The Mississippi Flyway midwinter population survey (MWS) indicates that American black ducks (Anas rubripes) have been rapidly declining for the last 10 years. We found a negative relationship between MWS and Ontario (Canada) midwinter counts for black ducks. Thus, as number of black ducks in the MWS decreased, Ontario midwinter counts increased. A shift in midwinter distribution of black ducks may be partly responsible for the decreasing trend in MWS counts. We recommend that midwinter black duck surveys be expanded to more sites in southern Canada and northeastern United States that currently are not sampled to better assess winter habitat use and improve the midwinter black‐duck population index.

The Eastern Population (EP) of greater sandhill cranes (Antigone canadensis tabida; cranes) is expanding in size and geographic range. Little information exists regarding the geographic extent of breeding, migration, and wintering ranges, migration chronology, or use of staging areas for cranes in the EP. To obtain these data, we attached solar global positioning system (GPS) platform transmitting terminals (PTTs) to 42 sandhill cranes and monitored daily locations from December 2009 through August 2014. On average, tagged cranes settled in summer areas during late‐March in Minnesota (7%), Wisconsin (29%), Michigan, USA (21%), and Ontario, Canada (38%) and arrived at their winter terminus beginning mid‐December in Indiana (15%), Kentucky (3%), Tennessee (45%), Georgia (5%), and Florida (32%). Cranes initiated spring migration beginning mid‐February to their respective summer areas on routes similar to those used during fall migration. Twenty‐five marked cranes returned to the same summer area after a second spring migration, of which 19 (76%) settled <3 km from the estimated mean center of the summer area of the previous year. During the 2010–2012 United States Fish and Wildlife Service (USFWS) Cooperative Fall Abundance Survey for cranes in the EP, we estimated that approximately 29–31% of cranes that summered in both Wisconsin and the Lower Peninsula of Michigan were not in areas included in the survey. The information we collected on crane movements provides insight into distribution and migration chronology that will aid in assessment of the current USFWS fall survey. In addition, information on specific use sites can assist state and federal managers to identify and protect key staging and winter areas particularly during current and future recreational harvest seasons. © 2017 The Wildlife Society.

Several surveys have documented the increasing population size and geographic distribution of Eastern Population greater sandhill cranes Grus canadensis tabida since the 1960s. Sport hunting of this population of sandhill cranes started in 2012 following the provisions of the Eastern Population Sandhill Crane Management Plan. However, there are currently no published estimates of Eastern Population sandhill crane survival rate that can be used to inform harvest management. As part of two studies of Eastern Population sandhill crane migration, we deployed solar-powered global positioning system platform transmitting terminals on Eastern Population sandhill cranes (n  =  42) at key concentration areas from 2009 to 2012. We estimated an annual survival rate for Eastern Population sandhill cranes from data resulting from monitoring these cranes by using the known-fates model in the MARK program. Estimated annual survival rate for adult Eastern Population sandhill cranes was 0.950 (95% confidence interval  =  0.885–0.979) during December 2009–August 2014. All fatalities (n  =  5) occurred after spring migration in late spring and early summer. We were unable to determine cause of death for crane fatalities in our study. Our survival rate estimate will be useful when combined with other population parameters such as the population index derived from the U.S. Fish and Wildlife Service fall survey, harvest, and recruitment rates to assess the effects of harvest on population size and trend and evaluate the effectiveness of management strategies.

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For migratory birds, wildlife managers can use the recruitment rate of young into an adult population to model population dynamics, manage harvest, or evaluate habitat. Few recruitment estimates exist for Eastern Population greater sandhill cranes Antigone canadensis tabida, and estimates are outdated and local in scale. Wildlife managers can use age ratios as an index to recruitment, and surveying at fall staging areas is efficient and cost effective. We created a systematic survey design for surveying eastern population crane age ratios in the Kankakee River valley (2013)(2014)(2015) in northwestern Indiana and the south-central counties of Michigan (2014Michigan ( -2015. Using logistic regression, we investigated factors that may cause spatial and temporal variation in age ratios, including flock size, timing within season, state, year, random vs. incidental survey routes, and observer. We stratified our selection of survey routes using a core area of high crane abundance, but do not recommend stratifying due to the added complexity and low utility. Observers determined the age of 53,371 cranes and found that the proportion of juveniles in Eastern Population crane flocks (p ¼ 0.113, 95% CI: 0.105 -0.122) was similar to previous estimates for the population. Proportion of juveniles was greater for south-central Michigan than for the Kankakee River valley, decreased with flock size, increased with lateness in the season, and varied among observers. Our design accounted for both ecological sources of variation in age ratios as well as nuisance variation. We recommend that future surveys use our design as part of a monitoring plan for Eastern Population cranes to support harvest management of the population and ensure that future survey results are comparable across years.