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USGS2013

Adaptive harvest management for the Svalbard population of pink-footed geese: cooperator report

This document describes progress to date on the development of a harvest‐management strategy for maintaining pink‐footed goose abundance near their target level by providing for sustainable harvests in Norway and Denmark. Many goose populations in western Europe have increased dramatically in recent decades. The Svalbard population of pink‐footed geese (Anser brachyrhynchus) is a good example, increasing from about 10 thousand individuals in the early 1960’s to roughly 80 thousand today. Although these geese are a highly valued resource, the growing numbers of geese are causing agricultural conflicts in wintering and staging areas. The African‐Eurasian Waterbird Agreement (AEWA; http://www.unep‐aewa.org/) calls for means to manage populations which cause conflicts with certain human economic activities. We compiled relevant demographic and weather data and specified an annual‐cycle model for pink-footed geese that reconciles the different dates of monitoring activities and the timing of harvest-management decisions. We then developed dynamic models for survival and reproductive processes and parameterized them using available data. By combining varying hypotheses about survival and reproduction, we developed a suite of nine models that represent a wide range of possibilities concerning the extent to which demographic rates are density dependent or independent, and the extent to which spring temperatures are important. These nine models varied significantly in their predictions of the harvest required to stabilize current population size, ranging from a low of about 500 to a high of about 17 thousand. For comparison, the harvest in Norway and Denmark was about 11 thousand in 2011 and the population increased from 70 to 80 thousand. We relied on the passive form of adaptive management in formulating a harvest strategy. In passive adaptive management, alternative population models and their associated weights of evidence are explicitly considered in the development of an optimal harvest strategy. Unlike active adaptive management, however, there is no explicit consideration of how harvest management actions could reduce uncertainty as to the most appropriate model of population dynamics. In optimizing a harvest strategy, we assumed equal probabilities for all nine models and assumed relatively course control over harvest. We used a management objective that seeks to maximize sustainable harvest, but avoids harvest decisions that are expected to result in a subsequent population size different than the population goal of 60 thousand. Optimal harvest strategies were calculated using stochastic dynamic programming, and Monte Carlo simulations were used to investigate expected strategy performance. The optimal passive adaptive‐management strategy is expected to maintain mean population size near 60 thousand, regardless of the most appropriate model. However, mean harvest rates and harvests varied substantially depending on the most appropriate model of population dynamics. With an average number of days above freezing in May in Svalbard, optimal harvest rates (i.e., the proportion of the population to be harvested in autumn) increase rapidly once there are more than about 50 thousand birds in the population. Generally, optimal harvests were on the order of 10 – 20 thousand for population sizes > 60 thousand, and 0 – 5 thousand for population sizes < 60 thousand. For the observations of young of 15.4 thousand and adults of 54.6 thousand in autumn 2010, and 10 days above freezing in May 2011 (a relatively warm spring compared to the average of about 7), the optimal harvest rate in autumn of 2011 would have been 0.16, or a harvest of about 14 thousand. Based on the optimal strategy, hunting‐season closures would be required as the number of adults in the autumn population falls below about 52 thousand, regardless of the number of young in the population. As the number of adults and young decrease, the number of warm days in May required to keep the hunting season open increases. We also investigated the ability of the optimal strategy to stabilize the population at around 60 thousand birds, assuming varying values of the maximum harvest rate that could be implemented. Harvest strategies that contained a maximum harvest rate of 0.16 (equivalent to a harvest of about 17 thousand) were effective at stabilizing the population at 60 thousand within 4‐5 years, regardless of climate scenario. Harvest strategies with a maximum harvest rate of 0.12 (harvest ≈ 13 thousand) were also able to stabilize the population near 60 thousand, although it took more time. Harvest strategies with a maximum harvest rate of 0.08 (harvest ≈ 8 thousand) were unsuccessful at stabilizing the population at 60 thousand. Continued monitoring of the pink‐footed goose population on an annual basis is critical to an informed harvest management strategy. At a minimum, the ground census in November should be continued to determine population size and proportion of young. Continued estimates of harvest from Norway and Denmark are also necessary to help judge the credibility of the alternative population models. However, an adaptive management process that relies on periodic updating of model weights will depend on acquiring either estimates of the realized harvest rate of adults or the age composition of the harvest. We also recommend that a census conducted during spring migration be operationalized, and that estimates of survival based on mark‐recapture data be updated. Finally, the International Working Group has expressed a desire to adopt a three‐year cycle of decision making related to the regulation of pink‐footed goose harvests. The idea is that once a target harvest level is adopted, it would remain in place for three years, after which time population status would be assessed and a potentially new management action chosen. We have developed a preliminary framework to implement a three‐year cycle using stochastic dynamic programming, and we hope to have it fully operational later this year . We note, however, that application of this 3‐year framework will still require annual resource monitoring and assessments to facilitate learning, and to allow managers the opportunity to respond to any unforeseen change in resource conditions.

Report↗

USGS2014

Lake trout rehabilitation in Lake Ontario, 2013

Each year we report on the progress toward rehabilitation of the Lake Ontario lake trout ( Salvelinus namaycush ) population, including the results of stocking, annual assessment surveys, creel surveys, and evidence of natural reproduction observed from all standard surveys performed by USGS and NYSDEC. No lake trout from the 2011 year class were stocked into Lake Ontario during October 2011 or May 2012; therefore, no stocked age-2 lake trout were available to bottom trawls during 2013. The catch per unit effort of adult lake trout in gill nets increased each year from 2008-2013, recovering from historic lows recorded during 2005-2007. Adult abundance in 2013 exceeded the level of the 1999-2004 mean which at the time appeared to be the new stable abundance following from the 1993 stocking cuts. The 2013 rate of wounding by sea lamprey ( Petromyzon marinus ) on lake trout caught in gill nets was 2.26 fresh (A1) wounds per 100 lake trout and was slightly above target (2 wounds per 100 lake trout). Estimates from the NYSDEC fishing boat survey indicated 2013 angler catch and harvest rates were the highest estimated in more than 10 years. Adult lake trout condition (indexed from annual length–weight regressions) increased in 2007-2009 from relatively low values observed during 2000-2006, remained nearly constant during 2010-2012 at the highest values observed for the 30 year time-series, but declined in 2013. The low condition values observed for juvenile lake trout during 2010-2012 continued during 2013. Reproductive potential for the adult stock, determined from the annual egg deposition index, rebounded from the 2007-2008 values that were the lowest observed since 1985 and stabilized during 2009-2013 at a mean value of 20.7. In 2013, five age-1 and three age-2 naturally produced lake trout were collected from trawl survey catches providing first evidence of a 2012 year class and continued evidence of a 2011 year class.

Lake Ontario↗

USGS2010

Evidence of mating readiness in certain bats killed by wind turbines

Bats consistently die at wind turbines during late-summer and autumn. Migratory, tree-roosting species show increased susceptibility compared to other bats, yet the exact causes remain unknown. A hypothesized cause with strong conservation implications is that migratory tree bats die at turbines while seeking mates around tall tree like structures. In this pilot study we histologically examined reproductive tracts of hoary bats ( Lasiurus cinereus ) and silver-haired bats ( Lasionycteris noctivagans ), found dead beneath wind turbines, for evidence of mating or mating readiness. We sampled 61 L. cinereus and 31 L. noctivagans killed by turbines in New York, USA, and Alberta and Manitoba, Canada between early July and late September. By August most adult male L. cinereus had sperm in the caudae epididymides (CE), indicating readiness to mate. About half of juvenile male hoary bats had sperm in their CE by August, revealing reproductive activity just months after birth. Sperm were seen in the uterus ofthe only adult female hoary bat collected in September, but we found no sperm in the other 17 females sampled in previous months. Ovaries of most adult and juvenile female L. cinereus had growing follicles, but they did not appear to be in estrus. Evidence of sperm in L. noctivagans was more limited, yet sperm were found in the CE of some adult and juvenile males. No female L. noctivagans contained sperm, but most adults and juveniles had growing follicles. These results indicate that adult and juvenile males of each species were ready to mate when they were killed by wind turbines, although evidence of copulation with females was limited. Results were insufficient to disprove the mating hypothesis - more thorough analysis of bats killed by turbines from late August through October and from a broader geographic area will be the next important step in assessing its merit.

Conference Paper↗

USGS1986

Morphological variation and zoogeography of racers ( Coluber constrictor ) in the central Rocky Mountains

We examined 63 specimens of Coluber constrictor from Colorado and Utah using eight external morphological characters that have been used to distinguish C. c. mormon from C. c. flaviventris . We grouped the snakes into three Operational Taxonomic Units (OTU's) in a transect across the Rocky Mountains: the eastern Front Range foothills in Colorado; the inter-mountain region (western slope of Colorado and northeastern Utah); and the western foothills of the Wasatch Mountains in Utah. Statistically significant variation among the OTU's was discovered for ration of tail length to total length, number of central and subcaudal scales, and number of dentary teeth. However, variation is clinal with nearly complete overlap from one end f the transect to the other for each character, suggesting a wide zone of intergradiation in the inter-mountain region. We do not believe reported differences in reproductive parameters between Great Plains and Great Basin racers are sufficient grounds for recognition of species, because clutch size is both geographically variable and dependent on the environment. The distribution of C. constrictor is similar to that of other reptiles with transmontane distributions in the western United States, and we suggest two possible routes of dispersal across the Continental Divide in southwestern Wyoming. Thus, elevation of C. c. mormon to species status is not supported by morphological, reproductive, or zoogeographic evidence.

Colorado;Utah↗

USGS1989

The brown tree snake, an introduced pest species in the central Pacific Islands

The reproduction of endangered Mariana crows ( Corvus kubaryi ) is intensively monitored, nests are protected, and (when necessary) eggs or young are moved to the safety of lab conditions until they are less vulnerable to the threats in natural habitats. Barriers on tree trunks and judicious pruning of adjacent trees are used in attempts to exclude snakes from nest trees. Two birds unique to Guam--the Micronesian kingfisher ( Halcyon cinnamomina cinnamomina ) and Guam rail ( Gallirallus owstoni )-- are maintained at captive propagation facilities on Guam and in mainland zoos. Studies of these and other species, in captivity and on nearby islands, are underway to bolster our biological understanding of their behavior, reproduction, habitat use, and population biology.

Endangered Species Technical Bulletin↗

USGS2012

Fire in Mediterranean climate ecosystems-A comparative overview

Four regions of the world share a similar climate and structurally similar plant communities with the Mediterranean Basin. These five areas, known collectively as "mediterranean-type climate (MTC) regions", are dominated by evergreen sclerophyllous-leaved shrublands, semi-deciduous scrub, and woodlands, all of which are prone to widespread crown fires. Summer droughts produce an annual fire hazard that contributes to a highly predictable fire regime. Fire has been an important factor driving the convergence of these systems and is reflected in plant traits such as lignotubers in resprouting shrubs and delayed reproduction that restricts recruitment to a postfire pulse of seedlings. On fertile soils where postfire resprouting is very rapid, opportunities for postfire seedling recruitment are limited and thus these woody taxa have not opted for delaying reproduction. Such fire-independent recruitment is widespread in the floras of MTC regions of the Mediterranean Basin and California and postfire seeding tends to dominate at the more arid end of the gradient. Due to very different geological histories in South Africa and Western Australia, substrates are nutrient poor and thus postfire resprouters do not pose a similar competitive challenge to seedlings and thus postfire seeding is very widespread in these floras. Although circumstantial evidence suggests that the MTC region of Chile had fire-prone landscapes in the Tertiary, these were lost with the late Miocene completion of the Andean uplift, which now blocks summer lightning storms from moving into the region. Today these five regions pose a significant fire management challenge due to the annual fire hazard and metropolitan centers juxtaposed with highly flammable vegetation. This challenge varies across the five MTC landscapes as a function of differences in regional fuel loads and population density.

Israel Journal of Ecology and Evolution↗

USGS2013

Demography and population status of polar bears in western Hudson Bay

We evaluated the demography and population status of the Western Hudson Bay (WH) polar bear subpopulation for the period 1984-2011, using live-recapture data from research studies and management actions, and dead-recovery data from polar bears harvested for subsistence purposes or removed during human-bear conflicts. We used a Bayesian implementation of multistate capture-recapture models, coupled with a matrix-based demographic projection model, to integrate several types of data and to incorporate sampling uncertainty, and demographic and environmental stochasticity across the polar bear life cycle. This approach allowed for estimation of a suite of vital rates, including survival and reproduction. These vital rates were used to parameterize a Bayesian population model to evaluate population trends and project potential population outcomes under different environmental scenarios. Survival of female polar bears of all age classes was significantly correlated with sea ice conditions; particularly with the timing of sea ice break-up in the spring and formation in the fall and the interaction of the two. This is consistent with previous findings linking body condition and survival of WH polar bears to environmental changes associated with climatic warming and supports the ecological dependence of polar bears on the availability of sea ice. Survival of male polar bears was not correlated with sea ice conditions. This was likely because a higher proportion of mortality for males was caused by humans rather than by natural factors. For example, approximately 73% of mortality for young male bears (i.e., 5-9 years old) was due to direct human-caused removals, largely because of sex selectivity in the subsistence harvest. The declining trend in size of the WH subpopulation over the period 1987-2004 was similar to a previous analysis (Regehr et al. 2007), suggesting consistency between the two demographic evaluations. Point estimates of abundance were somewhat lower using the updated statistical approach. It is important to recognize that the analyzed data were not collected in a manner that is optimal for estimating abundance and that the goal of the current analysis was to estimate vital rates and demographic trends. Estimates of population growth rate were also derived using a Bayesian population model based on estimated survival and reproductive rates from the multistate capture-recapture model. For the recent decade 2001-2011, the growth rate of the female segment of the population was 1.02 (95% CI = 0.98-1.06). Apparently stable to positive population growth for females may be due in large part to nonlinearity (i.e., short-term stability) in the long-term observed and forecasted trend toward earlier sea ice break-up in western Hudson Bay. The 2011 abundance estimate from this analysis was 806 bears with a 95% Bayesian credible interval of 653-984. This is lower than, but broadly consistent with, the abundance estimate of 1,030 (95% confidence interval = 745-1406) from a 2011 aerial survey (Stapleton et al. 2014). The capture-recapture and aerial survey approaches have different spatial and temporal coverage of the WH subpopulation and, consequently, the effective study population considered by each approach is different.

Report↗

USGS2015

Family Bovidae (Hollow-horned Ruminants)

Probably the single most eye-catching aspect of the current volume is the explosion of species recognized in the family Bovidae (Hollow-horned Ruminants). In 2005, the third edition of Mammal Species of the World listed 143 species in 50 genera of Bovidae. That list, prepared by the late Peter Grubb, was somewhat traditional and provisional, as he was engaged with his long-time colleague, Colin Groves, in a substantial revision of ungulate taxonomy. Their work, which will be published later this year, is the culmination of years of study of this important and wide-ranging family by these two venerable authorities. Colin Groves is the lead author for Bovidae in this volume of HMW, and in it we recognize all 279 species in 54 genera that are documented in his and Peter Grubb’s ground-breaking work. At the root of this expanded number of recognized species is our changing view of the modern species concept. Like a growing number of taxonomists, Groves favors a phylogenetic species concept, which he defines as the smallest population or aggregation of populations that has fixed heritable differences from other such populations or aggregations. This is in contrast to the traditional biological species concept, which requires reproductive isolation between such populations. The difficulty in determining that reproductive isolation led to an underrepresentation of the number of species in many groups. Clearly there remain problems in determining which differences between populations are heritable, and the system used here undoubtedly will continue to be tweaked as our understanding grows. For now, this greatly expanded version of Bovidae species limits seems the best answer. One of the goals of HMW is to provide an up-to-date summary of the conservation status for every species of mammal, and this expanded species concept better enables us to explore the true conservation situation of each.

Book chapter↗

USGS2015

Adaptive harvest management for the Svalbard population of pink-footed geese: 2015 progress summary

This document describes progress to date on the development of an adaptive harvest management strategy for maintaining the Svalbard population of pink‐footed geese (Anser brachyrhynchus) near their agreed target level (60,000) by providing for sustainable harvests in Norway and Denmark. This report provides an assessment of the most recent monitoring information (1991-2014) and its implications for the harvest management strategy, and it is an update of an initial assessment for 2013-2015 (see http://pinkfootedgoose.aewa.info/). By combining varying hypotheses about survival and reproduction, a suite of nine models have been developed that represent a wide range of possibilities concerning the extent to which demographic rates are density dependent or independent. Current updated model weights suggest little evidence for density-dependent survival and reproduction, suggesting that the population may have recently experienced a release from density-dependent mechanisms, corresponding to the period of most rapid growth in population size. The optimal harvest strategy for the 2013–2015 hunting seasons prescribed a harvest quota of 15,000 per year. The harvest in the 2014 hunting season was 14,991, compared to 11,081 in 2013, mostly due to an increase in harvest in Denmark during January 2015. The percentage of young in the fall of 2014 was 10.3%, which is lower than average. The observed population size of 59,000 in May 2015 was much lower than expected. For the 2015 hunting season, observed population size and temperature days suggest that an emergency closure should be considered. In the event a harvest of 15,000 is maintained, predicted population size in May 2016 is 51,700 (95% CL: 41,600-64,300), based on observed TempDays = 9 in May 2015 and the most recent model weights. On the other hand, if the season were closed this year, we would expect a population size of 66,700 (95% CL: 53,600-82,900) in May 2016. A total harvest of 6,700 would be expected to result in a 2016 population size at goal (i.e., 60,000).

Technical Report from DCE - Danish Centre for Envi↗

USGS2015

Evaluation of the toxicity of sediments from the Anniston PCB Site to the mussel Lampsilis siliquoidea

The Anniston Polychlorinated Biphenyl (PCB) Site is located in the vicinity of the municipality of Anniston in Calhoun County, in the north-eastern portion of Alabama. Although there are a variety of land-use activities within the Choccolocco Creek watershed, environmental concerns in the area have focused mainly on releases of PCBs to aquatic and riparian habitats. PCBs were manufactured by Monsanto, Inc. at the Anniston facility from 1935 to 1971. The chemicals of potential concern (COPCs) in sediments at the Anniston PCB Site include: PCBs, mercury, metals, polycyclic aromatic hydrocarbons (PAHs), organochlorine and organophosphorous pesticides, volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), and polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/PCDFs). The purpose of this study was to evaluate the toxicity of PCB-contaminated sediments to the juvenile fatmucket mussel (Lampsilis siliquoidea) and to characterize relationships between sediment chemistry and the toxicity of sediment samples collected from the Anniston PCB Site using laboratory sediment testing. Samples were collected in August 2010 from OU-4 of the Anniston PCB Site, as well as from selected reference locations. A total of 32 samples were initially collected from six test sites and one reference site within the watershed. A total of 23 of these 32 samples were evaluated in 28-day whole-sediment toxicity tests conducted with juvenile mussels (L. siliquoidea). Physical and chemical characterization of whole sediment included grain size, total organic carbon (TOC), nutrients, PCBs, parent and alkylated PAHs, organochlorine pesticides, PCDD/PCDFs, total metals, simultaneously extracted metals (SEM), and acid volatile sulfide (AVS). Sediment collected from Snow Creek and Choccolocco Creek contained a variety of COPCs. Organic contaminants detected in sediment included PCBs, organochlorine pesticides, PCDDs/PCDFs, and PAHs. In general, the highest concentrations of PCBs were associated with the highest concentrations of PAHs, PCDDs/PCDFs, and organochlorine pesticides. Specifically, sediments 08, 18, and 19 exceeded probable effect concentration quotients (PEC-Qs) of 1.0 for all organic classes of contaminants. These three sediment samples also had high concentrations of mercury and lead, which were the only metals found at elevated concentrations (i.e., above the probable effect concentration [PEC]) in the samples collected. Many sediment samples were highly contaminated with mercury, based on comparisons to samples collected from reference locations. The whole-sediment laboratory toxicity tests conducted with L. siliquoidea met the test acceptability criteria (e.g., control survival was greater than or equal to 80%). Survival of mussels was high in most samples, with 4 of 23 samples (17%) classified as toxic based on the survival endpoint. Biomass and weight were more sensitive endpoints for the L. siliquoidea toxicity tests, with both endpoints classifying 52% of the samples as toxic. Samples 19 and 30 were most toxic to L. siliquoidea, as they were classified as toxic according to all four endpoints (survival, biomass, weight, and length). Mussels were less sensitive in toxicity tests conducted with sediments from the Anniston PCB Site than Hyalella azteca and Chironomus dilutus. Biomass of L. siliquoidea was less sensitive compared to biomass of H. azteca or biomass of larval C. dilutus. Based on the most sensitive endpoint for each species, 52% of the samples were toxic to L. siliquoidea, whereas 67% of sediments were toxic to H. azteca (based on reproduction) and 65% were toxic to C. dilutus (based on adult biomass). The low-risk toxicity threshold (TTLR) was higher for L. siliquoidea biomass (e.g., 20,400 µg/kg dry weight [DW]) compared to that for H. azteca reproduction (e.g., 499 µg/kg DW) or C. dilutus adult biomass (e.g., 1,140 µg/kg DW; MacDonald et al. 2014). While mussels such as L. sili

Alabama↗

USGS2007

Tower counts

Counting towers provide an accurate, low-cost, low-maintenance, low-technology, and easily mobilized escapement estimation program compared to other methods (e.g., weirs, hydroacoustics, mark-recapture, and aerial surveys) (Thompson 1962; Siebel 1967; Cousens et al. 1982; Symons and Waldichuk 1984; Anderson 2000; Alaska Department of Fish and Game 2003). Counting tower data has been found to be consistent with that of digital video counts (Edwards 2005). Counting towers do not interfere with natural fish migration patterns, nor are fish handled or stressed; however, their use is generally limited to clear rivers that meet specific site selection criteria. The data provided by counting tower sampling allow fishery managers to determine reproductive population size, estimate total return (escapement + catch) and its uncertainty, evaluate population productivity and trends, set harvest rates, determine spawning escapement goals, and forecast future returns (Alaska Department of Fish and Game 1974-2000 and 1975-2004). The number of spawning fish is determined by subtracting subsistence, sport-caught fish, and prespawn mortality from the total estimated escapement. The methods outlined in this protocol for tower counts can be used to provide reasonable estimates ( plus or minus 6%-10%) of reproductive salmon population size and run timing in clear rivers.

Book chapter↗

USGS2016

Preserving reptiles for research

What are voucher specimens and why do we collect them? Voucher specimens are animals and/or their parts that are deposited in a research museum to document the occurrence of a taxon at a specific location in space and time (Pleijel et al., 2008; Reynolds and McDiarmid, 2012). For field biologists, vouchers are the repeatable element of a field study as they allow other biologists, now and in the future, to confirm the identity of species that were studied. The scientific importance of a voucher specimen or series of specimens is that other people are afforded the opportunity to examine the entire animal and confirm or correct identifications. A photographic record is somewhat useful for recording the occurrence of a species, but such records can be insufficient for reliable confirmation of specific identity. Even if a photo shows diagnostic characters of currently recognized taxa, it may not show characters that separate taxa that may be described in the future. Substantial cryptic biodiversity is being found in even relatively well-known herpetofaunas (Crawford et al., 2010), and specimens allow researchers to retroactively evaluate the true diversity in a study as understanding of taxonomy evolves. They enable biologists to study the systematic relationships of populations by quantifying variation in different traits. Specimens are also a source of biological data such as behaviour, ecology, epidemiology, and reproduction through examination of their anatomy, reproductive and digestive tracts, and parasites (Suarez and Tsutsui, 2004). Preserving reptiles as vouchers is not difficult, although doing it properly requires care, effort, and time. Poorly preserved vouchers can invalidate the results and conclusions of your study because of the inability to confirm the identity of your study animals. Good science requires repeatability of observations, and the absence of vouchers or poorly preserved ones prevents such confirmation. Due to space restrictions, we are unable to go into as much detail as we would like in this chapter. A number of publications give more details on some topics discussed in this chapter, such as Pisani (1973), Pisani and Villa (1974), Etheridge (1996), Karns (1986), McDiarmid (1994), Cortez et al. (2006), Foster (2012) (and subchapters therein), Reynolds and McDiarmid (2012), and Simmons (2015). Although some of these works focus on amphibians, they also apply to reptiles in many aspects.

Book chapter↗

USGS2014

Status of whitebarkpine in the Greater Yellowstone Ecosystem: A step-trend analysis comparing 2004-2007 to 2008-2011

Whitebark pine (Pinus albicaulis) is a foundation and keystone species in upper subalpine environments of the northern Rocky Mountains that strongly influences the biodiversity and productivity of high-elevation ecosystems (Tomback et al. 2001, Ellison et al. 2005). Throughout its historic range, whitebark pine has decreased significantly as a major component of high-elevation forests. As a result, it is critical to understand the challenges to whitebark pine—not only at the tree and stand level, but also as these factors influence the distribution of whitebark pine across the Greater Yellowstone Ecosystem (GYE). In 2003, the National Park Service (NPS) Greater Yellowstone Inventory & Monitoring Network identified whitebark pine as one of twelve significant natural resource indicators or vital signs to monitor (Jean et al. 2005, Fancy et al. 2009) and initiated a long-term, collaborative monitoring program. Partners in this effort include the U.S. Geological Survey, U.S. Forest Service, and Montana State University with representatives from each comprising the Greater Yellowstone Whitebark Pine Monitoring Working Group. The objectives of the monitoring program are to assess trends in (1) the proportion of live, whitebark pine trees (>1.4-m tall) infected with white pine blister rust (blister rust); (2) to document blister rust infection severity by the occurrence and location of persisting and new infections; (3) to determine mortality of whitebark pine trees and describe potential factors contributing to the death of trees; and (4) to assess the multiple components of the recruitment of understory whitebark pine into the reproductive population. In this report we summarize the past eight years (2004-2011) of whitebark pine status and trend monitoring in the GYE. Our study area encompasses six national forests (NF), two national parks (NP), as well as state and private lands in portions of Wyoming, Montana, and Idaho; this area is collectively described as the GYE here and in other studies. The sampling design is a probabilistic, twostage cluster design with stands of whitebark pine as the primary units and 10x50 m belt transects as the secondary units. Primary sampling units (stands) were selected randomly from a sample frame of approximately 10,770 mapped pure and mixed whitebark pine stands ≥2.0 hectares in the GYE (Dixon 1997, Landenburger 2012). From 2004 through 2007 (monitoring transect establishment or initial time-step), we established 176 permanent belt transects (secondary sampling units=176) in 150 whitebark pine stands and permanently marked approximately 4,740 individual trees >1.4 m tall to monitor long-term changes in blister rust infection and survival rates. Between 2008 and 2011 (revisit time-step), these same 176 transects were surveyed and again all previously tagged trees were observed for changes in blister rust infection and survival status. Objective 1. Using a combined ratio estimator, we estimated the proportion of live trees infected in the GYE in the initial time-step (2004-2007) to be 0.22 (0.031 SE). Following the completion of all surveys in the revisit time-step (2008-2011), we estimated the proportion of live trees infected with white pine blister rust as 0.23 (0.028 SE; Table 2). We detected no significant change in the proportion of trees infected in the GYE between the two time-steps. Objective 2. We documented blister rust canker locations as occurring in the canopy or bole. We compared changes in canker position between the initial time-step (2004-2007) and the revisit time-step (2008-2011) in order to assess changes in infection severity. This analysis included the 3,795 trees tagged during the initial time-step that were located and documented as alive at the end of the revisit time-step. At the end of the revisit time-step, we found 1,217 trees infected with blister rust. This includes the 287 newly tagged trees in the revisit time step of which 14 had documented infections. Of these 1,217 trees, 780 trees were infected with blister rust in both time steps. Trees with only canopy cankers made up approximately 43% (519 trees) of the total number of trees infected with blister rust at the end of the revisit time-step, while trees with only bole cankers comprised 20% (252 trees), and those with both canopy and bole cankers included 37% (446 trees) of the infected sample. A bole infection is considered to be more consequential than a canopy canker, as it compromises not only the overall longevity of the tree, but its functional capacity for reproductive output as well (Kendall and Arno 1990, Campbell and Antos 2000, McDonald and Hoff 2001, Schwandt and Kegley 2004). In addition to infection location, we also documented infection transition between the canopy and bole. Of the 780 live trees that were infected with blister rust in both time-steps, approximately 31% (242) maintained canopy cankers and 36% (281) retained bole infections at the end of the revisit time-step. Infection transition from canopy to bole occurred in 30% (234) of the revisit time-step trees while 3% (23) transitioned from bole to canopy infections during this period. Objective 3. To determine whitebark pine mortality, we resurveyed all belt transects to reassess the life status of permanently tagged trees >1.4 m tall. We compared the total number of live tagged trees recorded during monitoring transect establishment to the total number of resurveyed dead tagged trees recorded during the revisit time-step and identified all potential mortality-influencing conditions (blister rust, mountain pine beetle, fire and other). By the end of the revisit time-step, we observed a total of 975 dead tagged whitebark pine trees; using a ratio estimator, this represents a loss of approximately 20% (SE=4.35%) of the original live tagged tree population (GYWPMWG 2012). Objective 4. To investigate the proportion of live, reproducing tagged trees, we divided the total number of positively identified cone-bearing trees by the total number of live trees in the tagged tree sample at the end of the revisit time-step. To approximate the average density of recruitment trees per stand, trees ≤1.4 m tall were summed by stand (within the 500 m² transect area) and divided by the total number of stands. Reproducing trees made up approximately 24% (996 trees) of the total live tagged population at the end of the revisit time-step. Differentiating between whitebark pine and limber pine seedlings or saplings is problematic given the absence of cones or cone scars. Therefore, understory summaries as presented in this report may include individuals of both species when they are sympatric in a stand. The average density of small trees ≤1.4 m tall was 53 understory trees per 500 m². Raw counts of these understory individuals ranged from 0-635 small trees per belt transect. In addition, a total of 287 trees were added to the tagged tree population by the end of 2011. These newly tagged trees were individuals that upon subsequent revisits had reached a height of >1.4 m tall and subsequently added to the sample. Throughout the past decade in the GYE, monitoring has helped document shifts in whitebark pine forests; whitebark pine stands have been impacted by insect, pathogen, wildland fire, and other disturbance events. Blister rust infection is ubiquitous throughout the ecosystem and infection proportions are variable across the region. And while we have documented mortality of whitebark pine, we have also recorded considerable recruitment. We provide this first step-trend report as a quantifiable baseline for understanding the state of whitebark pine in the GYE. Many aspects of whitebark pine health are highly variable across the range of its distribution in the GYE. Through sustained implementation of the monitoring program, we will continue efforts to document and quantify whitebark pine forest dynamics as they arise under periodic upsurges in insect, pathogen, fire episodes, and climatic events in the GYE. Since its inception, this monitoring program perseveres as one of the only sustained longterm efforts conducted in the GYE with a singular purpose to track the health and status of this prominent keystone species.

Natural Resource Technical Report↗

USGS2006

Efficacy of feral pig removals at Hakalau Forest National Wildlife Refuge

We compiled and analyzed data from 1987–2004 on feral pig ( Sus scrofa ) management and monitoring activities at Hakalau Forest National Wildlife Refuge, a tropical montane rainforest on the island of Hawai`i. These data included annual surveys of feral pig and cattle ( Bos taurus ) activity, the number of feral ungulates removed from closed management units, age and reproductive status from necropsies, and vegetation surveys repeated 4 times over a 16 year period. We found an essentially even sex ratio within the feral pig population and within age classes, although males lived to 60 months while females lived to only 48 months. The pregnancy rate was 23.5%, and lactation rate was 8.3%, regardless of season and age, but lactation peaked in April-June. Reproductive rates also increased with age, peaking at 2–4 years in females. We reconstructed the standing population within a closed unit to examine demographic processes. We estimated that annual removal in excess of approximately 41–43% would be necessary to affect a population decline. We examined annual feral pig activity surveys and found a strong and sustained decline in pig sign after 1997 relative to unmanaged areas. We related the standing population to feral pig activity surveys to build a predictive model of feral pig density, and then applied this model to other management units. We evaluated control methods and found snaring to be more efficient than staff or public hunting. Vegetation monitoring revealed a strong temporal increase in cover of native ferns, and marginally non-significant decreases in cover of bryophytes and exposed soil.

Hawai'i↗

USGS2005

Bird use of reforestation sites: Influence of location and vertical structure

In the Lower Mississippi Valley, more than 300,000 acres of agricultural land have been reforested in the last 10 years. Planning decisions on how and where to restore forest are complex and usually reflect landowner objectives. However, initial planning decisions may have a large influence on the value of restored stands for birds and other wildlife. Reforestation of small, isolated tracts will likely result in mature forests where reproductive output of breeding birds does not compensate for adult mortality (sink habitats). This may be due to factors such as lower reproductive success near edges (edge effects), insufficient area of habitat to attract colonizing birds (area effects), or restricted population mixing and mating opportunities because of limited dispersal among tracts (isolation effects). Conversely, reforestation adjacent to existing forest increases contiguous forest area and provides areas buffered from agricultural or urban habitats (interior forest core). Bottomland reforestation has historically focused on planting relatively slow-growing tree species, particularly oaks (Quercus spp.). Thus, restoration sites are often dominated by grasses and forbs for up to a decade after tree planting. Grassland birds are the first birds to colonize reforested sites. However, abundance and productivity of grassland birds is generally poor on sites associated with woody vegetation, such as sites adjacent to mature forest. As woody vegetation develops on reforested sites, birds preferring shrub-scrub habitat displace grassland species (Twedt et al. 2002) (fig. 1). Planting faster-growing trees compresses the time for colonization by shrub-scrub birds and the increased vertical stature of these trees attracts forest birds (Twedt and Portwood 1996). Additionally, planting next to existing mature forests creates transitional edges that reduce the detrimental effects of abrupt forest-agriculture interfaces.

Technical Note↗

USGS1999

Juvenile Marbled Murrelet nurseries and the productivity index

Late summer counts of juveniles at sea are used as an index of Marbled Murrelet ( Brachyramphus marmoratus ) reproductive success, but little is known about juvenile dispersal or habitat use. Further, it is not known whether these counts accurately reflect absolute breeding success. To address these questions we conducted five boat surveys for Marbled Murrelets and Pigeon Guillemots ( Cepphus columba ) in Kachemak Bay, Alaska between 7-24 August 1996. Juvenile murrelet distribution in the bay was patchy, and we identified a juvenile Marbled Murrelet 'nursery' area in the outer bay. Fifty-three of 61 juvenile murrelets were in this area, whereas after-hatch-year (AHY) murrelets were dispersed throughout the bay, as were juvenile and AHY Pigeon Guillemots. The murrelet nursery was characterized by water inside of or at the edge of a 20 m deep contour, semi-protected seas, productive waters, and a large bed of Nereocystis kelp. Juveniles comprised 16.1% of all murrelets and 24.8% of all guillemots observed at sea. These data suggest a maximum reproductive success of 0.32 chicks/pair if all AHY murrelets were breeding and 0.46 chicks/pair if only 70% of AHY murrelets were breeding. For guillemots, maximum productivity estimated from at-sea counts was 0.50 chicks/pair if all AHY were breeding and 0.71 chicks/pair if only 70% were breeding. The guillemot estimate was similar to that obtained by concurrent studies at nine guillemot colonies in the bay (0.56 chicks/pair). These results suggest that at sea surveys in late summer provide a reasonable index of local productivity for nearshore alcids. Further, if murrelet nursery areas can be found, at sea counts may provide a valid measure of absolute productivity.

Alaska↗

USGS1996

Activity and feeding of ovigerous Dungeness crabs in Glacier Bay, Alaska

The activity and feeding behavior of ovigerous Dungeness crabs, Cancer magister , were examined as part of a long-term study. Part of this study surveyed Bartlett Cove in Glacier Bay, Alaska, during the spring of 1994 where 50 commercial pots were soaked for 24 hours. Catch per unit effort (CPUE), dispersion, and stomach samples of male, nonovigerous female, and ovigerous female crabs were compared. A laboratory experiment compared feeding rate, foraging response, and survival between starved and fed ovigerous and nonovigerous crabs over a six-month winter period (December 1994-May 1995). CPUE differed significantly for crabs of different reproductive groups caught in pots during the spring 1994 survey in Bartlett Cove (ANOVA, P< 0.01). CPUE averaged 3.7 ± 0.5 (standard error) for males, 1.3 ± 0.3 for nonovigerous females, and 0.4 ± 0.1 for ovigerous females. Male and nonovigerous female Dungeness crabs were homogeneously dispersed throughout the pot transect area; however, ovigerous crabs were aggregated. A significant difference in dry weight of stomach contents and stomach fullness between reproductive groups existed. Ovigerous females had significantly lower feeding rates than nonovigerous females in the laboratory (two way ANOVA, P< 0.01). The foraging responses of ovigerous crabs were significantly lower in comparison to nonovigerous females (Mann-Whitney U test, P< 0.01). Seasonal differences were also found for foraging within the two groups over the course of the study period (Kruskal-Wallis one-way ANOVA, P< O.OI). No mortality occurred in treatments of fed and starved ovigerous and nonovigerous crabs over the six-month experiment, demonstrating Dungeness crabs can survive overwinter without feeding in laboratory conditions.

Alaska↗

USGS1995

Nearshore distribution and abundance of Dungeness crabs in Glacier Bay National Park, Alaska

As part of an ongoing, multi-agency study to determine the effects of closure of the commercial fishery for Dungeness crabs, Cancer magister , on crab population structure we examined patterns of distribution and abundance of crabs in nearshore habitats at five locations in and near Glacier Bay National Park. Sampling was conducted in April and September 1992 and April 1993 prior to the anticipated closure of the fishery in the park. Divers censused crabs by sex and reproductive state (ovigerous/nonovigerous females) along belt transects (2m x 100m) laid perpendicular to shore in the depth range 0 m (mean lower low water) to 18 m. Preliminary results from the first three sampling periods revealed that the average densities of Dungeness crabs at the five locations ranged from 78 to 2012 crabs/ha. Crab densities differed between populations depending on sex, reproductive state of females and sampling period. Male crabs showed reduced densities at Gustavus Flats in April 1992 (P<0.01) and 1993 (P<0.001). Ovigerous females had greater density at Bartlett Cove in April 1993 (P<0.001). Sex ratios were frequently skewed toward females. At Bartlett Cove and Gustavus Flats females outnumbered males in April 1992 and 1993 (P<0.001). Most of the females at Bartlett Cove and Gustavus Flats in April 1992 and 1993 were ovigerous (P-0.001). Males tended to occupy greater depths than females in April 1992 (P<0.05) but not April 1993 (P-005). The mean depth of males shifted from deeper to shallower water between April and September 1992 (P<0.001). The depth distribution of ovigerous crabs did not differ from that of nonovigerous female crabs. Future research prior to the anticipated closure of the commercial Dungeness crab fishery in Glacier Bay will include a tagging study to determine the extent of crab movement and further study of the temporal as well as the spatial variability observed in the structure of these populations.

Alaska↗