Warm Refuge Research Articles

Unsheltered Rainbows: Meaning of Home among Homeless and Runaway Sexual Minority

Home is a warm refuge for many individuals; however, some were not gifted and became unsheltered. Various sociopolitical factors include multiple layers of oppression, mental health, and unsatisfactory relationship scaffold rootlessness. The study aimed to explore the meanings of home among seven gay homeless and runaways. They were recruited through homogenous purposive and snowball sampling. It charted the track of interpretative phenomenological qualitative research and employed photovoice, a visual methodology. Participants were 18 and above self-identified gay men who had experienced youth homelessness for over a year. Framework analysis and triangulation were employed for the interpretation and validation. For the results, the cohort’s meanings of home are forming a non-normative family (nourishing emotional connection with significant non-relatives and achievement of heteronormative goal), characteristics of a home (physical qualities and experiential qualities), positive and emotional environment, emblem of achievement, and genuine parental acceptance. Findings suggest that birth-home and homelessness experiences contribute to conceptualizing and characterizing home as a physical structure and experience. Thus, diversity and inclusivity are social issues that need to be highlighted.

Understanding summertime thermal refuge use by adult Atlantic salmon using remote sensing, river temperature monitoring, and acoustic telemetry

Adult Atlantic salmon (Salmo salar) return to natal rivers several months before spawning and during summer can be subjected to temperatures that exceed their upper temperature tolerance limits. Salmon use thermal refuges to minimize exposure to high temperatures, but little information exists regarding behavioral thermoregulation by adult Atlantic salmon. We examined behavioral thermoregulation by Atlantic salmon during summer in-river residence in a Quebec river with a novel combination of thermal infrared remote sensing, river temperature monitoring, and acoustic telemetry. Adults engaged in behavioural thermoregulation at cooler ambient river temperatures (17–19 °C) than previously recorded for this species and maintained body temperature within a narrow range (16–20 °C) via use of cool and warm refuges. Adults used large, stable, stratified pools as refuges, allowing multiple individuals to thermoregulate simultaneously without leaving the pool. Low river discharge and high temperatures can be physical barriers to salmon migration, preventing them from accessing suitable refuges (e.g., pools). Identifying and maintaining connectivity to thermal refuges may be critical for persistence of Atlantic salmon populations as climate changes and rivers warm.

Recent invader or indicator of environmental change? A phylogenetic and ecological study of Cylindrospermopsis raciborskii in New Zealand

Cylindrospermopsis raciborskii is a diazotrophic and potentially toxic cyanobacterium that was initially thought to be confined to tropical freshwaters. Recently it appears to have expanded its range to more temperate regions of the globe. There are contrasting hypotheses to explain this spread including; dispersal of highly adapted strains or localised spread from warm refuges as climatic or environmental conditions change. C. raciborskii was first detected in the isolated island nation of New Zealand in 2003, providing a unique opportunity to explore whether this recent identification is due to a new incursion or resultant from climatic or environmental change. Phylogenetic analysis (nifH, ITS1-L, ITS1-S, and rpoC1) of six strains isolated from two New Zealand lakes showed they were most closely related to those from South America, and suggest that the recent detection of this species was not due to a new incursion. Ten years of environmental data from three lakes (Waaki, Waikare and Whangape) experiencing blooms were analysed to identify potential reasons for recent C. raciborskii blooms. This analysis showed that the relatively recent (within the last 20–30 years) collapses of extensive macrophyte stands in lakes Waaki, Waikare and Whangape have resulted in increased turbidity’, low water column dissolved reactive phosphorus and seasonal shifts in the dissolved inorganic nitrogen availability, all conditions known to facilitate C. raciborskii dominance. Collectively these data indicate that C. raciborskii has always been present in New Zealand, and that recent changes in environmental conditions in these lakes are now facilitating bloom events.

Thermal Cost of Refuge Use Affects Refuge Entry and Hiding Time by Striped Plateau Lizards Sceloporus virgatus

Abstract Escaping prey decide whether to enter and how long to stay in refuges. According to refuge-use theory, hiding time increases as costs of emerging increase and costs of staying in refuge decrease. We studied effects of air temperature on probability of entering refuges and the effects of thermal cost on hiding time (duration in refuge). Few striped plateau lizards (Sceloporus virgatus) used refuges at intermediate air temperatures, but most readily entered cool refuges at the lowest air temperatures and relatively warm refuges at higher temperatures. Because running speed in lizards decreases as body temperature decreases, S. virgatus that are cool upon morning emergence presumably reduced their probability of being captured by entering refuges. As air and presumably body temperatures increase, refuges are initially cooler than outside, contributing to infrequent use. At higher, but not thermally stressful, temperatures, a greater probability of using refuges may reflect lower thermal costs in ref...

Faunal turnover and changing oceanography: Late Palaeozoic warm-to-cool water carbonates, Sverdrup Basin, Canadian Arctic Archipelago

Carbonate sedimentary rocks in the Fosheim–Hamilton sub-basin at the eastern end of the Sverdrup Basin contain a particularly sensitive record of changing palaeoceanography and faunal turnover during the northward movement of Pangaea through the Late Palaeozoic. Carboniferous and earliest Permian inner ramp carbonates are a photozoan association of colonial corals, fusulinids, algae and ooids, with sparse heterozoan elements (crinoids, brachiopods and bryozoans). Based on modern analogues these biotic components reflect warm-water oligotrophic marine environments. Contemporaneous mid-ramp and basin biotas are dominated by a heterozoan fauna (solitary corals, crinoids, bryozoans and brachiopods) that grew in cooler deeper waters that may have been beneath a thermocline. Initial cooling began in the latest Sakmarian with an influx of cool deep water and climatic deterioration allowing cool and warm waters to mix, disrupting the thermocline, and producing a sub-tropical marine biota whose remains were reworked by storms and re-deposited as tempestites. Faunas are heterozoan (crinoids, bryozoans, brachiopods and sponges) with photozoan elements (colonial corals and symbiont bearing fusulinids) prominent only in inner ramp facies. By late Artinskian these photozoan components are only present in shallowest basin-margin environments. Artinskian subtropical waters contained somewhat elevated trophic resources that together with mixing of photozoan and heterozoan elements in the subtropical inner ramp produced the greatest faunal diversity seen in the Sverdrup Basin. The biota was completely boreal in nature, and warm shallow waters with a warm refuge biota, were now supplemented by cool waters derived from the Panthalassa Ocean. Profound change took place in the Kungurian, coincident with localised uplift during the Melville Disturbance and increased siliciclastic input. Neritic, storm-dominated sediments are wholly heterozoan (brachiopods, bryozoans, crinoids and sponges) with no remaining photozoan elements. Nutrient levels are elevated (but not eutrophic) as indicated by phosphate and glauconite, extensive bioerosion, numerous infaunal foraminifers, and an impressive and diverse shelly biota, that during times of high siliciclastic input was replaced by a profuse Zoophycos infauna. Brachiopod and bryozoan faunas are distinctly boreal. Continued cooling, relatively high nutrients, as indicated by abundant glauconite and phosphate, and decreased siliciclastic input eventually resulted in an abundant heterozoan biota (brachiopods, bryozoans, crinoids and sponges) with local gigantism, but reduced brachiopod and bryozoan diversity. These Middle Permian rocks may be the coolest water deposits in the Sverdrup Basin. The faunas are still part of a boreal Arctic province, with strong ties to cool water faunas of Uralian basin. The succession ends with Late Permian biosiliceous spiculitic cherts containing accessory heterozoan components (brachiopods, bryozoans and few crinoids). These sediments, in part coeval with evaporites and terrestrial red beds on the Eastern European Platform, are interpreted to reflect a combination of cool waters, elevated nutrients, and mid-latitude storminess.

Genetic Diversity ofCylindrospermopsisStrains (Cyanobacteria) Isolated from Four Continents

The genetic diversity of Cylindrospermopsis strains (cyanobacteria) was examined using mainly the 16S-23S internally transcribed spacer (ITS1) sequences. Strains were grouped in three clusters: (i) America, (ii) Europe, and (iii) Africa and Australia. These results suggested a recent spread of Cylindrospermopsis across the American and European continents from restricted warm refuge areas instead of exchanges between continents. On the other hand, they also suggested a recent colonization of Australia by African strains.

Trade-offs in the choice of refuges by common wall lizards: do thermal costs affect preferences for predator-free refuges?

Prey often respond to predator presence by increasing refuge use. However, some types of refuges may expose prey to other types of predators. In addition, in selecting refuges ectothermic animals may have a conflict between safety and thermal suitability. In this paper we examined in the laboratory whether common wall lizards, Podarcis muralis (Laurenti, 1768), (i) prefer to use warm refuges to cold ones, (ii) prefer safe refuges to those with chemical cues of a saurophagous snake, and (iii) whether lizards face a trade-off between using a warm but snake-scented refuge or a cold but odorless one. Results did not show differences in refuge use in relation to refuge temperature, because common wall lizards only entered to investigate it, but they were not forced to hide. So, common wall lizards did not have to be at suboptimal temperatures for longer times. Common wall lizards avoided the use of predator-scented refuges, regardless of thermal conditions, and they also increased their movement rate, trying to escape from the terrarium. Because snakes are inconspicuous inside refuges, an avoidance response to their chemicals may enhance the survival possibilities of common wall lizards. We conclude that in common wall lizards, predation-risk costs are more important than thermal costs in determining refuge use.

Emotion and phylogeny.

Gentle handling of mammals (rats, mice) and lizards (Iguana), but not of frogs (Rana) and fish (Carassius), elevated the set-point for body temperature (i.e., produced an emotional fever) achieved only behaviorally in lizards. Heart rate, another detector of emotion in mammals, was also accelerated by gentle handling, from ca. 70 beats/min to ca. 110 beats/min in lizards. This tachycardia faded in about 10 min. The same handling did not significantly modify the frogs' heart rates. The absence of emotional tachycardia in frogs and its presence in lizards (as well as in mammals), together with the emotional fever exhibited by mammals and reptiles, but not by frogs or fish, would suggest that emotion emerged in the evolutionary lineage between amphibians and reptiles. Such a conclusion would imply that reptiles possess consciousness with its characteristic affective dimension, pleasure. The role of sensory pleasure in decision making was therefore verified in iguanas placed in a motivational conflict. To be able to reach a bait (lettuce), the iguanas had to leave a warm refuge, provided with standard food, and venture into a cold environment. The results showed that lettuce was not necessary to the iguanas and that they traded off the palatability of the bait against the disadvantage of the cold. Thus, the behavior of the iguanas was likely to be produced, as it is in humans, through the maximization of sensory pleasure. Altogether, these results may indicate that the first elements of mental experience emerged between amphibians and reptiles.

Behavior of Juvenile Lizards (Iguana iguana) in a Conflict between Temperature Regulation and Palatable Food

Juvenile green iguanas were placed in a situation of conflict between two motivations: a thermoregulatory drive and the attraction of a palatable bait. To be able to reach the bait (lettuce), they had to leave a warm refuge, provided with standard food, and venture into a cold environment. In experiment 1 the time interval between sessions with bait, ranging from 1 to 8 days, had no effect on the duration of stay on the bait. This result shows that the lettuce was not a necessary food, deprivation of which would have had to be compensated for. In experiment 2 as the ambient temperature at the bait decreased the lizards spent less time feeding on lettuce, and they visited the bait less frequently. This result shows that the lizards traded off the palatability of the bait with the disadvantage of the cold. These findings support the hypothesis that a common currency makes it possible for lizards to compare two sensory modalities.

Floristic biodiversity and history of African arid regions

The phytochorological patterns of the arid flora of Africa are discussed on various levels. The arid regions of the African continent are linked by a large number of taxa with disjunct distribution. Analysis of these disjunct patterns supports the hypothesis of fragmentation of a once continuous arid belt running from the Namib desert region to the Western Sahara via East Africa. The flora of the arid regions of Southern Africa shows regular patterns, e.g. identical fragmentation of distribution areas of several taxa on an infrafamilial or infrageneric level, allowing formulation of a hypothesis concerning the sequence of differentiation steps during formation of the floras. Very interesting patterns can be attributed to effects of the last glaciation. For example, disjunct distribution patterns in the Namib region can be interpreted as a result of survival of palaeotropical taxa in warm refuge areas during the last glaciation.

Lack of caloric regulation in rats during short-term feeding

Rats were trained to feed 2 h daily. Each rat was presented during three 10-day-long alimentary periods with each of the following diets: control (C), low calorie (L), and high calorie (H). The food was placed at an ambient temperature of -15 degrees C at 16 m from a warm refuge. It was found that the rats ingested similar amounts of food, regardless of energy density of the diet, and therefore did not compensate for variations in the caloric density of a diet. This was despite the recognition of a novel diet on the first day of its presentation as manifested by a change in rats' meal pattern. L diet was eaten slowly, suggesting that it was less palatable than the C or H diets. The results suggest that the rat placed in a closed economy with only short-term access to food imposed by a hostile environment does not adjust its food intake in accordance with energy value of the food. Its momentary food intake appears to be controlled by the gustatory properties of the food.

Influence of food and water deprivation on the behavior of the white rat foraging in a hostile environment

Rats were trained to feed 2 hr per day, the food offered being placed at 16 m from a warm refuge and the ambient temperature being −15°C. They were food deprived for 0, 12, 22, 46, 70 and 94 hr prior to the six feeding sessions. Speed of feeding and meal duration were not influenced by food deprivation. The amount eaten, the number of meals, the time spent at the feeder, the speed of running to the feeder and the number of foraging rats increased from 0 hr fast to 22 hr then plateaued for the 46, 70 and 96 hr fasts. The same experiment was carried out after water deprivation for 0, 12, 22, 46 and 70 hr. Rats could find, at −15°C, water kept at 30–40°C and at 16 m from their warm refuge. The speed of running to water and the rate of drinking were not influenced by water deprivation. The amount drunk, drinking-bout duration, the number of drinking-bouts, total drinking time and the number of rats drinking increased monotonically from 0 to 70 hr deprivation. Two main conclusions are drawn from these data: (1) in the rat, up to 70 hr deprivation, the motivation to feed seems to be stronger than the motivation to drink; (2) to satisfy hunger or thirst, the nervous system uses several different motor subsystems of behavior.

Strategies Adopted by Juvenile Lizards Foraging in a Cold Environment

Juvenile Tupinambis teguixin were placed in a conflicting situation: feeding vs. cold environment. To feed they had to leave a warm refuge (Top 44–45 C) and go 1.5 m to where food was presented at an ambient temperature (Ta) varying from 25 to 0 C. When Ta was decreased, the lizards managed to eat a constant amount of food by modifying their behavior. They shortened the duration and increased the number of the meals, returning to the warm refuge between meals. In the cold, they left the food when their cloacal temperature dropped to about 32 C. After satiation, they maintained their cloacal temperature behaviorally between 34 and 38 C. The attempt to increase the lizards' drive for food by increasing the length of the fast preceding the access to food from I to 17 days did not result in any behavioral change during feeding. The only modification was a decrease in the amount eaten when the fast was shorter than 3 days. In a warm environment, when the intervals between feeding increased from I to 17 days, the lizards' main response was not an increase in food intake but, rather, a decrease in the growth rate and sloughing frequency.

Interfaces of steam electric power plants with aquatic ecosystems.

Growth and reproduction may be stimulated by increased temperature in the cooling system and thermal plume during seasons when ambient water temperature is less than optimum, but growth, reproduction and survival are reduced when the elevated temperatures become excessive. Some fish species congregate in the warm thermal plumes during cold seasons but are excluded from this living space by temperatures above their preference in the summer. However, the warm refuge provided by a thermal plume in cold seasons can be a death trap if a power plant shuts down suddenly and exposes the fish to cold shock exceeding their lower thermal tolerance limits. The factors that tend to affect different segments of the biota are discussed.