The locomotory activity patterns of a functionally complete colony of Cryptomys hottentotus hottentotus (Rodentia: Bathyergidae)

The locomotory activity patterns of a colony of eight field-captured mole-rats housed in a transparent burrow system were monitored for a total of 240 hours. Movement along the burrow system was recorded for all hours of the 24-hour chronological day for 10 days. Intermittent periods of activity were characteristic for all the mole-rats in the colony. The lack of a distinct sleeping period reflects the asynchrony of each mole-rat's activity cycle with that of other colony members. There are four major peaks of activity during the 24-hour cycle and an absence of a well-defined diurnal or nocturnal phase to the activity cycle.
The nest area is a focal point in the burrow system with individuals spending between 36 and 81% of the day there. There is a positive correlation between the size of a group of sleeping mole-rats in the nest and the frequency of occurrence.     

Burrow ventilation and associated porewater irrigation by the polychaete Marenzelleria viridis

Burrow ventilation of benthic infauna generates water currents that irrigate the interstices of the sediments surrounding the burrow walls. Such activities have associated effects on biogeochemical processes affecting ultimately important ecosystem processes. In this study, the ventilation and irrigation behavior of Marenzelleria viridis, an invasive polychaete species in Europe, was analyzed using different approaches. M. viridis showed to perform two types of ventilation: (1) muscular pumping of water out of the burrow and (2) cilia pumping of water into the burrow. Flowmeter measurements presented muscular pumping in time averaged rates of 0.15 ml min⁻¹. Oxygen needle electrodes positioned above the burrow openings revealed that muscular undulation of the worm body pumps anoxic water out of the burrow. On the other hand, microscope observations of the animal showed that ventilation of oxygen-rich water in the burrow occurs by ciliary action. The volume of water irrigated by M. viridis appears to vary linearly within the first 24 h incubation, with rates ranging from 0.003 to 0.01 ml min⁻¹. From those rates we could estimate that the time averaged rate of cilia ventilation should be about 0.16 ml min⁻¹. Since the cilia pumping into the burrow occurs in periods of 24 ± 12 min and at 50-70% of the measured time, considerable amounts of water from deeper sediments may percolate upwards to the sediment surface. This water is rich in reduced compounds and nutrients and may have important associated ecological implications in the ecosystem (e.g. affecting redox conditions, organic matter degradation, benthic recruitment and primary production).     

Development of survival skills in captive-raised Siberian polecats (Mustela eversmanni) I: Locating prey

Captive-raised mustelids appear to have a rudimentary capacity to kill prey, but the skills necessary for locating prey may be eroded during captivity. We tested the maturational component of prey-searching behavior with captive-raised Siberian polecats (Mustela eversmanni) by subjecting polecats to a simulated prairie dog colony of 6 burrows within a 200 m² arena. Ten naive Siberian polecats at ages 2.5, 3.5, and 4.5 months (30 total) were deprived of food for 12 hours. A dead prairie dog was placed in 1 prairie dog burrow and the other 5 were empty. A single Siberian polecat was released onto the colony shortly before sunset and its movements monitored from an observation tower. Older Siberian polecats located prey significantly quicker than younger polecats, but all age groups spent a great deal of time in surface activity not directed toward a burrow. When Siberian polecats were about 10 months old, all burrows in the arena were plugged with dirt including the burrow with the prairie dog. In this winter test, Siberian polecats located the prey but still spent a great deal of time in non-burrow directed surface activity. Economical use of surface time, with a low amount of non-burrow directed behavior, would presumably reduce the risk of predation for hunting polecats.     

The daily activity of the elephant in the Rwenzori National Park, Uganda

Eighteen elephants were followed individually in the Rwenzori National Park, Uganda for varying periods and their activity noted at 4-min intervals. Continuous data extending over 24 h or more were collected from seven of these elephants. About 75% of the total time was spent in feeding and about 75% of the feeding activity consisted of grazing or feeding at ground level. There were three feeding peaks, one in the morning, another in the afternoon and the third around midnight. The feeding rate tended to increase during the day. The proportion of the total feeding time spent in browsing increased in the dry season. Walking took place mainly at dusk. The principal sleeping period occurred during the small hours of the morning with a shorter rest period in the early afternoon. The elephants defaecated about eleven times in the 24 h and drank an average of 1–3 times. The rate of progress through the bush averaged 0–5 km/h. Comparisons are made with published data concerning the activity patterns of waterbuck and warthog in the Rwenzori Park and of elephants in the Tsavo National Park, Kenya.     

大沙鼠洞道利用机制及地面行为时间分配特征

2010年5—11月,在古尔班通古特沙漠南部采用焦点动物取样法研究了大沙鼠(Rhombomys opimus)的昼间洞道利用机制(地面活动强度、进洞频率)以及地面行为时间分配。结果表明:大沙鼠在春夏秋三季地面活动时间占总观察时间的77.62%、66.13%和80.93%,进洞频率分别为0.50、0.31和0.19次.min-1,地面活动强度和进洞频率均具有明显的季节性变化;在其地面行为中,摄食是大沙鼠任一季节最主要的行为,不同季节摄食比例均超过50%;储食是大沙鼠春季两秋两季次重要的行为,其时间比例分别达到了17.19%和25.46%;夏季大沙鼠修饰行为比例明显升高(27.78%),而储食行为比例明显下降(7.1%)。本研究结果说明,食物因子是促使大沙鼠进行地面活动的重要因素之一;另外,温度、生理周期、捕食风险可影响大沙鼠地面活动强度、进洞频率以及地面行为时间分配。     

The impact of polychaete (Nereis virens Sars) burrows on nitrification and nitrate reduction in estuarine sediments

The influence of Nereis virens Sars burrows on nitrification, denitrification and total nitrate reduction was assessed in poor (0.7% organic matter) and rich (2.0% organic matter) sediment from the estuary, Norsminde Fjord. The experiments were performed as assays of potential activity, since natural conditions proved impossible to simulate in the unpredictable burrow environment. The measurements were made in two microprofiles, extending 15 mm into the sediment from the surface and from the burrow wall lining. Both sediment types showed higher potential nitrification in the wall linings than in the surface sediment. This was positively correlated with the content of silt + clay particles and organic matter (i.e. the mucous lining of burrow walls). An elevated nitrate reduction activity was evident in the oxic layer of surface sediment. No such activity pattern was observed in the burrow walls. Denitrification accounted for 27–53 % of the total nitrate reduction. An empirical relationship between the ratio of predicted oxygen penetration into surface and wall sediment and the contribution of nereid burrows to bulk actual nitrification and nitrate reduction is presented. The burrow contribution to bulk nitrification was, in contrast to bulk nitrate reduction, very sensitive to variable oxygen penetrations. Thus, possible short-time changes in nitrate exchange across the wall lining will apparently be regulated by changes in nitrification activity rather than nitrate reduction activity.     

Stereotypies resulting from a deviation in the ontogenetic development of gerbils

As a reaction to intensive housing conditions, Mongolian gerbils (Meriones unguiculatus) regularly develop stereotypic digging in early ontogeny. To determine how the development of stereotypic digging deviates from the development of digging in a natural setting, the development of digging in laboratory cages and an artifical burrow were compared. In the burrow treatment, young gerbils were raised inside the burrow and left it for the first time at a mean age of 21 days. They showed a strong tendency to retreat into the burrow and spent 91.6% of the time in it. Their digging consisted of short, non-stereotypic digging bouts. In contrast, digging of the young gerbils in the laboratory cages became increasingly longer and consisted of long-lasting, stereotypic digging bouts along with short, non-stereotypic bouts. This development deviated from the development in the burrow significantly from day 24. Stereotypic digging was interpreted as an intensification of digging due to a lack of retreating structures in the laboratory cages. Stereotypic digging was considered as an abnormal behavior because it failed to regulate retreating behavior.     

Breeding biology and conservation of the Black-vented Shearwater Puffinus opisthomelas

The Black-vented Shearwater Puffinus opisthomelas is endemic to the Pacific coast of Baja California, Mexico. We studied the breeding biology of this species at Natividad Island in 1997 and 1998. The colony at Natividad Island covers approximately 2.5 km² and we estimated there to be 114 455 (± 27 520 95% CI) burrows in the colony. In 1997 burrow occupancy was 66.9%, providing a population estimate of 76 570 (± 18 411 95% CI) breeding pairs, representing about 95% of the world's population of this species. In 1997 the peak in egg laying occurred in early March and hatching began on 7 May. The incubation period averaged 51 days (± 6 sd) and chick rearing averaged 69 days (± 3 sd). In 1998 burrow occupancy was lower (19.6%) and nest initiation was later (peak egg laying in mid-April), perhaps a result of El Niño conditions that prevailed in the Eastern Pacific at that time. We calculated that the development of the town and roads on Natividad Island have destroyed over 15% (26 532 burrows) of the breeding habitat on the island.     

Cost-effectiveness of five burrow fumigants for managing black-tailed prairie dogs

We evaluated the cost-effectiveness of two solid form burrow fumigants (aluminum phosphide and gas cartridges) and three pressurized gas–liquid burrow fumigants (methyl bromide, chloropicrin, and a methyl bromide–chloropicrin mixture) for managing black-tailed prairie dogs (Cynomys ludovicianus). Fifty-two variable-sized plots, including 25 treatment and 25 control burrows, were established within 13 prairie dog colonies in central Nebraska during spring 1989. Each group of 25 treatment burrows was fumigated with one of the five fumigants according to label directions or manufacturer recommendations. All five fumigants reduced burrow activity 95–98%, as measured by a plugged burrow technique. No significant differences in efficacy (P=0.453) were detected among the five treatments. Total costs for materials and labor for the aluminum phosphide and gas cartridges, excluding application equipment, were twice ($75.00 to $96.88 ha⁻¹) the cost of the pressurized gas–liquid fumigants ($37.67 to $41.76 ha⁻¹). Costs for the application equipment were considerably higher for the pressurized materials. Each treatment required labor for burrow plugging, which accounted for 50–75% of the total cost. None of the products tested met all requirements of a proposed selection criteria for fumigants.     

The microenvironment of house mice on Marion Island (sub-Antarctic)

On Marion Island, house mice ( Mus musculus) establish burrow systems that range from unbranched corridors 0.5 m long with a single chamber (in some instances without a chamber) to complexly branched systems extending over an area of up to 4 m² and containing up to four chambers. Total underground area occupied by burrow systems (chambers plus corridors) was from 5 to 23 m² ha^-1, corresponding to burrow-system volumes of 250-1,300 dm³ ha^-1. In autumn, about three-quarters of chambers contained small food caches. Most (87%) entrances to burrow systems faced away from prevailing winds, especially winds that bring snow, hail or rain. Seasonal and diurnal temperature variations in burrows are considerably dampened (daily minimum in burrows seldom drops below 2°C), compared with the air just above the vegetation canopy. Over the whole year, total night-time warmth in a burrow (heat sum, 24,883 degree hours) was 53% greater than at the top of the canopy (16,317 degree hours). Burrows' entrances are generally connected above ground by runways (paths and tunnels through the vegetation). Runways also represent a warmer environment than the air above the canopy during the breeding season at night (13,466 degree hours at the runway surface compared with 11,900 degree hours at the top of the canopy). House mice, which are living close to their physiological limits, temperature-wise, on Marion Island thus evade the worst extremes of the island's climate by constructing burrows and above-ground runways and this is an important factor in their survival.     

高原鼠兔领域行为时间分配格局及其对风险环境适应的探讨

采用直接观察法测定了高原鼠兔地面、洞道活动时间及进、出洞频率。结果表明,在07：00-18：00,雄性和雌性高原鼠兔平均地面活动时间分别占总活动时间比例的87．09％和85．22％。地面活动时间具有明显的季节性,但两性个体间无显著的差异。繁殖早期,成年雌体地面活动时问显著高于繁殖后期,第2胎幼体地面活动时间显著低于第1胎幼体。不同年龄和性别的高原鼠兔进洞频率存在极显著差异,5月成年雌体进洞频率最高,而成年雄体在4月进洞频率最低。研究结果验证了捕食风险可制约鼠兔属动物领域活动时间分配,高风险环境能增加其利用洞道的时间及频率的特定假设。     

Depth of artificial Burrowing Owl burrows affects thermal suitability and occupancy

Many organizations have installed artificial burrows to help bolster local Burrowing Owl (Athene cunicularia) populations. However, occupancy probability and reproductive success in artificial burrows varies within and among burrow installations. We evaluated the possibility that depth below ground might explain differences in occupancy probability and reproductive success by affecting the temperature of artificial burrows. We measured burrow temperatures from March to July 2010 in 27 artificial burrows in southern California that were buried 15–76 cm below the surface (measured between the surface and the top of the burrow chamber). Burrow depth was one of several characteristics that affected burrow temperature. Burrow temperature decreased by 0.03°C per cm of soil on top of the burrow. The percentage of time that artificial burrows provided a thermal refuge from above‐ground temperature decreased with burrow depth and ranged between 50% and 58% among burrows. The percentage of time that burrow temperature was optimal for incubating females also decreased with burrow depth and ranged between 27% and 100% among burrows. However, the percentage of time that burrow temperature was optimal for unattended eggs increased with burrow depth and ranged between 11% and 95% among burrows. We found no effect of burrow depth on reproductive success across 21 nesting attempts. However, occupancy probability had a non‐linear relationship with burrow depth. The shallowest burrows (15 cm) had a moderate probability of being occupied (0.46), burrows between 28 and 40 cm had the highest probability of being occupied (>0.80), and burrows >53 cm had the lowest probability of being occupied (<0.43). Burrowing Owls may prefer burrows at moderate depths because these burrows provide a thermal refuge from above‐ground temperatures, and are often cool enough to allow females to leave eggs unattended before the onset of full‐time incubation, but not too cool for incubating females that spend most of their time in the burrow during incubation. Our results suggest that depth is an important consideration when installing artificial burrows for Burrowing Owls. However, additional study is needed to determine the possible effects of burrow depth on reproductive success and on possible tradeoffs between the effects of burrow depth on optimal temperature and other factors, such as minimizing the risk of nest predation.     

Assessing the usefulness of prostaglandin E2 (Cervidil) for transcervical artificial insemination in ewes

The underlying theme of this study involved the evaluation of the dilatory effects of prostaglandin E₂ on the ovine cervix and thus the assessment of its potential applicability to transcervical artificial insemination (TCAI) in ewes. A novel method of prostaglandin E₂ administration (controlled slow-release vaginal inserts) was examined, and the practical implications of this approach including cervical penetrability and posttreatment pregnancy rates were evaluated. The Guelph method of TCAI was performed during the seasonal anestrus (n = 40) and the breeding season (n = 40) on multiparous Rideau Arcott × Polled Dorset ewes, with or without the pretreatment with Cervidil (for a duration of 12 hours or 24 hours before TCAI). Cervical penetration rates averaged 82.5% (66 of 80), and they varied neither (P > 0.05) between the two seasons nor between Cervidil-treated ewes and their respective controls. Cervidil priming significantly reduced the total time required for TCAI during the breeding season in comparison with controls (54 vs. 98 seconds), especially after the 24-hour exposure (38 vs. 108 seconds). The time taken to traverse the uterine cervix was negatively correlated (P < 0.05) with the breed (percentage of Rideau Arcott genotype) and lifetime lamb production in seasonally anestrous ewes. Four out of 36 (11%) successfully penetrated ewes in the breeding season (three ewes allocated to the 12-hour control group and one ewe that had received Cervidil for 12 hours) became pregnant and carried the lambs to term. Vaginal mucus impedance at TCAI was significantly and positively correlated with the total time required to complete the procedure in cyclic ewes, and the negative correlation between vaginal mucus impedance and total time values at the time of controlled intravaginal drug release device removal approached to significance in anestrous ewes. The present results indicate a moderate benefit of using Cervidil for inducing cervical dilation before TCAI in ewes, mainly in the breeding season. The specific reason(s) for impaired fertility after the TCAI using frozen–thawed ram semen remains to be elucidated.     

A rapid method for the detection of tryptophanase in anaerobic bacteria

A total of 633 anaerobic bacteria were examined for tryptophanase production using a rapid method which distinguishes within 5 to 180 minutes between anaerobes that contain tryptophanase and those that do not. Of the 196 tryptophanase-positive isolates tested, 99% showed tryptophanase activity within 2 hours as compared with 94.4% in 24 hours by a conventional method. A total of 299 tryptophanase-negative organisms were tested. Ninety three percent of these remained negative after 24 hours as compared with 95.3% when tested with a 24-h conventional method. Additional information was obtained on the sensitivity of this test and the time-dependent production of indole by tryptophanase.     

长爪沙鼠体蚤和巢蚤数量研究

1982～1996年对内蒙古自治区鄂托克前旗长爪沙鼠Meriones unguiculatus体蚤和巢蚤的数量进行了调查和分析,得到如下结果。获体蚤15种,同型客蚤指名亚种Xenopsylla conformis conformls (50.8%) 和秃病蚤蒙冀亚种Nosopsyllus laveiceps kuzenkovi (40.6%)为优势种。获巢蚤15种,秃病蚤蒙冀亚种(74.3%)为优势种;盔状新蚤Neopsylla galea (11.9%)和叶状切唇蚤突高亚种Coptopsyllus lamelliferardua (8.1%)为常见种。年巢蚤指数的均值是年体蚤指数的6.92倍。体蚤指数与巢蚤指数不相关(P>0,05),体染蚤率与巢染蚤率不相关(P>0.05)。不同年份 的体蚤和巢蚤多样性比较稳定。连续两年春季或秋季秃病蚤巢蚤指数大于10只后,可能流行动物鼠疫。     

Changes in power assessed by the Wingate Anaerobic Test following downhill running

Few studies have examined the effects of eccentric exercise-induced muscle damage on power despite power being a key performance variable in a number of sporting events. The aim of this study was to examine changes in anaerobic power (30-second Wingate Test), isometric strength of the knee extensors and flexors, muscle soreness, and plasma creatine kinase (CK) activity following downhill running. Eight men performed a 40-minute downhill (-7%) run on a treadmill, and measurements were taken on 6 occasions (2 baseline and 0.5, 24, 72, and 120 hours postrun). A second group of men (n = 5) had the measurements taken on 6 occasions without downhill running and served as a control group. A repeated measures analysis of variance revealed no significant changes in any measures across time for the control group. Following downhill running, significant (p < 0.05) decreases in strength (0.5-24 hours), and significant increases in muscle soreness (0.5-72 hours) and plasma CK activity (0.5-120 hours) were observed. A significant decrease in peak and average power (approximately 5%) was evident only 0.5 hours postrun, and the decrease was smaller in magnitude than that of strength (approximately 15%). These results suggest that power is less affected than strength after eccentric exercise, and the effect of reduced power on sport performance seems negligible.     

Burrow limitations and group living in the communally rearing rodent, Octodon degus

Group living is thought to evolve whenever individuals attain a net fitness advantage due to reduced predation risk or enhanced foraging efficiency, but also when individuals are forced to remain in groups, which often occurs during high-density conditions due to limitations of critical resources for independent breeding. The influence of ecological limitations on sociality has been studied little in species in which reproduction is more evenly shared among group members. Previous studies in the caviomorph rodent Octodon degus (a New World hystricognath) revealed no evidence that group living confers an advantage and suggest that burrow limitations influence formation of social groups. Our objective was to examine the relevance of ecological limitations on sociality in these rodents. Our 4-year study revealed no association between degu density and use of burrow systems. The frequency with which burrow systems were used by degus was not related to the quality of these structures; only in 1 of the 4 years did the frequency of burrow use decrease with decreasing abundance of food. Neither the number of females per group nor total group size (related measures of degu sociality) changed with yearly density of degus. Although the number of males within social groups was lower in 2008, this variation was not related clearly to varying density. The percentage of females in social groups that bred was close to 99% and did not change across years of varying density. Our results suggest that sociality in degus is not the consequence of burrow limitations during breeding. Whether habitat limitations contribute to variation in vertebrate social systems is discussed.     

Foraging behavior of golden hamsters (<Emphasis Type="Italic">Mesocricetus auratus</Emphasis>) in the wild

Foraging theory posits that animals should maximize energy gains while minimizing risks, the largest of which is usually predation. For small burrowing mammals the best measure of risk avoidance may be the time spent in the burrow, although this measure is rarely examined. During the spring of 2005 and 2006 we recorded the foraging behavior of female golden hamsters in their natural habitat in southern Turkey. Data were collected with a data logger and by direct observations. Female golden hamsters averaged 64 min per day above ground in a series of foraging trips with a mean duration of 5.5 min. Two nursing females increased their time out of the burrow by a factor of 6–8 times over the course of 16 days by increasing both the number of trips and the length of each trip. These results show that hamsters spend little time out of the burrow, thus minimizing risk, but they also show that time spent out of the burrow is related to the energy needs of the hamsters; lactating females with high energy needs exposed themselves to much greater risk than did non-lactating females.     

Alteration of burrow‐related behaviour of the norway lobster,nephrops norvegicus during infection by the parasitic dinoflagellate hematodinium

This study has used time‐lapse video recordings to analyze the burrow‐related behaviour of N. norvegicus under a 12 h light: dark regime in aquarium conditions, and compared this with the behaviour of lobsters infected by the parasitic dinoflagellate Hematodinium. Uninfected lobsters performed a higher number of burrow departures, of longer duration, during the hours of darkness than during the light. Infected lobsters performed a relatively constant number of departures of similar‐duration in the light and the dark periods. However, the mean number of departures per day performed by infected lobsters (70 day^‐1) was more than double that of uninfected lobsters (30.1 day^‐1), while the mean duration of burrow departures performed by infected lobsters (258.5s departure^‐1) was more than six times greater than in uninfected lobsters (38.7s ? departure^‐1). This led to a more than ten‐times increase (from 1.7 to 19.4%) in the percentage of the day spent out of the burrow by infected lobsters. This altered burrow‐related behaviour could be due to the nutritional demands of the parasites on infected lobsters, causing an increased requirement to forage, or alternatively to a ‘functional hypoxia’, due to the additional respiratory demands of the parasite, causing the host to emerge from the burrow onto the sediment surface to seek oxygen. Implications for the increased time spent out of the burrow are discussed in relation to availability of infected lobsters by trawlers and predators, and to the use of infection prevalence data from trawl‐caught samples in stock assessment models for N. norvegicus.