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USGS2005

Ecology of Florida black bears in the Okefenokee-Osceola ecosystem

The population status of the Florida black bear ( Ursus americanus floridanus ) is problematic within many portions of its range and its potential listing as a federally threatened species has been the subject of legal debate. We studied Florida black bears in 2 areas in the Okefenokee-Osceola ecosystem in southeast Georgia (i.e.,Okefenokee) and north Florida (i.e., Osceola) from 1995 to 1999 to evaluate relationships between population characteristics, habitat conditions, and human activities. Bears in Okefenokee were hunted and those in Osceola were not. We captured 205 different black bears (124M:81F) 345 times from June 1995 to September 1998. We obtained 13,573 radiolocations from 87 (16M:71F) individual bears during the study. In Okefenokee, black gum ( Nyssa sylvatica ) and saw palmetto ( Serenoa repens ) fruits were the most important foods for bears based on scat analysis. In Osceola, corn from white-tailed deer ( Odocoileus virginianus ) feeders was the most stable food source but saw palmetto was heavily used when available. Corn from deer feeders was not available in Okefenokee. Adult bears in Osceola were 29% heavier than those in Okefenokee ( t 82 = 3.55, P <0.001). The mean annual home-range size for Osceola females ( x̄ =30.3 km 2 ± 4.0 [SE], n =53) varied little seasonally or annually and was almost half that of Okefenokee females (55.9 km 2 ± 6.9, n = 69; Z = –2.47, P = 0.014). In contrast, radiocollared females in Okefenokee expanded their home ranges during years of poor black gum production. That expansion was most apparent between autumn 1998 and 1999, when mean home-range size for Okefenokee females increased from 14.5 km 2 to 78.4 km 2 , respectively, and included a larger proportion of upland areas open to sport hunting. As a result, 5 females were harvested in the Okefenokee study area during the 1999 bear hunting season compared with only 7 harvested from 1996 to 1998. Home ranges of adult female bears were located in areas with disproportionately high loblolly bay ( Gordonia lasianthus ) and gum-bay-cypress ( Taxodium spp.) vegetation associations in Okefenokee and gum-bay-cypress associations in Osceola. The pine vegetation association ranked lower than most other associations within the home ranges of bears in both study areas even though much of the summer and autumn diets of bears included food items found almost exclusively in pine. Sixteen mortalities of radiocollared bears were documented in Okefenokee; hunting accounted for 11 (68.8%) of these deaths. The annual survival rate of radiocollared males in Okefenokee was 0.71 (95% CI = 0.53–0.88) whereas survival of females in Okefenokee was higher ( Z =18.87, P <0.001) at 0.89 (95% CI = 0.83–0.95). The survival rate for females in Osceola was 0.97 (95% CI = 0.92–1.00). Overall, 67 bears (51M:16F) were killed by hunters in the Okefenokee study area from 1995 to 1999. Based on all radiocollared bears in Okefenokee, many of which resided within areas closed to hunting, we estimated an annual harvest rate of 0.22 (95% CI = 0.03–0.37) for males and 0.07 (95% CI = 0.01–0.12) for females. When we excluded those bears that were not in areas open to hunting, however, the annual harvest rate rose to 0.37 (95% CI = 0.07–0.58) for males and 0.39 (95% CI = 0.09–0.58) for females. Following a black gum shortage in autumn 1995, only 1 of 15 radiocollared females in Okefenokee produced cubs in winter 1996. That low reproductive rate was in contrast to winter 1997, which followed heavy black gum production, when 21 of 22 radiocollared females produced cubs. Reproductive output was more consistent in the Osceola study area, with 46 cubs being produced from 8, 5, and 9 litters in 1997, 1998, and 1999, respectively. To estimate population size, we maintained 88 and 94 barbed-wire hair traps during 1999 in the Okefenokee and Osceola study areas, respectively. Using DNA collected at the hair traps, mark–recapture models produced estimates of 71 bears (95% CI = 59–91) in Okefenokee and 44 bears (95% CI = 40–57) in the Osceola study area during 1999. The estimated densities in the Okefenokee and Osceola study areas were 0.12 and 0.14 bears/km 2 , respectively. Alternative density estimates based on the amount of time bears spent within study area boundaries were similar (0.11 and 0.14 bears/km 2 on Okefenokee and Osceola, respectively). We used a population model to estimate the effect of harvest in the Okefenokee bear population. Excluding harvest, bears at Osceola experienced higher average annual population growth (λ = 1.184 ± 0.002) than those at Okefenokee (1.064 ± 0.002; t 18 = 3.93, P = 0.001), most likely due to protection from hunting and higher recruitment. Including the effects of emigration and immigration, we estimated an average annual sustainable harvest at Okefenokee of approximately 9 bears (12.6%), which was slightly less than the average 1995–1999 annual harvest of 9.4. That level of hunting in Okefenokee is sustainable but likely represents the highest exploitation rate in the region. Our mark–recapture data from Osceola suggest a high dispersal rate by subadult bears, and our population modeling data support this hypothesis; we documented bears in Okefenokee that originated from Osceola but not the reverse. We speculate that bears from the interior of the Okefenokee National Wildlife Refuge (ONWR), and to some extent northern Florida, served as a source to the population sink caused by hunting mortality in Okefenokee and in the surrounding Georgia counties. Corn from deer feeders was the most probable reason for smaller home-range sizes and greater body masses and reproductive output at Osceola. Changes in management to eliminate or reduce baiting for deer with corn would negatively affect the Osceola bear population. On Okefenokee, sporadic black gum and palmetto production influenced harvest rates and cub production and, thus, governed bear population dynamics. The U.S. Fish and Wildlife Service (USFWS) concluded in 1998 that listing the Florida black bear as threatened under the Endangered Species Act of 1973 was not warranted. That decision was largely based on the stability and protection afforded to a few subpopulations within the range of the subspecies, which includes the Okefenokee-Osceola subpopulation; our results support that conclusion. However, we suggest that metapopulation processes among the various subpopulations be given greater consideration, with the ultimate goal of managing the sub-species as a unit rather than as an assemblage of independent components. Our study illustrates the importance of travel corridors for maintaining metapopulation processes.

Florida, Georgia↗

USGS2007

Laysan Teal Anas laysanensis nesting phenology and site characteristics on Laysan Island

Factors influencing breeding initiation of the endangered Laysan Teal Anas laysanensis were studied on Laysan Island in the Hawaiian Islands National Wildlife Refuge between 1998 and 2006. Sixty-two radio-tagged adult females were tracked for 30-180 days to locate and describe their nest sites. In addition, the Laysan Teal were surveyed daily during the breeding season, and 331 individually colour-ringed females were marked to identify new broods and timing of incubation initiation. Temperature, rainfall, and abundance of Brine Flies (Scatella sexnotata, an important prey) were measured in all years. Females nested on average 213 m (s.e. ?? 37 m) from the lake basin primarily in Eragrostis variablis, a native bunch grass with > 75% cover. The first observation of nesting in marine debris by Laysan Teal was reported. The initiation of incubation, at the start of the breeding season each year, varied from December to July, and differed significantly between years. Brine Fly abundance, temperature, and rainfall also varied significantly between years. The earlier the Brine Fly abundance peaked, the longer the duration of the breeding season. The length of the breeding season, measured as the number of days between the first and last clutches, varied from 83-192 days (mean 116 ?? 14 days). Annual brood production was positively correlated with spring peak abundance of Brine Flies. There was some evidence that it was negatively correlated with the number of adult females in the population. Rainfall, temperature, prey abundance, and the density of other birds on Laysan Island are likely to interact in influencing Laysan Teal's variable nesting phenology and productivity. ?? Wildfowl & Wetlands Trust.

Wildfowl↗

USGS2007

Translocation of wild Laysan Teal Anas laysanensis from Laysan Island to Midway Atoll: Project update

The Laysan Teal Anas laysanensis is endemic to the Hawaiian Islands, where it has been restricted to Laysan Island over the last 150 years. Individuals of this endangered species have recently been translocated to the two largest islands that comprise Midway Atoll National Wildlife Refuge, to reduce the risk of the Laysan Teal becoming extinct. Post-release monitoring with the aid of radio-telemetry was conducted to determine the success of the reintroduction attempt during October 2004-2007. The population was found to have increased after three breeding seasons, from forty-two founders sourced directly from Laysan, to a population of ??? 192 post-fledglings juveniles and adults. ?? Wildfowl & Wetlands Trust.

Wildfowl↗

USGS2010

Scallopleaf sage (salvia vaseyi: Lamiaceae) discovered in Arizona

During the course of field work in Cabeza Prieta National Wildlife Refuge, southwestern Arizona, in 2003, James Cain and Brian Jansen collected Salvia vaseyi, previously known only from the western edge of the Sonoran Desert in California and Baja California. Our findings indicate this shrub might be more widespread in southwestern Arizona mountains. Salvia vaseyi in Arizona seems to represent a relict population. There are other shrubby Salvia in Arizona, but S. vaseyi is the most xeric-mhabiting species and has the narrowest ecological and geographical range.

Journal of the Botanical Research Institute of Tex↗

USGS2012

Sylvatic plague vaccine: combating plague in prairie dogs and black-footed ferrets

After achieving promising results in laboratory trials, researchers at the USGS National Wildlife Health Center (NWHC) and University of Wisconsin at Madison will soon begin field testing a new oral vaccine for sylvatic plague, a devastating disease affecting prairie dogs and other mammals, particularly the endangered black-footed ferret. Our team has developed and is currently registering a sylvatic plague vaccine (SPV) that uses raccoon poxvirus (RCN) to express two key antigens of the Yersinia pestis bacterium, the causative agent of plague.

The Wildlife Professional↗

USGS2008

Contaminant levels in eggs of American white pelicans, Pelecanus erythrorhynchos, from Chase Lake, North Dakota

American White Pelicans (Pelecanus erythrorhynchos) are colonial nesters, making them susceptible to site-specific mortality factors. One of the largest known breeding colonies is at Chase Lake National Wildlife Refuge in North Dakota. In 2004, this colony suffered total reproductive failure. In 2005, we collected abandoned eggs from this colony to test for environmental contaminants. Nine eggs were analyzed for 28 organochlorine pesticides, total polychlorinated biphenyls, and 26 inorganic elements. Based on concentrations in this sample of eggs and levels linked to reproductive problems in birds, adult pelicans in the Chase Lake breeding colony are not at known risk from any of the environmental contaminants we measured.

North Dakota↗

USGS2011

Prevalence of Mycoplasma ovipneumoniae in desert bighorn sheep in Arizona

To assess the potential for an epizootic of pneumonia to result from either natural immigration or translocation, we compared the seroprevalence to Mycoplasma ovipneumoniae in several populations of desert bighorn sheep in Arizona. We collected blood samples and nasal or oropharyngeal swabs from 124 desert bighorn sheep (Ovis canadensis nelsoni) from 6 populations in Arizona in 2009 and 2010. M. ovipneumoniae organisms were detected by PCR in 22%, whereas antibodies to M. ovipneumoniae were detected in 47% of tested bighorn sheep. Mycoplasma antibodies were not found in 2 of 6 populations, indicating some bighorn sheep populations in Arizona are naïve to this bacterium. In contrast, others had seroprevalence rates up to 80%. We were able to compare seroprevalence rates and titers over time in 9 individuals (7 individuals included in the 124 bighorn sheep sampled in 2009 and 2010, and 2 individuals originally captured in 2006). Antibody titers persisted for 12 months in individuals from the Kofa National Wildlife Refuge (n = 7) while antibody titers appeared to decline in the Kanab Creek population (n = 2). M. ovipneumoniae is present or has been present in several, but not all, populations of bighorn sheep in Arizona. The results demonstrate the importance of routine health testing for future translocation efforts to reduce disease risk for naive populations.

Arizona↗

USGS2012

Shorebird surveys in western Alaska

Surveys for breeding shorebirds were conducted during 2001-2002 in four National Wildlife Refuges (NWRs) in western Alaska - Alaska Maritime, Alaska Peninsula, Yukon Delta and Selawik. The sizes of our study areas on and adjacent to these four refuges were 9,243 km 2 , 24,493 km 2 , 853 km 2 , and 15,170 km 2 , respectively. Eleven sites were selected non-randomly, 3 in the Alaska Maritime NWR, 6 in the Alaska Peninsula, and one each in the other two NWRs. Survey and analytic methods are described in Chapter 2. Rapid surveys were conducted on 224 plots; 2,163 indicated pairs of shorebirds were recorded of which 1,485 were judged to be nesting in the surveyed plots. Detection ratios were estimated using intensive plot data from northern Alaska as well as from two plots on the Yukon Delta NWR. The highest estimated densities (shorebirds/km 2 ) were on the Yukon Delta Study Area: 416 in wetlands and 300 in moist areas. The estimated densities on the Alaska Peninsula Study Area were 118 in wetlands and 62 in uplands. Other densities were markedly lower. Estimated numbers of shorebirds were 62,000 (CV = 0.58), 1,804,000 (CV = 0.32), 310,000 (CV = 0.11), and 390,000 (CV = 0.35), in the Alaska Maritime, Alaska Peninsula, Yukon Delta, and Selawik study areas, respectively. The former two estimates were affected by selection bias of unknown magnitude and so should be regarded with caution. A small estimate was generated for the Yukon Delta Study Area because it covered only about 1% of the Yukon Delta NWR. We identify several species-specific estimates from our study which appear inconsistent with previous continental estimates. This pilot study provides preliminary estimates of species composition and density in the surveyed areas. By incorporating several region-specific modifications to the sampling protocols for future surveys, we believe that the Arctic PRISM method is suitable for covering large areas in western Alaska.

Alaska↗

USGS2013

Immunological markers for tolerance to avian malaria in Hawai`i `Amakihi: new tools for restoring native Hawaiian forest birds?

We evaluated three assays for non-specific or innate immune capacity to see if measurements were independent of malarial infection and capable of distinguishing malaria-tolerant, low-elevation Hawaiʽi ʽAmakihi from malaria-susceptible, high-elevation ʽAmakihi. ʽAmakihi were captured at Malama Ki Forest Reserve (20 m), Hakalau Forest National Wildlife Refuge (1800 m), and Upper Waiakea Forest Reserve (1700 m), bled for collection of plasma and packed erythrocytes for malarial diagnostics, and either transported to Kīlauea Field Station Aviary and held in captivity for 48 hours for inoculation of wing webs with phytohemagglutinin A (PHA) or released immediately in the field after collection of a blood sample. All birds were tested by polymerase chain reaction (PCR) and microscopy to determine infection status. We found no significant association between malarial infection status and degree of wing web swelling after inoculation with PHA (T = -0.174, df = 13, P = 0.864) and no association between origin of birds from low- and high-elevation populations and degree of wing web swelling (T = 0.113, df = 52, P = 0.911). Infected ʽAmakihi from low elevation had significantly higher small molecule plasma antioxidant capacity than uninfected individuals from the same population (T = -2.675, df = 21, P = 0.014), so we limited comparisons to uninfected birds. Uninfected ʽAmakihi from low elevations did not differ in small molecule plasma antioxidant capacity from uninfected ʽAmakihi from high elevation (T = -0.260, df = 46, P = 0.796). Compared to high-elevation birds, low-elevation ʽAmakihi had significantly higher titers of natural antibodies (NAb) as measured by complement-mediated lysis of rabbit erythrocytes (Mann-Whitney U = 27, X 2 = 32.332, df = 1, P < 0.0001). This innate immunological difference may be related to ability to survive malarial infection and may prove to be important for understanding possible mechanisms for the evolution of disease tolerance in Hawaiʽi’s native bird species.

Hawai'i↗

USGS2010

Behaviour of wintering Tundra Swans Cygnus columbianus columbianus at the Eel River delta and Humboldt Bay, California, USA

Tundra Swan Cygnus columbianus columbinanus phenology and behaviour at the Eel River delta and southern Humboldt Bay in northern California, USA, is described. Counts made each January from 1963 onwards peaked at 1,502 swans in 1988. Monthly counts recorded during the 2006/07 and 2008/09 winters peaked in February, at 1,033 and 772 swans respectively. Swans roosted on ephemeral ponds at the Humboldt Bay National Wildlife Refuge, on ephemeral ponds within grassland pastures in the vicinity of the Refuge, and perhaps also used the Eel River as a roost. Flights between Refuge roosts and the pastures and ponds occurred in the two hours after sunrise and before dark. In winters 2008/09 and 2009/10, the percentage of cygnets in the flocks was 10.6% and 21.4% respectively, and increased to =31% cygnets each year after most swans had departed from the area in March. Average brood size in 2009/10 was 2.1 cygnets. Daily activities consisted of foraging (44.9% of activities recorded), comfort behaviour (22.1%), locomotion (16.2%) and vigilance (15.5%). Eight neck-collared swans identified in the wintering flock were marked at four locations in different parts of Alaska, up to 1,300 km apart.

California↗

USGS2013

Avian disease assessment in seabirds and non-native passerines birds at Midway Atoll NWR

Midway Atoll in the Northwestern Hawaiian Islands supports the largest breeding colony of Laysan albatross ( Phoebastria immutabilis ) in the world and is a proposed site for the translocation of endangered Northwestern Hawaiian Island passerine birds such as the Nihoa finch ( Telespiza ultima ), Nihoa millerbird ( Acrocephalus familiaris kingi ), or Laysan finch ( Telespiza cantans ). On the main Hawaiian Islands, introduced mosquito-borne avian malaria ( Plasmodium relictum ) and avian pox ( Avipoxvirus ) have contributed to the extinction and decline of native Hawaiian avifauna. The mosquito vector ( Culex quinquefasciatus ) is present on Sand Island, Midway Atoll, where epizootics of Avipoxvirus have been reported among nestling Laysan albatross, black-footed albatross ( Phoebastria nigripes ), and red-tailed tropicbirds ( Phaethon rubricauda ) since 1963. Two introduced passerines, the common canary ( Serinus canaria ) and the common myna ( Acridotheres tristis ), are also present on Sand Island and may serve as reservoirs of mosquito-borne pathogens. Assessing disease prevalence and transmission potential at Midway Atoll National Wildlife Refuge (NWR) is a critical first step to translocation of Nihoa endemic passerines. In May 2010 and April 2012 we surveyed Midway Atoll NWR for mosquitoes and evidence of mosquito-borne disease. Although we did not observe active pox infections on albatross nestlings in May 2010, active infections were prevalent on albatross nestlings in April 2012. Presumptive diagnosis of Avipoxvirus was confirmed by PCR amplification of the Avipoxvirus 4b core protein gene from lesions collected from 10 albatross nestlings. Products were sequenced and compared to 4b core protein sequences from 28 Avipoxvirus isolates from the Hawaiian Islands and other parts of the world. Sequences from all Midway isolates were identical and formed a clade with other Avipoxvirus isolates from seabirds that was distinct from other Avipoxvirus isolates from the Hawaiian Islands. Tissue from three presumptive avian pox lesions from common canaries tested negative for Avipoxvirus . Blood samples from 124 canaries and 61 mynas tested negative for Plasmodium by one or more diagnostic tests based on microscopy, serology, or PCR diagnostics. Prevalence of Avipoxvirus infection was highest among albatross nestlings (94.6%) in the vicinity of the septic tanks where adult C. quinquefasciatus reached their highest densities, and data from all sites suggest a positive correlation between mosquito abundance and Avipoxvirus prevalence. Adult C. quinquefasciatus were also locally abundant around fishless, constructed wetlands. Since 1996, infrastructure removal and source reduction efforts by the refuge have greatly reduced the availability of underground and container habitats for larval mosquitoes on Sand Island. However, the creation of artificial wetlands and a central septic system on Sand Island has resulted in new, highly productive larval mosquito habitat for C. quinquefasciatus . Despite the presence of endemic Avipoxvirus in albatross nestlings and the introduction of mosquito vectors and two susceptible passerine species in the last century, we found no evidence of the avian malaria Plasmodium relictum or a passerine-infecting Avipoxvirus on Midway Atoll NWR that would interfere with the successful translocation of endemic Northwestern Hawaiian Island passerines. Without eradication of mosquitoes from Midway Atoll, however, periodic epizootics of Avipoxvirus among nestling seabirds will likely continue, and the introduction of malaria and passerine strains of Avipoxvirus from migratory birds will remain a long-term threat to passerine restoration programs.

Hawai'i↗

USGS2014

Monitoring Hawaiian waterbirds: evaluation of sampling methods to produce reliable estimates

We conducted field trials to assess several different methods of estimating the abundance of four endangered Hawaiian waterbirds: the Hawaiian duck ( Anas wyvilliana ), Hawaiian coot ( Fulica alai ), Hawaiian common moorhen ( Gallinula chloropus sandvicensis ) and Hawaiian stilt ( Himantopus mexicanus knudseni ). At two sites on Oʽahu, James Campbell National Wildlife Refuge and Hamakua Marsh, we conducted field trials where both solitary and paired observers counted birds and recorded the distance to observed birds. We then compared the results of estimates using the existing simple count, distance estimates from both point- and line-transect surveys, paired observer count estimates, bounded count, and Overton estimators. Comparing covariate recorded values among simultaneous observations revealed inconsistency between observers. We showed that the variation among simple counts means the current direct count survey, even if interpreted as a proportional index of abundance, incorporates many sources of uncertainty that are not taken into account. Analysis revealed violation of model assumptions that allowed us to discount distance-based estimates as a viable estimation technique. Among the remaining methods, point counts by paired observers produced the most precise estimates while meeting model assumptions. We present an example sampling protocol using paired observer counts. Finally, we suggest further research that will improve abundance estimates of Hawaiian waterbirds.

Hawai'i↗

USGS2013

Science-based management of public lands in southern Nevada

Landmark legislation provides guiding principles for land management planning in southern Nevada and the rest of the United States. Such legislation includes, but is not limited to, the Forest Service Organic Administration Act of 1897 (16 U.S>C. 473-478, 479-482 and 551), National Park Service Organic Act of 1916 (U.S.C. Title 16, Secs. 1-4). Wilderness Act 1964 (P.L.88-577), National Environmental Policy Act of 1969 (P.L. 91-190), Endangered Species Act of 1973 (P.L. 91-205), National Forest Management Act of of 1976 (P.L. 94-588), and Federal Land Policy and Management Act of 1976 (P.L. 94-579). The acts establishing congressionally designated areas within southern Nevada, such as Lake Mead National Recreation Area, Spring Mountains National Restoration Area, and Desert National Wildlife Refuge, also contain guidelines for the management of these lands. These documents variously require preservation of natural and cultural resource and wilderness character, protection of species, and prevention of undesirable environmental effects from land management actions. These requirements must be met while allowing for multiple "uses" of certain public lands (e.g. recreation, ranching, resources extraction, renewable energy development, etc.) to the degree that they do no threaten preservation, protection, and prevention goals,. many considerations some into play in the development and implementation for land management plans and actions. The planning process requires a balancing act that sometimes pit one need or priority against another. When priorities can trump other needs can prioritized and receive disproportionate consideration. Overall, the management of public lands is a very complicated and sometime contentious process. Science provides an objective way to help weigh quantifiable information and draw conclusions about the effects of past and potential future land management policies, decisions, and actions. When effectively integrated into adaptive management, science-based information can reduce uncertainties, increase knowledge, and improve decision making. However, the specific science information needed for effective management is often lacking or difficult to access or interpret. Science is typically reported in scientific journals as discrete units describing individual studies with other scientists as the primary audience. Translations of these studies an synthesis or multiple studies into formats that can be readily used in land management planning efforts are often lacking. Identifying and articulating the highest priority science and research needs is one of the primary purposes of the Southern Nevada Agency Partnership (SNAP; http://www.SNAP.gov) Science and Research Team (chapter 1; Turner and others 2009). The SNAP Science and Research Strategy (Strategy) calls for a synthesis report to be written every 5 years summarizing the state of knowledge, information gaps and management implications of scientific information as it relates to the SNAP Strategy goals (Turner and others 2009). This General Technical Report serves as the first SNAP Science and Research Synthesis Report (Synthesis Report) commissioned by the Science and Research Team. The Synthesis Report is mostly based on information form the peer-reviewed scientific literature, and is itself peer reviewed and constitutes a new contribution to the scientific literature. This final chapter addresses Sub-goal 2.3, which is to manage current and future authorized southern Nevada land uses in a manner that balances public need and ecosystem sustainability, and Sub-goal 2.5, which is to promote an effective conservation education and interpretation program to improve the quality of resources and enhance public use and enjoyment of southern Nevada public lands. It summarizes information form the previous chapters on what scientific information is known currently and what remains largely unknown, and it discusses how science can be used to make future management decisions that balances public needs and ecosystem sustainability.

Nevada↗

USGS2014

Productivity of forest birds at Hakalau Forest NWR

Hawai‘i has some of the most endangered avian species in the world, which face numerous threats from habitat loss, disease, climate change, and introduced species. This report details the results of a two-year productivity study of all forest bird species at Hakalau National Wildlife Refuge, Hawai‘i Island. We found and monitored nests from seven native species and three common non-native species of forest birds at three sites across the refuge. In addition to gathering important baseline information on productivity of forest birds, we examined differences in productivity between years, sites, and as a function of nest height. The weather differed greatly between the two years, with much more rain occurring in 2014. The daily survival rate (DSR) of nests was found to have an inverse relationship with the amount of rainfall, and accordingly was much lower in 2014 compared to 2013. Nest success was lower at a regenerating forest site compared with mature rainforest, indicating negative environmental factors affecting nest success may be exacerbated in reforested areas which have lower canopies. Nest success was also impacted by nest height, with a positive relationship in the drier 2013, and a negative relationship in 2014 for the canopy nesting honeycreepers. The large difference in weather and DSR between years illustrates the need for long term demographic studies that can capture the vital rates of this community of birds.

Hawaii↗

USGS2014

Distribution and prevalence of knemidokoptic mange in Hawai`i `Amakihi on the island of Hawaii

Knemidokoptic mange was first observed on two Hawai‘i ‘Amakihi (Hemignathus virens) mist netted in Manuka Natural Area Reserve (NAR) on the Island of Hawai‘i in June 2007. Microscopic examination of skin scrapings from lesions of the infested individuals revealed the scaley-leg mite, Knemidokoptes jamaicensis. Continued surveillance at Manuka NAR (2007-2009) documented a 24% (15/63) prevalence of mange among Hawai‘i ‘Amakihi distributed from coastal habitat to 1,500 m above sea level (asl). From 2012-2014, we conducted an island-wide survey of wild passerine birds from several leeward sites (Manuka NAR, Kahuku Unit of Hawai‘i Volcanoes National Park (HAVO), Pu‘u Wa‘awa‘a Forest Bird Sanctuary, and Kipahoehoe NAR) and windward sites (Hakalau Forest National Wildlife Refuge, ‘Ᾱinahou Ranch of HAVO, Malama Ki Forest Reserve, and Keauohana Forest Reserve) to determine the current distribution and host range of knemidokoptic mange. We also determined the prevalence of malaria in Hawai‘i ‘Amakihi populations where mange was present and treated a subset of infested Hawai‘i ‘Amakihi mange with a single, topical dose of moxidectin. We mist netted and examined a total of 1,734 passerines, including 738 Hawai‘i ‘Amakihi. Mange was present in Hawai‘i ‘Amakihi at Manuka NAR (595 and 305 m asl), Kahuku Ranch Unit of HAVO (Glover site: 1,201 m asl and Kipuka Akala site: 1,532 m asl), Malama Ki Forest Reserve and Keauohana Forest Reserve (293 m asl). No other passerine birds (n = 995) were infected. Mange prevalence ranged from a high of 69% (40/58) in Keauohana Forest Reserve to a low of 2% (1/65) in the Kahuku Ranch Unit of HAVO (Kipuka Akala). At Manuka NAR prevalence had decreased from 26% in 2010 to 10% (7/81) in 2012–2014. We found no significant relationship between the prevalence of mange and the prevalence of avian malaria in mesic habitats at Manuka NAR (P = 0.59 (FET, n = 81)), but there was a significant association between the prevalence of mange and the prevalence of malaria in lowland wet forests in Puna Forest Reserves (P < 0.01 (FET, n = 72)). This apparent association may be a reflection of the high prevalence of malaria (>80%) in these areas. There was no difference in the frequency of recapture of birds that were infested versus un-infested at first capture at our long-term sites (Manuka NAR and Puna sites) (χ2(1, n = 227) = 1.51, P = 0.22, but when all sites with mange present were pooled, there was a significant difference in the frequency of recaptures between infested and un-infested birds (χ2(1, n = 424) = 7.13, P = 0.01). There was a significant association between parasitemia level (per 10,000 RBCs) and the ranked stage of mange present in infested individuals. We treated 24 Hawai‘i ‘Amakihi with moxidectin and upon recapture (n = 2), found a reduction in both the size and stage of mange lesions, such that a single dose, topical treatment of moxidectin appears to be an effective treatment for knemidokoptic mange in wild populations. Our results suggest that knemidokoptic mange is currently limited to Hawai‘i ‘Amakihi and prevalent in low elevation sites on both the windward and leeward sides of the island.

Hawaii↗

USGS1995

Seabirds in Alaska

About 100 million seabirds reside in marine waters of Alaska during some part of the year. Perhaps half this population is composed of 50 species of nonbreeding residents, visitors, and breeding species that use marine habitats only seasonally (Gould et al. 1982). Another 30 species include 40-60 million individuals that breed in Alaska and spend most of their lives in U.S. territorial waters (Sowls et al. 1978). Alaskan populations account for more than 95% of the breeding seabirds in the continental United States, and eight species nest nowhere else in North America (USFWS 1992). Seabird nest sites include rock ledges, open ground, underground burrows, and crevices in cliffs or talus. Seabirds take a variety of prey from the ocean, including krill, small fish, and squid. Suitable nest sites and oceanic prey are the most important factors controlling the natural distribution and abundance of seabirds. The impetus for seabird monitoring is based partly on public concern for the welfare of these birds, which are affected by a variety of human activities like oil pollution and commercial fishing. Equally important is the role seabirds serve as indicators of ecological change in the marine environment. Seabirds are long-lived and slow to mature, so parameters such as breeding success, diet, or survival rates often give earlier signals of changing environmental conditions that population size itself. Seabird survival data are of interest because they reflect conditions affecting seabirds in the nonbreeding season, when most annual mortality occurs. Techniques for monitoring seabird populations vary according to habitat types and the breeding behavior of individual species (Hatch and Hatch 1978, 1989; Byrd et al. 1983). An affordable monitoring program can include but a few of the 1,300 seabird colonies identified in Alaska, and since the mid-1970's, monitoring effotrts have emphasized a small selection of surface-feeding and diving species, primarily kittiwakes ( Rissa spp.) and murres ( Uria spp.). Little or no information on trends is available for other seabirds (Hatch 1993a). The existing monitoring program occurs largely on sites within the Alaska Maritime National Wildlife Refuge, which was established primarily for the conservation of marine birds. Data are collected by refuge staff, other state and federal agencies, private organizations, university faculty, and students.

Alaska↗

USGS2010

Estimating salinity intrusion effects due to climate change on the Lower Savannah River Estuary

The ability of water-resource managers to adapt to future climatic change is especially challenging in coastal regions of the world. The East Coast of the United States falls into this category given the high number of people living along the Atlantic seaboard and the added strain on resources as populations continue to increase, particularly in the Southeast. Increased temperatures, changes in regional precipitation regimes, and potential increased sea level may have a great impact on existing hydrological systems in the region. The Savannah River originates at the confluence of the Seneca and Tugaloo Rivers, near Hartwell, Ga., and forms the state boundary between South Carolina and Georgia. The J. Strom Thurmond Dam and Lake, located 238 miles upstream from the Atlantic Ocean, is responsible for most of the flow regulation that affects the Savannah River from Augusta, Ga., to the coast. The Savannah Harbor experiences semi-diurnal tides of two low and two high tides in a 24.8-hour period with pronounced differences in tidal range between neap and spring tides occurring on a 14-day and 28-day lunar cycle. Salinity intrusion results from the interaction of three principal forces - streamflow, mean tidal water levels, and tidal range. To analyze, model, and simulate hydrodynamic behaviors at critical coastal streamgages in the Lower Savannah River Estuary, data-mining techniques were applied to over 15 years of hourly streamflow, coastal water-quality, and water-level data. Artificial neural network (ANN) models were trained to learn the variable interactions that cause salinity intrusions. Streamflow data from the 9,850 square-mile Savannah River Basin were input into the model as time-delayed variables. Tidal inputs to the models were obtained by decomposing tidal water-level data into a “periodic” signal of tidal range and a “chaotic” signal of mean water levels. The ANN models were able to convincingly reproduce historical behaviors and generate alternative scenarios of interest. Important freshwater resources are located proximal to the freshwater-saltwater interface of the estuary. The Savannah National Wildlife Refuge is located in the upper portion of the Savannah River Estuary. The tidal freshwater marsh is an essential part of the 28,000-acre refuge and is home to a diverse variety of wildlife and plant communities. Two municipal freshwater intakes are located upstream from the refuge. To evaluate the impact of climate change on salinity intrusion on these resources, inputs of streamflows and mean tidal water levels were modified to incorporate estimated changes in precipitation patterns and sea-level rise appropriate for the Southeastern United States. Changes in mean tidal water levels were changed parametrically for various sea-level rise conditions. Preliminary model results at the U.S. Geological Survey (USGS) Interstate-95 streamgage (station 02198840) for a 7½-year simulation show that historical daily salinity concentrations never exceeded 0.5 practical salinity units (psu). A 1-foot sea-level rise (ft, 30.5 centimeters [cm]) would increase the number of days of salinity concentrations greater than 0.5 psu to 47 days. A 2-ft (61 cm) sea-level rise would increase the number of days to 248.

Georgia, South Carolina↗

USGS2010

Potential mitigation approach to minimize salinity intrusion in the Lower Savannah River Estuary due to reduced controlled releases from Lake Thurmond

The Savannah River originates at the confluence of the Seneca and Tugaloo Rivers, near Hartwell, Ga. and forms the State boundary between South Carolina and Georgia. The J. Strom Thurmond Dam and Lake, located 187 miles upstream from the coast, is responsible for most of the flow regulation that affects the Savannah River from Augusta to the coast. The Savannah Harbor experiences semi-diurnal tides of two high and two low tides in a 24.8-hour period with pronounced differences in tidal range between neap and spring tides occurring on a 14-day and 28-day lunar cycle. The Savannah National Wildlife Refuge is located in the Savannah River Estuary. The tidal freshwater marsh is an essential part of the 28,000-acre refuge and is home to a diverse variety of wildlife and plant communities. The Southeastern U.S. experienced severe drought conditions in 2008 and if the conditions had persisted in Georgia and South Carolina, Thurmond Lake could have reached an emergency operation level where outflow from the lake is equal to the inflow to the lake. To decrease the effect of the reduced releases on downstream resources, a stepped approach was proposed to reduce the flow in increments of 500 cubic feet per second (ft 3 /s) intervals. Reduced flows from 3,600 ft 3 /s to 3,100 ft 3 /s and 2,600 ft 3 /s were simulated with two previously developed models of the Lower Savannah River Estuary to evaluate the potential effects on salinity intrusion. The end of the previous drought (2002) was selected as the baseline condition for the simulations with the model. Salinity intrusion coincided with the 28-day cycle semidiurnal tidal cycles. The results show a difference between the model simulations of how the salinity will respond to the decreased flows. The Model-to-Marsh Decision Support System (M2MDSS) salinity response shows a large increase in the magnitude (> 6.0 practical salinity units, psu) and duration (3-4 days) of the salinity intrusion with extended periods (21 days) of tidal freshwater remaining in the system. The Environmental Fluid Dynamic Code (EFDC) model predicts increases in the magnitude of the salinity intrusion but only to 2 and 3 psu and the intrusion duration greater than a week. A potential mitigation to the increased salinity intrusion predicted by the M2MDSS would be to time pulses of increase flows to reduce the magnitude of the intrusion. Seven-day streamflow pulses of 4,500 ft 3 /s were inserted into the constant 3,100 ft 3 /s streamflow condition. The streamflow pulses did substantially decrease the magnitude and duration of the salinity intrusion. The result of the streamflow pulse scenario demonstrates how alternative release patterns from Lake Thurmond could be utilized to mitigate potential salinity changes in the Lower Savannah River Estuary.

Georgia, South Carolina↗