Life Sciences Commons^™

Nectar Secondary Compounds Affect Self-Pollen Transfer: Implications For Female And Male Reproduction, Rebecca E. Irwin, Lynn S. Adler

Dartmouth Scholarship

Pollen movement within and among plants affects inbreeding, plant fitness, and the spatial scale of genetic differentiation. Although a number of studies have assessed how plant and floral traits influence pollen movement via changes in pollinator behavior, few have explored how nectar chemical composition affects pollen transfer. As many as 55% of plants produce secondary compounds in their nectar, which is surprising given that nectar is typically thought to attract pollinators. We tested the hypothesis that nectar with secondary compounds may benefit plants by encouraging pollinators to leave plants after visiting only a few flowers, thus reducing self-pollen transfer. We …

Paddlefish Egg Deposition In The Lower Yellowstone River, Montana And North Dakota, Shannon E. Miller, Dennis L. Scarnecchia, Steven R. Fain

The Prairie Naturalist

We used passive egg collectors during May, June, and July of2003 and 2004 in the lower 50 river kiiometers (rkm) of the Yellowstone River, eastern Montana and western North Dakota, to detect egg deposition by spawning paddle fish (Polyodon spathula). Sampling yielded 292 eggs (46 in 2003 and 246 in 2004). All egg collections in 2003 occurred on the descending limb of the spring hydrograph but 99% of egg collections in 2004 occurred before the spring hydrograph began to descend. Catch-per-unit-effort (CPUE) in 2004 was about four times that of 2003. A combination of river conditions, in addition …

Reproductive Effort In Squirrels: Ecological, Phylogenetic, Allometric, And Latitudinal Patterns, Virginia Hayssen

Biological Sciences: Faculty Publications

The distinctive features of reproduction in squirrels are the lack of allometric influences on the duration of reproductive investment; the strong allometric influences on offspring mass; and a trade-off between number and size of young, suggesting an important developmental component to reproduction. Lengths of gestation and lactation do not vary with body size but neonatal and weaning mass do. Apparently, the major constraint on reproduction in squirrels is not resources per se (food, calories, minerals, or water) but rather the length of time such resources are available. Squirrels adjust growth rate to fit the timing of resource abundance. Within the …

Genome-Wide Analysis Of The Interaction Between The Endosymbiotic Bacterium Wolbachia And Its Drosophila Host, Zhiyong Xi, Laurent Gavotte, Yan Xie, Stephen L. Dobson

Entomology Faculty Publications

BACKGROUND: Intracellular Wolbachia bacteria are obligate, maternally-inherited, endosymbionts found frequently in insects and other invertebrates. The success of Wolbachia can be attributed in part to an ability to alter host reproduction via mechanisms including cytoplasmic incompatibility (CI), parthenogenesis, feminization and male killing. Despite substantial scientific effort, the molecular mechanisms underlying the Wolbachia/host interaction are unknown.

RESULTS: Here, an in vitro Wolbachia infection was generated in the Drosophila S2 cell line, and transcription profiles of infected and uninfected cells were compared by microarray. Differentially-expressed patterns related to reproduction, immune response and heat stress response are observed, including multiple genes that have …

Reproductive Allometry And The Size-Number Trade-Off For Lizards, Eric Charnov, Robin Warne

Biology Faculty & Staff Publications

The yearly reproductive allocation shows a 0.75 allometry with adult size across lizard species.

A Sex Difference In Seasonal Timing Of Birth In A Livebearing Fish, Eric T. Schultz

EEB Articles

Sex differences in seasonal timing include differences in hatch- or birth-date distribution and differences in the timing of migration or maturation such as protandrous arrival timing (PAT), which is early male arrival at breeding sites. I describe a novel form of protandrous arrival timing, as a sex difference in birth-date distribution in a live-bearing fish (Dwarf Perch, Micrometrus minimus). In this species, birth coincides with arrival at breeding sites because newborn males are sexually active. A series of samples of pregnant females and young of year was collected in Tomales Bay, CA. I analyzed the daily age record in otoliths …

Reproductive Health Of The Florida Flock Of Introduced Whooping Cranes, Marilyn G. Spalding, Martin J. Folk, Stephen A. Nesbitt

Proceedings of the North American Crane Workshop

We examined the reproductive parameters of the introduced non-migratory flock of whooping cranes in Florida. Of 289 cranes introduced, 67 males and 65 females survived at least 3 years. The first behavioral pairs appeared in 1995, and eggs were first laid in 1999. In total, eggs were laid in 47 nests, 17 chicks hatched, and 4 young fledged by 2005. Severe drought conditions through 2001 were thought to be the reason for low reproductive nest success. In 2003 nesting conditions improved and 71% of nests with eggs, hatched chicks. During the next 2 years, with continued wet conditions, the proportion …

Survival, Movements, Social Structure, And Reproductive Behavior During Development Of A Population Of Reintroduced, Migratory Whooping Cranes, Richard P. Urbanek, Lara E. A. Fondow

Proceedings of the North American Crane Workshop

An effort to reintroduce a migratory population of whooping cranes (Grus americana) into eastern North America began in 2001. During 2001-2004, 53 juveniles were released. All chicks were hatched at Patuxent Wildlife Research Center, Maryland, and transferred to Necedah National Wildlife Refuge (NWR), Wisconsin. Chicks were costume/isolation-reared and, with few exceptions, trained to follow ultralight aircraft, which led them to Chassahowitzka NWR, Central Gulf Coast of Florida. All individuals successfully returned to Central Wisconsin during their first spring migration except for the following: 5 individuals that were unable to navigate around Lake Michigan after taking an easterly migration …

2008 Nebraska Beef Cattle Report Summaries, Richard J. Rasby, Galen E. Erickson, Dennis R. Brink

University of Nebraska-Lincoln Extension: Historical Materials

Reports on recent beef research are briefly summarized in this publication. Summaries of the research featured in the 2008 Beef Report appear here. Topics include cow-calf, growing, finishing and beef products.