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Full-Text Articles in Life Sciences
Intraspecific Intrusion At Bald Eagle Nests, Courtney Turrin, B. D. Watts
Intraspecific Intrusion At Bald Eagle Nests, Courtney Turrin, B. D. Watts
Arts & Sciences Articles
Competition for nesting territory has been shown to act as a density-dependent feedback mechanism influencing population growth rate. However, little is known about the nature of territorial interactions between established breeders and floaters. We examined territorial intrusion rates and associated behaviours at active Bald Eagle Haliaeetus leucocephalus nests in the lower Chesapeake Bay in 2012 and 2013. The average intrusion rate experienced at study nests during the reproductive period was 0.28 ± 0.32 intrusions/h. Variance in intrusion rate was high and there was no apparent predictive pattern to these events. Juvenile intrusions occurred closer to the nest than adult intrusions, …
Stormwater Runoff Drives Viral Community Composition Changes In Inland Freshwaters, Randolph Chambers
Stormwater Runoff Drives Viral Community Composition Changes In Inland Freshwaters, Randolph Chambers
Arts & Sciences Articles
Storm events impact freshwater microbial communities by transporting terrestrial viruses and other microbes to freshwater systems, and by potentially resuspending microbes from bottom sediments. The magnitude of these impacts on freshwater ecosystems is unknown and largely unexplored. Field studies carried out at two discrete sites in coastal Virginia (USA) were used to characterize the viral load carried by runoff and to test the hypothesis that terrestrial viruses introduced through stormwater runoff change the composition of freshwater microbial communities. Field data gathered from an agricultural watershed indicated that primary runoff can contain viral densities approximating those of receiving waters. Furthermore, viruses …
The Influence Of Recreational Crabbing Regulations On Diamondback Terrapin By-Catch, Randolph Chambers
The Influence Of Recreational Crabbing Regulations On Diamondback Terrapin By-Catch, Randolph Chambers
Arts & Sciences Articles
Malaclemys terrapin terrapin (Northern Diamondback Terrapin) is susceptible to drowning in commercial-style pots used for the Callinectes sapidus (Blue Crab) fishery. Regulations to reduce by-catch mortality vary by state. We compared three different regulatory strategies with respect to crab catch and their relative effectiveness at reducing terrapin by-catch. To mimic their possible use by recreational crabbers, we grouped and fished together ten unbaited crab pots with no by-catch reduction devices (BRDs), ten with large BRDs, and ten with small BRDs in a tidal creek in southeastern Virginia. Over 24 sampling days, the total legal crab catch (crabs ≥ 12.7 cm) …
Recovery Of Breeding Bald Eagles On Aberdeen Proving Ground, B. D. Watts
Recovery Of Breeding Bald Eagles On Aberdeen Proving Ground, B. D. Watts
Arts & Sciences Articles
We conducted annual aerial surveys (1991-2011) for breeding Bald Eagles (Haliaeetus leucocephalus) within Aberdeen Proving Ground (APG), a 350-km2 military installation located along the northwestern shoreline of the upper Chesapeake Bay in Maryland. The population increased exponentially from 1 pair in 1977 to 58 pairs in 2011 with an average doubling time of 5.8 years. This rate was higher than that documented for the broader Chesapeake Bay and is comparable to the highest reported throughout the species range. Annual population increase was highly variable and exhibited no indication of any systematic decline. A total of 646 chicks were produced from …