Habitat Use and Reproductive Success of Western Snowy Plovers at New Nesting Areas Created for California Least Terns

2000 ◽  
Vol 64 (1) ◽  
pp. 24 ◽  
Author(s):  
Abby N. Powell ◽  
Christine L. Collier
Keyword(s):  
Reproductive Success ◽  
Habitat Use ◽  
Least Terns ◽  
Snowy Plovers ◽  
Western Snowy Plovers

Human dimensions of predator management for threatened Western Snowy Plovers

Wader Study ◽  
2021 ◽  
Vol 128 (1) ◽  
Author(s):  
Barbara Clucas
Keyword(s):  
Human Dimensions ◽  
Predator Management ◽  
Snowy Plovers ◽  
Western Snowy Plovers

scholarly journals Does vegetation change over 28 years affect habitat use and reproductive success?

The Auk ◽  
2019 ◽  
Vol 137 (1) ◽  
Author(s):  
Karolina Fierro-Calderón ◽  
Thomas E Martin
Keyword(s):  
Reproductive Success ◽  
Habitat Use ◽  
Nest Survival ◽  
Selection Function ◽  
Patch Use ◽  
Fitness Consequences ◽  
Long Term Changes ◽  
Changes Over Time ◽  
Over Time

Abstract Individuals should prefer and use habitats that confer high fitness, but habitat use is not always adaptive. Vegetation in natural landscapes changes gradually and the ability of species to adaptively adjust their habitat use to long-term changes is largely unstudied. We studied nest patch and territory use over 28 yr in Orange-crowned Warblers (Oreothlypis celata) in a system that has undergone natural long-term changes in vegetation. Abundance of maple (Acer grandidentatum), its preferred nesting habitat, gradually declined from 1987 to 2015. We examined whether habitat use and its fitness consequences changed as the availability of preferred habitat decreased. We used resource selection function models to determine changes over time in the probability of using a nest patch given available patches, and the probability of using a territory given available territories. We estimated nest survival to evaluate changes over time in the fitness consequences of nest patch use. We also compared habitat use (nest patch and territory) and fitness (nest survival) between areas with naturally reduced abundance of maple and experimentally increased abundance of maple (fenced areas). Nest patch use depended on maple abundance and did not change drastically across 28 yr, even though the availability of preferred maple patches decreased over time. In contrast, nest survival tended to decrease over time. We did not see differences in nest patch use and nest survival between unfenced and fenced areas, unlike territory use, which increased with the abundance of maple in fenced areas and decreased in unfenced areas. Our study depicts one example of relatively unchanged habitat use in the face of decreased availability of preferred vegetation across years, with a resulting decrease in reproductive success. Investigating changes in habitat use and fitness consequences for animals exposed to long-term habitat change is necessary to understand adaptive behavioral responses.

scholarly journals Making the best of a bad job? Chick mortality and flexible female brood care in Snowy Plovers

2019 ◽  
Author(s):  
Krisztina Kupán ◽  
Tamás Székely ◽  
Medardo Cruz-López ◽  
Keeley Seymour ◽  
Clemens Küpper
Keyword(s):  
Reproductive Success ◽  
Dynamic Modelling ◽  
Extended Period ◽  
Brood Care ◽  
Modelling Framework ◽  
Mating Opportunities ◽  
Breeding Attempt ◽  
Snowy Plover ◽  
Snowy Plovers ◽  
Female Brood

AbstractOffspring desertion represents a trade-off between current and future reproductive success. Its timing is crucial as the termination of parental care has profound consequences for the fitness of the parents and their offspring. However, the decision process involved with termination of care is still poorly understood. Snowy Plovers Charadrius nivosus show highly flexible brood care with females either deserting the brood early or providing care for an extended period. Deserting females often quickly remate and start a new breeding attempt. Using a dynamic modelling framework, we investigated the decision-making process for continuation or termination of care by females over a seven-year period. The length of female care increased over the season likely reflecting lower re-mating opportunities for deserting females late in the season. Present brood size, assessed daily during the brood care period, was strongly related to the length of female care: females were more likely to stay and care for larger than for smaller broods. Chick death and desertion frequently coincided, suggesting that poor offspring condition served as a trigger for female desertion. Overall, deserting females had a similar number of fledglings to caring females. This suggests that for many females, desertion was not a strategy to escape the shackles of monogamy and secure higher reproductive success through sequential polygamy. Rather, most deserting females made the best of a bad job when conditions were poor and their continued presence did not make a difference for the survival of their young. We conclude that when making the decision to continue or terminate care, Snowy Plover females monitor the condition of their offspring closely and adjust their care flexibly to the value and needs of their young.

scholarly journals Factors influencing the abundance of wintering western snowy plovers at Crown Memorial State Beach

2021 ◽  
Vol 107 (3) ◽  
pp. 249-259
Author(s):  
David L. Riensche
Keyword(s):  
Prey Availability ◽  
Habitat Choice ◽  
Protection Zone ◽  
The Public ◽  
Nonbreeding Season ◽  
Significant Difference ◽  
Food Shortages ◽  
Snowy Plovers ◽  
Shorebird Habitat ◽  
Western Snowy Plovers

Survival during the nonbreeding season, when mortality from food shortages and raptor predation is highest, influences shorebird population growth. These selection pressures, as well as anthropogenic influences, can shape wintering shorebird habitat use patterns. The western snowy plover (Charadrius alexandrinus nivosus) is a small shorebird that uses sand-spits, dune-backed beaches, open areas around estuaries for foraging and roosting. The Pacific Coast population of western snowy plovers is listed as a federally threatened species and a California Species of Special Concern. Previous studies suggest humans, dogs and corvids are sources of disturbance to plovers on public beaches. During 2014 to 2019, these disturbance factors were examined at Robert W. Crown Memorial State Beach in Alameda, California. In decreasing order of impact, the beach using public, corvids, and dogs were found to be the major stressors to over wintering plovers. Both the public and corvids respectively, resulted in disturbance and avoidance behaviors by plovers nearly 40% of the time. In 2015, the District created the Plover Protection Zone (PPZ) by installing symbolic fencing, signage, and establishing a volunteer team to monitor plovers and educate the public. In 2016, the potential prey abundance within the plover protection zone and areas directly north and south were examined using core samples and sticky traps. Statistical analysis showed a significant difference in the amount of macro-invertebrate prey available in the area used by the plovers as compared to other locations. Habitat choice and prey availability are vital to wintering shorebird. During this study, the wintering population of western snowy plovers increased from six to over 54 individuals.

Arrival times, laying dates, and reproductive success of Snowy Plovers in two habitats in coastal northern California

2010 ◽  
Vol 81 (4) ◽  
pp. 349-360 ◽  
Author(s):  
Mark A. Colwell ◽  
Noah S. Burrell ◽  
Michael A. Hardy ◽  
Kimiko Kayano ◽  
Jordan J. Muir ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Northern California ◽  
Arrival Times ◽  
Snowy Plovers

Effects of Management Strategies on the Reproductive Success of Least Terns on Dredge Spoil in Georgia

2007 ◽  
Vol 6 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Kathryn A. Spear ◽  
Sara H. Schweitzer ◽  
Robin Goodloe ◽  
Deborah C. Harris
Keyword(s):  
Reproductive Success ◽  
Management Strategies ◽  
Least Terns ◽  
Dredge Spoil

scholarly journals Using Decision Science for Monitoring Threatened Western Snowy Plovers to Inform Recovery

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 569
Author(s):  
Bruce G. Marcot ◽  
James E. Lyons ◽  
Daniel C. Elbert ◽  
Laura Todd
Keyword(s):  
Performance Measures ◽  
Risk Attitude ◽  
Cost Effective ◽  
Monitoring Methods ◽  
Optimal Decisions ◽  
The Us ◽  
Fish And Wildlife Service ◽  
Snowy Plovers ◽  
On The Road ◽  
Western Snowy Plovers

Western Snowy Plovers (Charadrius nivosus nivosus) are federally listed under the US Endangered Species Act as Threatened. They occur along the US Pacific coastline and are threatened by habitat loss and destruction and excessive levels of predation and human disturbance. Populations have been monitored since the 1970s for distribution, reproduction, and survival. Since the species was federally listed in 1993 and a recovery plan was approved under the US Fish and Wildlife Service in 2007, recovery actions have resulted in growing populations with increased presence at breeding and wintering sites throughout their Pacific Coast range. This success has created logistical challenges related to monitoring a recovering species and a need for identifying and instituting the best monitoring approach given recovery goals, budgets, and the likelihood of monitoring success. We devised and implemented a structured decision analysis to evaluate nine alternative monitoring strategies. The analysis included inviting plover biologists involved in monitoring to score each strategy according to a suite of performance measures. Using multi-attribute utility theory, we combined scores across the performance measures for each monitoring strategy, and applied weighted utility values to show the implications of tradeoffs and find optimal decisions. We evaluated four scenarios for weighting the monitoring objectives and how risk attitude affects optimal decisions. This resulted in identifying six strategies that best meet recovery needs and were Pareto optimal for cost-effective monitoring. Results were presented to the US Fish and Wildlife Service, responsible for monitoring as well as for consideration to ensure consistent monitoring methods across the species’ range. Our use of structured decision-making can be applied to cases of other species once imperiled but now on the road to recovery.

Monitoring Western Snowy Plover Nests with Remote Surveillance Systems in San Francisco Bay, California

2012 ◽  
Vol 3 (1) ◽  
pp. 123-132 ◽  
Author(s):  
Scott A. Demers ◽  
Catilin W. Robinson-Nilsen
Keyword(s):  
San Francisco ◽  
Human Disturbance ◽  
Surveillance System ◽  
Management Practices ◽  
San Francisco Bay ◽  
Behavioral Studies ◽  
Snowy Plover ◽  
Snowy Plovers ◽  
Nest Predators ◽  
Western Snowy Plovers

Abstract The western snowy plover Charadrius nivosus nivosus is listed as threatened under the U.S. Endangered Species Act of 1973 due to long-term population declines related, in part, to nest predation and human disturbance. In San Francisco Bay, California, numbers of predators of western snowy plovers and the potential for recreation-based human disturbances have increased during the past few decades and will likely increase for the foreseeable future. In an attempt to increase the reproductive success of western snowy plovers, managers have dedicated considerable resources to management practices including predator removal and habitat enhancement projects in San Francisco Bay. The unequivocal identification of western snowy plover nest predators and information regarding the behavioral responses of nesting plovers to human disturbance would inform management practices for this species. Therefore, we examined the efficacy of using a digital video surveillance system to identify nest predators of western snowy plovers in former salt evaporation ponds in San Francisco Bay and to assess its potential for use in behavioral studies. This system was designed to minimize disturbance to nesting plovers and limit predator bias at breeding sites that had little or no cover to camouflage or protect the equipment. The system included a small camera with infrared lights placed approximately 20 m from nests and a continuously operating recording unit and power supply that was positioned up to 300 m from nests. The system could be deployed within 20 min, run continuously for up to 5 d, and data could be retrieved without disturbing nesting birds. During a 2-y study period, we recorded six species depredating plover eggs and chicks: red-tailed hawk Buteo jamaicensis, common raven Corvus corax, California gull Larus californicus, northern harrier Circus cyaneus, ruddy turnstone Arenaria interpres, and gray fox Urocyon cinereoargenteus. Our results suggest that this surveillance system was effective for identifying western snowy plover nest predators, and the presence of the camera did not influence nesting success of monitored nests. This system could be integrated into conservation programs intended to improve reproductive success of this species and could be useful for conducting behavioral studies of western snowy plovers and other species.

Sign in / Sign up

Export Citation Format

Share Document