Summary 0[ We tested for costs of chick rearing in the black!legged kittiwake Rissa tridactyla "Linnaeus# by removing entire clutches from 038 of 394 randomly selected nests\ in which one or both mates was colour!banded[ After the manipulation\ we monitored adult nest attendance and body condition at unmanipulated and manipulated nests\ and measured the survival and fecundity of these adults the following year[ 1[ Late in the chick!rearing period\ adults from unmanipulated nests "i[e[ with chicks# went on signi_cantly longer foraging trips\ and were signi_cantly lighter for their size\ than adults from manipulated nests "i[e[ without chicks#[ 2[ Adults from unmanipulated nests also survived to the following nesting season at a signi_cantly lower rate than those from the manipulated nests "9=787 vs[ 9=842#\ suggesting that attempting to raise chicks can reduce life expectancy by 44)[ 3[ There was a tendency for adults from nests that were unmanipulated in year one to have lower reproductive success in year two\ primarily because of reduced~edging success\ and a higher incidence of non!breeding[ 4[ These _ndings suggest that mass loss in kittiwakes during chick rearing may not be adaptive[ Raising chicks can lead to reproductive costs\ and the causal mechanism appears to be a reduction in body condition[ 5[ We compare our results with previous brood "or clutch# size manipulation experi! ments that have measured adult body condition\ survival and:or future fecundity[ Although the empirical evidence suggests that long!lived species are more likely to experience survival costs than short!lived species\ we believe the opposite may be true[ We suggest that shifting the experimental protocol of cost of reproduction studies from brood enlargements "an approach taken in most prior studies# to brood reductions will provide more accurate quanti_cations of naturally occurring costs[ 6[ The cost of reproduction is one mechanism proposed to explain the reduced survival rates reported for kittiwake populations in the North Atlantic relative to those in the North Paci_c ocean[ Oceanographic data\ however\ suggest that lower food avail! ability may limit survival of kittiwakes in the North Atlantic where a deeper mixed layer and reduced primary production combine to make conditions less favourable for this seabird during the winter months[ Key!words] body condition\ clutch!size manipulation\ cost of reproduction\ life history trade!o}\ parental investment[ Journal of Animal Ecology "0887# 56\ 716Ð730

Over the next century, climate change will dramatically alter natural resource management. Specifically, historical reference conditions may no longer serve as benchmarks for restoration, which may foster a "why bother?" attitude toward ecological restoration. We review the potential role for riparian restoration to prepare ecological systems for the threats posed by climate change. Riparian ecosystems are naturally resilient, provide linear habitat connectivity, link aquatic and terrestrial ecosystems, and create thermal refugia for wildlife: all characteristics that can contribute to ecological adaptation to climate change. Because riparian systems and the projected impacts of climate change are highly variable geographically, there is a pressing need to develop a place-based understanding of climate change threats to riparian ecosystems. Restoration practitioners should consider how they can modify practices to enhance the resilience of riparian ecosystems to climate change. Such modifications may include accelerating the restoration of private lands, participating in water management decisions, and putting the emerging field of restoration genetics into practice.

Citizen science, big data, and a habitat marketplace enable dynamic habitat for migratory birds in California’s Central Valley.

We conducted a study to determine mechanisms constraining population recovery of pigeon guillemots Cepphus columba following the 1989 'Exxon Valdez' oil spill. We asked whether recovery was limited by continuing exposure to residual oil, reduced prey availability, or other causes. Our approach was to compare demographic, physiological, and behavioral parameters between an oiled site pre-and post-spill, and between the oiled site and an unoiled site post-spill. Adult mass, body condition, and nestling survival were significantly lower at the oiled site post-spill compared to pre-spill. After the spill, guillemots increased in number at the unoiled site and chicks fledged at significantly heavier weights than at the oiled site, where populations remained depressed. Elevated hepatic cytochrome P4501A (CYP1A), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) enzyme activities detected in adult guillemots a decade after the spill at the oiled site suggest that continued exposure to residual oil may have limited population recovery, although reduced availability of sand lance, a preferred forage fish, may have also played a role. Previous studies conducted at the oiled site demonstrated that guillemot chick growth and reproductive success were positively related to the percentage of high-lipid forage fishes, such as sand lance, in the chick diet. Aspects of sand lance life history and the pattern of 'Exxon Valdez' oil deposition strongly suggest that sand lance were impacted by the spill, although we lack direct evidence of this, and reductions in this species' abundance may have also resulted from natural causes. Our study suggests that the recovery of a top-level generalist predator may be constrained by both direct effects (continued exposure to residual oil) and indirect effects (reduced availability of a key prey species) following a large-scale perturbation. Furthermore, it demonstrates that recovery following oil spills may take considerably longer for certain species than the few years that have been proposed as typical for marine birds.