Tenebrionid beetles in the shortgrass prairie: daily and seasonal patterns of activity and temperature

ABSTRACT. 1. Patterns of daily and seasonal activity for seven species of tenebrionid beetles, genus Eleodes , were investigated in the shortgrass prairie of northeastern Colorado. The relationship between time of activity, body temperatures, and rates of water loss of the beetles was examined in the field and in laboratory experiments.
2. Common species were active from April until the end of October; however, asynchronous peaks of abundance occurred.
3. Beetles were diurnally active with peaks of daily activity occurring 2–4 h after sunrise and before sunset. Less than a 2 h shift in mean time of activity occurred between seasons.
4. Within species, body temperatures measured in the field closely corresponded to temperatures selected in an experimental thermal gradient; hence, species seemed to prefer particular body temperatures and were most active during times when those temperatures could be achieved. Body temperatures measured in the field approximated ambient temperatures measured in the vicinity of the beetle.
5. Significant differences among several species were found for times of daily activity and corresponding body temperatures.
6. Ability to resist water loss by evaporation was not correlated with daily or seasonal activity patterns.     

Changes in Escherichia coli O157:H7 numbers during holding on excised lean, fascia and fat beef surfaces at different temperatures

Aim:  To investigate changes in Escherichia coli O157:H7 numbers on excised beef carcass surfaces over 72 h at different temperatures.
Methods and Results:  Excised lean meat, fascia and fat were inoculated with E. coli O157:H7 and held in an environmental chamber for 72 h, at air speed 0·5 m s⁻¹, relative humidity (RH) 90%, and temperatures 4, 8 and 12°C. On lean, pathogen counts increased significantly at 12°C. On fascia, significant reductions in counts occurred at 4 and 8°C. Pathogen numbers were significantly reduced on fat at 4, 8 and 12°C (64 h). Counts on fat were significantly less at all temperatures, compared to lean or fascia and surface water activity, a_w, decreased significantly over time on fat at 4°C. Significant decreases in surface pH values were recorded on all meat substrates.
Conclusions:  The survival of E. coli O157:H7 varied in relation to the meat substrate and the holding temperature. Reductions in counts on fat surfaces appeared to be related to low surface a_w values. No relationship between pathogen survival and surface pH was established.
Significance and Impact of the Study:  The use of excised meat pieces in an environmental cabinet offers a more flexible approach to determining the use of different chilling regimes in the production of safe meat.     

Swarming behaviour in the Australian beetle, Heteronyx obesus, with notes on related species

Abstract. (1) Heteronyx obesus swarmed about twice annually on evenings when relative humidity was > 80% and temperature was at or above 20°C at 19.30 hours local time.
(2) Swarms were characterized by the frenzied, random flight of their component insects, and the clustering of males about females on vertical structures.
(3) Early the following morning beetles searched for pasture containing favoured food plants, and then burrowed into the soil near them.
(4) Adults did not ingest food before, during or for several days after swarming; the oesophagus and crop of all insects dissected was distended with gas, probably air. This condition appeared to be associated with pre-flight behaviour of individuals.
(5) The post-swarm activity was concerned with feeding, dispersal, maturation of eggs and oviposition.
(6) The distribution of individuals of the next generation was strongly influenced by presence in the sward of favoured food (sorrel, Rumex species) of the adults.     

Bimodal life cycle of the burying beetle Nicrophorus quadripunctatus in relation to its summer reproductive diapause

Abstract 1. Under natural conditions in Kyoto, Japan, the reproductive activities of Nicrophorus quadripunctatus Kraatz (Coleoptera: Silphidae) decreased in summer and the species showed a bimodal life cycle.
2. In the laboratory, most adult pairs raised at 20 °C under a LD 12:12 h regime reproduced when provided with a piece of chicken. In adults raised at 20 °C under a LD 16:8 h regime, however, both reproductive behaviour and ovarian development were reduced. It is concluded that these adults entered a reproductive summer diapause.
3. High temperature (25 °C) also suppressed the reproductive behaviour even under a favourable LD 12:12 h regime. In the field, therefore, adults reduce their reproductive activity in summer because of diapause induced by long-day photoperiods and direct inhibition of reproduction by high temperatures.
4. When the temperature was changed from 20 °C to 25 °C immediately after hatching of larvae, they reached the wandering stage in 95% of adult pairs. When the temperature was changed from 20 °C to 25 °C immediately after oviposition, however, no larvae hatched in 85% of pairs. Egg mortality was significantly higher at 25 °C than at 20 and 22.5 °C; no eggs hatched at 27.5 °C. The physiological mechanisms for reducing reproduction probably prevent the beetles from inefficient oviposition in summer.     

Laboratory studies of egg development and diapause in Isoperla obscura (Plecoptera) from a mountain stream in Norway

SUMMARY 1. A laboratory study of egg development of the stonefly Isoperla obscura (Zetterstedt) collected from the stream Flybekken (southern Norway, 61°25'N, 8°48'E, 1373 m a.s.l.) showed a short diapause followed by a prolonged period of postdiapause quiescence.
2. Diapause occurred over a wide range of temperatures (−20°C to +8°C), but 0–1°C was the most favourable for fast diapause development and successful hatching. Diapause development required temperatures below 12°C, but sub-zero diapause temperatures increased mortality during the postdiapause phase, as well as reducing hatching success.
3. The threshold for initiation of postdiapausal development was about 1–2°C. Development rate increased and variation in development time decreased at higher water temperatures. These may be important characteristics to ensure seasonal and geographical synchrony of development in individual populations. Low postdiapausal temperatures were unfavourable, despite a subsequent increase in water temperature. No response to postdiapausal photoperiod was detected.
4. The results agreed well with conditions noted in the natural environment, and with the abundance of this species at high altitudes and latitudes in Fennoscandia. Nevertheless, Isoperla obscura also occurs in streams in the maritime parts of western Norway. The results of the present study suggest that egg development in these populations will prove to be different.     

Thermoregulatory trade-offs result from vegetation removal by a harvester ant

Abstract.  1. Analyses of ecological trade-offs help to explain how organisms balance competing demands. Harvester ants ( Pogonomyrmex occidentalis ), are conspicuous residents of shortgrass prairie in western North America; worker P. occidentalis actively clear all vegetation from the immediate vicinity of their large gravel mounds. This study is based on the prediction that vegetation clearing yields a thermal trade-off by increasing soil temperatures; during cool periods the resulting increase in soil temperature opens new time windows for activity, while during hot periods the soil temperature is more likely to exceed the maximum thermal tolerance for this species. To test the hypothesis that daily and seasonal trade-offs in ant activity result from vegetation removal, the effects of experimentally applied shade on activity patterns were measured.
2. Harvester ant activity correlated highly with ground temperature; experimental shading of ant mounds shifted daily activity patterns by lowering ground temperature. Shading in the morning significantly delayed the onset of ant activity by preventing solar warming of the mound. In contrast, mid-day experimental shading prevented elevation of ground temperatures to above 50 °C and allowed ants to remain active when lethally high temperatures would normally force them inside the mound.
3. A model derived from field data predicted surface ground temperature (and therefore ant activity) based on air temperature and solar radiation, under conditions of sun and shade. For each of six seasons modelled, shade removal yielded a net gain of activity time. These results indicate that vegetation removal by harvester ants produces an advantageous thermoregulatory effect by helping to maximise activity time.     

Rates of ammonia release from sediments by chironomid larvae

SUMMARY. 1. Microcosms of Lake Balaton mud and sterilized sand and aerated water were used to evaluate ammonia increments in the overlying water as influenced by chironomid density and temperature. In the two approaches, the effects of sediment disturbance and metabolic excretion of chironomids were measured.
2. The activity of larvae increased the ammonia content of the overlying water at temperatures above 10°C. A rise of temperature to 20°C resulted in a 5–20-fold increase in ammonia release in both systems with chironomids.
3. At 10°C combined effects of sediment disturbance and of excretion produced lower release rates than did excretion rates alone (mud-water v. sand-water treatments). At higher temperatures (15 and 20°C) release rates of ammonia by sediment disturbance plus excretion were higher than excretion rates alone. Ammonia excretion contributed significantly to the total release at each temperature.
4. Metabolic mineralization of nitrogen compounds appears to be an important mechanism contributing to nitrogen regeneration from aerobic lake sediments. High N:P ratio (14:1) of chironomid excretion materials supports this interpretation.     

Modelling the time–temperature relationship in cold injury and effect of high-temperature interruptions on survival in a chill-sensitive collembolan

1. Temperature- and time-dependent mortalities were studied and modelled in insects exposed in regimes with constant and alternating temperatures. In these experiments, freezing was not a cause of death.
2. Survival rates at a range of constant low temperatures (– 5 to + 1 °C) and for different exposure periods (1–14 days) were measured in the summer acclimated springtail Orchesella cincta .
3. Daily interruptions of the cold exposure with short intervals at high temperature reduced mortality or slowed the increase of mortality. This effect was stronger at higher temperature (19 vs 5 and 12 °C) and increased with the duration of the interruption (0·25–2 h).
4. The injury was reversible when the cold exposure was limited to 2 days.
5. Survival in desiccated animals (14% water loss) was reduced.
6. It is suggested that the mortality of summer acclimated springtails is caused by a complex metabolic disorder and membrane changes at low temperatures.     

Temperature effects in relation to the patterns of distribution and abundance of three species in the Drosophila affinis subgroup

Abstract. 1. The effect of temperature on several aspects of the biology of Drosophila affinis, D.algonquin and D.athabasca were investigated in order to gain insight as to why these closely related species differ in their spatial and temporal patterns of occurrence.
2. No differences exist between the three species in the effect of temperature on egg hatchability.
3. Productivities of the three species were measured in a temperature gradient device. These measurements indicated that D.athabasca has an advantage in productivity over D.affinis at cooler temperatures (below 25°C). At warmer temperatures (above 25°C) the greater productivity of D.affinis makes it the better species. Drosophila algonquin , like D.athabasca , was characterized by its productivity curve as a species more adapted to cooler climates.
4. The competitive abilities of the three species were measured at 25°C, at 18°C, and in an environment which fluctuated between 18 and 25°C on a daily cycle. Competitive ability was estimated on the basis of the performance of the species in two- and three-species populations.
5. In general, D.affinis exhibited its highest competitive ability relative to the other two species at the highest experimental temperature. D.athabasca had its highest competitive ability at the lowest temperature. The competitive ability of Ddgonquin was intermediate; less than that of D.affinis but greater than D.athabasca .
6. The dependence of competitive ability and productivity on temperature is thought to be partly responsible for the differences between the species with respect to their geographic distributions and their spatial and temporal patterns in natural populations.     

THE EFFECTS OF TEMPERATURE AND HUMIDITY ON THE RATE OF DEVELOPMENT AND THE MORTALITY OF TRIBOLIUM CONFUSUM DUVAL (COLEOPTERA, TENEBRIONIDAE)

The speed of development and the developmental mortality of Tribolium confusum were studied over a series of constant temperatures between 15° and 40° C. at 10, 30, 70 and 90% R.H. using wheatfeed as food.
Eggs did not hatch at 15° or 40° C. at any humidity. At 37.5° C. about 60% of eggs hatched and at all other conditions about 90% hatched. The effect of temperature on the duration of the egg period is shown graphically, the shortest period being at 35° C. Humidity does not affect the egg period.
Larvae failed to develop to pupae at 17.5° C., at 10% R.H. at 20° C, and at 10 and 90% R.H. at 37.5° C. The rate of larval development was affected by both temperature and humidity being quickest at the higher humidities and at about 32.5° C. Larval mortality was less than 16% except at 37.5° C., at 10% R.H. or less, and at 20°C., 90% R.H.
The duration of the pupal period was not affected by humidity and was shortest at 37.5°C. The total developmental period is compared with that of T. castaneum over the range of temperature and humidity conditions in which both species can grow. The optimum for developmental speed and the maximum and the minimum temperatures at which development is possible were all about 2.5°C. lower for T. confusum than for T. castaneum. The developmental periods for the two species were equal at temperatures between 23 and 27°C., depending on humidity. At lower temperatures, T. confusum developed the more quickly and at higher temperatures the more slowly.     

Water temperature in a stream gravel bed and implications for salmonid incubation

SUMMARY. 1. Water temperatures were recorded at hourly intervals in the gravel of a trout spawning area in a small stony stream at depths of 0–20 cm in 1985–86 and 0– 40 cm in 1987.
2. As depth within gravel increased, the size of the daily fluctuations reduced and their time of occurrence was delayed by about 12 min cm⁻¹' in 1985–86 and about 6 min cm⁻¹ in 1987.
3. From October to February mean temperatures at 20 cm depth were, on average, 0.5°C higher than those at the gravel surface. This reflected elevated daily minima more than it reflected elevated daily maxima.
4. From March to July daily minima were lower and daily maxima were higher in the stream than in the gravel. Consequences were: (a) an appreciable increase in mean daily range at all depths in the gravel during the summer, (b) higher daily means (by an average of about 0.4°C) in the water than in the gravel in May to August.
5. Some implications for the early development of salmonid fish are considered.     

Simplified methods of estimating daily mean stream water temperature

SUMMARY. 1. It was assumed that the average of twenty-four hourly temperature readings is the'true'daily mean. For a small stream in upper Tees-dale, northern England, estimates of the daily mean were obtained from: (a) The mean of temperature readings taken at regular but less frequent intervals than hourly (twelve, six and three times per day), (b) The daily mid-point (=¹/₂(maximum + minimum)). (c)Spot temperatures at the two times in the day when the daily temperature trace usually crosses the daily mean value. These estimates were then compared with the'true'mean.
2. The accuracy of the estimate of daily mean decreased with reduced frequency of reading but, even at only three readings per day, was always within ±0.5°C of the true value. Consolidation of the daily estimates gave estimates of monthly and annual means within ±0.1°C of the true values.
3. Nearly 96% of estimates of the daily mean based on the daily midpoint were within ±0.5°C of the true value. The estimates showed a small but statistically significant positive bias.
4. Over 80% of estimates of the daily mean based on the'first mean crossing'were within ±0.5°C of the true value and no bias could be shown.
5. Estimation of daily means from temperature at the time of the 'second mean crossing'was relatively complicated and gave less satisfactory results than did the first mean crossing.
6. The daily mid-point and the temperature at the time of the first mean crossing both gave a good general indication of daily mean temperatures. When consolidated to monthly or annual means the estimates were within ±0.25°C and ±0.10°C, respectively, of the true values.     

Effect of temperature and water activity on in vitro germination of Monilinia spp.

Aims:  This study evaluated the effect of temperature (0–38°C) and water activity ( a _w: 0·87–0·99) on the lag phase prior to germination and the percentage of germination over time for Monilinia laxa , Monilinia fructicola and Monilinia fructigena .
Methods and Results:  More than 80% of viable conidia germinated at 25°C and 0·99 a _w within 2 h for M. fructicola and M. fructigena and 4 h for M. laxa . There was no germination at 38°C, and all three Monilinia spp. germinated at 0°C. At the lowest a _w (0·87), none of the Monilinia spp. was able to germinate at any of the incubation temperatures studied. Whereas at 0·90 a _w, conidia were only able to germinate at 15, 25 and 30°C for the three species studied, except for M. fructicola at 15°C. In contrast, at 0·95, 0·97 and 0·99 a _w, germination occurred at all studied temperatures less 38°C. Generally, the lag phase was longer at low levels of a _w (0·90–095), and differences were more evident as temperatures were far from the optimum (0–5°C).
Conclusions:  Germination and lag phase period were markedly influenced by temperature and a _w, and in general when conditions of temperature and a _w were suboptimal, the lag phase was longer and the percentage of germination was lower.
Significance and Impact of the Study:  Knowledge of the germination requirements of this fungus is important in order to understand their behaviour in natural situations and to provide baseline data required for the construction of new prediction models. Our study might be used to develop a predictive model to understand and control the disease caused by Monilinia spp.     

Intra- and inter-specific variations in egg survival and brood development time for Austrian populations of Gammarus fossarum and G. roeseli (Crustacea: Amphipoda)

SUMMARY. 1. Egg survival (ES, percentage of eggs hatched in vitro ), reproductive success (RS, percentage of live young released from the brood pouch) and brood development lime ( d , days) in four populations of Gammarus fossarum and two populations of Gammarus roeseli were studied, in the laboratory at water temperatures of 2.0–26.1°C. Intraspecific differences between populations were not significant, but interspecific differences were found between the two species.
2. In natural stream populations, the reproductive period of G. fossarum lasted from December to September, that of G. roeseli from March to September.
3. In the experimental temperature range 2–26°C, 73% of the total number (771) of G. fossarum females and 69% of 469 G. roeseli females were ovigerous. Of these, 45% of G. fossarum and 43% of G. roeseli females successfully released live young from their brood pouches.
4. For G. fossarum , the optimum temperatures were 11.4°C for ES, where 76% of the eggs hatched, and 11.8°C for RS, where 77% of the females released live young from their brood pouches. For G. roseli , the optimum temperatures were 13.5°C for ES (51% hatched) and 14.0°C for RS (76% released). Over 50% of eggs hatched at temperatures of 3.6–19.2°C in G. fossarum and at 1 1.9–15.1°C in G. roeseli . Development time increased from 12 days at 21.9°C to 251 days at 2.0°C in G. fossarum , and from 10 days at 24.1°C to 212 days at 4.1°C in G. roeseli .
5. interspecific differences between the effects of water temperature on ES, RS and d are used to explain the different distributional patterns of G. fossarum and G. roeseli in central European running water systems. assuming that other physico-chemical variables are suitable for both species.     

Water temperature and evapotranspiration in surface flow wetlands in hot arid climate

This paper reports data and models for temperatures and energy flows for the Tres Rios surface flow wetlands. Treatment wetlands are solar powered ecosystems, resulting in annually cyclic temperatures. There is also a daily cycle in wetland water temperature of several degrees amplitude. The timing of individual daily measurements may therefore bias the result to values different from the daily mean. The energy balance is dominated by radiation to and from the wetland, heat transfer from air, and evaporative losses. Transpiration causes energy dissipation from the canopy, while evaporation causes energy loss from and cooling of the surface water. Transpiration was found to dominate the water loss. Downstream daily average water temperatures are cooler than daily average air temperatures at all times of the year, due to evaporative cooling. Water cools as it passes from inlet to outlet. The excess sensible heat is dissipated during travel through the inlet region of the wetland. For long detention times, longer than about five days, water temperature reaches a balance condition. Up to that time, sensible heat from the source water also influences evaporation and water temperature. Balance water temperatures ranged from 3.9 °C in winter to 27.2 °C in summer, while mean daily air temperatures ranged from 5.3 to 37.2 °C. Diel variations were found to range up to 6 °C. Stochastic variability produced a band width of ±5 °C. Energy balance models provide a good representation of these phenomena, but are subject to large sensitivity to input variables, especially air temperature, humidity and wind. Evapotranspiration was higher than that predicted for a balance condition, because of the warmth of the incoming water. It was less than that predicted for a grass crop.     

Changes in the ovaries of olive flies (Dacus oleae (Gmelin)) during the summer, and their relationship to temperature, humidity and fruit availability

Abstract. 1. Examination of the ovaries of female olive flies ( Dacus oleae ) from wild populations on Corfu during the summer months of 1975 indicated that all were non-gravid for a period of several weeks during June and July and the terminal follicles were resorbed.
2. Experiments in outdoor cages indicated that olive fruits could stimulate ovarian development during the summer months.
3. Experiments in constant temperature cabinets indicated that high temperatures (i. e. 26–29°C) in conjunction with a low humidity (45 ± 5°%) inhibited ovarian maturation.
4. Whereas the presence of olive fruits offset the effects of temperature and humidity on ovarian development at 26°C in all flies, at 29°C very few were able to mature their ovaries.
5. It is suggested that it is the interaction of temperature, humidity and access to fruit which determine when ovarian maturation ceases and recommences during the summer months.     

Temperature effects on bioconcentration of DDE by Daphnia

1. Lake temperatures vary with season, latitude, elevation and as a result of thermal pollution. In addition, lake temperatures may increase with global warming. Radiotracer experiments were conducted to determine the effects of temperature on the bioaccumulation of lipophilic organic contaminants by zooplankton. Daphnia pulex were exposed to ¹⁴C-labelled DDE, a stable metabolite of the organochlorine pesticide DDT, in particle-free water for 24 h. An increase in temperature from 5 to 25 °C resulted in a 314% increase in bioconcentration factor (the ratio of contaminant concentration in the organism to contaminant concentration in the water).
2. To mimic the fluctuating temperatures experienced by zooplankton during diel vertical migration, we conducted experiments in which animals were exposed to 25 °C for 12 h in the light, then 15 °C for 12 h in the dark. Exposure to this fluctuating temperature regime for 48 h resulted in a 27–33% increase in bioconcentration factor relative to a constant 20 °C control.
3. Live animals accumulated more than twice the amount of DDE than freshly killed animals, indicating that the activity of the organism is important in bioconcentration. This finding sheds light on the possible mechanisms for the increase in bioconcentration at higher constant temperatures. Daphnia pump more water through their branchial chambers at higher temperatures. Thus, if the thoracic limbs are an important site of contaminant uptake, then animals are exposed to more contaminant molecules at higher temperatures. Other possible mechanisms include changes in the thickness of the diffusive boundary layer and changes in cell membrane permeability.     

Temperature effects on bioconcentration of DDE by Daphnia

1. Lake temperatures vary with season, latitude, elevation and as a result of thermal pollution. In addition, lake temperatures may increase with global warming. Radiotracer experiments were conducted to determine the effects of temperature on the bioaccumulation of lipophilic organic contaminants by zooplankton. Daphnia pulex were exposed to ¹⁴C-labelled DDE, a stable metabolite of the organochlorine pesticide DDT, in particle-free water for 24 h. An increase in temperature from 5 to 25 °C resulted in a 314% increase in bioconcentration factor (the ratio of contaminant concentration in the organism to contaminant concentration in the water).
2. To mimic the fluctuating temperatures experienced by zooplankton during diel vertical migration, we conducted experiments in which animals were exposed to 25 °C for 12 h in the light, then 15 °C for 12 h in the dark. Exposure to this fluctuating temperature regime for 48 h resulted in a 27–33% increase in bioconcentration factor relative to a constant 20 °C control.
3. Live animals accumulated more than twice the amount of DDE than freshly killed animals, indicating that the activity of the organism is important in bioconcentration. This finding sheds light on the possible mechanisms for the increase in bioconcentration at higher constant temperatures. Daphnia pump more water through their branchial chambers at higher temperatures. Thus, if the thoracic limbs are an important site of contaminant uptake, then animals are exposed to more contaminant molecules at higher temperatures. Other possible mechanisms include changes in the thickness of the diffusive boundary layer and changes in cell membrane permeability.     

Calling behaviour of the potato aphid Macrosiphum euphorbiae oviparae under laboratory and field conditions

Abstract.  1. The calling behaviour of virgin oviparae of the potato aphid Macrosiphum euphorbiae (Thomas) (Homoptera: Aphididae) was studied at three different constant temperatures under laboratory conditions. The mean age of calling for the first time decreased with a decrease in temperature from 2.9 days at 20 °C to 2.1 days at 10 °C. At all temperature regimes, the mean onset time of calling advanced from about 5 to 3 h after the onset of the photophase, and the mean time spent calling increased by > 4 h over the 8 days.
2. Cohorts of oviparae were also observed at two different periods in late summer–early autumn in the field, to examine the effects of fluctuating abiotic conditions (temperatures, wind velocity, rain) and age on calling behaviour. As under constant laboratory conditions, the mean age of calling for the first time declined with declining temperature, from 3.7 days in early September to 1.6 days at the end of September. Age-related changes in the mean onset time of calling and the mean time spent calling were much less evident under field conditions, due to the inhibitory effects of low temperatures, high winds, and rain on female calling activity.
3. The results are discussed within the context of reproductive success and address a previously proposed hypothesis suggesting that species-specific calling windows may serve as a reproductive isolating mechanism for sympatric aphid species.     

Temperature and the tropical tortoise Kinixys spekii: constraints on activity level and body temperature

Movements of five Kinixys spekii were measured continuously during six weeks of their activity season, by thread-trailing. The mean daily movement distance was negatively correlated with maximum shade air temperature, but not significantly related to minimum temperature, rainfall, or humidity. There was a midday period of inactivity of increasing length as maximum air temperature exceeded 29° C. Temperatures of models suggest that lower activity on hot days was due to the risk of overheating in this small (mean mass 617 g) tortoise. Kinixys spekii had a mean field body temperature (T^b) of 27° C, which is low compared to other tortoises (including sympatric Geochelone pardulis, mean T^b= 32.5° C), but salivated at a similar T^b (38.4° C). This pattern also occurs in other small species; mean and maximum field T^bs of tortoises are positively correlated with body mass, but salivation and critical maximum T_bs do not vary with body mass. Low field T_b provides a wide safety margin before evaporation of water becomes necessary. Kinixys sprkii had a short annual activity period, with about 95% of sightings in four months (December to March). Monthly sightings of K. spekii were correlated with rainfall, but not significantly related to temperature or humidity. Seasonal activity is therefore related to rainfall, but within the rainy season the level and pattern of daily activity is related to temperature.