Diurnal Hours Research Articles

SPATIAL ECOLOGY OF SWIFT FOX SOCIAL GROUPS: FROM GROUP FORMATION TO MATE LOSS

We examined social group formation, movements and denning relative to other group members, home-range use, and the response to social group disruption among 188 radiocollared swift foxes (Vulpes velox) in Colorado. We found that during the initial stages of pair formation mated foxes shared dens more frequently than during the remainder of their pair-bond. The average distance between mated pairs was influenced by season and time of day, with the greatest proximity in the breeding season (727.2 m ± 42.3 SE), and during diurnal hours (463.7 ± 34.7 m). Female foxes spent more time in the core area of the group home range (60.71% of locations versus 54.66% for males) and males spent more time on the range boundary (19.34% of locations versus 15.61% for females). Home-range use was influenced by season, with females spending more time in the core area in the breeding and pup-rearing seasons than in the dispersal season. Males also spent the highest proportion of their time in the core area during the breeding season, but used the boundary area more frequently than the core area in the pup-rearing season. A sex difference also was found in the response of a swift fox to the death or disappearance of its mate. All females maintained their territory in the event of mate death or disappearance; however, 50% of males emigrated from their range when the female mate died or disappeared. These differences in space use between social group members provide important insights into the territorial behavior and mating system of the swift fox and indicate that the 2 sexes likely play different roles in care of young and home-range defense.

Sleep disorders in advanced cancer patients: prevalence and factors associated.

Sleep disorders have been invariably reported in cancer population. However, the prevalence of this problem in advanced cancer patients has never been assessed. The aim of this study was to evaluate the frequency of sleep disturbances in terms of quantity and quality, and possible associated factors. A consecutive sample of patients admitted to a pain relief and palliative care unit were surveyed. Patients with severe cognitive problems or who were too ill were excluded. Epidemiological and clinical data, including the performance status, habits, relevant symptoms, and drug use were recorded. Patients were asked to answer a small questionnaire regarding their sleep, and duration and characteristics (nocturnal and diurnal hours slept, falling asleep, awaking, getting back to sleep, early awaking, restoring sleep, nightmares, feeling depressed or anxious). The level of information about the illness was also assessed. Among the causes of admission, pain control was the main indication (about 58%). Of 123 patients surveyed, 30% slept less than 5 h. Women significantly slept more hours than men (p=0.042). Anxiety (p=0.045), falling asleep (p=0.003), awaking (p=0.035), early awaking (p=0.001), getting beck to sleep (p=0.021), and nightmares (p=0.034), were significantly associated with less hours slept. This relationship was highly significant for less restoring sleep, fatigue, and drowsiness ( p<0.0005). No differences were found for age (p=0.294), primary tumor (p=0.225), level of information ( p=0.529), Karnofsky status (p=0.539), depression (p= 0.095), confusion (p=0.074), possible causes of awaking (p= 0.881), use of opioids (p= 0.798), use of hypnotics (p= 0.197), other morbidities ( p=0.460), or use of alcohol or coffee (p= 0.141). Patients admitted for pain control and/or those receiving opioids more frequently had drowsiness (p=0.01) Patients with lower Karnofsky scores had more drowsiness and diurnal hours slept (p=0.01). Anxiety created more difficulties in falling asleep, produced a less restoring sleep, and nightmares. Depression was associated with early awaking, nonrestorative sleep, fatigue, and nightmares. Confusion was associated with fatigue and nightmares. Sleep problems appear to be a significant issue for advanced cancer patients. Attention to sleep disturbance needs to be incorporated into the routine practice in palliative care evaluation.

Den Site Activity Patterns of Adult Male and Female Swift Foxes, &lt;em&gt;Vulpes velox&lt;/em&gt;, in Northwestern Texas

Activity of Swift Foxes (Vulpes velox) at den sites was studied in northwestern Texas during pup rearing seasons in 2000 and 2001 to determine role of males in parental care. Twenty-four percent of radio-collared females with a potential to breed successfully raised pups to eight weeks of age. We intensively monitored presence and absence of male and female Swift Foxes at two den sites each year. Females were present &gt;2.6 times more at den sites than males during the pup rearing season. Female and male Swift Foxes largely stayed at dens during diurnal hours and were active away from dens during nocturnal and crepuscular hours. Females and males spent 12.4% and 3.0% more time at dens before pups emerged, than after pups emerged, respectively. Following depredation of one male parent, the female spent 29% less time at the den site. Decrease in time spent at the den by the female following loss of her mate suggested that loss of one parent might severely impact recruitment of Swift Foxes. Our observations indicated that intense Coyote (Canis latrans) depredation may severely impact pup-rearing success as well as the parental care within Swift Fox family groups.

Habitat Use by Cottontail Rabbits across Multiple Spatial Scales in Mississippi

Relative importance of different land-cover types is often inferred from studies of habitat selection in the context of availability. From 1 February 1997 to 31 January 1999, we examined seasonal (breeding and nonbreeding) habitat selection of cottontail rabbits (Sylvilagus floridanus) in an agricultural landscape in east-central Mississippi at multiple spatial scales (second-, third-, and fourth-order habitat selection; Johnson 1980). We characterized available land-cover types as woody, rowcrop, or grass. The composition of seasonal rabbit home ranges (95% Adaptive Kernel [HR]) and core areas (50% Adaptive Kernel [CA]; second-order selection) exhibited selection for grass patches, followed by woody and rowcrop patches. However, genders differed across diel periods for the composition of HR. Males selected woody patches during diurnal hours, and females selected grassy patches, whereas they both selected grassy patches during the nocturnal hours. Within HR, allocation of time among habitats (third-order selection) differed between seasons and genders. Males selected grass patches followed by woody and rowcrop during the breeding season, and females used them in proportion to availability, whereas they both used them in proportion during the nonbreeding season. Genders used HR land-cover types in proportion to availability for both diel periods. Two predictive models of fourth-order selection poorly discriminated (56.9% and 60.7%) between used and random locations. Cottontails exhibited habitat selection at the HR (second-order) and males at the patch scale (third-order); however, cottontails randomly used within a patch (fourth-order). Our results support the characterization of cottontails as vegetative community generalists at the patch scale (fourth-order); however, cottontails select among land-cover types at larger spatial scales (second- and third-order).

Evening mist‐net closure: Implications for data collection and bird welfare

Wild birds captured with mist‐nets for study purposes should be released and returned to the wild as soon as possible to reduce the stress of being handled. Studies of migratory birds involving mist‐netting for 24h/day may result in diurnal birds being caught late in the day and kept overnight. This may be particularly detrimental to migrants stressed by migratory flight and to sedentary birds during reproduction. The closure of mist‐nets in the evening may avoid these problems, but is believed to severely reduce the amount of data collected. In this study we show that the evening closure of mist‐nets does not translate into a significant reduction in captures of migrants because the number of migrants captured in the evening is low, and the reopening of mist‐nests before sunrise does not reduce the captures in the following diurnal hours. The evening closure of mist‐nets reduced disturbance because it avoided keeping both, nocturnal migrants (including those which were about to leave the study area) and sedentary birds overnight. Therefore, mist‐nets may be closed in the evening without jeopardising the success of a study. The loss of data caused by the evening closure of mist‐nets may however be significant for the few species with partially or completely crepuscular activity such as the Nightingale, Luscinia megarynchos.

Twenty-four hour activity budgets and patterns of behavior in captive ocelots ( Leopardus pardalis)

Activity budgets of captive ocelots ( Leopardus pardalis) were assessed from over 547 h of observational data obtained from six ocelots; two females at the Dallas Zoo (Dallas, TX), two females at the Caldwell Zoo (Tyler, TX) and a male and female at the Fossil Rim Wildlife Center (Glen Rose, TX). Data were examined for the percentage of active behaviors exhibited during the day and nighttime hours; temporal patterns of active, pace, exploratory and marking behavior, and for significance in pacing behavior between pre- and post-feeding times. The captive cats had a bimodal pattern of active behavior similar to field studies of wild ocelots, except that the timing of the active peaks were closer to the diurnal hours for the captive cats. The captive ocelots were less active than wild ocelots, and more diurnal. Also, the captive cats exhibited stereotypic pacing. When the percentage of time of active behavior was assessed for each cat, a strong variation between individuals and institution was not seen. Pacing behavior was highest prior to the feeding times for the cats. In assessing patterns of behavior, peaks in marking and exploratory behavior in the cats did not occur at the same time as the peaks in active behavior. However, we did see institutional differences in the pattern of exploratory and marking behavior, which may have been influenced by differing management practices.

Resource partitioning between coyotes and swift foxes: space, time, and diet

In its current distribution and abundance, the swift fox (Vulpes velox) has been significantly reduced from its historic range. A possible cause is competition with, and predation by, coyotes (Canis latrans). We investigated the level of spatial, temporal, and dietary resource use overlap between swift foxes and coyotes at the Pinon Canyon Maneuver Site in southeastern Colorado. We captured and radio-tracked 73 foxes and 24 coyotes from April 1997 to August 1998. We collected 10 832 and 5350 locations of foxes and coyotes, respectively. Overall, home-range sizes of foxes and coyotes were 7.6 ± 0.5 (mean ± SE) and 19.8 ± 1.9 km2, respectively. A high degree of interspecies spatial overlap was apparent, with fox home ranges being overlapped by coyote home ranges by as much as 100% and coyote sign (tracks and scats) being evident in all swift fox home ranges. There was no evidence of temporal avoidance of coyotes in fox movement patterns. Coyotes traveled significantly farther than foxes during diurnal hours; foxes spent the majority of diurnal hours in or on top of dens. Coyotes and foxes showed a high index of overlap for dietary resources, although some dietary partitioning was apparent. Swift foxes specialized in small prey, such as insects and rodents, while coyotes used greater proportions of large prey, such as lagomorphs and ungulates. Interference competition was evident, with 48% (12/25) of fox mortalities identified as confirmed or probable coyote-caused deaths. In each case, death occurred outside either the fox's home range or the 85% isopleth of that range, indicating that coyotes are more likely to attack a fox successfully when it is a substantial distance from a den. We propose that swift foxes are able to coexist with coyotes, owing to year-round den use and a degree of dietary partitioning.

Activity Patterns of Nesting Mexican Spotted Owls

We collected 2,665 hr of behavioral information using video surveillance on 19 Mexican Spotted Owl (Strix occidentalis lucida) pairs between 25 April and 26 July 1996. Prey deliveries per day increased as the nesting season progressed, with an average of 2.68 prey deliveries during incubation, 4.10 items during brooding, and 4.51 items during the nestling phase. The highest delivery rates were concentrated between 1-3 hours before sunrise (02:00-05:00) and 1-3 hours after sunset (18:00-21:00). Trip duration during diurnal hours increased 14 fold from incubation through the nestling phase, compared with a 7.2 fold increase during nocturnal hours. Nest bout duration decreased during both diurnal (36%) and nocturnal hours (76%) across the nesting season. Nest attentiveness decreased as the nesting season progressed, from 97% during the incubation phase to 47% during the nestling phase. Owls attended nests at higher rates during diurnal hours than nocturnal hours across all nesting phases. Activity patterns of Mexican Spotted Owls showed marked cyclical changes in response to ecological factors. Fluctuations in nesting behavior were related to changes in nesting phase and time of day.

Some theoretical of ionospheric storms at middle latitudes

Neutral wind effects in the F2-region during geomagnetic storms are theoretically studied solving the continuity equation (with production and loss of electrons) by means of a numerical method. This study was made for storms with sudden commencement at different times of day and at different latitudes. The results show that the equatorward movements of neutral air produce either enhanced or depressed maximum electron density values which depend on the velocity of these winds when the perturbation occurs at diurnal hours. If the geomagnetic storm is present during the night, only enhanced values are observed.

Noise pollution in an intensive care unit for nephrology and dialysis.

By means of high sensitivity phonometers, noise levels in different sites of an intensive care unit (ICU) for nephrology and dialysis were evaluated before and after acoustical renovation of the rooms. The noise levels registered in the diurnal hours of the working day were always higher than those recommended for sites devoted to patient care. The authors analysed the negative effects of noise pollution on nephrology patients and the medical personnel of the unit.

Continuous heart rate variability monitoring through complex demodulation implemented with the fast Fourier transform and its inverse.

A new method for the analysis of 24-hour heart rate variability (HRV) using complex demodulation (CDM) implemented with the fast Fourier transform (FFT) and its inverse is described. In a control group with palpitations and dizzy spells (n = 30, 47.2 +/- 16.7 years) the relationship between HRV parameters and subject age was investigated. CDM was used to obtain the amplitude and frequency of the low frequency (LF) and high frequency (HF) oscillations for 8 diurnal hours and 4 nocturnal hours. Differences between the two periods were seen in the LF/HF ratio (2.2 +/- 0.6 vs 1.5 +/- 0.6; P < 0.0001), HF amplitudes (12 +/- 6 vs 17 +/- 7 normalized units, P < 0.05), and in the mean frequency of the LF oscillations (0.078 +/- 0.008 vs 0.073 +/- 0.007 Hz, P < 0.01). During the daytime, age was inversely correlated to HF amplitude (r = -0.60), directly correlated to HF mean central frequency (r = 0.40), inversely correlated to LF amplitude (r = -0.55), and likewise inversely correlated to LF mean central frequency (r = -0.74, P < 0.001). At night, age was only inversely correlated to HF amplitude and to LF mean central frequency. Continuous HRV monitoring through CDM implemented with the FFT and its inverse differentiates the periods of diurnal activity and nocturnal rest as an expression of two different activity states of the autonomic nervous system. It allows nonstationary analysis, and separately provides mean and instantaneous oscillation amplitude and frequency. Subject age is not equally related to mean amplitude and frequency of a given oscillation.

4 GONADOTROPIN SECRETION IN CONGENITAL ADRENAL HYPERPLASIA (CAH)

Menstrual disorders are frequent in women with CAH. With the purpose to analyze the effect of the hyperandrogenism on gonadotropin secretion, we have studied 12 women with 21 hidroxilase defiency, X age 19. 3years;six had amenorrhea, 4 oligomenorrhea and 2 were eumenorrheic. One of them had never received treatment, 2 stopped treatment 2-3 years before and 9 were on corticoid replacement. Serum E2, 17OH progesterone (17 OHP), urinary 17-Ketosteroids (17-KS)and pregnanotriol (triol), and spontaneous LH and FSH levels every 20 minutes during 12 nocturnal hours (5 studies) or 4-6 diurnal hours (8 studies), were measured. Results: Three patterns of gonadotropin secretion were detected: 1)Apulsatile, n=7: X LH 1.2±0.3 IU/L; 2)Low pulsatility n=4: X LH 2.7±1.1 IU/L, X pulse amplitude (P.A.) 3.2±1.6, X pulse frecuency (P.F.) 0.23±0.08 p/hour;3) Normal pulsatility n=2 X LH 7.6 IU/L, P.A. × 4.9 IU/L, P.F. × 0.43 p/hour. No correlation was observed between gonadotropin levels and 17OHP, 17-KS or triol at the moment of study; a weak(ns)correlation was found with those values1-2 years before the study. Two patients with optimal corticoid replacement since birth, and two untreated patients presented an apulsatile gonadotropin secretion pattern. Conclusion: CAH due to 21 hydroxylase deficiency is associated with variable degrees of impaired gonadotropin secretion, even in patients with adequate corticoid treatment, suggesting an hypothalamic alteration as a consecuence of the prenatal exposure to high androgen levels.

Diurnal versus 24-Hour Sampling of Habitat Use

Habitat use estimates may be biased if the sampling design does not consider differences in a species' habitat use throughout a 24-hour period. We reviewed studies to examine the suitability of sampling designs in determining habitat use relative to a species daily activity pattern. Of 56 studies we reviewed, 22 presented data only from daylight sampling and 12 did not describe their methods with enough detail to determine when sampling occurred. Elk (Cervus elaphus) habitat use throughout the entire 24-hour period was different (P < 0.001) from that during diurnal hours. Managers should be cautious when implementing management strategies developed only from diurnal datasets

Nocturnal Activity of Female Desert Mule Deer

Most studies of deer activity occur during diurnal hours; nocturnal activity is rarely addressed. For desert mule deer (Odocoileus hemionus crooki), diurnal studies alone may not represent normal activity rhythms resulting from heat stress at certain times of the year. To understand diel activity patterns, nocturnal activity should be examined to see if and how diurnal and nocturnal activities differ. Thus, we quantified nocturnal activity of 5 radio-collared female desert mule deer in the Belmont and Big Horn mountains, Arizona in 1990. We determined their movements and estimated activity with observations and a digital processor. We compared areas used by deer at night with areas used during the day

Daily variations in concentration of vasoactive intestinal peptide immunoreactivity in hypothalamic nuclei of rats rendered diurnal by restricted-schedule feeding

We previously described that in the suprachiasmatic (SCN), peri-(PeVN) and paraventricular (PaVN) nuclei of normal rats, vasoactive intestinal peptide (VIP)-like immunoreactivity (VIP-LI) accumulates during the night period and decreases during the day. In order to determine whether these variations are linked to the light-dark cycle or are a consequence of sleep-wake rhythm expression, we dissociated these two parameters by restricting feeding to diurnal hours. In these conditions which inverse the paradoxical sleep rhythm, the VIP-LI pattern is perturbed and its minimum advanced by 4 h in the SCN. In the PeVN, the daily pattern is maintained but the minimum is also advanced by 4 h. Finally, the rhythm is abolished in the PaVN. These circadian fluctuations indicate that the hypothalamic VIP-LI rhythm is not linked to the paradoxical sleep rhythm but could be sensitive to photic and non-photic Zeitgeber.

Bark temperature patterns in mountain pine beetle susceptible stands of lodgepole pine in the central Rockies

Bark temperatures were recorded on five lodgepole pine (Pinuscontorta Dougl. ex Loud.) in stands of different growing stock levels in Colorado and Wyoming. Mean bark temperatures were significantly different among growing stock levels. Temperatures in the partially cut growing stock levels were significantly warmer than in uncut controls during diurnal hours, but temperatures were cooler during nocturnal hours. Bark temperatures correlated with ambient air temperature. Equations were developed for predicting north- and south-side bark temperatures for partially cut stands of three growing stock levels and an uncut control from air temperatures. Bark temperature patterns in lodgepole and ponderosa pine (Pinusponderosa Laws.) stands are compared. The relationship between growing stock level and mountain pine beetle (Dendroctonusponderosae Hopk.) infestation is discussed from the standpoint of bark temperatures.

Diel Activity of Female Desert Bighorn Sheep in Western Arizona

We studied diel activity of female desert bighorn sheep (Ovis canadensis mexicana) in the Little Harquahala Mountains, Arizona, from 1 July 1985 through 30 June 1986. The Little Harquahala Mountains did not contain free-standing water so we measured diel moisture content of key forage species each season to determine if bighorn sheep activity was related to plant moisture. Activity of bighorn sheep was divided into 4 behavior classes (bedding, standing, moving, and foraging) for diurnal hours, and 2 classes (active and nonactive) for nocturnal hours. Diurnal activity patterns were similar throughout the year. Nocturnal activity patterns were similar for all seasons except spring, when activity decreased (P = 0.003). Bighorn sheep were active a mean of 39 and 33% of any given hour during the day and night, respectively. Diurnal ambient temperatures and relative humidity were correlated (P 32% for each hour of the day for each season; we did not detect relationships between activity patterns of desert bighorn sheep and moisture content of plants. J. WILDL. MANAGE. 53(1):264-271 Animals in deserts are exposed to at least 2 major interrelated physiological problems: maintenance of an adequate water balance and suitable body temperature (Bradley 1963). Water is available to animals from metabolic water formed during oxidative metabolism, preformed water in food, and surface water (Turner and Weaver 1980). Turner (1973) stated that water requirements for bighorn sheep were equivalent to 4% of their body weight/day and this amount could not be obtained solely from forage during hot, dry periods. However, 15-20 bighorn sheep inhabit the Little Harquahala Mountains, where permanent free-standing water is not available during the summer dry season (Krausman et al. 1985). Neither of 2 female bighorn sheep observed by Krausman et al. (1985) drank water during 10 days of observation even though they were active 21% of nocturnal hours. Therefore, it appears that during long periods with little or no rainfall some bighorn sheep can survive on preformed or metabolic sources of water, or possibly by foraging at night when temperatures are cooler and forage moisture may be higher. We were interested in determining the relation hip between daily activity patterns of bighorn sheep and patterns of moisture in plants sheep consume. Our objectives were to monitor diel activity of female desert bighorn sheep and describe the effect of time of day, season, group size, temperature, and relative humidity on acivi y; determine if there are seasonal patterns in the moisture content of key forage species used by bighorn sheep; and describe any relati nships that exist between forage moisture and bighorn sheep activity. We thank M. T. Brown, T. Kerpez, T. L. Steel, and G. D. Warrick for their field assistance. D. M. Leslie, Jr., R. W. Mannan, W. J. Matter, T. R. McCabe, and K. R. Rautenstrauch critically reviewed the manuscript. Funding for this project was provided by the U.S. Bureau of Reclamation and the U.S. Fish and Wildlife Service.

Aggregation in snails, Achatina fulica

The spatial distribution of juvenile terrestrial snails was studied in clean, symmetrical plastic boxes. Environmental stimuli capable of biasing particular locations in the boxes were reduced to a minimum. Under these conditions, it was found that snails cluster significantly above chance levels. The degree of aggregation is related to the age of the animals, their genetic relationship, and the time of day. Recently hatched snails aggregate less than older animals. Aggregation is greater when the sample population consists of snails hatched from a single clutch of eggs than when it is derived from two different clutches. Aggregation is greater at night than during the diurnal hours. The sensory basis of the phenomenon is considered to be olfactory.

Bionomics of Psorophora Ferox (Diptera: Culicidae): Seasonal Occurrence and Acquisition of Sugars

Despite erratic annual and seasonal distributions of Psorophora ferox in a woodland habitat, males and females consistently contained fructose or sucrose throughout diurnal hours. Anthrone tests detected nectar sugars in 38% of 1000 females and 48% of 497 males captured between 0900 and 2100 h in August 1976. Percentages of nectar-positive resting (82%) and blood-seeking females (71%) were greatest during 1701–1900 h. Nectar-positivity for males generally exceeded that of females throughout the day. Although Aster divaricatus (white wood aster) and Aster lowrieanus (Lowrie's aster) served as nectar sources during evening crepuscular periods (1901–2100 h), only 66 females and 58 males were observed on blossoms. Chemical test results suggest a much higher frequency of feedings on sugars than is indicated by visual sightings on flowers.

Diurnal Nectar-Feeding of Aedes cantator and A. sollicitans (Diptera: Culicidae) 1

A 50-m2 salt marsh study plot was used from 0800 to 2000 h to observe diurnal associations of Aedes cantator (Coquillett) and Aedes sollicitans (Walker) with Chrysanthemum leucanthemum L. (ox-eye daisy), Achillea millefolium L. (yarrow), and Hieracium pratense Tausch (king-devil hawkweed) and to determine periods of most active biting intensity on humans. Both sexes of each species were more frequently collected from flowers of plants in peak bloom and at high relative densities. Diurnal shifts in the selection of host plants were not apparent. Of the total 1711 mosquitoes captured from blooming plants, significantly more individuals (66%) were observed probing floral and non-floral structures between 1600 and 2000 h. Periods of peak association with nectar sources and times of maximum blood-seeking activity were synchronous for each species. Anthrone tests detected fructose and sucrose in resting and blood-seeking mosquitoes throughout diurnal hours, but in each behavioral group, significantly more A. cantator and A. sollicitans females (65–89%) contained these sugars at 2000–2100 h. Percentages of nectar-positive males (≥55%)consistently exceeded those of females for both species between 0800 and 1700 h; no differences could be found between sexes during 1700–2100 h. Relatively high frequencies of nectar-positive males and females suggest repeated daily associations of these salt marsh mosquitoes with sugar sources.