bluuebunny/crossref_metadata_2025 huggingface dataset:
The biology ofEuryattussp. indet., a web‐building jumping spider (Araneae, Salticidae) from Queensland: utilization of silk, predatory behaviour and intraspecific interactions
Authors: Jackson Robert R.
Published: September 2010

The biology of an aberrant saltioid spider,EuryattusThorell sp. indet., is described from observations in a Queensland rain forest and the laboratory. Pronounced morphological and behavioural changes occur during post‐embryological development. Juveniles spin webs, but adult females make ‘suspension nests’ by suspending a curled‐up leaf by heavy guylines from a rock ledge or vegetation. Adult males spin neither webs nor suspension nests. Females oviposit inside their suspension nests, but if denied access to leaves for suspension, they spin and oviposit in webs similar to those spun by juveniles. The flat, papery egg sacs ofEuryattusare atypical for a salticid, being more like the egg sacs of many of the Gnaphosidae. Intraspecific display behaviour has characteristics in common with typical salticids, but also includes unique features. Male courtship includes vibratory displays performed on the surface of the suspended leaf. Mating occurs inside the curled‐up leaf. Males co‐habit with sub‐adult females in suspension nests. Females take over suspension nests of other females and eat each other's eggs. Normal locomotion, intraspecific interactions, and predatory behaviour are characterized by frequent leaping.Euryattusroutinely makes long and accurate leaps on to prey, including flying insects intercepted in mid‐air and spiders and insects located in alien webs. The phylogenetic implications of the unusual characteristics ofEuryattusare considered.
The biology of Simaetha paetula and S. thoracica, web‐building jumping spiders (Araneae, Salticidae) from Queensland: co‐habitation with social spiders, utilization of silk, predatory behaviour and intraspecific interactions
Authors: Jackson Robert R.
Published: September 2010

The biology of two aberrant species of salticid spiders is described from observations in tropical Queensland and in the laboratory. Typical salticids are cursorial hunting spiders that do not build prey‐catching webs, although they frequently build enclosing, tubular nests. Simaetha paetula (Kerserling) and S. thoracica Thorell, however, are both cursorial predators that build nests and spiders that build large prey‐catching webs. Nests and webs may be built alone or incorporated into the same structure. Adults, more often than juveniles, build isolated tubular nests. Juveniles, more often than adults, build webs without tubes. Nest‐webs are built most often on leaves and stems of plants, and the leaves are sometimes fastened to stems by strong silk clamps. Intraspecific interactions of S. paetula occur both at and away from nest‐webs. Away from nest‐webs, visual displays occur, but both visual and vibratory displays are important at nest‐webs. A repertoire of discrete displays occurs in both contexts. One prevalent display, clawing, is apparently multi‐channel: visual when the spiders are distant from each other and away from nest‐webs; tactile or chemotactic after the spiders come into contact with each other; and vibratory when they are at nest‐webs. During inter‐male interactions, displays occur that are unusually stereotyped for a salticid and require an unusual degree of co‐ordination of the movements of the two spiders. Males co‐habit in nest‐webs with sub‐adult females and mate when the female matures. Two different copulatory postures are routinely adopted, one of which is aberrant for salticids. Cannibalism is frequent, but the hypothesis that cannibalism reduction has been important in the evolution of display behaviour is not supported. Species of Simaetha Thorell often live within the colonies of the social spider Badumna Candida (L. Koch) as a kleptoparasite, gleaning insects from the edges of the alien webs and incorporating its own nest‐webs within the alien communal web. Although vulnerable to the glue on the social spider webs, Simaetha has behavioural specializations that enable it to avoid becoming prey of the social spiders. The biology of Simaetha is discussed in relation to salticid evolution.
A comparison of the molar efficiency of two insect‐eating mammals
Authors: Moore S. J. , Sanson G. D.
Published: September 2010

The extent to which the different molar morphologies of two similar‐sized mammals, Petaurus breviceps (sugar glider) and Dasyuroides byrnei (kowari), could affect the digestion of larval insect nitrogen was investigated. Nitrogen digestibility of Tenebrio larvae treated with a proteolytic enzyme (trypsin) increased with decreasing larval piece size. However, it was found that the molars of P. breviceps, with their minimal shearing capacity compared with D. byrnei, can only compress rather than finely comminute Tenebrio larvae. As a result, P. breviceps have less efficient nitrogen digestibility than D. byrnei whose shearing molars can finely comminute larvae. Petaurus breviceps molars are inefficient at breaking down insects possibly because of functional constraints, where the molars must perform several different tasks with competing morphological demands, or because of phylogenetic constraints.
Neophobia and its effect on the macro‐structure and micro‐structure of feeding in wild brown rats (Rattus norvegicus)
Authors: Brunton Clair F. A.
Published: September 2010

The effect of neophobia (fear of novelty) on feeding behaviour was examined in two groups of captive wild rats fed ad libitum. Different individuals employed different feeding patterns in response to novelty despite the absence of social and ecological constraints. The prevalent feeding pattern was to delay eating from a novel bowl several nights after it was introduced and, in general, novel food was sampled towards the end of a night. Systematic relationships (prandial correlations) were revealed in the meal pattern data which were consistent with the prediction that post‐prandial correlations (controlled regular feeding bouts) are more likely in predictable environments. A large proportion of the individuals exhibited no prandial relationships which correlated with high levels of neophobia supporting the hypothesis that highly neophobic individuals are less able to regulate their feeding in the presence of novelty.
Age assessment in infant crab‐eating monkeys (Macaca fascicularis) based on tooth development
Authors: Ostyn J. M. , Maltha J. C. , van der Linden F. P. G. M.
Published: September 2010

Tooth development was studied in 13 Macaca fascicularis monkeys with known dates of birth. Regular intra‐oral examination was carried out and standardized lateral radiographs were collected from 27 until 150 weeks of age under general anaesthesia.

Three stages of tooth development were determined radiographically: onset of crypt formation, onset of mineralization, and crown completion. A fourth stage, the emergence, was determined clinically. Developmental stages were recorded for six mandibular and five maxillary teeth.

The ages of emergence of the permanent teeth and the developmental stages of the third molars showed the largest variation. A significant sex difference with earlier maturation in males was found for the start of crypt formation of the maxillary permanent canines and the maxillary second premolars, and for the start of mineralization of the maxillary permanent canines.

The data provide a tool by which chronological age can be assessed of Macaca fascicularis monkeys between 30 and 80 weeks of age. Owing to an interphase of about one year without significant developmental features in the dentition, age assessment based on tooth development cannot be performed from about 80 to 130 weeks of age. Age assessments are possible for the period between 130 and 150 weeks of age. However, in this period the reliability of the data is lower due to larger time intervals and standard deviations.
The distribution and number of the skin sense organs of agamid, iguanid and gekkonid lizards
Authors: Matveyeva T. N. , Ananjeva N. B.
Published: September 2010

The topography and numerical distribution of the skin receptors in 29 lizard species including 18 agamids, eight iguanids and three gekkonids, are compared and contrasted. There are no marked differences in the number of receptors in the dorsal and ventral surfaces of the body in the different groups. The maximal density of the receptors occurs on the head and decreases in the caudal direction.

Iguanids and gekkonids have 5–6 times more receptors than agamids. Agamids Gonocephalus grandis from S.E. Asia, Pogona barbata, Diporiphora bilineata from Australia and Ceratophora tennentii from Sri‐Lanka, however, are distinguished by their high density of receptors, especially on the head. Species of Physignathus are similar to iguanids in this way. The agamid Phrynocephalus mystaceus shows considerable differences, in receptor number, from other species of this genus. There is a high density of receptors on the caudal scales of the Madagascan iguanid Oplurus, and a similar high density of receptors on the ventral surface of the gecko Teratoscincus scincus.
Effect of photoperiod and ambient temperature on activity patterns and body weight cycles of mountain pygmy‐possums, Burramys parvus (Marsupialia)
Authors: Körtner G. , Geiser F.
Published: September 2010

The mountain pygmy‐possum Burramys parvus shows strong seasonal rhythms of reproduction and activity in summer, pre‐hibernation fattening in autumn and hibernation in winter. We investigated whether photoperiod or air temperature (Ta) or interactions of these environmental factors influence activity patterns, fattening and onset of hibernation. In January 1993, 10 Burramys held under long photoperiod were divided into two groups. One group was maintained under the previous long photoperiod (LD 14.5:9.5; n= 5), the other was transferred to short photoperiod (LD 9.5:14.5; n= 5). The Ta was reduced in steps lasting at least one month from 12 to 8 to 4 and to 2°C. All individuals showed pronounced daily activity rhythms and were mainly nocturnal. Individuals under short photoperiod maintained their nocturnal activity pattern irrespective of Ta. In contrast, most individuals under long photoperiod at Ta 4 and 2°C temporarily showed a free‐running activity rhythm and began their activity period during the day. Body weight and total daily activity were negatively correlated. Individuals with low body weight (<50g) generally were more active and showed longer activity periods than heavy animals. Under both photoperiods these lean individuals often extended their activity periods into the light phase. While in the first year after capture all animals showed pre‐hibernation fattening and hibernation, a second body mass cycle was observed in only five individuals and this was independent of Ta and photoperiod. However, total daily activity in these individuals decreased with increasing body weight. Our study shows that photoperiod has little influence on seasonal changes of activity, body weight and hibernation of Burramys. Low Ta has some effect on activity patterns of Burramys held under long photoperiod. Body weight and activity of Burramys were interrelated suggesting that pre‐hibernation fattening occurs during a time of reduced activity and thus low energy expenditure.
The chemical composition of montane plants and its influence on the diet of the large mammalian herbivores in the Pare National des Volcans, Rwanda
Authors: Plumptre A. J.
Published: September 2010

The diets of five large mammalian herbivores in the Pare National des Volcans, a tropical montane forest, were determined using microhistological analysis of faecal material. Correction factors were used to calculate the biomass intake from the relative areas of leaf cuticle found in the faeces. Dietary nitrogen was calculated from the biomass intake obtained in the faecal analysis. This compared well with faecal nitrogen values corrected for dietary intake using equations from the literature. Both measures indicated that each of the five herbivores was obtaining a nitrogen‐rich diet. Preferences for food plants were calculated using Manly's alpha as a measure. Nutrient content and other measures of dietary quality of the plants were determined and a multiple regression analysis used to determine which were important for the dietary intake of each herbivore. Mountain gorillas showed a selection of digestible food plants whilst buffalo selected food plants that were not easily digested. Other than in vitro digestibility, none of the measures of dietary quality correlated with the intake of the herbivores. Dietary overlap between the species was significantly lower than expected overlap values calculated using Monte Carlo analyses of neutral models. It is suggested that nutrients were not limiting the populations of these five herbivores.
Small males emerge earlier than large males in Dawson's burrowing bee (Amegilla dawsoni) (Hymenoptera: Anthophorini)
Authors: Alcock J.
Published: September 2010

Females of Dawson's burrowing bee (Amegilla dawsoni) are receptive to the males as they emerge but have become unreceptive by the time they begin to nest. In addition, there is a single emergence period per year lasting about a month. These factors are predicted to lead to protandry and males of Dawson's burrowing bee do tend to emerge earlier in the annual flight season than females. Moreover, even during a single day, emerging males tend to precede females. The degree of protandry, however, is size‐dependent, with smaller males tending to precede larger ones, both over the course of the flight season and on any given day. Because small males are at a disadvantage in the fights that occur for females, the earlier emergence of minor males may be a sexually selected response that reduces the likelihood that they will be displaced from potential mates by larger rivals.
Predation by marine‐feeding otters (Lutra lutra) in south‐west Portugal in relation to fluctuating food resources
Authors: Beja Pedro Rui
Published: September 2010

Patterns of predation by otters (Lutra lutra) inhabiting the Portuguese south‐west rocky coast, were inferred from the analysis of 757 spraints collected along a 5‐km stretch of shore, from November 1990 to October 1993. Undigested remains were identified, counted and measured; the length and weight of ingested prey was estimated from regression equations. Monthly fluctuations in diet were compared to changes in the abundance of the primary prey species along the coast. The most commonly taken fish species had median lengths between 6.7cm and 15.0cm, and median weights between 3.5 g and 34.2g. Corkwing wrasse dominated the diet in terms of biomass (51.6%), and was the most important prey in terms of numbers (22.6%). Gobies (19.4%), Valenciennes' blennies (15.0%), shannies (1 1.4%), crayfish (7.2%), and shore rocklings (4.1%) were other numerically important prey. The contribution in biomass of gobies (14.5%), shore rocklings (6.7%) and conger eels (5.5%) was also significant. The dominant prey species and sizes in the diet were consistent over the years. From late winter to early spring the diet was numerically dominated by corkwing wrasse and gobies, whereas for the rest of the year shannies, Valenciennes' blennies and crayfish were also important. The contribution of these last species in biomass was small at all times of the year, and the corkwing wrasse was always the dominant prey. Prey was twice as heavy in winter as in spring. There was close correspondence between seasonal variation in diet and fluctuations in the abundance of the primary prey along the coast, but most dietary variation could be accounted for simply by fluctuations in the abundance of corkwing wrasse. In south‐west Portugal, the most important food resource for otters seems to be the corkwing wrasse, probably because they are large and easy to catch. Corkwing wrasse are also exploited by local fishermen, and the possibility of competition between otters and humans should be investigated.
Community structure and habitat use of small mammals in grasslands of different successional age
Authors: Churchfield S. , Hollier J. , Brown V. K.
Published: September 2010

The use of habitat by eight species of small mammals was investigated by live‐trapping and markrecapture techniques in a series of eight grassland plots of different successional age, ranging from 11 months to 10 years at the start of the study, in southern England. Vegetation composition and structure in the grassland plots was investigated by point quadrat and biomass methods. Species richness ranged from 5–6 per plot. The harvest mouse,Micromys minutus, was a relative specialist that dominated the ruderal stage with its abundant annual and perennial forhs, and was absent from the mid‐successional stage. The wood mouse,Apodemus sylvaticus, was also a relative specialist, but dominated the opposite end of the successional gradient (the mid‐successional stage, with its small trees and shrubs), and occurred infrequently on the ruderal plot. The common shrew,Sorex araneus, pygmy shrew, S.minutusand field vole,Microtus agrestiswere relative generalists with no clear habitat preferences. S.araneuswas numerically dominant on most plots and was abundant even on the ruderal plot. The midsuccessional stage sustained the greatest total number of small mammals, but the ruderal plot was also well populated. Niche overlap was greatest between the shrews and least betweenA. sylvaticus and M. minutus. Despite some preferences for mid‐successional stages, all species were rapid colonizers of the ruderal plot: first to be captured regularly wereM. minutus and A. sylvaticus, followed by the shrews andM. agrestis, all within 1–2 years of establishment of the plot.
Localization of an extracerebral NSV‐ganglion in the cephalopod, Sepia officinalis
Authors: Marschinke Antje
Published: September 2010

The neurosecretory system of the vena cava (NSV) of Sepia officinalis contacts the palliovisceral lobe with some axons that run parallel to the visceral nerves. Distal to the palliovisceral lobe the NSV‐ system widens to form a hitherto unknown extracerebral ganglion containing approximately 4200 perikarya. This is regarded as the primary origin of neurotransmitters. Distal to this nucleus area the volume and the number of cell bodies in the NSV‐system is reduced. It contains neurosecretory nerve cells, two glial cell types, large cell accumulations, connective tissue and capillaries. Histochemical, immunohisto‐ and immunocytochemical examinations show the existence of catecholamines, and the coexistence of serotonin and FMRFamide in the NSV‐System. A HPLC analysis differentiated between dopamine, noradrenaline, and adrenaline.
Body weight as an indication of density‐dependent population regulation in badgers (Meles meles) at Woodchester Park, Gloucestershire
Authors: Rogers L. M. , Cheeseman C. L. , Langton S.
Published: September 2010

The body weights of badgers were examined to look for density‐dependent effects of the increase in group size at Woodchester Park, Gloucestershire. The weight of badgers in 21 groups were studied from 1978–1993. A significant negative relationship was found between weight and group size in breeding adult females in autumn and winter, and adult males in summer, such that increase in group size caused a decrease in weight. However, these relationships were affected by year‐to‐year changes and random variation, and overall there was no downward trend in body weight. The existence of density‐dependent effects on badger populations at high density was consistent with previous findings
A mass stranding of white‐sided dolphins (Lagenorhynchus acutus) in Ireland: biological and pathological studies
Authors: Rogan E. , Baker J. R. , Jepson P. D. , Berrow S. , Kiely O.
Published: September 2010

We give details of the biological and pathological findings in a mass stranding of 19 white‐sided dolphins on the west coast of Ireland. The pod consisted of adults and calves; no juveniles were present. The calf of a recently parturient female was not found. The presence of small foetuses suggested that mating took place in late August or early September. The largest and oldest male was severely diseased but the remainder of the pod were in good health although some minor lesions were found. The site where the animals came ashore was compatible with the geomagnetic theory of mass strandings.
Food selection by European roe deer (Capreolus capreolus): effects of plant chemistry, and consequences for the nutritional value of their diets
Authors: Tixier H. , Duncan P. , Scehovic J. , Yant A. , Gleizes M. , Lila M.
Published: September 2010

We describe food selection by roe deer (Capreolus capreolus) in relation to the food quality of the plants available (the concentrations of fibres, sugars, crude protein, and of phenolics and terpenes). Seven tame roe deer feeding in an oak‐beech woodland edge used the majority (80‐94%) of the plant species available: they were therefore generalist feeders. However, they preferred only a small number of plant species in the different seasons: ivy (Hedera helix) in winter and autumn, dogwood (Cornus spp.) in summer, hornbeam (Curpinus betulus), hawthom (Crataegus spp.) and bluebells (Hyacinthoides non‐scripta) in spring. No preference or avoidance could be demonstrated for 74‐85% of the available species, but 7‐12 species were avoided according to the season. Though the avoided species were sometimes common, they never comprised an important part of the diet. In contrast, the preferred species made up only 4‐13% of the available green matter but composed a large part of the diet (22‐49%). Although generalists, the roe deer were therefore also highly selective feeders. The use of the different plant species was influenced by their availability, but to a different extent in the different seasons. Use of the plant species correlated negatively with the fibre content, as predicted from the digestive morphology of this concentrate selector. Preference/avoidance was related to the concentrations of soluble sugars, but not the crude protein content. Contrary to expectation, the roe deer preferred plants with a high concentration of protein‐binding phenolics, suggesting that this deer has specific mechanisms for de‐activating these compounds. Among the nutritional consequences of the feeding strategy of roe were a 17‐35% higher soluble sugar content of the diet compared with the available green plant tissues, and an even greater increase in the phenolics. The crude protein contents and the dry matter digestibility of the diets tended to be slightly higher, and the fibre contents were lower, than those of the available green plant tissues.
A Comparison of the diet and distribution of southern river otter (Lutra provocax) and mink (Mustela vison) in Southern Chile
Authors: Medina Gonzalo
Published: September 2010

In Chile, between latitudes 39d̀S and 43d̀30'S, southern river otter (Lutra provocax) and introduced mink (Mustela vison) scats were collected. Mink sign was recorded in 29% of the aquatic habitat where otter sign was found. Sixty‐eight per cent of mink scats were collected at otter rest sites. A significant difference between the diets and low percentage of habitat use overlap of the two species (5‐22%) suggest that, in Chile, river otter and mink coexist with little competition for space or food. There are no data supporting a relationship between the introduction of mink and the decline of southern river otters.
The influence of flocking on the foraging behaviour of the chough (Pyrrhocorax pyrrhocorax) and the Alpine chough (P. graculus) coexisting in the Alps
Authors: Rolando A. , Laiolo P. , Formica M.
Published: September 2010

We studied the flocking and foraging behaviour of the chough Pyrrhocorax pyrrhocorax and the Alpine chough P. gruculus coexisting in the south‐western Italian Alps in order to evaluate the costs and benefits of foraging in single‐ and mixed‐species flocks.

In the single‐species context, flock size significantly affected the foraging behaviour of the Alpine chough; in larger flocks, the birds stayed for a shorter time in a patch and fed more quickly than in smaller flocks. Flock size did not significantly affect the foraging behaviour of the chough, probably because of the small number of individuals per flock.

The propensity for mixed‐species flocking was rather low. The observed frequencies of single‐species flocks of choughs and Alpine choughs were significantly higher than those expected on the basis of random flocking, whereas the observed frequencies of mixed‐species flocks of the two species were lower than those expected. The stay times became significantly shorter for the chough in the presence of the Alpine chough. Moreover, feeding rates of the Alpine chough were significantly lower in the presence of the dominant chough.

The present study does not confirm the hypothetical foraging advantages of flocking. In single‐species flocks, the benefits for the Alpine chough (higher feeding rates in larger flocks) were roughly compensated by the costs (shorter stay times in larger flocks), whereas the chough apparently neither gained benefits nor endured costs.

In mixed‐species flocks, the Alpine chough sustained costs due to a reduction of feeding rates and the chough suffered costs due to a reduction of stay times. Hence, on average, single‐species flocking gives no evident foraging advantages to either the chough or the Alpine chough, whereas mixed‐species flocking provides some disadvantages for both species.
Tracking and the interpretation of spoor: a scientifically sound method in ecology
Authors: Stander P.E. , Ghau II. , Tsisaba D. , OMA II. , VI |.|
Published: September 2010

Methods of studying wildlife are often restricted by habitat. Tracking, the reconstruction of activity from the spoor of animals, is an age‐old technique that is still frequently used by modern‐day hunter/gatherer communities. Although previously used in behavioural studies, tracking has not been tested for its scientific merit. In this paper, we provide data towards such a description by first testing the reliability of tracking, and second attempting to measure the techniques of tracking. In a test for accuracy, the Ju/'Hoan San team was correct in most (98% of 569) spoor reconstructions. Most significant of these were the correct identification of individually known animals and the reconstruction of complex behaviour from spoor. Measurements of the spoor of different species and age/sex groups in some species showed significant differences. Variation in different soil conditions, however, affected spoor measurements so that subtle differences between individually known animals could not be measured. Measurements of the spacing distances and placement of feet during different gaits gave statistical and schematic values to indicate some of the techniques used by trackers during the reconstruction of behaviour. Indigenous peoples, such as the Ju/'Hoan, have an in‐depth knowledge of nature. Collaboration between western science and traditional knowledge could greatly benefit studies in behaviour and wildlife.
The ecology of asociality in Namibian leopards
Authors: Stander P. E. , Haden P. J. , Kaqece II. , Ghau II.
Published: September 2010

Data on the ecology of leopards (Panthera pardus) from north‐eastern Namibia are presented and discussed in terms of the possible costs and benefits of solitary behaviour. In an area of low leopard density, where individuals lived alone, both males and females occupied large home ranges,(♂= 210‐1164km2, ♀= 183‐194km2). Despite resource and reproductive advantages in maintaining exclusive ranges, the degree of range overlap both between and within sexes was substantial. Average overlap between males was 46% and between females 35%. The cost of dispersal appeared high as all three marked sub‐adults died, and most recorded mortalities were of sub‐adults. Females with dependent young showed a significant increase in per capita food intake compared to single females and males. Higher foraging success by females with cubs was revealed through two energy expenditure parameters (kg/km travelled/day and kg/hunt/day). Differential food intake between females with cubs, single females and males can be explained partly by differences in day ranges, body size and costs of parental care. Females shared 27% of their food with cubs and the costs of sharing food does not appear as high as previously suggested. Inter‐specific competition over food and the defence of carcasses is suggested as an important cost to group living. Leopard kills were visited by other large carnivores (12%) but food loss was minimal (2%). Leopards successfully avoided conflict with inter‐specific competitors by dragging and hiding kills in thick vegetation. We argue that solitary and secretive behaviour enables leopards to avoid the costs of defending carcasses against larger and gregarious carnivores.
Distinguishing between the hair fibres of the rabbit and the mountain hare in scats of the red fox
Authors: Wolfe Alan , Long A. M.
Published: September 2010

Irish mountain hare and rabbit hair fibres were examined for differences in microstructure. Obvious and significant differences were found in the widths of the cortex in the shield and shaft regions of the dorsal guard hairs. Other less obvious differences were also noted in scale overlap and patterns. These findings were applied in the examination of a small number of fox scats collected from a coastal grassland habitat. Mammals were by far the most important prey item of the fox; rabbit remains were present in 83% of scats examined. Hare remains were present in 15% of the scats with significantly more hare remains occurring in the scats during winter.
Insectivory in captive Livingstone's and Rodrigues fruit bats Pteropus livingstonii and P. rodricensis (Chiroptera: Pteropodidae): a behavioural adaptation for obtaining protein
Authors: Courts S. E.
Published: September 2010

Captive Pteropus livingstonii and P. rodricensis were observed actively to catch and eat insects. Both species adopt the same technique to trap flying insects, using their wings to envelop them. The spontaneity of the response indicates that it is not an artefact of captivity. The behaviour was observed in captive‐bred P. rodricensis which had no prior access to insects, suggesting that it is also innate. A higher rate of successful captures was recorded for an older, wild caught P. livingstonii female, indicating that the effectiveness of the technique used may improve with age. Significant differences in the amount of time spent catching insects by males and females were evident in this species. This study supports suggestions that insects are eaten by some megachiopterans in order to supplement their protein intake.
Activity patterns and time budgets of Andean bears (Tremarctos ornatus) in the Apolobamba Range of Bolivia
Authors: Paisley S. , Garshelis D. L.
Published: September 2010

Activity patterns and time budgets of Andean (or spectacled) bearsTremarctos ornatuswere examined in a high‐altitude (3000–4000 m) mixed grassland–cloud forest environment in the Apolobamba Range of northern Bolivia. Two males were captured, fitted with motion‐sensitive radio‐collars and monitored during 1998–1999. As with many cryptic species, Andean bears had been assumed to be nocturnal, but both bears in our study were diurnal. Activity generally began around 06:00 h (near sunrise) and lasted until 20:00–21:00 h (sunset), with reduced activity during 11:00–14:00 h. Bears rested for 1–2 h during daylight hours, generally in two or more brief periods, and slept 9–12 h at night. Few differences were observed between activity patterns or time budgets during the dry season (April–September) and rainy season (October–March). Averaged across all hours and both seasons, each bear was active 53% of the time. This level of activity was similar to that of other species of bears (generally 50–60%), suggesting either that Andean bears are well adapted to living in an environment where fibrous bromeliads constitute the bulk of their diet or that our two study bears could subsist there only because they were both small‐sized individuals.
Food availability and annual migration of the straw‐colored fruit bat (Eidolon helvum)
Authors: Richter H. V. , Cumming G. S.
Published: September 2010

Animal migrations offer a unique opportunity for developing and testing hypotheses about the ecological requirements of different species and the tradeoffs that they make between conflicting life‐history demands. There has been relatively little research into the causes and consequences of migrations by fruit bats, despite their potential significance for pollination and seed dispersal. We assessed the causes of one of the most spectacular migrations of fruit bats known: the annual influx of an estimated 5–10 million E. helvum into Kasanka National Park in Zambia. We tested several predictions based on the hypothesis that E. helvum migrates to exploit seasonal variations in food supply opportunistically. Phenological data, feeding observations and monitoring of fruit bat movements provided the first quantitative evidence in support of the hypothesis that the migration of E. helvum in Zambia is driven by food supply. The E. helvum colony exhibited several surprising behaviors, including a tendency for migratory satellite colonies to aggregate, rather than to disperse, during the time of peak food production, and a tendency to fly well beyond the most immediate food sources when foraging. Alternative hypotheses to explain the E. helvum migration were not supported, but further research is needed to clarify the results of this preliminary study. Both the size of the colony and its potential for large‐scale movements suggest that this bat may play an important economic and ecological role over a significant portion of sub‐Saharan Africa. Information is still lacking about migration routes, food sources, habitat requirements and the role of migration in disease transmission between colonies of E. helvum.
A morphometric assessment of geographical variation and subspecies in impala
Authors: Bastos‐Silveira C. , Lister A. M.
Published: September 2010

The single species of Aepyceros, Aepyceros melampus (impala), is native to central and southern Africa, from Uganda to South Africa. It inhabits open woodlands, sandy bush country and acacia savannah. This study tested the morphological and geographical variation among specimens of impala and their possible relation with described subspecies. Nineteen skull and horn measurements were taken. A multivariate analysis was used and size and shape were explored. Facial coat patterns were also coded. The results supported four out of five traditionally described subspecies: Aepyceros melampus petersi from Angola/Namibia, Aepyceros melampus melampus from South Africa, Aepyceros melampus suara from East Africa and Aepyceros melampus johnstoni from Zambia and Malawi. We consider Aepyceros melampus rendilis to be a synonym of suara. A revised synopsis is suggested, with comments on the geographical ranges of the subspecies. Skull dimensions also allowed us to estimate the geographical origin and subspecies of some individuals of unknown provenance. Coat patterns showed no clear relation with subspecies or geographic location, with the exception of A. m. petersi.
SEEDS AND SEED BANKS
Authors: THOMPSON K.
Published: September 2010

Summary

The involvement of four factors (life history, predation, possession of a persistent seed bank and seedling establishment) in the evolution of seed size in flowering plants is discussed. Among herbacaeous plants, biennials seem to have larger seeds than annuals and perennials, a difference which may explain the capacity of some biennials to establish in closed vegetation. In many species, small seeds may have evolved at least partly as a defence against predators. Seeds < 3 mg have some immunity from vertebrate predators but much smaller seeds are consumed by invertebrates. Burial reduces or eliminates most predation by invertebrates.

Possession of a persistent seed bank is associated with small, compact, smooth seeds with exacting requirements for germination. Seeds of species which lack seed banks are larger, frequently long or flat, and often have hairs or awns and lax requirements for germination. The evolution of the former group is often intimately connected with the preferences of earthworms. Burial facilitates anchorage of seedlings.

In closed herbaceous vegetation, establishment of seedlings seems to be dependent on a low rate of exhaustion of seed reserves achieved by a large seed, low relative growth rate of seedlings or both. In many data sets, seed size and seedling growth rate are negatively correlated, but the generality of the correlation is in doubt. The large seeds of many herbs, shrubs and trees of woodland are suspected to be of critical importance in seedling emergence through tree litter.
CLIMATIC TOLERANCE AND THE DISTRIBUTION OF PLANTS
Authors: GRACE J.
Published: September 2010

Summary

Boundaries to the distribution of life forms and species often coincide with isometric lines of climatological variables. Prominent examples of this phenomenon are the restriction of megaphanerophytes to areas where the mean temperature of the warmest month does not fall below about 10 °C, and the restriction of species within the British Isles to areas of specific summer or winter warmth. In the interpretation of these patterns, it is important to realise that the climate at plant surfaces may differ appreciably from that of the atmosphere as a whole, to an extent which depends on structural attributes of the vegetation. I n particular, chamaephytes experience a much higher surface temperature than phanerophytes when comparisons are made in bright sunlight and this contributes to their success in mountains. Temperatures of flowers may similarly be elevated. In the British Isles, temperatures in the summer months may be decisive in determining the success of many species, as physiological processes in C3‐plants display near‐linear relationships with temperatures in the range which prevails for most of the time. The life‐cycle of native plants responds to environmental cues in such a way as to synchronize the development of the plant with the succession of seasons. When species are transplanted to different phytogeographical zones, as in forestry and horticulture, they frequently fail because of asynchrony.
Nutrient limitation of the long term response of heather [Calluna vulgaris (L.) Hull] to CO2 enrichment
Authors: WOODIN S. , GRAHAM B. , KILLICK A. , SKIBA U. , CRESSER M.
Published: September 2010

summary

In a 27‐month CO2‐enrichment experiment, Calluna vulgaris plants were grown on peat obtained from an upland heath in NE Scotland and given a nutrient supply which mimicked that in precipitation in the area. Three CO2 concentrations were used; ambient, +100ppm and +200ppm. Calluna showed a negative growth response to increased CO2 over the first year of treatment and a positive response by the end of the experiment. Final above–ground biomass was greatest in the enriched CO2, treatments, showing an increase of 30 °0 in + 100ppmCO2. Determination of tissue nutrient concentration, and calculation of total nutrient uptake, demonstrated that nutrient uptake did not increase with increased growth, resulting in significant dilution of elements in leaf tissue. This suggests that, in its typical, nutrient poor habitats, the growth response of Calluna to CO2 will be limited by nutrient deficiency, and will reach a maximum with a relatively small increase in CO, concentration. Flowering was advanced and extremely prolific in +100 ppm CO2 grown plants, but the ecological significance of this is uncertain. The results highlight the need for long term studies of native species on their natural soils, using lower CO2 concentrations than the usual ‘double CO2’.
Spatial variation in ozone resistance of British populations of Plantago major L.
Authors: REILING K. , DAVISON A. W.
Published: September 2010

summary

The relative ozone resistance of samples from 28 British Plantago major L. populations, grown from seed, was measured by exposure to charcoal–filtered air or air containing 70 nl I−1 O3 (7 h d−1) over 2 wk. Mean relative growth rate (R) and the allometric root/shoot coefficient (K) were measured. Ozone resistance was expressed as Ores=Rozone/Rcontrol× 100.

There were substantial differences between the response of the populations to O3, and the degree of resistance was statistically related to O3 exposure indices and other environmental factors, notably the amount of summer sunshine. This implies that ozone concentrations in parts of Britain are sufficiently high to promote evolution of resistance but alternative explanations are also discussed. Overall, it is concluded that although our results tend to support the hypothesis that O3 resistance in P. major is related primarily to the O3 climate, the question of causation can only be established unequivocally by further experiments. Establishing whether there has been a change in gene frequency needs repeated observation of populations over time.

The significance of spatial variation in ozone resistance to the critical levels concept is discussed, particularly in relation to exposure indices.
Evidence for the de novo synthesis of Fructan by enzymes from higher plants: a Reappraisal of the SST/FFT model
Authors: JOHN CAIRNS ANDREW
Published: September 2010

For the following reasons, it is argued that the enzymological evidnce is insufficient to sustain the SST/FFT model for fructan systhesis. (i) The original model was speculative. It was formulated without in vitro evidence for the synthesis of inulin of degree of polymerization greater than 3 (DP >3), and without published evidence for the existence of a key enzyme (SST). The model is shown to be untestable in vitro. Subsequently, studies have not domonstrated the synthesis of inulin in vitro, except for trisaccharide. (ii) Most data cited in support of the model are concerned with the synthesis of the smallest fructans (trisaccharides) by crude enzyme extracts. Much of these data can be explained in terms of artifactual fructosyl trasfer by invertase, a common contaminant of plant enzyme preparations. (iii) There are few reports of the de novo enzymatic synthesis of fructan DP >3 in plants. Where it has been reported, it was eatalyzed by crude or partially purified enzymes. Hence the number and properties of the enzymes involved is not known, providing no evidence for distinct SST and FFT enzymes. (iv) Assays for FFT require preformed fructan substates. FFT transfers fructose between preformed fructan molecules without net synthesis of fructan. Hence measurement of FFT is not evidence for net fructan synthesis. (v) Invertase can mimic the FFT reaction. (vi) The enzymes of fructan biosynthesis have not been purified and characterized in any plant species. Where functional separation of SST and FFT activities has been achieved. Reconstitution experiments have not been performed demostrating de novo fructan synthesis by the recombined activities. (vi) The SST/FFT model explains the synthesis of the linear β‐2,1‐linked homologous series of fructans. The model is inadequate to explain the synthesis of other linkage types and branched fructans. (vii) There is no demonstration of the enzymatic de novo synthesis of the full complement of tissue fructan by SST/FFT or otherwise, for any plant species.

Although were is a substantial body of evidence which is consistent with the SST/FFT model, it is concluded that the hypothesis is flawed and that the enzymological data from all species do not validate the model. Enzyme systems from grasses are described which overcome some of these difficulties.
The kinetic analysis of fructan biosynthesis in excised leaves of Lolium temulentum L.
Authors: SIMS I.M. , MORGAN R. , POLLOCK C. J.
Published: September 2010

Excised leaves of Lolium temulentum L. were fed 1CO. at 99% isotopic abundance in order to study the kinetics of incorporation of photosynthetically fixed carbon into different fructans and to determine the pathways of synthesis between sucrose and high‐molecular‐weight fructan. Following 6 h exposure to CO2 of detached and illuminated leaves, analysis of the accumulation of I‐keatose, 6–kestose and neokestose, and of the pattern of labelling observed in these isomers, suggested that they were each formed directly from sucrose at different rates. Similarly, the data suggested thai the tetrasaccharide isomers were formed directly from their trisaccharide precursors. Changes in the concentration of 13C both in the total water‐soluble component of the leaves and the fructan pool after 20h exposure to 13Co2 suggested that there was a continual turnover of frunctosyl residues. The formation of trisaccharides From sucrose and subsequent frunctosyl transfer to oligo‐ and polysaccharides of progressively higher molecular weight was consistent with a direct precursor product relationship. The stable concenttation of sucrose observed in leaves between 14 h and 48 h after excision indicated that fructan metabolism in L. temulentum may serve to regulate the sucrose content of the tissue.
Yield advantage of a ‘slow‐’over a‘fast‐’respiring population of Lolium perenne cv. S23 depends on plant density
Authors: KRAUS EDWIN , AYDEMIR YILDIZ , DUIN SANDRA , KOLLÖFFEL CHRIS , LAMBERS HANS
Published: September 2010

Selected populations of Lolium perenne have previously been shown to have contrasting rates of mature leaf dark respiration and yield. Plants were now grown in high‐ and in tow‐density stands. We were able to reproduce the differences in yield for the high‐density‐grown plants. However the low‐density‐grown plants did not differ in yield and so (the correlation between respiration and yield is not apparent, It is concluded that the difference in respiration rate is not the most important factor determining yield with these populations.
Mustards, mustard oils and mycorrhizas
Authors: PAUL SCHREINER R. , KOIDE ROGER T.
Published: September 2010

Intact, living routs of Brassica Kaber (DC.) Wheeler and Brassica nigra. L. (Erassicaeeae) were inhibitory to the germination of spores of the mycorrhizal fungi Glomus intraradices Schenck & Smith and Glowns etunivatum Becker & Gerd. Roots from two similarly non‐mycotrophic species, spinach (Chenopodiaceae) and Amaranthus retroflexus L. (Amaranthaceae). had no effect on the germination of spores of G. intraradices. The roots of two out of three mycotrophic species examined were stimulatory to germination of C intraradices. To test the hypothesis that the inhibition of VAM fungus spore‐ germination by the roots of B. kaber and B. nigra was due to isothiocyanates (mustard oils), lysine arginine and gtutathione Mere added separately to the nutrient solutions applied to the plants. These compounds were expected to react with isothiocyartates released into tlu1 rrtizosphcre. In one experiment, lysine, tirKiniiK‐ arid glutarhione rcsfored the‐ avrminauim of G. intraradices to control levels for B. kaber and nearly to the control levels for B. nigra. In a second experiment employing lower concentrations of lysinc. jtryinitie and glutathimie, irraination of spates of G. efttmeantai in the presence of B. kabcr roots was restored nearly to the levels of controls. In the same experiment, these treatments had no significant effects on spore germination in the presence of B. nigra roots. Lysine and arginine also protected spores of G. etunicatum from in vitro reactions of B, nigra root glucosinolate; extract with myrosinase. The involvement of isothiocyanates in the resistance of mustards to VAM Fungi is discussed.