Seasonal Survival of Adult Female Mottled Ducks

The mottled duck (Anas fulgivula) is a non‐migratory duck dependent on coastal habitats to meet all of its life cycle requirements in the Western Gulf Coast (WGC) of Texas and Louisiana, USA. This population of mottled ducks has experienced a moderate decline during the past 2 decades. Adult survival has been identified as an important factor influencing population demography. Previous work based on band‐recovery data has provided only annual estimates of survival. We assessed seasonal patterns of female mottled duck survival from 2009 to 2012 using individuals marked with satellite platform transmitter terminals (PTTs). We used temperature and movement sensors within each PTT to indicate potential mortality events. We estimated cumulative weekly survival and ranked factors influential in patterns of mortality using known‐fate modeling in Program MARK. Models included 4 predictors: week; hunting and non‐hunting periods; biological periods defined as breeding, brooding, molt, and pairing; and mass at time of capture. Models containing hunt periods, during and outside the mottled duck season, comprised essentially 100% of model weights where both legal and illegal harvest had a negative influence on mottled duck survival. Survival rates were low during 2009–2011 (12–38% annual rate of survival), when compared with the long‐term banding average of 53% annual survival. During 2011, survival of female mottled ducks was the lowest annual rate (12%) ever documented and coincided with extreme drought. Management actions maximizing the availability of wetlands and associated upland habitats during hunting seasons and drought conditions may increase adult female mottled duck survival. © 2017 The Authors. Journal of Wildlife Management Published by Wiley Periodicals, Inc. on behalf of The Wildlife Society

Management regime and habitat response influence abundance of regal fritillary (Speyeria idalia) in tallgrass prairie

The \u3e2,570,000-ha Flint Hills ecoregion of Kansas, USA, harbors the largest remaining contiguous tract of tallgrass prairie in North America, a unique system, as the remainder of North America’s tallgrass prairie has succumbed to development and conversion. Consequently, the loss and degradation of tallgrass prairie has reduced populations of many North American prairie-obligate species including the regal fritillary (Speyeria idalia) butterfly. Population abundance and occupied range of regal fritillary have declined \u3e99%, restricting many populations to isolated, remnant patches of tallgrass prairie. Such extensive decline has resulted in consideration of the regal fritillary for protection under the Endangered Species Act. Although it is widely accepted that management practices such as fire, grazing, and haying are necessary to maintain prairie ecosystems, reported responses by regal fritillary to these management regimes have been ambiguous.We tested effects of prescribed fire across short, moderate, and long fire-return intervals as well as grazing and haying management treatments on regal fritillary density. We also tested the relative influence of habitat characteristics created by these management regimes by measuring density of an obligate host plant (Viola spp.) and canopy cover of woody vegetation, grasses, forbs/ferns, bare ground, and litter. We found density was at least 1.6 times greater in sites burned with a moderate fire-return interval vs. sites burned with short and long fire-return intervals. Overall management regardless of fire-return interval did not have an effect on density. Percent cover of grass had the strongest positive association, while percent cover of woody vegetation had the greatest negative effect on density. Our results indicate that patch-burning is a viable and perhaps even ideal management strategy for regal fritillary in tallgrass prairie landscapes. Additionally, these results elucidate the importance of fire, particularly when applied at moderate-return intervals to regal fritillary, and corroborate a growing suite of studies that suggest fire is perhaps not as detrimental to populations of regal fritillary as previously believed

Distribution of contaminants in the environment and wildlife habitat use: a case study with lead and waterfowl on the Upper Texas Coast

The magnitude and distribution of lead contamination remain unknown in wetland systems. Anthropogenic deposition of lead may be contributing to negative population-level effects in waterfowl and other organisms that depend on dynamic wetland habitats, particularly if they are unable to detect and differentiate levels of environmental contamination by lead. Detection of lead and behavioral response to elevated lead levels by waterfowl is poorly understood, but necessary to characterize the risk of lead-contaminated habitats. We measured the relationship between lead contamination of wetland soils and habitat use by mottled ducks (Anas fulvigula) on the Upper Texas Coast, USA. Mottled ducks have historically experienced disproportionate negative effects from lead exposure, and exhibit a unique nonmigratory life history that increases risk of exposure when inhabiting contaminated areas. We used spatial interpolation to estimate lead in wetland soils of the Texas Chenier Plain National Wildlife Refuge Complex. Soil lead levels varied across the refuge complex (0.01–1085.51 ppm), but greater lead concentrations frequently corresponded to areas with high densities of transmittered mottled ducks. We used soil lead concentration data and MaxENT species distribution models to quantify relationships among various habitat factors and locations of mottled ducks. Use of habitats with greater lead concentration increased during years of a major disturbance. Because mottled ducks use habitats with high concentrations of lead during periods of stress, have greater risk of exposure following major disturbance to the coastal marsh system, and no innate mechanism for avoiding the threat of lead exposure, we suggest the potential presence of an ecological trap of quality habitat that warrants further quantification at a population scale for mottled ducks

Effects of large-scale wetland loss on network connectivity of the Rainwater Basin, Nebraska

Context The Rainwater Basin region in south-central Nebraska supports a complex network of spatiallyisolated wetlands that harbor diverse floral and faunal communities. Since European settlement, many wetlands have been lost from the network, which has increased distances among remaining wetlands. As a result, populations of wildlife species with limited dispersal capabilities may have become isolated and face greater local extinction risks. Objectives We compared the pre-European settlement and current extent of the Rainwater Basin network to assess the effects of wetland losses on network connectivity for a range of maximum dispersal distances. Methods We constructed network models for a range of maximum dispersal distances and calculated network metrics to assess changes in network connectivity and the relative importance of individual wetlands in regulating flow. Results Since European settlement, the number of wetlands in the Rainwater Basin has decreased by[90%. The average distance to the nearest neighboring wetland has increased by 150% to * 1.2 km, and the dispersal distance necessary to travel throughout the whole network has increased from 3.5 to 10.0 km. Last, relative importance of individual wetlands depended on the maximum dispersal distance. Which wetlands to preserve to maintain connectivity might therefore depend on the dispersal capabilities of the species or taxa of interest. Conclusions To preserve a broad range of biodiversity, conservation efforts should focus on preserving dense clusters of wetlands at fine spatial scales to maintain current levels of network connectivity, and restoring connections between clusters to facilitate long-range dispersal of species with limited dispersal capabilities

Serologic detection of vaccine associate IgG responses in horses using a multiplex magnetic microsphere assay

Master of Science in Biomedical SciencesDepartment of Clinical SciencesElizabeth G. DavisTo protect horses from disease, equine practitioners typically prescribe a protocol of an initial primary vaccination followed by a booster vaccination 3-4 weeks later. Subsequent boosters are given every 6-12 months depending on the pathogen of concern. Each vaccination incurs an additional cost and increased chance for adverse reactions. Despite wide-spread protocol acceptance, duration of effectiveness of vaccines in protecting horses from disease is not well documented. It was hypothesized that horses vaccinated annually since birth have increased antibody production that remains consistent and sufficient for long-term protection from common diseases. This work resulted in the development of a novel, multiplex-magnetic bead-based indirect immunoassay to screen sera from vaccinated adult horses to measure antibody levels in response to vaccine administration. Antigens tested included West Nile Virus, Eastern Equine Encephalitis, Western Equine Encephalitis, Equine Influenza Virus, Equine Herpes Virus 1 and 4, Tetanus, and 7 different Rabies antigens (3 lab and 4 wild strains). The developed assay was a 7-plex capture antibody, which quantified equine IgG (Immunoglobulin G) that binds viral antigens derived from different rabies virus strains along with pure vaccine samples of the 7 different antigens. A 7-point standard curve was developed to quantify the viral-antigen reactive IgG concentration in vaccinated horse serum. Vaccinated horses increased serum antibody concentration for each antigen post-vaccination with the percent increase ranging between 34.0% for Equine Herpes Virus 4 and 257.3% for Equine Influenza Virus. Use of the novel assay will provide equine veterinarians with an economical method to measure immune activation toward common pathogens of concern. This methodology will provide foundation level information regarding antigen specific IgG concentrations that ultimately may be extrapolated to establish protective levels of immunity resulting in establishment of vaccine protocols

Nonbreeding Duck Use at Central Flyway National Wildlife Refuges

Within the U.S. portion of the Central Flyway, the U.S. Fish and Wildlife Service manages waterfowl on numerous individual units (i.e., Refuges) within the National Wildlife Refuge System. Presently, the extent of waterfowl use that Refuges receive and the contribution of Refuges to waterfowl populations (i.e., the proportion of the Central Flyway population registered at each Refuge) remain unassessed. Such an evaluation would help determine to what extent Refuges support waterfowl relative to stated targets, aid in identifying species requiring management attention, inform management targets, and improve fiscal efficiencies. Using historic monitoring data (1954–2008), we performed this assessment for 23 Refuges in Texas, New Mexico, Oklahoma, Kansas, and Nebraska during migration and wintering months (October–March). We examined six dabbling ducks and two diving ducks, plus all dabbling ducks and all diving ducks across two periods (longterm [all data] and short-term [last 10 October–March periods]). Individual Refuge use was represented by the sum of monthly duck count averages for October–March. We used two indices of Refuge contribution: peak contribution and January contribution. Peak contribution was the highest monthly count average for each October–March period divided by the indexed population total for the Central Flyway in the corresponding year; January contribution used the January count average divided by the corresponding population index. Generally, Refuges in Kansas, Nebraska, and New Mexico recorded most use and contribution for mallards Anas platyrhynchos. Refuges along the Texas Gulf Coast recorded most use and contribution for other dabbling ducks, with Laguna Atascosa and Aransas (including Matagorda Island) recording most use for diving ducks. The long-term total January contribution of the assessed Refuges to ducks wintering in the Central Flyway was greatest for green-winged teal Anas crecca with 35%; 12–15% for American wigeon Mareca americana, gadwall Mareca strepera, and northern pintail Anas acuta; and 7–8% for mallard and mottled duck Anas fulvigula. Results indicated that the reliance on the National Wildlife Refuge System decreased for these ducks, with evidence suggesting that, for several species, the assessed Refuges may be operating at carrying capacity. Future analyses could be more detailed and informative were Refuges to implement a single consistent surveymethodology that incorporated estimations of detection bias in the survey process, while concomitantly recording habitat metrics on and neighboring each Refuge

Snowy Plover Nest Site Selection, Spatial Patterning, and Temperatures in the Southern High Plains of Texas

Snowy plover (Charadrius nivosus) populations have declined throughout their range, in part because of habitat degradation and poor nest success, making information regarding regionally specific nest site selection and spatial patterns important when considering habitat conservation and management guidelines. We determined nest site selection characteristics (n=80) and examined spatial patterns (n=215) of snowy plover nests in saline lakes in the Southern High Plains (SHP) of Texas. At 104 nests, we examined the influence of substrate type on nest temperatures and heat mitigation. Snowy plover nests were more likely to be found near an object, on pebble substrate, and with fewer plants than random sites. High use areas were generally located in areas with pebble substrate and on human-made or natural islands, berms, and peninsulas. Overall, nests placed on pebble substrate had lower temperatures during the day than nests placed on sand substrates. Nest placement on pebble substratemay be valuable to nesting snowy plovers, providing thermal advantages to incubating adults and depressing potentially high nest predation rates. Management guidelines for this region should emphasize the importance of addressing key elements of snowy plover nesting habitat including the presence of pebble substrate and reducing vegetation encroachment

Spatiotemporal Distribution of Waterfowl Disease Outbreaks in Kansas, USA

Causes and impacts of disease outbreaks in wild bird populations are rarely studied beyond documentation of large epizootic events. In Kansas, USA, a central disease surveillance and reporting protocol currently does not exist within the Kansas Department of Wildlife, Parks and Tourism, which has led to a lack of available knowledge of disease occurrences that could be used to predict and manage future outbreaks. We compiled historic records of documented waterbird disease outbreaks in Kansas from 1967–2014 and related the frequency of outbreaks with light geese (Ross’s goose [Anser rossii]; Snow goose [A. caerulescens]) populations from 1970–2014. We found 32 reports across 16 counties that documented various outbreaks of avian cholera, avian botulism, aspergillosis, renal coccidiosis, West Nile, aflatoxicosis, and mycotoxicosis across multiple waterbird taxa. Avian cholera and avian botulism represented nearly 70% of documented disease outbreaks. Frequency of disease outbreaks increased across the time period with a positive relationship between annual Midwinter Waterfowl Survey counts of light geese and number of reported of avian cholera outbreaks in Kansas. Changes in the continental abundance and distribution of light geese has resulted in increasing residence times in Kansas during winter, potentially increasing risk and severity of avian cholera outbreaks. Disease mitigation efforts by the Kansas Department of Wildlife, Parks and Tourism (KDWPT) should strategically plan for future avian disease outbreaks

Spatiotemporal Distribution of Waterfowl Disease Outbreaks in Kansas, USA

Causes and impacts of disease outbreaks in wild bird populations are rarely studied beyond documentation of large epizootic events. In Kansas, USA, a central disease surveillance and reporting protocol currently does not exist within the Kansas Department of Wildlife, Parks and Tourism, which has led to a lack of available knowledge of disease occurrences that could be used to predict and manage future outbreaks. We compiled historic records of documented waterbird disease outbreaks in Kansas from 1967–2014 and related the frequency of outbreaks with light geese (Ross’s goose [Anser rossii]; Snow goose [A. caerulescens]) populations from 1970–2014. We found 32 reports across 16 counties that documented various outbreaks of avian cholera, avian botulism, aspergillosis, renal coccidiosis, West Nile, aflatoxicosis, and mycotoxicosis across multiple waterbird taxa. Avian cholera and avian botulism represented nearly 70% of documented disease outbreaks. Frequency of disease outbreaks increased across the time period with a positive relationship between annual Midwinter Waterfowl Survey counts of light geese and number of reported of avian cholera outbreaks in Kansas. Changes in the continental abundance and distribution of light geese has resulted in increasing residence times in Kansas during winter, potentially increasing risk and severity of avian cholera outbreaks. Disease mitigation efforts by the Kansas Department of Wildlife, Parks and Tourism (KDWPT) should strategically plan for future avian disease outbreaks