Spatial and temporal closures of anthropogenic activities are a common management strategy to increase waterfowl usage of an area. However, empirical evidence, specifically how individual waterfowl respond to disturbance, is lacking to support their efficacy. We exposed radiomarked mallards (Anas platyrhynchos) to walk-in, shooting, or no disturbance along the South Platte River corridor in Colorado, USA, from September to February during 2006-2007 and 2007-2008. Mallards exposed to shooting disturbance had greater mean flight distance after disturbance (FDAD) during September-November (4.58 km, 95% CI 5 3.55-5.62) than December-February (3.04 km, 95% CI 5 2.51-3.58) and were 35% and 17% greater than mean FDAD of mallards exposed to walk-in disturbance, respectively. Walk-in and shooting disturbance had a similar effect on return rates, and disturbed mallards had higher (0.09-0.41) movement probabilities away from and lower (0.15-0.20) probabilities of returning to treatment locations than controls. Probability of presence of disturbed mallards was 37% lower than controls during the daytime but was equal at night. Mallards exposed to walk-in (0.38 [95% CI 5 0.30-0.46]) and shooting (0.23 [95% CI 5 0.17-0.30] disturbance had low return rates the first afternoon after a disturbance compared to controls (0.71 [95% CI 5 0.65-0.77]). A high proportion of mallards exposed to walk-in (0.75 [95% CI 5 0.67-0.83]) and shooting (0.70 [95% CI 5 0.64-0.76]) disturbance returned to treatment locations in M 1 day. Managers may be able to more effectively manage disturbance regimes by 1) accounting for surrounding lands within ,10 km, especially lands within ,5 km, 2) being conscientious when establishing regulations that will affect levels of disturbance 1-2 days after a previous disturbance, and 3) considering shooting and walking disturbance equally for refuge design.

Abundance of temperate-nesting Canada geese (Branta canadensis) in Central Flyway east-tier states (ND, SD, NE, KS, OK, USA) increased since the 1970s. Hunting regulations were liberalized since the mid-1990s in these states to increase harvest and reduce abundance of local populations. Because 2 age classes, juvenile and adult, are typically classified when banding, most dead-recovery band analyses of Canada geese have only considered 2 age classes to estimate survival and recovery probabilities, despite a delayed breeding life history. We evaluated recovery distributions and survival and recovery probabilities of Canada goose age classes (i.e., juvenile [first year], subadult [second and third year], and adult [!fourth year]) among Central Flyway east-tier states relative to liberalized hunting regulations during 1990-2015. We also conducted simulations and evaluated bias in parameter estimates from 2-age-class dead-recovery models when a subadult age class was not modeled. Models including 3 age classes were more supported than models including only 2 age classes. Mean juvenile survival estimates among states from the top 2-age-class models were 9-50% greater than an equivalent 3-age-class model, whereas differences were less or negligible for adult survival (À4% to À1%), adult recovery (1-12%), and juvenile recovery (À3-6%). Geese were primarily recovered in the state they were banded (range among states ¼ 59-86%), and 91% of all recoveries occurred in the Central Flyway east-tier states. Recovery distributions of subadults were broader and more northward than adults and juveniles. Recovery estimates (Brownie parameterization) of subadults among states ( x ¼ 0.091 AE 0.039 [SE] to 0.116 AE 0.029) were also generally greater than adults (0.061 AE 0.030 to 0.104 AE 0.033) and juveniles (0.049 AE 0.026 to 0.132 AE 0.041). Survival estimates of adults (0.713 AE 0.103 to 0.748 AE 0.119) and subadults (0.621 AE 0.197 to 0.801 AE 0.154) exhibited some decrease through time concurrent with liberalized harvest regulations, but survival estimate of juveniles (0.492 AE 0.093 to 0.686 AE 0.164) increased or were stable. Of the 5 Central Flyway east-tier states, management actions to reduce local Canada goose populations were the most intensive in North Dakota and South Dakota, and these states had the greatest decrease in adult and subadult survival estimates. Our results provide some limited evidence that harvest regulations targeted at locally breeding Canada geese can affect their survival, have greatest effects when first implemented, and affect subadults from a broader spatial scale than adults and juveniles. More information is needed on how localized harvest regulations affect temperate-nesting Canada geese from other areas, particularly subadults and molt migrants, and, conversely, how such geese affect the ability to achieve management objectives at varying spatial scales. Lastly, to minimize bias when analyzing temperate-nesting Canada goose data, or other species with similar marking constraints and age-class ...

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Breeding populations of Canada geese (Branta canadensis) were established throughout western Colorado during 1955–1988 using geese transplanted from other areas. Subsequently, there has been no assessment of demographics and winter distributions on these local populations. Managers need this information to effectively manage breeding populations of Canada geese to provide publics with recreational opportunities and to reduce human‐goose conflicts in western Colorado, particularly for segments of internationally recognized populations with cooperative management plans. We conducted a band recovery study during 2000–2006 to assess demographics and winter distributions of Canada geese breeding in 7 subareas of western Colorado. Cooperators banded 19,189 geese during June and early July. We recaptured 5,185 of these geese 1–4 times during banding operations in subsequent years and most (97%) were recaptured in the subarea of banding the year after banding. We obtained 2,921 useable band recoveries through May 2007, and most (98%) recoveries were a result of either being shot or found dead during hunting season. Direct band recoveries (<1 year after banding) were recovered almost exclusively in Colorado (87%) and New Mexico (12%), and indirect band recoveries (≥1 year after banding) showed similar distribution (73% in Colorado and 16% in New Mexico). Geese in subareas of western Colorado had different recovery distributions, and contributed to 4 wintering concentrations of Canada geese in western and central Colorado and New Mexico. Annual survival probability for adult geese was 0.864 ± 0.012. The survival probability for juvenile geese was 0.503 ± 0.026, but we did find evidence that this estimate may be biased low. We used the band reporting probability of 0.525 ± 0.071 to derive harvest rates from band recovery rates. Harvest rate was 0.128 ± 0.018 for adult geese and 0.169 ± 0.024 for juvenile geese. Survival probability was lesser and harvest rate greater for the 3 western subareas (Western Plateau) compared to the 4 eastern subareas (Rocky Mountains). Our results suggest that Canada geese that breed and molt in western Colorado have high survival probability and are largely non‐migratory with some movement in winter from high to low elevation areas primarily in Colorado. To effectively manage the growing resident goose population in western Colorado, managers may need to increase harvest rates for these geese. © 2014 The Wildlife Society.

Atlantic brant (Branta bernicla hrota) are important game birds in the Atlantic Flyway and several long‐term monitoring data sets could assist with harvest management, including a count‐based survey and demographic data. Considering their relative strengths and weaknesses, integrated analysis to these data would likely improve harvest management, but tools for integration have not yet been developed. Managers currently use an aerial count survey on the wintering grounds, the mid‐winter survey, to set harvest regulations. We developed an integrated population model (IPM) for Atlantic brant that uses multiple data sources to simultaneously estimate population abundance, survival, and productivity. The IPM abundance estimates for data from 1975–2018 were less variable than annual mid‐winter survey counts or Lincoln estimates, presumably reflecting better accounting for observer error and incorporation of demographic estimates by the IPM. Posterior estimates of adult survival were high (0.77–0.87), and harvest rates of adults and juveniles were positively correlated with more liberal hunting regulations (i.e., hunting days and the daily bag limit). Productivity was variable, with the percent of juveniles in the winter population ranging from 1% to >40%. We found no evidence for environmental relationships with productivity. Using IPM‐predicted population abundances rather than mid‐winter survey counts alone would have meant fewer annual changes to hunting regulations since 2004. Use of the IPM could improve harvest management for Atlantic brant by providing the ability to predict abundance before annual hunting regulations are set, and by providing more stable hunting regulations, with fewer annual changes. © 2021 The Wildlife Society.