast Virginia to the Canadian Maritime Provinces. Within this region, the US National Climate Assessment documented increases in air temperature, total precipitation, frequency of heavy precipitation events, and rising sea level, and predicted more drastic changes. Here, we synthesize literature on the effects of GCC interacting with selected contaminant, nutrient, and environmental processes to adversely affect natural resources within this region. Using a case study approach, we focused on 3 stressors with sufficient NA LCC regionspecific information for an informed discussion. We describe GCC interactions with a contaminant (Hg) and 2 complex environmental phenomena—freshwater acidification and eutrophication. We also prepared taxa case studies on GCCand GCC-contaminant/nutrient/process effects on amphibians and freshwater mussels. Several avian species of high conservation concern have blood Hg concentrations that have been associated with reduced nesting success. Freshwater acidification has adversely affected terrestrial and aquatic ecosystems in the Adirondacks and other areas of the region that are slowly recovering due to decreased emissions of N and sulfur oxides. Eutrophication in many estuaries within the region is projected to increase from greater storm runoff and less denitrification in riparian wetlands. Estuarine hypoxia may be exacerbated by increased stratification. Elevated water temperature favors algal species that produce harmful algal blooms (HABs). In several of the region\u27s estuaries, HABs have been associated with bird die-offs. In the NA LCC region, amphibian populations appear to be declining. Some species may be adversely affected by GCC through higher temperatures and more frequent droughts. GCC may affect freshwater mussel populations via altered stream temperatures and increased sediment loading during heavy storms. Freshwater mussels are sensitive to un-ionized ammonia that more toxic at higher temperatures. We recommend studying the interactive effects of GCC on generation and bioavailability of methylmercury and how GCC-driven shifts in bird species distributions will affect avian exposure to methylmercury. Research is needed on how decreases in acid deposition concurrent with GCC will alter the structure and function of sensitive watersheds and surface waters. Studies are needed to determine how GCC will affect HABs and avian disease, and how more severe and extensive hypoxia will affect fish and shellfish populations. Regarding amphibians, we suggest research on 1) thermal tolerance and moisture requirements of species of concern, 2) effects of multiple stressors (temperature, desiccation, contaminants, nutrients), and 3) approaches to mitigate impacts of increased temperature and seasonal drought. We recommend studies to assess which mussel species and populations are vulnerable and which are resilient to rising stream temperatures, hydrological shifts, and ionic pollutants, all of which are influenced by GCC

Pesticides Are Involved With Population Declines of Amphibians in the California Sierra Nevadas

Several species of frogs and toads are in serious decline in the Sierra Nevada Mountains of California. These species include the threatened red-legged frog (Rana aurora), foothill yellow-legged frog (R. boylii), mountain yellow-legged frog (R. muscosa), Cascades frog (Rana cascadae), western toad (Bufo boreas) and Yosemite toad (B. canorus). For many of these species current distributions are down to 10% of historical ranges [1,2]. Several factors including introduced predators [3,4,5], habitat loss [2], and ultraviolet radiation [6] have been suggested as causes of these declines. Another probable cause is air-borne pesticides from the Central Valley of California. The Central Valley, especially the San Joaquin Valley, is a major agricultural region where millions of pounds of active ingredient pesticides are applied each year (http://www.cdpr.ca.gov/dprdatabase.htm). Prevailing westerly winds from the Pacific Coast transport these pesticides into the Sierras [7,8]