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Articles 871 - 900 of 2324

Full-Text Articles in Behavior and Ethology

Consequences Of Porcine Zona Pellucida Immunocontraception To Feral Horses, Cassandra M.V. Nuñez Jan 2018

Consequences Of Porcine Zona Pellucida Immunocontraception To Feral Horses, Cassandra M.V. Nuñez

Human–Wildlife Interactions

Porcine zona pellucida (PZP) immunocontraception was developed to provide a more humane, effective, and inexpensive method of population regulation for wildlife species. It has been used to regulate populations of several species including white tailed deer (Odocoileus virginianus), elk (Cervus elaphus ), black bear (Ursus americanus ), and the feral horse (Equus ferus caballus) with varying levels of success. Early studies on Assateague Island National Seashore, Maryland, USA, suggested PZP was as an ideal form of fertility control because it reduced the likelihood of conception to


Estimating Exploitation Rates In The Alabama Red Snapper Fishery Using A High-Reward Tag–Recapture Approach, Dana K. Sackett, Mattgew Catalano, J. Marcus Drymon, Sean P. Powers, Mark Albins Jan 2018

Estimating Exploitation Rates In The Alabama Red Snapper Fishery Using A High-Reward Tag–Recapture Approach, Dana K. Sackett, Mattgew Catalano, J. Marcus Drymon, Sean P. Powers, Mark Albins

University Faculty and Staff Publications

Accurate estimates of exploitation are essential to managing an exploited fishery. However, these estimates are often dependent on the area and vulnerable sizes of fish considered in a study. High-reward tagging studies offer a simple and direct approach to estimating exploitation rates at these various scales and in examining how model parameters impact exploitation rate estimates. These methods can ultimately provide a better understanding of the spatial dynamics of exploitation at smaller local and regional scales within a fishery—a measure often needed for more site-attached species, such as the Red Snapper Lutjanus campechanus. We used this approach to tag 724 …


Foraging Ecology Of A Winter Bird Community In Southeastern Georgia, Rachel E. Mowbray Jan 2018

Foraging Ecology Of A Winter Bird Community In Southeastern Georgia, Rachel E. Mowbray

College of Graduate Studies: Theses & Dissertations

Classical views on community structure emphasized deterministic processes and the importance of competition in shaping communities. However, the processes responsible for shaping avian communities remain controversial. Attempts to understand distributions and abundances of species are complicated by the fact that birds are highly mobile. Many species migrate biannually between summer breeding grounds and wintering grounds. The goal of this study was to test four hypotheses that attempt to explain how migratory species integrate into resident assemblages of birds (Empty-Niche Hypothesis, Competitive-Exclusion Hypothesis, Niche-Partitioning Hypothesis, and Generalist-Migrant Hypothesis). I collected data on birds foraging during the winter of 2017-2018 in Magnolia …


Ecological Uncertainty Influences Vigilance As A Marker Of Fear, Laurence E. A. Feyten, Grant E. Brown Jan 2018

Ecological Uncertainty Influences Vigilance As A Marker Of Fear, Laurence E. A. Feyten, Grant E. Brown

Animal Sentience

We expand on the factors that may shape the predictability of risk and the potential impacts on the links between vigilance and fear, primarily in aquatic prey communities. Uncertainty in predation risks has been shown to induce increased levels of neophobia among prey. As a result of this phenotypically plastic response, prey are faced with risk assessment cues that may vary widely in their reliability. We argue that decomposing predictability may provide useful insights into the relationship between vigilance and fear.


Competing Activities As Measures Of Fear And Vigilance, Ferenc Mónus Jan 2018

Competing Activities As Measures Of Fear And Vigilance, Ferenc Mónus

Animal Sentience

In animal behavioural research on vigilance, visual signs of alertness are usually used to estimate perceived risk (an internal “fear” state) of free-ranging animals. Different measures of vigilance and competing activities (e.g., predator vigilance, conspecific vigilance, feeding, food handling) provide clues for better understanding vigilance behaviour. How efficiently does an animal in a vigilant/non-vigilant posture devote attention to threats or invest in other activities, such as searching for or handling food? Several species regularly withdraw to a sheltered spot when feeding in an abundant food patch, spending short periods in complete safety. Frequencies of feeding interruptions or false-alarm flights provide …


Distance Models As A Tool For Modelling Detection Probability And Density Of Native Bumblebees, Darin J. Mcneil, Clint R. V. Otto, Erin L. Moser, Katherine R. Urban‐Mead, David E. King, Amanda D. Rodewald, Jeffery L. Larkin Jan 2018

Distance Models As A Tool For Modelling Detection Probability And Density Of Native Bumblebees, Darin J. Mcneil, Clint R. V. Otto, Erin L. Moser, Katherine R. Urban‐Mead, David E. King, Amanda D. Rodewald, Jeffery L. Larkin

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

Effective monitoring of native bee populations requires accurate estimates of population size and relative abundance among habitats. Current bee survey methods, such as netting or pan trapping, may be adequate for a variety of study objectives but are limited by a failure to account for imperfect detection. Biases due to imperfect detection could result in inaccurate abundance estimates or erroneous insights about the response of bees to different environments. To gauge the potential biases of currently employed survey methods, we compared abundance estimates of bumblebees (Bombus spp.) derived from hierarchical distance sampling models (HDS) to bumblebee counts collected from fixed‐area …


An Historical Overview And Update Of Wolf-Moose Interactions In Northeastern Minnesota, L. David Mech, John Fieberg, Shannon M. Barber-Meyer Jan 2018

An Historical Overview And Update Of Wolf-Moose Interactions In Northeastern Minnesota, L. David Mech, John Fieberg, Shannon M. Barber-Meyer

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

Wolf (Canis lupus) and moose (Alces americanus) populations in northeastern Minnesota, USA, have fluctuated for decades and, based on helicopter counts, moose numbers declined to a new low from 2006 to about 2012. Other steep declines were found in 1991 and 1998 during periods when moose counts were done with fixed-wing aircraft; these declines also appeared to be real. Winter wolf numbers, monitored in part of the moose range, had been increasing since about 2002 to the highest population in decades in 2009. However, from 2009 to 2016, wolves decreased precipitously, and the moose- population decline leveled …


Resource Selection Of Free-Ranging Horses Influenced By Fire In Northern Canada, Sonja E. R. Leverkus, Samuel D. Fuhlendorf, Marten Geertsema, Brady W. Allred, Mark Gregory, Alexandre R. Bevington, David M. Engle, J. Derek Scasta Jan 2018

Resource Selection Of Free-Ranging Horses Influenced By Fire In Northern Canada, Sonja E. R. Leverkus, Samuel D. Fuhlendorf, Marten Geertsema, Brady W. Allred, Mark Gregory, Alexandre R. Bevington, David M. Engle, J. Derek Scasta

Human–Wildlife Interactions

Free-ranging or feral horses (Equus ferus caballus) were important to the livelihood of First Nations and indigenous communities in Canada. The early inhabitants of the boreal region of British Columbia (BC) capitalized on naturally occurring wildfires and anthropogenic burning to provide forage for free-ranging horses and manage habitat for wildlife. This form of pyric herbivory, or grazing driven by fi re via the attraction to the palatable vegetation in recently burned areas, is an evolutionary disturbance process that occurs globally. However, its application to manage forage availability for free-ranging horses has not been studied in northern Canada. Across Canada, there …


Strike Hazard Posed By Columbids To Military Aircraft, Melanie R. Colón, Ashley M. Long Jan 2018

Strike Hazard Posed By Columbids To Military Aircraft, Melanie R. Colón, Ashley M. Long

Human–Wildlife Interactions

Wildlife-aircraft strikes threaten both human and animal safety and result in hundreds of millions of dollars per year in aircraft damage and lost flight hours. Large-bodied birds are especially hazardous to aircraft. However, given high-speed flight at low altitudes, military aircraft may be especially vulnerable to strikes and more susceptible to damage even when encountering small birds. We summarized all wildlife-aircraft strike records from Randolph Air Force Base (San Antonio, Texas) over a 25-year period and compared the number and cost of strikes across avian species and species groups. Because columbids (i.e., pigeons and doves) are among the most frequently …


Canid Vs. Canid: Insights Into Coyote-Dog Encounters From Social Media, Erin E. Boydston, Eric S. Abelson, Ari Kazanjian, Daniel T. Blumstein Jan 2018

Canid Vs. Canid: Insights Into Coyote-Dog Encounters From Social Media, Erin E. Boydston, Eric S. Abelson, Ari Kazanjian, Daniel T. Blumstein

Human–Wildlife Interactions

While the relationship between coyotes (Canis latrans) and house cats (Felis catus) may be characterized as one between predators and their prey, coyote interactions with domestic dogs (C. lupus familiaris) appear to be more varied and may include behaviors associated with canid sociality. While encounters between coyotes and dogs are difficult to observe, we capitalized on publically available video recordings of coyote-dog encounters to observe canid behaviors and examined 35 video clips downloaded from YouTube during fall 2014. We identified coyote-dog interactions that were playful, agonistic, or predatory; those that we could not clearly …


Post-Release Activity And Habitat Selection Of Rehabilitated Black Bears, Patrick J. Myers, Julie K. Young Jan 2018

Post-Release Activity And Habitat Selection Of Rehabilitated Black Bears, Patrick J. Myers, Julie K. Young

Human–Wildlife Interactions

Despite the long history of wildlife rehabilitation and the abundance of empirical knowledge of the behavior and resource selection of wildlife species, rarely does research bridge these disciplines. Such investigations could be of value to wildlife managers and rehabilitators by revealing the suitability of the habitat at selected release sites, the wild activities, behavior, and fitness of the captive-reared individuals, and ultimately the efficacy of the rehabilitation process. Rehabilitated carnivores warrant specific attention, given that they are wide-ranging and may behave in ways that threaten human safety or interests. We investigated the behavior of orphan, rehabilitated black bear cubs ( …


The Ethosophy Of The Grizzly Man: Timothy Treadwell's Three Ethologies, Blake L. Ginsburg Jan 2018

The Ethosophy Of The Grizzly Man: Timothy Treadwell's Three Ethologies, Blake L. Ginsburg

Graduate Student Theses, Dissertations, & Professional Papers

This paper explores the ethical appropriateness and significance of Timothy Treadwell’s life among the bears and foxes of Alaska’s Katmai National Park and Preserve. In an attempt to reveal the formative and transformative aspects of Treadwell’s project, I rely upon an ethological framework developed by Matthew Calarco that moves beyond the narrow conception of ethology as a scientific practice aimed at systematic and rigorous documentation of the quantifiable aspects of animal behavior. While many people might be hesitant to conceive of Treadwell’s project as an ethological one, I hope to illuminate the ways in which his life among bears and …


Life On The Edge: Risk Of Predation Drives Selection Of Habitat And Survival Of Neonates In Endangered Sierra Nevada Bighorn Sheep, Shannon Forshee Jan 2018

Life On The Edge: Risk Of Predation Drives Selection Of Habitat And Survival Of Neonates In Endangered Sierra Nevada Bighorn Sheep, Shannon Forshee

Graduate Student Theses, Dissertations, & Professional Papers

Long-term viability of endangered populations requires development of effective management strategies that target the population vital rate with the highest potential to influence population trajectories. When adult survival is high and stable, juvenile recruitment is the vital rate with the greatest potential to improve population trajectories. For my thesis I examined how lactating Sierra Nevada Bighorn sheep (Ovis Canadensis sierra) balance forage and predation risk during the neonatal period. I first identified resource selection strategies employed by lactating females to promote survival of neonates and then determined the primary factors affecting survival of neonates. I found lactating females selected for …


Seasonal Home Range Variation And Spatial Ecology Of Peregrine Falcons (Falco Peregrinus) In Coastal Humboldt County, Ca, Elizabeth-Noelle F. Morata Jan 2018

Seasonal Home Range Variation And Spatial Ecology Of Peregrine Falcons (Falco Peregrinus) In Coastal Humboldt County, Ca, Elizabeth-Noelle F. Morata

Cal Poly Humboldt theses and projects

Peregrine falcons (Falco peregrinus) are renowned for their migratory habits, with ‘peregrinus’ often translated as ‘wanderer’ or ‘pilgrim’. However, their migratory habits may differ by population and some peregrine may falcons forgo migration when climate and resources remain stable. To examine peregrine falcon home range and space use, I fitted GPS-satellite transmitters to nine breeding adults in coastal northern California, an area with a mild climate and abundant waterbird populations. I used kernel density estimates and time-local convex hulls to examine seasonal home ranges and within-home range habitat use. All nine peregrine falcons remained resident in …


Ecological Implications Of Foraging And Life-History In Three Cold-Adapted Species, Andrew Von Duyke Jan 2018

Ecological Implications Of Foraging And Life-History In Three Cold-Adapted Species, Andrew Von Duyke

Dissertations, Master's Theses and Master's Reports

This research investigates the ecology of: ringed seals (Pusa hispida), moose (Alces alces), and bowhead whales (Balaena mysticetus). Each of these species draws upon specialized strategies to meet the physical demands of life in their extreme environments. However, they are currently experiencing unprecedented changes in their habitats. This work adds to what is known about the behavior, physiology, and population dynamics of cold-adapted species—providing insights of value for an improved understanding of foraging and life-history theory, and informing conservation and ecosystem monitoring efforts. Chapter 1 provides a brief introduction to the scope of work …


The Effects Of The Red Tide Producing Dinoflagellate, Karenia Brevis, And Associated Brevetoxins On Viability And Sublethal Stress Responses In Scleractinian Coral: A Potential Regional Stressor To Coral Reefs, David A. Reynolds Jan 2018

The Effects Of The Red Tide Producing Dinoflagellate, Karenia Brevis, And Associated Brevetoxins On Viability And Sublethal Stress Responses In Scleractinian Coral: A Potential Regional Stressor To Coral Reefs, David A. Reynolds

UNF Graduate Theses and Dissertations

Coral cover is in decline on a global scale, with increased mortality events being attributed to a number of global and regional stressors. While the impacts of global stressors (e.g. sea surface temperature rise, ocean acidification) are well documented, there is growing interest in identifying and understanding the impacts of regional stressors. The reason for this change in focus is that regional stressors can often work in combination, sometimes synergistically, with global stressors and that stressors on a regional scale tend to be more easily mitigated by management practices. One regional stressor that impacts a myriad of marine organisms in …


American Black Bear Den-Site Selection And Characteristics In An Urban Environment, Toryn L. J. Schafer, Stewart W. Breck, Sharon Baruch-Mordo, David L. Lewis, Kenneth R. Wilson, Julie S. Mao, Thomas L. Day Jan 2018

American Black Bear Den-Site Selection And Characteristics In An Urban Environment, Toryn L. J. Schafer, Stewart W. Breck, Sharon Baruch-Mordo, David L. Lewis, Kenneth R. Wilson, Julie S. Mao, Thomas L. Day

United States Department of Agriculture Wildlife Services: Staff Publications

Selection of den sites is a crucial aspect of American black bear (Ursus americanus) life history. High-quality dens provide thermal insulation, protection from disturbance, suitable environment for parturition and cub development, and proximity to available forage upon emergence. Black bears are increasingly coexisting with people in human-dominated landscapes; however, little is known about whether urban environments influence characteristics of dens and den site selection. Our objective was to determine the effect of housing density (a proxy for human activity and availability of anthropogenic resources) on selection of den sites in years of good and poor natural forage.We additionally …


Large Birds Of Prey, Policies That Alter Food Availability And Air Traffic: A Risky Mix For Human Safety, Rubén Moreno-Opo, Antoni Margalida Dec 2017

Large Birds Of Prey, Policies That Alter Food Availability And Air Traffic: A Risky Mix For Human Safety, Rubén Moreno-Opo, Antoni Margalida

Human–Wildlife Interactions

Raptors are considered to pose one of the greatest aviation bird strike risk. We investigated raptor bird strikes reported at the largest Spanish airport (Adolfo Suárez Madrid Barajas; AS-MB) from 2009 to 2016 to determine the factors contributing to the increased incidences and develop recommendations to mitigate the risks. We hypothesized that increased raptor bird strikes resulted from changes in foraging and dispersal patterns of Iberian Peninsula vultures (Aegypius spp. and Gyps spp.) after 2004-2005. We used information on raptor bird strikes obtained from official databases and published studies, reported incidences of raptor bird strikes and their characteristics (i.e., …


Science And Sentiment: Affecting Change In Environmental Awareness, Attitudes, And Actions Through The Daily Nature Project, Elizabeth D. Haynes Poronsky Dec 2017

Science And Sentiment: Affecting Change In Environmental Awareness, Attitudes, And Actions Through The Daily Nature Project, Elizabeth D. Haynes Poronsky

The Transdisciplinary STEAM+ Journal

Knowledge about what motivates pro-environmental behavior is important to organizations that seek to encourage environmental stewardship. Research suggests that targeting emotions and beliefs about nature can be more effective in changing environmental actions than increasing knowledge. Daily Nature, a site on the social media platform Facebook, features a daily nature photograph, a quote from a notable historical person and a related lyrical written passage. The popularity of this site lends credence to the appeal of interdisciplinary formats, and underscores the benefits of encouraging emotional and aesthetic ties to nature.


Seasonal Resource Selection And Habitat Treatment Use By A Fringe Population Of Greater Sage-Grouse, Rhett Boswell Dec 2017

Seasonal Resource Selection And Habitat Treatment Use By A Fringe Population Of Greater Sage-Grouse, Rhett Boswell

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Movement and habitat selection by Greater Sage-grouse (Centrocercus uropasianus) is of great interest to wildlife managers tasked with applying conservation measures for this iconic western species. Current technology has created small and lightweight GPS (Global Positioning Systems) transmitters that can be attached to sage-grouse. Using GIS software and statistical programs such as Program R, land managers can analyze GPS location data to assess how sage-grouse are geospatially interacting with their habitats. Within the Panguitch Sage-Grouse Management Area (SGMA) thousands of acres of land have been restored or manipulated to enhance sage-grouse habitat; this usually involves removal of pinyon pine …


Effects Of Trophic Relationships On Oyster Reef Restoration Success In The Mississippi Sound, Virginia Robin Fleer Dec 2017

Effects Of Trophic Relationships On Oyster Reef Restoration Success In The Mississippi Sound, Virginia Robin Fleer

Dissertations

Natural and anthropogenic changes resulting from altered hydrology, hurricanes, variable precipitation, and the BP oil spill have all taken their toll on oyster reefs in Mississippi. In response, oyster reef restoration efforts are currently underway within the Northern Gulf of Mexico. In order to understand why these efforts succeed or fail, it is crucial to consider predator-prey relationships within the context of the trophic dynamics of oyster reefs. Thus, for this dissertation study I integrated a multidisciplinary approach to understanding key trophic interactions affecting oyster recruitment, growth and survival, comprising field sampling, manipulative lab experiments, and individual-based modeling. Spat settlement …


Effectiveness Of Chain Link Turtle Fence And Culverts In Reducing Turtle Mortality And Providing Connectivity Along U.S. Hwy 83, Valentine National Wildlife Refuge, Nebraska, Usa, Marcel P. Huijser, Kari E. Gunson, Elizabeth R. Fairbank Dec 2017

Effectiveness Of Chain Link Turtle Fence And Culverts In Reducing Turtle Mortality And Providing Connectivity Along U.S. Hwy 83, Valentine National Wildlife Refuge, Nebraska, Usa, Marcel P. Huijser, Kari E. Gunson, Elizabeth R. Fairbank

Nebraska Department of Transportation: Research Reports

We evaluated the effectiveness of existing turtle fences through collecting and analyzing turtle mortality data along U.S. Hwy 83, in and around Valentine National Wildlife Refuge, Nebraska, USA. We also investigated the level of connectivity for turtles provided through the culverts that were originally designed to pass water through a capture-mark-recapture experiment. While fenced valley sections had 33.1% fewer turtle observations than unfenced valley sections, the difference was not significant. However, we think that the effectiveness of the fence can be improved through fence repairs, other modifications of the fences, vegetation maintenance, and extending the length of the fences. Four …


Understanding And Finding Solutions To The Problem Of Sedimentation In The National Wildlife Refuge System, Max Post Van Der Burg, Karen E. Jenni, Timothy L. Nieman, Josh D. Eash, Gregory A. Knutsen Dec 2017

Understanding And Finding Solutions To The Problem Of Sedimentation In The National Wildlife Refuge System, Max Post Van Der Burg, Karen E. Jenni, Timothy L. Nieman, Josh D. Eash, Gregory A. Knutsen

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

The National Wildlife Refuge System (Refuge System) is a collection of public lands maintained by the U.S. Fish and Wildlife Service for migratory birds and other wildlife. Wetlands on individual National Wildlife Refuges (Refuges) may be at risk of increased sedimentation because of land use and water management practices. Increased sedimentation can reduce wetland habitat quality by altering hydrologic function, degrading water quality, and inhibiting growth of vegetation and invertebrates. On Refuges negatively affected by increased sedimentation, managers have to address complex questions about how to best remediate and mitigate the negative effects. The best way to account for these …


A Study Of The Urban Red Fox (Vulpes Vulpes) Population In Baton Rouge, Louisiana Using Social Media, Ahsennur Soysal Nov 2017

A Study Of The Urban Red Fox (Vulpes Vulpes) Population In Baton Rouge, Louisiana Using Social Media, Ahsennur Soysal

LSU Master's Theses

Foxes are timid yet resourceful animals that are integrated into many urban environments. Because they are elusive, collecting information about the number of urban foxes, their diet and spatial distribution, their interactions with the ecological community in their urban habitat, as well as residents’ response to them, is difficult. Involving stakeholders to participate in the data collection on wildlife via citizen science on social media is one way to overcome this complication, while simultaneously engaging residents in the ecology happening around them. Therefore, we used social media as the platform to engage the public to document and map the foxes …


The Utility Of Bioenergetics Modelling In Quantifying Predation Rates Of Marine Apex Predators: Ecological And Fisheries Implications, A. Barnett, M. Braccini, C. L. Dudgeon, N. L. Payne, K. G. Abrantes, M. Sheaves, E. P. Snelling Oct 2017

The Utility Of Bioenergetics Modelling In Quantifying Predation Rates Of Marine Apex Predators: Ecological And Fisheries Implications, A. Barnett, M. Braccini, C. L. Dudgeon, N. L. Payne, K. G. Abrantes, M. Sheaves, E. P. Snelling

Fisheries Research Articles

Predators play a crucial role in the structure and function of ecosystems. However, the magnitude of this role is often unclear, particularly for large marine predators, as predation rates are difficult to measure directly. If relevant biotic and abiotic parameters can be obtained, then bioenergetics modelling offers an alternative approach to estimating predation rates, and can provide new insights into ecological processes. We integrate demographic and ecological data for a marine apex predator, the broadnose sevengill shark Notorynchus cepedianus, with energetics data from the literature, to construct a bioenergetics model to quantify predation rates on key fisheries species in …


The North American Quails, Partridges, And Pheasants, Paul A. Johnsgard Oct 2017

The North American Quails, Partridges, And Pheasants, Paul A. Johnsgard

Zea E-Books Collection

This book documents the biology of six species of New World quails that are native to North America north of Mexico (mountain, scaled, Gambel’s, California, and Montezuma quails, and the northern bobwhite), three introduced Old World partridges (chukar, Himalayan snowcock, and gray partridge), and the introduced common (ring-necked) pheasant. Collectively, quails, partridges, and pheasants range throughout all of the continental United States and the Canadian provinces. Two of the species, the northern bobwhite and ring-necked pheasant, are the most economically important of all North American upland game birds. All of the species are hunted extensively for sport and are highly …


The Behavior Response Of Antlion Larvae To Alternating Magnetic Fields, Lindsey Wagner, Caleb L. Adams Oct 2017

The Behavior Response Of Antlion Larvae To Alternating Magnetic Fields, Lindsey Wagner, Caleb L. Adams

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.


Modeling Evolutionary Games Between Predators And Social Prey, Bill Mitchell Oct 2017

Modeling Evolutionary Games Between Predators And Social Prey, Bill Mitchell

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.


Investigation Of Seed And Seedling Predation And Natural History Of Bushveld Savanna Rodents, Christopher Banotai Oct 2017

Investigation Of Seed And Seedling Predation And Natural History Of Bushveld Savanna Rodents, Christopher Banotai

Masters Theses & Specialist Projects

There is currently a decline in large, old trees within many ecosystems where they play important ecological and economic roles. One ecosystem suffering from this decline is the bushveld savanna of South Africa. One particularly important species in decline is the ecologically, economically, and culturally significant marula tree (Sclerocarya birrea subsp. caffra). This species’ decline is characterized by a steep drop in recruitment of seedlings into the population. Rodents are known to influence plant communities across many ecosystems through herbivory of adult plants as well as predation of seeds and seedlings. This research provides a record of rodent species present …


Field Evidence Challenges The Often-Presumed Relationship Between Early Male Maturation And Female-Biased Sexual Size Dimorphism, Marie Claire Chelini, Eileen Hebets Oct 2017

Field Evidence Challenges The Often-Presumed Relationship Between Early Male Maturation And Female-Biased Sexual Size Dimorphism, Marie Claire Chelini, Eileen Hebets

Eileen Hebets Publications

Female-biased sexual size dimorphism (SSD) is often considered an epiphenomenon of selection for the increased mating opportunities provided by early male maturation (i.e., protandry). Empirical evidence of the adaptive significance of protandry remains nonetheless fairly scarce. We use field data collected throughout the reproductive season of an SSD crab spider, Mecaphesa celer, to test two hypotheses: Protandry provides fitness benefits to males, leading to female-biased SSD, or protandry is an indirect consequence of selection for small male size/large female size. Using field-collected data, we modeled the probability of mating success for females and males according to their timing of …