Point Blue Conservation Science

About: Point Blue Conservation Science is a nonprofit organization based out in Petaluma, California, United States. It is known for research contribution in the topics: Population & Foraging. The organization has 151 authors who have published 330 publications receiving 11929 citations. The organization is also known as: Point Reyes Bird Observatory.

Environmental temperatures, artificial nests, and incubation of Cassin's auklet

Abstract: Hatching success in birds is influenced by the temperature and turning rate of the egg, but our understanding of the environmental factors that effect incubation temperatures and egg turning rates in birds is limited. Especially little is known of these effects for species that nest in burrows or crevices, such as the Cassin's auklet (Ptychoramphus aleuticus). On Southeast Farallon Island, California, USA, a subset of the Cassin's auklet (hereafter auklet) population nest in artificial nest boxes. The nest boxes are above ground and made out of a single layer of plywood. Temperatures in unshaded nest boxes can increase significantly with high ambient temperatures (to >35° C). Shaded structures put on top of occupied nest boxes help mediate nest box temperatures, but the effects of elevated temperatures on auklet incubation behaviors and egg viability remain equivocal. We used egg data loggers to measure the temperatures and turning rates of auklet eggs in natural burrows, shaded nest boxes, and unshaded nest boxes on Southeast Farallon Island. Nest box (13.93 ± 1.26° C) and egg (37.43 ± 1.92° C) temperatures were highest and most variable in unshaded nest boxes. Mean hourly egg turning rate was 2.11 ± 2.02 turns/hour and turning rates were greater at night. Egg turning rates also varied with fluctuating nest and egg temperatures, being positively correlated with nest temperatures during the day and negatively correlated with egg temperatures during the night. Our results suggest that nest box design can influence incubation behaviors of breeding birds. As seasonal temperatures and the number of extreme heat events rise, understanding the impacts of temperature on auklets nesting in artificial nests can have positive implications for conservation and management of the species, such as implementing improved artificial nest box designs to prevent overheating of burrow nesting seabirds. © 2015 The Wildlife Society.

Further Insights into Nest-site Competition between Adelie and Chinstrap Penguins

Abstract: istry of plurilocular reproductive stages. Protoplasma 77: 1-13. BOERSMA. D. 1975. Adaptations of Galapagos penguins for life in two different environments. Pp. 101-114 in The biology of penguins (B. Stonehouse, Ed.). London, Macmillan. CROLL, D. A., & R. W. HOLMES. 1982. A note on the occurrence of diatoms on the feathers of diving seabirds. Auk 99: 765-766. RAND^LL, R. M. 1983. Biology of the Jackass Penguin Spheniscus demersus (L.) at St Croix Island, South Africa. Unpublished Ph.D. dissertation. Port Elizabeth, South Africa, Univ. Port Elizabeth.

Predictive habitat suitability models for nesting woodpeckers following wildfire in the Sierra Nevada and Southern Cascades of California

Abstract: Woodpeckers are often focal species for informing management of recently burned forests. Snags generated by wildfire provide key nesting and foraging resources for woodpeckers, and nest cavities excavated by woodpeckers are subsequently used by many other species. Habitat suitability models applicable in newly burned forest are important management tools for identifying areas likely to be used by nesting woodpeckers. Here we present and test predictive models for mapping woodpecker nest-site habitat across wildfire locations that can be used to inform post-fire planning and salvage logging decisions. From 2009 to 2016, we monitored 313 nest sites of 4 species—Black-backed Woodpecker (Picoides arcticus), Hairy Woodpecker (Dryobates villosus), White-headed Woodpecker (D. albolarvatus), and Northern Flicker (Colaptes auratus)—from 3 wildfires in the Northern Sierra Nevada and Southern Cascades 1–5 yr after fire. Using these data, we developed habitat suitability index models that compared nest vs. non-nest sites for each species using (1) exclusively remotely sensed covariates, and (2) combinations of remotely sensed and field-collected covariates. We emphasized predictive performance across wildfire locations when selecting models to retain generalizable habitat relationships useful for informing management in newly burned locations. We identified models for all 4 species with strong predictive performance across wildfire locations despite notable variation in conditions among locations, suggesting broad applicability to guide post-fire management in the Sierra Nevada region. Top models for nest-site selection underscored the importance of high burn severity at the local scale, lower burn severity at the 1-km scale, mid-sized nest-tree diameters, and nest trees with broken tops. Models restricted to remotely sensed covariates exhibited similar predictive performance as combination models and are valuable for mapping habitat across entire wildfire locations to help delineate project areas or habitat reserves. Combination models are especially relevant for design of silvicultural prescriptions.

How is adaptive potential distributed within species ranges

Abstract: Quantitative genetic variation (QGV) represents a major component of adaptive potential and, if reduced toward range-edge populations, could prevent a species' expansion or adaptive response to rapid ecological change. It has been hypothesized that QGV will be lower at the range edge due to small populations-often the result of poor habitat quality-and potentially decreased gene flow. However, whether central populations are higher in QGV is unknown. We used a meta-analytic approach to test for a general QGV-range position relationship, including geographic and climatic distance from range centers. We identified 35 studies meeting our criteria, yielding nearly 1000 estimates of QGV (including broad-sense heritability, narrow-sense heritability, and evolvability) from 34 species. The relationship between QGV and distance from the geographic range or climatic niche center depended on the focal trait and how QGV was estimated. We found some evidence that QGV declines from geographic centers but that it increases toward niche edges; niche and geographic distances were uncorrelated. Nevertheless, few studies have compared QGV in both central and marginal regions or environments within the same species. We call for more research in this area and discuss potential research avenues related to adaptive potential in the context of global change.