Temporal and Spatial Patterns of Avifauna on Wetlands in the Vicinity of Bush Field Airport, Augusta, Georgia, USA

Responding to a U.S. Federal court order to improve discharged wastewater quality, Augusta, Georgia initiated development of artificial wetlands in 1997 to treat effluents. Because of the proximity to Augusta Regional Airport at Bush Field, the U.S. Federal Aviation Administration expressed concern for potential increased hazard to aircraft posed by birds attracted to these wetlands. We commenced weekly low-level aerial surveys of habitats in the area beginning January, 1998. Over a one-year period, 49 surveys identified approximately 42,000 birds representing 52 species, including protected Wood Storks and Bald Eagles, using wetlands within 8 km of the airport. More birds were observed during the mid-winter and fall/spring migratory seasons (1,048 birds/survey; October - April) than during the breeding/post-breeding seasons (394 birds/survey; May - September). In winter, waterfowl dominated the avian assemblage (65% of all birds). During summer, wading birds were most abundant (56% of all birds). Habitat changes within the artificial wetlands produced fish kills and exposed mudflats, resulting in increased use by wading birds and shorebirds. No aquatic birds were implicated in 1998 bird strikes, and most birds involved could safely be placed within songbird categories. Airport incident reports further implicated songbirds. These findings suggested that efforts to decrease numbers of songbirds on the airport property must be included in the development of a wildlife hazard management plan. Seasonal differences in site use among species groups should also be considered in any such plan. Other wetlands within 8 km of the airport supported as many or more birds than the artificial wetlands. With proper management of the artificial wetlands, it should be possible to successfully displace waterfowl and wading birds to other wetlands further from the airport

HIV infection and sexual risk among men who have sex with men and women (MSMW): A systematic review and meta-analysis

Objectives: To estimate the number of men who have sex with men and women who are HIV-positive in the United States, and to compare HIV prevalence rates between men who have sex with men and women, men who have sex with men only, and men who have sex with women exclusively. Methods: Following PRISMA guidelines, we conducted a systematic review and meta-analysis of reports referencing HIV prevalence and men who have sex with men and women. We searched PubMed and Ovid PsycINFO for peer-reviewed, U.S.-based articles reporting on HIV prevalence among men who have sex with men and women. We conducted event rate, effect size, moderation and sensitivity analyses. Results: We estimate that 1.0% of U.S. males are bisexually-behaving, and that 121,800 bisexually-behaving men are HIV-positive. Men who have sex with men and women are less than half as likely to be HIV-positive as men who have sex with men only (16.9% vs. 33.3%; OR = 0.41, 95% CI: 0.31, 0.54), but more than five times as likely to be HIV-positive as men who have sex with women exclusively (18.3% vs. 3.5%; OR = 5.71, 95% CI: 3.47, 9.39). They are less likely to engage in unprotected receptive anal intercourse than men who have sex with men only (15.9% vs. 35.0%; OR = 0.36, 95% CI: 0.28, 0.46). Men who have sex with men and women in samples with high racial/ethnic minority proportions had significantly higher HIV prevalence than their counterparts in low racial/ethnic minority samples. Conclusions: This represents the first meta-analysis of HIV prevalence in the U.S. between men who have sex with men and women and men who have sex with men only. Data collection, research, and HIV prevention and care delivery specifically tailored to men who have sex with men and women are necessary to better quantify and ameliorate this population's HIV burden. © 2014 Friedman et al

Data from: Laying sequence interacts with incubation temperature to influence rate of embryonic development and hatching synchrony in a precocial bird

Incubation starts during egg laying for many bird species and causes developmental asynchrony within clutches. Faster development of late-laid eggs can help reduce developmental differences and synchronize hatching, which is important for precocial species whose young must leave the nest soon after hatching. In this study, we examined the effect of egg laying sequence on length of the incubation period in Wood Ducks (Aix sponsa). Because incubation temperature strongly influences embryonic development rates, we tested the interactive effects of laying sequence and incubation temperature on the ability of late-laid eggs to accelerate development and synchronize hatching. We also examined the potential cost of faster development on duckling body condition. Fresh eggs were collected and incubated at three biologically relevant temperatures (Low: 34.9°C, Medium: 35.8°C, and High: 37.6°C), and egg laying sequences from 1 to 12 were used. Length of the incubation period declined linearly as laying sequence advanced, but the relationship was strongest at medium temperatures followed by low temperatures and high temperatures. There was little support for including fresh egg mass in models of incubation period. Estimated differences in length of the incubation period between eggs 1 and 12 were 2.7 d, 1.2 d, and 0.7 d at medium, low and high temperatures, respectively. Only at intermediate incubation temperatures did development rates of late-laid eggs increase sufficiently to completely compensate for natural levels of developmental asynchrony that have been reported in Wood Duck clutches at the start of full incubation. Body condition of ducklings was strongly affected by fresh egg mass and incubation temperature but declined only slightly as laying sequence progressed. Our findings show that laying sequence and incubation temperature play important roles in helping to shape embryo development and hatching synchrony in a precocial bird

Frequency and Timing of Second Broods in Wood Ducks

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Laying sequence interacts with incubation temperature to influence rate of embryonic development and hatching synchrony in a precocial bird

<div><p>Incubation starts during egg laying for many bird species and causes developmental asynchrony within clutches. Faster development of late-laid eggs can help reduce developmental differences and synchronize hatching, which is important for precocial species whose young must leave the nest soon after hatching. In this study, we examined the effect of egg laying sequence on length of the incubation period in Wood Ducks (<b><i>Aix sponsa</i></b>). Because incubation temperature strongly influences embryonic development rates, we tested the interactive effects of laying sequence and incubation temperature on the ability of late-laid eggs to accelerate development and synchronize hatching. We also examined the potential cost of faster development on duckling body condition. Fresh eggs were collected and incubated at three biologically relevant temperatures (Low: 34.9°C, Medium: 35.8°C, and High: 37.6°C), and egg laying sequences from 1 to 12 were used. Length of the incubation period declined linearly as laying sequence advanced, but the relationship was strongest at medium temperatures followed by low temperatures and high temperatures. There was little support for including fresh egg mass in models of incubation period. Estimated differences in length of the incubation period between eggs 1 and 12 were 2.7 d, 1.2 d, and 0.7 d at medium, low and high temperatures, respectively. Only at intermediate incubation temperatures did development rates of late-laid eggs increase sufficiently to completely compensate for natural levels of developmental asynchrony that have been reported in Wood Duck clutches at the start of full incubation. Body condition of ducklings was strongly affected by fresh egg mass and incubation temperature but declined only slightly as laying sequence progressed. Our findings show that laying sequence and incubation temperature play important roles in helping to shape embryo development and hatching synchrony in a precocial bird.</p></div

Temporal and Spatial Patterns of Avifauna on Wetlands in the Vicinity of Bush Field Airport, Augusta, Georgia, USA

Responding to a U.S. Federal court order to improve discharged wastewater quality, Augusta, Georgia initiated development of artificial wetlands in 1997 to treat effluents. Because of the proximity to Augusta Regional Airport at Bush Field, the U.S. Federal Aviation Administration expressed concern for potential increased hazard to aircraft posed by birds attracted to these wetlands. We commenced weekly low-level aerial surveys of habitats in the area beginning January, 1998. Over a one-year period, 49 surveys identified approximately 42,000 birds representing 52 species, including protected Wood Storks and Bald Eagles, using wetlands within 8 km of the airport. More birds were observed during the mid-winter and fall/spring migratory seasons (1,048 birds/survey; October - April) than during the breeding/post-breeding seasons (394 birds/survey; May - September). In winter, waterfowl dominated the avian assemblage (65% of all birds). During summer, wading birds were most abundant (56% of all birds). Habitat changes within the artificial wetlands produced fish kills and exposed mudflats, resulting in increased use by wading birds and shorebirds. No aquatic birds were implicated in 1998 bird strikes, and most birds involved could safely be placed within songbird categories. Airport incident reports further implicated songbirds. These findings suggested that efforts to decrease numbers of songbirds on the airport property must be included in the development of a wildlife hazard management plan. Seasonal differences in site use among species groups should also be considered in any such plan. Other wetlands within 8 km of the airport supported as many or more birds than the artificial wetlands. With proper management of the artificial wetlands, it should be possible to successfully displace waterfowl and wading birds to other wetlands further from the airport

Wastewater Treatment Wetlands: Potential Hazardous Wildlife Attractants for Airports

Wetlands constructed for the treatment of urban wastewater effluent have gained world-wide popularity in recent decades. Placement of such wetlands near airports however, is strongly discouraged by the U.S. Federal Aviation Administration, other national airport authorities, and the International Bird Strike Committee because they attract birds that may increase strike risks for aircraft. Despite recognition of this and other wildlife hazards to aircraft and efforts implemented to limit such land-use activities near airports, validated methods are still urgently needed to mitigate wildlife hazards on or near air-ports because bird populations and bird-aircraft strikes in the U.S. and elsewhere around the world persistently trend upward. The city of Augusta, Georgia USA designed and developed 144 ha of wastewater treatment wetlands on land adjacent to its Regional Airport at Bush Field during 1997–2002. In December 2001, we began temporal and spatial monitoring of bird activities in this area, recording species, their numbers, and flight characteristics. Within 2 years of completion, the wetlands, dominated by giant cut-grass (Zizaniopsis miliacea) and cattails (Typha spp.), served as a nighttime roost for millions of migratory blackbirds (family Icteridae) that crossed the airfield in massive flocks daily at sunrise and sunset during November–March. Beginning in December 2005, we investigated the efficacy of habitat alteration techniques to displace the blackbirds, including the use of airboats to mechanically crush wetland vegetation in portions of the treatment wetlands. The results of this method were highly significant, with far fewer blackbirds landing in crushed-vegetation areas than in uncrushed areas. Beginning with the fall of 2008, this vegetation-crushing technique was implemented annually for the entire wetland system; long-term post-crush bird monitoring indicated that blackbird roosting within the wetlands was almost non-existent and blackbird activity around the airport was reduced by about 2 orders of magnitude. The ability of the wetland vegetation to process wastewater effluent was not negatively affected by vegetation alteration. This work successfully demonstrated that with thoughtful wildlife hazard management, including the consideration of novel techniques, it may be possible to mitigate large-scale undesirable wildlife attraction associated with certain land-use activities. Importantly, this success was accomplished through non-lethal means, using a relatively simplistic habitat altering technique. Throughout the succession of these events, careful monitoring of bird-aircraft strikes, bird numbers and their movements, and an unbiased evaluation of bird mitigation efforts formed the foundation of the success that was achieved

Wood Duck laying sequence

Comma delimited file used to examine effects of incubation temperature and egg laying sequence of wood ducks (Aix sponsa) on length of the incubation period and body condition of day-old ducklings

Predicted relationships between egg laying sequence and incubation period.

<p>Parameter estimates are from the top ranked model (<i>w</i>_<i>i</i> = 0.76; <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0191832#pone.0191832.t002" target="_blank">Table 2</a>) and show interactive effects of egg laying sequence and incubation temperature (low, medium and high) on length of the incubation period in Wood Ducks.</p

Laying sequence and parasitized nests

Comma delimited file used to test whether daily parasitism of nests across the laying sequence differed between incubation temperature treatments