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Full-Text Articles in Life Sciences

Sex‐Biased Survival Contributes To Population Decline In A Long‐Lived Seabird, The Magellanic Penguin, Natasha J. Gownaris, P. D. Boersma Jan 2019

Sex‐Biased Survival Contributes To Population Decline In A Long‐Lived Seabird, The Magellanic Penguin, Natasha J. Gownaris, P. D. Boersma

Environmental Studies Faculty Publications

We developed a Hidden Markov mark–recapture model (R package marked) to examine sex‐specific demography in Magellanic Penguins (Spheniscus magellanicus ). Our model was based on 33 yr of resightings at Punta Tombo, Argentina, where we banded ~44,000 chicks from 1983 to 2010. Because we sexed only 57% of individuals over their lifetime, we treated sex as an uncertain state in our model. Our goals were to provide insight into the population dynamics of this declining colony, to inform conservation of this species, and to highlight the importance of considering sex‐specific vital rates in demographic seabird studies. Like many other …


Population And Ecological Characteristics Of The Dice Snake, Natrix Tessellata(Laurenti, 1768), In Lower Portions Of The Vrbanja River(Republic Of Srpska, Bosnia And Herzegovina), Goran Sukalo, Sonja Nikolic, Dejan Dmitrovic, Ljiljana Tomovic Jan 2019

Population And Ecological Characteristics Of The Dice Snake, Natrix Tessellata(Laurenti, 1768), In Lower Portions Of The Vrbanja River(Republic Of Srpska, Bosnia And Herzegovina), Goran Sukalo, Sonja Nikolic, Dejan Dmitrovic, Ljiljana Tomovic

Turkish Journal of Zoology

Despite their comparative richness and accessibility in the Republic of Srpska and in Bosnia and Herzegovina in general, population studies of reptiles have not been performed in Srpska until recently. For example, one of the most common snake species in this area is the dice snake; nevertheless, previous studies have only reported its distribution. The aim of the present study was to analyze characteristics of the dice snake population along the Vrbanja River. Animals were processed during 2011 throughout their activity period. In total, 199 individuals of all ages were collected. We observed substantial differences in numbers of animals captured …


Relative Competitive Abilities, Intersexual Overyielding, And Population Sex Ratio Changes In A Bryophyte, Zachary Stanley Jan 2019

Relative Competitive Abilities, Intersexual Overyielding, And Population Sex Ratio Changes In A Bryophyte, Zachary Stanley

Theses and Dissertations--Biology

Unequal sex ratios are widespread in dioecious plants and understanding their cause is important to understanding fundamental aspects of their population dynamics, and yet what causes biased sex ratios in plants is still poorly understood. Competition experiments have been used in plants to predict the outcome of species interactions, but they have rarely been used to help explain sex ratio bias. This study used a response surface competition design to measure the relative competitive abilities of the sexes of the bryophyte Marchantia inflexa (a thallus liverwort of Marchantiaceae) to predict the outcome of competition before the onset of sexual reproductive …


Spatiotemporal Distribution And Population Structure Of Clibanarius Symmetricus (Randall, 1840) (Crustacea, Diogenidae) In An Amazon Estuary, Ana Carolina Melo Rodrigues, Jussara Moretto Martinelli-Lemos Jan 2019

Spatiotemporal Distribution And Population Structure Of Clibanarius Symmetricus (Randall, 1840) (Crustacea, Diogenidae) In An Amazon Estuary, Ana Carolina Melo Rodrigues, Jussara Moretto Martinelli-Lemos

Turkish Journal of Zoology

Rocky outcrops in the intertidal zones of estuaries often contain a highly diverse microbenthic community which includes the hermit crab, Clibanarius symmetricus, an abundant species on the equatorial Amazon coast. However, the ecology of this anomuran is poorly understood. Given this, the present study investigated the spatiotemporal distribution and structure of the C. symmetricus populations that inhabit the rocky outcrops of the Marapanim estuary in northern Brazil. Samples were collected monthly over a yearly cycle covering both the dry and rainy seasons in the upper and lower midlittoral zones during low tide. The distribution and abundance of C. symmetricus were …