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At least 919 records · Page 51Linked to original sources

Arthropod community structure on bark of koa ( Acacia koa ) and ʻōhiʻā ( Metrosideros polymorpha ) at Hakalau Forest National Wildlife Refuge, Hawaiʻi Island, Hawaiʻi

The arthropod community associated with tree bark contains a wide variety of taxa but is poorly described, particularly in Hawaiʽi. Our overall goals were to evaluate the abundance of arthropods available to foraging birds and how variation in bark substrates may contribute to arthropod distributions in native forests. Our study aimed to identify this fauna on the dominant canopy-forming trees koa ( Acacia koa ) and ʽōhiʽa ( Metrosideros polymorpha ) within wet montane forest at Hakalau Forest National Wildlife Refuge, Hawaiʽi Island. At two sites roughly similar in elevation and habitat structure, we deployed three trap types designed to intercept arthropods moving along bark within tree canopies: a bole trap based on a pre-existing design and two traps specially designed for this study. Bole traps were placed on koa and ʽōhiʽa while branch traps were established on large and small branches of ʽōhiʽa. In total, 15 arthropod orders were identified, with Collembola most abundant (number/trap-day) generally followed by Isopoda and Araneae. Differences in abundance were found in some instances, but overall, few differences were detected between tree species or sites. Relative abundances of arthropod groups were also generally similar between trees and sites and among different parts of ʽōhiʽa. These results indicate that bark-dwelling arthropod communities are similar on koa and ʽōhiʽa, and birds should not develop strong preferences for gleaning arthropods from the bark of either species of tree based on prey availability.

Hawai'i↗

Quantitative wildlife habitat evaluation using high-altitude color infrared aerial photographs

The habitat value for elk and sage grouse of two proposed phosphate strip mine sites was determined using habitat parameter measurements from high-altitude color infrared aerial photographs. Habitat suitability was assessed using the Habitat Evaluation Procedures being developed by the U.S. Fish and Wildlife Service. Similar results were obtained from two approaches--a remote-sensing-only approach and a mix of measurements from photo interpretation and conventional field surveys.

Conference Paper↗

Fish and wildlife mitigation options for port development in Tampa Bay: results of a workshop

This report records the results of a workshop held September 25-27, 1983, in Tampa, Florida. The organization of the report closely follows the organization of the workshop itself. The workshop began with a definition of objectives and several presentations providing general background. The context and objectives of the workshop are covered in the INTRODUCTION. A summary of the results of two group discussions is presented in the WORKSHOP RESULTS section. One group identified ways to conduct or locate port development activities in Tampa Bay so as to lessen their adverse impacts; the other group identified ways to compensate for unavoidable impacts by creating or improving important fish and wildlife habitats. Finally, the DISCUSSION section contains the authors' synthesis of more general comments made throughout the workshop, especially during the closing session.

Florida↗

Prevalence of the amphibian chytrid fungus (Batrachochytrium dendrobatidis) at Buenos Aires National Wildlife Refuge, Arizona, USA

Information on disease presence can be of use to natural resource managers, especially in areas supporting threatened and endangered species that occur coincidentally with species that are suspected vectors for disease. Ad hoc reports may be of limited utility (Muths et al. 2009), but a general sense of pathogen presence (or absence) can inform management directed at T&E species, especially in regions where disease is suspected to have caused population declines (Bradley et al. 2002). The Chiricahua Leopard Frog (Lithobates chiricahuensis), a species susceptible to infection by the amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) (Bradley et al. 2002), and the non-native, invasive American Bullfrog (L. catesbeianus), a suspected vector for chytridiomycosis (Schloegel et al. 2012, Gervasi et al. 2013), both occur at Buenos Aires National Wildlife Refuge (BANWR) and surrounding lands in southern Arizona. Efforts to eradicate the bullfrog from BANWR began in 1997 (Suhre, 2010). Eradication from the southern portion of BANWR was successful by 2008 but the bullfrog remains present at the Arivaca Cienega and in areas immediately adjacent to the refuge (Fig. 1). Curtailing the re-invasion of the bullfrog into BANWR will require vigilance as to ensure the health of Chiricahua Leopard Frog populations.

Arizona↗

Vegetation mapping of Nowitna National Wildlife Refuge, Alaska using Landsat MSS digital data

A Landsat-derived vegetation map was prepared for Nowitna National Wildlife Refuge. The refuge lies within the middle boreal subzone of north central Alaska. Seven major vegetation classes and sixteen subclasses were recognized: forest (closed needleleaf, open needleleaf, needleleaf woodland, mixed, and broadleaf); broadleaf scrub (lowland, alluvial, subalpine); dwarf scrub (prostrate dwarf shrub tundra, dwarf shrub-graminoid tussock peatland); herbaceous (graminoid bog, marsh and meadow); scarcely vegetated areas (scarcely vegetated scree and floodplain); water (clear, turbid); and other areas (mountain shadow). The methodology employed a cluster-block technique. Sample areas were described based on a combination of helicopter-ground survey, aerial photointerpretation, and digital Landsat data. Major steps in the Landsat analysis involved preprocessing (geometric correction), derivation of statistical parameters for spectral classes, spectral class labeling of sample areas, preliminary classification of the entire study area using a maximum-likelihood algorithm, and final classification utilizing ancillary information such as digital elevation data. The final product is a 1:250,000-scale vegetation map representative of distinctive regional patterns and suitable for use in comprehensive conservation planning.

Alaska↗

Intermediate-scale vegetation mapping of Innoko National Wildlife Refuge, Alaska using Landsat MSS digital data

A Landsat-derived vegetation map was prepared for lnnoko National Wildlife Refuge. The refuge lies within the northern boreal subzone of northwestern central Alaska. Six major vegetation classes and 21 subclasses were recognized: forest (closed needleleaf, open needleleaf, needleleaf woodland, mixed, and broadleaf); broadleaf scrub (lowland, upland burn regeneration, subalpine); dwarf scrub (prostrate dwarf shrub tundra, erect dwarf shrub heath, dwarf shrub-graminoid peatland, dwarf shrub-graminoid tussock peatland, dwarf shrub raised bog with scattered trees, dwarf shrub-graminoid marsh); herbaceous (graminoid bog, graminoid marsh, graminoid tussock-dwarf shrub peatland); scarcely vegetated areas (scarcely vegetated scree and floodplain); and water (clear, sedimented). The methodology employed a cluster-block technique. Sample areas were described based on a combination of helicopter-ground survey, aerial photo-interpretation, and digital Landsat data. Major steps in the Landsat analysis involved preprocessing (geometric correction), derivation of statistical parameters for spectral classes, spectral class labeling of sample areas, preliminary classification of the entire study area using a maximum-likelihood algorithm, and final classification utilizing ancillary information such as digital elevation data. The final product is 1:250,000-scale vegetation map representative of distinctive regional patterns and suitable for use in comprehensive conservation planning.

Alaska↗

Vegetation and non-native ungulate monitoring at the Big Island National Wildlife Refuge Complex 2010–2014.

The Hakalau Forest Unit (HFU) of Big Island National Wildlife Refuge Complex (BINWRC) has intensively managed feral cattle (Bos taurus) and pigs (Sus scrofa) and monitored non-native ungulate presence and distribution during surveys of all managed areas since 1988. We: 1) provide results from recent ungulate surveys at HFU to determine current feral pig abundance and distribution; 2) present results of surveys of ungulate presence and distribution at the Kona Forest Unit (KFU); 3) present results of surveys of weed presence and cover at both refuge units; and 4) present baseline results from long-term vegetation monitoring plots at KFU. Overall pig abundance appears to have decreased at HFU, although not significantly, over the period from 2010 to 2014. Management units 2 and 4 contained the majority of pigs at HFU. Pig density outside of adjacent managed areas has declined significantly from 2010 to 2014 for unknown reasons. Ungulate sign occurred in > 50% of plots at KFU during the November 2012 and September 2013 surveys, but ungulate sign occurred in < 28% of plots during three other surveys. The ability to differentiate sign of ungulate species remains problematic at KFU. Changes in weed cover do not yet demonstrate any strong temporal pattern. Spatial patterns are more pronounced; however, some weed species may not be reliably represented due to observers&rsquo; abilities to recognize less common weeds. Nonetheless, the distribution and cover of fireweed (Senecio madagascariensis) at KFU may have increased over the study period. Vegetation surveys documented baseline floristic composition and forest structure at KFU. It is not known if this current amount of emerging cover is sufficient for long-term self-sustaining forest canopy regeneration; however, numerous &lsquo;ōhi&lsquo;a seedlings were found in the wet forest and mesic &lsquo;ōhi&lsquo;a habitats, indicating an ample viable seed source and robust potential for forest regeneration.

Hawaii↗

Dynamics and ecological consequences of the 2013−2014 koa moth outbreak at Hakalau Forest National Wildlife Refuge.

A massive outbreak of the koa moth (Geometridea: Scotorythra paludicola) defoliated more than a third of the koa (Acacia koa) forest on Hawai&lsquo;i Island during 2013&minus;2014. This was the largest koa moth outbreak ever recorded and the first on the island since 1953. The outbreak spread to sites distributed widely around the island between 800&minus;2,000 m elevation and in wet rainforest to dry woodland habitats. We monitored the outbreak at two windward forest sites (Laupāhoehoe and Saddle Road Kīpuka) and one leeward forest site (Kona), and we studied the dynamics of the outbreak and its impacts on the forest ecosystem at Hakalau Forest National Wildlife Refuge, our higher elevation windward site. Study sites at Hakalau included two stands of koa that were planted (reforestation stands) in former cattle pastureland about 20 years earlier and two stands of koa that were dominated by &lsquo;ōhi&lsquo;a (Metrosideros polymorpha) and that were naturally recovering from cattle grazing (forest stands). We observed one outbreak at Hakalau, multiple outbreaks at the two other windward sites, but no outbreak at the leeward site. Caterpillars at Hakalau reached peak estimated abundances of more than 250,000 per tree and 18,000,000 per hectare, and they removed between 64&minus;93% of the koa canopy in managed forest stands. Defoliation was more extensive in naturally recovering forest, where &lsquo;ōhi&lsquo;a dominated and koa was less abundant, compared to the planted stands, where koa density was high. Koa trees were still growing new foliage six months after being defoliated, and leaves were produced in greater proportion to phyllodes, especially by small koa (&le; 8 cm dbh) and by larger trees in forest stands, where light levels may have remained relatively low after defoliation due to the high cover of &lsquo;ōhi&lsquo;a. Small branches of many trees apparently died, and canopy regrowth was absent or low in 9% of koa trees and seedlings, which indicates the likely level of mortality. Between 2,000&minus;5,000 kg/ha of frass fell during the defoliation event, resulting in the deposition of up to 200 kg/ha of highly labile nitrogen on the forest floor in less than two months. The deposition of nitrogen was detected as pulses in resin-available nitrogen in the top 5&minus;10 cm of soil at two of three sites. These sites showed elevated soil nitrogen for about seven months. Nitrogen content of understory plant foliage, which is indicative of nitrogen uptake, suggested weak and variable effects of nitrogen deposition in the soil. Foliar nitrogen increased slightly in alien pasture grasses four months after the deposition of frass, although distinctive increases were not detected in native woody species. Birds responded to the abundance of caterpillars by increasing their activity in koa during the buildup of caterpillars and decreasing their use of koa after defoliation. During the outbreak, caterpillars increased in the diets of the two generalist insectivores we examined, and nearly all species gained weight. Bats responded to the abundance of moths by compression of active foraging into the first three hours of darkness each night after presumably having reached a digestive bottleneck. Reduced foraging activity by bats also resulted in lower indices of detectability based upon acoustic monitoring when compared to non-outbreak years. Parasitoid wasps tracked caterpillar abundance, but the low rate at which they attacked caterpillars suggests that they had little influence on the population. The predatory yellowjacket (Vespula pensylvanica) did not respond to the outbreak. Although a single, protracted outbreak occurred at Hakalau, multiple outbreaks and defoliations occurred at lower elevations. Our results provide a broad foundation for evaluating the dynamics and impacts of future Scotorythra outbreaks.

Hawaii↗

Mammals of Red Slough Wildlife Management Area, with comments on McCurtain County, Oklahoma

Red Slough Wildlife Management Area (RSWMA) is located in the southeastern corner of Oklahoma, McCurtain County, and represents the extreme northwestern extent of the South Central Plains (SCP) ecoregion. Previous mammal research in southeastern Oklahoma has focused mostly on the Ouachita Mountains to the north of RSWMA. As a result, of the 69 species of mammals potentially occurring in McCurtain County, only 48 species represented by 599 voucher specimens reside in natural history collections. We present results from a mammal survey of RSWMA conducted from December 2009 to August 2010. We captured 574 non-volant small mammals in 9,115 trap-nights, 11 bats in 17 net-nights, and seven salvaged meso-mammals resulting in 157 voucher specimens of 22 mammal species, including the first specimen of Castor canadensis for McCurtain County, and photographic vouchers for eight additional species from RSWMA. These results provide a baseline for future studies on RSWMA and substantially increase our natural history knowledge for many relatively under-studied mammals in southeastern Oklahoma

Oklahoma↗

Effects of migratory waterfowl on water quality at the Montezuma National Wildlife Refuge, Seneca County, New York

This study was done in response to the shellfish industry's concern that bacteria in effluent from the national wildlife refuges along the northeast coast of the United States may be adversely affecting the harvest of shellfish. A line graph shows inconsistent relationships between bird population at the Montezuma refuge and total coliform, fecal coliform, and fecal Streptococci counts. Salmonella were found in only one of 17 samples of water taken within the refuge. Counts of nonpathogenic bacteria in the two major streams flowing into the refuge, Black Brook and White Brook, were greater than they were in water flowing out of the refuge. Specific conductance of water flowing out of the refuge was less than that of water flowing into the refuge, although the effluent had higher concentrations of phosphorus and nitrogen than the influent. A settling-pond effect in the quiet water of the refuge may help explain the improvement in the quality of the water leaving the refuge. The study shows how its quality changes both chemically and biologically as water flows through the refuge. Further study is needed, however, to determine the effects that a similar effluent would have on a coastal habitat of shellfish.

New York↗

Abundance, distribution, and removals of feral pigs at Big Island National Wildlife Refuge Complex 2010–2015

The Hakalau Forest Unit (HFU) of Big Island National Wildlife Refuge Complex (BINWRC) has intensively monitored non-native ungulate presence and distribution during surveys of all managed areas since 1988. In this report we: 1) provide results from recent ungulate surveys and the number of removals at HFU to determine the distribution, abundance, and efficacy of removals of feral pigs, the dominant ungulate, from 2010 to 2015; 2) present results of surveys of the presence and distribution of several ungulate species at the Kona Forest Unit (KFU) of BINWRC from November of 2012 to April of 2015; 3) present results of surveys of weed presence and cover at both refuge units; and 4) present comparative analyses of forest canopy cover at KFU from visual estimates and geospatial imagery. Removals of feral pigs at HFU appear to have significantly decreased pig abundance over the study period from 2010&ndash;2015. A grand total of 1,660 feral pigs were removed from managed areas of HFU from 2010 until September of 2015. Management units 2 and 4 contained the majority of pigs at HFU. Recent surveys recorded high densities of pigs in the unenclosed, unmanaged area of Lower Maulua, reaching 14.9 &plusmn; (3.2) pigs/km 2 in March of 2015. The total amount of ungulate sign ranged from 22.2 to 54.3 percent of plots surveyed at KFU from November of 2012 to April of 2015. The ability to differentiate sign of ungulate species remains problematic at KFU; although there appears to have been a significant decline in feral cattle sign at KFU, this result is likely to be unreliable because cattle and pig sign were not differentiated consistently during later surveys. Spatial distributions in weed cover are distinctive; however, some weed species may not be reliably represented due to observers&rsquo; inconsistencies in recording data and abilities to recognize less common weeds.

Hawaii↗

Passerine bird trends at Hakalau Forest National Wildlife Refuge, Hawai‘i

Hakalau Forest National Wildlife Refuge, on the Island of Hawai&lsquo;i, was established in 1985 to protect native forest birds, particularly endangered species. Management actions on the 15,400 ha refuge include removing feral ungulates from the forest and pastures, controlling invasive alien plants, reforesting pastures, and supplementing endangered plant populations. To assess effects of this habitat improvement for birds, we calculated annual density estimates from point transect surveys and examined population trends for eight native and four alien passerine bird species over the 21 years since the refuge was established (1987-2007). We examined trends using a Bayesian approach to log-linear regression. We tested for changes in bird density in three study areas: (1) a middle elevation forest that had been heavily grazed, (2) an upper elevation pasture that was reforested during the study, and (3) a lower area of relatively intact forest that was formerly lightly grazed. In the middle study area, we found that densities of Hawai&lsquo;i &lsquo;Elepaio (Chasiempis s. sandwichensis), and the endangered &lsquo;Akiapōlā&lsquo;au (Hemignathus munroi) and Hawai&lsquo;i Creeper (Oreomystis mana) increased, and that all other native birds showed stable trends and exhibited no evidence of declining trends as has been seen elsewhere in much of Hawai&lsquo;i. Trends for all alien birds were also stable, except that House Finch (Carpodacus mexicanus) density has declined. In the lower study area, Hawai&lsquo;i Creeper and Hawai&lsquo;i &lsquo;Ākepa (Loxops c. coccineus) showed increasing trajectories, and densities have declined for the other native species. Within the reforested upper study area, densities increased for three common native species&mdash;Hawai&lsquo;i &lsquo;Amakihi (Hemignathus virens), &lsquo;I&lsquo;iwi (Vestiaria coccinea), and &lsquo;Apapane (Himatione sanguinea)&mdash;and two alien species&mdash;Japanese White-eye (Zosterops japonicus) and House Finch. Bird trends at the Hakalau refuge provide some of the first results of habitat improvement for forest birds in Hawai&lsquo;i. Restoring tree cover in open pasture and assisting recovery of high-quality habitat benefits both endangered and abundant native birds

Hawai'i↗

Changes in the prevalence of avian disease and mosquito vectors at Hakalau Forest National Wildlife Refuge: a 14-year perspective and assessment of future risk

Throughout the main Hawaiian Islands, introduced mosquito-borne disease has had, and continues to have, a profound impact on the distributions and abundance of native Hawaiian forest birds. Populations of remaining native forest birds are largely restricted to high elevation forests where mean temperatures are marginal for vector and parasite development and limited availability of larval mosquito habitat constrains mosquito populations and disease transmission. Hakalau Forest National Wildlife Refuge (HFNWR) was established for the preservation of endemic avifauna in 1985. Since its creation, native bird communities there have remained intact and most species populations are stable or increasing. However, avian malaria had been detected at HFNWR in the past and, in light of documented climate change, new concerns have been raised regarding the long-term fate of the refuge&rsquo;s forest birds. To examine the possible changes in avian malaria transmission at HFNWR we sampled forest birds for blood parasites, trapped adult mosquitoes and surveyed larval mosquito habitat at three sites during 2012 and compared our results with similar data collected between 1998 and 1999. We tested blood samples by polymerase chain reaction (PCR), immunoblotting, and microscopy to determine prevalence of acute and chronic infection and used attractive gravid traps to sample the vector mosquito Culex quinquefasciatus. Our study documented spatial trends and temporal changes in the prevalence of avian malaria, mosquito presence, larval mosquito habitat and feral pig activity at HFNWR. We found evidence of local transmission in high elevation forests, a general pattern of increasing prevalence at lower elevations and along a South to North gradient and a two-fold decrease in the prevalence of avian malaria in the intervening 14 years. Despite considerable effort, we were unable to detect larval C. quinquefasciatus and captured only one adult indicating that the vector of avian malaria has a very limited presence at HFNWR. We did, however, document the establishment of another invasive mosquito, Aedes japonicus japonicus , and its occurrence in tree fern cavities and rock pools as larval habitat in the lower forests of HFNWR. We suggest that interspecific competition by A. j. japonicus and predation by a suite of native predators may provide biotic resistance to the establishment of permanent C. quinquefasciatus populations. While current predictions of climate change in the Hawaiian Islands include a gradual warming and enhanced transmission by mid-century, the current cooling trend recorded at high elevation HFNWR illustrates the importance of monitoring to document fine scale temporal and site specific changes in prevalence. Long term changes in precipitation may have a more profound effect on local transmission of malaria than temperature and we may have already seen some potential impacts of an extended drought at HFNWR with a decrease in feral pig activity and pig associated larval mosquito habitat and increases in stream-associated larval mosquito habitat.

Hawaii↗

Federal collaboration in science for invasive mammal management in U.S. National Parks and Wildlife Refuges of the Pacific Islands

Some of the most isolated islands in the Pacific Ocean are home to US National Parks and Wildlife Refuges. These islands are known for flora and fauna that occur nowhere else, but also for invasive species and other factors which have resulted in the disproportionate extinction of native species. The control of invasive mammals is the single most expensive natural resource management activity essential for restoring ecological integrity to parks in the Hawaiian Islands, American Samoa, and the islands of Guam and Saipan. Science-based applications supporting management efforts have been shaped by longstanding collaborative federal research programs over the past four decades. Consequently, feral goats (Capra hircus) have been removed from >690 km2 in National Parks, and feral pigs (Sus scrofa) have been removed from >367 km2 of federal lands of Hawai‘i, bringing about the gradual recovery of forest ecosystems. The exclusion of other non-native ungulates and invasive mammals is now being undertaken with more sophisticated control techniques and fences. New fence designs are now capable of excluding feral cats (Felis catus) from large areas to protect endangered native waterfowl and nesting seabirds. Rodenticides which have been tested and registered for hand and aerial broadcast in Hawai‘i have been used to eradicate rats from small offshore islands to protect nesting seabirds and are now being applied to montane environments of larger islands to protect forest birds. Forward-looking infrared radar (FLIR) is also being applied to locate wild ungulates which were more recently introduced to some islands. All invasive mammals have been eradicated from some remote small islands, and it may soon be possible to manage areas on larger islands to be free of invasive mammals at least during seasonally important periods for native species.

Conference Paper↗

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↗

Monitoring and assessment of juvenile steelhead on Toppenish National Wildlife Refuge. Quick Response Project for 2001

Toppenish National Wildlife Refuge (TNWR) in south central Washington was established in 1964 to provide an important link in the chain of feeding and resting areas for waterfowl and other migratory birds using the Pacific Flyway. Wetlands on TNWR include both natural floodplain wetlands along Toppenish Creek and man-made impoundments designed to mimic natural floodplain processes. Wetland improvement projects were completed between 1995-1998 to restore wetland habitat conditions and eliminate monotypic stands of invasive reed canary grass. Habitat improvements boosted fall/winter use from 2,000 to 50,000 waterfowl, and increased overall use by many species of water birds, shorebirds, and other migratory birds. Increased use by bald eagles, peregrine falcons, and willow flycatchers has also been recorded.

Washington↗

Extracting temporal and spatial information from remotely sensed data for mapping wildlife habitat: Tucson

The research accomplished in this dissertation used both mathematical and statistical techniques to extract and evaluate measures of landscape temporal dynamics and spatial structure from remotely sensed data for the purpose of mapping wildlife habitat . By coupling the landscape measures gleaned from the remotely sensed data with various sets of animal sightings and population data , effective models of habitat preference were created. Measures of temporal dynamics of vegetation greenness as measured by National Oceanographic and Atmospheric Administration’s Advanced Very High Resolution Radiometer (AVHRR) satellite were used to effectively characterize and map season specific habitat of the Sonoran pronghorn antelope, as well as produce preliminary models of potential yellow-billed cuckoo habitat in Arizona. Various measures that capture different aspects of the temporal dynamics of the landscape were derived from AVHRR Normalized Difference Vegetation Index composite data using three main classes of calculations: basic statistics, standardized principal components analysis, and Fourier analysis. Pronghorn habitat models based on the AVHRR measures correspond visually and statistically to GIS-based models produced using data that represent detailed knowledge of ground-condition. Measures of temporal dynamics also revealed statistically significant correlations with annual estimates of elk population in selected Arizona Game Management Units, suggesting elk respond to regional environmental changes that can be measured using satellite data . Such relationships, once verified and established, can be used to help indirectly monitor the population. Measures of landscape spatial structure derived from IKONOS high spatial resolution (1-m) satellite data using geostatistics effectively map details of Sonoran pronghorn antelope habitat . Local estimates of the nugget, sill, and range variogram parameters calculated within 25 x 25-meter image windows describe the spatial autocorrelation of the image, permitting classification of all pixels into coherent units whose signature graphs exhibit a classic variogram shape. The variogram parameters captured in these signatures have been shown in previous studies to discriminate between different species-specific vegetation associations. The synoptic view of the landscape provided by satellite data can inform resource management efforts. The ability to characterize the spatial structure and temporal dynamics of habitat using repeatable remote sensing data allows closer monitoring of the relationship between a species and its landscape.

Arizona↗

Satellite telemetry: A new tool for wildlife research and management

The U.S. Fish and Wildlife Service and the Alaska Department of Fish and Game have cooperated since 1984 to develop and evaluate satellite telemetry as a means of overcoming the high costs and logistical problems of conventional VHF (very high frequency) radiotelemetry systems. Detailed locational and behavioral data on caribou ( Rangifer tarandus ), polar bears ( Ursus maritimus ), and other large mammals in Alaska have been obtained using the Argos Data Collection and Location System (DCLS). The Argos system, a cooperative project of the Centre National d'Études Spatiales of France, the National Oceanic and Atmospheric Administration, and the National Aeronautics and Space Administration, is designed to acquire environmental data on a routine basis from anywhere on earth. Transmitters weighing 1.6-2.0 kg and functioning approximately 12-18 months operated on a frequency of 401.650 MHz. Signals from the transmitters were received by Argos DCLS instruments aboard two Tiros-N weather satellites in sun-synchronous, nearpolar orbits. Data from the satellites were received at tracking stations, transferred to processing centers in Maryland and France, and made available to users via computer tape, printouts, or telephone links. During 1985 and 1986, more than 25,000 locations and an additional 28,000 sets of sensor data (transmitter temperature and short-term and long-term indices of animal activity) were acquired for caribou and polar bears. Locations were calculated from the Doppler shift in the transmitted signal as the satellite approached and then moved away from the transmitter. The mean locational error for transmitters at known locations (n - 1,265) was 829 m; 90% of the calculated locations were within 1,700 m of the true location. Caribou transmitters provided a mean of 3.1 (+5.0. SD) locations per day during 6h of daily operation, and polar bear transmitters provided 1.7 (+6.9SD) locations during 12h of operation every third day. During the first 6 months of operation, the UHF (ultra-high frequency) signal failed on three of 32 caribou transmitters and 10 of 36 polar bear transmitters. A geographic information system (GIS) incorporating other databases (e.g., land cover, elevation, slope, aspect, hydrology, ice distribution) was used to analyze and display detailed locational and behavioral data collected via satellite. Examples of GIS applications to research projects using satellite telemetry and examples of detailed movement patterns of caribou and polar bears are presented. This report includes documentation for computer software packages for processing Argos data and presents developments, as of March 1987, in transmitter design, data retrieval using a local user terminal, computer software, and sensor development and calibration.

Resource Publication↗