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At least 307 records · Page 17Linked to original sources
USGS2017

Breeding biology of an endemic Bornean turdid, the Fruithunter (Chlamydochaera jefferyi), and life history comparisons with Turdus species of the world

We present the first description of the breeding biology for the Fruithunter ( Chlamydochaera jefferyi ), a member of the cosmopolitan family Turdidae, and a montane endemic to the tropical Asian island of Borneo. We also compile breeding biology traits from the literature to make comparisons between the Fruithunter and the thrush genus Turdus . Our comparisons indicate that Fruithunters exhibit a slower life history strategy than both tropical and north temperate Turdus . We located and monitored 42 nests in 7 years in Kinabalu Park, Sabah, Malaysia. The mean clutch size was 1.89 ± 0.08 eggs, and the modal clutch size was 2 eggs. Mean fresh egg mass was 6.15 ± 0.13 g, representing 9.5% of adult female body mass. Average lengths of incubation and nestling periods were 14.56 ± 0.24 and 17.83 ± 0.31 days respectively. Only the female incubated and brooded the eggs and nestlings, but both the male and female fed nestlings. Female attentiveness during incubation was high throughout, reaching an asymptote around 85% with average on-bouts of 39.0 ± 2.5 mins. The daily nest survival probability was 0.951 ± 0.025, and the daily predation rate was 0.045 ± 0.024. Female feeding rate increased as brooding effort decreased, suggesting that female feeding rate may be constrained by the need to provide heat while nestlings are unable to thermoregulate. This contrasts with the feeding behavior of males, which showed much less of an increase across the nestling period. Furthermore, we describe a new vocalization which expands the vocal repertoire for Fruithunters, and we provide a brief audio clip and spectrogram.

Wilson Journal of Ornithology↗
USGS2005

Comparative demography of new world populations of thrushes (Turdus spp.): Comment

Survival and fecundity are fundamental to the study of evolutionary ecology, as they are two of the key variables influencing the constrained optimization process we call natural selection. Likewise, population managers require accurate estimates of these parameters; along with dispersal, they govern population dynamics ( Lack 1954 ) and thus are essential for predicting population change and the effects of management actions. It can be frustrating, then, when survival is difficult to estimate for certain populations, as in some avian species that exhibit a substantial degree of dispersal.

Ecology↗
USGS2010

Conserving migratory land birds in the New World: Do we know enough?

Migratory bird needs must be met during four phases of the year: breeding season, fall migration, wintering, and spring migration; thus, management may be needed during all four phases. The bulk of research and management has focused on the breeding season, although several issues remain unsettled, including the spatial extent of habitat influences on fitness and the importance of habitat on the breeding grounds used after breeding. Although detailed investigations have shed light on the ecology and population dynamics of a few avian species, knowledge is sketchy for most species. Replication of comprehensive studies is needed for multiple species across a range of areas. Information deficiencies are even greater during the wintering season, when birds require sites that provide security and food resources needed for survival and developing nutrient reserves for spring migration and, possibly, reproduction. Research is needed on many species simply to identify geographic distributions, wintering sites, habitat use, and basic ecology. Studies are complicated, however, by the mobility of birds and by sexual segregation during winter. Stable-isotope methodology has offered an opportunity to identify linkages between breeding and wintering sites, which facilitates understanding the complete annual cycle of birds. The twice-annual migrations are the poorest-understood events in a bird's life. Migration has always been a risky undertaking, with such anthropogenic features as tall buildings, towers, and wind generators adding to the risk, Species such as woodland specialists migrating through eastern North America have numerous options for pausing during migration to replenish nutrients, but some species depend on limited stopover locations. Research needs for migration include identifying pathways and timetables of migration, quality and distribution of habitats, threats posed by towers and other tall structures, and any bottlenecks for migration. Issues such as human population growth, acid deposition, climate change, and exotic diseases are global concerns with uncertain consequences to migratory birds and even lesscertain remedies. Despite enormous gaps in our understanding of these birds, research, much of it occurring in the past 30 years, has provided sufficient information to make intelligent conservation efforts but needs to expand to handle future challenges. ?? 2010 by the Ecological Society of America.

Ecological Applications↗
USGS2004

Where in the world are my field plots? Using GPS effectively in environmental field studies

Global positioning system (GPS) technology is rapidly replacing tape, compass, and traditional surveying instruments as the preferred tool for estimating the positions of environmental research sites. One important problem, however, is that it can be difficult to estimate the uncertainty of GPS-derived positions. Sources of error include various satellite- and site-related factors, such as forest canopy and topographic obstructions. In a case study from the Hubbard Brook Experimental Forest in New Hampshire, hand-held, mapping-grade GPS receivers generally estimated positions with 1–5 m precision in open, unobstructed settings, and 20–30 m precision under forest canopy. Surveying-grade receivers achieved precisions of 10 cm or less, even in challenging terrain. Users can maximize the quality of their GPS measurements by “mission planning” to take advantage of high-quality satellite conditions. Repeated measurements and simultaneous data collection at multiple points can be used to assess accuracy and precision.

Frontiers in Ecology and the Environment↗
USGS1891

Index to the known fossil insects of the world, including myriapods and arachnids

With the view of furthering study in the too neglected field of fossil insects, I transmit herewith for publication the card catalogue of described fossil insects which I have used for twenty years and kept constantly up to date, and which has greatly facilitated my own researches. It is believed to be practically complete. At least where insects are figured, and in many other cases where they are the first or only references from a given locality, entries are given where only the genus, the family, or even the order is mentioned. This has been done because the early literature of fossil insects is essentially vague and general, but it should not for that reason be wholly overlooked ; and to-day our knowledge of the occurrence of insects of a particular locality, even when of recent discovery, is not infrequently confined to statements of a general nature, which, if not brought to view or mind in a list like this, would be lost sight of, while their recognition may lead to further local investigation, to the earlier benefit of science. It is in no sense a systematic catalogue, and except occasionally in the notes contains no immediate results of investigation. No questions of synonymy are settled. The entries are made as the authors quoted gave them, with only the corrections of spelling required; it follows that the same insect appears at several points, to which the student is referred by full cross-references, and that more than one insect may (though probably rarely does) figure under one name. In one or two such instances, where the same name has been given by inadvertence to two totally different creatures, the later one is separated from the earlier. For convenience' sake, the entries are grouped into large sections, nearly identical with those I have employed in my systematic review of fossil insects (Bulletin 31, U. S. Geological Survey), by which method the insects from the Primary, Secondary, and Tertiary rocks are kept distinct; but otherwise the entries are purely alphabetical under the orders. It should be noticed, however, that the vague references to groups higher than genera are brought together at the beginning of each alphabet, first the most vague, and then those which permit some alphabetization. In these cases the primary or secondary alphabetization is first by authors, second by dates, and in all cases where under one entry there is more than one date the order therein is chronological. In a previous bulletin (Bulletin 69, U. S. Geological Survey) is given a complete bibliography of the literature from which these entries are taken, and the two works are thus complementary to each other.

Bulletin↗
USGS2005

Geography for a Changing World - A science strategy for the geographic research of the U.S. Geological Survey, 2005-2015

This report presents a science strategy for the geographic research of the U.S. Geological Survey (USGS) for the years 2005-2015. The common thread running through the vision, mission, and science goals presented in the plan is that USGS geographers will provide national leadership to understand coupled human-environmental systems in the face of land change and will deliver pertinent information to decisionmakers on the vulnerability and resilience of these systems. We define land change science as the study of the human and environment dynamics that give rise to changed land use, cover, and surface form. A number of realities shape the strategic context of this plan: The Department of Interior Strategic Plan focuses on meeting society’s resource needs and sustaining the Nation’s life support systems, underscoring the importance of characterizing and understanding coupled human-environmental systems. In redefining its mission in the mid-1990s, the USGS envisions itself as an integrated natural science and information agency. The USGS will assume a national leadership role in the use of science to develop knowledge about the web of relations that couple biophysical and human systems and translate this knowledge into unbiased, reliable information that meets important societal information needs. The following trends will influence USGS geography-oriented science activities over the next decade. Most of the emerging earth science issues that the USGS will address are geographic phenomena. A growing international concern for aligning society’s development activities with environmental limits has led to an articulation of a science agenda associated with global environmental change, vulnerability, and resilience. Earth science investigations have evolved toward the study of very large areas, and the resulting huge volumes of data are challenging to manage and understand. Finally, scientists and the public face the challenge of gaining intelligent insights about geographic and environmental processes from these data, with the ultimate goal of guiding resource-management decisions. The first four science goals in the plan support understanding the human and environmental dynamics of land change. Each science goal has an associated set of strategic actions to achieve the goal. These goals and actions are consistent with national science priorities and the Department of Interior and USGS missions, take advantage of existing expertise, and lead to the strengthening of critical geographic research capacities that do not exist in other USGS disciplines.

Circular↗