Shorebird Conservation & Management

Contributed Oral Presentations

Contributed paper sessions will be available on-demand for the duration of the conference, then again at the conclusion of the conference.

 

Remote Sensing and Wildlife Management: Using Object Based Image Analysis for the Detection of Nesting Laughing Gulls
Benjamin F. Martini; Douglas A. Miller
Remote sensing has long been used to study wildlife, however manual methods of detecting wildlife in aerial imagery are often time consuming and prone to human error. Object based image analysis (OBIA) is a promising new technology that addresses both these issues through automation; however, it has not yet been extensively applied to wildlife surveys. We are using the OBIA software eCognition to detect the nests of a breeding colony of Laughing gulls (Leucophaeus atricilla) in Joco Marsh as part of an ongoing monitoring effort at the John F Kennedy International Airport conducted by the USDA. Our technique uses a combination of high resolution 4-band aerial imagery, LiDAR point cloud data, and land cover data as part of a feature extraction ruleset that classifies nest objects using the site, tone, shape, size, and association elements of image interpretation. Preliminary testing on a subset of the imagery revealed that our ruleset was successful at extracting 89% of the nests; however, it also had a high rate of errors of commission due to similarities between the nests and surrounding dead vegetation. After scaling up to the full set of imagery and fine tuning the ruleset using sublevel objects, we achieved a nest extraction rate of 97% while simultaneous reducing errors of commission from 50% to 34%. Although ruleset refinement remains ongoing, our results thus far demonstrate the value of this technology for detecting the nests of colonial nesting shorebirds like the laughing gull, as well as the value of OBIA techniques to wildlife sciences. This approach removes the need to manually search entire sets of imagery for nests and changes the user’s task to verifying output results and eliminating known errors of commission that the software is unable to differentiate from actual nests, a much more efficient and less error prone methodology.
Impacts of Extreme Disturbances at Wintering Areas on Piping Plover Survival and Migratory Connectivity
Kristen Ellis; Michael Anteau; Francesca Cuthbert; Cheri Gratto-Trevor; Joel Jorgensen; David Koons; David Newstead; Larkin Powell; Megan Ring; Mark Sherfy; Rose Swift; Dustin Toy
Effective conservation for listed migratory species requires understanding linkages between breeding and non-breeding areas. Environmental conditions away from breeding areas may have important impacts on demography of these species because most of the annual cycle occurs outside breeding areas. Piping Plovers (Charadrius melodus) are a federally-listed migratory species that periodically experience extreme environmental disturbances on wintering areas, including oil spills, toxic algal blooms, and hurricanes. Further, strong site fidelity of Piping Plovers at wintering areas emphasizes potential exposure to these disturbances. To evaluate how these disturbances impact survival and migratory connectivity, we implemented a seasonal multistate model (6 geographic areas representing 3 breeding and 3 wintering areas). We used capture and resighting data collected between 2002 – 2019 from Northern Great Plains USA, Southern Great Plains USA, and Prairie Canada breeding areas. Individuals from all breeding areas were more likely to migrate to the western Gulf of Mexico (Texas and Mexico) than to the eastern Gulf of Mexico or the Bahamas and Atlantic coast, although individuals from breeding areas mixed across all winter areas. Hurricanes and oil spills appeared to negatively influence wintering-season survival. Despite concerns over increased frequency of these extreme disturbances, we did not detect a negative trend in adult survival throughout our study period. Mixing among individuals at wintering areas may provide a buffering effect against impacts of extreme events on any one breeding sub-population. Our results moreover suggest that understanding migratory connectivity and linking seasonal threats to population dynamics can better inform conservation strategies for Piping Plovers.
Simulating Piping Plover Nesting Success As a Function of Predator and Plover Sensitivity to Human Disturbance
Samantha Smock; Alexander Cohen; Dr. Patrick Zollner
Piping plovers (Charadrius melodus) are federally threatened shorebirds that are heavily impacted by human disturbance on beaches. Predation is another significant disturbance that negatively affects plover chick survival. Both plovers and their predators are impacted by human presence, but it is less clear how the response of predators to humans will influence the survival of their prey. Humans may create predator-free space for plovers or they may attract predators increasing encounters with plovers. Individual-Based modeling (IBM) is a valuable tool for predicting population responses to complex circumstances like the consequences of the direct and indirect interactions of predator and prey species with disturbance caused by human recreation. We developed an IBM and used it to simulate the responses of plovers and two archetypically different plover predators to human recreation in beach environments. We investigated the effects of human density, beach configuration, and predator species that are either synanthropic or wary of humans upon plover chick survival, nest survival, and the flushing frequency of plover from predators and humans. We found that interactions between predators and humans do adversely impact plover chick survival. Higher human density was a major indicator of declining plover chick survival. Narrower beaches reduced nest survival, but beach width was not a strong predictor. Predator type was a major indicator of plover flushing rates in response to both predators and humans. We conclude that synanthropic predators may be more efficient at killing plover chicks because human activity drives them away from the beach environment less frequently than other predators. Overall, our results suggest that the interactive effect of predators and humans can impact plover nesting success. Beach managers should acknowledge the attractive or repellent effects that humans have on predators in creation of their management plans for plovers.

 

Contributed Oral Presentations
Location: Virtual Date: Time: -