Geology topics

F.J. Cuthbert

Publications and source records attributed to F.J. Cuthbert.

3 recordsLinked to original sources

USGS2010

Distribution of non-breeding great lakes piping plovers (Charadrius melodus) along Atlantic and Gulf of Mexico coastlines: Ten years of band sightings

In 1993, a mark-recapture effort was initiated to band annually all Great Lakes Piping Plover nesting adults and offspring. With voluntary reporting by observers, >430 sightings of 154 individually-marked Great Lakes banded birds were documented on the wintering grounds during 19952005. This paper reports non-breeding distribution and site-fidelity and identifies Critical Habitat units used by this population during the winter. Information obtained through banded bird sightings indicates that the winter range of Great Lakes Piping Plovers extends from North Carolina to Texas, and the Bahamas, with the majority (75%) of reported individuals wintering in Georgia and Florida. About 95% of sightings were near or within federally-designated winter Critical Habitat for Piping Plovers. Within season (52%) and between-year (62%) site fidelity was documented for resightings within 3.5 km of initial sighting. Although breeding pairs do not winter in close association, there is some evidence to suggest that offspring winter closer to the male rather than the female parent (P-value = 0.03), and adult males and females appear to exhibit latitudinal segregation (P-value < 0.001). Females reach the winter grounds before males, arriving in July and staying through April (???9 months) or 75% of the annual cycle. The study is the first to identify winter distribution for the Great Lakes Piping Plover population. The significant proportion of the annual cycle spent on the wintering grounds emphasizes the importance of habitat protection during the non-breeding season for this federally-listed population.

Waterbirds↗

USGS2000

Uncertain nest fates in songbird studies and variation in Mayfield estimation

Determining whether nesting attempts are successful can be difficult. Yet, current protocols for estimating nesting success do not address how uncertain nest fates should be handled. We examined the problem of nest-fate uncertainty as it relates to Mayfield estimation of nesting success and in analyses of factors that influence success. We used data from Minnesota to illustrate the potential effect of uncertain fate; 40% of Ovenbird (Seiurus aurocapillus; n = 127) nests and 30% of Least Flycatcher (Empidonax minimus; n = 144) nests had uncertain fates. How this uncertainty is incorporated into Mayfield estimates of success varied widely among researchers. In a survey of researchers who use the Mayfield method, 9 of 22 respondents (of 40 contacted) excluded nests with uncertain fate. Excluding uncertain fates is counter to how Mayfield first described his estimator and can result in severe downward bias. The remaining respondents (59%) included nests with uncertain fate but varied in how they terminated the exposure period. We developed a simulation model that calculated Mayfield estimates using different approaches and compared them with a known rate of nesting success. Magnitude of bias in Mayfield estimates varied considerably in our simulations. The approach with the least bias terminated exposure with the last observed active date for nests with uncertain fate, and with the midpoint between last observed active and first observed inactive dates for nests with known fate. In addition, information necessary to interpret and compare Mayfield estimates often is not reported. These values, including variance estimates and the period lengths used to estimate survival rates, should be reported with Mayfield estimates. Finally, nest fate is commonly used as a categorical variable in studies of factors affecting nesting success. In this approach, however, nests with uncertain fate must be excluded. An alternative approach is Cox regression, which incorporates nests with uncertain fate.

The Auk↗

USGS1997

Captive-rearing piping plovers: Developing techniques to augment wild populations

Techniques for captive-rearing and releasing piping plovers (Charadrius melodus) were developed using a surrogate species, killdeer (Charadrius vociferus). We compared captive- and parent-reared killdeer, and parent-reared piping plovers and determined that growth and behavior were similar. After surrogate trials determined that captive-rearing was feasible, we used the same methods to raise piping plover chicks from salvaged eggs. For captive-reared chick of both species, survival to fledging was higher than and behaviors similar to parent-reared chicks in the wild. Rearing techniques were fine-tuned, and ten piping plover fledglings were released to the wild. Based on our results, we developed recommendations for captive-rearing piping plovers using salvaged eggs to enhance productivity of small populations.

Michigan↗