Showing papers in "American Midland Naturalist in 1967"

Experimental and Natural Hybrids in North American Typha (Typhaceae)

Abstract: Typha latifolia L., T. angustifolia L. and T. domingensis Pers. occupy distinct but overlapping ecological and geographic ranges. The plants are protogynous, self-compatible and rhizomatous. Leaf mucilage glands and gynophore hair apices provide useful new taxonomic characters. The three interspecific hybrids synthesized in the field in California are intermediate between their parents and similar to numer- ous putative hybrids. Typha angustifolia X latifolia (T. X glauca Godron), widespread in temperate zones, and T. domingensis X latifolia, known from California and southern Europe, are morphologically similar and mostly sterile. Typha angustifolia X domingensis, known as hybrid swarms in California and reportedly southern France, is mostly fertile. Trihybrid populations occur in California and probably in the Southeast. The three species and three hybrids are diploids (n = 15). Microsporogenesis is regular in the three species and in T. angustifolia X domingensis with 15 bivalents at MI. About 1 to 6 univalents per PMC, infrequent bridges and rare micronuclei occur in both T. angustifolia X latifolia and T. domingensis X latifolia. The species remain distinct due to either hybrid sterility or relatively narrow zones of sympatry. Hybridization and introgression have probably allowed the evolution of ecotypic races. The hybrids appear to be better adapted than the parents to habitats with rapidly fluctuating water level.

Stream Order and Species Diversity of Fishes in an Intermittent Oklahoma Stream

Abstract: The relation between stream order and species diversity of fishes in the Otter Creek drainage basin, a 6th-order intermittent system in north-central Oklahoma, was determined. Fishes were collected after eight months of continuous stream flow and again after a severe drought and two or three days of stream flow. Twenty species of fishes were collected. Species diversity values for both collections were remarkably similar. Species diversity increased progressively with stream order and the correlation coefficient between stream order and species diversity was 0.96. Effects of drought and influx of oil field brines are discussed.

Population Dynamics and Productivity of the Crayfish, Orconectes virilis, in a Marl Lake

Abstract: The population dynamics of the crayfish, Orconectes virilis, were studied to define the role of the crayfish as a consumer in a marl lake ecosystem. Insight was gained into the factors controlling its production. There was year-class fluctuation in the age structure of the crayfish population. Males had a greater growth rate than females. After age-I, mortality rates for females were greater than for males. Both sexes matured after a molt in July, at age-I; mating followed and eggs were laid the following spring. Reproductive capacity was 58% of the potential capacity. Two-year-old females produced most of the eggs (92.5%). The estimated reproductive rate for 1963 was low (0.78 per generation) due to poor survival of the 1963 year class. The maximum life span for both sexes was three years. Newly hatched young left the females and remained in shallow water. Adult females then molted and migrated to a depth of 7.6 m, where most of them remained all summer. A migration of males to deep water followed. 0. virilis acts as a herbivore in marl lakes, feeding chiefly on the algae and the "aufwuchs" with marl incrustations, though it is also a scavenger on animal materials. The peak standing crop of crayfish (119.5 kg/ha) occurred in the spring of 1963. The annual net production of crayfish was 205.3 kg/ha, about 8.9 times greater than an estimate of the productio-n of all other bottom invertebrates in West Lost Lake (23.0 kg/ha). The total net production of 310.8 kg was 2.33 times the average standing crop during the summer of 1963. This crayfish has a lower daily numerical turnover rate (2.0%) than the amphipod Hyalella (2.9%) and the cladoceran Daphnia (25.0%). Population size is probably regulated by cannibalism and natural mortality at molting.

Temperature Responses of the Periodical "17-year" Cicada, Magicicada cassini (Homoptera, Cicadidae)

Abstract: Periodical cicadas are basking animals and reach body temperatures exceeding air temperature. They possess behavioral regulatory mechanisms to prevent the body temperature from exceeding about 32 C. They are unable to fly below 20 C. Some activities of cicadas are temperature dependent, notably flight of males, singing and synchronized chorusing. Other activities are relatively more independent, especially flight of females, copulation and oviposition.

A Comparison of the Life Histories of Coastal and Montane Populations of Ambystoma macrodactylum in California

Abstract: The disjunct, coastal endemic Ambystoma macrodactylum croceum was compared with two populations of A. m. sigillatum (1980 and 2450 m) from the Sierra Nevada of California. A. m. croceum and A. m. sigillatum 1980 m breed in temporary ponds, but A. m. sigillatum at 2450 m requires permanent ponds. The last has a 14-month larval period with a 2-3 month overlap of larval age classes, whereas the others have a short (3-4 month) larval period. A. m. croceum breeds in January and February, A. m. sigillatum from late May (1980 m) through June (2450 m). In all areas climatic conditions control the primary activities. Rainfall is the only important governing factor for A. m. croceum. It controls the breeding migration, dispersal of juveniles, time of breeding, and (because it determines the length of time the ponds persist) determines size attained at metamorphosis. For A. m. sigillatum the most important factor is temperature, determining the time of breeding (thaw) and the larval and adult growth rates. A. m. croceum deposits eggs singly on vegetation near the surface in shallow water. In A. m. sigillatum, eggs are clustered under logs and bark near the bottom in the deeper portions of the ponds. Size at metamorphosis is approximately the same in A. m. croceum (37.5 mm S-V) and A. m. sigillatum from 2450 m (37.8) but the former attains this size in 90-140 days whereas the latter requires 14 months. The A. m. sigillatum from 1980 m metamorphose after 80-90 days, at 25.0 mm S-V, approximately the size reached by the 2450 m population after the first growing season. Metamorphosis seems to be triggered by intrinsic factors in A. m. sigillatum at 2450 m but by extrinsic factors (drying of the ponds) in the others. The larvae of A. m. croceum are secretive at all stages but their behavior varies and has been generally correlated with stage of development. Larval A. m. sigillatum (2450 m) are secretive in hatchling and metamorphic stages but active in open, illuminated portions of the ponds otherwise. The breeding migration of A. m. croceum is stimulated by heavy rainfall and takes place only on rainy nights. The migration of A. mi. sigillatum was not observed but occurs while snow and some ice are present. Sexual maturity is reached during the second year of life in A. m. croceum, during the third year in A. m. sigillatum from 2450 m. Both A. m. croceum and the Sierran A. m. sigillatum are derived from ancestral populations to the north. The isolated A. m. croceum shows the greatest divergence in life history compared to present-day northern populations.

Social Behavior of a South American Leaf Fish, Polycentrus schomburgkii, with an Account of Recurring Pseudofemale Behavior

Abstract: This account of social behavior is restricted to hostile, sexual, and parental behavior. The major color patterns can be characterized as banded juvenile, nonbreeding brown adult, territorial black g', spawning pale 9, and parental black g. A glossary is given of the motor patterns characterizing hostile behavior. An abstracted typical sequence of motor patterns is described as are details of orientation and of appeasement behavior. Mature g'' hold territories which may be unusually small in aquaria. The most striking feature of the aggressive behavior is the near absence of damaging attacks. Much of the sexual behavior of the g involves motor patterns seen in hostile behavior. The g responds aggressively to the approach of the 9 . After entering his lair she capsizes and places her vent at the ceiling where the eggs are deposited. The g remains below the 9 in a normal upright position, washing the sperm up to the eggs. Commonly during such a spawning, subordinate g' g in the aquarium approach while the manifesting color patterns typical of the spawning 9 9 . If the dominant g attacks, these pseudo9 9 may skim although in an upright position. Evidently the pseudo9 is attempting to steal a fertilization. The parental g' fans the eggs or larvae, but sporadically. He removes intruders such as snails, but he does not retrieve the progeny. Remarkably the adults, breeding or nonbreeding, were never seen to eat any of their own young; this is doubtless an adaptation necessary to the perpetuation of such an effective piscivore.

Sympatry Changes and Hybridization Incidence in Mallards and Black Ducks

Abstract: ASTRACT: Changes in general fall and winter distributions of Mallards and Black Ducks over the past century have resulted in markedly increased sympatric contact during pair formation between these two forms, and have been responsible for increased opportunities for hybridization. Bureau of Sport Fisheries and Wildlife records of hybrids from 34 states indicate a minimal current hybridization rate that is about 4% of the frequency expected on the basis of mating according to mathematical probabilities of chance contact. Thus, hybridization is most frequent where both forms are almost equally abundant, indicating that no reinforcement of differences reducing hybridization in the primary zone of contact is detectable. The primary zone of sympatry has moved eastward approximately 300 miles during the past half century and will almost certainly continue to do so. Owing to its much smaller gene pool, the Black Duck is vulnerable to eventual swamping through hybridization and introgression, although the present hybridization rate is sufficiently low as to make this unlikely in the foreseeable future.

Vegetation-Soil Relationships on Saline Soils in Northern Kansas

Abstract: The vegetation of northern Kansas salt marshes was ana- lyzed and vegetation-soil relationships studied. It was determined that Suaeda depressa (Pursh) S. Wats. and Disti'chlis stricta (Torr.) Rydb. were the most salt-tolerant species. Others that were able to withstand the higher salinity were Tamarix pentandra Pall. and Sporobolus texanus Vasey. The most extensive marsh communities were the highly saline Suaeda depressa and the Distichlis stricta-Suaeda depressa, whereas in areas of lower salinity a Hordeum jubatum-Distichlis stricta complex of communities was prevalent. Distributional relations of species indicate that the most important single factor distinguishing halophytes was their ability to withstand high salinities and not their need for a highly saline environment. It was found that the most salt-tolerant species made more robust and denser growth in low- to nonsaline areas than in the most highly saline environments in which they were the pioneer species. Schaffner (1898) studied the phytosociology of marsh plants in northern Kansas and described the zonation of vegetation by use of qualitative techniques. In this study, he divided the vegetation into four main types: vegetation of streams including Scirpus americanus Pers., S. paludosus Nels., and S. acutus Muhl.; vegetation of barrens including Polygonum ramosissimum Michx., Suaeda depressa (Pursh) S. Wats., Distichlis stricta (Torr.) Rydb.; successful invaders of saline soil including Iva annua L., Sporobolus texanus Vasey, Atriplex patula var. hastata (L.) Gray (his A. expansa) , Aster ericoides L., Hordeum jubatum L., and Ambrosia psilostachya D. C. var. coronopifolia (T. & G.) Farw.; and finally the unsuccessful invaders, which include the prairie species that are not able to succeed in highly saline soils. In the present study the saline areas of Cloud and Republic counties were visited and an attempt was made to find correlations between plant zonation and soil characteristics. Quantitative vegetational and soil analyses on plant communities corresponding to Schaffner's (1898) are reported on in this research. Besides this early work very little ecological research has been done in this area, but floristic surveys of Republic Co., Kansas, by Morley (1964) and Fraser's (1931) flora of Cloud Co. do list the species of these marshes. Unfortunately, the Big Marsh which Schaffner (1898) studied has been danmmed up and is now a lake with only a few saline spots around it, whereas the Tuthills Marsh is heavily grazed at present, but still has highly saline areas which maintain the char-

Notes on Clavarioid Fungi. VII. Redefinition of the Clavaria vernalis - C. mucida Complex

Abstract: Thirteen species of clavarioid lichenoid fungi are grouped into a new genus, Multiclavula, emphasizing hyphal morphology as a unifying characteristic. Included are M. sharpii n. sp., one species formerly placed in Clavaria, seven from Clavulinopsis and four from Lentaria. Of these species, only M. constans is free-living: the others are associated with algae, mosses, or allegedly associated with a slime mold. The type species of the genus is designated as M. corynoides (Pk.) Pet. (Clavaria corynoides Peck). Keys, descriptions and illustrations of basidial and spore details are given.

Population Structure and Biomass Production by a Stream Salamander

Abstract: A life-table based on collections from a population of Desmognathus fuscus in Gaston Co., North Carolina, is presented. An estimate based on the weight of captured individuals predicts that salamanders from each clutch will provide 17.5 g of salamander biomass to other community predators and decomposers, or an average of 1.8 g per year. Population density is estimated to be between 0.4 and 1.4 salamanders per square meter of stream bed. The corresponding average annual production would then fall between 0.1 and 0.3 g/m2 of stream bed. INTRODUCTION Measures of the importance of populations of a particular species in a particular community are usually based on abundance and size of the individuals of the species. When these measures are used to define the importance of plant species, the information gained is of considerable value, for the physical structure of the community can be derived from them. The same inforrmation about an animal species, however, does not define a particular structure. A more interesting measure of the importance of an animal species in its community would be an estimate of the annual production of the pop'ulation of that species. The resulting figure can then be compared with the production of the community as a whole or with that of populations of other species. This paper will present an estimate of the biomass production rate of the stream salamander, Desmognathus fuscus. A population of D. fuscus in Gaston Co., North Carolina, was sampled in five spring collections during 1961 and 1962. The data obtained from these collections are presented graphically in Fig. 1. POPULATION STRUCTURE The initial step in the technique of production estimation which will be utilized in this paper is the derivation of a life-table for the population. The life-table gives the rate at which animals in different age classes are dying, or contributing their biomass to the community. When these rates are multiplied by the weights of the animals in these age groups, the desired rates of biomass production are obtained. The life-table derived from the data in Fig. 1 is given in Table 1. The construction of this table follows the directions of Birch (1948), and the example of Organ (1961) for salamanders of the genus Desmognathus. The remainder of this section is a description of the construction of the life-table. 1 Present address: Department of Zoology, University of Washington, Seattle, Washington 98105.

Effects of Dimethoate on Small Mammal Populations

Abstract: The effects of an insecticide, dimethoate, on small mammal populations comprising three species, the prairie vole (Microtus ochrogaster), the house mouse (Mus musculus), and the prairie deer mouse (Peromyscus maniculatus), were investigated by means of live trapping grids in an Indiana clover field. House mice decreased in num- bers after spraying while prairie voles increased and deer mice remained at the same density level. Density of insects declined greatly after spray- ing, but no evidence was found to indicate that the insecticide caused direct mortality in any of the mammal species or had any additional effect on the habitat. It is postulated that the abrupt decline in insects was related to a drift in the mammal population composition from an omnivore to a herbivore species. The present paper reports on an intensive study of small mammal populations in a clover field before and after experimental spraying with dimethoate, an organic phosphate insecticide, at levels that might be used in routine agriculture. Changes in insect populations, in weather, in vegetation, and in the amount of residue present were followed in an attempt to evaluate the possible indirect effect of the insecticide on the clover field ecosystem. Only by considering the ecosystem as a whole can possible indirect effects of sublethal

Small-Mammal Distributions Across the Prairie-Forest Transition of Minnesota and North Dakota

Abstract: Thirteen taxa of small mammals were collected in the continuous forest, aspen groves, riparian woodland and prairie areas of the prairie-forest transition. Mammals captured were placed in three groups on the basis of habitat selection. Of the forest species, Peromyscus maniculatus gracilis was the most restricted and occurred only in or near conifer forest. P. leucopus noveboracensis was found in coniferous, deciduous and river-bottom forests and in large aspen groves. Clethrionomys gap peri had a similar distribution, but was also found in some small aspen groves with grassy ground cover. Tamias striatus was collected in the continuous forest and nearby large groves. Eutamias minimus and Synaptomys cooperi were collected only in the continuous forest. The prairie species, P. m. bairdii, Onychomys leucogaster and Microtus pennsylvanicus, were found essentially in grassland situations. P. m. bairdii also occurs in aspen groves and river-bottom forests where P. 1. noveboracensis is absent. M. pennsylvanicus appears to be a permanent resident in young groves with a grassy undercover. The nonselective species, Sorex cinereus, Blarina brevicauda and Zapus hudsonius, were found throughout the area in all habitats trapped. Sorex arcticus may also be present in moister habitats throughout the transition. The small-mammal fauna of the prairie-forest ecotone includes fragments of both prairie and forest faunas and reflects the state of flux in the plant associations.

Presettlement Forest Composition of the River Hills Region of Missouri

Abstract: Missouri foresters have reported the development of a dense sugar maple (Acer saccharum) understory in the white oak (Quercus alba) stands of the, loess hills of the Missouri River in east- central Missouri. To determine the actual extent of this apparent inva- sion of sugar maple, Government Land Office survey records were used to determine the presettlement forest composition of the River Hills. White oak was the most important species in presettlement forests throughout the River Hills. Sugar maple was also relatively important but was unevenly distributed. This uneve.n distribution, no longer exist- ing in present forests, was probably the result of fires which burned into the River Hills from adjacent prairies. In areas where the Missouri River flows north to south the River Hills to the east of the river were protected from fire, and the fire-sensitive sugar maple was able to survive.

Cattail Moisture Requirements and their Significance to Marsh Management

Abstract: A hybrid cattail resulting from a natural cross of Typha latifolia and Typha angustifolia was studied under greenhouse and field conditions in an attempt to determine optimum soil moisture and water depth for germination. growth and vegetative reproduction. Seeds in greenhouse tests required flooding for germination, but no differences in percent germination were detected between water depths of 1 inch and 6 inches. Germination was reduced 50% by storage of seed for 1 year at room temperature and humidity. No germination of artificially established seeds occurred in the field. The fastest rate and amount of growth was recorded for plants in 1 inch of water. Plants in saturated soil and 6 inches of water grew nearly as well as plants in 1 inch of water. Vegetative reproduction was similar in saturated soil and in soil flooded with depths of 1 inch of water and 6 inches of water. Management recommendations are discussed.

Life History and Ecology of Epeorus pleuralis (Banks) (Epemeroptera: Heptageniidae)

Abstract: The life history and ecology of Epeorus pleuralis in Morgan's Creek, Kentucky, were studied over a 20-month period beginning February, 1963, and continuing through September, 1964. E. pleuralis has a univoltine life cycle. Hatching begins in late September or early October and extends through May, with a peak in January or February. Emergence starts in late February or early March and continues into June, with a peak in late April or early May. Growth proceeds during the winter despite very low temperatures. The nymphs are herbivorous and eat principally allochthonous leaf detritus, with some diatoms. The nymphs were most abundant in a cascade near the spring source of the stream. Their longitudinal distribution in the stream was largely determined by the interplay of temperature, substrate, and current. They were restricted to cool-water areas and to fast-water habitats, such as riffles and cascades. They were found mainly on loose, rubble substrate. The seasonal abundance of the nymphs was controlled mainly by factors associated with life-history phenomena. Temperature had some effect on these phenomena but was not the only factor involved, especially in the headwaters, where temperatures were nearly constant.

Social Organization in the Mating Calls of Some Neotropical Anurans

Abstract: Observations on the calling behavior of certain neo- tropical frogs indicate the existence of different patterns of social organi- zation. Individuals of some species that do not aggregate for breeding purposes call in duets or trios, whereas individuals of some species that congregate at breeding sites call in duets, trios, or quartets. In at least one species, Hyla elaeochroa, the organization of calling exists only in the initial phase of each chorus. Evidence suggests the presence of dom- inant individuals in the social organization of some species.

Ecology and External Morphology of Lernaea cyprinacea1

Abstract: The external morphology of Lernaea cyprinacea L. in Vigo Co., Indiana, was more variable than has been previously reported. The pregenital prominence was absent in small lernaeids, then de- veloped as a single protuberance, which doubled as the female copepod lengthened and matured. No correlation was found between the location on the host fish and the direction of torsion. Sixteen species of fishes, taken in Vigo Co., were parasitized by L. cyprinacea. They were: Notropis blennius,* N. atherinoides,* N. spilopterus,* N. volucellus,* Semotilus atromaculatus,* Phenacobius mirabilis,* Hybognathus nu- chalis,* Ictiobus niger,* I. cyprinellus,* Lepomis macrochirus, Microp- terus salmoides, Pomoxis annularis,* Catostomus commersoni, Esox americanus,* Moxostoma erythrurum,* and Percina maculata* (asterisk denotes new host records). L. cyprinacea parasitized 0.8% of the fishes examined. Usually there was one parasite per fish, attached near a fin.

Food Habits of the Northern Pocket Gopher on Shortgrass Prairie

Abstract: The food habits of Thomomys talpoides were studied in shortgrass prairie in north central Colorado. The following six plants comprised 88% of the yearly diet: Opuntia polyacantha (49.9% ), Stipa comata (12.1%), Sphaeralcea coccinea (10.3%), Agropyron smithii (10.1%) Bouteloua gracilis (3%), Atriplex canescens (2.5%). The yearly diet consisted of approximately 67% forbs, 30% grasses, and 3% shrubs; approximately 70% of the material eaten was aboveground parts of plants (stems and leaves). Opuntia was by far the most impor- tant food. It was eaten in all seasons, but was utilized most heavily in midwinter, when it comprised 79% of the diet and probably served most importantly as a source of water. In laboratory experiments T. talpoides thrived, using Opuntia as the only source of water. Certain ecological relationships resulting from the dependence on Opuntia by pocket gophers are discussed.

Movements and Seasonal Activity Cycles of the Lizard Uta stansburiana steinegeri

Abstract: A pitfall trapping study in the Mojave Desert has shown that adult female Uta stansburiana stejnegeri Schmidt are more re- stricted to one part of their home range than are males, both during the reproductive season and the rest of the year. A limited number of dis- placements of adult lizards of both sexes have indicated that homing occurs consistently for displacements of less than 250 ft, occasionally for displacements of up to 400 ft and never for those over 400 ft. The homing data indicate that homing takes place only from regions already familiar to the lizard, and that the lizards, therefore, know a much larger area than trapping data indicate. These results are discussed in view of other field studies of Uta stansburiana stejnegeri and of home-range con- siderations in general. Seventeen juvenile movements which were much longer than any adult movements were recorded and these are inter- preted as a dispersal mechanism for the species. Eggs hatch during July- September and hatchlings usually mature the same year. During the time of the peak occurrence of juveniles (August-September) very few adults are captured. Males become active earlier in the year than females.

Transpiration Resistance of Plants

Abstract: An energy budget method is described for using potom- eters to measure the minimum diffusion resistance to transpiration of excised leaves. The method is used to infer the transpiration rate of intact leaves in situ. Values of minimum resistance are given for several coniferous and deciduous trees and shrubs from wet to dry habitats. energy between the leaf and the environment by radiation, convection, and transpiration. The loss of water vapor by a leaf cools a leaf and often keeps the temperature from rising too high for plant proteins when the incident energy is large. During transpiration, water vapor diffuses from the mesophyll cell walls lining the substomatal cavity, through the stomatal channel, to the free air beyond the leaf. In still air there is a boundary layer of moist air adjacent to the leaf surface. The transpiration rate is proportional to the vapor pressure gradient between the mesophyll cell walls and the free air beyond the leaf, and is inversely proportional to the resistance to flow offered by the stomatal channel and boundary layer. It is the purpose of this paper to describe a method of measurement of the diffusion resistance of intact leaves or branches of plants. During the daytime, plants receive direct solar radiation and in- direct solar radiation scattered by the sky and clouds and reflected from the ground and nearby objects. They also receive thermal radia- tion emitted by the atmosphere, the ground and nearby objects. A certain fraction of the incident radiation is absorbed. Leaf tempera- ture adjusts to the energy exchange until the absorbed radiation absR, is balanced by the loss by reradiation, R, the loss or gain by convec- tion, C, and the loss by transpiration, E. The energy budget of a plant is discussed in detail by Gates (1962) and is written as follows:

Ecological Relationships of Two Species of the Lizard Genus Cnemidophorus in the Santa Rita Mountains of Arizona

Abstract: Ecological relationships of locally sympatric populations of the southern whiptail (Cnemidophorus tigris gracilis Baird and Girard), and the Chihuahua whiptail (Cnemidophorus exsanguis Lowe) on the Santa Rita Experimental Range, Arizona, were studied intermittently in 1962 and for their entire period of activity in 1963. Although analysis of stomach contents (consisting largely of termites) and daily activity pattern reveal little divergence between the two species, differences in foraging behavior may reflect differences in the kinds of food resources being exploited. Cnemidophorus exsanguis is an all-female species and has a clutch size half again as great as that of C. tigris. The indications are that competition does occur. About 20%o of the species belonging to the lizard genus Cnemidophorus (whiptail lizards) are uniparental, males being either unknown or extremely rare (Maslin, 1962, 1966). Three of the five species groups recognized within the genus include uniparental species, there being one such species for both the TESSELATUS and DEPPEI groups, and several in the SEXLINEATUS group. With the exception of Cnemidophorus cozumelus, which occurs on the Yucatan Peninsula of Mexico (and nearby islands), all of the uniparental species are restricted to an area from western Colorado and southeastern Utah to north-central Mexico, and from central Arizona to, western Texas. Few previous studies have been concerned with the ecology of the uniparental whiptails, possibly because of the uncertainty evident in the literature as to how uniparental species should be treated taxonomically (see, e.g., Maslin, 1966). Only M'ilstead (1953) has reported a comprehensive ecological study involving both unisexual and bisexual species of Cnemidophorus exsanguis. My paper reports such a study carried out with Cnemidophorus exsanguis Lowe (uniparental) and C. tigris gracilis Baird and Girard (bisexual). DISTRIBUTION AND HABITAT The overall geographic ranges of Cnemidophorus tigris gracilis and C. exsanguis overlap widely. Cnernidophorus tigris gracilis occurs in northeastern Sonora and northwestem Chihuahua, Mexico, in southwestern New Mexico (excluding the extreme southwestern corner of the state) and south-central and southeastern Arizona (excluding the extreme southeastern comer). Cnemidophorus exsanguis occupies about the same geographic range, but occurs more extensively in New Mexico than C. tigris gracilis (Stebbins, 1966). The study reported herein was carried out in the Santa Rita Mountains of southern Ari1 Present address: Museum of Natural History, University of Kansas, Lawrence 66044.

The Effect of Livetrapping on the Movements of Peromyscus

Abstract: The movements of P. leucopus in small island popula- tions were studied by means of nightly smoked-paper tracking supple- mented by occasional livetrapping. The mice left enough track records on nights when trapped to show that they often do not enter the first trap encountered and usually move through their home ranges for some time before being trapped. This suggests that in livetrapping studies there may be little or no bias in favor of traps located near the. nest. On the other hand, the movements of mice for several nights after being trapped were markedly altered. There were many more track records than usual on such nights, probably partly because of increased activity and perhaps partly because of an altered response to the track shelters (heightened exploratory behavior). Results with P. maniculatus show that much of this increased activity occurs in daylight immediately after re- lease from traps. P. leucopus sometimes traveled far outside their former home ranges on nights after being trapped, sometimes resulting in a per- manent shift in rangfe. Because of these effects of livetrapping, this is not

A Preliminary Study of the Dietary Requirements of Tomocerus (Collembola)1

Abstract: This preliminary investigation of the feeding behavior of Tomocerus employed vivisection as well as controlled feeding in growth chambers. Tomocerus was exposed to four different diets in growth chambers which were: (1) litter and fungi, (2) fungi, (3) humus and fungi, (4) humus, litter and fungi. Fungus spores were ingested in great- er quantity than any other single food material. Organisms that were examined from the field had ingested more litter and fungal hyphae than fungal spores. The probable reason for this disparity of results between laboratory and field populations is the fact that spores are not present in great density, and at times are unavailable, under natural conditions.

Effects of Dissolved Oxygen Concentration and Light Intensity on Activity Cycles of Fishes Inhabiting Warm Springs

Abstract: The cycles of killifishes of the genus Crenichthys were studied, using trap capture rates and sound volumes as indices of activ- ity. When other factors are optimal, the fish are less active in the dark than in the light, regardless of clock time. A variety of environmental parameters could probably alter the cycles when any one factor is un- favorable. Low concentrations of dissolved oxygen result in reduced activity. Such reduction can be effected at one site where dissolved oxygen is limited, while nearby populations are active in localities that have more dissolved oxygen. Apparently at 32 C activities are adverse- ly affected by oxygen supplies below 2 ppm. cyprinodont fishes inhabiting springs and the adjacent distrilbutaries in eastern Nevada. Each of the springs inhabited by these small fishes is exceedingly clear, has a relatively constant temperature, usually a slightly alkaline pH, and a relatively low dissolved oxygen concentration at the outflow (Hubbs and Hettler, 1964). The exceedingly constant environmental temperature contrasts sharp,ly with the highly variable temperatures recorded by Barlow (1958) in his analysis of diurnal activity patterns of another desert cyprinodont, Cyprinodon macularius, near the Salton Sea. This paper will discuss activity cycles similar to those discussed by Barlow; yet the thermal stimulus is not a likely causal factor.

Helminths of bats collected in Kansas, Nebraska and Oklahoma.

Abstract: Sixty-five bats representing five, genera and eight species were examined for helminth parasites. Among the parasites collected were: (Trematoda) Plagiorchis micracanthos, P. vespertilionis, Allassogonoporus marginalis, Prosthodendrium longiforme, P. swansoni, Acanthatrium spp., Dicrocoelium rileyi, Urotrema scabridum; (Cestoda) Vampirolepis christensoni, V. roudabushi, V. gertschi; (Nematoda) Capillaria palmata, Allantoshius travassosi, A. nycticejus, Molinostrongylus delicatus. The distribution of 9 of the 15 species of helminths was extended to Kansas, Nebraska, or Oklahoma with 10 new host records. The incidence of infection with helminths in bats of different sexes and species is discussed. Intensities of infection were low in spring and peaked in the fall.