Migratory amphibians are at high risk of negative impacts when roads intersect their upland and breeding habitats. Road mortality can reduce population abundance, survivorship, breeding, recruitment, and probability of long-term persistence. Increasingly, environmental planners recommend installation of under-road tunnels with barrier fencing to reduce mortality and direct amphibians towards the passages. Often, the permeability of these barrier and passage systems to amphibian population movements are unknown. We studied the movements of California tiger salamanders (CTS: Ambystoma californiense) in relation to solid and mesh barrier fencing attached to a 3-tunnel system between upland and breeding habitats in Stanford, California. We deployed active-trigger cameras along the fencing, used pattern recognition software to identify individuals by their unique spot patterns, and calculated individual salamander movement distances, speed, direction changes, and “success” at reaching the tunnel system. We found that migrating adult CTS moved an average of 40 m along barrier fencing before turning back into the habitat or “giving-up”. This short distance, in comparison to long migratory movements, may be explained by the orientation mechanisms salamanders use to reach their breeding sites. The probability CTS found a passage decreased rapidly with increasing distance from the tunnel system, particularly if individuals turned the “wrong” way after encountering the fence. Salamanders changed directions more often and spent more time along mesh fencing. Our results suggest that a maximum of 12.5 m between passages along CTS migration routes should allow approximately 90% of adult salamanders to encounter road crossings. Additionally, use of solid fencing or a visual barrier on mesh fencing may help to lead salamanders to passages most efficiently. These considerations can assist those seeking to design effective road mitigation for CTS and other migratory amphibians.

Assessing causes of population decline is critically important to management of threatened species. Stochastic patch occupancy models (SPOMs) are popular tools for examining spatial and temporal dynamics of populations when presence-absence data in multiple habitat patches are available. We developed a Bayesian Markov chain method that extends existing SPOMs by focusing on past environmental changes that may have altered occupancy patterns prior to the beginning of data collection. Using occupancy data from 3 creeks, we applied the method to assess 2 hypothesized causes of population decline-in situ die-off and residual impact of past source population loss-in the California red-legged frog. Despite having no data for the 20-30 years between the hypothetical event leading to population decline and the first data collected, we were able to discriminate among hypotheses, finding evidence that in situ die-off increased in 2 of the creeks. Although the creeks had comparable numbers of occupied segments, owing to different extinction-colonization dynamics, our model predicted an 8-fold difference in persistence probabilities of their populations to 2030. Adding a source population led to a greater predicted persistence probability than did decreasing the in situ die-off, emphasizing that reversing the deleterious impacts of a disturbance may not be the most efficient management strategy. We expect our method will be useful for studying dynamics and evaluating management strategies of many species.

Chloropyron palmatum (Ferris) Tank & J.M Egger (formerly Cordylanthus palmatus [Ferris] J. F. Macbr.) is an annual plant that inhabits seasonally flooded wetlands with saline and alkaline soils in California. In 1986, the plant was listed as endangered under the U.S. Endangered Species Act. We aimed to inform conservation strategies for the species’ five remaining populations by examining the genetic diversity and structure of the populations (on the basis of nuclear DNA markers) and their potential response to demographic and environmental stochasticity. We also assessed fluctuations in population size and whether there was evidence of hybridization between C. palmatum and Chloropyron molle (A. Gray) A. Heller subsp. hispidum (Pennell) Tank & J.M. Egger (formerly Cordylanthus mollis A. Gray subsp. hispidus [Pennell] T.I. Chuang & Heckard). Populations of C. palmatum were genetically distinct with a FST of 0.23, indicating substantial genetic structure among populations. Within populations, there was no evidence of isolation by distance. However, individuals in two adjacent vernal pools were genetically distinct. The pattern of genetic variation within populations suggests that the historical frequency and extent of seed dispersal by overland flooding has strongly affected the genetic structure of populations. Despite founder effects and population bottlenecks, small and large populations had similar levels of genetic variation. We found no evidence of hybridization. All extant populations of C. palmatum are genetically variable and distinct. We recommend that hydrologic connectivity be considered if seeds are collected and sowed with the intent of increasing the size of natural populations or creating experimental populations.

Stream water temperature regimes are determined by the complex interplay of various environmental factors, including prevailing meteorology, surface and subsurface flow patterns, and local riparian canopy structure as it affects solar exposure. We examined temperature regimes with respect to conservation of aquatic organisms for San Francisquito Creek (SFC) watershed (San Francisco Peninsula, CA) using a stream temperature characterization protocol that predicts water temperature regimes for any time period and location The protocol predicts stream temperature dynamics based on energy balance, with a focus on shortwave input from incoming solar radiation (insolation). Analyses synthesize measurements of meteorology from nearby weather stations, stream flow and water temperature from gaging stations, water temperature from a distributed sensor network, riparian canopy structure and solar exposure from hemispherical photography, and stream morphology from field characterization and geographic information system (GIS) analysis. For SFC, water temperature generally tracked air temperature, with significant lags (~ 4+ hr) and local effects. Subsurface flow through gravel beds decreased temperature (2-3° C decrease) and greatly lowered temperature variability. Stream reaches with open riparian canopy had high insolation and displayed relatively high temperature variability (up to 5° C differential from baseline), whereas reaches with closed canopy had low insolation and displayed modest temperature variability (0.5-1.0° C differential). Simulated tree removal demonstrates the power of the tool to evaluate human and natural impacts of riparian canopy modification. Analysis of the July 2006 heat wave demonstrates the value of the protocol for assessing impacts of extreme weather events. Management of SFC stream habitat to include a diversity of suitable temperature regimes is essential for conservation of species such as steelhead trout (Oncorhynchus mykiss), which requires relatively cool conditions, and California red-legged frog (Rana aurora draytonii) and western pond turtle (Clemmys marmorata), which require warmer conditions. Our stream temperature characterization protocol not only is valuable for the SFC watershed, but also can be applied to a broad spectrum of streams for habitat assessment, for conservation and restoration, and for examination of potential impacts of climate change on stream ecosystems.

Cordylanthus palmatus is an annual plant that inhabits seasonally flooded wetlands with saline and alkaline soils in California, USA. In 1986, the plant was listed as endangered due to the small size or threats to its five remaining populations. The goal of our research was to inform conservation strategies by examining genetic diversity and structure and their potential response to demographic and environmental stochasticity. We used nuclear DNA markers to measure genetic characteristics. To explore potential influences on genetic variation and structure we assessed fluctuations in population size and interspecific hybridization between C. palmatus and C. mollis ssp. hispidus. We found geographically separate populations of C. palmatus were genetically distinct, with a FST of 0.23, indicating substantial genetic structure among populations. Within populations, there was no evidence of isolationbydistance. However, two adjacent vernal pools contained genetically distinct sub-populations. Overall, the pattern of genetic variation within populations supported the hypothesis that the historical frequency and extent of seed dispersal by overland flooding has influenced population genetic structure strongly. Despite founder effects and population bottlenecks, small populations maintained levels of genetic variation comparable to large populations. We found no evidence of hybridization between the congeners. All extant populations of C. palmatus are genetically variable and distinct. We recommend that hydrologic connectivity be considered in collection and sowing of seeds intended to increase the abundance of in situ populations or to create experimental ex situ populations.

Abstract The research reported in this volume began more than 40 years ago with studies of the Bay checkerspot butterfly, a subspecies of the widely distributed Edith’s checkerspot butterfly. Working initially with the populations on Stanford University’s Jasper Ridge Biological Preserve, Ehrlich and colleagues asked some fundamental questions: why does the Bay checkerspot butterfly inhabit the area that it does? Why does it not occur elsewhere? Why is it sometimes abundant and sometimes rare? How does population size relate to genetic variability? Are these populations evolving at a rate that can be detected on an ecological time scale? Answers to such questions from checkerspots and other well-selected systems have helped produce a comprehensive picture of how the world works at the population level. As research on the Bay checkerspot proceeded, however, many questions took on new applied and conservation significance. Work at Jasper Ridge and other sites established that Edith’s checkerspot butterfly populations were quite unstable and that many habitats were threatened by human development and habitat degradation. Most recently, the Jasper Ridge populations that were the focus of the Ehrlich group’s long-term study have become extinct.

1. A sequence of population estimates for two now-extinct populations of Euphydryas editha bayensis is presented. After removing biased sampling days, estimates of demographic parameters from the long-term data were used to test five hypotheses built from studies of shorter duration. Such tests of short-term conclusions are rare.2. The long-term demographic parameters include sex ratio, mortality, dispersal, mean flight date, and duration of flight season. The two populations differed with respect to sex ratio and mean flight date, and sexes differed with respect to mortality and dispersal.3. Three of the five hypotheses were supported directly or indirectly by patterns in the parameters. These hypotheses predict that dynamics are asynchronous over the long term, that larval mortality, not adult abundance and mortality, is the primary determinant of changes in population size, and that topography mediates larval mortality.4. Two hypotheses were not supported or supported only in part. Flight phenology differed between the study populations as predicted, but flight order was opposite that expected from the topographic composition of each habitat. Variability in sex ratio and the occurrence of female-biased ratios in the habitat of one of the populations also suggest that previous observations of sex ratio are not generalisable.5. Populations were extremely volatile over the study period. Removal of biased sampling days did not change basic trends or fluctuations in the data. This volatility suggests that E. editha populations residing in similar habitats may risk immediate extinction.

We analyzed genetic variability among the four naturally-occurring populations of the endangered plant Cordylanthus palmatus to test whether a central tenet of conservation genetics - large populations are more genetically diverse than small populations held true in our study system and to guide long-term conservation planning for the species. Genetic variability in C. palmatus was moderate at the species level but relatively low in several populations. About 2% of the measured genetic variation was attributable to variation between populations. Genetic variability in C. palmatus did not increase with population size. The two largest populations were relatively invariate and genetically similar, and neither contained any unique alleles. (C) 2001 Elsevier Science Ltd. All rights reserved.

In California, overwintering tadpoles have been reported for only two ranid species: Rana muscosa (mountain yellow-legged frog) (Stebbins 1985) and R. catesbeiana (bullfrog) (Behler and King 1979; Leonard et al. 1993). Storer (1925) states that R. aurora spend 4-5 months as larae with metamorphosis typically takng place between July and September. We report here our observations of Rana aurora draytonii (California red-legged frog) tadpoles overwintering at 11 sites spread over four counties in central coastal California. We define overwintering as spending the winter (November-February) in the larval stage (:: Gosner stage 40; Gosner 1960). One site is located in a spring-fed pool that drains into Matadero Creek (Santa Clara Co., 37°24', 122°10', 200 m elevation). On Mar 20, 1998 we caught two distinct size classes of tadpoles, five small individuals (approximately 30 mm TL), and two large ones (72 mm and 92 mm TL; Gosner stages 36 and 38 respectively). There was also a recently metamorphosed R. aurora (28 mm SVL). On Oct 15, 1999 we found a tadpole with only rudimentar hind limbs (Gosner 36). The pool measured 3 x 5 m and was ::1.0 m deep. It was heavily shaded with California blackberr (Rubus ursinus), wilow (Salix sp.), and poison oak (Toxicodendron diversilobum). On Nov 3, 1999 a 65 mm tadpole was caught at one of several pools along alSO m stretch of Round Valley Creek (Contra Costa Co., 37°52', 121 °46', 128 m elevation). The tadpole had only small hind limb buds (Gosner 32). On Dec 15, 1999 an additional three tadpoles (Gosner 36-37) were captured in the same creek, and on J an 7, 2000 one Gosner stage 39 tadpole was found. The creek ran through an oak savannah woodland, which was seasonally grazed by cattle. Two of the pools were ::1.0 meter deep including the one where the tadpole was captured. Prior observations indicate that tadpoles have overwintered at this site each year since 1997. Recent metamorphs have been found in April, much too early to be young of that year because eggs are typically laid at this site during March. During winter storms, the creek carres a substantial amount of water and rises as much as a vertical meter, at least for short periods of time. It is not clear how R. aurora tadpoles

Increasing reports of amphibian limb malformations from many parts of North America have prompted investigations into the potential causes of these abnormalities and their implications for amphibian populations. Over a two-year period, we monitored the frequency and composition of morphological abnormalities in four amphibian species (Hyla regilla, Taricha torosa, Bufo boreas, and Rana catesbeiana) from two California ponds. The frequency of abnormalities differed significantly by species, life-history stage, pond, and season. Generally, the frequency and severity of abnormalities were greater in the amphibians from Frog Pond over those from Hidden Pond, and in lan,al stages over emerging and adult amphibians. Larvae of T. torosa exhibited the highest rate of abnormalities, ranging from 15-50%, followed by larval and metamorphic H. regilla (10-25%), and finally by metamorphic B. boreas and R. catesbeiana, both of which had rates of less than five percent. Within each species, the composition of abnormalities was strongly consistent between years, ponds, and early life-history stages. We recorded the most severe malformations in H. regilla, and more than 60% of the abnormalities in treefrogs involved extra hindlimbs, femoral projections, and skin webbings. Similarly severe, the abnormalities of R. catesbeiana wore dominated by extra and missing hind- and forelimbs. In B. boreas and T torosa, the most common morphological abnormalities were missing limbs and digits, which accounted for approximately 75% and 95%, respectively., of their total abnormalities. Potential causes of the observed abnormalities, including infection by the trematode Ribeiroia, and the conservation significance of amphibian malformations are discussed.

We tested empirically whether microclimate and relative timing of oviposition affected prediapause larv^al survival and development rates in the federally threatened Bay checkerspot butterfly, Euphydryas editha bayensis (Nymphalidae).Most mortality in Bay checkerspot butterflies occurs among prediapause larvae.Because phenology of the butterfly's lan^al hostplant, Plantago erecta, has been thought to drive prediapause larval survival patterns, we also tested whether P. erecta senescence and density over time varied among microclimatic zones.We found that microclimate had a significant effect on P. erecta phenolog)'.Changes in density of edible P. erecta among microclimatic zones were out of phase temporally, but otherwise were similar.In the year of our study, neither microclimate nor oviposition date tended to affect prediapause laiwal survival, but both variables had significant effects on prediapause larval development rates.Because temperature and precipitation patterns in the butterfly's environment vary' from year to year, whether microclimate and oviposition date significantly affect prediapause larval survival and development also may vary' annually.At least in some years, however, senescence of P. erecta may not cause prediapause larval mortality.Our results support the hypothesis that topographic heterogeneity is critical to the long-term viability of the Bay checkerspot butterfly as well as other species that inhabit temporally variable environments.

Conservation BiologyVolume 13, Issue 2 p. 450-452 Conservation in Practice: Overcoming Obstacles to Implementation Erica Fleishman, Erica Fleishman Center for Conservation Biology, Department of Biological Sciences, Stanford University,Stanford, CA 94305, U.S.A. Search for more papers by this authorGary H. Wolff, Gary H. Wolff Center for Conservation Biology, Department of Biological Sciences, Stanford University,Stanford, CA 94305, U.S.A. Search for more papers by this authorCarol L. Boggs, Corresponding Author Carol L. Boggs Center for Conservation Biology, Department of Biological Sciences, Stanford University,Stanford, CA 94305, U.S.A. And Rocky Mountain Biological Laboratory, Crested Butte, CO 81224, U.S.A.Search for more papers by this authorPaul R. Ehrlich, Paul R. Ehrlich Center for Conservation Biology, Department of Biological Sciences, Stanford University,Stanford, CA 94305, U.S.A. Search for more papers by this authorAlan E. Launer, Alan E. Launer Center for Conservation Biology, Department of Biological Sciences, Stanford University,Stanford, CA 94305, U.S.A. Search for more papers by this authorJohn O. Niles, John O. Niles Center for Conservation Biology, Department of Biological Sciences, Stanford University,Stanford, CA 94305, U.S.A. Search for more papers by this authorTaylor H. Ricketts, Taylor H. Ricketts Center for Conservation Biology, Department of Biological Sciences, Stanford University,Stanford, CA 94305, U.S.A. Search for more papers by this author Erica Fleishman, Erica Fleishman Center for Conservation Biology, Department of Biological Sciences, Stanford University,Stanford, CA 94305, U.S.A. Search for more papers by this authorGary H. Wolff, Gary H. Wolff Center for Conservation Biology, Department of Biological Sciences, Stanford University,Stanford, CA 94305, U.S.A. Search for more papers by this authorCarol L. Boggs, Corresponding Author Carol L. Boggs Center for Conservation Biology, Department of Biological Sciences, Stanford University,Stanford, CA 94305, U.S.A. And Rocky Mountain Biological Laboratory, Crested Butte, CO 81224, U.S.A.Search for more papers by this authorPaul R. Ehrlich, Paul R. Ehrlich Center for Conservation Biology, Department of Biological Sciences, Stanford University,Stanford, CA 94305, U.S.A. Search for more papers by this authorAlan E. Launer, Alan E. Launer Center for Conservation Biology, Department of Biological Sciences, Stanford University,Stanford, CA 94305, U.S.A. Search for more papers by this authorJohn O. Niles, John O. Niles Center for Conservation Biology, Department of Biological Sciences, Stanford University,Stanford, CA 94305, U.S.A. Search for more papers by this authorTaylor H. Ricketts, Taylor H. Ricketts Center for Conservation Biology, Department of Biological Sciences, Stanford University,Stanford, CA 94305, U.S.A. Search for more papers by this author First published: 24 December 2001 https://doi.org/10.1046/j.1523-1739.1999.013002450.xCitations: 7Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume13, Issue2April 1999Pages 450-452 RelatedInformation

The causes of amphibian deformities and their role in widespread amphibian declines remain conjectural. Severe limb abnormalities were induced at high frequencies in Pacific treefrogs (Hyla regilla) exposed to cercariae of a trematode parasite (Ribeiroia sp.). The abnormalities closely matched those observed at field sites, and an increase in parasite density caused an increase in abnormality frequency and a decline in tadpole survivorship. These findings call for further investigation of parasite infection as a cause of amphibian deformities in other sites and species.

A total of 384 species of Hesperiidae (Lepidoptera) have been recorded in the literature as occurring in Guatemala. Nearly 200 additional species occur in the adjacent countries of Belize, El Salvador, and Honduras, in the southernmost states of Mexico, or both north and south of Guatemala, and many of these will likely be recorded in the country with additional field work and continuing searches of museum collections.

We examined the distribution and abundance of butterfly species across an urban gradient and concomitant changes in community structure by censusing the butterfly and skipper populations at 48 points within six sites near Pale Alto, California, USA (all former oak woodlands). These sires represent a gradient of urban land use running from relatively undisturbed to highly developed and include a nature preserve, recreational area, golf course, residential neighborhood, office park and business district.The species richness and Shannon diversity of butterflies peaked at moderately disturbed sites while the relative abundance decreased from the natural to the urban areas. Butterfly species thought to be most representative of the original, predevelopment butterfly fauna progressively disappear as the sites become more urban. These patterns ave significantly related to shifts in habitat structure that occur along the gradient as determined by canonical correspondence analysis (CCA) using the environmental variables of percent land covered by pavement, buildings, lawn, grasslands, and trees or shrubs. The mechanisms behind these patterns may be related to life history and resource use by the individual butterfly species. (C) 1997 Published by Elsevier Science Ltd.

An inventory of the butterflies of Tikal National Park and vicinity, in the Department of Peten in northern Guatemala, is being conducted as part of a long-term study of butterfly populations, their habitat requirements, and their responses to land use changes. Here, we present a list of 535 species recorded from the Tikal area from February 1992 through November 1994 with annotations on their phenologies, habitat associations, and relative abundances. This is the first checklist of butterflies for any region of Guatemala, and includes 92 species not previously recorded from the country. Species richness for the Tikal site is greatest during the dry season and lowest at the end of the wet season. The largest number of species was recorded from forest edge habitat and the smallest was in forested habitats. Many species (especially nymphalids) were encountered in both primary forests and secondary, often highly disturbed, forests. Se realize un inventario de las mariposas diurnas del Parque Nacional Tikal y areas aledanas en el Departamento de Peten en el norte de Guatemala, como inicio de un estudio a largo plazo de las poblaciones de mariposas y su respuesta a los cambios del uso de la tierra. Se presenta una lista de 535 especies registradas en el area de Tikal desde febrero de 1992 hasta noviembre de 1994, con observaciones sobre su fenologfa, asociaciones con habitats, y su abundancia relativa. Esta es la primera lista de mariposas diurnas de una region de Guatemala. La lista incluye 92 especies registradas por la primera vez en Guatemala. La riqueza de especies es mayor en la epoca seca y menor al final de la epoca lluviosa. El mayor numero de especies se registro en los habitats de borde, y el menor numero en el interior del bosque. Muchas especies (particularmente Nymphalidae) comparten tanto el bosque primario como el secundario y tambien el bosque alterado.