Yukon-Kuskokwim Delta Research Articles

In Utero Exposure to Black Bull Chewing Tobacco and Neonatal Nicotine Withdrawal: A Review of the Literature

Among the indigenous people of the Yukon-Kuskokwim Delta area of Alaska, a homemade moist chewing tobacco known as Black Bull or "iq'mik" is widely used. Intake of various tobacco products is reported to be more than 80 percent in pregnant women throughout this area, with up to 60 percent of the pregnant women admitting to regular use of Black Bull. High levels of nicotine, cotinine, heavy metals, and other chemicals are known to pass to the fetus. Neonatal exposure to maternal tobacco use has been studied for the past three decades and has been shown to cause neonatal passive addiction and subsequent withdrawal symptoms. The intensified exposure and withdrawal experienced by infants passively subjected to Black Bull warrant further study.

Population ecology of breeding Pacific common eiders on the Yukon‐Kuskokwim Delta, Alaska

Les populations d'Eiders a duvet du Pacifique (Somateria mollissima v-nigrum) ont decline de 50-90% sur le delta du Yukon-Kuskokwim (DYK) dans l'ouest de l'Alaska entre 1975 et 1992 puis se sont stabilisees avec des faibles effectifs depuis le debut des annees 1990 jusqu'a aujourd'hui. Nous avons etudie les processus sous-jacents qui affectent la dynamique de ces populations en recoltant et en analysant les donnees demographiques des Eiders a duvet du Pacifique a 3 sites sur le DYK (1991-2004) pour un total de 29 site-annees. Nous avons examine la variation des parametres de la reproduction, teste des hypotheses concernant l'influence de certains facteurs ecologiques specifiques sur les traits d'histoire de vie et evalue leur contribution relative a la dynamique de la population locale. Le succes reproducteur etait faible et variable, tant pour un meme individu qu'entre les individus alors que la survie apparente des femelles adultes etait elevee et peu variable (0.89 ± 0.005). Tous les parametres reproductifs variaient entre les sites d'etude et les annees. Les dates d'initiation des nids s'etalaient du 4 mai au 28 juin, avec un pic (mode) d'initiation le 26 mai. Les femelles qui nichaient a un site insulaire initiaient toujours leurs nids 3-5 jours plus tot que les femelles nichant a 2 autres sites situes sur la terre ferme. La variance de la date d'initiation des nids pour la population etait negativement liee au pic suggerant une synchronisation accrue durant les annees plus tardives. En moyenne, la taille de ponte totale (pondue) variait entre 4.8 et 6.6 oeufs et declinait avec la date d'initiation du nid. En tenant compte de la predation partielle et des oeufs non-viables, le nombre moyen d'oeufs a l'eclosion variait entre 2.0 et 5.8. Pendant la saison de reproduction, la probabilite de survie journaliere (PSJ) des nids etait plus faible durant la ponte et pour les nids inities tardivement. L'estimation de la survie des nids variait considerablement entre les sites et les annees (moyenne = 0.55, ecart: 0.06-0.92), mais la variance du processus de la survie des nids etait relativement faible (0.02, IC: 0.01-0.05), indiquant que la majorite de la variance etait attribuable a l'erreur d'echantillonnage. Nous avons trouve que l'effet des observateurs pouvait reduire le succes global des nids de 0.0 a 0.36 a travers les site-annees. Les sites d'etude avec de plus faibles nombres d'echantillons et les plus frequemment visites semblaient subir un plus grand effet des observateurs. En general, les Eiders a duvet du Pacifique demontraient une grande variance dans leurs parametres de reproduction. Des tailles de ponte plus elevees et une survie des nids elevee pour les pontes initiees tot suggerent une selection directionnelle pour une nidification hâtive. Cependant, les effets environnementaux stochastiques peuvent masquer la reponse a cette force de selection. Nos resultats demontrent que les femelles qui se reproduisent tot en saison ont la plus grande valeur reproductive car elles pondent plus d'oeufs et ont la plus grande probabilite de les amener a eclosion. Nous avons developpe des modeles matriciels stochastiques structures en classes de stades qui incluent la variance spatio-temporelle observee (processus) et la co-variation des indices demographiques puis avons projete la distribution stable des classes de stades (w) et le taux de croissance de la population (X)

Body mass dynamics during incubation and duration of parental care in Pacific Dunlins Calidris alpina pacifica: a test of the differential parental capacity hypothesis

Breeding is energetically expensive and individuals face a trade‐off between current and future breeding investment. Due to their production of large eggs, female birds are thought to have substantially higher initial energetic investments than males, which decrease the female's offspring rearing capacity. The differential parental capacity hypothesis argues that this large initial investment limits the ability of female shorebirds to provide extended parental care, which can ultimately lead to offspring desertion. This hypothesis predicts that (1) during early incubation females will be in poorer condition than males, (2) both sexes will lose condition during incubation, but the decline in females will be slower than the decline in males and (3) there will be a positive relationship between female condition and the duration of maternal brood care. These predictions were tested using data on body mass adjusted for body size (as a proxy for condition) and parental care from Pacific Dunlins Calidris alpina pacifica nesting on the Yukon Kuskokwim Delta, Alaska. None of the predictions received support: females were heavier than males in early incubation, the overall pattern during incubation was that males gained mass while female mass remained relatively constant, and there was no relationship between female mass and maternal brood care duration. These results suggest that the factors influencing parental care decisions are more complex than a parent simply caring until it is physiologically unable to do so.

Risk Factors for Hospitalization With Lower Respiratory Tract Infections in Children in Rural Alaska

Lower respiratory tract infections (LRTIs) are a major cause of morbidity for children worldwide and particularly for children from developing and indigenous populations. In this study, we evaluated risk factors for hospitalization with LRTI in a region in southwest Alaska. The study was conducted from October 1, 2006, to September 30, 2007, in the Yukon Kuskokwim Delta region of Alaska. Cases were recruited from children <3 years of age hospitalized with LRTI. Controls were recruited during visits to the surrounding communities in the region and matched posthoc to cases on the basis of subregion, season, and age. Parents were interviewed for potential risk factors, and medical records were reviewed. Participants had a nasopharyngeal swab sample taken for polymerase chain reaction (PCR) testing for a panel of respiratory viruses. Samples positive for respiratory syncytial virus, human metapneumovirus, or parainfluenza type 3 were quantitated by reverse transcriptase real-time quantitative PCR. One hundred twenty-eight cases were matched to 186 controls. In a multivariable conditional logistic regression model, significantly (P < .05) increased risk of hospitalization was associated with medically high-risk status, having a woodstove in the house, being bottle fed, and vomiting after feeding; living in a house that had 2 or more rooms with sinks was a protective factor. Viral loads in hospitalized cases were significantly higher than those in controls, but a strict cutoff level was not observed. Several risk factors for LRTI hospitalization were identified in this high risk population. Some factors are amenable to environmental and behavioral interventions.

Tobacco Cessation Intervention During Pregnancy Among Alaska Native Women

This paper describes a community-based participatory research program with Alaska Native people addressing a community need to reduce tobacco use among pregnant women and children. Tobacco use during pregnancy among Alaska Native women is described along with development of a community partnership, findings from a pilot tobacco cessation intervention, current work, and future directions. Among Alaska Native women residing in the Yukon Kuskokwim Delta region of western Alaska, the prevalence of tobacco use (cigarette smoking and/or use of smokeless tobacco) during pregnancy is 79%. Results from a pilot intervention study targeting pregnant women indicated low rates of participation and less than optimal tobacco abstinence outcomes. Developing alternative strategies to reach pregnant women and to enhance the efficacy of interventions is a community priority, and future directions are offered.

Local Institutions for Subsistence Harvesting in Western Alaska: Assessing their Adaptive Role in the Context of Global Change

This article identifies key types of local institutions rural Alaska Native communities use to manage subsistence resources such as fish, game, and edible plants. Local institutions are the informal rules and norms communities use to manage these and other natural resources. Other scholars have mostly discussed them in the context of how they help subsistence users cope with ecological fluctuations in the abundance of certain species. The study presented here discusses them within a larger context of social and economic change. These local institutions were identified based on personal interviews with 62 active subsistence users in six different Yup’ik communities in the Yukon-Kuskokwim Delta region of Western Alaska. Participant-observation in subsistence activities like fishing and gathering supplemented the interview material. The key local institutions involve resource harvesting, resource processing, and resource sharing. The analysis of interview and observation data show that local institutions help households and communities cope with fluctuations in harvest amounts due to ecological perturbations, formal management regulations, and high fuel prices. Although local institutions can be fragile in the face of market pressures, and rationale for some institutions are not known by the younger generation, the strong role of sharing suggests that Yup’ik local institutions are expected to persist as climatic, environmental, economic, and social change continues.

Recent Trends in First-Year Survival for Black Brant Breeding in Southwestern Alaska

Abstract. We estimated first-year and adult survival of Black Brant (Branta bernicla nigricans) from the Yukon—Kuskokwim Delta, Alaska, to assess (1) the role that first-year survival plays in declining recruitment and in the local breeding population's decline since the early 1980s and (2) the potential role of subsistence harvest in declining first-year survival. We used band-recovery models in program Mark to estimate band-recovery rates and annual survival from 1986 to 2007. The only models of band recoveries that received support contained annual variation and an additive effect of sex on band-recovery rates. The two best-supported models of annual survival differentiated between first-year and older Black Brant. The best-supported model (Akaike weight = 0.69) included a linear trend in first-year survival, while the second best-supported model (Akaike weight = 0.20) included an effect of mean gosling mass on first-year survival. Band-recovery rates corresponded to harvest rates of ∼1%, indicating th...

Pacific Dunlin Calidris alpina pacifica show a high propensity for second clutch production

The Predation Danger Hypothesis suggests that shorebirds adjust aspects of their annual schedules to limit the amount of time they are exposed to the danger posed by the presence of Peregrine Falcons (Falco peregrinus) and other raptors. For example, Pacific Dunlin (Calidris alpina pacifica) remain near their breeding grounds on the Yukon-Kuskokwim Delta, Alaska to molt, and migrate southward after peak Peregrine Falcon migration has passed. This extended residence in the north may enable them to increase the time they devote to reproductive activities and enhancing their reproductive output, either by increasing the length of bi-parental brood care or by producing more clutches. In this paper, I describe the breeding ecology of Pacific Dunlin and relate my results to their migration strategy. Pacific Dunlin females deserted their broods, on average, at 5 days of age, leaving the remainder of the 19-day brood care period to their mates. This resembles the parental care patterns of other Calidris species. However, Pacific Dunlin exhibited a high propensity for replacing first clutches that failed (75%), and 17% of individuals who successfully hatched their first nest deserted their broods and went on to produce a clutch with a new mate (i.e., double brood). These rates are high compared to other subspecies of Dunlin suggesting that Pacific Dunlin take advantage of their extended time on the breeding grounds to increase their reproductive output.

Performance of a rapid antigen test (Binax NOW ® RSV) for diagnosis of respiratory syncytial virus compared with real-time polymerase chain reaction in a pediatric population

Background Infants from Alaska's Yukon–Kuskokwim Delta (YKD) have a high respiratory syncytial virus (RSV) hospitalization rate (104/1000/yr). Appropriate patient management requires rapid and accurate RSV diagnosis. Antigen-based methods are often used in clinical settings, but these tests can lack sensitivity. Objective We compared Binax NOW ® RSV (BN) used for RSV diagnosis in the YKD hospital with a real-time polymerase chain reaction assay (RT-qPCR) used for viral surveillance. Study design Between October 2005 and September 2007 we obtained nasopharyngeal washes (NPW) from children <3 years hospitalized with a lower respiratory tract infection. The NPW were tested using BN and RT-qPCR. Results 79/311 (25%) children had RSV infection as determined by RT-qPCR. As compared with RT-qPCR, sensitivity and specificity of BN were 72% and 97%, respectively. The sensitivity of BN was higher in children <1 year compared with children ≥1 year (79% vs. 52%; p = 0.025), children with bronchiolitis compared with children without bronchiolitis (89% vs. 38%; p < 0.001), and children with a shorter duration of symptoms before testing (0–1 (92%) vs. 2–4 (78%) vs. 5+ (65%) days; p = 0.04). The median RSV viral load in NPW positive by BN and RT-qPCR was 1.01 × 10 9 copies/mL vs. a median of 5.25 × 10 7 copies/mL for NPW positive by RT-qPCR only ( p < 0.001). Conclusion RT-qPCR is more sensitive than BN in detecting RSV infection. BN sensitivity is high in children with bronchiolitis, but the sensitivity is low when children present with a non-bronchiolitis illness, especially after a longer duration of symptoms before testing.

Reproductive Ecology and Habitat use of Pacific Black Scoters (Melanitta Nigra Americana) Nesting on the Yukon-Kuskokwim Delta, Alaska

Abundance indices of Black Scoters (Melanitta nigra. americana) breeding in Alaska indicate a long-term population decline without obvious cause (s). However, few life history data are available for the species in North America. In 2001–2004, information was collected on nesting habitat and reproductive parameters (i.e. components of productivity) from a population of Black Scoters nesting on the Yukon-Kuskokwim Delta, Alaska. A total of 157 nests were found over four years. Primarily, nests were among dense vegetation in shrub edge habitat, predominantly dwarf birch (Betula glandulosa) and Alaska spiraea (Spiraea beauverdiana), an average of 58 m from water. Females initiated nests from 11 June and 17 July across years. Clutch size averaged 7.5 eggs and did not vary annually. Nest success was highly variable among years and ranged from 0.01 to 0.37. Duckling survival to 30 days old varied among years, and ranged from 0.09 – 0.35. Nest success was poor in three of four years, likely due to predation by Red Fox (Vulpes vulpes). Black Scoters appear to have low but variable productivity, consistent with life-history patterns of other sea duck species. Information gained will direct future demographic research on Black Scoters, and highlights knowledge gaps impeding management strategies needed for population recovery.

Viral respiratory infections in hospitalized and community control children in Alaska

Respiratory syncytial virus (RSV) in Alaska Native children from the Yukon Kuskokwim (YK) Delta is associated with a hospitalization rate five times higher than that reported for the general US child population. The role of other viral respiratory pathogens has not been studied in this population. YK Delta children <3 years of age hospitalized with respiratory infections and same aged community control children were prospectively enrolled between October 2005 and September 2007. Polymerase chain reaction detection of viruses was performed on nasopharyngeal samples. Characteristics of hospitalized and asymptomatic control children were analyzed. From October 2005 to September 2007, 440 hospitalized and 425 control children were analyzed. Respiratory viruses were detected in 90% (395) of hospitalized children: 194 (44%) rhinovirus, 131 (30%) adenovirus, 102 (23%) RSV, 77 (18%) para influenza viruses (PIV), 66 (15%) human metapneumovirus (hMPV), 23 (5%) influenza, and 25 (6%) coronavirus. Fifty‐two percent (221) of control children had a virus detected, most commonly rhinovirus (33%), and adenovirus (16%). RSV, PIV, hMPV, and influenza were significantly more common in hospitalized cases than control children, but rhinovirus, adenovirus, and coronavirus were not. RSV and hMPV were associated with higher severity of illness. In this study, RSV remains the most important virus associated with respiratory hospitalization, although hMPV and PIV were also common. RSV and hMPV were associated with more severe illness. Rhinovirus and adenovirus were detected in two‐thirds of hospitalized children, but their frequent detection in control children made their role in respiratory hospitalization uncertain. J. Med. Virol. 82:1282–1290, 2010. © 2010 Wiley‐Liss, Inc.

Using Ethnoarchaeology and Soils Chemistry to Examine Fisheries on the Arctic Alaskan Coast

The Arctic coast is a critical region for archaeologists to understand how fisheries have impacted hunter-gatherer development. The Yukon-Kuskokwim Delta in southwestern Alaska is an ideal social and natural environment for archaeologists to study contemporary fisheries activity and their soils signatures. Here we discuss our combined methodological approach to studying fisheries among Native Yup'ik communities with a specific focus on the ethnographic component of our research. We suggest that fisheries-focused research promises to inform current models of coastal adaptation and behavior.

Feasibility of a tobacco cessation intervention for pregnant Alaska Native women.

Among Alaska Native women residing in the Yukon-Kuskokwim (Y-K) Delta region of Western Alaska, about 79% smoke cigarettes or use smokeless tobacco during pregnancy. Treatment methods developed and evaluated among Alaska Native pregnant tobacco users do not exist. This pilot study used a randomized two-group design to assess the feasibility and acceptability of a targeted cessation intervention for Alaska Native pregnant women. Recruitment occurred over an 8-month period. Enrolled participants were randomly assigned to the control group (n = 18; brief face-to-face counseling at the first visit and written materials) or to the intervention group (n = 17) consisting of face-to-face counseling at the first visit, four telephone calls, a video highlighting personal stories, and a cessation guide. Interview-based assessments were conducted at baseline and follow-up during pregnancy (>or=60 days postrandomization). Feasibility was determined by the recruitment and retention rates. The participation rate was very low with only 12% of eligible women (35/293) enrolled. Among enrolled participants, the study retention rates were high in both the intervention (71%) and control (94%) groups. The biochemically confirmed abstinence rates at follow-up were 0% and 6% for the intervention and control groups, respectively. The low enrollment rate suggests that the program was not feasible or acceptable. Alternative approaches are needed to improve the reach and efficacy of cessation interventions for Alaska Native women.

Using Videography to Quantify Landscape-Level Availability of Habitat for Grazers: An Example with Emperor Geese in Western Alaska

We present a videography approach to estimating large-scale availability of grazing lawns, an important food resource used by broods of emperor geese ( Chen canagica ) on the Yukon-Kuskokwim Delta, Alaska. Sampling was conducted in 1999, 2003, and 2004 at six locations that encompassed ~40% of the North American population of breeding emperor geese. We conducted ground truthing in 2003 and 2004 to estimate how accurately grazing lawn was classified. Overall, classification accuracy for grazing lawn and non-grazing lawn habitat was greater than 91%. Availability of grazing lawns was stable among years, but varied both among and within locations. Some locations have up to three times as much available grazing lawn, which in combination with densities of geese, likely represents dramatic variation in per capita food availability. Our results suggest that videography is a useful way to sample quickly across a large region and accurately identify fine-scale habitats. We present its use for estimating the availability of a preferred food resource for emperor geese, but the method could be applied to many other cases.

Population Dynamics of Long-tailed Ducks Breeding on the Yukon-Kuskokwim Delta, Alaska

Population estimates for long-tailed ducks in North America have declined by nearly 50% over the past 30 years. Life history and population dynamics of this species are difficult to ascertain, because the birds nest at low densities across a broad range of habitat types. Between 1991 and 2004, we collected information on productivity and survival of long-tailed ducks at three locations on the Yukon-Kuskokwim Delta. Clutch size averaged 7.1 eggs, and nesting success averaged 30%. Duckling survival to 30 days old averaged 10% but was highly variable among years, ranging from 0% to 25%. Apparent annual survival of adult females based on mark-recapture of nesting females was estimated at 74%. We combined these estimates of survival and productivity into a matrix-based population model, which predicted an annual population decline of 19%. Elasticities indicated that population growth rate (?) was most sensitive to changes in adult female survival. Further, the relatively high sensitivity of ? to duckling survival suggests that low duckling survival may be a bottleneck to productivity in some years. These data represent the first attempt to synthesize a population model for this species. Although our analyses were hampered by the small sample sizes inherent in studying a dispersed nesting species, our model provides a basis for management actions and can be enhanced as additional data become available.

Smoking, chewing, and cultural identity: Prevalence and correlates of tobacco use among the Yup’ik—The Center for Alaska Native Health Research (CANHR) study.

Survey data were obtained from a large sample of Yup'ik participants residing in the Yukon-Kuskokwim Delta region of Alaska. Tobacco use, age, sex, and a variety of psychosocial variables were assessed. Over 75% of participants use tobacco; one half (57.4%) reported using smokeless tobacco (SLT) regularly; 28.2% reported smoking cigarettes regularly. Relative to women, men reported using SLT less, smoking cigarettes more, and using the combination of cigarettes and SLT more. Younger participants tended to smoke cigarettes more, and to use the combination of cigarettes and SLT more. SLT users displayed significantly greater enculturation by identifying more with a Yup'ik lifestyle and less with a White lifestyle, speaking their traditional language more frequently, and consuming more traditional food and medicine. In contrast, smokers tended to display significantly greater acculturation and reported using drugs and alcohol more to cope with stress. Discussion focuses on appreciating the influence of cultural factors on health behavior and on implications for intervention.

The Annual Migration Cycle of Emperor Geese in Western Alaska

Most emperor geese (Chen canagica) nest in a narrow coastal region of the Yukon-Kuskokwim Delta (YKD) in western Alaska, but their winter distribution extends more than 3000 km from Kodiak Island, Alaska, to the Commander Islands, Russia. We marked 53 adult female emperor geese with satellite transmitters on the YKD in 1999, 2002, and 2003 to examine whether chronology of migration or use of seasonal habitats differed among birds that wintered in different regions. Females that migrated relatively short distances (650–1010 km) between the YKD and winter sites on the south side of the Alaska Peninsula bypassed autumn staging areas on the Bering Sea coast of the Alaska Peninsula or used them for shorter periods (mean = 57 days) than birds that made longer migrations (1600–2640 km) to the western Aleutian Islands (mean = 97 days). Alaska Peninsula migrants spent more days at winter sites (mean = 172 days, 95% CI: 129–214 days) than western Aleutian Island migrants (mean = 91 days, 95% CI: 83–99 days). Birds that migrated 930–1610 km to the eastern Aleutian Islands spent intermediate intervals at fall staging (mean = 77 days) and wintering areas (mean = 108 days, 95% CI: 95–119 days). Return dates to the YKD did not differ among birds that wintered in different regions. Coastal staging areas on the Alaska Peninsula may be especially important in autumn to prepare Aleutian migrants physiologically for long-distance migration to winter sites, and in spring to enable emperor geese that migrate different distances to reach comparable levels of condition before nesting.

Relationships between hepatic trace element concentrations, reproductive status, and body condition of female greater scaup

We collected female greater scaup ( Aythya marila) on the Yukon–Kuskokwim Delta, Alaska during two breeding seasons to determine if concentrations of 18 trace elements in livers and eggs were elevated and if hepatic concentrations correlated with body condition or affected reproductive status. Fifty-six percent, 5%, and 42% of females, respectively, had elevated hepatic cadmium (Cd: >3 μg g −1 dry weight [dw]), mercury (Hg: >3 μg g −1 dw), and selenium (Se: >10 μg g −1 dw). Somatic protein and lipid reserves were not correlated with hepatic Cd or Hg, but there was a weak negative correlation between protein and Se. Hepatic Cd, Hg, and Se were similar in females that had and had not initiated egg production. In a sample of six eggs, 33% and 100%, respectively, contained Se and Hg, but concentrations were below embryotoxicity thresholds. We conclude that trace element concentrations documented likely were not adversely impacting this study population.

Plasma Biochemistry Values in Emperor Geese (Chen canagica) in Alaska: Comparisons Among Age, Sex, Incubation, and Molt

Reduced populations of emperor geese (Chen canagica), a Bering Sea endemic, provided the need to assess plasma biochemistry values as indicators of population health. A precursory step to such an investigation was to evaluate patterns of variability in plasma biochemistry values among age, sex, and reproductive period. Plasma from 63 emperor geese was collected on their breeding grounds on the Yukon-Kuskokwim Delta in western Alaska, USA. The geese sampled included 18 incubating adult females captured, in mid June, on their nests by using bow nets, and 30 adults and 15 goslings captured in corral traps in late July and early August, when the adults were molting their wing feathers and the goslings were 5-6 weeks old. Plasma was evaluated for 15 biochemical parameters, by comparing results among age, sex, and sampling period (incubation versus wing-feather molt). Ten of the 15 biochemical parameters assayed differed among adults during incubation, the adults during molt, and the goslings at molt, whereas sex differences were noted in few parameters.

Differences in growth of Black Brant goslings between a major breeding colony and outlying breeding aggregations

Abstract We compared growth rates of Black Brant (Branta bernicla nigricans) goslings from two dispersed nesting aggregations to those from the large Tutakoke River Colony on the Yukon-Kuskokwim Delta, Alaska during summers, 1999 and 2000. Approximately 20% of the Black Brant population on the Yukon-Kuskokwim Delta, Alaska nests outside of the four major colonies. Dispersal to these outlying breeding locations is hypothesized as a mechanism by which individuals reduce the negative effects of density dependence associated with major colonies. Growth rates of goslings varied among brood rearing areas both associated with dispersed nesting aggregations (n = 4) and associated with the Tutakoke River Colony (n = 7). Mean mass of goslings, adjusted for age, from brood rearing areas associated with dispersed nesting aggregations ranked sixth, eighth, and ninth of nine brood rearing areas sampled in 1999, and sixth and ninth of nine brood rearing areas sampled in 2000. Mean age-adjusted mass of goslings with the ...