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Gary R. Hepp - One of the best experts on this subject based on the ideXlab platform.
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Sample sizes of Wood Duck nests and eggs and mean (± SE) incubation temperature and incubation period by temperature treatment.
2018Co-Authors: Gary R. Hepp, Robert A KennamerAbstract:Sample sizes of Wood Duck nests and eggs and mean (± SE) incubation temperature and incubation period by temperature treatment.
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Laying sequence interacts with incubation temperature to influence rate of embryonic development and hatching synchrony in a precocial bird
2018Co-Authors: Gary R. Hepp, Robert A KennamerAbstract: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.
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thermal challenge severity differentially influences wound healing in Wood Duck aix sponsa Ducklings
Journal of Experimental Zoology, 2013Co-Authors: Amanda W Carter, Gary R. Hepp, Sarah E Durant, William A HopkinsAbstract:Environmental conditions during early development can profoundly influence an individual's phenotype. Development requires simultaneous maturation and orchestration of multiple physiological systems creating the potential for interaction among key systems and requiring substantial resources. We investigated the influence of thermoregulation on immunocompetence in Wood Duck Ducklings (Aix sponsa). At both 1 and 2 days post hatch (dph) we evaluated Ducklings' abilities to thermoregulate during a thermal challenge at one of four temperatures (36 [thermoneutral controls], 20, 10, or 5°C). At 3 dph, Ducklings received a superficial wound, which was monitored until full recovery to quantify wound healing ability, an ecologically relevant, integrative measure of immune function. We demonstrated that Duckling body temperature decreased with increasing thermal challenge severity, thermoregulatory ability increased with age, and thermoregulation had temperature-dependent effects on the immune system. Specifically, a more severe thermal challenge (5°C) resulted in decreased immune performance when compared to a mild challenge (20°C). We conclude that early thermoregulatory experiences are influential in shaping immune responses early in development. Furthermore, our results emphasize that future studies of environmental stressors need to consider multiple physiological endpoints since interaction among systems can result in competing physiological demands. J. Exp. Zool. 319A: 422–429, 2013. © 2013 Wiley Periodicals, Inc.
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effects of nest reuse and onset of incubation on microbial growth and viability of Wood Duck eggs
The Condor, 2012Co-Authors: Johnathan G Walls, Gary R. Hepp, Lori G EckhardtAbstract:Abstract. In many birds, egg viability declines the longer that eggs remain unincubated (i.e., incubation delay), possibly because of increased levels of microbial infection. Reuse of nests is common in cavity-nesting species and may also increase exposure of eggs to microbes. Starting incubation before the clutch is complete may help protect early-laid eggs from microbial infection. In this study, we tested the effects of nest cleaning, length of incubation delay, and onset of night incubation on growth of microbes on Wood Duck (Aix sponsa) eggshells and examined the effect of microbial infection on hatching success. We used nest boxes that had been cleaned or not cleaned of previous nesting materials and sampled microbes on eggshells during early and mid egg laying and after the start of night incubation. We detected levels of eggshell microbes (101 colony forming units [CFU] egg-1) lower than at more tropical locations (103–4 CFU egg-1). Levels of heterotrophic bacteria were 2.2 times greater in unclea...
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incubation temperature affects multiple measures of immunocompetence in young Wood Ducks aix sponsa
Biology Letters, 2012Co-Authors: Sarah E Durant, William A Hopkins, Dana M Hawley, Gary R. HeppAbstract:Parental effects play a vital role in shaping offspring phenotype. In birds, incubation behaviour is a critical parental effect because it influences the early developmental environment and can therefore have lifelong consequences for offspring phenotype. Recent studies that manipulated incubation temperature found effects on hatchling body composition, condition and growth, suggesting that incubation temperature could also affect energetically costly physiological processes of young birds that are important to survival (e.g. immune responses). We artificially incubated Wood Duck (Aix sponsa) eggs at three biologically relevant temperatures. Following incubation, we used two immunoassays to measure acquired immune responses of Ducklings. Ducklings incubated at the lowest temperature had reduced growth, body condition and responses to both of our immune challenges, compared with those from the higher temperatures. Our results show that incubation temperatures can be an important driver of phenotypic variation in avian populations.
Robert A Kennamer - One of the best experts on this subject based on the ideXlab platform.
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Laying sequence interacts with incubation temperature to influence rate of embryonic development and hatching synchrony in a precocial bird
2018Co-Authors: Gary R. Hepp, Robert A KennamerAbstract: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.
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Sample sizes of Wood Duck nests and eggs and mean (± SE) incubation temperature and incubation period by temperature treatment.
2018Co-Authors: Gary R. Hepp, Robert A KennamerAbstract:Sample sizes of Wood Duck nests and eggs and mean (± SE) incubation temperature and incubation period by temperature treatment.
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relating climatological patterns to wetland conditions and Wood Duck production in the southeastern atlantic coastal plain
Wildlife Society Bulletin, 2016Co-Authors: Robert A KennamerAbstract:Efforts to index annual population size and recruitment of the Wood Duck (Aix sponsa) on a geographic scale sufficiently large to be useful in managing this species have met with mixed results. A general relationship between climatic factors and Wood Duck produc- tion has been the most economical and promising approach, particularly in the South- east, though further refinement or understanding of factors mediating the relationship has been lacking. Development of climate-based models that predict wetland hydrologic conditions during the Wood Duck breeding season can be a useful step to index recruit- ment and may provide useful insights into population dynamics. In this study, I illustrate the concept's potential by developing a robust deterministic model of wetland water con- ditions on the 78,000-ha Savannah River Site (SRS) in west-central South Carolina over a 13-year period (1984-1996). During 6 years (1982-1987) when more than 90% of all hatched Ducklings were marked before leaving nest boxes on the SRS, production of female Ducklings was related positively to estimated female recruitment into the popula- tion the following year (combined breeding and nonbreeding yearling population seg- ments; rs=0.90, P=0.015), indicating that Duckling production was a reasonable proxy for recruitment. The return of females initially marked as Ducklings suggested that deferred yearling breeding was highest in dry years that were preceded by wetter years, thereby contributing to lower productivity in such years. Annual wetland condition indices were related to 15 years of Duckling production from SRS nest boxes. Productiv- ity of Wood Ducks was positively associated with wetland hydrologic conditions. In wet years, an average of 9.8?0.7 (SE) Ducklings was produced by each female in the breed- ing population, but only 8.6?0.5 (SE) Ducklings/female were produced in dry years. Greater productivity in wet years was attributed in part to longer breeding seasons, which allowed more females in the population to produce second broods, and to reduced pre- dation rates. Additional insights gained through application of the method are discussed.
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maternal effects in Wood Ducks incubation temperature influences incubation period and neonate phenotype
Functional Ecology, 2006Co-Authors: Gary R. Hepp, Robert A Kennamer, Maribeth H JohnsonAbstract:Summary 1Maternal effects often explain a significant amount of variation in offspring phenotype, and can be important in the evolution of life histories. Incubation of eggs is an important maternal effect, and optimal growth and development of avian embryos takes place within a narrow range of incubation temperatures, but the effect of incubation microclimate on neonate phenotype remains relatively unexplored in birds. 2In this study of Wood Ducks (Aix sponsa Linnaeus) we examined effects of incubation temperature on the length of incubation period and neonate quality. We monitored nest temperatures and incubation periods of naturally incubated Wood Duck nests and found a strong inverse relationship between incubation period and average nest temperature. 3Next, we collected three unincubated eggs from each of 48 nests, and randomly assigned eggs from each nest to one of three incubation temperatures (34·6, 36·0 and 37·4 °C). Experimental incubation temperatures overlapped average nest temperatures of naturally incubated Wood Duck nests. 4Hatching success varied with incubation temperature and was lowest for eggs incubated at the lowest temperature. Incubation period of experimental eggs decreased with increasing temperature but was not affected by fresh egg mass. 5Wood Duck embryos catabolized an estimated 34–38% of egg lipids and 25–33% of egg protein during incubation. Percentage change of lipids increased with decreasing incubation temperature, but not significantly. Embryos incubated at lower temperatures used a greater percentage of protein than embryos incubated at higher temperatures. 6In analyses using fresh egg mass as the covariate, we found that wet and dry mass of Ducklings increased with increasing incubation temperature. Decreases in lipid content of Wood Duck neonates with decreasing incubation temperature were not significant, but eggs incubated at low temperatures produced Ducklings that had reduced protein mass and that were structurally larger than Ducklings from eggs incubated at high temperatures. 7Our study illustrates the importance of incubation temperature on the development of Wood Duck embryos. Decisions made by incubating parents that influence egg temperature can modify incubation period and offspring phenotype. Investigations of incubation as a reproductive cost should consider how parental decisions influence both parents and offspring.
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mercury patterns in Wood Duck eggs from a contaminated reservoir in south carolina usa
Environmental Toxicology and Chemistry, 2005Co-Authors: Robert A Kennamer, Jason Stout, Brian P Jackson, Sheila V Colwell, Lehr I Brisbin, Joanna BurgerAbstract:Mercury contamination of wildlife populations has been documented widely in recent years as biomonitoring has become an important tool for assessing environmental contamination. Avian eggs provide an ideal assay material for Hg biomonitoring, particularly when the collection of eggs is simplified by using cavity-nesting species that nest in easily monitored nest boxes. However, studies are needed that address the dynamics of how Hg is distributed within eggs, and how Hg is deposited naturally within clutches laid by a single female and among clutches laid by different females occupying the same contaminated environment. We collected 138 eggs from 13 complete clutches of box-nesting Wood Ducks (Aix sponsa) during 1991 and 1992 at a contaminated reservoir of the U.S. Department of Energy's Savannah River Site in South Carolina, USA. Total Hg residues in egg components and clutches were determined, partitioning of Hg among egg components was examined, and effects of egg-laying sequence on egg component Hg levels were determined. Mean albumen Hg was 0.22 ppm wet mass, mean yolk Hg was 0.04 ppm, and mean shell Hg was 0.03 ppm. On average, 86.1% of total egg Hg was concentrated in the albumen, 11.2% in the yolk, and 2.7% in the shell. Mercury concentrations in all egg components varied significantly among clutches and between successive clutches laid by the same female in the same year. Laying sequence significantly affected Hg concentrations in the albumen and shell, but not in the yolk. Declines of albumen Hg due to laying sequence were more pronounced for clutches that contained higher average Hg levels. Our results suggest that collection of first-laid eggs may be preferable for assessing maximal Hg exposure to developing embryos, and that monitoring Hg levels through the use of empty eggshells following brood departure from nests may be valid only if the laying sequence is known.
Leopold Frederic - One of the best experts on this subject based on the ideXlab platform.
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Wood Duck nesting boxes
Avian Archives of Iowa Online, 2017Co-Authors: Leopold FredericAbstract:An article on how to build a Wood Duck nesting box compiled by Frederic Leopold, October 12, 1970. The article includes instructions on the types of materials required, the proper dimensions to use, where and how to hang a completed Wood Duck house, and how to track Wood Duck activity.
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Wood Duck nesting records volume two 1954 1966
Avian Archives of Iowa Online, 2017Co-Authors: Leopold FredericAbstract:Wood Duck nesting records covering the years 1954-1966 compiled by Frederic Leopold. The mostly handwritten volume contains Leopold's detailed notes on the nesting habits of Wood Ducks, including the following: nest site selection, egg laying, incubation, hatching, and departure from the nest. Also included in this volume are newspaper clippings, correspondence, Clemson Agricultural College Leaflet No. 20 on the Wood Duck written by Robert E. Ware, instructions on how to build a Wood Duck nesting box, and an article from National Wildlife titled "Of spring and an egg" written by Jean George.
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report to Wood Duck observers with attached mailing list september 13 1963
Avian Archives of Iowa Online, 2017Co-Authors: Leopold FredericAbstract:A report sent to Wood Duck observers with attached mailing list, September 13, 1963. The report compiles the data from the twenty people that reported their observations on 50 Wood Duck nesting boxes. Also included with the report is a copy of the original Wood Duck nesting boxes information sheet from January 17, 1963. This document is related to correspondence and Wood Duck study materials: https://avian.lib.iastate.edu/documents/3111/view , https://avian.lib.iastate.edu/documents/3112/view , and https://avian.lib.iastate.edu/documents/3114/view .
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documents regarding a Wood Duck study 1963
Avian Archives of Iowa Online, 2017Co-Authors: Leopold FredericAbstract:A brief letter and a questionnaire relating to a Wood Duck study done to gather information on nesting wild Wood Ducks, 1963. The letter describes the purpose of the study and asks for help in filling out the attached questionnaire. The questionnaire covers topics including: the date the Ducks were first seen, the date incubation started, the date of hatch, number of young Ducklings and if there was a nest failure. This document is related to correspondence and Wood Duck study report: https://avian.lib.iastate.edu/documents/3111/view , https://avian.lib.iastate.edu/documents/3112/view , and https://avian.lib.iastate.edu/documents/3113/view .
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frederic leopold letter to clarence w moody regarding a Wood Duck study march 29 1963
Avian Archives of Iowa Online, 2017Co-Authors: Leopold FredericAbstract:Letter from Frederic Leopold to Clarence W. Moody regarding a Wood Duck study, March 29, 1963. The letter informs Moody of an upcoming Wood Duck study that Leopold is launching. In an effort to attain more participants, Leopold is requesting Moody's assistance in writing a newspaper article to reach out to people who may be watching Wood Duck houses and would be willing to join the study. This document is related to additional correspondence, a Wood Duck study report and Wood Duck study materials: https://avian.lib.iastate.edu/documents/3112/view , https://avian.lib.iastate.edu/documents/3113/view , and https://avian.lib.iastate.edu/documents/3114/view .
Richard M Kaminski - One of the best experts on this subject based on the ideXlab platform.
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simulations of Wood Duck recruitment from nest boxes in mississippi and alabama
Journal of Wildlife Management, 2015Co-Authors: Brian J Davis, Richard M Kaminski, Jacob N Straub, Guiming Wang, Bruce D LeopoldAbstract:Since the early 20th century, wildlife managers have deployed artificial nesting structures for Wood Ducks (Aix sponsa) to increase availability of nest sites and local reproduction of the species. However, knowledge is lacking of the effects of nest structure size (i.e., large vs. small; Stephens et al. 1998) and reproductive data (e.g., clutch size, hatch date, Duckling survival) on recruitment of Wood Ducks. We used stochastic simulation analyses to predict recruitment of Wood Ducks into late summer by analyzing data from a 6-year study of box-nesting Wood Ducks, and 4-year (Mississippi) and 2-year (Alabama) studies of radio- marked female Wood Ducks and their Ducklings. Our index of recruitment was the number of radio-marked Ducklings per nest box that survived until 1 September. Ducklings hatched after 1 June exhibited a 30-day survival probability of 0.29, which was nearly 3 times greater than those hatched before 1 June. In east-central Mississippi, 68% and 65% of total Wood Duck recruits from large and small boxes, respectively, were hatched and reared from June to August. In western Mississippi, 91% of recruits from each box size also were hatched and reared from June to August. Mean number of Wood Duck recruits produced from large boxes was greater than small boxes at each study site; each large box in western Mississippi produced approximately 4 recruits on average, whereas small boxes in east-central Mississippi produced approximately 1 recruit. Wood Duck recruits in our study resulted primarily from late spring and summer hatched birds in contrast to most Nearctic Ducks with adaptive, early nesting to promote recruitment. In Mississippi and similar southern environments, we recommend use of large boxes and cleaning boxes around 1 May after completion of initial nests, and emphasize the importance of late spring and summer Duckling production to Wood Duck recruitment. © 2015 The Wildlife Society.
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Wood Duck Duckling mortality and habitat implications in floodplain systems
Wetlands, 2009Co-Authors: Brian J Davis, Richard M Kaminski, Bruce D Leopold, Robert R CoxAbstract:Abstract Floodplain ecosystems in the southeastern United States provide critical resources for resident and migratory populations of North American Wood Ducks (Aix sponsa). We studied radiomarked Wood Duck Ducklings and females that nested in artificial structures and used floodplain palustrine, riverine, and lacustrine wetlands at Noxubee National Wildlife Refuge (NNWR) in Mississippi in 1996–1999 and the Tennessee-Tombigbee Rivers and Waterway (TTRW) in Alabama in 1998–1999. We estimated cause-specific mortality rates for 234 and 90 mortality events of Wood Duck Ducklings at NNWR and TTRW, respectively. Composite estimates of Duckling mortality rate for the brood rearing period across years and areas were avian (0.46; n = 155), aquatic predators (0.23; n = 79), snakes (0.06; n = 21), mammals (0.05; n = 18), exposure-related (0.02; n = 7), and unknown causes (0.13; n = 44). Based on this and a concurrent study, we recommend the following: 1) conserving suitable brood habitats, specifically s...
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survival of Wood Duck Ducklings and broods in mississippi and alabama
Journal of Wildlife Management, 2007Co-Authors: Brian J Davis, Robert R Cox, Richard M Kaminski, Bruce D LeopoldAbstract:Abstract Although North American Wood Ducks (Aix sponsa) are well-studied throughout their range, researchers know little about demographic and environmental factors influencing survival of Ducklings and broods, which is necessary information for population management. We studied radiomarked female and Duckling Wood Ducks that used nest boxes and palustrine wetlands at Noxubee National Wildlife Refuge (NNWR) in Mississippi, USA, in 1996–1999, and riverine wetlands of the Tennessee-Tombigbee Rivers and Waterway (TTRW) system in Alabama in 1998–1999. We estimated survival of Ducklings and broods and evaluated potentially important predictors of Duckling survival, including age and body mass of brood-rearing females, hatch date of Ducklings, Duckling mass, brood size at nest departure, inter-day travel distance by Ducklings, site and habitat use, and daily minimum air temperature and precipitation. At NNWR, survival of 300 radiomarked Ducklings ranged from 0.15 (95% CI = 0.04–0.27) to 0.24 (95% CI = 0.13–0.3...
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evaluation of exodus rates of differently marked Wood Duck Ducklings from nest boxes
Wildlife Society Bulletin, 2001Co-Authors: Brian J Davis, Bruce D Leopold, Richard M KaminskiAbstract:Scientists often assume that marking animals for research and population management does not affect their behavior, mobility, and survival. Although numerous studies have examined the validity of this assumption on many bird species, few have examined effects of radio transmitters on neonate waterfowl. Our objective was to evaluate exodus rates of marked and unmarked Wood Duck (Aix sponsa) Ducklings from Wooden conventional (i.e., large) and experimental (i.e., small) nest boxes. Ducklings were either unmarked or marked with either 1) a back-mounted radiotransmitter and a web tag on one foot (radiomarked); 2) a plasticine-filled aluminum leg band on one leg and a web tag on the other foot (legbanded); or 3) 2 web tags, one on each foot (webtagged). We used 922 unmarked, 125 webtagged, 3,247 legbanded, and 308 radiomarked Wood Duck Ducklings to test hypotheses that exodus rates of differently marked and unmarked Ducklings from large and small nest boxes did not differ. We detected neither a box-mark type interaction (P=0.77) nor a separate effect of box and mark type on Duckling exodus (P> 0.61). Most (98-99%) Ducklings successfully exited nest boxes after hatch regardless of type of mark. Our results further support use of radiotransmitters and plasticine-filled legbands in studies of free-ranging Wood Duck Ducklings and young of other waterfowl species.
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Wood Duck reproduction in small and large nest boxes in mississippi a continued experiment
1999Co-Authors: Brian J Davis, Richard M Kaminski, Bruce D Leopold, Scott E Stephens, Patrick D GerardAbstract:Multi-year studies in wildlife science and management can provide novel in- sights not detected in short-term investigations. Therefore, we continued a 2-year study by Stephens et al. (1998) to evaluate Wood Duck (Aix sponsa) reproduction in conven- tional and small nest boxes (i.e., approximately one-half conventional size) at Noxubee and Yazoo National Wildlife Refuges (NWRs) in Mississippi. Small nest boxes were designed to deter excessive dump nesting by Wood Ducks at these refuges. During 1994-1997, use of large boxes by Wood Ducks remained high (&70%) at both study areas, but use of small boxes declined from 61% in 1994 to 34% in 1997 at Noxubee NWR. Concomitantly, use of small boxes by passerine birds increased from 14% to 65% at Noxubee NWR, but use of large boxes by passerines never exceeded 15%. Large boxes never were used by passerines at Yazoo NWR. Large boxes contained more Duck eggs and dump nests than small boxes, but Wood Duck nest success did not differ between the 2 box types. More Ducklings departed large boxes, but cost per Duckling was less from small than large boxes because of the lesser cost of constructing small boxes. Large and small boxes provide managers with choices for producing Wood Ducks and other birds relative to their objectives and financial resources.
Dale Crook - One of the best experts on this subject based on the ideXlab platform.
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Wood Duck and hooded merganser breeding success in nest boxes in ontario
Wildlife Society Bulletin, 2002Co-Authors: Mark L Mallory, Austin Taverner, Bill Bower, Dale CrookAbstract:Wood Ducks (Aix sponsa) and hooded mergansers (Lophodytes cucullatus) are common breeders in nest boxes in eastern Canada, but few studies have compared the breeding biology of these northern nesting birds to that of birds nesting to the south in the United States. We studied the breeding success of these species nesting in boxes near Ottawa, Ontario, Canada between 1986-1999. For Wood Ducks, mean annual box occupancy was 69% and mean clutch size was 12 eggs, with 60% of eggs hatched in a typical year. For nests with at least one egg hatching, hatching success was 83%. For hooded mergansers, mean box occupancy was 10% and mean clutch size was 10 eggs, with 64% of eggs hatched in an average year. For successful nests, hatching success was 87%. For both species, fewer eggs were hatched in years when the nest-box breeding population laid higher numbers of eggs. Despite the fact that this nest-box population was located near the northern limit of the Wood Duck breeding range, our results suggest that the basic nesting parameters of this population were similar to those of populations farther south.
