Post-breeding season movements of Columbia spotted frogs ( Rana luteiventris ) in northeastern Oregon

Movements of Columbia spotted frogs ( Rana luteiventris ) were determined after breeding to provide managers with information on habitat requirements. We radio-tagged 47 adults and observed movements occurring with 22 frogs. Eleven frogs remained in breeding ponds, and 11 moved to other ponds or river stretches during spring and summer 1998. Distances frogs traveled to other water bodies ranged from 15 to 560 m. Movements appeared to be influenced by availability of habitat and aquatic conditions. Eleven of 16 frogs located within 100 m of other permanent water sources moved, while no frogs at an isolated breeding pond moved. Frogs moved to river stretches in July where water temperatures averaged 5.6 ° C cooler than ponds. Knowledge of Columbia spotted frog movements and habitat use in summer enables land managers to make decisions on activities that affect aquatic sites, vegetation, and stream structures that may influence frog populations.     

Characteristics of Columbia spotted frog ( Rana luteiventris ) oviposition sites in northeastern Oregon, USA

Several western ranid frogs possess a unique strategy of breeding communally over a short temporal window and reusing oviposition sites between years. However, little is published on the characteristics of oviposition sites selected by these explosive breeders. The Columbia spotted frog ( Rana luteiventris ) is native to northwestern North America and is of conservation concern in the southern portions of its range. As part of a study examining relationships between livestock grazing and R. luteiventris habitat, we assessed characteristics of the species' oviposition sites in 25 fishless ponds in northeastern Oregon. Oviposition sites were generally in shallow water (<25 cm) close to shore and tended to be in the northeastern portion of ponds. Oviposition sites were found more frequently over heavily vegetated substrates and in areas of less substrate slope and shade than random points in littoral zones. We did not quantify temperature differences within ponds, but the patterns we documented are consistent with preferential use of warmer microhabitats for oviposition.     

Aquatic habitats, life history observations, and zoogeographic considerations of the spotted frog ( Rana pretiosa ) in Tule Valley, Utah

Four populations of the spotted frog, Rana pretiosa , occur in western Bonneville Basin. Only the Tule Valley populations occupy aquatic habitats associated with warm (28°C) and slightly saline (1700-2700 μmhos/cm) springs. The spotted frog in Tule Valley breeds in cold-water portions of the peripheral wetlands, which exhibit maximum temperature variations (1-25°C), maximum conductivity up to 3200 μmhos/cm, and maximum pH values up to 9.7. Adult frogs are found in habitats with temperatures of 29°C, conductivity of 4700 μmhos/cm, and pH above 9.0 in the summer. The increased summer salinity and pH in frog habitats returns to lower values by the next breeding season due to underground recharge. Breeding in Tule Valley occurs earlier than in other Bonneville locations because of the warm-water sources. Spatial and temporal distribution of the spotted frog since the regression of Lake Bonneville 15,000 years ago and threats to present habitats are discussed.     

Variation in the life history and abundance of three popluations of Bruneau hot springsnails ( Pyrgulopsis bruneauensis )

Bruneau hot springsnail density, size class structure, recruitment, and mortality were measured monthly over approximately 2 years and compared to environmental variables at 3 hot spring sites in southwestern Idaho. Food resources (attached algae) and water chemistry were similar among sites, but temperature, population density, and size structure differed significantly. Density was highest at a warm, fairly constant temperature site. A cooler, highly variable temperature site and a site where temperatures frequently approached or exceeded thermal maxima tolerance limits had lower densities. Size class structure varied seasonally and distinctly among sites, with recruitment occurring year-round at temperatures < 36°C. Mortality affected different size classes at different sites, with smaller snails incurring greatest mortality at site 3 (highest temperature variability). Growth rates were positively correlated with temperatures up to 36° C. Mean snail size differed among sites and also appeared to be related to temperature, with the variable temperature sites having larger snails. Although these snail populations are found in a range of water temperatures, they appear best adapted to springs with mean temperatures between 32° and 33°C and low thermal variance.     

Studies on Alenophalera bronneomixia (Lepidoptera: Notodontidae)—a pest of the West African indigo plant,Lonchocarpus cyanescens (Papilionaceae)

Summary

This paper is concerned with the general biology of the notodontid moth, A. bronneomixia whose larvae are found to be serious defoliators of the West African indigo plant, Lonchocarpus cyanescens.

At temperatures fluctuating between 21°C and 29°C (mean 22·5°C) and humidities between 70 to 95 per cent eggs developed and hatched in a mean of 11·1 days from deposition, mean hatch being 93 per cent.

Under the said environmental conditions, the life cycle from egg to adult entailed six larval instars and a prepupal stage before the real pupa, all lasting 60 to 80 days. Larvae were strongly monophagous, fed communally and in nature pupated in soil/litter very close to the foot of their invaded food plant.

Adults were retiring and in the field deposited clusters of numerous eggs preferably on the abaxial surfaces of their food plants. In nature, this moth's population seemed strongly regulated by high egg and larval parasitization, larval predation and fungal attacks at the pupal stage.     

Density and biomass of redband trout relative to stream shading and temperature in southwestern Idaho

Density and biomass of redband trout ( Oncorhynchus mykiss gairdneri ) relative to stream temperature were examined in headwater reaches of Big Jacks and Little Jacks Creeks in southwestern Idaho. Stream shading was greater (mean of 80% versus 46%) and solar insolation was lower (mean of 7.9 versus 15.1 mJ · m -2 · day -1 ) in Little Jacks Creek ( P P ≤ 0.07) but increased more rapidly and to higher levels (24° - 26° C) in Big Jacks Creek. Daily maximum water temperatures (23 km downstream of headwater springs) during July 1996 were lower in Little Jacks Creek (ranged from 18° to 22° C) than in Big Jacks Creek (20.2° to 26° C, P P -2 and 25.0 g · m -2 ) compared to Big Jacks Creek (0.3 fish · m -2 and 8.9 g · m -2 , P = 0.01). Trout density was negatively correlated with increases in water temperature ( P = 0.03) and solar insolation ( P = 0.09) in both streams. Trout biomass increased with stream shading and was negatively correlated with solar insolation ( P < 0.1). Warmer water temperatures in Big Jacks Creek were likely due to historical summerlong livestock grazing, which drastically reduced riparian shading.     

Optimal temperatures for growth and upper thermal tolerance of juvenile northern leatherside chub

We examined optimal temperatures for growth and the upper thermal tolerance of juvenile northern leatherside chub ( Lepidomeda copei ). We conducted 2 experiments using the acclimated chronic-exposure method to estimate optimal temperature for growth of age-0 northern leatherside chub (range 12.8–28.3 °C). Upper thermal tolerance was estimated using the critical thermal maximum (CTM) and upper incipient lethal temperature (UILT) methods for fish acclimated at 15, 18, 23, and 28 °C. We also measured stream temperatures in Yellow Creek, Summit County, Utah, during July–August 2006 to compare our results to actual summer stream temperatures. Survival in growth tests was not significantly different between treatment temperatures in either experiment (P > 0.098). The optimal temperature for growth in the 1st trial estimated from the 2nd-order polynomial regression was 23.0 °C, falling outside the range of experimental temperatures (12.8–22.2 °C). The estimated optimal temperature for growth in the 2nd trial was 23.2 °C. In the upper thermal tolerance tests, juvenile northern leatherside chub had CTM values between 29.6 and 35.0 °C; CTM values increased as acclimation temperature increased. Upper incipient lethal temperatures (LT50) ranged from 26.5 to 30.2 °C, increasing with acclimation temperature. Summer stream temperatures in Yellow Creek had a lower mean (14.0–18.1 °C) than did the optimal temperature for growth determined in these studies, but these temperatures exhibited diel fluctuations as large as 15.7 °C.     

Effects of temperature on the embryonic development and hatchling size of Betaeus emarginatus (Decapoda: Caridea: Alpheidae)

Betaeus emarginatus is an alpheid shrimp inhabiting rock pool environments characterized by strong fluctuations of ambient factors. Here we describe the embryonic development of B. emarginatus, and analyse the effects of three different temperatures (13, 15 and 20°C) on the duration of the incubation period, egg volume, and the size and morphology of newly hatched larvae. The sequence of embryonic development followed the general patterns described for decapods. Temperature affected the duration of the incubation period, which varied between 66.8 days (13°C) and 22.7 days (20°C). Independent of the thermal regime, eye pigment appeared after completing approximately 50% of the incubation time. Despite almost an identical initial egg volume in all three treatments, there was an inverse relation between temperature and final volume: eggs incubated at 13°C were substantially bigger (471.5 mm³) than those maintained at 15 (403.3 mm³) and 20°C (387.6 mm³). The size of the hatchlings increased significantly with decreasing incubation temperature. However, morphological variability of selected larval characters was generally higher at elevated temperatures. We compare the results obtained with those reported for other decapods inhabiting temperate waters, and discuss the question of why larvae of B. emarginatus incubated at higher temperatures hatch at a smaller size compared to those incubated at lower temperatures.     

Stream temperatures and the elevational distribution of redband trout in southwestern Idaho

During July to September 1994-1995, I examined water temperatures at the lower end of the elevational distribution of redband trout ( Oncorhynchus mykiss gairdneri ) in 4 streams in the Owyhee Mountains in southwestern Idaho. Maximum water temperatures in Castle, Shoofly, Little Jacks, and Big Jacks creeks during low flows during a drought in 1994 ranged from 26.7° C to 29.0° C. Water temperatures fluctuated 9.5-11° C during the 24-h period maximum temperatures were observed. Stream flows at the lower end of Big Jacks and Little Jacks creeks in 1994 were 3 s -1 and subsided underground 50-130 m downstream pools inhabited by trout. Trout were distributed to lower elevations where drainage basin area was larger in 2 of 3 yr ( P 5 km downstream of the lowest pool inhabited by trout in 1995-1996.     

Distribution, movements, and habitat use of razorback sucker ( Xyrauchen texanus ) in a lower Colorado River reservoir, Arizona-Nevada

Distribution, movements, and habitat use of 10 wild adult razorback suckers ( Xyrauchen texanus ) were examined in Lake Mohave, Arizona-Nevada, from November 1994 through July 1997. Movement rates (0.00-17.35 km d -1 ) and ranges ( x = 39 km) were similar to those for riverine populations. All study fish returned to spawning sites used in previous years, but they also visited other spawning areas. Spawning females were significantly ( P = 0.031) more active than males (480 vs. 87 m d -1 ) and moved substantial distances between spawning sites during peak reproduction (1-28 February). Fish became most active (m d -1 , km month -1 ) after spawning and moved to areas known to support higher algal production. Fish were typically within 50 m ( P 30.0 m). Adults were detected throughout the available thermal gradient (12°-30°C), but during summer typically had body temperatures between 18° and 22°C. Vertical movements within the water column showed no correlation with depth or time of day, but seasonal shifts suggest fish may regulate body temperature by seeking specific temperatures during reservoir stratification.     

Effect of salinity on seed germination of Triglochin maritima under various temperature regimes

Triglochin maritima L. (arrow grass), an herbaceous perennial in the family Juncaginacea, is widely distributed in inland and coastal salt marshes of North America. Triglochin maritima seeds from a population growing in a salt marsh at Faust, Utah, were germinated at 4 temperature regimes (12-h night/12-h day, 5-15° C, 10-20° C, and 15-25° C) and 5 salinities (0, 100, 200, 300, 400, and 500 mol m -3 NaCl) to determine optimal conditions for germination and level of salt tolerance. Ungerminated seeds were returned to distilled water after 20 d to determine whether seeds could recover from salinity treatments. Maximum germination occurred in distilled water, and increases in NaCl concentration progressively inhibited seed germination. No seeds germinated at concentrations higher than 400 mol m -3 NaCl. A temperature regime of low night (5° C) and high day (25° C) temperature yielded maximum germination; all other temperature regimes significantly inhibited seed germination relative to this optimum. Recovery of germination was highest at 5-25° C and lowest at 5-15° C. Recovery of seed germination when seeds were transferred to distilled water from salt solutions was highest at 5-25° C (72%) for seeds exposed to the 500 mol m -3 NaCl pretreatment and significantly reduced at other temperature regimes. The recovery germination response indicates a synergistic inhibitory interaction effect on germination when seeds were exposed to high salinities at suboptimal thermoperiods.     

Temperature and high salinity effects in germinating dimorphic seeds of Atriplex rosea

Atriplex rosea L. (Chenopodiaceae; tumbling orach), an annual herb, is a widely established weedy species of disturbed sites in all counties of Utah. Seeds of Atriplex rosea were collected from a salt marsh in Faust, Utah, and are dimorphic, light brown, and 2-2.5 mm wide, or black and 1-2 mm wide. Seed germination responses of the black and brown seeds were studied over a range of salinity and temperature. Both brown and black seeds germinated at 1000 mM NaCl, and the optimal temperature for germination of both types was 20°-30°C. Variation in temperature, however, affected germination of black seeds more than brown seeds. At lower thermoperiod only 40%-50% black seeds germinated in nonsaline control, and germination was almost completely inhibited with the inclusion of salinity. However, all brown seeds germinated in control at temperatures above 5°-15°C, and inhibition caused by salinity was comparatively lower. Brown seeds had a higher germination rate than black seeds at all temperature and salinity treatments. The highest rate of germination of both seeds occurred at the temperature regime of 5°-15°C. Recovery of germination for black seeds when transferred to distilled water after being in various salinity treatments for 20 days was quite variable. Recovery decreased with increase in salinity at lower temperature regimes, increased with salinity at optimal thermoperiod, and had no effect at 20°-30°C. Brown seeds recovered poorly from salinity at all thermoperiods except 5°-15°C, where recovery decreased with an increase in salinity. Brown seeds are adapted to germination in the early part of the growing season, whereas black seeds are capable of surviving harsher conditions and can germinate in later time periods. Characteristics of the dimorphic seeds increase chances for survival in the harsh saline desert environment.     

LXX.—New or little-known Tipulidæ (Diptera).—XXXIX. Australasian species

Summary

Evaporative cooling, through moistening of the eyes, panting, urinating and salivating, takes place in the spurred tortoise at high ambient temperatures. The mean temperature at which thermoregulatory salivation is initiated (39·5° ± 0·4°C) is constant, irrespective of body size, but the rate of panting is slower in heavier tortoises. Very small tortoises, however, do not pant for more than a few seconds.

Tortoises are inactive at 13°C and their body temperatures do not vary from the ambient. At 21° and 26°C, heat loss through transpiration exceeds metabolic heat production: at 33°C body temperatures are higher than the ambient. Increased range and variability at higher temperatures may be explained by the fact that spurred tortoises hold their breaths for long periods—a mechanism that could serve to reduce respiratory water loss. When breathing is actually taking place, however, the rate of respiration depends on body temperature: this grades into panting above 35°C.     

Effect of temperature on brood relocation in Pogonomyrmex salinus (Hymenopteria: Formicidae)

Brood movement in response to temperature by Pogonomyrmex salinus (seed-harvester ant) nurse workers was examined in the sagebrush steppe of southeast Idaho. Shading the mound surface of P. salinus colonies at dawn caused a decrease in mound temperature and led to significantly less brood accumulation near the surface. In a related experiment, a lab colony of P. salinus was offered an artificial thermal gradient during the cool/dark portion of the daily cycle. Nurse workers removed brood from the 21° --22° C range to soils with temperatures between 29° C and 36° C. Daily brood relocation by P. salinus nurse workers is a highly flexible behavior, capable of immediate response to temperature, and does not appear to follow a strict endogenous rhythm.     

Effects of temperature on the survival and growth of age-0 least chub ( Iotichthys phlegethontis )

Larval and juvenile stages of many fishes require nursery habitats that provide optimal conditions for growth. Loss or degradation of these habitats limits recruitment, causing population and species declines. Least chub ( Iotichthys phlegethontis ), an endemic cyprinid in the Bonneville Basin, is currently restricted to a few spring complexes in Utah. This species utilizes the warm shallow spring margins as spawning and rearing habitat throughout the summer. This study was conducted to determine effects of temperature on survival and growth of age-0 least chub to understand the importance of temperature in selection of spring margins as rearing habitat. Age-0 least chub were exposed to 5 temperatures (14°C, 17°C, 21°C, 24°C, and 27°C) for 112 days. Growth rates varied significantly with temperature except at 17°C and 27°C, and growth rates were highest at 21°C ( P < 0.001). Maximum growth rate for age-0 least chub, estimated from a 2nd-order polynomial regression, would occur at 22.3°C. These thermal requirements indicate the importance of warm rearing habitats in producing strong year classes and viable populations. However, warm spring margins also enable western mosquitofish, a nonnative competitor and predator of least chub, to thrive in these spring habitats. Broad thermal limits of the least chub suggest that it could persist at cooler temperatures, which would reduce the viability of western mosquitofish populations.     

Effects of water temperature on growth of razorback sucker larvae

I conducted laboratory experiments and fit a response surface regression model to evaluate growth of endangered razorback sucker ( Xyrauchen texanus ) up to 37 days post-hatch. Fish growth at ad libitum ration was positively related to water temperature, and larvae reared at 25.5°C grew about twice as fast in length and 4 times as fast in weight as those at 16.5°C. Growth was intermediate at 19.5°C and 22.5°C. Time required for razorback sucker larvae to exceed 25 mm total length (TL), a potentially important threshold for reduced predation, was 30 days (post-hatch) at 25.5°C, 33 days at 22.5°C, 36 days at 19.5°C, and 41 days at 16.5°C. Time to exceed 25 mm TL increased to 52 days under a low growth rate of 0.29 mm ? d –1 . Faster growth rates could reduce the time that razorback sucker larvae are vulnerable to predation by abundant and co-occurring small-bodied fish and invertebrate predators in nursery areas. Growth of razorback sucker larvae could be enhanced if flow re-regulation at Flaming Gorge Dam and downstream levee removal restored connections between the Green River and its floodplain and increased availability of warm and productive wetlands.     

Emergence of adult pandora moths in Arizona

Adult pandora moths began emerging in late July, and peak daily emergence occurred during 10&ndash;15 August. The mean density of moths emerging per 929 cm 2 of ground surface ranged from 0.1 to 2.4. The ratio of emerging males to females varied from 3&ndash;4:1 during the initial days of emergence to 1:1.5 during the last 10 days of August. Postemergence behavior is described and discussed in relation to egg mass deposition and species survival. &nbsp;&nbsp;&nbsp;     

How survival and food intake of tri-spine horseshoe crabs,Tachypleus tridentatus respond to thermal variation: implications for understanding its distribution limit

ABSTRACT

Temperature appears to have pervasive effects on larval development, feeding and movement patterns of tri-spine horseshoe crabs, Tachypleus tridentatus. To investigate how temperature determines their geographic distribution range, we examined the survival rate (SR), survival time (ST) and food intake of subadult T. tridentatus under different temperature levels in a seven-day experiment, followed by a three-day recovery to room temperature at 25°C. Significantly lower SR and ST of subadults were found at 40°C after the end of the seven-day experiment. Meanwhile, SR and ST of individuals at 0°C were negatively affected when the temperature was brought back to 25°C. Mean food intake of the subadults was statistically lower at 0–20°C and 35–40°C compared to that at 25°C and 30°C. After the subsequent three-day recovery to 25°C, only the individuals previously exposed to 15°C and 20°C had recovered to their normal level of feeding activities, but not the other treatment groups. These findings may provide preliminary data on how thermal tolerance determines the present distribution of T. tridentatus, which are found in large numbers around Beibu Gulf (annual temperature variation: 22–30°C), while considerably lower population densities are observed in the colder southern Sea of Japan and warmer seas of Southeast Asia.     

Respiration characteristics differ among cheatgrass ( Bromus tectorum L.) populations

Cheatgrass ( Bromus tectorum L.) is a dominant weed that has increased the frequency of wildfire in the Great Basin since its introduction about 100 yr ago. This study examines characteristics of respiratory metabolism in several different populations. Seeds from 6 populations were germinated and metabolic heat rates (q) and dark respiration rates (R co2 ) of all seedlings were measured calorimetrically at 15° and 25° C or (for 3 populations) at 5° intervals from 5° to 35° C. Growth rates, substrate carbon conversion efficiencies, and Arrhenius temperature coefficients were calculated from the data. Results show that cheatgrass metabolism is most efficient at temperatures near 0° C; at temperatures above 20-25° C, efficiency goes to zero. Cheatgrass populations differ in their temperature dependencies of substrate carbon conversion efficiency and predicted growth rate. Measurements of respiratory heat and CO 2 rates as functions of temperature can be made relatively quickly and used to aid understanding of metabolic adaptation by invasive and native species to the environment.