Aim: To examine the reaction of extreme preterm infants with regarding to body temperature and transepidermal water loss during skin-to-skin care according to Kangaroo Mother Care (KMC) during the infant’s first week of life. Method: This was a descriptive quantitatively designed study, which was a pilot study within the framework of a larger project. Nine children, with a median gestational age of 24.91 weeks, were examined by measuring body temperature (axilla and skin temperature) as well as transepidermal water loss before, during and after KMC. Results: The study showed that skin temperature tended to rise during KMC, especially for those children who were nursed with KMC for more than 60 minutes. Eight out of nine children had, after completing KMC, a normal axilla temperature. As was expected, transepidermal water loss was elevated when measured both pre and post test. Despite this, the children showed normal body temperature. Conclusion: The results of the study support that KMC can create a micro-climate that, for at least one hour, makes it possible for even extreme preterm infants to maintain a body temperature within the normal range during their first week of life.

Our aim was to understand mechanisms responsible for excessive electrolyte loss in the sweat gland and the potential impact on fluid balance during exercise in heat stress conditions. Human physiological testing under exercise/heat stress and immunofluorescence staining of sweat glands from skin biopsies were compared between healthy individuals (with normal and high sweat sodium chloride concentration, [NaCl]) and with cystic fibrosis patients (CF), who exhibit excessively salty sweat due to a defect of Cl- channel cystic fibrosis transmembrane conductance regulator (CFTR). Three novel findings are presented. First, excessively salty sweat may be associated with reduced expression of CFTR in the sweat gland reabsorptive duct of healthy individuals in addition to in those with CF; however, although a link to a CF gene mutation in healthy individuals with high sweat [NaCl] was not demonstrated, the possibility of an undetected CFTR mutation or polymorphism remains to be investigated as an underlying mechanism. Two, CF and healthy individuals with excessively salty sweat respond to moderate dehydration (3% body weight loss during exercise) with an attenuated rise in serum osmolality, greater relative loss in plasma volume, but similar perceived thirst compared to healthy individuals with "normal" sweat [NaCl]. However, individuals with CF respond to rehydration with hypotonic beverage by drinking less ad libitum in response to reduced serum [NaCl], suggesting that thirst-guided fluid replacement may be more appropriate for this population rather than restoring 100% of sweat loss following dehydration as is often recommended in healthy individuals.

Ice hockey is a contact sport played in a cold environment which leads to assumptions that players are not exposed to a thermal challenge. The purpose of this study was to test the hypothesis that the wearing of hockey protective equipment during an exercise protocol designed to simulate a hockey game would induce a thermal challenge and lead to decrements in performance. In order to test this hypothesis and qualify the physiological responses, subjects performed a standardized protocol performed on a stationary cycle ergometer in an environmental chamber set at typical (12ºC) ice hockey ambient conditions. The simulation was performed twice; once while wearing cotton undergarments only (NP), and once while wearing cotton undergarments and the typical protective equipment worn during a hockey game (P). Work intensity during each trial was held constant and was evaluated by examining mean power output, which was similar under both P and NP conditions (348.2 W vs 352.08 W, P > 0.05) P vs NP, respectively. Body (37.18 ºC vs 36.58 ºC) and skin temperatures (34.12 ºC vs 28.85 ºC) were elevated in P vs NP, respectively (P<0.05). Core temperatures (37.50 ºC vs 37.41ºC) displayed a trend towards being higher in P vs NP particularly during the third period of simulation (P = 0.053). Sweat loss as a percent of body mass was greater in P vs NP (2.57% vs 1.18%, respectively P<0.05), which led to an increase in plasma osmolality (287 vs 283 mosmol/kg H2O, respectively P<0.05) working heart rate (83.7% vs 78.8% of maximum heart rate), resting heart rate (63.4% and 55.9% of maximum heart rate), and urine specific gravity (1.026 vs 1.017) for P vs NP respectively (each P<0.05). The drop-off in power from pre to post simulated game was examined in both conditions by the use of five repeated maximal six second sprints interspersed with 24 seconds of recovery. The drop-off in both peak (12.0% vs 0.2%) and mean power (14.5% vs 2.7%) was greater in P versus NP (P<0.05). Plasma lactate concentration was higher following the simulated game in P vs NP (9.64 vs 5.96 mmol/L, P<0.05) as was plasma norepinephrine (2274.0 vs 1366.9 pg/ml, P<0.05). Rating of Perceived Exertion increased by 30-53% in the P condition (P<0.05) even though power outputs were equivalent. The elevated body temperature and increased water loss appeared to increase glycolytic flux, which when coupled with the consequences of thermal stress, reduced power output and led to the perception of elevated work intensities during the simulated game.

Thermoregulatory patterns, the use of rest-phase heterothermy, the energetic significance of clustering behaviour, and the role of sunning behaviour in thermoregulation were assessed in the white-backed mousebird Colius colius, an southern African arid zone species. I hypothesised that C. colius makes significant rest-phase energy savings by means of clustering behaviour, and has the ability to reduce diurnal energy costs by utilising solar radiation. I tested these hypotheses using indirect calorimetry and surgically implanted temperature-sensitive telemeters, and by simulating solar radiation in a constant-environment chamber. Rest-phase body temperature (T[b]s) was highly labile, with rest-phase T[b]s of down to 26 °C being recorded. During the rest-phase, T[b] was not regulated with respect to a setpoint temperature, as typically occurs in endotherms. Rather, rest-phase T[b] patterns were characterised by periods of linear decreases (passive cooling) at a rate dependent on ambient temperature and the number of individuals in a group. I did not observe any instances of torpor, as described in the literature. When T[b] depression did occur, it appeared to be the result of passive heat loss, and not the metabolic down-regulation which typically precedes a torpor bout. These findings, together with the phylogenetic position of the Coliidae, raise questions regarding the evolution of torpor. The inability of individual mousebirds to maintain a rest-phase setpoint T[b] suggests that in C. colius the physiological mechanism responsible for the defence of a rest-phase setpoint T[b] is replaced by a behavioural mechanism, namely clustering behaviour. The birds in this study showed a basal metabolic rate 40% below the predicted allometric values, and a circadian amplitude of body temperature (T[b]) of 5.2°C, 195% of the predicted value. The use of linear independent contrasts revealed that these deviations from the expected allometric values are not due to the phylogenetic relationships of the Coliiformes, and hence are likely to represent adaptation. These conservative metabolic traits offer opportunities for significant energy savings and are presumed to be adaptive in the unpredictable habitat of this species. The birds were able to make significant energy savings by means of huddling behaviour. At an ambient temperature of 15°C, the energy expenditure of birds in a group of six was 50% of that of single birds. The energy savings the birds were able to make were dependent on ambient temperature and the number of birds in the group. The ability to lower energy requirements by means of huddling behaviour is likely to be highly adaptive when dealing with low nocturnal temperatures in an environment where food supplies are spatially and temporally unpredictable. When allowed access to simulated solar radiation, individual mousebirds showed 15 - 30% reductions in their energy expenditure, while maintaining a constant body temperature. These reductions in energy expenditure hence represent thermoregulatory savings. My results support the hypothesis that solar radiation may be important in the energy budgets of some bird species. The ability to reduce food requirements by means of absorbing solar radiation is likely to be strongly selected for in the arid areas inhabited by C. colius, which are characterised by large circadian fluctuations in ambient temperature, in addition to resource unpredictability. Thermoregulation in C. colius appears to involve an interaction of behavioural patterns and physiological traits. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1998.

This study identified gender-related differences in post-exercise peripheral blood flow and body temperature in neutral environment (21ºC). The subjects were 11 male (22 +/- 4 years) and 14 pre-ovulatory female (23 +/- 3 years) recreational runners VO2max: 62 +/- 5 mL/kg &bull; min for men and 55 +/- 5 mL/kg &bull; min for women). Forearm blood flow rectal (Trec) and forearm skin temperatures (Tsk), and forearm vascular resistance (mean arterial pressure/forearm blood flow) were measured pre-exercise (pre), immediately after (t = 0), and every 15 minutes up to 105 minutes (t = 105) post-exercise (45-minute run at 75% of VO2max). ANOVA revealed main gender effects for Trec, Tsk, and forearm blood flow (men > women) as well as for forearm vascular resistance (women > men). Compared to pre-exercise, Trec at t = 0 showed a similar increase in men (1.3ºC) and women (1.2ºC). Trec decreased thereafter to reach pre-exercise level after 25 minutes in men. In women, Trec kept decreasing to reach a lower than pre-exercise level after 60 minutes (p < 0.05). Tsk was similar at pre and t = 0 for both genders. In contrast, Tsk was lower in women than men (29.0 +/- 1.3 versus 30.7 +/- 1.5ºC) at t = 105 (p < 0.05). Forearm vascular resistance was similar in men and women pre-exercise and decreased by about 50% in both groups at t = 0. Between t = 30 and t = 105, the women increased their forearm vascular resistance up to 35% more than did the men. These observations suggest the existence of gender-related differences in thermoregulatory and cutaneous blood flow responses during recovery from submaximal exercise.

Recent evidence suggests that avian facultative hypothermic responses are more common than previously thought. Traditionally, several categories of avian hypothermic responses have been recognized, and are frequently differentiated on the basis of minimum body temperature (T[b]) The available data suggest that the capacity for shallow hypothermia (rest-phase hypothermia) occurs throughout the avian phylogeny, but that the capacity for pronounced hypothermia (torpor) is restricted to certain taxa. However, there are currently too few data to test hypotheses concerning the evolution of avian hypothermic responses. Facultative hypothermia occurs over most of the avian body mass (M[b]) range, but is most common in small species. Minimum body temperature during hypothermia (T[min]) is continuously distributed from 4.3 °C to ca. 38°C. The continuous T[min] distribution, as well as recent evidence that the T[b] ranges of different avian physiological states may overlap, question the biological reality of specific T[b] limits. Pattens of thermoregulation during avian hypothermic responses are relatively variable, and do not necessarily follow the entry-maintenance-arousal patterns that characterize mammalian responses. Avian hypothermic responses are determined by a suite of ecological and physiological determinants. I investigated normothermic thermoregulation and hypothermic responses to restricted food in the speckled mousebird Colius striatus in the context of the distinction between normothermia, rest-phase hypothermia, and torpor. The lowest T[b] recorded in a bird which was able to arouse spontaneously was 18.2°C. However, I was unable to clearly discern between normothermic, hypothermic and torpor T[b] ranges. Furthermore, hypothermic responses did not accord with the patterns typically observed in birds and mammals. Metabolic suppression normally associated with entry into torpor and the defence of a torpor T[b] setpoint was largely absent. Laboratory data for C. striatus, as well as published data for Colius colius suggest that clustering behavior plays an important thermoregulatory role in mousebirds. Hence, I investigated thermoregulation under semi-natural conditions in C. striatus. In particular, I was interested in the interaction between clustering behavior and hypothermic responses during energy stress (restricted feeding). In contrast to clustering birds, rest-phase thermoregulation in single birds was characterised by linear decreases in T[b] and the birds did not appear to defend a specific T[b] setpoint. During restricted feeding, both clustering and single birds exhibited significant decreases in rest-phase T[b]. The extent of these facultative hypothermic responses was greater in single birds than in clustering birds, supporting the prediction that clustering behavior moderates the use of facultative hypothermia. I also tested the prediction that in free-ranging C. colius, the use of heterothermy should be rare, even at the coldest time of the year. I recorded mid-winter rest-phase body temperatures (T[b]) in a flock of free-ranging C. colius in an arid habitat in the Karoo, South Africa. The mousebirds' rest-phase T[b] was fairly labile, but was maintained above 33°C, despite T[a]s as low as -3.4 °C. The mousebirds showed no evidence of torpor under natural conditions; a facultative hypothermic response, during which T[b] was reduced to 29 - 33°C, was only observed on one occasion. The observed patterns of thermoregulation supported my predictions, and suggest that thermoregulation in clustering C. colius in the wild is significantly different to that of single birds under laboratory conditions. My results also suggest that the pronounced capacity for heterothermy usually associated with mousebirds is not necessarily representative of their patterns of thermoregulation under natural conditions. The capacity for avian torpor appears to be dependent on phylogeny. To investigate phylogenetic constraints on the capacity for torpor, I measured metabolic responses to food deprivation in a small, arid-zone passerine, the red-headed finch (Amadina erythrocephala). I observed significant reductions in rest-phase energy expenditure and body temperature (T[b]) in response to restricted feeding. The maximum extent of T[b] suppression (ca. 5°C) and energy savings (ca. 10%) were consistent with those reported for a number of other passerines. The lowest T[b] I observed in a bird able to arouse spontaneously was 34.8°C. My data support the hypothesis that the capacity for heterothermy in passerines is phylogenetically constrained, and that the majority cannot employ torpor in response to energetic stress. Selection for the capacity for torpor is presumably similar to the selection pressures acting on other avian energetic traits, such as basal metabolic rate (BMR). I tested the generality of a recent model linking the slow-fast mammalian metabolic continuum to global patterns of climatic predictability using BMR data for 219 non-migratory bird species. Avian BMR varied significantly between zoogeographical zones, with Afrotropical, Indomalayan and Australasian species generally exhibiting lower BMR than Holarctic species. In addition, the magnitude of differences between arid and mesic species varied between zones. In the Nearctic, these differences were pronounced, whereas no significant differences were evident for Afrotropical or Australasian species. A slow-fast metabolic continuum similar to that described in mammals appears to exist for birds, with higher BMR associated with predictable, seasonal environments and lower BMR with less predictable environments, in particular those affected by the El Niño Southern Oscillation. I constructed a generalised, conceptual model which attempts to predict the occurrence of torpor using phylogeny, M[b] constraints, a trade-off between energetic benefits and potential ecological costs, and specific ecological factors. A recent hypothesis suggests that endotherm heterothermy is monophyletic, and predicts that torpor should be more widespread in phylogenetically older taxa. Once phylogeny is considered, the most important determinant of avian torpor is M[b]. I used an existing model of endotherm torpor to predict the relationship between M[b] and minimum T[b] during torpor. The available data show that the lower limit of torpor T[b] is determined by the M[b]-dependent costs of rewarming following a torpor bout. Finally, I constructed a model based on the assumption that torpor is adaptive if the energetic benefits exceed the potential ecological costs. The model predicted that torpor should be more prevalent in species near the extremes of the avian metabolic continuum. The available data provide tentative support for this prediction. In addition to generalised factors such as phylogeny and M[b], specific aspects of a particular species' ecology need to be considered when predicting the occurrence of avian torpor. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2001.

Endothermy in birds and mammals is invariably associated with homeothermy. However, homeothermy can only be maintained if sufficient energy is obtained to meet the animals' maintenance budget. In mammals, daily torpor and hibernation have evolved to conserve energy when energy inputs from the environment are insufficient to meet maintenance requirements. Several studies have suggested that daily torpor and hibernation do not represent distinct physiological responses but are components of a continuum of heterothermy. Under laboratory conditions, even within phylogenetically ancient eutherian mammals, such as elephant shrews, it is unclear whether daily torpor or hibernation is used. Furthermore, an interpretation of the torpor patterns observed under laboratory conditions is complicated by the fact that torpor patterns often differ between laboratory and free-ranging conditions. Within the more recent mammal lineages, torpor has been observed in strepsirrhine primates. The occurrence of torpor in strepsirrhines is interesting as it pertains to arguments relating to the colonization of Madagascar by strepsirrhine primates as well as implications for human physiology. The first aim of this study was to investigate and quantify parameters that characterize torpor in a phylogenetically ancient eutherian mammal (Macroscelidae: Elephantulus myurus) under free-ranging conditions. This was done mainly to resolve whether daily torpor and hibernation were physiologically discrete responses. The second aim was to investigate torpor occurrence in a more recently evolved eutherian mammal (Primates: Galago moholi). The objective was to gain insights into the phylogenetic distribution of torpor and to provide a physiological verification of torpor occurrence in a mainland strepsirrhine relative to arguments about the colonization of Madagascar. I measured body temperatures in three monthly cycles between May 2001 - May 2002 in 22 free-ranging E. myurus. I recorded a total of 467 torpor bouts throughout the study period. The elephant shrews were capable of daily torpor throughout the year, with torpor most prevalent during winter and correlated with ambient temperature, photoperiod and invertebrate abundance. Only two torpor bouts were observed during summer. I suggest that although torpor use was most prevalent during winter, summer torpor might also be important for energy conservation in this species during drought years. This highlights the need for long-term physiological data in free-ranging animals. The mean torpor Tbmin and the mean bout length for the whole year were in the range expected for daily heterotherms. However, there was some marginal overlap with hibernation characteristics; a few torpor bouts were longer than 24 hrs in duration indicating that the animals were capable of opportunistically extending torpor bouts longer than 24 hours in response to unpredictable energetic shortfalls. Tbmin also decreased below 10°C. However, a consideration of behavioural and ecological factors argues against hibernation in E. myurus. Instead, these results support the idea of a physiological continuum for heterothermy. A return to normothermic body temperatures requires considerable energy expenditure, and this is perceived to be one of the major disadvantages of torpor. E. myurus offset the high cost of arousal from low body temperatures by using exogenous passive heating. This is achieved by coupling of the timing of arousal with ambient temperature cycles. Laboratory studies that quantify torpor energetics are usually conducted under constant temperature conditions and are likely to underestimate the energetic benefits accrued through the use of ambient temperature cycles during arousal. Torpor is often displayed during the animal's rest phase. However, nocturnal small mammals that utilize passive heating to assist arousal from torpor may enter torpor during the nighttime, thus effectively advancing the onset of the rest phase. I investigated the functional significance of daily and seasonal rhythms of body temperature in normothermic and torpid free-ranging E. myurus. Daily patterns of Tb, in normothermic E. myurus suggested polyphasic Tb patterns that nevertheless indicated a rest phase coincident with the daytime. I suggested that the principal benefit of a flexible daily rhythm of Tb, is that it facilitated torpor use during the nighttime and arousal by passive exogenous heating using ambient temperature cycles. It has been suggested that the evolution of endothermy precluded the need for homeothermic mammals to be sensitive to Ta cycles because they could maintain physiological function despite fluctuations in the ambient temperature. Elephant shrews utilize passive heating and provide excellent models with which to investigate whether mammals can entrain their body temperature rhythms to ambient temperature cycles. I experimentally tested whether food restricted E. myurus can entrain torpor cycles to shifts in the Ta cycle while holding the light-dark cycle constant. Food restriction and short photoperiod were only sufficient to induce torpor in E. myurus if photoperiod and Ta, cycles are in phase with each other. Shifting the cold T, into the photophase prevented the expression of torpor. I concluded that the body temperature rhythm is most probably tightly coupled with the photoperiod cycle and that although Ta and photoperiod usually act synergistically in nature, photoperiod is probably the stronger zeitgeber. The evolution of endothermy is thought to have been facilitated by the advent of endothermic energy sources such as brown adipose tissue (BAT), the principal site of nonshivering thermogenesis (NST). Rock elephant shrews are amongst the smallest members of the Afrotheria, the most basal of the eutherian lineage. I determined whether the phylogenetic placement of E. myurus and reliance on passive heating might result in a decreased capacity for NST relative to other eutherians. I investigated the capacity for NST in winter acclimated E. myurus by measuring the thermogenic response to noradrenalin (NA) injection. I used phylogenetically independent analyses to compare E. myurus NST capacity with other eutherians. E. myurus had an NST capacity that was no different from other eutherian mammals. Although they displayed a NST capacity that was 74% of that expected on the basis of body mass, this value was not significantly different from phylogenetically independent allometric predictions. Although heterothermy is almost always considered in the context of how the environment affects function , its use may offer insights into topics such as island biogeography and species dispersal. For example, there have been suggestions that heterothermy might have played an important role in the successful colonization of Madagascar by strepsirrhine primates. To my knowledge no studies exist as yet that provide a physiological verification of this suggestion. Currently no data exist on thermoregulation and heterothermy in any free-ranging African strepsirrhines. The lesser bushbaby, Galago moholi, is a small nocturnal strepsirrhine primate that experiences severe winters and drastic food reduction during winter and is a candidate employer of torpor. I measured body temperatures of 11 free-ranging lesser bushbabies, Galago moholi, captured at different times between February 2002 - September 2003. I did not record any incidents of heterothermy throughout the study period. Why does G. moholi not employ heterothermy? I consider several alternatives; phylogenetic placement, physiological and ecological factors that might preclude the use of torpor in this species. I suggest that the breeding pattern observed in G. moholi obviates torpor use whilst increasing fecundity, which would be adaptive if the animals are confronted with high predation risks. Much is currently known about the advantages of torpor use. This study highlights the need to consider and investigate those physiological, ecological and phylogenetic factors that might constrain species from utilizinq heterothermy. Furthermore, this study highlights the potential for thermoregulatory studies to offer insights into topics as widely separated as evolution of endothermy to species dispersal and island biogeography. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

Chapter 2: Avian frugivores have been somewhat poorly studied with regards to the effects that different fruit sugar types and concentrations have on their digestive efficiencies. Digestion of sugars in equicaloric and equimolar artificial fruit of different sugar types at varying concentrations and molarities were therefore investigated in two relatively large South African frugivores, the Knysna (Tauraco corythaix) and the Purple-crested (Gallirex porphyreolophus) Turaco. Artificial fruits of 6.6, 12.4 and 22% sucrose and glucose respectively and artificial fruits of 0.42, 0.83 and 1.66 mol L-1 sucrose and glucose respectively were used to determine daily food and energy intake, digestive efficiencies and digestive transit times. Digestive transit times of both Turaco species were slower with an increase in sugar concentration and molarity, irrespective of sugar type. Food intake of both Turaco species increased with decreasing concentration and molarity, irrespective of sugar type suggesting compensatory mechanisms for energy requirements. Apparent assimilation efficiencies of both Turaco species ranged from 61.4-90.0% and 60.2-92.4% for equicaloric and equimolar artificial fruit diets respectively. Consequently these two frugivores appear to be tolerant of sugar type and would be expected to select fruits based on energy yields. Future studies of the composition of indigenous forest fruit sugars may give insight into food preferences of the Turaco species and their role as potential seed dispersers of fruiting tree species. Chapter 3: The effects that different fruit sugar types and concentrations have on food preferences of avian frugivores have been relatively poorly studied. Although it has been recently advocated that preference is based on equicaloric energy it is also important to note whether preferences change as energy content changes. Therefore, sugar preferences of equicaloric and equimolar artificial fruit of different sugar types at varying concentrations and molarities were investigated in two relatively large South African frugivores, Knysna (Tauraco corythaix) and Purple-crested (Gallirex porphyreolophus) Turacos. Artificial fruits of 6.6, 12.4 and 22% sucrose and glucose respectively and artificial fruits of 0.42, 0.83 and 1.66 mol L-1 sucrose and glucose respectively were used to determine sugar preferences. Knysna Turacos preferred the sucrose to the glucose equicaloric artificial fruit diet at low concentrations whereas Purple-crested Turacos showed no preference for either diet. Both Turacos species preferred the sucrose equimolar artificial fruit diet to the glucose at low concentrations. At high concentrations neither species showed a preference for either equicaloric or equimolar artificial fruit diets. This suggests that energy requirements influence food preferences more than sugar type and that birds will select fruit that is higher in energy irrespective of sugar type. This complements an earlier study on digestion of sugars at varying concentrations of differing equicaloric and equimolar artificial fruit sugar types. It again emphasizes the need for future studies looking at the composition of indigenous forest fruit sugars in order to obtain insight into the role of these avian frugivores as potential seed dispersers of fruiting tree species. Chapter 4: Avian frugivores may select fruit based on their seed loads and pulp to seed ratios and this may have important implications for their role as seed dispersal agents. Consequently the effect of different seed packaging was investigated in two relatively large South African frugivores, Knysna (Tauraco corythaix) and Purple-crested (Gallirex porphyreolophus) Turacos. Small-seeded artificial fruits containing on average five black plastic beads (2.24 mm diameter) and large-seeded artificial fruits containing one average one single black plastic bead (3.85 mm diameter) were used to investigate transit rates and food preference. Total seed volume in the two fruits was on average approximately equal (29.42 mm3 and 29.88 mm3 for small- and large-seeded fruits, respectively). Bead transit rates ranged from 38-45 min for Knysna Turacos and 36-50 min for Purple-crested Turacos with faster transit rates on the small-seeded diet. Pulp transit rates ranged from 25-39 min for Purple-crested Turacos and 34-40 min for Knysna Turacos. Purple-crested Turacos had significantly shorter pulp transit rates on the large-seeded than the small-seeded diet whereas Knysna Turacos had no significant difference between diets. Knysna Turacos preferred the small-seeded to the large-seeded artificial fruits whereas Purple-crested Turacos showed no preference for either diet. Further studies on avian dispersers will contribute to a greater understanding of their evolutionary relationship with fruiting plants. In particular, future studies establishing suitable seed sizes and volumes for use in determining the effect of seed packaging on larger birds are required as well as studies looking at seed packaging of indigenous forest fruit and the effects of seed packaging on digestion and food preference in indigenous avian frugivores may give insight into the role of avian frugivores as fruit consumers and seed dispersers. Chapter 5: Fleshy-fruited plants and frugivores share a mutualistic relationship with plants offering the frugivores a reward of fleshy fruit pulp in order to disperse their seeds. In return frugivores receive a food source and consequently a source of energy. However all fruits are not equal in terms of available energy and consequently the digestion efficiency of six indigenous tree species was investigated in an avian frugivore, the Knysna Turaco (Tauraco corythaix). It was predicted that the Turacos would process these indigenous fruits efficiently and have fast transit rates and high intake rates irrespective of species. Fruits were fed to the Turacos in separate trials to determine daily food and energy intake, digestive efficiencies and digestive transit times. Digestive transit times of Knysna Turacos (c. 12-28 min) fall within the range of published examples for other frugivorous birds. Apparent assimilation efficiencies of the Turacos ranged from c. 15-84% and were generally lower than those observed in other avian frugivores. Future studies looking at the nutritional composition of indigenous forest fruit may provide insight into the Knysna Turacos digestive efficiency and consequently their food preferences and role as potential seed dispersers of fruiting tree species. Chapter 6: Seed dispersal plays an important role in the persistence, regeneration and maintenance of plant communities. It is therefore not surprising that much attention has been paid to the germination potential of seeds ingested by frugivorous animals. Consequently the aim of this study was to determine what effect ingestion of seeds by Knysna Turacos (Tauraco corythaix) has on the germination rate and germination percentage of indigenous South African tree species. Fruits from twelve tree species were fed to the Turacos in separate trials and seed retention times were determined as it has been suggested that a longer seed retention time may increase germination rates. At the end of each trial, seeds were extracted from excreta of individual birds and planted in trays containing potting soil. Germination was recorded daily until 14 days post of no germination. Knysna Turacos seed retention times were in the range of those obtained by other studies with Ficus sur seeds having the fastest retention times (12.4 ± 0.8 min) and Celtis africana the slowest (34.6 ± 5.6 min). Mean percentage germination of ingested seeds was not significantly different to pulp removed and whole fruit seeds indicating that ingestion by Knysna Turacos did not enhance percentage germination through either seed coat abrasion or pulp removal. Seed ingestion by Knysna Turacos did not influence the rate at which seeds germinated in 75 % of the tree species while it did for ingested F. lutea, F. natalensis and F. sur seeds which germinated significantly sooner than whole fruit seeds. Future studies relating the composition of indigenous forest fruits to food preferences of Knysna Turacos may give insight into their role as potential seed dispersers of indigenous fruiting tree species. Chapter 7: Frugivorous animals play a major role in dispersing tropical, and to a lesser extent, temperate tree species. In order to attract potential seed dispersers, plants generally offer a reward of fleshy fruit pulp. Criteria for fruit choice by avian frugivores are influenced by a number of non-nutritive (e.g. fruit size and colour) factors; and nutritional composition of the fruit. There is a paucity of nutritional composition and other fruit trait data of indigenous South African fruit. This information is necessary in order to determine which frugivores are likely to ingest which fruits and consequently act as potential seed dispersal agents. This information would provide us with an understanding of the inter-relationships between indigenous fruit and frugivores in South Africa. Consequently nutritional composition was investigated in various indigenous fruit species that avian frugivores feed on. Fruits were collected from 38 indigenous tree species found in KwaZulu-Natal afromontane and coastal forests. Pulp was freeze-dried to constant mass and then analyzed for sugar, lipid and protein content; and for water content determination. Fruit width in this study ranged from 4 mm (Searsia rehmanniana and Trema orientalis) to 40 mm (Annona senegalensis, Ficus sur and Xylotheca kraussiana). Of the fruits examined in this study 29% were black and 43% red when ripe. Most (84%) fruit species analysed for sugar content were hexose dominant with 50% being fructose and 34% being glucose dominant. Only 16% of the fruit species analysed were sucrose dominant. Fruits in this study were generally observed to be high (mean: 68.1 ± 3.3%; n = 30) in water content; and low in protein and lipid content respectively (mean: 8.2 ± 0.5%; 9.3 ± 2.2%; n = 30) indicating that these fruits species could be considered as nutrient-dilute. Future studies need to determine the nutritional composition of the remaining indigenous South Africa fruit in order to develop a comprehensive database as well as examining non-nutritive factors. Together this information would play a key role in understanding fruit preferences and consequently seed dispersal and would therefore be useful in developing management plans for forest conservation. Chapter 8: Many seasonal thermoregulation studies have been conducted on Holarctic birds that live in predictable, highly seasonal climates with severe winters. However, relatively few studies have been conducted on their southern hemisphere Afrotropical counterparts that encounter less predictable climates with milder winters. These latter birds are expected to conserve energy in winter by down-regulating their metabolic rates. Therefore in this study, metabolic rate was measured during summer and winter in Knysna Turaco, Tauraco corythaix (Musophagiformes, Musophagidae) (c. 310 g), a non-passerine, in order to test whether there is energy conservation in winter. No overall significant differences in resting metabolic rates over a range of ambient temperatures were observed between winter and summer. However, whole-organism basal metabolic rates were 18.5 % higher (p = 0.005) in winter than in summer (210.83 ± 15.97 vs. 186.70 ± 10.52 O2 h-1). Knysna Turacos had broad thermoneutral zones ranging from 20-28 oC in winter and 10-30 oC in summer. These results suggest that Knysna Turacos show seasonal thermoregulatory responses that represent cold defense rather than energy conservation, which is contrary to what was expected. Keywords: sugar digestion, sugar preference, seed packaging, basal metabolic rate (BMR), resting metabolic rate (RMR), phenotypic flexibility, indigenous fruit, germination percentage, germination rate, fruit sugars, protein, lipids, fruit size, fruit colour, Knysna Turaco, Purple-crested Turaco. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

Tyrimo objektas: miego ir paros ciklo įtaka atminčiai, sveikiems asmenims. Darbo tikslas: nustatyti kaip miegas ir paros ciklas veikia sveikų žmonių atmintį. Darbo uždaviniai: 1. Išsiaiškinti, kaip vidinės kūno temperatūros pokyčiai veikia nuotaiką ir mieguistumą. 2. Ištirti, kaip paros ciklo metu kinta atminties aktyvumas. 3. Palyginti atminties aktyvumą po išsimiegotos nakties su atminties aktyvumu po bemiegės nakties. Tyrimo hipotezės: vidinės kūno temperatūros svyravimai atspindi atminties aktyvumą. Tyrimo metodai: Mokslinės literatūros analizė. Empirinis tyrimas naudojat kompiuterinę testų programą ANAM4. Statistinė duomenų analizė. Išvados: 1. Vidinė kūno temperatūra veikia, mieguistumą ir nuotaiką. Kai nakties metu vidinė kūno temperatūra krenta, padidėja mieguistumas ir pablogėja nuotaika, o kai dienos metu vidinė kūno temperatūra kyla, mažėja mieguistumas ir pagerėja nuotaika. 2. Vidinės kūno temperatūros svyravimai atspindi darbinės atminties aktyvumo svyravimus, kai reikia atsiminti išmoktus objektus. O atliekant matematinius skaičiavimus ir erdvinio suvokimo užduotis, atmintis aktyvumo svyravimai nesutapo su vidinės kūno temperatūros svyravimais. 3. Atmintis aktyvumas yra geresnis dieną po išsimiegotos nakties, lyginant su diena po bemiegės nakties. / The object of research: sleep and circadian rhythm effects on healthy people memory. The aim of research: to find out how sleep and circadian rhythm effects memory in healthy The goals of research: 1. Find out, how core body temperature effects mood and sleepiness. 2. Determine, how memory activity changes in circadian rhythm. 3. Compare memory activity after sleep night with memory activity after sleepless. Hypothesis: core body temperature reflects fluctuations in memory activity. Research methods: Scientific literature analysis. Empiric research using computer cognitive tests program ANAM4. Statistical data analysis. Conclusions: 1. Core body temperature affects sleepiness and mood. When at night time core body temperature decreases, sleepiness increase and mood impairs, and when at day time core body temperature increases, sleepiness decreases and mood improves. 2. Core body temperature fluctuations reflects memory activity, when need to recognize learned objects. In mathematical computation and spatial processing, memory activity does not match with core body temperature fluctuations. 3. Memory activity is higher during day after sleep night, comparing with memory activity after sleepless night.

Southern toads (Anaxyrus terrestris) are ectothermic terrestrial amphibians. As such they are sensitive to thermal and hydric variability. The interactive effect of hydration state and body temperature is not well understood. The aim of this study is to determine if the costs of dehydration vary at different temperatures and if so, whether toads will select different temperatures to minimize these costs. Costs of dehydration were evaluated by measuring metabolic rate at 100% and 85% hydration state, at 30 and 20 oC. Temperature selection of toads at 100% and 85% hydration state was measured using a thermal gradient. Body temperature, but not hydration state, was determined to have a significant effect on metabolic rate. No significant difference in temperature selection was found between toads at 100% and 85% hydration state. Thus, thermoregulatory behavior as influenced by hydration state could not be predicted in Anaxyrus terrestris.