Anthropogenically induced global climate change has profound implications for marine ecosystems and the economic and social systems that depend upon them. The relationship between temperature and individual performance is reasonably well understood, and much climate-related research has focused on potential shifts in distribution and abundance driven directly by temperature. However, recent work has revealed that both abiotic changes and biological responses in the ocean will be substantially more complex. For example, changes in ocean chemistry may be more important than changes in temperature for the performance and survival of many organisms. Ocean circulation, which drives larval transport, will also change, with important consequences for population dynamics. Furthermore, climatic impacts on one or a few 'leverage species' may result in sweeping community-level changes. Finally, synergistic effects between climate and other anthropogenic variables, particularly fishing pressure, will likely exacerbate climate-induced changes. Efforts to manage and conserve living marine systems in the face of climate change will require improvements to the existing predictive framework. Key directions for future research include identifying key demographic transitions that influence population dynamics, predicting changes in the community-level impacts of ecologically dominant species, incorporating populations' ability to evolve (adapt), and understanding the scales over which climate will change and living systems will respond.

/pdf/the-impacts-of-climate-change-in-coastal-marine-systems-2nveckceet.pdf

The impacts of climate change in coastal marine systems.

Anthropogenically induced global climate change has profound implications for marine ecosystems and the economic and social systems that depend upon them. The relationship between temperature and individual performance is reasonably well understood, and much climate-related research has focused on potential shifts in distribution and abundance driven directly by temperature. However, recent work has revealed that both abiotic changes and biological responses in the ocean will be substantially more complex. For example, changes in ocean chemistry may be more important than changes in temperature for the performance and survival of many organisms. Ocean circulation, which drives larval transport, will also change, with important consequences for population dynamics. Furthermore, climatic impacts on one or a few leverage species may result in sweeping community-level changes. Finally, synergistic effects between climate and other anthropogenic variables, particularly fishing pressure, will likely exacerbate climate-induced changes. Efforts to manage and conserve living marine systems in the face of climate change will require improvements to the existing predictive framework. Key directions for future research include identifying key demographic transitions that influence population dynamics, predicting changes in the community-level impacts of ecologically dominant species, incorporating populations ability to evolve (adapt), and understanding the scales over which climate will change and living systems will respond.

/pdf/syntheses-the-impacts-of-climate-change-in-coastal-marine-2mwsfi57x1.pdf

SYNTHESES The impacts of climate change in coastal marine systems

Handbook of the Birds of Europe, the Middle East and North Africa: the Birds of the Western Palaearctic. Volume 2. Hawks to Bustards

/pdf/ecosystems-their-properties-goods-and-services-s3a98obedp.pdf

Ecosystems, their properties, goods and services

Oddity and the ‘confusion effect’ in predation

Global warming is expected to result in an acceleration in current rates of sea level rise, inundating many low-lying coastal and intertidal areas. This could have important implications for organisms that depend on these sites, including shorebirds that rely on them for feeding habitat during their migrations and in winter. We modeled the potential changes in the extent of intertidal foraging habitat for shorebirds at five sites in the United States that currently support internationally important numbers of migrating and wintering birds. Even assuming a conservative global warming scenario of 2°C within the next century (the most recent projections range between 1.4°C and 5.8°C), we project major intertidal habitat loss at four of the sites (Willapa Bay, Humboldt Bay, San Francisco Bay, and Delaware Bay). Projected losses range between 20% and 70% of current intertidal habitat. Such losses might jeopardize the ability of these sites to continue to support their current shorebird numbers. The mo...

Global climate change and sea level rise: potential losses of intertidal habitat for shorebirds

https://www.fs.fed.us/psw/publications/documents/psw_gtr191/psw_gtr191_1119-1122_galbraith.pdf

Global Climate Change and Sea Level Rise: Potential Losses of Intertidal Habitat for Shorebirds

Although high mortality rates have been demand mud flats form the major feeding habitat for onstrated for shorebirds by the analysis of large numbers of shorebirds that winter on the estuary. band recoveries and studies of marked birds (Martin-LGf 1961; Boyd 1962; Holmes 1966; METHODS Soikelli 1970), there is little information on Using a spotting scope and binoculars, we watched the causes of shorebird mortality. Goss-Cusmany diurnal raptors while they hunted on Bolinas tard (1970) theorized that flocking by some Lagoon. When we saw a raptor eat prey, we col-

Raptor Predation on Wintering Shorebirds

AssmAcr.-This six-year study describes the breeding of a partly resident, partly migrant population of Snowy Plovers (Charudrius alexundrinus) in California. Migrants arrived between 6 January and 27 April, with females preceding males. Migrant males did not pair as early as resident males, whereas resident and migrant females paired at about the same time. Early pairbonds often were with the same mate in two consecutive years. Egg laying occurred from 23 March to 13 July. Replacement clutches were initiated between 11 April and 11 July, typically seven days after loss of the preceding one, and usually with the same mate. Over the season, the time required for a pair to complete the three-egg clutch decreased from five days to four days. During egg laying, males spent more time in the nesting territory and on the incomplete clutch than did females. Incubation averaged 28.4 days early in the season, but only 26.9 days late in the season. During daytime, males averaged only 10.7% of the incubation time, but they appeared to be the main incubators at night. Over six years, 58.2% of 189 clutches hatched at least one chick. Females normally deserted hatched young within six days; males attended the young for 29 to 47 days. Fledging typically occurred at about 31 days of age. Over six years, 39% to 42% of 296 chicks fledged. After deserting broods, at least 22 of 60 females renested with new mates. At least 10 of 18 males fledging chicks before 1 July renested with new mates, and in at least 13 of 27 cases, males losing broods before 1 July renested, usually with new mates. Males appeared to outnumber females by 1.4: 1. Sexual differences in survival rates are nearly sufficient to account for the difference in sex ratio. We suggest hat the female’s serial polyandry may be a facultative response to a skewed sex ratio. Received 12 Mar. 1985, accepted 19 Sept. 1985.

Mating system and reproductive success of a small population of polygamous Snowy Plovers

--Snowy Plovers (Charadrius alexandrinus) nesting on the exposed lake bed surrounding Mono Lake, California lose up to 40% of their clutches. Most are destroyed by predators, predominantly California Gulls (Larus californicus). In 1978 Snowy Plover reproduction was estimated at 0.49-0.70 fledged young per female. Population stability was estimated to require 0.80 fledged young per female. A series of experiments with artificial clutches placed at different densities in the nesting area demonstrates that the predators can have an effect on the plovers' nesting success that is dependent upon their nest density. The maintenance of low nesting density is an important antipredator adaptation. We consider predation on clutches and broods to be the major limiting factor on the Snowy Plover population at Mono Lake. Received 18 January 1982, accepted 27 May 1982. MANY workers have hypothesized that shorebird mating systems, territorial behavior and nest-dispersion patterns evolving together have increased the species' ability to exploit food resources or thwart predators, thereby enhancing the chances of successful breeding (e.g. Holmes 1966, 1972; Oring and Knudson 1972; Graul 1973; Pitelka et al. 1974; Safriel 1975). The effect of food resources and predators on shorebird breeding success has largely gone unmeasured. In fact, few workers have measured breeding success, because shorebirds' precocial young are almost impossible to relocate after they leave the nest. Tinbergen et al. (1967) conducted the first experiments demonstrating that the dispersion of birds' nests may affect their survival. They found that the rate at which Carrion Crows (Corvus corone) took camouflaged, scattered chicken eggs increased with increasing egg density. Goransson et al. (1975) exposed camouflaged dwarf hen eggs to Carrion Crows and Herring Gulls (Larus argentatus) and obtained similar results, except when the eggs were in an area defended by Lapwings (VaneIIus vanellus), which drove the predators from the area. Gottfried's (1978) experiments with imitation landbird nests in old-field habitat showed no relationship between the rate of nest loss and nest density. He suspected that the differences 13 between his and the previously mentioned experiments may have been related to the types of predators. Snakes were responsible for most losses at his study site. The results of these and other experiments (Andersson and Wiklund 1978) indicate that a wide dispersion of nests may be the best strategy for birds unable to defend their nests against visually cued avian predators. We have measured breeding success of the Snowy Plover (Charadrius alexandrinus nivosus) at several localities in California as part of a larger study of the species' breeding status in the state. Noting a particularly wide spacing of nests and a high level of nest loss to predators at Mono Lake, we undertook experiments with artificial nests to determine the value this wide spacing might have in reducing the predators' effects on nesting success. This paper describes how we estimated breeding success, how the estimated success relates to the level of production needed for maintenance of population size, and how predators limit nesting success and possibly regulate the size of the breeding population. STUDY AREA AND METHODS Study area.--The study was conducted at Mono Lake, Mono County, California. This nearly elliptical, 15-km by 20-km, alkaline lake lies in a closed The Auk 100: 13-24. January 1983 14 P^GE ET ̂ L. [Auk, Vol. 100

Gary W. Page

Papers

Global climate change and sea level rise: potential losses of intertidal habitat for shorebirds

Global Climate Change and Sea Level Rise: Potential Losses of Intertidal Habitat for Shorebirds

Raptor Predation on Wintering Shorebirds

Mating system and reproductive success of a small population of polygamous Snowy Plovers

Spacing out at Mono Lake: Breeding Success, Nest Density, and Predation in the Snowy Plover