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Community and city Facebook pages have proliferated in popularity in the last several years, offering a forum for residents to openly and publicly negotiate relations with urban wildlife, including coyotes. Contemporary shifts in North American coyote geographies (and the concomitant rise in community social media sites) thus open up interesting possibilities for exploring how public pedagogies might challenge problematic human-nature and urban-wild binaries. We begin this article by articulating why studying urban coyotes is an important task for the field of environmental education. Next, we develop our nascent theoretical framework of interspecies public pedagogy, which draws on theories of public pedagogy and naturecultures. We follow by methodologically situating this research within diverse ethnographic approaches, which we use to study Facebook community pages in two U.S. cities, Philadelphia, PA and Chino/Chino Hills, CA. Our analysis demonstrates how the pedagogical strategies residents employ encourage debates about how their lives are entangled with coyotes, land, and other people, and yet are limited in that they do not completely redefine the role of public urban spaces. Before discussing the implications of this research, we briefly explore some possibilities for interspecies public pedagogies in real-life public spaces, as well as in cyberspace.

This article reports on a study in which activity theory was used to design, implement, and analyze a 10-week curriculum unit about how honeybees collect nectar with a particular focus on complex systems concepts. Students (n = 42) in a multi-year kindergarten and 1st-grade classroom participated in this study as part of their 10 regular classroom activity. The curricular unit was composed of 4 specific activity types, each of which was intended to focus students on a particular dimension of the content: (a) Inquiry with BeeSign software was intended to help students explore the benefit of individual nectar-collecting behaviors for the hive as a whole; (b) traditional drawing activities were intended to help students learn the structures of 15 the bees; (c) participatory representation activities, in which students enacted the behavior of the bees as they collect nectar, were intended to help students link bee structures to individual behaviors; and (d) an embodied nectar-gathering game was intended to help the students recognize the challenges of finding nectar for individual bees. Pre- and posttest interviews reveal a shift in individual student understanding 20 as students progressed from discussing the superficial structures of the system to discussing both behaviors and functions.

This study examines first graders' epistemic reasoning, in tacit "practical epistemologies" reflected in thinking about an investigation of their own design. I analyzed children's epistemic reasoning, following a design experiment scaffolding increasing regulation of scientific inquiry in a domain they studied in depth. Participants consisted of children in two first grade classes (n = 35). The study capitalizes on the final phase of the design experiment, wherein pairs assumed substantial responsibility for design and implementation of an investigation pursuing their own question. I conducted structured interviews with each pair, eliciting their thinking about their investigation. Forty-three percent of the children attributed uncertainty to their findings. Forty-nine percent transcended phenomenon-based reasoning in thinking about how to improve their study, reasoning instead in terms of relation between variables. Forty percent posited additional potentially influential variables, reflecting a tacit understanding of the lack of any straightforward one-to-one correspondence between cause and effect. These findings suggest that epistemic reasoning is plastic, sensitive to instructional opportunities. I argue that the children's relatively deep familiarity with the domain, experience in assuming increasing responsibility for structuring scientific inquiry, and investment they had in their own investigations contributed to the surprisingly robust epistemic reasoning they revealed in this context. (Contains 3 tables, 11 figures, and 10 footnotes.)

Many studies demonstrate that urban noise interferes with animal communication by masking acoustic signals such as birdsong, but the functional consequences of impaired communication are still not well understood. Song is a long-distance signal that functions to attract a mate and defend a territory, so a reduction in communication distance could negatively influence a male's reproductive or competitive success. Reduced territorial success could manifest as more frequent territorial intrusions, reduced territory quality or reduced territory size. Although many bird species sing at higher amplitude in noise pollution, communication distance is still reduced in noisy urban soundscapes. Therefore, we examined the relationship between communication distance and territory size for male white-crowned sparrows, Zonotrichia leucophrys , across an urban–rural gradient in the San Francisco Bay Area, California, U.S.A., in Spring 2021. We mapped territories and calculated territory size as the 75% utilization distribution using a kernel density estimator. We measured the song amplitude as well as territory background and ambient noise levels, which we then used to calculate the communication distance of each song. We found that the communication distance of a bird's songs significantly predicted his territory size, such that birds with shorter communication distance tended to have smaller territories. This suggests that communication distance may influence the size of songbird territories. In keeping with this trend, urban birds had significantly smaller territories than rural birds. This finding strengthens our understanding of the link between communication and its fitness-related functions, an important frontier in the study of birdsong. It also underlines the potential complexity of the impacts of the anthropogenic soundscape upon animal behaviour. • Urban noise pollution limits the distance from which birdsong can be heard. • Birds with shorter communication distance held smaller breeding territories. • Urban birds held smaller breeding territories than rural birds. • Communication distance may be one determinant of territory size. [ABSTRACT FROM AUTHOR]

Bioacoustic monitoring can reveal aspects of animal behavior because many species vocalize in association with certain behaviors. Despite this, bioacoustics remain infrequently used to monitor animal behavior because of lack of knowledge of how vocalizations relate to behavior and the challenge of efficiently analyzing the large acoustic data sets necessary to capture relevant behaviors. Vocalizations and associated behaviors have been previously established for the colonial tricolored blackbird Agelaius tricolor, but efficient analysis of the acoustic data remains a challenge. Previous work with tricolored blackbird acoustic data relied on manually listening to recordings, which is not practical on large scales. Using software to automatically detect vocalizations of interest has potential to reduce analysis time. However, automated detection is prone to errors often caused by faint vocalizations, overlapping calls, and background noise. Thus, incorporating components of manual and automated analysis of acoustic data sets remains essential. To address these challenges, we deployed autonomous recording units at three tricolored blackbird colonies in California from 2019 to 2021 and analyzed acoustic data using a manual and a semiautomated analysis method. Specifically, we used tricolored blackbird male song, male chorus, female song, hatchling call, nestling call, and fledgling call to determine the approximate timing of breeding stages and number of breeding attempts, or pulses, for each colony. We found that using a semiautomated approach was more time efficient than manual analysis, while using comparable numbers of recordings and obtaining equivalent information from the colonies. The odds of correct detections of vocalizations using the semiautomated method were generally lower for fainter vocalizations and colonies with high background noise. Overall, the semiautomated approach had tolerable rates of recall, precision, false positives, and false negatives. Our methodology adds to a growing body of literature addressing acoustic analyses, especially for colonial species and where questions of breeding phenology are important. [ABSTRACT FROM AUTHOR]

Quantifying animal movement is a central component of ecological inquiry. Movement patterns provide insights into how animals make habitat decisions in pursuit of their life‐history requirements. Within this context, animals are expected to modulate their movement when navigating landscape complexities like steep or uneven slopes. However, the analytical tendency to predict animal movement as a function of bivariate (x, y) telemetry data (i.e. 2D methods) excludes such complexities and presumes that the landscapes over which this movement occurs are completely flat. Failure to consider vertical dimensionality may inhibit quantification and interpretation of animal behaviors, such as outputs of hidden Markov models (HMMs) built upon geometric measurements of animal movement like step length and turning angle. To explore the analytical consequences of this assumption, we utilized a dataset of GPS collared pumas Puma concolor in the Santa Cruz mountains of central California. We fit HMMs using traditional 2D step lengths and turning angles and compared them to HMMs built upon movement geometries in which we incorporated vertical dimensionality (i.e. 2D+). We then used a combination of quantitative inspection of model outputs and visual evaluation in 3D rendering software to understand what new states and biological interpretations can be facilitated by using 2D+ data. We found that 2D+ HMMs outperformed 2D HMMs in their ability to explain variation in vertical dimensionality. Furthermore, 2D+ models were able to isolate distinctive behavioral states associated with vertical dimensionality, such as movements on and off ridgelines. Our results show that 2D+ techniques enable researchers to directly investigate variation in animal movement and behavioral states across complex landscapes. We discuss the implications of our results for future study of animal behavior and energetics as well as illustrate how our methods can be tractably incorporated into HMMs to enable researchers to gain greater insights into animal movement ecology. [ABSTRACT FROM AUTHOR]

Persistent soil seed banks are characteristic of Arctostaphylos (Ericaceae) species in the Mediterranean‐climate California Floristic Province. While most species are obligate seeders, regeneration of stands of all Arctostaphylos species ultimately depends on post‐fire seedling recruitment. Arctostaphylos seed banks are created, in large part, by scatter‐hoarding rodents. Variation in fruit morphology, therefore, is expected to impact the Arctostaphylos–rodent interaction. Seeds produce sufficient rewards (nutritious mature embryo) to entice rodents to disperse and ultimately bury seeds in the soil. Hard seed coats increase the time required to extract the embryo, encouraging rodents to choose storage over immediate predation, and nutlets are frequently empty. We assessed the variation of fruit nutlet fusion and seed viability among 38 Arctostaphylos taxa. Factors such as latitude, elevation, life history, ploidy, and phylogenetic position were also analyzed. Generalized mixed‐effects models were used to determine the factors contributing to variation in fruit nutlet fusion and seed viability. Our results indicate that fruit volume and shape are the most important variables affecting nutlet fusion and seed viability. Additionally, other potential influences only show a weak correlation and are not predicted to significantly impact nutlet fusion or seed viability. These findings provide insights into evolved strategies used by plants to increase reproductive success via scatter‐hoarding rodents. Our study benefits the conservation and restoration of Arctostaphylos stands by emphasizing the importance of animal‐mediated dispersal and providing estimates of seed viability for different species. With the anticipated effects of climate change, such as departures from historic fire regimes, the preservation of the relationship between plants and animal foragers is crucial for the continued survival of Arctostaphylos and California's evergreen chaparral. [ABSTRACT FROM AUTHOR]

Many animals survive wildfires; however, the mechanisms used to detect and respond to fire have been poorly studied. Sensory cues like sight and sound are used to recognize threats (e.g. predators) and elicit escape responses in prey. Similarly, these cues might be used to detect an approaching wildfire. We tested whether the western fence lizard, Sceloporus occidentalis , responds to the sound of fire as a threat. We predicted that lizards living in burned areas would be more sensitive to the sound of fire than lizards in adjacent and urban areas, where fire suppression could have induced relaxed selection on fire responsiveness. We compared the behaviours of lizards following an experimental playback where we broadcast the sound of fire along with other control sounds (a predator, a common nonpredatory bird and a novel nonpredatory bird). We conducted our playbacks in 2019 in recently burned areas (using the survivors from the 2018 Woolsey Fire, southern California, U.S.A.), unburned adjacent areas and urban areas. We found that in burned areas, lizards responded more to the sound of fire than all three controls, but in urban areas, they responded more to both the sound of a predator and the sound of fire. Our results suggest that lizard responses to fire sounds are greater in an area that has recently experienced a wildfire than in an unburned area, and that urban areas create a complex evolutionary landscape that also increased antipredator behaviour for other biologically relevant stimuli. • Lizards surviving wildfires are more alert to fire sound than those in unburned areas. • Lizards living in urban areas reacted to fire sound similarly to wildfire survivors. • Both natural and human-driven disturbances can shape the behaviour of animals. • Fires are likely to be an important selective pressure on animal behaviour. [ABSTRACT FROM AUTHOR]

Mobile animals that traverse ecosystem boundaries can fundamentally reshape environments by providing critical nutrient and energy inputs to the ecosystems they inhabit. In particular, aggregations of seabirds often transform coastal and island ecosystems through large amounts of nutrient‐rich guano deposition. Anthropogenically driven losses of these subsidies can occur through changes in abundance of mobile species, including seabirds, and have been shown to drive whole‐scale ecosystem state change on islands. However, even though many species that forage on anthropogenic food sources are highly mobile and may thus play important roles in moving nutrients from urban systems to otherwise conserved ecosystems, the impacts of anthropogenic supplements on spatial subsidies have been largely ignored. Here we examine the effects of large nesting colonies of Western Gulls (Larus occidentalis), a generalist carnivore known to forage on human refuse, on the Channel Islands of California. Specifically, we explore how their foraging on human subsidies may change nutrient deposition patterns at their relatively remote and protected breeding islands. We equipped gulls with GPS loggers to assess the frequency of urban foraging, and we partnered this tracking data with bird density data to estimate the rate of wild and urban‐derived guano deposition on two different islands. Consistent with research on other gull species, we found high (up to 40%) but island‐specific rates of urban foraging, resulting between 66 and 93 kg ha−1 of guano in these two sites during the breeding season, a level greater than half the amount of fertilizer applied annually in typical commercial agricultural settings and likely the primary source of nitrogen and phosphorus inputs to this system. Specifically, we estimate that 27 kg ha−1 year−1 of nutrient‐rich guano is shuttled to these otherwise isolated islands from anthropogenic sources. This research highlights the large shadow (i.e., footprint) that human activity can cast on even remote ecosystems by driving significant nutrient enrichment through impacts on animal behavior and connectivity. [ABSTRACT FROM AUTHOR]

A fundamental assumption in predator–prey ecology is that prey responses comprise two main stages: escape when attack occurs or appears imminent and avoid the threat by seeking refuge until it has passed. While numerous studies have examined either initial prey responses to an approaching predator (flight initiation distance, FID), or subsequent hiding behaviour (e.g. latency to resume activity), to our knowledge, no previous studies have repeatedly tested multiple individuals in nature to quantify whether initial escape tendencies, behaviour during the escape and latency to resume activity are repeatable, and whether these stages of the antipredator response are correlated. The goal of this study was to explore how consistent spatial differences in rates of human activity shape risk-sensitive behaviour throughout multiple steps of the antipredator response (to humans) in California ground squirrels, Otospermophilus beecheyi , tested in various group sizes and environmental contexts across time. Our study provides the first example showing that, as predicted: FIDs, latencies to resume activity and other post-FID aspects of prey responses were repeatable and positively correlated at the among-individual level. This correlation is ecologically important in that it provides an underlying mechanism for a trade-off involving not only the cost versus benefit of early versus late escape, or early versus late emergence from refuge, but for a trade-off based on variation in fearfulness expressed across stages. Furthermore, we found that human activity influenced some, but not all, stages of the antipredator response. • Prey face trade-offs across multiple stages of the antipredator response. • We explore repeatability of antipredator responses and correlations between stages. • Human activity influenced some, but not all, stages of the antipredator response. • Multiple stages of the response were repeatable and highly correlated. • Our study offers insights into links between animal behaviour, humans and ecology. [ABSTRACT FROM AUTHOR]

BACKGROUND: Exposure to ambient air pollution particulate matter (PM) is associated with increased risk of dementia and accelerated cognitive loss. Vascular contributions to cognitive impairment are well recognized. Chronic cerebral hypoperfusion (CCH) promotes neuroinflammation and blood– brain barrier weakening, which may augment neurotoxic effects of PM. OBJECTIVES: This study examined interactions of nanoscale particulate matter (nPM; fine particulate matter with aerodynamic diameter =200 nm) and CCH secondary to bilateral carotid artery stenosis (BCAS) in a murine model to produce white matter injury. Based on other air pollution interactions, we predicted synergies of nPM with BCAS. METHODS: nPM was collected using a particle sampler near a Los Angeles, California, freeway. Mice were exposed to 10 wk of reaerosolized nPM or filtered air (FA) for 150 h. CCH was induced by BCAS surgery. Mice (C57BL/6J males) were randomized to four exposure paradigms: a) FA, b) nPM, c) FA+BCAS, and d) nPM+BCAS. Behavioral outcomes, white matter injury, glial cell activation, inflammation, and oxidative stress were assessed. RESULTS: The joint nPM+BCAS group exhibited synergistic effects on white matter injury (2.3× the additive nPM and FA+BCAS scores) with greater loss of corpus callosum volume on T2 magnetic resonance imaging (MRI) (30% smaller than FA group). Histochemical analyses suggested potential microglial-specific inflammatory responses with synergistic effects on corpus callosum C5 immunofluorescent density and whole brain nitrate concentrations (2.1× and 3.9× the additive nPM and FA+BCAS effects, respectively) in the joint exposure group. Transcriptomic responses (RNA-Seq) showed greater impact of nPM+BCAS than individual additive effects, consistent with changes in proinflammatory pathways. Although nPM exposure alone did not alter working memory, the nPM+BCAS cohort demonstrated impaired working memory when compared to the FA+BCAS group. DISCUSSION: Our data suggest that nPM and CCH contribute to white matter injury in a synergistic manner in a mouse model. Adverse neurological effects may be aggravated in a susceptible population exposed to air pollution. [ABSTRACT FROM AUTHOR]

This study examines the occurrence of humpback whale (Megaptera novaeangliae) song in the northeast Pacific from three years of continuous recordings off central California (36.713°N, 122.186°W). Song is prevalent in this feeding and migratory habitat, spanning nine months of the year (September–May), peaking in winter (November–January), and reaching a maximum of 86% temporal coverage (during November 2017). From the rise of song in fall through the end of peak occurrence in winter, song length increases significantly from month to month. The seasonal peak in song coincides with the seasonal trough in day length and sighting-based evidence of whales leaving Monterey Bay, consistent with seasonal migration. During the seasonal song peak, diel variation shows maximum occurrence at night (69% of the time), decreasing during dawn and dusk (52%), and further decreasing with increasing solar elevation during the day, reaching a minimum near solar noon (30%). Song occurrence increased 44% and 55% between successive years. Sighting data within the acoustic detection range of the hydrophone indicate that variation in local population density was an unlikely cause of this large interannual variation. Hydrographic data and modeling of acoustic transmission indicate that changes in neither habitat occupancy nor acoustic transmission were probable causes. Conversely, the positive interannual trend in song paralleled major ecosystem variations, including similarly large positive trends in wind-driven upwelling, primary productivity, and krill abundance. Further, the lowest song occurrence during the first year coincided with anomalously warm ocean temperatures and an extremely toxic harmful algal bloom that affected whales and other marine mammals in the region. These major ecosystem variations may have influenced the health and behavior of humpback whales during the study period. [ABSTRACT FROM AUTHOR]

Major ecological realignments are already occurring in response to climate change. To be successful, conservation strategies now need to account for geographical patterns in traits sensitive to climate change, as well as climate threats to species-level diversity. As part of an effort to provide such information, we conducted a climate vulnerability assessment that included all anadromous Pacific salmon and steelhead (Oncorhynchus spp.) population units listed under the U.S. Endangered Species Act. Using an expert-based scoring system, we ranked 20 attributes for the 28 listed units and 5 additional units. Attributes captured biological sensitivity, or the strength of linkages between each listing unit and the present climate; climate exposure, or the magnitude of projected change in local environmental conditions; and adaptive capacity, or the ability to modify phenotypes to cope with new climatic conditions. Each listing unit was then assigned one of four vulnerability categories. Units ranked most vulnerable overall were Chinook (O. tshawytscha) in the California Central Valley, coho (O. kisutch) in California and southern Oregon, sockeye (O. nerka) in the Snake River Basin, and spring-run Chinook in the interior Columbia and Willamette River Basins. We identified units with similar vulnerability profiles using a hierarchical cluster analysis. Life history characteristics, especially freshwater and estuary residence times, interplayed with gradations in exposure from south to north and from coastal to interior regions to generate landscape-level patterns within each species. Nearly all listing units faced high exposures to projected increases in stream temperature, sea surface temperature, and ocean acidification, but other aspects of exposure peaked in particular regions. Anthropogenic factors, especially migration barriers, habitat degradation, and hatchery influence, have reduced the adaptive capacity of most steelhead and salmon populations. Enhancing adaptive capacity is essential to mitigate for the increasing threat of climate change. Collectively, these results provide a framework to support recovery planning that considers climate impacts on the majority of West Coast anadromous salmonids. [ABSTRACT FROM AUTHOR]

Abstract Predation is a critical ecological process that alters the structure and functioning of ecosystems through density-mediated and trait-mediated effects on lower trophic levels. Although studies have focused on harvest-driven reductions in abundances and sizes of targeted species, human harvest also alters species morphologies, life histories, and behaviors by selection, plasticity, and shifts in species interactions. Restricting harvest can recover the biomass of targeted species, but it is less clear how behavioral phenotypes recover, particularly relative to the impacts of potentially opposing pathways of human influence. We investigated the effects of protection on the behavioral traits of a marine fish assemblage, recording behavior of 1377 individual fishes of nine targeted kelp forest species across 16 California marine protected areas (MPAs) varying in age, protection level, and diver visitation. With long-term, full protection from harvest, all fish species exhibited shorter flight initiation distance (FID, or the distance at which an animal flees from an approaching threat) and longer time delays before fleeing, despite differences in trophic position, microhabitat use, and other ecological characteristics. These escape behaviors were amplified across new MPAs regardless of protection level, suggesting that recovery is slow and likely the result of differences in genetic or early-life experience among individuals in these long-lived species. Although the effects of full protection from harvest were partially offset by recovering populations of large piscivorous predators, the net effect of long-term, full protection on fish behavior was shorter FID. Additionally, all species had shorter FID at sites more frequently visited by divers, and this effect was greater in sites with long-term, full protection from fishing. To the extent that escape behavior is correlated with foraging behavior and predation rates, these results suggest that human-induced behavioral changes may affect ecosystem processes, even after abundances have recovered. If recovery of ecosystem functioning and services are the management goal, assessments should be broadened to include the recovery of functional traits (including behavior). [ABSTRACT FROM AUTHOR]

Abstract. Kangaroo rats are reported to have a mutualistic relationship with harvester ants through facilitation of burrow establishment, creation, and persistence. The relationship can, however, become more complex. We report observations of the giant kangaroo rat (Dipodomys ingens), a state and federally listed endangered species, repeatedly kleptoparasitizing harvester ants from a nearby nest in the Carrizo Plain, California. Though the relationship between kangaroo rats and harvester ants has been studied extensively and is believed to be mutualistic, under certain conditions this relationship can follow an alternate path of parasitism. [ABSTRACT FROM AUTHOR]

ABSTRACT: Lead poisoning is an important conservation concern for wildlife, and scavenging birds are especially at risk from consumption of carcasses of animals killed with lead ammunition. Because current methods to identify lead exposure require animal capture and blood collection, management would benefit from the development of a less costly and noninvasive behavioral test for illness in wild animals. We attempted to design such a test to identify lead exposure in California condors (Gymnogyps californianus) that we tracked with global positioning system (GPS) telemetry in southern California, USA, 2013–2016. We measured blood‐lead concentrations in tracked birds and expected that flight behavior would be influenced by lead exposure; thus, we measured the effect of blood‐lead concentrations on 2 different types of movement rates and on the proportion of time condors spent in flight. We found no effect of lead exposure on any of these 3 behavioral metrics. Our work suggests that the measurements we took of flight behaviors were not a useful tool in predicting lead exposure in the mildly to moderately exposed birds we studied. Wild birds are effective at hiding illness, especially condors who have a strong social hierarchy in which showing weakness is a disadvantage. However, focusing on behaviors other than flight, expanding the sample studied to include birds with a wider range of lead concentration values, or analyzing tissues such as feathers (rather than, or in addition to, blood) may be more useful for identification of lead exposure and other diseases that may limit wildlife populations. © 2017 This article is a U.S. Government work and is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

An experimental approach was used to investigate wintering waterfowl responses to introduced trail use at foraging sites with and without recreational trails in California, USA. Waterfowl were exposed to trail use in the form of two researchers walking levees adjacent to ponded habitat, and the number of waterfowl by species were compared before and after experimental walks in 40-m bands starting at the levee and extending 200 m into the ponds. The researchers recorded distances to the nearest individuals, responses of focal animals, and numbers of recreational trail users. The most numerous species were Ruddy Duck ( Oxyura jamaicensis), Northern Shoveler ( Anas clypeata), and scaup spp. ( Aythya affinis and A. marila). Recreational trail use rates at trail sites averaged 1 to 82 people/hr. The greatest difference in numbers of birds before vs. after experimental walks occurred in the two 40-m bands closest to the levee at non-trail sites (0-40 m [ t = 4.558, P = 0.0001], 40-80 m [ t = 3.775, P = 0.001]) and trail sites (0-40 m [ t = 3.049, P = 0.005], 40-80 m [ t = 1.808, P = 0.082]). The relationship between the ratio of beforeto after-walk waterfowl numbers vs. date since the start of the winter season ( r2 = 0.315, P = 0.102) and the total number of birds vs. the number of recreational trail users ( r2 = 0.041, P = 0.847) did not indicate increasing tolerance to trail use for waterfowl overall. However, species varied in their tolerances. Ruddy Duck numbers declined with increasing numbers of recreational trail users ( rho = -0.481, P = 0.017), while Northern Shoveler numbers increased ( rho = 0.456, P = 0.025). Distances (using the 95th percentile) that individual birds were recorded from researchers during experimental walks varied from approximately 170-200 m at both non-trail and trail sites. [ABSTRACT FROM AUTHOR]

We conducted a hacking project in 1986-1994 to restore a population of breeding Bald Eagles ( Haliaeetus leucocephalus) in central California, where the species had not nested in more than a half-century. We first documented breeding among release cohorts in 1993, and the population increased to 26 known occupied breeding territories by 2012, exceeding the recovery plan goal for central California. Not all Bald Eagle nesting in the region can be attributed to the hacking project, but because the first seven nesting pairs each included at least one released eagle, we believe that the project expedited the recovery of a Bald Eagle breeding population in central California. The proportion of Bald Eagles returning to breed increased for the final three cohorts in 1991-1994, when we released eaglets younger than the standard fledging age. Eaglets released at or beyond the standard fledging age dispersed relatively quickly, whereas eaglets released at a younger age established more regular feeding patterns at the hack tower, and were more often seen in future seasons. Reintroduction in central California was supported by previous protective measures for the recovery of the global population, particularly the ban on DDT. [ABSTRACT FROM AUTHOR]

Seabird aggregations at sea have been shown to be associated with concentrations of prey. Previous research identified Central California as a highly used foraging area for seabirds, with locally breeding seabirds foraging close to their colonies on Southeast Farallon Island. Herein, we focus on nonresident (i.e. non-locally breeding) seabird species off of Central California. We hypothesized that high-use foraging areas for nonresident seabirds would be influenced by oceanographic and bathymetric factors and that spatial and temporal distributions would be similar within planktivorous and generalist foraging guilds but would differ between them. With data collected by the Applied California Current Ecosystem Studies (ACCESS) partnership during cruises between April and October from 2004–2013, we developed generalized linear models to identify high-use foraging areas for each of six nonresident seabird species. The four generalist species are Phoebastria nigripes (black-footed albatross), Ardenna griseus (sooty shearwater), Ardenna creatopus (pink-footed shearwater), and Fulmarus glacialis (northern fulmar). The two planktivorous species are Phalaropus lobatus (red-necked phalarope) and Phalaropus fulicarius (red phalarope). Sea surface temperature was significant for generalist species and sea surface salinity was important for planktivorous species. The distance to the 200-m isobath was significant in five of six models, Pacific Decadal Oscillation with a 3-month lag in four models, and sea surface fluorescence, the distance to Cordell Bank, and depth in three models. We did not find statistically significant differences between distributions of individual seabird species within a foraging guild or between guilds, with the exception of the sooty shearwater. Model results for a multi-use seabird foraging area highlighted the continental shelf break, particularly within the vicinity of Cordell Bank, as the highest use areas as did Marxan prioritization. Our research methods can be implemented elsewhere to identify critical habitat that needs protection as human development pressures continue to expand to the ocean. [ABSTRACT FROM AUTHOR]

Freshwater crayfish are regarded as ecosystem engineers and keystone species. They act on various trophic levels and influence plant and animal species, community-level properties, and ecosystem processes. Comparisons of native and alien crayfish suggest greater negative effects of alien than native crayfish, but the species-specific roles of native and alien crayfish remain unclear. We used 2 enclosure experiments in streams to study biomass-related effects of the native Astacus astacus and Austropotamobius torrentium and the alien Pacifastacus leniusculus on available food types and the potential fate of these nutrients in the stream food web. In experiment 1, we compared the effects of crayfish (2 densities and a no-crayfish control) on leaf breakdown, production of leaf fragments, and accumulation of fine particulate matter (FPM). In experiment 2, we investigated predation by individual crayfish on Gammarus, Hydropsyche, and Arctic Char carrion. Pacifastacus leniusculus had stronger effects on leaf breakdown and a higher accrual of FPM than did the native species, and A. torrentium produced significantly more leaf fragments and fine particulate organic matter (FPOM) than did A. astacus. All 3 crayfish species preyed more successfully on slow-moving than on agile invertebrates, but native crayfish consumed significantly more Gammarus and trichopterans (A. torrentium) and fish carrion (A. astacus) than did P. leniusculus. All 3 crayfish species were polytrophic feeders, but A. torrentium had the strongest overall effects. Thus, the effect of native crayfish can be significantly greater than that of alien crayfish on food supply, predation on macroinvertebrates, and consumption of carrion when the effects are experimentally isolated. The difference in trophic roles suggests either better adaptation of native than alien crayfish to local food supplies or different niche exploitation. [ABSTRACT FROM AUTHOR]

Large trees are important to a wide variety of wildlife, including many species of conservation concern, such as the California spotted owl ( Strix occidentalis occidentalis). Light detection and ranging (Li DAR) has been successfully utilized to identify the density of large-diameter trees, either by segmenting the Li DAR point cloud into individual trees, or by building regression models between variables extracted from the Li DAR point cloud and field data. Neither of these methods is easily accessible for most land managers due to the reliance on specialized software, and much available Li DAR data are being underutilized due to the steep learning curve required for advanced processing using these programs. This study derived a simple, yet effective method for estimating the density of large-stemmed trees from the Li DAR canopy height model, a standard raster product derived from the Li DAR point cloud that is often delivered with the Li DAR and is easy to process by personnel trained in geographic information systems ( GIS). Ground plots needed to be large (1 ha) to build a robust model, but the spatial accuracy of plot center was less crucial to model accuracy. We also showed that predicted large tree density is positively linked to California spotted owl nest sites. [ABSTRACT FROM AUTHOR]

Benthic grazing by estuarine bivalves can be an important top-down process impacting pelagic food webs. In the low-salinity zone of the San Francisco Estuary mass balance calculations and models have reported that clams (especially the invasive Potamocorbula amurensis ) suppress phytoplankton blooms. However, spring blooms frequently occur. We aimed to understand this clam paradox using a biogeochemical modelling approach to evaluate the effects of clam grazing and excretion on phytoplankton production and nutrient uptake. The conceptual framework combines both the reduction of phytoplankton biomass by grazing and the role of ammonium (from clam excretion, wastewater plant discharge and sediment efflux) in minimizing chlorophyll accumulation, since phytoplankton cannot access nitrate (the major form of available nitrogen) for growth, due to ammonium suppression of nitrate uptake. We constructed the CLAMFLOW model by adding a clam module (with pathways of nitrogen for clam grazing, clam excretion and sediment efflux) to an existing phytoplankton-nitrogen-flow model. Whatever the parameter that was varied in the model (clam abundance, grazing, excretion, sediment efflux or flow) it decreased the peak nitrate uptake by the phytoplankton and shifted the time to reach peak uptake so delaying the likelihood of bloom initiation. Outcomes of the CLAMFLOW model were to demonstrate how clams can indirectly impact phytoplankton growth through excretion of ammonium, and to illustrate how most published laboratory filtration rates are likely too high for application in the field. There are management implications from using too high a clam grazing rate in models that may overestimate their impact on trophic estuarine and wetland productivity. We suggest that improved prediction of bloom occurrences requires the use of lower filtration rates combined with observed clam abundances, and a suitable combination of flow and ammonium source concentrations. This simple modular model (CLAMFLOW) offers portability to other ecosystems and is designed to connect with estuary scale three-dimensional circulation or numerical biogeochemical models. Our model and results are applicable to other situations, including aquaculture development and bivalve restoration efforts, where the biogeochemical effects of bivalves on phytoplankton productivity need to be quantitatively understood. [ABSTRACT FROM AUTHOR]

The article presents a study about the nutritional condition of juveniles and subadults of the California spiny lobster or Panulirus interruptus in Baja California Peninsula. It examines the impact of subtropical environmental conditions to the health condition of the lobsters. It cites the importance of several nutrition to the lobster's health including proteins, lipids, and carbohydrates.

Determining the detailed movements of individual animals often requires them to carry tracking devices, but tracking broad-scale movement of small bats (<30 g) has been limited by transmitter technology and long-term attachment methods. This limitation inhibits our understanding of bat dispersal and migration, particularly in the context of emerging conservation issues such as fatalities at wind turbines and diseases. We tested a novel method of attaching lightweight global positioning system ( GPS) tags and geolocating data loggers to small bats. We used monofilament, synthetic, absorbable sutures to secure GPS tags and data loggers to the skin of anesthetized big brown bats ( Eptesicus fuscus) in Colorado and hoary bats ( Lasiurus cinereus) in California. GPS tags and data loggers were sutured to 17 bats in this study. Three tagged bats were recaptured 7 months after initial deployment, with tags still attached; none of these bats showed ill effects from the tag. No severe injuries were apparent upon recapture of 6 additional bats that carried tags up to 26 days after attachment; however, one of the bats exhibited skin chafing. Use of absorbable sutures to affix small tracking devices seems to be a safe, effective method for studying movements of bats over multiple months, although additional testing is warranted. This new attachment method has the potential to quickly advance our understanding of small bats, particularly as more sophisticated miniature tracking devices (e.g., satellite tags) become available. [ABSTRACT FROM AUTHOR]

While marine hermit crabs are well known for being omnivorous filter feeders, less is known about the role they may play as active carrion scavengers in intertidal ecosystems. Prior studies have revealed that intertidal hermit crabs can be attracted to chemical cues from predated gastropods. Yet their attraction is usually assumed to be driven primarily by the availability of new shells rather than by food. We conducted field experiments to assess hermit crabs' potential role as generalist carrion scavengers on the California Coast, examining their speed of attraction and the size of the aggregations they formed in response to chemical cues from freshly smashed gastropods and mussels, both of which indicated available carrion. Compared to all other marine species, hermit crabs ( Pagurus samuelis, P. hirsutiusculus, and P. granosimanus) were the fastest to arrive at the provisioning sites. Hermit crabs also dominated the provisioning sites, accumulating in the largest numbers, with aggregations of up to 20 individuals, which outcompeted all other scavengers for carrion. Notably, hermit crabs arrived equally quickly for both smashed gastropod and mussel, even though the latter does not offer suitable shells for hermit crabs and even though the former only yields shell-related chemical cues over time frames longer than our experiments. These results thus suggest that shell availability is not the only, or even the primary, reason marine intertidal hermit crabs aggregate at carrion sites; they also aggregate to forage, thereby playing an important role as active carrion scavengers in intertidal ecosystems. [ABSTRACT FROM AUTHOR]

Sea otters are well-known tool users, employing objects such as rocks or shells to break open hard-shelled invertebrate prey. However, little is known about how the frequency of tool use varies among sea otter populations and the factors that drive these differences. We examined 17 years of observational data on prey capture and tool use from 8 sea otter populations ranging from southern California to the Aleutian Islands in Alaska. There were significant differences in the diets of these populations as well as variation in the frequency of tool use. Sea otters at Amchitka Island, Alaska, used tools on less than 1% of dives that resulted in the capture of prey compared with approximately 16% in Monterey, California. The percentage of individuals in the population that used tools ranged from 10% to 93%. In all populations, marine snails and thick-shelled bivalves were most likely to be associated with tool use, whereas soft-bodied prey items such as worms and sea stars were the least likely. The probability that a tool would be used on a given prey type varied across populations. The morphology of the prey item being handled and the prevalence of various types of prey in local diets were major ecological drivers of tool use: together they accounted for about 64% of the variation in tool-use frequency among populations. The remaining variation may be related to changes in the relative costs and benefits to an individual otter of learning to use tools effectively under differing ecological circumstances. [ABSTRACT FROM AUTHOR]

ABSTRACT Automated recorders and occupancy models can be used together to monitor population trends of multiple avian species across a large geographic region. Automated recorders are an attractive method for monitoring birds, because they leave a record that can be independently validated and multiple units can be programmed to repeatedly survey different locations at the same daily times. We assessed the use of automated recorders and single-species, single-season occupancy models to monitor common forest birds across a 5.4-million-ha region of northern California. Using a survey protocol of 5-minute recordings at 3 times of the morning repeated over 3 consecutive days at 453 sites, we detected 32 species at >10% of these sites. Five of these species (Steller's jay [ Cyanocitta stelleri], mountain chickadee [ Poecile gambeli], red-breasted nuthatch [ Sitta canadensis], dark-eyed junco [ Junco hyemalis], and western tanager [ Piranga ludoviciana]) were dominant with occupancies >0.5. We also modeled occupancy associations with elevation and canopy cover for brown creeper ( Certhia americana), MacGillivray's warbler ( Geothlypis tolmiei), and western tanager and found the environmental conditions at which occupancy was maximized differed by up to 399 m in elevation and 17.9% canopy cover for these species. Given a sampling effort of 100 new sites per year, we demonstrated 80% power ( α = 0.1) to detect occupancy declines as small as 2.5% per year over 20 years for the 32 most common species. The effective radius of automated recorder surveys was approximately 50 m. In a field test, surveys conducted concurrently using automated recorders and point counts yielded similar occupancy estimates despite differences in detection probability. Our results suggest that automated recorders, used alone or in conjunction with point counts, can provide a practical means of monitoring common forest birds across a large geographic area. © 2014 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Studies in pinniped whisker use have shown that their whiskers are extremely sensitive to tactile and hydrodynamic signals. While pinnipeds position their whiskers on to objects and have some control over their whisker protractions, it has always been thought that head movements are more responsible for whisker positioning than the movement of the whiskers themselves. This study uses ball balancing, a dynamic sensorimotor skill that is often used in human and robotic coordination studies, to promote sea lion whisker movements during the task. For the first time, using tracked video footage, we show that sea lion whisker movements respond quickly (26.70 ms) and mirror the movement of the ball, much more so than the head. We show that whisker asymmetry and spread are both altered to help sense and control the ball during balancing. We believe that by designing more dynamic sensorimotor tasks we can start to characterise the active nature of this specialised sensory system in pinnipeds. [ABSTRACT FROM AUTHOR]

The article focuses on a study related to captive husbandry and reproduction of Giant Horned Lizard Phrynosoma asio at Los Angeles Zoo and Botanical Gardens,California. Topics disused include gaining of weight of the lizard by feding larger and pre-killed crickets; lack of aggressive behavior in mixed gender and bachelor groups of the lizard; semi active behavior of the lizard during brumation and their soaking in in shallow water.

Direct effects of predators depend upon factors that can vary across seasons, including variations in the abundance and vulnerability of migrating prey. Past studies show conflicting results of whether puma ( Puma concolor (L., 1771)) feeding ecology varies among seasons. We employed GPS collars to study puma feeding ecology in a single-prey system with migratory black-tailed deer ( Odocoileus hemionus columbianus (Richardson, 1829)). We hypothesized that puma feeding ecology would vary based on changes in prey abundance and spatial distribution, as well as competition with scavengers and decomposers. Our results supported these hypotheses. Kill rates in number of ungulates/week were significantly higher in summer and autumn than in winter, likely owing to the increased availability and density of black-tailed deer fawns. The handling times of black-tailed deer ≥1 year old were significantly higher in winter than in spring, summer, or autumn. We speculated that reduced handling time in summer may have been influenced by black bear ( Ursus americanus Pallas, 1780) kleptoparasitism and the decomposition of kills. Pumas killed black-tailed deer at higher elevations in summer than in winter, spring, or autumn, and the elevations correlated significantly with seasonal elevations used by black-tailed deer, suggesting that pumas exhibited seasonal foraging behaviours and tracked prey availability in a system with migrating prey. [ABSTRACT FROM AUTHOR]

Background Minimal scientific information is available to inform public health policy on binge drinking prior to pregnancy detection. The nonhuman primate provides a valuable animal model for examining consequences to reproduction and offspring function that may result from this common pattern of alcohol abuse. Methods Adult female rhesus monkeys were dosed with 1.5 g/kg per day ethanol (EtOH) by gavage 2 d/wk beginning 7 months prior to mating and continuing to pregnancy detection at 19 to 20 days gestation. Postnatal evaluation of control ( n = 6) and EtOH-treated ( n = 4) infants included a neonatal neurobehavioral assessment, a visual paired comparison (cognitive) test at 35 days of age, and mother-infant interaction at 100 to 112 days of age. Results Alcohol-exposed neonates did not differ from controls in posture and reflex measures. Longer durations of visual fixation, suggesting slower visual processing, and greater novelty preference were seen in the alcohol group. At early weaning age, as infants spent more time away from their dams, more of the reunions between mother and infant were initiated by the mothers in the alcohol-exposed group, suggesting a more immature mother-infant interaction. Conclusions Intermittent high-dose alcohol exposure (binge drinking) discontinued at early pregnancy detection in rhesus monkey can result in altered behavioral function in the infant. Mediating effects on ovum, reproductive tract, and early embryo can be explored in this model. Studies of longer-term consequences in human populations and animal models are needed. [ABSTRACT FROM AUTHOR]

Ungulates impact woody species' growth and abundance but little is understood about the comparative impacts of different ungulate species on forest expansion in savanna environments. Replacement of native herbivore guilds with livestock [i.e., beef cattle ( Bos taurus)] has been hypothesized as a factor facilitating trembling aspen ( Populus tremuloides Michx.) encroachment into grasslands of the Northern Great Plains. We used a controlled herbivory study in the Parklands of western Canada to compare the impact of native ungulates and cattle on aspen saplings. Native ungulate treatments included a mixed species guild and sequences of herbivory by different ungulates [bison ( Bison bison subsp. bison), elk ( Cervus elaphus) then deer ( Odocoileus hemionus); or deer, elk, then bison]. Herbivory treatments were replicated in three pastures, within which sets of 40 marked aspen saplings (<1.8 m) were tracked along permanent transects at 2-week intervals, and compared to a non-grazed aspen stand. Stems were assessed for mortality and incremental damage (herbivory, leader breakage, stem abrasion and trampling). Final mortality was greater with exposure to any type of herbivore, but remained similar between ungulate treatments. However, among all treatments, the growth of aspen was highest with exposure only to cattle. Herbivory of aspen was attributed primarily to elk within the native ungulate treatments, with other forms of physical damage, and ultimately sapling mortality, associated with exposure to bison. Overall, these results indicate that native ungulates, specifically elk and bison, have more negative impacts on aspen saplings and provide evidence that native and domestic ungulates can have different functional effects on woody plant dynamics in savanna ecosystems. [ABSTRACT FROM AUTHOR]

We document development type for 33 species of benthic opisthobranch gastropods - 15 for the first time - collected mainly from the Southern California Bight. Fourteen of the newly examined species had planktotrophic development, while the dorid nudibranch Atagema alba had capsular metamorphic development, the first example of direct development in a non-dendrodoridid nudibranch known from the northeast Pacific Ocean. For the remaining 18 species our new data are either consistent with earlier determinations of development type, or confirm previous inferences. The new data also broaden geographic coverage for some species, and for the sacoglossan Stiliger fuscovittatus and the nudibranch Melibe leonina, suggest that egg size is inversely related to temperature. We correct the previous erroneous identification of nephrocysts as eyespots in the hatching planktotrophic larvae of the nudibranchs Tritonia festiva and Janolus fuscus. These results further highlight the predominance of planktotrophic development in benthic opisthobranchs from the northeast Pacific Ocean. [ABSTRACT FROM AUTHOR]

Coho salmon ( Oncorhynchus kisutch) of the Southern Oregon/Northern California Coast (SONCC) Evolutionarily Significant Unit (ESU) is federally listed as a threatened species. The Trinity River Restoration Program (TRRP) is rehabilitating the Trinity River to restore coho salmon (coho) and other salmonid populations. In order to evaluate the program's actions, several studies of movements and behavior of coho in the Trinity River were conducted from 2006 to 2009, including snorkel surveys and mark-recapture techniques based on Passive Integrated Transponder (PIT) tags, elastomer tags, and radio transmitters. Catch, recapture, and condition of natural sub-yearlings, along with site fidelity and emigration of hatchery-reared yearlings in rehabilitated and reference habitats, were studied. Location was important because coho were absent from the lower controlled and rehabilitated sites most of the time. However, rehabilitation did not have a significant effect on natural coho salmon at the site level. Apparent survival of radio-tagged, hatchery-reared yearling coho released downstream from Lewiston Dam was much lower in the first 10 km downstream from the release site than in other areas between Lewiston Dam and the Klamath River estuary. Estimated survival of yearling hatchery coho salmon per 100 km down to Blake's Riffle was estimated at 64 % over the distance of the 239 km study area. Migration primarily occurred at night in the upper Trinity River; however, as yearlings moved through the lower Trinity River towards the Klamath River, estuary nocturnal migration became less. Apparent survival was generally lowest in areas upstream from the North Fork of the Trinity River. [ABSTRACT FROM AUTHOR]

Adult Chinook salmon, Oncorhynchus tshawytscha, were ultrasonically tagged to monitor their movements past a tidally operated salinity control-gate structure that spans the width of Montezuma Slough, an important migration pathway for anadromous fish in the Sacramento Delta. The structure consists of a section of removable flashboards, three radial gates and a boat lock. Previous studies showed that movement through Montezuma Slough was delayed or hindered for many of the tagged salmon due to installation of the flashboards and the gate closures. Three gate configurations were tested as future mitigation options to facilitate salmon movement through the gates: full open with the boat lock closed; full operation with the boat lock open; and full operation with the boat lock closed. During October to November of 2001-2004, approximately 200 adult fall-run Chinook salmon were tagged annually and monitored for passage success during different gate configurations. Relative to the closed boat lock configuration, the full open configuration had a significantly higher passage rate in 2004 only, and a significantly shorter passage time in 2001. Relative to the closed boat lock configuration, the full operation with the boat lock open configuration was correlated with improved passage rates in 2 out of 4 years, with shorter passage times in 2001, and with longer passage times in 2002. The findings from this study suggest that the open boat lock can provide additional salmon passage at the salinity control gates, but that further multi-year studies using biotelemetry to track fish movement through Montezuma Slough should be addressed in future research. [ABSTRACT FROM AUTHOR]

Oncorhynchus mykiss are known to exhibit variable life histories expressed under genetic control or through the influence of the environment. Altered environmental conditions and the presence of large numbers of non-indigenous hatchery fish can affect the rate of anadromy observed in California's Central Valley O. mykiss. The lower Feather River, a large regulated river in Northern California, supports one of the largest populations of O. mykiss in the Central Valley, heavily subsidized by hatchery production. I examined downstream migratory behavior, movement rate, and success of natural-origin juveniles, natural-origin adults, and hatchery-origin fish using acoustic telemetry. I found that all three groups displayed a mix of migratory and non-migratory life histories. Hatchery-origin adults exhibited more migratory behavior (anadromy) than natural-origin juveniles and natural-origin adults, 41 %, 24 %, and 13 % respectively. Downstream migrants were also significantly larger than non-migratory fish. Migration timing was similar among the three groups, but natural-origin juveniles displayed the most rapid rate of movement. The relative success of each group was highest for fish migrating through the Sacramento-San Joaquin Delta to the Pacific Ocean. Hatchery-origin adults migrating through the lower Feather River showed the lowest relative success (33 %). The dominance of non-migratory life histories pattern among lower Feather River O. mykiss may be in response to the suitable habitat provided by hypolimnetic releases below dams and the current hydrological regime within the highly altered Sacramento-San Joaquin watershed. [ABSTRACT FROM AUTHOR]

We used acoustic telemetry to study the post-spawn movement of Oncorhynchus mykiss kelts released in April 2005 and 2006 from the Coleman National Fish Hatchery, Anderson, CA. Following release, O. mykiss kelts demonstrated both anadromous and non-anadromous life histories, with some fish alternating life history strategies between years. Anadromy was most common, characterized by a short-term residence near the release site, followed by sustained downstream emigration once initiated. O. mykiss kelts demonstrating anadromy arrived at the Golden Gate Bridge from April to mid-July. Repeat spawning migrations of anadromous O. mykiss kelts began from late-September through October of the year of release. High fidelity back to Battle Creek was observed, occurring from late-September through November. While most O. mykiss kelts were anadromous, at least 10 % remained in freshwater, or residualized. O. mykiss kelts that residualized demonstrated two distinct patterns of movement: 1) residency near the release location, and 2) potamodromy. Overall survival was high with 36 % and 48 % of O. mykiss kelts released making a repeat spawning migration and demonstrating iteroparity in 2005 and 2006, respectively. Increase in body lengths of O. mykiss kelts that returned to the Coleman NFH were significantly greater for anadromous fish, compared to fish that residualized, but survival was higher for fish that residualized. Release of hatchery O. mykiss kelts could result in both positive and negative genetic and ecological effects to hatchery- and naturally-producing salmonids. We believe the benefits of releasing O. mykiss kelts at the Coleman NFH, including increased numbers and size of fish in the recreational fishery and genetic and demographic benefits to the hatchery brood stock outweigh the limited risk to natural populations that would result from predation and competition of the relatively small number of O. mykiss kelts that resided in fresh water. [ABSTRACT FROM AUTHOR]

We conducted a 15 yr mark-resight study of branded California sea lions ( Zalophus californianus) at San Miguel Island, California, to estimate age-specific recruitment and natality of the population. We used the Schwarz and Stobo model to estimate sighting, survival, recruitment, timing of births, abundance, and age-specific natality from sighting histories of 1,276 parous females. The advantage of this approach was that the reproductive status of females did not have to be known for all females of reproductive age. Probability of recruitment into the reproductive population began at age 3 or 4, peaked between ages 5 and 7, and slowly declined. Age-specific natality was similar for ages 4-16 but declined after age 17, suggesting that reproductive senescence occurs in older females. The average annual natality for parous females 4-16 yr of age was 0.77 (SE = 0.03); natality declined to 0.56 (SE = 0.10) for parous females 17-21 yr of age. Natality for both age classes was reduced during El Niño conditions by 24% and 34%, respectively. In addition to reducing natality, El Niño events may result in a delay of recruitment if females experience El Niño conditions before they turn 4 yr of age. [ABSTRACT FROM AUTHOR]

This study provides the first in depth assessment of Sea Otter haul-out patterns in Elkhorn Slough, California and their relationship to environmental variables. Seasonal and daily water and air temperature fluctuations are a good predictor of Sea Otter haul-out patterns but are affected by the availability of haul-out sites at different tide levels. The cost effectiveness of this choice may be maximal at night because of lack of human disturbance. Southern Sea Otters (Enhydra lutris nereis) were observed during 50 bimonthly 24-h periods between August 2007 and July 2009 (n ?=? 1187 h) from a shore-based observation site located above a non-territorial male resting area on the north side of Moss Landing Harbor. We counted the number of Sea Otters in the area (both in the water and on land) at 30-min intervals. We also recorded tide height, and air and water temperature. Thirty-minute counts averaged 42 Sea Otters using the area (land and water) during the day and 66 at night. The average number of Sea Otters hauled out in the study area during the same haul-out event was 22, and the maximum number was 93. Sea Otters were observed hauled out on 70% of the days surveyed, and the proportion of Sea Otters hauled out was significantly higher at night. Higher numbers of Sea Otters on land was significantly correlated with lower air and water temperature, and with mid-range tide-heights. We speculate that haul-out behavior could play an important role in energy conservation; however, human-related traffic patterns in the area may negatively affect this energy conservation strategy. [ABSTRACT FROM AUTHOR]

Infestations of buildings by Argentine ants, Linepithema humile (Mayr), were monitored on the campus of the University of California, Los Angeles. Foraging ant activity peaked during the hotter months of the year. The mean monthly maximum temperature, but not rainfall, positively correlated with indoor infestation frequency. Neither garden size nor the predominant groundcover vegetation correlated with the number of foraging ants at baits within gardens. Although the number of foraging ants outside a building varied over 40-fold, ant density in gardens did not predict the likelihood of infestation within the building. Also, the type of vegetative groundcover employed did not predict infestation frequency. There was, however, a significant negative relationship between the size of the garden outside of a building and the number of infestations. Given the large foraging area of L. humile workers, buildings next to small gardens may be infested simply because they lie within the "normal"foraging area of a colony. The best predictor of which rooms were infested within buildings was the presence of a water source. Thus providing water for ant colonies outside and away from buildings may be one method of integrated pest management to reduce the proclivity of ants to infest structures. [ABSTRACT FROM AUTHOR]

The estimation of the strength of the interaction between species is key for understanding the organization of ecological communities. Although experimental and observational studies have estimated per capita interaction strength for individual consumers, no previous study has used such estimates for predicting the impact of a community of consumers on their prey in the field. Here we evaluate experimental estimates of per capita interaction strength and impact of consumers on prey by comparing our impact predictions with real-time series of prey abundance. We conducted aquarium experiments to estimate the effects of seven herbivore species on survival of early life stages (microscopic sporophytes) of the giant kelp, Macrocystis pyrifera. We also estimated the impact of a community of herbivores on a cohort of kelp sporophytes using time series (1983-2000) of herbivore abundance in the Point Loma, San Diego (California), kelp forest. The underlying assumption was that maximum herbivore impact on microscopic recruits is realized only after a disturbance removes the giant kelp plants and thus releases the recruits. Our model was successful in predicting the prevention of giant kelp recruitment, which occurred when the abundance of weak interactors increased above a threshold. These results indicate that experimental estimates of maximum per capita interaction strength can be used to predict strong consumer impacts. [ABSTRACT FROM AUTHOR]

Migratory salmon move nutrients both in and out of fresh waters during the different parts of their life cycle. We used a mass-balance approach to quantify recent changes in phosphorus (P) fluxes in six coastal California, USA, watersheds that have recently experienced dramatic decreases in salmon populations. As adults, semelparous Chinook () and coho () salmon imported 8.3 and 10.4 times more P from the ocean, respectively, than they exported as smolts, while iteroparous steelhead (i.e., sea-run rainbow trout, ) imported only 1.6 times more than they exported as kelts and smolts. Semelparous species whose life histories led them to import more nutrients were also the species whose populations decreased the most dramatically in California in recent years. In addition, the relationship between import and export was nonlinear, with export being proportionally more important at lower levels of import. This pattern was driven by two density-dependent processes - smolts were larger and disproportionately more abundant at lower spawner abundances. In fact, in four of our six streams we found evidence that salmon can drive net export of P at low abundance, evidence for the reversal of the 'conveyor belt' of nutrients. [ABSTRACT FROM AUTHOR]