Population Biology Commons^™

Feeling The Heat? Substantial Variation In Temperatures Does Not Affect The Proportion Of Males Born In Australia, Barnaby J. Dixson, John Haywood, Philip J. Lester, Diane K. Ormsby

Human Biology Open Access Pre-Prints

The global proportion of male births has been shown to vary with climate, with a higher proportion of male births documented in colder climates. Here we examined the hypothesis that ambient temperature predicts fluctuations in the proportion of male births in Australia and within seven Australian states using historical annual data spanning 1910-2009. We predicted that within states with tropical ambient temperatures the proportion of male births would decrease when ambient temperatures are higher. Considering the national composite births for the whole of Australia first, the proportion of males born ranged only from 0.510 to 0.517. We observed no relationship …

Genetic Variation Of X-Strs In The Wichí Population From Chaco Province, Argentina, Laura Angela Glesmann, Pablo Francisco Martina, Cecilia Inés Catanesi

Human Biology Open Access Pre-Prints

The Wichí people from Chaco province inhabit the region called Impenetrable Chaqueño, where the climatic conditions are extreme. Besides the scarce communication with the main urban centers, the cultural patterns of the Wichí cause these communities to live in certain degree of isolation. The effect of this situation is an increased genetic differentiation from other populations, as it was observed through autosomal and Y chromosome markers. However, the genetic variation of X chromosome has not been fully analyzed yet. The patterns of allele distribution of different markers of X chromosome can be highly informative in comparative studies, because its special …

The Genus Odontophrynus (Anura: Odontophrynidae): A Larval Perspective, Filipe Augusto C. Do Nascimento, Tamí Mott, José A. Langone, Christine A. Davis, Rafael O. De Sá

Biology Faculty Publications

The genus Odontophrynus consists of 11 species of medium-sized frogs distributed across south and east South America. This study examines and describes the chondrocrania and oral cavities of 0. americanus, 0. maisuma, 0. carvalhoi, and 0. cu/tripes, and reviews current knowledge about the larval external morphology of the genus. Twenty-one tadpoles were cleared and double-stained for chondrocranium description and five tadpoles were dissected for analysis in a scanning electron microscope. The presence of a tectum parientale may be considered here as a putative synapomorphy of the genus. The 0. americanus and 0. cu/tripes species groups were partially differentiated by the …

Big Babies, Big Mammas?: Relationship Of Leatherback Hatchling Size And Mother Size, Shane Morales, Violet Campbell, Kelly Stewart

STAR Program Research Presentations

Individual leatherback hatchlings vary in size when compared to individuals from other nests, as well as individuals from the same nest. It is thought that many factors affect hatchling size but that one of the most influential factors is maternal size. Of all the aspects of a mother which could affect hatchling size, evidence for question concerning influence of mother size is determinable within the field using minimal tools and basic statistical analysis. If a direct correlation exists between mother size and hatchling size then the claim can be made that larger mothers produce larger offspring while smaller mothers produce …

Jellyfish Identification And Quantification In The San Francisco Estuary, Amalia Borson, Lindsay L. Sullivan, Wim Kimmerer

STAR Program Research Presentations

As potential predators and competitors of plankton-eating fish, jellyfish have the potential to negatively impact fish populations. Jellyfish were collected weekly with plankton tows from the RombergTiburonCenterpier in Tiburon, CA. Since some jellyfish were too small to identify, one tow was collected and preserved to record abundances, and a second tow was collected to rear jellyfish until distinguishing characteristics were visible enough for identification. Jellyfish in the preserved tows were then identified, measured, and counted, and their abundance (number m^-3) was calculated. Jellyfish from the second tows were reared in plastic buckets that were lightly bubbled using aquarium …

Greater Prairie-Chicken Nest Success And Habitat Selection In Southeastern Nebraska, Ty W. Matthews, Andrew J. Tyre, J. Scott Taylor, Jeffrey J. Lusk, Larkin A. Powell

School of Natural Resources: Faculty Publications

Greater prairie-chickens (Tympanuchus cupido pinnatus) are reported to benefit from grasslands created through the Conservation Reserve Program (CRP). Prairie-chicken population size increased noticeably in southeastern Nebraska after >15% of county-level landscapes were converted to CRP grasslands. But, the mechanisms behind the increase in population size are not well understood, and managers and policy makers could benefit from evidence of CRP’s relative contribution to populations of prairie-chickens. Therefore, our objectives were to characterize the relations of vegetation structure and composition with prairie-chicken nest-site selection and nest survival rates at both the macrohabitat (within landscape of study site) and microhabitat …

Cause And Impacts Of The Early Season Collapse Of Lilium Grayi (Gray’S Lily), On Roan Mountain, Tn/Nc, Russell J. Ingram

Electronic Theses and Dissertations

A population of the rare Southern Appalachian endemic species Lilium grayi, (Gray’s lily) Roan Mountain, TN/NC was monitored for 2 years to determine the cause and impact of an early season collapse. High concentrations of the Lilium spp. host-specific fungal phytopathogen, Pseudocercosporella inconspicua (G. Winter) U. Braun were associated with 19/20 symptomatic and 0/30 asymptomatic plants. Strength of the association between pathogen and disease and the replication of disease symptoms in 4/4 healthy hosts showed that P. inconspicua was the causal agent of the disease referred to as lily leaf spot. Disease had a severe impact on the population …

Reproductive Isolation And Cryptic Introgression In A Sky Island Enclave Of Appalachian Birds, Gene D. Sattler, Michael J. Braun

Faculty Publications and Presentations

Reproductive isolation is central to the speciation process, and cases where the strength of reproductive isolation varies geographically can inform our understanding of speciation mechanisms. Although generally treated as separate species, Black-capped chickadees (Poecile atricapillus) and Carolina chickadees (P. carolinensis) hybridize and undergo genetic introgression in many areas where they come into contact across the eastern United States and in the northern Appalachian Mountains. The Great Smoky Mountains harbor the last large breeding population of atricapillus in the southern Appalachians, isolated from the species’ main range by nearly 200 km. This population is believed to be reproductively isolated from local …

The Interactive Effects Of Multiple Stressors On Lithobates Catesbeianus And Anaxyrus Americanus, Matthew Kyle Holden

Graduate Theses and Dissertations

Amphibian populations worldwide have experienced dramatic declines, and many species have already become locally, regionally, or globally extirpated with thousands more being threatened with extinction. These declines have occurred more rapidly in amphibians than any other group of vertebrates, which is especially concerning to scientists because amphibians serve as indicator species of overall environmental health. Major causes for amphibian declines are discussed in Chapter 1 and include: habitat modification and destruction, commercial over-exploitation, introduced species, environmental contaminants, global climate change, and infectious diseases.

Chapter 2 discusses the major research aspects of the thesis by examining the interactive effects of multiple …

Genetic And Morphological Variation In Taeniatherum Caput-Medusae (Medusahead): Taxomonic Diversity, Geographic Origins, Multiple Introductions And Founder Effects, Morgan Lindsey Peters

Boise State University Theses and Dissertations

Invasive species are novel to a region, thus their timely and accurate identification is a critical first step in recognizing and managing the threats that they may present in their new habitats. Accurate identification of an introduced species in its new range can prove difficult however for a species that displays taxonomic complexity in its native range, i.e. consists of multiple, morphologically similar subspecies.

Across its native range, Taeniatherum caput-medusae (medusahead) exhibits taxonomic complexity. Three subspecies have been recognized: T. caput-medusae ssp. caput-medusae, T. caput-medusae ssp.asperum, and T. caput-medusae ssp. crinitum. While subspecies …

Ecology And Structure Of Black Bear (Ursus Americanus) Populations In The Interior Highlands Of Arkansas, Thea Vandervelde Kristensen

Graduate Theses and Dissertations

In the Interior Highlands of Arkansas, Missouri, and Oklahoma, over-harvest, extensive logging, and reductions of habitat availability by other means contributed to the decline of black bears (Ursus americanus). Bears were extirpated from the majority of the region by the 1940's Oklahoma by 1915 and from Missouri by 1931. From 1958-1968, the Arkansas Game and Fish Commission undertook a reintroduction to the Ouachita and the Ozark National Forests in Arkansas. The successful growth and expansion of the released population caused these efforts to be considered one of the most successful reintroductions of carnivores. In this dissertation, I sought to examine …

Exploitation Of Channel Catfish In Nebraska Flood-Control Reservoirs, Christopher Lee Wiley

School of Natural Resources: Dissertations, Theses, and Student Research

Channel catfish Ictalurus punctatus, is a popular sportfish in North America, and is the third most-sought fish species in Nebraska. Exploitation rates of channel catfish populations have been estimated to be substantial in states neighboring Nebraska. Despite the popularity of channel catfish, little is known about the exploitation of channel catfish populations in Nebraska. The objectives of this study were to estimate the exploitation rates of channel catfish populations, identify the length bias of angling for channel catfish, and identify the self-imposed length limits for channel catfish at flood-control reservoirs of Nebraska. The software package Program Mark was used to …

The Birds Of Nebraska, Revised Edition 2013, Paul A. Johnsgard

Zea E-Books Collection

This summary of the birds of Nebraska has been restricted to those species that have been convincingly reported at least once in Nebraska from historic time to the present. It has also been modified in its current revision to conform very closely in that regard to the most recent Nebraska Ornithologists’ Union’s “Official List of the Birds of Nebraska” (Brogie, 2010; NOU Records Committee, 2011 and annual updates). The N.O.U.’s official state list of birds (455 species as of 2013, including 329 “regular” species, 42 of “casual” occurrence, 68 accidentals, and six extinct or extirpated species) is based on actual …

Climate Change And Plant Demography In The Sagebrush Steppe, Aldo Compagnoni

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.

Policy On Restocking And Stock Enhancement In Western Australia, Department Of Fisheries Western Australia.

Fisheries Management Papers

The practice of releasing hatchery-reared fish into existing populations to augment fishing (stock enhancement) or restore depleted spawning biomass (restocking) has occurred around the world for decades with varying degrees of success. The underpinning concept is to produce and release fish into wild populations to increase their abundance, catch rates and/or fishery yields

If restocking and stock enhancement activities are to be successful, they should have clear objectives and be well planned and targeted at situations where there is a reasonable expectation of having a beneficial effect.

The Identity Of Rana Margaritifera Laurenti, 1768 (Anura, Bufonidae), Esteban O. Lavilla, Ulisses Caramaschi, José A. Langone, José P. Pombal Jr., Rafael O. De Sá

Biology Faculty Publications

Rana margaritifera was described by Laurenti in 1768 and currently is associated to the genus Rhinella, under the combination Rhinella margaritifera. Currently, the R. margaritifera species group consists of 16 recognized species. Further-more, many additional species have been suggested to exist in this group which highlights the ambiguity surrounding the identity of Rhinella margaritifera and impend further description of the species in this group. After an exhaustive bibliographic review, we concluded that the recent designation of a lectotype for R. margaritifera is invalid according with Art. 73, ICZN, 1999. Herein, we designate and provide the description of a …

A Hands-On Activity To Introduce The Effects Of Transmission By An Invasive Species, Barbara May

Biology Faculty Publications

This activity engages students to better understand the impact of transmission by invasive species. Using dice, poker chips, and paper plates, an entire class mimics the spread of an invasive species within a geographic region. The activity can be modified and conducted at the K-16 levels.

Larval Performance And Kill Rate Of Convergent Ladybird Beetles, Hippodamia Convergens, On Black Bean Aphids, Aphis Fabae, And Pea Aphids, Acyrthosiphon Pisum, Travis M. Hinkelman, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

Generalist predator guilds play a prominent role in structuring insect communities and can contribute to limiting population sizes of insect pest species. A consequence of dietary breadth, particularly in predatory insects, is the inclusion of low-quality, or even toxic, prey items in the predator’s diet. Consumption of low-quality prey items reduces growth, development, and survival of predator larvae, thereby reducing the population sizes of generalist predators. The objective of this paper was to examine the effect of a suspected low-quality aphid species, Aphis fabae (Scopoli) (Hemiptera: Aphididae), on the larval performance of an abundant North American predator, Hippodamia convergens (Guérin-Méneville) …

Genetic Structure Of The Copperhead (Viperidae: Agkistrodon Contortrix Mokasen) At Its Most Northern Distribution, Brenna Aaren Levine

Graduate Theses and Dissertations

The focus of molecular studies in North American pitvipers has been on species that warrant conservation concern, such as Timber (Crotalus horridus) and Massasauga rattlesnakes (Sistrurus catenatus). Scant effort has been directed towards the molecular ecology of the Copperhead (Agkistrodon contortrix), other than to evaluate male reproduction in a laboratory setting and phylogenetic history. Thus, employing DNA-based molecular techniques to study the natural history of A. contortrix will broaden our knowledge of molecular ecology in North American pitvipers, and particularly in a non-threatened species that can serve as a surrogate for threatened and endangered …

Partners In Spread Prevention, Nancy C. Balcom

Wrack Lines

Working together to stop the spread of aquatic invasive species.