Food habits of the threatened bat Leptonycteris nivalis (Chiroptera: Phyllostomidae) in a mating roost in Mexico

The objective of this study was to collect and present data on the food plants that a vulnerable migratory nectarivorous bat, Leptonycteris nivalis, used during its seasonal stay at a cave in Tepoztlan, Mexico. This cave is the only mating roost known for this species. Pollen grains from faeces and fur were examined. Little is known about the diet of this bat, especially in the southern half of its distribution. Pollen belonging to 10 plant species was found from five families: Cactaceae (Stenocereus beneckei), Bombacaceae (Ceiba aesculifolia, Pseudobombax ellipticum), Convolvulaceae (Ipomoea arborescens), Fabaceae (Calliandra houstoniana, Bauhinia ungulata), and Amaryllidaceae (Agave dasylirioides, A. horrida, A. inaequidens, A. salmiana). Bats showed the highest dietary diversity in November. There were no significant differences in diet between sexes. Of the four Agave species, two have paniculate inflorescences that are commonly attributed to bat pollination, while the other two had spicate inflorescences, which are considered to be primarily insect‐pollinated.     

Comparative morphology of the otolith of the triplefins (family: Tripterygiidae)

Otolith morphology may provide useful information about the triplefin fish family Tripterygiidae. A comparative study of the otolith of 40 tripterygiid species was conducted to identify the most appropriate taxonomical characters that can separate the species and genera of the family Tripterygiidae. Among other otolith characters, it is possible to distinguish characters that clearly define a taxonomic group (genus or species), and other characters that are shared by several genera, but may be only useful to define certain species within a genus. Ontogenetic changes in the otolith of the triplefin fishes studied are evident. The otolith of the juvenile Ucla xenogrammus was the most similar to the adult otolith, while otolith of the juvenile Blennodon dorsale was the least similar to the adult otolith.     

Maintenance of colour polymorphism in the leaf beetle Chrysophtharta agricola (Chapuis) (Coleoptera: Chrysomelidae: Paropsini)

Intra-specific colour differences in insects may occur as a result of environmental factors such as food type, temperature and humidity, or may be under genetic control. These colour polymorphisms may result in fitness differences through several mechanisms, including mate selection, camouflage from or warning to natural enemies, and heat absorption. Two colour morphs of adult Chrysophtharta agricola (Chapuis) (Coleoptera: Chrysomelidae: Paropsini) are present in the field in mainland Australia and Tasmania: a common green-brown form, and a rare black form. Tasmanian populations were sampled to assess the frequency of each morph at eight localities. The black form represented less than 3% of beetles (N=1724), with the proportion not significantly different between localities. Crossing tests using the two colour morphs of C. agricola showed that the black form was genetically dominant over the common form. To assess whether colour morphs had any fitness differences, we measured pre-oviposition period, fecundity, longevity, adult size and egg hatch rate, which each showed no significant difference between colour morphs. Field sampling of mating pairs and rearing the offspring of field-collected females showed no evidence of non-random mating. Modelling the population over 100 generations confirmed that for this species, melanism is controlled by a dominant but neutral allele, and, thus, is maintained at a constant low level in the population.     

Pollen evidence of historical forest disturbance on the Wasatch Plateau, Utah

Environmental indicators from lake sediments provide excellent opportunities to improve understanding of forest disturbance processes and corresponding changes in forest composition. Our research provides a methodology for assessing recent, historic, and prehistoric disturbances using lacustrine sediment records. We collected sediment cores from Blue Lake, a small subalpine lake on the Wasatch Plateau in central Utah. These cores record environmental changes caused by both spruce beetle ( Dendroctonus rufipennis Kirby) and human (logging and livestock grazing) modification. We observed deteriorated insect remains in the lake sediments. These remains correspond temporally with a historic spruce beetle outbreak, though alkaline conditions in the lake water may have inhibited preservation of bark beetle remains. Pollen data reveal that despite the unprecedented level of mortality among Engelmann spruce ( Picea engelmannii Parry ex Engelm.) resulting from the spruce beetle epidemic, logging activities subsequent to Euro-American settlement appear to be the most severe disturbance to the Blue Lake watershed over the last 750 years.     

Effects of chemicals on the germination of pollen grains of Torenia asiatica Linn

Germination studies of the pollen grains of a Scrophulariaceae plant, Torenia asiatica Linn. have revealed that the maximum percentage of germination and longer tubes were attained in 15 percent sucrose solution. Among the chemicals tried, calcium and boron enhanced germination. Less germination occurred among grains treated with potassium or magnesium salts. Abnormalities such as branched tubes with or without vesicles were found in chemically treated pollen grains.       

Larval food sources of Centris (Heterocentris) analis (Fabricius, 1804) (Hymenoptera: Apidae), an oil-collecting bee

Pollen analysis of larval food allows identification of plants used as nest provision sources. Considering the importance of Centris analis in pollination, we aimed to identify its plant sources, food niche width in Cerrado, and analyze the use of sources between cool/dry and warm/wet seasons. We sampled 22 nests collected in two areas from February 2008 to October 2009. Heteropterys spp. (Malpighiaceae) were the main pollen sources, but Byrsomia spp. (Malpighiaceae), Banisteriopsis malifolia (Malpighiaceae), Solanum lycocarpum (Solanaceae) and Machaerium spp. (Leguminosae) were also important food sources. There was no difference in the use of the sources between the seasons (F_1,100?=?0.001; p?=?0.979). Despite the high number of pollen types (n?=?14) the food niche widths were low, H?=?0.777 and H?=?0.949, which can be explained by the dominance of some food items. Hence, C. analis use, profusely, a few plants as food sources that could be considered conservation targets.     

Carapace ontogeny of the bromeliad dwelling ostracod Elpidium bromeliarum Müller, 1880 (Crustacea: Ostracoda)

Ostracods have discontinuous development, marked by ecdyses, and determinate growth. Ontogenetic studies have suggested a pattern of nine postembryonic stages (eight juvenile phases and the adult) for the main freshwater ostracod superfamilies Cypridoidea, Cytheroidea and Darwinuloidea. However, cases of a supposed extra moult in the adult stage have been proposed for some ostracod species, which would amount to 10 postembryonic growth stages. One such example is Elpidium bromeliarum Müller, 1880, a cytheroidean that inhabits tank-bromeliads. The present study is aimed at investigating the ontogenetic development of E. bromeliarum using width and length measurements, as well as carapace and appendage morphology in order to test the existing hypothesis of an additional growth stage in adults of this species. Our results revealed nine postembryonic growth stages (eight juvenile and the adult), with sexual dimorphism beginning its expression in the last juvenile stage. Thus, the ontogenetic development of E. bromeliarum agrees with the overall pattern observed for podocopid ostracods and the hypothesis of 10 postembryonic growth stages was not corroborated. We argue that the inability to differentiate juveniles from adults, or different species from one another, may have misled to the assumption of an additional moult in E. bromeliarum.     

Effective strategy of the overwintering of semiaquatic bugs: overwintering of Velia caprai (Heteroptera: Gerromorpha: Veliidae)

Overwintering of Velia caprai was studied during the winter months 2006–2007 in the area of South Bohemia (Czech Republic) by (1) field phenological observations and samples, (2) study of artificially established experimental cohorts in an unheated glasshouse, and (3) auxiliary experiments in a laboratory. Velia caprai has a unique way of overwintering within the gerromorphan bugs that is rare among insects generally; it can overwinter in both an adult and an egg stage. Most females reach sexual maturity before overwintering, mate with mature males, overwinter actively on the water surface and lay eggs during the winter. The dormant eggs can be induced to hatch by increasing temperatures. Winter oviposition can be interpreted as a sign of a risk‐spreading reproductive strategy. The overwintering of both adults and eggs provides a chance to adapt to changes in the local environmental conditions and could be an important determinant in broad variability of life‐history traits.     

Survival and reproduction of the mussel Xenostrobus securis (Lam.) (Mollusca: Bivalvia: Mytilidae) in a Western Australian estuary

Summary

The Swan estuary is subject to extreme temporal and spatial variations in salinity. Downstream populations of the mussel Xenostrobus securis (Lamarck, 1819) are exposed to a seasonal range from 1·5‰. Cl to 20·0‰. Cl. In summer the estuary is progressively filled with saline water from the sea; in winter it is flooded by fresh river run-off water from the heavy and concentrated winter rains. The autumn fall in salinity is usually very rapid and constitutes a severe physiological shock for organisms inhabiting the estuary.

The physiography and hydrology of the Swan estuary are described. Experiments are reported on the salinity tolerance and behavioural responses to salinity stresses of adult mussels and larval stages.

Adult mussels show no ability to osmoregulate (except possibly at very low salinities). They can tolerate environmental chlorinities at least as high as 31‰. Cl and can withstand sudden dilutions from at least 18‰. down to 1‰.. They are capable of survival at 1‰. for many months.

Closure of the shell valves in response to sudden dilutions of the medium is a behavioural mechanism minimizing physiological shock. Adult mussels remain inactive with the valves closed indefinitely at chlorinities below 2‰.. However, the internal body fluids of the mussels become isotonic with the medium after a few days. Adult salinity tolerance and behavioural responses are sufficient to meet the conditions occurring in the estuary, and adult salinity tolerance is unlikely to limit distribution of the species.

In laboratory dishes eggs may be successfully fertilized, and normal cleavage occurs in water between about 8 to 9‰. and 17·5‰. Cl. This tolerance range of developing larvae imposes upstream limits on the distribution of the mussel and precludes any possibility of larval dispersal between adjacent estuaries by way of the sea.     

Age-related body weight,fecundity and population change in a south Dorset sika population (Cervus nippon); 1985–1993

Density-related changes in performance have been documented for a number of different ungulate species, with recorded decline in body weight, fecundity and both juvenile and adult survival as population densities increase. While density-dependent responses of this kind have been explored in some detail in red, roe and fallow deer, little published information is available on demographic responses to density in European populations of sika deer (Cervus nippon). This paper offers an analysis of the dynamics of two populations of sika from the south of England from 1985–1993. Data on age-related body weights for males and females and pregnancy rates of females are taken from analysis of cull records of 321 males and 534 females culled during that 8-year period. We describe trends in body mass of adult and juvenile sika of both sexes, and consider changes in pregnancy rates of both mature and yearling females in relation to changes in relative abundance. Despite steadily increasing population density between 1985 and 1991/1992, no consistent decline was recorded in body weight or condition (as measured by % cover of kidney fat) for calves or yearlings of either sex, or for mature females. A decline in recorded body weight of adult males was not significantly correlated to ranked relative abundance. Fecundity was high (with > 90% of mature females sampled found pregnant). Most mature females found pregnant were also lactating. The proportion of animals that conceived as yearlings (72%) was lower than that recorded for more mature hinds; however there is some indication that the difference recorded may simply reflect the fact that yearlings may conceive later in the season than older animals. No significant differences were apparent in the proportion of either adult or yearling females found pregnant in different years.     

A putative hybrid swarm within O?nopsis foliosa (Asteraceae: Astereae)

O?nopsis foliosa var. foliosa and var. monocephala are endemic to short-grass steppe of southeastern Colorado and until recently were considered geographically disjunct. The only known qualitative feature separating these 2 varieties is floral head type; var. foliosa has radiate heads, whereas var. monocephala heads are discoid. Sympatry between these varieties is restricted to a small area in which a range of parental types and intermediate head morphologies is observed. We used distribution mapping, morphometric analyses, chromosome cytology, and pollen stainability to characterize the sympatric zone. Morphometrics confirms that the only discrete difference between var. foliosa and var. monocephala is radiate versus discoid heads, respectively. The outer florets of putative hybrid individuals ranged from conspicuously elongated yet radially symmetric disc-floret corollas, to elongated radially asymmetric bilabiate- or deeply cleft corollas, to stunted ray florets with appendages remnant of corolla lobes. Chromosome cytology of pollen mother cells from both putative parental varieties and a series of intermediate morphological types collected at the sympatric zone reveal evidence of translocation heterozygosity. Pollen stainability shows no significant differences in viability between the parental varieties and putative hybrids. The restricted distribution of putative hybrids to a narrow zone of sympatry between the parental types and the presence of meiotic chromosome-pairing anomalies in these intermediate plants are consistent with a hybrid origin. The high stainability of putative-hybrid pollen adds to a growing body of evidence that hybrids are not universally unfit.     

Qualitative relations of egg size,egg production and colony size in some ponerine ants (Hymenoptera: Formicidae)

The sizes of eggs and reproductives of 13 species of ponerine ant were measured, and information about the mature colony sizes, ovarial anatomy and individual fecundities of a selection of ponerine species was assembled. Inter-specific variation in the size of colonies was found to be poorly related to aspects of individual fecundity, and although the few cases of polygyny were associated with larger colony sizes, monogynous species often attained even larger sizes. Within the subfamily individual fecundity may be increased primarily by a decrease in the maternal investment in individual eggs, and perhaps to a lesser extent by an increase in the number of ovarioles in each ovary or an increase in the length of each ovariole. The diet of a species and the longevity of adult worker ants relative to the duration of their larval development are suggested as factors besides reproductive characteristics that might also contribute to differences in colony size.     

Butterflies (Lepidoptera: Papilionoidea) of Mount Kilimanjaro: family Pieridae,subfamily Coliadinae

This paper forms part of a series on the butterfly fauna of Mount Kilimanjaro. Three genera (Catopsilia, Colias and Eurema) with eight species of Coliadinae are believed to occur within the main forest zone. However, of these, one or two may prove to be no more than variants of a third species, Eurema desjardinsii. A fourth conventionally recognized member of the complex may occur on the lower slopes below 1800 m. The widespread species Eurema hecabe occurs on the lower slopes, but records are sparse, and no records of its close relative Eurema floricola, with which it has often been confused, have been found. The need for original field and laboratory research on the taxonomy of African Eurema species is stressed. Keys to adult Coliadinae found in Tanzania, with colour illustrations, are included as online supplementary material.     

Long copulations and post-copulatory ‘escort’ behaviour in the locust leaf miner,Odontota dorsalis (Coleoptera: Chrysomelidae)

The adult behaviour of Odontota dorsalis on its host plant Robinia pseudo-acacia was studied by following marked individuals in nature. Copulations often lasted several hours, and were characteristically followed by long escort phases in which males remain mounted atop females. Pairing lasted as long as several days. Most pairs broke up around the time of day when most females were ovipositing. Females normally laid a small cluster of eggs once per day. Both sexes mated repeatedly, and females did not resist copulations.

Long pairings in O. dorsalis may have evolved because the encounter rate between the sexes is high and costs to the female low. It is suggested that escort behaviour will be found in many other species with similar ecology and in which males remain mounted on females while copulating.     

Gray Partridge foraging ecology in eastern South Dakota

We examined crop contents of 217 Gray Partridge ( Perdix perdix ) collected during a two-year period in eastern South Dakota. Row crop grains (corn, sunflowers) dominated late fall, winter, and spring diets. Small grains (oats, barley, wheat, rye) were rarely consumed although fields of small grains were widely available. During a severe winter when waste row crop grains were buried by snow, partridge consumed more leafy vegetation. Insects dominated the early summer diet, while foxtail ( Setaria spp.) seeds were a major late summer and early fall food.     

Development rates,larval survivorship and wing length of Culex pipiens (Diptera: Culicidae) at constant temperatures

In this study, the effects of rearing temperature on survival and development rate of pre-imaginal stages and on wing length of adult Culex pipiens (Diptera: Culicidae) were evaluated. Larvae I were reared until adult emergence at seven constant temperatures between 7 and 33°C. The highest survival was found at 25°C. The development rate of the immature stages decreased with increasing temperature until 30°C. The threshold temperature and thermal constant were, respectively, 5.2°C and 186.5 degree-days for males, and 5.5°C and 199.5 degree-days for females. According to a non-linear model, the lower and upper thermal thresholds were, respectively, 8.4°C and 34.4°C for males, and 9.8°C and 34.2°C for females. Wing length decreased with increasing temperature. Wings of females were longer than those of males. This study showed that survival and development of immatures and adult size were affected by rearing temperature. In addition, results suggest that this effect may differ between sexes.     

Life strategies in the evolution of the Colorado squaqfish ( Ptychocheilus lucius )

The Colorado squawfish, a large predaceous cyprinid, is a generalist species adapted to the large seasonal water fluctuations, low food base, and changing riverine subsystems of the Colorado River. Extant at least as early as the Miocene epoch, Ptychocheilus has survived by incorporating life strategies to deal with changing climates varying from arid to pluvial. Migration and long-term movement patterns appear to have evolved as tactics to perpetuate a grand reproductive strategy for exploiting the changing habitats and general environmental conditions of the late Cenozoic era. Accordingly, high mobility of a large fish would aid in selection of optimum spawning, nursery, and adult habitats in the dynamic lacustrine/riverine system that existed at that time. A spatial separation of life stages thus produced would aid in the reduction of intraspecific competition. Large size, long life, and late spawning of Ptychocheilus indicate that mortality of young must be disproportionately high compared to that of the adult form. Growth to a large size should reduce predation by other fishes and, once attained, would facilitate long distance movement for reproduction, feeding, and other purposes. Such a strategy, formerly highly adaptive, may now be implicated in the decline of this species in controlled riverine systems.     

LVII.—Pityosporites Westphalensis,sp. nov., an abietineous type pollen grain from the coal measures of Britain

Abstract

Recent investigations of the microfloras of the Upper Carboniferous coal-seams of a part of the South Wales Coalfield have demonstrated the presence in these coals of pollen grains of typical Abietineous aspect referable to the genus Pityosporites Seward. A new species—P. westphalensis—is described. The grains are found distributed through the seam as part of the overall microflora and are not associated with any male fructifications or sporangia. However, on morphological grounds they are referable to the Coniferae and indicate the existence during late Carboniferous (Coal Measures) times of a group of conifers which quite probably were the early representatives of the Abietineae. The geographical and vertical distributions of Pityosporites in the British Coal Measures are given as far as they are known at present, and it is concluded that this hitherto unknown group of Coal Measures conifers made a small but nevertheless significant contribution to the floras of those times.     

Range and natural history of point-tailed palmcreepers (Aves: Furnariidae)

The point-tailed palmcreeper Berlepschia rikeri is a distinctive Furnariidae species, very shy and poorly known. In this paper we present natural history notes on this species as well as a detailed review of its range. This paper summarizes anecdotal observations gathered during 10 years of ornithological investigation of the central Brazilian Cerrado, as well as data obtained in 13 Brazilian and overseas collections and from online databases. We found that B. rikeri is widely distributed across north and central South America, where it is strictly associated with palm groves, especially those of Mauritia spp. and Orbignya phalerata. Despite being a habitat specialist, this species can be found in a wide spectrum of vegetation formations, from lowland rainforests to high plateau grasslands. This is an insectivorous species, which constructs a stick nest concealed within the fronds of Mauritia palms. Its juvenile plumage is similar to that of the adult.