Population Biology Commons^™

Flow Reduction May Explain Sporadic Occurrence Of Craspedacusta Sowerbyi (Trachylina) Medusae, Peter P. Brussock, Lawrence D. Willis, Arthur V. Brown

Journal of the Arkansas Academy of Science

No abstract provided.

Heterogenity Of The Spawning Populations Of Surf Smelt In The State Of Washington, Raj V. Kilambi

Journal of the Arkansas Academy of Science

Biometric comparisons of three spawning populations of surf smelt, one from Pacific Coast and two from Puget Sound, were made. The Puget Sound populations (Hood Canal and Utsaladdy) were more similar to each other compared to the ocean populations. The Hood Canal and Utsaladdy smelt exhibited least distance function, D^2 , and greater overlap of meristic characters compared to the Lapush fish. It was postulated that the Puget Sound smelt populations were derived from the ocean smelt some 13,000 or more years ago.

Gametogenesis En Chthonerpeton Indistinctum (Gymnophiona: Typhlonectidae), Rafael O. De Sá, Nibia Berois

Biology Faculty Publications

RESUMEN:

Histológicamente, las gónadas de Chthonerpeton indistinctum son similares a las ya descritas para otras especies del orden Gymnophiona. Los lóbulos testiculares se hallan compartimentados en unidades estructurales denominadas lóculos. La espermatogénesis ocurre en cistos sincrónicos de células germinales. Durante la espermiogénesis se identifican cuatro estados consecutivos de desarrollo: 1) cistos de espermátidas redondeadas; 2) cistos de espermátidas arrifionadas; 3) cistos de espermátidas bastoniformes y 4) espermátidas en ramillete.

El análisis histológico de los ovarios mostró la presencia de tres estados en la maduración de los folículos ováricos. Estas etapas pueden ser identificadas de acuerdo a: 1) ubicación del folículo …

Estructura Del Ovario De Chthonerpeton Indistinctum (Reinhardt Y Lutken, 1862) (Amphibia: Gymnophiona) Durante La Gestación, Rafael O. De Sá, Nibia Berois

Biology Faculty Publications

La morfología e histología del ovario para varias especies del orden Gymnophiona ha sido reportada por Wake (1968, J. Morphol. 126, 291) y para C. indistinctum por los autores (1984, XXIV Reunión de Comunicaciones, Soc. Zool. Uruguay).

Continuando con los estudios sobre el aparato genital de esta especie vivípara, se presenta ahora la estructura del ovario durante la gestación.

Se procesaron con fines histológicos, ovarios de dos hembras grávidas colectadas en las costas de los Dep. Montevideo y San José en abril, 1983. El número de ejemplares trabajados es muy reducido dado lo difícil que resulta su colecta …

Vegetation Patterns In Relation To Topography And Edaphic Variation Nebraska Sandhills Prairie, P. W. Barnes, A. T. Harrison, S. P. Heinisch

School of Biological Sciences: Faculty Publications

Detailed studies on soil texture and moisture retention indicate a close association between edaphic features and the distribution and composition of plant communities along topographic gradients at Arapaho Prairie, a typical, semi-arid Nebraska Sandhills prairie. The vegetation characteristics of three major habitat types (ridge, slope, and valley) and several minor subtypes (swale, stable ridge, and eroding ridge) are recognized and quantitatively described. Texture analysis indicates that the soils of dune slopes and ridges are largely azonal and are very coarse with substantially lower fine fractions (silt-clay ~ 13-15%) than soils of the more lowland swale and valley sites where surfact …

Demographic Analysis And Microhabitat Relationships Of A Small Mammal Community In Clearings Of The Great Dismal Swamp, Jean Ferguson Stankavich

Biological Sciences Theses & Dissertations

Small mammals were trapped for 14 months on two grids located within a powerline right-of-way in the Great Dismal Swamp National Wildlife Refuge. During 12,354 trap nights, individuals of 10 different species were captured. They included, from highest to lowest density, Reithrodontomys humulis, Ochrotomys nuttalli, Peromyscus leucopus, Blarina brevicauda, Synaptomys cooperi, Microtus pennsylvanicus, Microtus pinetorum, Sigmodon hispidus, Mus musculus and Oryzomys palustris. The demography (densities, reproduction, home range and dispersal) of each species was analyzed when possible. Most of the species were present in relatively low densities, with a number being captured only during the latter months of the study. …

Life History Aspects Of Reithrodontomys Humulis In Southeastern Virginia, Michelle Cawthorn Chandler

Biological Sciences Theses & Dissertations

Reithrodontomys humulis, the eastern harvest mouse, is a small cricetid rodent which is common in old field communities in the eastern U.S. A live-trapping study was conducted in Suffolk, Virginia from March 1983 through February 1984 in order to learn the details of its life history and the vegetational characteristics which best describe its microhabitat. Specifically, population densities, trap-revealed survival times, home ranges, plant species composition of the study area, and vegetational structure were examined. In order to trap as many Reithrodontomys as possible, special traps which excluded animals weighing over 20 g were constructed. Densities of harvest mice …

The Role Of Colonization Predation And Season In Determining Macroinvertebrate Community Structure In A Temperate Lake, Cheryl Lynn Frew

Biological Sciences Theses & Dissertations

Field experiments were conducted to examine the effects of distance from shore, vertebrate predation, and season on macroinvertebrate colonization dynamics in a temperate lake in Suffolk, VA. In a year-long colonization study, artificial plants, half of which were caged to exclude vertebrate predators, were deployed in patches at three distances from shore (2m, 15m, 50m). Artificial plant subsamples were removed at weekly intervals over 28 days during four seasons to monitor colonization by macroinvertebrates. Colonization of artificial plants occurred more quickly in the summer and spring than in fall and winter. The interactive effect of distance from shore and cage …

Activity Levels Of Arboreal Rodents Peromysus And Ochrotomys Evaluated With Nest Cans In Seasonally Flooded Forests, John W. Walke

Biological Sciences Theses & Dissertations

The diversity and density of small mammals in the Dismal Swamp are believed to be small. To test this, four 1.96 ha grids were established and operated in the Dismal Swamp National Wildlife Refuge, from September 1981 to November 1982. Number 10 metal cans covered with plastic lids were placed as nest boxes at 0.5 to 1.5 m height on trees. A 2.5 cm hole allowed access by arboreal rodents, to each nest can. The activity level of the two arboreal rodents, Peromyscus leucopus and Ochrotomys nuttalli, was evaluated by observing types of activity ranging from presence of mice to …

Life History Patterns Of Dytiscidae In A Temporary Pool, Annabel C. Blanco

Biological Sciences Theses & Dissertations

The Dytiscidae are one of the most distributed families of aquatic Coleoptera. In addition, they comprise one of the largest families in the order. With the exception of some European species, research in the ecology/life history of the Dytiscidae has been limited.

The patterns of appearance and disappearance of Dytiscidae were studied for one growing season, February to June, 1983, in a temporary pool in the Great Dismal Swamp. Fourteen species of larvae and twenty-four species of adults were collected. Definite temporal patterns were evident in larvae of Laccophilus spp., Laccornis difformis, Liodessus affinis, Uvarus granarius, Agabetes acuductus, and Hoperius …

The Effects Of Mowing On The Rodent Community Of A Native Tall Grass Prairie In Eastern Nebraska, Cliff A. Lemen, Mary K. Clausen

University of Nebraska State Museum: Mammalogy Papers

Our results indicate that mowing, like burning, greatly reduces the use of an area by Microtus and increases the density of Peromyscus maniculatus until the grass can grow back. Depending on the rate of growth of the grass this process can take more than a year. If the prairie is mowed every year to maximize the production of hay, populations of Microtus cannot be maintained at high densities.

The study site, Nine Mile Prairie, is one of the few natural tallgrass prairies remaining in eastern Nebraska. It covers about 240 acres and is located 5 km north and 9 km …

Muscongus Bay, Marine Wildlife Inventory And Evaluation, Alan E. Hutchinson, Sandra J. Lovett

Maine Collection

Muscongus Bay, Marine Wildlife Inventory and Evaluation

by Alan E. Hutchinson and Sandra J. Lovett

Maine Department of Inland Fisheries and Wildlife

Augusta, Maine, February, 1984.

Contents: Preface / Acknowledgment / List of Tables / List of Figures / Introduction / Resource Inventory / Resource Evaluation / Resource Impact Assessment / Conclusions and Recommendations / References / Appendix

Effects Of Commercial Fish Removal On Sport Fish Populations In Two Arkansas Reservoirs, Tommie Crawford

Journal of the Arkansas Academy of Science

Commercial netting occurred October through April, 1971-1976 on Nimrod Lake and from October through April, 1973-1977 on Blue Mountain Lake in west central Arkansas. Using 7.6 cm or larger mesh gill and/or trammel nets, commercial fishermen harvested commercial fishes (buffalofishes [Ictiobus spp.]; common carp [Cyprinus carpio], carpsuckers [Carpiodes spp.]; drum [Aplodinotus grunniens]; gars [Lepisosteus spp.]; suckers [Catostomidae); and catfishes [Ictalurus spp. and Pylodictis olivaris]). During the study period, cove rotenone samples were conducted on an annual basis. Fishes collected were placed into age classes and enumerated. Data were then grouped into general categories (black basses [Micropterus spp], crappie [Pomoxis spp.], …

Rabbit Kitten Survival In The South-West, D R. King

Journal of the Department of Agriculture, Western Australia, Series 4

In the South-West of Western Australis reliable winter rains allow the rabbit breeding season to extend through winter and spring, and thus a large number of kittens are produced each year.

Studies on the biology of rabbits at Cape Naturaliste (270 kilometres south-west of Perth) and Chidlow (40 kilometres east of Perth in the Datling Range) have shown that at these sites each doe produces about 30 and 27 kittens respectively a year. If all these youg rabbits survived, there would be a 15-fold increase in numbers. Within a short time the State would be covered "wall to wall" by …

Rabbits North Of Carnarvon, D R. King

Journal of the Department of Agriculture, Western Australia, Series 4

In Westeern Australia rabbits are mainly a pest along the south-western coastal parts of the State, but there are populations north of the Tropic of Capricorn. Rabbits after crossing the Nullarbour plain from South Australia and colonising the South-West of the State, were reported to have reached the west coast near Geraldton by 1912 and then spread northwards.

There is little information on the biologhy of rabbits in the northan parts of their range, but pastoralists in some areas are concerned about erosion and damage to vegetation on their stations when rabbits reach high numbers.

The Agricultural Protection Board undertook …

Keeping Starlings Out Of W.A, John L. Long

Journal of the Department of Agriculture, Western Australia, Series 4

In Europe and North America huge flocks of starlings cause millions of dollars worth of damage to grain and fruit crops each year and large sums of money are spent trying to control them.

Starlings were introduced into australia in the late 1890s when more than 200 birds were released near Melbourne. They are now well established over much of eastern Australia, ranging from central Queensland, south to Tasmania and along the Great Australian Bight to the South Australian-Western Australian border, occasionally crossing it and sometimes moving as far west as the Esperance region on the south coast.

Some people …

Protection Of Endangered Gray Bat (Myotis Grisescens) Colonies In Arkansas, Michael J. Harvey

Journal of the Arkansas Academy of Science

No abstract provided.

Effect Of The Payment-In-Kind (Pik) Program On The Psorophora Columbiae Mosquito Population Of A Northeast Arkansas Ricefield Community, Larry A. Olson, Julia L. Reid

Journal of the Arkansas Academy of Science

No abstract provided.

Influence Of Degray Reservoir On Zooplankton Populations In The Caddo And Ouachita Rivers, Ralph B. Roseberg, Mark Karnes

Journal of the Arkansas Academy of Science

No abstract provided.

The Effects Of Dredged Materials On The Copeod, Acartia Tonsa, Renee Suzanne Crouch

Biological Sciences Theses & Dissertations

A study was conducted to determine the potential impact of open ocean disposal of sediments dredged from a highly industrialized seaport. Sediments from three potential dredge sites along the Southern Branch of the Elizabeth River, Hampton Roads, Virginia were evaluated for acute toxicity. The suspended particulate fractions of dredged materials were tested in a series of 96-hour, static bioassays using the calanoid copepod, Acartia tonsa Dana. Significant mortalities were observed for all three sites with the sediments from the most heavily industrialized site producing immediate and severe mortality. Analysis of results indicates that mortality was highly related to the volatile …

The Effects Of The Mud Snail Ilyanassa Obsoleta (Say) Upon The Benthic Community Of Broad Bay, Virginia, Wick Timothy Harlan

Biological Sciences Theses & Dissertations

The effects of the presence of the mud snail Ilyanassa obsoleta (Say) upon the benthic community of Broad Bay, Virginia were examined through artificial removal and exclusion of the snail and artificial increase of the snail population. The enclosure treatment exhibited a significantly higher number of macrofaunal individuals than the control. The control had a significantly higher number of meiofaunal individuals than either treatment. There were no significant differences for the chlorophyll a. The increase in macrofauna and corresponding decrease in meiofauna were probably due to cage effects and not snail densities. The presence of the fences can act as …

The Effects Of Dominant Species Removal On Subtidal Community Development, H. Russell Barker Jr.

Biological Sciences Theses & Dissertations

Acrylic panels were used to follow the development of the fouling community at Channel Points, Lynnhaven Bay, Virginia, from April through October 1979. The roles of Membranipora tenuis, an encrusting ectoproct, and Molgula manhattensis, a solitary tunicate, were studied by removing each species from the developing community on a weekly basis.

Early colonization was dominated by Membranipora followed by Corophium spp. (Amphipoda), Polydora ligni (Polychaeta), and Balanus eberneus (Arthropoda). Molgula colonized the panels later in the study and became a dominant occupier of primary space by the end of the study.

The removal of Membranipora and Molgula …

Federal Government Assaults Animals On Wildlife Refuges

Close Up Reports

The welfare of America's wildlife and refuges is being sold for economic gain and recreational pleasure to hunters, trappers, and commercial developers. To date, there are 414 refuges composed of over 86 million acres stretching from the Arctic to the Florida Keys and from Maine to American Samoa. Almost all of these refuges have been touched in some way by natural gas exploration, predator control, pesticides, and commercial farming, ranching, and lumber industries. Over one half of all refuges are open to either hunting or trapping...or both.

All laws and regulations concerning activities on wildlife refuges stipulate that there must …

Solving The Pet Overpopulation Problem

Close Up Reports

Because of the short pregnancies and large litters of dogs and cats, one individual female with all her female offspring reproducing similarly can be the source of over 4,000 new lives within seven years. Some of these animals will find homes complete with laps to sit on and fireplaces to enjoy, but millions of other perfectly healthy dogs and cats won't be so lucky. The overabundance of these potential pets tends to cheapen the intrinsic value of each individual animal in the eyes of the general public. The swelling problem causes some people to use cruel methods of disposing of …

A Quantitative Study Of The Aquatic Macroinvertebrates In An Irregularly Flooded Salt Marsh, Smith Island, Virginia, Leon L. Robert Jr.

Biological Sciences Theses & Dissertations

Little is known about the aquatic macroinvertebrate community structure in coastal salt marshes. This study investigated the aquatic macroinvertebrate community structure in a coastal Virginia salt marsh. Sixteen samples were taken weekly from two different sites on Smith Island, Virginia, from April to mid-October 1982. Bimonthly samples were taken during the months March and November due to low density of organisms and reduced growth rates at these times.

A total of 46 taxa were collected with 17 occurring regularly, indicating a relatively diverse fauna. Wide fluctuations in the physical parameters were observed; however, temporal changes in the macroinvertebrate community cannot …

Twenty-Two New Species Of Spiders For The Arkansas Checklist, Mary L. Beck, Peggy Rae Dorris

Journal of the Arkansas Academy of Science

No abstract provided.

Abundance And Distribution Of Large Mammals In The Upper Ogun Game Reserve, Oyo State, Nigeria, T. A. Afolayan, K. R. N. Milligan, S. O. Salami

Nature Collection

In this study, three indirect methods [counts of animal droppings, footprints, and tracks) were used as indices to estimate the abundance and distribution of large mammals in the Upper Ogun Game Reserve, which is located in a typical Southern Guinea savanna zone of Nigeria. Thirteen animal species were recorded; kob, bushbuck, hartebeest, roan antelope and duicker were the most abundant. The distribution of large mammals appears to be controlled by several factors: accessibility to the River Ogun [the main source of water in the reserve), availability of food and cover, and the extent of illegal hunting.

An analysis of questionnaires …

Feral Dogs Of The Galapágos Islands: Impact And Control, Bruce D. Barnett, Robert L. Rudd

Ecology Collection

Organisms introduced onto insular ecosystems, after they have become established, frequently increase to destructive numbers. Several species of mammals introduced onto the Galapagos Islands illustrate this ecological axiom. For example, domestic dogs intentionally introduced now exist as three major types: domestic, free--ranging or pariah, and feral. Problems derived from their presence are most apparent on the islands of Santa Cruz and lsabela. Feral and pariah dogs are both scavengers and predators. While other introduced mammals (chiefly feral cattle and pigs) have served as prey, in recent years severe depredations on the unique endemic Ga/apagan fauna have been caused by the …

Stray-Dog Control In Cyprus: Primitive And Humane Methods, Kyriacos Polydorou

Hunting Collection

In Cyprus, a dog control scheme was started in 1971 within the context of an all-inclusive anti-echinococcosis campaign. At the time, it was estimated that there were more than 100,000 dogs in the island, almost all of which were strays (even many of those that were purportedly "owned"]. These had been identified as infectious agents of echinococcosis in Cyprus (the average surgical incidence in humans, over the 30-year period prior to 1970, was 12.9/100,000]. The destruction of stray dogs is accomplished by using guns that fire a syringe containing a euthanizing drug. In the past (prior to 1970), various inhumane …

Selecting A Spay/Neuter Program For Animal Control In The City Of Charlotte, Diane Quisenberry, Mary Elizabeth Clapp

Hunting Collection

The City of Charlotte, NC, in attempting to determine the best kind of program for reducing its increasing populations of unwanted dogs and cats, examined a full range of possible options for limiting these populations. Five measures for population control were considered: spay/neuter surgery, euthanasia, physical restraint, mechanical contraception, and chemical contraception. It was concluded that a spay/neuter program that incorporated educational and legislative components would be the most effective means of large-scale population control, although other methods like euthanasia would still have to be used. Based on a survey of a number of cities with spay/neuter programs in place, …