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The Cheadle Center at UCSB manages the North Campus Open Space (NCOS), which is a project that has restored 136 acres of upland and wetland habitats that existed before the area was converted into the Ocean Meadows Golf Course in the 1960s. The NCOS restoration project began in 2017 with a fine-scale grading of the site in order to recreate the salt marsh and use the excavated soil to rebuild the upland habitats to the southwest, which are now called the NCOS Mesa. In addition to re-establishing native biodiversity, a key goal of the restoration is to utilize the site as an educational, scientific, and recreational resource. This archived version of the December 2022 newsletter includes updates on how recent rainfall has influenced NCOS. The feature story focuses on bird diversity and efforts to sustain populations of rare and/or threatened breeding birds. Community photos include Hooded Merganser (Lophodytes cucullatus), Canada Goose (Branta canadensis), California Ebony Tarantula (Aphonopelma eutylenum), American Bittern (Botaurus lentiginosus), Northern Harrier (Circus hudsonius), and Cooper’s Hawk (Accipiter cooperii).

The Cheadle Center at UCSB manages the North Campus Open Space (NCOS), which is a project that has restored 136 acres of upland and wetland habitats that existed before the area was converted into the Ocean Meadows Golf Course in the 1960s. The NCOS restoration project began in 2017 with a fine-scale grading of the site in order to recreate the salt marsh and use the excavated soil to rebuild the upland habitats to the southwest, which are now called the NCOS Mesa. In addition to re-establishing native biodiversity, a key goal of the restoration is to utilize the site as an educational, scientific, and recreational resource. This archived version of the July 2022 newsletter includes updates on Kids in Nature field trips and the installation of new interpretive signs on Chumash ethnobotany and the importance of leashing dogs. The feature story focuses on breeding birds at NCOS. Community photos include Black-crowned Night Heron (Nycticorax nyctocorax), Barn Swallow (Hirundo rustica), Greater Yellowlegs (Tringa melanoleuca), Crotch’s bumblebee (Bombus crotchii), and Ventura Marsh Milk Vetch (Astragalus pycnostachyus var. lanosissimus).

The Cheadle Center at UCSB manages the North Campus Open Space (NCOS), which is a project that has restored 136 acres of upland and wetland habitats that existed before the area was converted into the Ocean Meadows Golf Course in the 1960s. The NCOS restoration project began in 2017 with a fine-scale grading of the site in order to recreate the salt marsh and use the excavated soil to rebuild the upland habitats to the southwest, which are now called the NCOS Mesa. In addition to re-establishing native biodiversity, a key goal of the restoration is to utilize the site as an educational, scientific, and recreational resource. This archived version of the January 2021 newsletter includes updates on planned future art installations, planting of annual wildflowers on the NCOS Mesa, and habitat management for Ventura Marsh Milk-vetch (Astragalus pycnostachyus var. lanosissimus) and Snowy Plover (Charadrius nivosus). The feature story focuses on the harmful effects of anticoagulant rodenticides on wildlife, including recently observed cases of predators with severe mange at NCOS. Community photos include Allen’s Hummingbird (Selasphorus sasin), Hermit Thrush (Catharus guttatus), and Black-crowned Night-heron (Nycticorax nycticorax).

Managing for the effects of climate change on species whose populations are currently imperiled requires detailed knowledge of the relationship between their demographic rates and climate variables. We sought this information for the West Coast breeding population of snowy plover (Charadrius nivosus), which was federally listed as threatened in 1993 due to substantial declines in the numbers of plovers breeding along the coast and in the number of sites occupied for breeding. Snowy plovers employ a serially polygamous breeding system in which the male typically tends chicks to independence. This unusual breeding system is favored by male‐biased sex ratios in local populations. As part of a multispecies study of the effect of climate change on population growth, we used mark–capture models to examine climate drivers of adult survival for 1219 snowy plovers banded at Monterey Bay over 38 years and known to overwinter on the surrounding north‐central California outer coast. Nonclimate variables, including sex and unmeasured annual mortality risks (e.g., predator abundance), were the primary factors affecting adult survival. However, there is evidence that cold weather, particularly extended cold snaps with daily low temperatures below 2°C and daily high temperatures below 10°C, decreases overwinter survival. Exceptionally cold winters had a particularly strong effect on adult female plovers, contributing to the male‐biased adult sex ratios. Future winter climate on the north‐central California coast is projected to be generally warmer with fewer and shorter cold snaps. Reduced mortality from cold winter weather may mitigate other threats faced by plovers, such as anthropogenically enhanced predator populations, habitat loss, and accelerated sea level rise, while altering the adult sex ratio and potentially shifting the evolutionary landscape maintaining the plover's unusual breeding system. [ABSTRACT FROM AUTHOR]

Snowy Plovers (Charadrius nivosus) are a species of conservation concern in Alabama, U.S.A., where the breeding population is small and restricted to just a few sites. Despite their listing, little research has been conducted on this species in the state. Snowy Plover nests (n = 119) were monitored at Bon Secour National Wildlife Refuge during 2015–2020. Just over half (53%) of all nests successfully hatched one or more chicks. Daily survival rates of Snowy Plover nests were estimated at the refuge using several temporal and environmental covariates. Constant daily survival rate was estimated at 0.97 (SE = 0.004, 95% CI = 0.97–0.98) and the probability of a nest surviving the 32-day incubation period was 0.42 (95% CI = 0.33–0.52). The top model in the nest survival analysis included year and site. This study is important in furthering our understanding of Snowy Plover populations in Alabama and can be used as a baseline for future analyses of nest survival. [ABSTRACT FROM AUTHOR]

The Cheadle Center at UCSB manages the North Campus Open Space (NCOS), which is a project that has restored 136 acres of upland and wetland habitats that existed before the area was converted into the Ocean Meadows Golf Course in the 1960s. The NCOS restoration project began in 2017 with a fine-scale grading of the site in order to recreate the salt marsh and use the excavated soil to rebuild the upland habitats to the southwest, which are now called the NCOS Mesa. In addition to re-establishing native biodiversity, a key goal of the restoration is to utilize the site as an educational, scientific, and recreational resource. This archived version of the October 2020 newsletter includes updates on Fall planting plans, a Burrowing Owl (Athene cunicularia) sighting and planned habitat enhancements, and Snowy Plover (Charadrius nivosus) habitat enhancements. The feature story focuses on Year 3 vegetation monitoring highlights.

The Cheadle Center at UCSB manages the North Campus Open Space (NCOS), which is a project that has restored 136 acres of upland and wetland habitats that existed before the area was converted into the Ocean Meadows Golf Course in the 1960s. The NCOS restoration project began in 2017 with a fine-scale grading of the site in order to recreate the salt marsh and use the excavated soil to rebuild the upland habitats to the southwest, which are now called the NCOS Mesa. In addition to re-establishing native biodiversity, a key goal of the restoration is to utilize the site as an educational, scientific, and recreational resource. This archived version of the December 2020 newsletter includes updates on the importance of not feeding wildlife, the presence of three burrowing owls (Athene cunicularia), Marsh Trail improvements, and planned removal of the Ellwood Marine Terminal tanks. The feature story focuses on bat acoustic monitoring, which has revealed a total of 8 species potentially using the space. Community photos include Hooded Merganser (Lophodytes cucullatus), Wilson’s Snipe (Gallinago delicata), Blue-gray Gnatcatcher (Poloptila caerulea), Barn Owl (Tyto alba), and White-tailed Kite (Elanus leucurus).

The Cheadle Center at UCSB manages the North Campus Open Space (NCOS), which is a project that has restored 136 acres of upland and wetland habitats that existed before the area was converted into the Ocean Meadows Golf Course in the 1960s. The NCOS restoration project began in 2017 with a fine-scale grading of the site in order to recreate the salt marsh and use the excavated soil to rebuild the upland habitats to the southwest, which are now called the NCOS Mesa. In addition to re-establishing native biodiversity, a key goal of the restoration is to utilize the site as an educational, scientific, and recreational resource. This archived version of the March 2020 newsletter includes newsletter includes updates on Visitor Plaza and Discovery Trail construction. The feature story focuses on the government grant funding that has made the project possible, including funding directed toward active transportation, endangered species protection, flood control, and other benefits of the project. Community photos include Cooper’s Hawk (Accipiter cooperii), Ruddy Duck (Oxyura jamaicensis), and Allen’s Hummingbird (Selasphorus sasin).

Abstract Managing for the effects of climate change on species whose populations are currently imperiled requires detailed knowledge of the relationship between their demographic rates and climate variables. We sought this information for the West Coast breeding population of snowy plover (Charadrius nivosus), which was federally listed as threatened in 1993 due to substantial declines in the numbers of plovers breeding along the coast and in the number of sites occupied for breeding. Snowy plovers employ a serially polygamous breeding system in which the male typically tends chicks to independence. This unusual breeding system is favored by male‐biased sex ratios in local populations. As part of a multispecies study of the effect of climate change on population growth, we used mark–capture models to examine climate drivers of adult survival for 1219 snowy plovers banded at Monterey Bay over 38 years and known to overwinter on the surrounding north‐central California outer coast. Nonclimate variables, including sex and unmeasured annual mortality risks (e.g., predator abundance), were the primary factors affecting adult survival. However, there is evidence that cold weather, particularly extended cold snaps with daily low temperatures below 2°C and daily high temperatures below 10°C, decreases overwinter survival. Exceptionally cold winters had a particularly strong effect on adult female plovers, contributing to the male‐biased adult sex ratios. Future winter climate on the north‐central California coast is projected to be generally warmer with fewer and shorter cold snaps. Reduced mortality from cold winter weather may mitigate other threats faced by plovers, such as anthropogenically enhanced predator populations, habitat loss, and accelerated sea level rise, while altering the adult sex ratio and potentially shifting the evolutionary landscape maintaining the plover's unusual breeding system.

The Cheadle Center at UCSB manages the North Campus Open Space (NCOS), which is a project that has restored 136 acres of upland and wetland habitats that existed before the area was converted into the Ocean Meadows Golf Course in the 1960s. The NCOS restoration project began in 2017 with a fine-scale grading of the site in order to recreate the salt marsh and use the excavated soil to rebuild the upland habitats to the southwest, which are now called the NCOS Mesa. In addition to re-establishing native biodiversity, a key goal of the restoration is to utilize the site as an educational, scientific, and recreational resource. This archived version of the October 2019 newsletter includes updates on Day of Caring volunteer planting progress, solar power on the barn, and September bird survey results. The feature story focuses on bird survey results at NCOS compared to Coal Oil Point Reserve. Community photos include American Avocet (Recurvirostra americana), Black-necked Stilt (Himantopus mexicanus), Lesser Nighthawk (Chordeiles acutipennis), and Carpenter Bee (Xylocopa sp.).

The Cheadle Center at UCSB manages the North Campus Open Space (NCOS), which is a project that has restored 136 acres of upland and wetland habitats that existed before the area was converted into the Ocean Meadows Golf Course in the 1960s. The NCOS restoration project began in 2017 with a fine-scale grading of the site in order to recreate the salt marsh and use the excavated soil to rebuild the upland habitats to the southwest, which are now called the NCOS Mesa. In addition to re-establishing native biodiversity, a key goal of the restoration is to utilize the site as an educational, scientific, and recreational resource. This archived version of the April 2019 newsletter includes updates on "Gator Barn” completion, signs of spring at NCOS, and the NCOS User Survey. Community photos include a Belted Kingfisher (Megaceryle alcyon) and Rock Wren (Salpinctes obsoletus).

The Cheadle Center at UCSB manages the North Campus Open Space (NCOS), which is a project that has restored 136 acres of upland and wetland habitats that existed before the area was converted into the Ocean Meadows Golf Course in the 1960s. The NCOS restoration project began in 2017 with a fine-scale grading of the site in order to recreate the salt marsh and use the excavated soil to rebuild the upland habitats to the southwest, which are now called the NCOS Mesa. In addition to re-establishing native biodiversity, a key goal of the restoration is to utilize the site as an educational, scientific, and recreational resource. This archived version of the May 2018 newsletter includes updates on snowy plovers and other birds using the habitat, as well as bridge installation. The feature story focuses on invasive plant control, which allows native plants to thrive and provides restoration experience for students. Community photos include Western Snowy Plovers (Charadrius nivosus), White-Faced Ibis (Plegadis chihi), Cliff Swallows (Petrochelidon pyrrhonota), and a juvenile Pacific Chorus Frog (Pseudacris regilla).

The Cheadle Center at UCSB manages the North Campus Open Space (NCOS), which is a project that has restored 136 acres of upland and wetland habitats that existed before the area was converted into the Ocean Meadows Golf Course in the 1960s. The NCOS restoration project began in 2017 with a fine-scale grading of the site in order to recreate the salt marsh and use the excavated soil to rebuild the upland habitats to the southwest, which are now called the NCOS Mesa. In addition to re-establishing native biodiversity, a key goal of the restoration is to utilize the site as an educational, scientific, and recreational resource. This archived version of the June 2017 newsletter includes updates on grading, bridge and boardwalk construction, and native plant propagation at the CCBER greenhouse. The feature story focuses on specific parts of the restoration intended to support native and/or special status species such as the tidewater goby (Eucyclogobius newberryi), western snowy plover (Charadrius nivosus nivosus), southern tarplant (Centromadia parryi ssp. australis), and various invertebrates, small mammals, reptiles and amphibians, and raptors. Community photos include red-tailed hawk (Buteo jamaicensis).

The habitat of beach-nesting birds often overlaps with areas heavily used for human recreation. Human activity has been linked to negative behavioral and reproductive consequences for shorebirds; therefore, it is important for managers to understand how to best mitigate disturbance. In Florida, there is concern that human disturbance negatively affects the state-threatened population of Snowy Plovers (Charadrius nivosus). We measured response probabilities and flight initiation distances (FIDs) of Snowy Plovers at sites experiencing a range of human use. Snowy Plovers responded at longer distances to pedestrians and dogs than to competitor and predator species, except for incubating birds which responded at longer distances to predators. At all distances below 50 m, plovers had a response probability of > 0.2 for pedestrians. Dogs induced such strong reactions at close distances that plovers always displaced before they came within 20 m. Brood-rearing plovers were more sensitive to anthropogenic disturbance than plovers engaged in other behaviors. Plovers at sites with high disturbance generally had lower FIDs than birds at sites with less disturbance. Our findings illustrate the importance of accounting for differences in disturbance regimes among sites when setting buffer distances, and for protecting brood-rearing areas in addition to nesting habitat. Due to the severity of responses prompted by dogs, managers should strongly consider dog prohibitions at sites with breeding Snowy Plovers, as reasonable buffers may not be adequate. [ABSTRACT FROM AUTHOR]

Abstract Social monogamy has evolved multiple times and is particularly common in birds. However, it is not well understood why some species live in long‐lasting monogamous partnerships while others change mates between breeding attempts. Here, we investigate mate fidelity in a sequential polygamous shorebird, the snowy plover (Charadrius nivosus), a species in which both males and females may have several breeding attempts within a breeding season with the same or different mates. Using 6 years of data from a well‐monitored population in Bahía de Ceuta, Mexico, we investigated predictors and fitness implications of mate fidelity both within and between years. We show that in order to maximize reproductive success within a season, individuals divorce after successful nesting and re‐mate with the same partner after nest failure. Therefore, divorced plovers, counterintuitively, achieve higher reproductive success than individuals that retain their mate. We also show that different mating decisions between sexes predict different breeding dispersal patterns. Taken together, our findings imply that divorce is an adaptive strategy to improve reproductive success in a stochastic environment. Understanding mate fidelity is important for the evolution of monogamy and polygamy, and these mating behaviors have implications for reproductive success and population productivity.

Abstract Background Marine and intertidal organisms face the rhythmic environmental changes induced by tides. The large amplitude of spring tides that occur around full and new moon may threaten nests of ground-nesting birds. These birds face a trade-off between ensuring nest safety from tidal flooding and nesting near the waterline to provide their newly hatched offspring with suitable foraging opportunities. The semi-lunar periodicity of spring tides may enable birds to schedule nest initiation adaptively, for example, by initiating nests around tidal peaks when the water line reaches the farthest into the intertidal habitat. We examined the impact of semi-lunar tidal changes on the phenology of nest flooding and nest initiation in Snowy Plovers (Charadrius nivosus) breeding at Bahía de Ceuta, a coastal wetland in Northwest Mexico. Results Using nest initiations and fates of 752 nests monitored over ten years we found that the laying season coincides with the lowest spring tides of the year and only 6% of all nests were flooded by tides. Tidal nest flooding varied substantially over time. First, flooding was the primary cause of nest failures in two of the ten seasons indicating high between-season stochasticity. Second, nests were flooded almost exclusively during the second half of the laying season. Third, nest flooding was associated with the semi-lunar spring tide cycle as nests initiated around spring tide had a lower risk of being flooded than nests initiated at other times. Following the spring tide rhythm, plovers appeared to adapt to this risk of flooding with nest initiation rates highest around spring tides and lowest around neap tides. Conclusions Snowy Plovers appear generally well adapted to the risk of nest flooding by spring tides. Our results are in line with other studies showing that intertidal organisms have evolved adaptive responses to predictable rhythmic tidal changes but these adaptations do not prevent occasional catastrophic losses caused by stochastic events.

The breeding season is a critical time for birds because the health and size of populations depends, in part, on it. Information on this aspect is needed in order to make appropriate management or conservation decisions. In order to evaluate the importance of coastal habitat in northwestern México as a breeding area for shorebirds, in May 2017, we made a visit to 12 sites, located in Baja California Sur (3), Sonora (3), Sinaloa (4), one shared by Baja California and Sonora (1) and another one by Sinaloa and Nayarit (1). We carried out two activities: coastal surveys and breeding evidence search. We reported nine potentially reproductive species and a hybrid (American x Black Oystercatchers). In total, we observe 6,960 shorebirds, where Black-necked Stilt (42%), American Avocet (32%) and American Oystercatcher (18.4%) numbers were noteworthy. The wetlands with the greatest abundance were Marismas Nacionales (35%), Huizache-Caimanero (13%), Yavaros-Moroncárit (12.5%) and Bahía de Tóbari (12%), all located on the mainland. For three species (American Oystercatcher, Snowy Plover and Wilson's Plover) the breeding individuals represent important fractions of their total populations. This research reaffirms the importance of northwestern México for the reproduction of resident shorebirds, some protected by the Mexican Government. [ABSTRACT FROM AUTHOR]

Delineating conservation units is a complex and often controversial process that is particularly challenging for highly vagile species. Here, we reassess population genetic structure and identify those populations of highest conservation value in the threatened snowy plover (Charadrius nivosus, Cassin, 1858), a partial migrant shorebird endemic to the Americas. We use four categories of genetic data—mitochondrial DNA (mtDNA), microsatellites, Z-linked and autosomal single nucleotide polymorphisms (SNPs)—to: (1) assess subspecies delineation and examine population structure (2) compare the sensitivity of the different types of genetic data to detect spatial genetic patterns, and (3) reconstruct demographic history of the populations analysed. Delineation of two traditionally recognised subspecies was broadly supported by all data. In addition, microsatellite and SNPs but not mtDNA supported the recognition of Caribbean snowy plovers (C. n. tenuirostris) and Floridian populations (eastern C. n. nivosus) as distinct genetic lineage and deme, respectively. Low migration rates estimated from autosomal SNPs (m < 0.03) reflect a general paucity of exchange between genetic lineages. In contrast, we detected strong unidirectional migration (m = 0.26) from the western into the eastern nivosus deme. Within western nivosus, we found no genetic differentiation between coastal Pacific and inland populations. The correlation between geographic and genetic distances was weak but significant for all genetic data sets. All demes showed signatures of bottlenecks occurring during the past 1000 years. We conclude that at least four snowy plover conservation units are warranted: in addition to subspecies nivosus and occidentalis, a third unit comprises the Caribbean tenuirostris lineage and a fourth unit the distinct eastern nivosus deme. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Field Ornithology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The relationship between the rate of predation and prey abundance is an important component of predator–prey dynamics. However, functional responses are less straightforward when multiple predators compete for shared prey. Interactions among competing predators can reduce or enhance effects of predation on prey populations. Because many avian populations experience high rates of nest predation, understanding the role of specific predators on nest mortality will lead to more informed conservation and management strategies which attempt to increase productivity by removing certain predators or managing habitat to limit their impact.Our goal was to evaluate effects of specific predators and the influence of nest abundance on nest mortality.We monitored snowy plover Charadrius nivosus nests across 7 years at two study areas in Utah, USA, with remote cameras. We modelled predator‐specific hazard rates for nest mortality in a Bayesian framework to assess relationships between competing predators and the role of nest abundance on predator‐specific hazard rates.We found that hazard rates for nest mortality by gulls Larus spp. decreased with increasing nest abundance, whereas nest mortality by foxes Vulpes spp. and ravens Corvus corax initially increased, indicating that dietary switching may occur when nests become more abundant. Nest mortalities of specific predators were often not independent and ranged between compensatory (e.g. mammalian mesopredators) and superadditive (e.g. avian predators) across the breeding season.The non‐independence between nest mortalities suggests that reductions in some predators may not translate to additive increases in overall nest success. Analyses of cause‐specific mortality are rarely applied to avian nests, but examination of interacting impacts among competing predators on nest survival may provide insight into specific drivers of avian population dynamics. A free Plain Language Summary can be found within the Supporting Information of this article. [ABSTRACT FROM AUTHOR]

Gamete size variation between the sexes is central to the concept of sex roles, however, to what extent gamete size variation within the sexes relates to sex role variation remains unclear. Comparative and theoretical studies suggest that, when clutch size is invariable, polyandry is linked to a reduction of egg size, while increased female-female competition for mates favors early breeding when females cannot monopolize multiple males. To understand whether and how breeding phenology, egg size, and mating behavior are related at the individual level, we studied the reproductive histories of 424 snowy plover females observed in the wild over a 15-year period. Egg size, but not polyandry, were highly repeatable for individual females. Consistent with theoretical predictions, we found that polyandrous females were the earliest breeders and that early clutches contained smaller eggs than clutches initiated later. Neither egg size nor mating behavior showed clear signs of an age-related deterioration, on the contrary, prior experience acquired either through age or local recruitment enabled females to nest early. Taken together, these results suggest that gamete size variation is not linked to mating behavior at the individual level, and, consequently, the adaptive potential of such variation appears to be limited., (© The Author(s) 2023. Published by Oxford University Press on behalf of The Society for the Study of Evolution (SSE).)

Social monogamy has evolved multiple times and is particularly common in birds. However, it is not well understood why some species live in long‐lasting monogamous partnerships while others change mates between breeding attempts. Here, we investigate mate fidelity in a sequential polygamous shorebird, the snowy plover (Charadrius nivosus), a species in which both males and females may have several breeding attempts within a breeding season with the same or different mates. Using 6 years of data from a well‐monitored population in Bahía de Ceuta, Mexico, we investigated predictors and fitness implications of mate fidelity both within and between years. We show that in order to maximize reproductive success within a season, individuals divorce after successful nesting and re‐mate with the same partner after nest failure. Therefore, divorced plovers, counterintuitively, achieve higher reproductive success than individuals that retain their mate. We also show that different mating decisions between sexes predict different breeding dispersal patterns. Taken together, our findings imply that divorce is an adaptive strategy to improve reproductive success in a stochastic environment. Understanding mate fidelity is important for the evolution of monogamy and polygamy, and these mating behaviors have implications for reproductive success and population productivity. [ABSTRACT FROM AUTHOR]

Interior snowy plover (Charadrius nivosus) population declines and deteriorating conditions throughout the Southern Great Plains (SGP) of Texas, New Mexico, and Oklahoma may be linked to environmental contaminants. Concentrations of V, As, Cd, Pb, and Se were quantified in breeding snowy plover blood, feathers (5th primary; P5), and potential prey (tiger beetles [Cicindela circumpicta and C. togata]). Se was (a) most commonly detected relative to other quantified elements and (b) frequently quantified at levels exceeding background or toxicity thresholds. Of samples greater than instrumentation detection limits, 98% of snowy plover blood and 22% of feather samples were greater than Se toxicity thresholds of 1 ppm ww for blood and 5 ppm dw for feathers (blood quantifiable range: 0.83-15.12 ppm; feathers quantifiable range: 1.90-27.47 ppm). Almost all tiger beetle Se concentrations were below reported invertebrate thresholds of 30 ppm dw (quantifiable range: 0.54-45.84 ppm). Snowy plover blood Se concentrations were related to sex, individual body condition, and local tiger beetle Se concentrations, while plover P5 Se concentrations were related to state, sex, and presence of body molt. Tiger beetle Se concentrations were related to individual study sites in Texas. These results provide some of the first evidence of Se exposure risk for interior snowy plovers nesting in saline lake and alkali flat environments of the SGP. Future efforts should focus upon specific Se uptake pathways during breeding and nonbreeding seasons, as snowy plovers breeding in the SGP appear to be exposed to Se throughout their annual cycle. [ABSTRACT FROM AUTHOR]

Adult sex ratio (ASR) is a central concept in population biology and a key factor in sexual selection, but why do most demographic models ignore sex biases? Vital rates often vary between the sexes and across life history, but their relative contributions to ASR variation remain poorly understood--an essential step to evaluate sex ratio theories in the wild and inform conservation. Here, we combine structured two-sex population models with individual-based mark-recapture data from an intensively monitored polygamous population of snowy plovers. We show that a strongly male-biased ASR (0.63) is primarily driven by sexspecific survival of juveniles rather than adults or dependent offspring. This finding provides empirical support for theories of unbiased sex allocation when sex differences in survival arise after the period of parental investment. Importantly, a conventional model ignoring sex biases significantly overestimated population viability. We suggest that sex-specific population models are essential to understand the population dynamics of sexual organisms: reproduction and population growth are most sensitive to perturbations in survival of the limiting sex. Overall, our study suggests that sex-biased early survival may contribute toward mating system evolution and population persistence, with implications for both sexual selection theory and biodiversity conservation. [ABSTRACT FROM AUTHOR]

Shorebird populations often rely on wetland habitats, for which they are considered important indicators of ecosystem health. Populations residing at low latitudes remain vastly understudied in comparison with populations from high latitudes. Here we use detailed behavioural and demographic observations during all life stages in combination with stage specific modelling to predict the population trajectory of a snowy plover ( Charadrius nivosus ) population at Bahía de Ceuta, Sinaloa, Mexico. In North America this shorebird is threatened, with many monitored populations declining. Our stochastic matrix model for the Ceuta population, which closely matched our field observations, suggests that the population is a sink with a 99.8% probability of going extinct within 25 years. Low apparent adult survival, which declined over time presumably because of poor reproductive success and/or permanent emigration in response to habitat degradation, had the largest impact on the population trajectory. We recommend urgent habitat management actions to address volatile water levels and hence increase reproductive success of this species at this important breeding site. Acknowledging the relative effects of flexible brood care on individual fitness and population dynamics presents an intriguing dilemma for conservation. We found that the flexible parental care system of snowy plovers affected chick survival: broods deserted by polyandrous females early after hatching had significantly lower survival than broods not deserted or those deserted late. Overall, deserting females raised fewer fledglings in this population than females that cared. Taken together, our study reveals unsustainable variation in local vital rate dynamics. To understand how this population contributes to regional source-sink dynamics, future research should evaluate the importance of immigration and emigration among neighbouring populations. [ABSTRACT FROM AUTHOR]

Understanding survival of precoclal chicks In the period Immediately following hatching has important conservation Implications because population growth Is often sensitive to post-hatching survival. We studied federally threatened Western Snowy Plover (Charadrius nivosus nivosus) broods at the northern limit of their range In coastal Oregon (n = 1,157) and Washington (n = 84) from 1991 to 2011 In an attempt to understand seasonal, annual, and spatial patterns of chick survival. In Oregon, plover chick survival Increased with age, varied between sites, and was greater at sites with predator management. The mean probability of surviving from hatch to fledging at 28 days of age In Oregon was 0.57 (95% Cl: 0.50, 0.63). In Washington, where predator management was not employed, we conducted separate analyses using Individually banded and unbanded chicks and results Indicated that survival generally Increased with chick age. The mean estimated probability of surviving from hatch to fledging at 28 days of age In Washington was 0.27 (95% Cl: 0.20, 0.35) for Individually banded chicks when perfect detection was assumed. This probability Increased to 0.67 (95% Cl: 0.41, 0.83) when we analyzed unbanded chicks and Included detection probability. Our findings confirm the Importance of considering age effects in the survival of Snowy Plover chicks and raise questions about the validity of assuming perfect detection of plover chicks during brood checks. This work also highlights the benefit of predator management on chick survival. [ABSTRACT FROM AUTHOR]

Conserving threatened and endangered species requires knowledge of breeding productivity and factors that cause variation in reproductive success. We summarized 13 years of lifetime reproductive success (LRS) data for 195 individually marked Snowy Plovers [Charadrius nivosus) breeding in Humboldt County, CA. Reproductive success was highly skewed among individuals with 13% of individuals (nmales= 12, nfemales= 14) producing =50% of fledglings; by contrast, 71% (n = 64) of males and 72% (n = 76) of females produced 2 or fewer during their lifetime. Variance in LRS was best explained by substrate (=100% of Akaike weight), with plovers breeding on gravel having significantly higher LRS compared to those on sandy substrates. Other measures of habitat quality, including use of nest exclosures, as well as corvid and human activity, were not significant predictors of LRS. Results indicated that enhancing the cryptic nature of substrates (for eggs and chicks) may be a productive means of increasing reproductive success in this threatened species. [ABSTRACT FROM AUTHOR]

The article discusses a research study about the influence of declining nest survival on the decline in the population of Snowy Plover at Great Salt Lake in Utah. Topics cited include the identification of nest survival, nesting substrate, the impact of predation, weather, and abandonment on daily nest survival rates, and the disadvantage of dikes as nesting habitat.

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Management to increase reproductive success is commonly used to aid recovery of threatened and endangered species. The Western Snowy Plover (Charadrius nivosus nivosus) breeds from coastal Washington, USA, to Baja California, Mexico, and in disjunct interior sites. The Pacific coast population is federally listed as Threatened; habitat loss and nest loss to a suite of terrestrial and avian predators are thought to be primary factors limiting population growth in this species. In coastal Oregon, USA, a consortium of state and federal management agencies deployed nest exclosures on active Snowy Plover nests, initiated a lethal predator management program, and conducted local-scale habitat management in an effort to boost local productivity. During 1990-2009, we monitored 1,951 Snowy Plover nests at 9 sites with varying treatments. We examined the effectiveness of 3 types of nest exclosures (large, small, and outfitted with electric wire), predator removal, and habitat management on nest survival. Habitat management to remove invasive grasses and provide more suitable nesting substrate more than doubled nest survival. Predator management or use of any of the 3 types of exclosures also affected nest survival. There appeared to be no additional benefit to using both approaches, but the biological relevance of these findings is unclear because of site differences in treatments applied. Importantly, these management techniques only affected nesting success; their effect on other contributions to population viability (e.g., fledging success) was not correlated with nesting success. This long-term study illustrates the short-term benefits and tradeoffs of using nest exclosures, predator management, and habitat restoration to improve nesting success. Although we gained broader insight into the relative efficacy of common management techniques to improve avian nesting success, we cannot yet determine how improved nest success contributes to population growth. [ABSTRACT FROM AUTHOR]

Life history theory predicts a tradeoff between reproductive effort and survival, which suggests that some management practices aimed at increasing productivity may compromise population growth. We analyzed a 10-year data set of 225 individually marked Snowy Plovers (Charadrius nivosus), a threatened shorebird, to determine whether individual reproductive effort was correlated with low apparent survival. Most adults resided in the population an average of 2 years (range: 1-10 years), during which females laid 3-60 eggs, and both males and females invested considerable time in incubation and brooding. Apparent survival varied annually and was higher for males than for females. Contrary to theory, we found no evidence that increased reproductive effort, either current or cumulative, compromised survival. Instead, apparent survival was correlated positively with incubation time, which may be related to either high-quality individuals having high reproductive rates and high survival or permanent emigration of failed breeders (who incubated for shorter intervals). Although our results suggest that some predator management practices (e.g., nest exclosures) aimed at increasing productivity will not compromise survival in a subsequent year, we caution that these same practices may have serious negative consequences for population growth if (1) reproductive effort does not translate into higher per capita fledging success and (2) direct mortality of adults results from the practice. [ABSTRACT FROM AUTHOR]

The article discusses a study on the nest survival and success of Snowy Plovers, Charadrius nivosus in Missouri River between South Dakota and Nebraska from 2008 to 2011. The study involves the use of logistic exposure approach to estimate the success of nesting and capture-recapture models in Program MARK to estimate the survival of the chicks and adults. It reveals that the results of the study was the same with the outcome for breeding of Piping Plovers, C. melodus in the same area.

We quantified changes in long-term Snowy Plover (Charadrius nivosus) survey counts and return rates, estimated current sex and age-specific apparent survival and encounter rates, and calculated recruitment thresholds needed to maintain a stable population in the Southern High Plains of Texas. Mean survey counts of adult Snowy Plovers decreased by 78% at one saline lake (from 80 adults/survey to 18 adults/survey) from 1999-2000 to 2008-2010 but remained consistent at an alternate lake (from 45 adults/survey to 41 adults/survey). Adult and juvenile return rates have similarly declined within this time frame by 25 and 62%, respectively. Long-term declines in return rates may be the result of increased mortality from declining habitat conditions either within or outside the breeding season. Current estimates of adult (65%) and juvenile (12%) apparent survival are lower than most other estimates for Snowy Plovers throughout their range. Current estimates of adult and juvenile apparent survival and return rates indicate 5.8-10.0 hatchlings per adult per year are needed to maintain the current population without immigration, a 3-5 fold increase in the past 10 years. [ABSTRACT FROM AUTHOR]

The article presents a study on nest survival and productivity of the Snowy Plover or Charadrius nivosus nesting on ocean-fronting beaches in northern California. It is said that plovers select sites that are different from the surrounding landscapes. Results show that daily nest survival is higher at the southern sites as compared to the northern sites where human and corvid activity is higher. Factors that affect plover reproductive success include land use and human and predator activity.

Snowy plovers ( Charadrius nivosus) are a species of conservation concern throughout North America and listed as a threatened species in Kansas. Management to minimize the effects of flooding and predation were implemented at Kansas breeding sites in the 1980s to encourage reproductive success. However, the effectiveness of those strategies and the effect of other variables that may influence nest survival have not been formally assessed. We used Program MARK to model the daily survival rate (DSR) of 317 snowy plover nests with 14 habitat- and management-related covariates to identify factors that influence nest survival and examine the efficacy of current management practices. In 2005 and 2006, we monitored nests and collected habitat data at the 2 known breeding sites in Kansas, Quivira National Wildlife Refuge (NWR) and Cheyenne Bottoms Wildlife Area (WA). Overall DSR was greater at Quivira NWR in 2006 (0.954) than at Cheyenne Bottoms WA (0.917) and Quivira NWR (0.942) in 2005. We developed 88 candidate models of which 4 competing models (ΔAIC c < 2) were identified. We selected the most parsimonious model ( K = 14, w i = 0.23) as the remaining 3 included covariates deemed biologically uninformative. This model included the effect of study site and year on a quadratic time trend, and included covariates quantifying nest age; precipitation; the proportion of gravel, rock, and vegetation at nests; occurrence within an electric fence and within 20 m of a road; occurrence on a human-constructed nest mound; and adult capture during incubation. We found a strong positive relationship between the use of nest mounds and DSR, and a strong negative relationship between precipitation and DSR. We also found a strong positive relationship between DSR and the proportion of vegetation at nest sites, the occurrence of a nest within an electric fence, and adult capture at a nest. We noted a strong negative relationship between DSR and occurrence within 20 m of a road. However, we found that DSR was not sensitive to the proportion of vegetation at a nest, occurrence within an electric fence or within 20 m of a road, and to adult capture at a nest in light of covariates quantifying precipitation and the use of nest mounds. We found weak support for a positive relationship between DSR, nest age, and the proportion of gravel and rock at nests. Our results indicate that large rainfall events are a major source of snowy plover nest loss in Kansas that can be mitigated by the construction of nest mounds. Limited influence of environmental variables found to influence nest survival at other breeding sites suggests that threats to snowy plover nest survival are site specific and managers should assess local sources of nest loss prior to implementing management strategies to improve reproductive success. © 2012 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Snowy plover ( Charadrius nivosus) populations have declined throughout their range, in part because of habitat degradation and poor nest success, making information regarding regionally specific nest site selection and spatial patterns important when considering habitat conservation and management guidelines. We determined nest site selection characteristics ( n = 180) and examined spatial patterns ( n = 215) of snowy plover nests in saline lakes in the Southern High Plains (SHP) of Texas. At 104 nests, we examined the influence of substrate type on nest temperatures and heat mitigation. Snowy plover nests were more likely to be found near an object, on pebble substrate, and with fewer plants than random sites. High use areas were generally located in areas with pebble substrate and on human-made or natural islands, berms, and peninsulas. Overall, nests placed on pebble substrate had lower temperatures during the day than nests placed on sand substrates. Nest placement on pebble substrate may be valuable to nesting snowy plovers, providing thermal advantages to incubating adults and depressing potentially high nest predation rates. Management guidelines for this region should emphasize the importance of addressing key elements of snowy plover nesting habitat including the presence of pebble substrate and reducing vegetation encroachment. © 2012 The Wildlife Society. [ABSTRACT FROM AUTHOR]

The article presents study on the population size of the shorebird Snowy Plovers, Charadrius nivosus, breeding in North America. Snowy Plovers or Charadrius nivosus is deemed one of the rarest shorebirds in the region. During 2007 and 2008, wetlands were surveyed and large wetland complexes sampled in Mexico and the U.S. An estimated population of 23,555 breeding Snowy Plovers were surveyed. Breeding sites in interior deserts and highlands and along the Pacific coast of Mexico were discovered.