Fitness consequences of pre- and post-fledging timing decisions in a double-brooded passerine

The fitness consequences of a delayed timing of breeding are expected to affect the temporal characteristics of the whole annual breeding system. One major problem in quantifying the fitness relevance of timing is that individual differences between pairs may cause the seasonal trend. Differentials in juvenile survival due to pre-fledging timing decisions often only appear after fledging of the chicks. Therefore, timing decisions in the post-fledging period, i.e., the duration of parental care, might additionally influence juvenile survival. We tested the effects of timing and parental competence on the post-fledging survival of second-brood juvenile Barn Swallows (Hirundo rustica L.) by swapping earlier and later hatching clutches and radio-tracking the juvenile subjects. The mark-recapture models controlled for the effects of duration of post-fledging care and food availability. There was an annually varying negative seasonal trend in offspring survival that was associated with environmental conditions. Directional selection for early breeding occurred in the two years with scarce autumnal food supply. Furthermore, we found strong selection for long post-fledging parental care. The duration of care neither declined seasonally, nor did longer care compensate for the seasonal decline of juvenile survival. Hence, the reproductive output three weeks after fledging was determined by two parental timing decisions: the timing of breeding and the timing of family breakup. We suggest that differential survival of second-brood fledglings in relation to these decisions is an important part of the selective mechanisms shaping the reproductive system of Barn Swallows.     

ESTABLISHING WATERSHED MANAGEMENT IN LAW: NEW ZEALAND'S EXPERIENCE1

ABSTRACT: New Zealand is one of the first countries in the world to enshrine the concept of watershed management in law, through institutional arrangements and the Resource Management Act of 1991 ‐ a law constructed on a watershed management legacy begun in 1941. This paper outlines the development of New Zealand's Resource Management Act (as it applies to water management) and the lessons that have been learned in its implementation.     

Reducing Indoor Air Formaldehyde Concentrations

Urea-formaldehyde resin bonded partlcleboard, medium density fiberboard and plywood paneling are used as flooring, wall paneling, for cabinet work and in furniture, and are present In almost every office, home and public building. If large quantities of these products are used In poorly ventilated spaces, high manufacturing quality control is necessary to avoid problems of latent formaldehyde release. Indoor air formaldehyde concentrations depend on the nature of the product, the product surface to air volume (loading) factor, temperature, humidity, age and product emission rates. Standard test methods are now available for measuring product emission rates that make It possible to predict the performance of UF-bonded pressed wood materials If use conditions and environmental parameters are known. Recent modifications In adhesive and board manufacturing parameters have made It possible to reduce formaldehyde emission significantly, and UF-bonded wood products are now capable of meeting indoor air quality standard levels of 0.1 ppm under almost all customary loading conditions.