Felicia J. Sanders

Borrelia, Coxiella, and Rickettsia in Carios capensis (Acari: Argasidae) from a brown pelican (Pelecanus occidentalis) rookery in South Carolina, USA

Argasid ticks are vectors of viral and bacterial agents of humans and animals. Carios capensis, a tick of seabirds, infests the nests of brown pelicans, Pelecanus occidentalis, and other ground nesting birds along the coast of South Carolina. This tick is associated with pelican nest abandonment and could pose a threat to humans visiting pelican rookeries if visitors are exposed to ticks harboring infectious agents. We collected ticks from a pelican rookery on Deveaux Bank, South Carolina and screened 64 individual ticks, six pools of larvae, and an egg mass for DNA from Bartonella, Borrelia, Coxiella, and Rickettsia by polymerase chain reaction amplification and sequencing. Ticks harbored DNA from “Borrelia lonestari”, a novel Coxiella sp., and three species of Rickettsia, including Rickettsia felis and two undescribed Rickettsia spp. DNA from the Coxiella and two undescribed Rickettsia were detected in unfed larvae that emerged in the laboratory, which implies these agents are transmitted vertically by female ticks. We partially characterize the novel Coxiella by molecular means.

Molecular and Biological Characterization of a Novel Coxiella-like Agent from Carios capensis

Abstract: The genus Coxiella is currently defined by a single monotypic species, Coxiella burnetii. Novel Coxiella spp. have been detected in ticks throughout the world. These bacteria have not been cultured or named, and their evolutionary relationships to C. burnetii are poorly known. A novel Coxiella‐like agent was detected by PCR amplification and sequencing of DNA extracted from 64 pelican ticks, Carios capensis, from Devoux Bank, South Carolina, USA. PCR was used to amplify and characterize genes from the new bacterium. Sequences from some metabolic and housekeeping genes shared a 92–98% similarity to C. burnetii, but other genes such as the IS1111 transposon, com1, and 5S and 16S rRNA genes were not amplified by conventional PCR. Transovarial and transtadial transmission and environmental shedding of the agent were detected by PCR.

Breeding Season Abundance and Distribution of American Oystercatchers in South Carolina

Abstract Three statewide surveys in South Carolina for American Oystercatchers, Haematopus palliatus, were conducted during the breeding season from 2001-2003. A mean of 1,105 oystercatchers were recorded each year. In 2002, 407 breeding pairs were documented and in 2003, 397 pairs. There were 378 nonbreeding oystercatchers in 2002 and 383 in 2003. The Cape Romain Region supported a majority of South Carolina’s breeding pairs and nonbreeding flocks. Oystercatchers nested, on average, closer to each other on estuarine islands, (specifically made of shell) and farthest apart on edge shell mounds. Although historically oystercatchers may have nested primarily on front beaches, this study documented only 28% of the breeding pairs on barrier island beaches, 27% on estuarine islands and 45% on edge shell mounds. Twenty-four percent of all pairs in South Carolina were on edge shell mounds adjacent to the Atlantic Intracoastal Waterway (AIWW). Nesting on shell mounds may become increasingly important as beaches become more disturbed by humans and dogs.

HEALTH ASSESSMENT OF AMERICAN OYSTERCATCHERS (HAEMATOPUS PALLIATUS PALLIATUS) IN GEORGIA AND SOUTH CAROLINA

The American Oystercatcher (Haematopus palliatus palliatus) is the only species of oystercatcher native to the Atlantic coast of North America and is restricted in distribution to intertidal shellfish beds in coastal areas. Currently, the American Oystercatcher population in South Carolina and Georgia is threatened by widespread habitat loss, resulting in low reproductive success and small population size. Oystercatchers could be an important indicator of ecosystem health because they depend on quality coastal breeding habitat and prey on bivalves, which can accumulate toxins and pathogens from the local environment. Data were collected from American Oystercatchers (n=171) captured at five sites in South Carolina and Georgia between 2001 and 2006. Iridial depigmentation was frequently noted during physical examination and was more prevalent in female birds. Female birds were larger than males on average, but ranges for weight and morphometric measurements had considerable overlap. Mean values were calculated for hematology, plasma biochemistry, and hormone levels, and prevalence of exposure to select pathogens was determined. Mercury was the only trace metal detected in blood samples. These data provide baseline health information needed for longitudinal monitoring and conservation efforts for American Oystercatchers. In addition, this study illustrates the potential use of this species as an indicator for the health of the southeastern US coastal nearshore ecosystem.

FORAGING PROFICIENCY DURING THE NONBREEDING SEASON OF A SPECIALIZED FORAGER: ARE JUVENILE AMERICAN OYSTERCATCHERS "BUMBLE-BEAKS" 1 COMPARED TO ADULTS?

Abstract. In many species, immature individuals are less proficient at foraging than are adults, and this difference may be especially critical during winter when survival can be at its minimum. We investigated the foraging proficiency of adult and immature American Oystercatchers (Haematopus palliatus) during the nonbreeding season. Oystercatchers forage on prey that must be handled with specialized skills, so age-related differences in foraging behavior may be expected. We found that adults spent more time searching than did immatures, a trend toward immatures taking longer to handle prey than did adults, and immatures more often handling prey unsuccessfully than did adults. Feeding rates and diet composition did not differ by age class. We posit that the immature birds traded off longer handling times with shorter searching times and that ultimately the abundant prey in the region may contribute to the ability of immature birds to feed at rates similar to those of adults.

Daily Survival Rate for Nests and Chicks of Least Terns (Sternula antillarum) at Natural Nest Sites in South Carolina

Abstract. Although a species of conservation concern, little is known about the reproductive success of Least Terns (Sternula antillarum) throughout the southeastern USA where availability of natural beaches for nesting is limited. Daily survival rate (DSR) of nests and chicks was examined at four natural nesting sites in Cape Romain National Wildlife Refuge, South Carolina, 2009–2010. Measures of nest success (n = 257 nests) ranged from 0–93% among colony sites. The DSR of nests was primarily related to colony site, but year and estimates of predation risk also were related to DSR. Predation was the principal cause of identifiable nest loss, accounting for 47% of nest failures when the two years of data were pooled. The probability (± SE) of a chick surviving from hatching to fledging = 0.449 ± 0.01 (n = 92 chicks). DSR of chicks was negatively related to tide height and rainfall. Therefore, productivity of Least Terns is being lost during both the nesting and chick stage through a combination of biotic and abiotic factors that may prove difficult to fully mitigate or manage. Although natural nesting sites within Cape Romain National Wildlife Refuge intermittently produce successful nests, the consistency of productivity over the long term is still unknown. Given that the long term availability of anthropogenic nest sites (e.g., rooftops, dredge-spoil islands) for Least Terns is questionable, further research is required both locally and throughout the region to assess the extent to which natural sites act as population sources or sinks.

Parental Attendance and Brood Success in American Oystercatchers in South Carolina

Abstract. Research on breeding American Oystercatchers has focused on identifying factors that affect reproductive success but little attention has been paid to parent behavior during chick-rearing. Parental attendance of American Oystercatchers was measured in Bulls Bay and along the Atlantic Intracoastal Waterway (Waterway) within the Cape Romain Region, South Carolina, USA, during 2006. Parental attendance rates averaged 90.9% in Bulls Bay and 81.4% along the Waterway. Daily survival of chicks was higher in Bulls Bay (0.989 ± 0.007) compared to the Waterway (0.966 ± 0.012). The extent of shellfish reefs (i.e. foraging areas) adjacent to nest sites was greater in Bulls Bay (5,633 ± 658 m2) compared to the Waterway (3,273 ± 850 m2). Mean parental attendance in Bulls Bay was higher for successful broods (90.5%) compared to failed broods (79.8%). In contrast, mean parental attendance along the Waterway was higher for failed broods (93.4%) compared to successful broods (67.5%). Less extensive shellfish reefs adjacent to nest sites along the Waterway appeared to require parents to depart more frequently to forage and the resultant reduction in attendance may have negatively affected chick survival. Bulls Bay may provide higher quality nesting habitat compared to the Waterway with respect to proximity to food resources and parental attendance. Management and conservation efforts for American Oystercatchers should consider the relationship between foraging and nesting habitat and variability in behavioral attributes, such as parental attendance, in relationship to environmental conditions which ultimately affect reproductive success.

DAILY SURVIVAL RATE FOR NESTS OF BLACK SKIMMERS FROM A CORE BREEDING AREA OF THE SOUTHEASTERN USA

ABSTRACT Little is known about the reproductive success of Black Skimmers (Rynchops niger) throughout the southeastern USA where availability of undisturbed beaches for nesting is limited. Daily survival rates (DSR) of nests were examined at three nesting sites in Cape Romain National Wildlife Refuge (CRNWR), South Carolina, USA, 2009–2010. The percent of successful nests (n  =  346 nests) ranged from 42–69% among colony sites when data were pooled across both years. The DSR of nests was primarily related to colony site, predation risk, height of high tide, and clutch size. Predation and overwash were the principal causes of identifiable nest loss, each accounting for ∼33% of nest failures during the two study years. Because of the challenges of resighting skimmer chicks, we were not able to measure chick survival effectively and therefore accurate measures of productivity remain elusive. High variability in nest success among sites within close proximity to each other (<20 km) suggests factors at local scales such as disturbance, predation, and overwash events strongly influenced nest success of Black Skimmers during these 2 years as opposed to more region-wide stressors such as tropical storms or food availability. Although time-intensive techniques to control predators do exist, management options to limit flooding and overwash are far more limited. Conservation of Black Skimmers in the southeastern USA would benefit from coordinated, multi-state efforts to measure nest and chick survival.

Exploring Differences in Adult Survival and Site Fidelity of Migratory and Non-Migratory American Oystercatcher (Haematopus palliatus) Populations

Abstract. The conservation of a species is reliant on identifying threats to critical vital rates such as survival and dispersal. Accurate estimates of these vital rates and the factors that affect them can be used to better manage populations. The USA Atlantic Coast population of American Oystercatchers (Haematopus palliatus) benefits from a large-scale conservation effort, but this long-lived species remains especially sensitive to fluctuations in adult survival. The model used here and 8 years of mark-resight data from three breeding populations with varying migration strategies from the United States (migratory: Massachusetts and New Jersey; non-migratory: South Carolina) were used to estimate adult survival and site fidelity. Results indicated a resident population in South Carolina with 100% of the breeding population wintering in that State, a migratory population in Massachusetts with the majority of individuals wintering in Florida (42%), and a partially migratory population in New Jersey with a portion of the breeding population overwintering in that State (33%). Annual adult survival did not vary among populations. Although the average estimate of adult survival was high (0.89), there was an apparent decline in adult survival (from 0.94 to 0.83) over the study period. Given strong site fidelity (0.91), adult mortality is a critical factor for the viability of local populations.

Assessing conservation tools for an at-risk shorebird: Feasibility of headstarting for American Oystercatchers Haematopus palliatus

Management of threatened and endangered populations of wildlife increasingly relies upon active intervention such as predator control, habitat manipulation, and ex situ breeding or care. One tool that has received consideration for the management of declining or threatened avian populations is headstarting, or the artificial incubation of eggs and subsequent placement of newly hatched chicks in original or foster nests. We assessed the feasibility of implementing a headstarting program for the American Oystercatcher Haematopus palliatus , a species of high conservation concern in the eastern USA. Annual productivity is often low and lost during incubation, suggesting artificial incubation could enhance annual productivity. We used a control-impact approach to assign nests as either control or headstart and measured daily survival rate, success of parents accepting headstarted chicks, attendance patterns and behaviours of parents, and chick survival. We also implemented a transparent scoring process to rate the success of each step and the overall program. Daily survival rates of nests were significantly higher at headstart compared to control nests, and parents continued to incubate when eggs were well secured at nest sites. Attendance patterns and behaviour did not differ between headstart and control parents, and parents readily accepted healthy chicks whether they were returned to original or foster nests. Chick survival and subsequently annual productivity were, however, not higher at headstart compared to control nests suggesting that although we were able to enhance nest survival, low chick survival was still limiting annual productivity. Ultimately, headstarting may be most appropriate for American Oystercatchers where productivity is lost primarily to flooding, predation, or disturbance during the incubation stage but not during the chick-rearing stage. If, for example, high rates of nest loss are due to predators that also may prey upon chicks, then headstarting may not be an effective conservation tool.