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Full-Text Articles in Physical Sciences and Mathematics
Does Helping-At-The-Nest Help? The Case Of The Acorn Woodpecker, Walter D. Koenig, Eric L. Walters, Sahas Barve
Does Helping-At-The-Nest Help? The Case Of The Acorn Woodpecker, Walter D. Koenig, Eric L. Walters, Sahas Barve
Biological Sciences Faculty Publications
Cooperative breeding groups often involve "helpers-at-the-nest"; indeed, such behavior typically defines this intriguing breeding system. In few cases, however, has it been demonstrated that feeding nestlings by helpers, rather than some other behavior associated with helpers' presence, leads to greater reproductive success. One prediction of the hypothesis that feeding behavior per se is responsible for the fitness benefits conferred by helpers is that there should be close congruence between the patterns of helping-at-the-nest and the fitness effects of helpers. Here we look for such a relationship in the cooperatively breeding acorn woodpecker (Melanerpes formicivorus) in order to begin …
Heritable Melanism And Parasitic Infection Both Result In Black-Spotted Mosquitofish, Lisa Horth, David Gauthier, Wolfgang Vogelbein
Heritable Melanism And Parasitic Infection Both Result In Black-Spotted Mosquitofish, Lisa Horth, David Gauthier, Wolfgang Vogelbein
Biological Sciences Faculty Publications
Male Gamhusia holhrooki (Eastern Mosquitofish) express a heritable pigmentation polymorphism approximate to 99% of males are silver, and only approximate to 1% have a melanic, black-spotted pattern. Sex-linkage, an autosomal modifier, and temperature control the expression of this heritable melanism. In many teleosts, melanin also accumulates around the site of parasitic invasion. We have identified black-spot disease in wild mosquitofish from their native habitat. Here, we demonstrate convergence upon the black-pigmented phenotype through two means: 1) heritable melanism, and 2) melanic spotting on the silver genotype that results from infection with immature encysted trematodes. Females are silver and express greater …
Effects Of Human Disturbances On The Behavior Of Wintering Ducks, Melissa L. Pease, Robert K. Rose, Mark J. Butler
Effects Of Human Disturbances On The Behavior Of Wintering Ducks, Melissa L. Pease, Robert K. Rose, Mark J. Butler
Biological Sciences Faculty Publications
Human activity causes wintering waterfowl to expend energy to avoid humans at a time in their annual cycle when energy conservation is important to survival, migration, and breeding reserves. Understanding the effects of recreational activities on waterfowl is important to managing natural resource areas where migratory birds depend on wetland habitat for resting and feeding. We investigated responses of 7 species of dabbling ducks to 5 different experimental human activities, (a pedestrian, a bicyclist, a truck traveling at 2 different speeds, and an electric passenger tram). Responses of ducks depended on type of disturbance, species, and distance from disturbances. Most …
Development And Evaluation Of Tracer Particles For Use In Microzooplankton Herbivory Studies, Mary Putt
Development And Evaluation Of Tracer Particles For Use In Microzooplankton Herbivory Studies, Mary Putt
OES Faculty Publications
Two methods of preparing algae for use as tracer particles in single species measurements of microzooplankton herbivory were evaluated. Algae were either heat-killed and labelled with 5-(4,6-dichlorotriazin-2-yl amino fluorescein) (DTAF) (Rublee & Gallegos 1989; Mar, Ecol. Prog. Ser. 51: 221-227) or stained with hydroethidine (HYD). Both DTAF and HYD-stained algae were readily visible within the digestive vacuoles of most microzooplankton collected in estuarine and coastal waters of Massachusetts (USA) and preserved with Lugol's iodine. However, DTAF was ineffective at staining several chromophytic algae and the heat-kill process reduced cell volume by ≥ 50% in several of the algae which were …