There is a special reason for reviewing this book at this time: it is the 50th edition of a compendium that is known and used frequently in most chemical and physical laboratories in many parts of the world. Surely, a publication that has been published for 56 years, withstanding the vagaries of science in this century, must have had something to offer. There is another reason: while the book is a standard fixture in most chemical and physical laboratories, including those in medical centers, it is not as frequently seen in the laboratories of physician's offices (those either in solo or group practice). I believe that the Handbook can be useful in those laboratories. One of the reasons, among others, is that the various basic items of information it offers may be helpful in new tests, either physical or chemical, which are continuously being published. The basic information may relate

Handbook of Chemistry and Physics

Bones of recent mammals in the Amboseli Basin, southern Kenya, exhibit distinctive weathering characteristics that can be related to the time since death and to the local conditions of temperature, humidity and soil chemistry. A categorization of weathering characteristics into six stages, recognizable on descriptive criteria, provides a basis for investigation of weathering rates and processes. The time necessary to achieve each successive weathering stage has been calibrated using known-age carcasses. Most bones decompose beyond recognition in 10 to 15 yr. Bones of animals under 100 kg and juveniles appear to weather more rapidly than bones of large animals or adults. Small-scale rather than widespread environmental factors seem to have greatest influence on weathering characteristics and rates. Bone weathering is potentially valuable as evidence for the period of time represented in recent or fossil bone assemblages, in- cluding those on archeological sites, and may also be an important tool in censusing populations of animals in modern ecosystems.

Taphonomic and Ecologic Information Form Bone Weathering

The Study of Instinct

While the impacts of high exploitation on fish populations and aquatic ecosystems are well-documented for commercial fishing, particularly in the marine environment, the potential biological impacts of angling received less attention. This paper discusses angling patterns within a framework of basic ecological and evolutionary literature and examines potential biological impacts of angling by focusing on study results associated with high exploitation rates and pronounced selective exploitation. The impacts range from impacts occurring directly on the exploited species (truncation of the natural age and size structure, depensatory mechanisms, loss of genetic variability, evolutionary changes), to those that occur on the aquatic ecosystem (changes in trophic cascades, trait-mediated effects). As a third category, impacts related to the angling activity per se are distinguished (habitat modifications, wildlife disturbance, nutrient inputs, loss of fishing gear). Although the main threats to fish often are l...

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Documented and Potential Biological Impacts of Recreational Fishing: Insights for Management and Conservation

Oceanic Birds of South America

EVANS, R. M. 1970. Parental recognition and the "mew call" in Black-billed gulls (Larus bulleri). Auk 87:503-513. HAARTMAN, L. vON. 1953. Was reizt den Trauerfliegenschnapper (Muscicapa hypoleuca) zu futtern? Die Vogelwarte 16:157-164. IMPEKOVEN, M. 1971. Calls of very young Blackheaded gull chicks under different motivational states. Ibis 113:91-96. NORTON-GRIFFITHS, M. 1969. The organization, control, and development of parental feeding in the Oystercatcher (Haematopus ostralegus). Behaviour 24:57-114. TINBERGEN, N. 1953. The Herring Gull's world. Collins, London. VERMEER, K. 1963. The breeding ecology of the Glaucous-winged Gull (Larus glaucescens) on Mandarte Island, B.C. Occ. Pap. British Columbia Prov. Mus. 13:1-104. WARD, J. 1973. Reproductive success, food supply, and the evolution of clutch size in the Glaucouswinged gull. Ph.D. Diss., Univ. British Columbia.

Effects of Human Activity on Egg and Chick Mortality in a Glaucous-Winged Gull Colony

Eggshell taphonomy often is acknowledged to be worthy of investigation, but few studies have examined factors influencing eggshell preservation. In this study eggshell weathering, fragmentation, dispersal, orientation, and predation were characterized in field and laboratory studies. Modern gull eggshell fragment dispersal and orientation patterns were compared with analogous patterns at a non-avian dinosaur egg clutch site. Among other findings: (1) hatched and depredated gull eggshells protected by an exclosure, but exposed to two years of colony weathering, fragmented relatively slowly, suggesting that colony resident activity is responsible for the relatively rapid disappearance of eggshell on the colony surface; (2) depredated eggshells could be distinguished from hatched eggshells due, in part, to differences in fracture patterns; (3) both gull and non-avian dinosaur eggshell fragments were most abundant close to nest centers, whereas this was not true for bones and mollusc shells in gull t...

https://www.jstor.org/stable/info/3515541

Eggshell Taphonomy at Modern Gull Colonies and a Dinosaur Clutch Site

Summary


1
It was once assumed that commercially important fish make up significant portions of seal diets. As a consequence, prior to the 1970s many seal populations were dramatically reduced by rampant slaughtering. Today, seals and other marine mammals are valued components of marine ecosystems and their numbers are carefully managed. To facilitate management, government statutes mandate the systematic monitoring of seal populations. Population estimates are based on counts of hauled-out seals obtained by aerial survey and radio and satellite telemetry; hence, considerable effort has been devoted to finding optimal times for such counts. We have developed a predictive mathematical model of seal haul-out to assist resource managers in the selection of optimal census times.

2
Haul-out depends on a number of environmental variables. Some of these variables, such as wind speed, can be obtained only as historical data or short-range predictions. Others, such as tide height, are deterministic and can be obtained as long-range predictions.

3
We used deterministic environmental variables to develop mathematical models that describe haul-out dynamics of harbour seals Phoca vitulina during the pupping season at a site in Washington, USA. A list of alternative hypotheses for environmental cues gave rise to a suite of competing models. We used information–theoretic model selection techniques to choose the best model. The selected model was a function of tide height and current direction, and explained 40% of the variability in hourly census data.

4
An assumption that the system recovers rapidly after disturbance introduced two time scales. This allowed the differential equation model to be reduced to an algebraic equation.

5
Synthesis and applications. This study demonstrates that resource managers can use a simple algebraic equation based on deterministic environmental variables to predict times at which to census maximal haul-out in harbour seals. At the Washington site, maximal daily haul-outs during pupping season are predicted to occur during receding tides, approximately midway between high and low tides. The largest maximal daily haul-outs during the pupping season are predicted to occur in the last week of July. The environmental factors correlated with haul-out are, however, site-specific; therefore the model developed for the Washington site will not necessarily hold for other haul-out areas. Managers should carry out the model selection procedure separately for each monitored haul-out site. The general methodology employed in this study can be used to make long-range predictions of diurnal movements for a variety of marine birds and mammals.

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Predicting numbers of hauled‐out harbour seals: a mathematical model

Cannibalism occurs regularly across a broad range of taxa with a variety of ecological and evolutionary consequences. Rises in sea surface temperature (SST) have been linked to increased cannibalism in some species, including polar bears (Ursus maritimus), Peruvian anchovy (Engraulis ringens), and Peruvian hake (Merluccius gayi peruanus), and might be expected in birds that depend on marine food webs for sustenance. Increased SSTs are associated with lowered ocean thermoclines and weakened upwellings. These changes, in turn, lead to decreased productivity in surface water and movement of surviving forage fish to deeper water, thereby food-stressing surface feeders such as gulls, diminishing energy intake and lengthening foraging bouts. While controlling for a suite of other environmental factors, we tested whether egg cannibalism and hatching success were independent of rises in local SST at a colony of Glaucous-winged Gulls (Larus glaucescens) and Glaucous-winged × Western Gull (L. glaucescens ×...

/pdf/egg-cannibalism-in-a-gull-colony-increases-with-sea-surface-24fqdpmtna.pdf

Egg cannibalism in a gull colony increases with sea surface temperature

Dinosaur eggshell is abundant in the fossil record but only during the last several decades has this reproductive product been considered more than a novelty. Recent work has provided evidence that...

James L. Hayward

Papers

Effects of Human Activity on Egg and Chick Mortality in a Glaucous-Winged Gull Colony

Eggshell Taphonomy at Modern Gull Colonies and a Dinosaur Clutch Site

Predicting numbers of hauled‐out harbour seals: a mathematical model

Egg cannibalism in a gull colony increases with sea surface temperature

Eggshell taphonomy: environmental effects on fragment orientation