Recent detections of large gatherings of Whooping Cranes suggest that flock sizes may be increasing at some stopover locations during both the spring and fall migrations. We used the public sightings database managed by the US Fish and Wildlife Service from 1942 to 2018 to analyze data for long-term trends in group size. We then examined the spatial distribution of large groups to explore potential explanations for these occurrences. The proportion of Whooping Crane groups comprised of 2, 3, and 4-6 individuals showed no trend over time. However, observations of individuals showed a declining trend and groups of 7-9 and !10 showed an increasing trend. The frequency of groups observed exceeding 5 and 10 individuals were better predicted by survey year than by Whooping Crane population size suggesting that an increasing population is not the sole driver of large group occurrences. Our results indicate that large groups occur disproportionately within the 50% migration corridor, at staging areas within the first or last 20-30% of the migration path, and near conservation-managed wetlands, particularly within the southern Great Plains. Our results suggest that in addition to population growth, conspecific attraction, location within the migration corridor, and habitat loss may be contributing to large group occurrences. Further research is needed to determine the degree to which these factors influence large Whooping Crane group formation. The gathering of large numbers of Whooping Cranes in a single location presents potential tradeoffs for the species. While increasing group sizes may improve threat detection and avoidance, it comes at a cost of increased disease and mass mortality risk.

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The Central Platte River Valley (CPRV) is a unique and biologically important ecoregion, and several studies have conducted localized herpetofauna species inventories. However, there has been significantly less effort to quantify the habitat associations or activity patterns of these species. Habitat associations and activity patterns vary regionally and provide important information for ecosystem management. We deployed a total of 38 traps of 5 different types (pitfall, funnel, hoop, box, and coverboard) across 11 sites (7 terrestrial, 4 aquatic) for an 8-week period in June and July 2019. Our exploratory analyses used generalized linear models with a quasibinomial distribution to examine associations between herpetofauna abundance (captures per trap night) and habitat characteristics controlling for trap type. Habitat characteristics assessed included distance to nearest woodland, distance to nearest standing water, vegetation species richness, soil texture, and vegetative cover in addition to others. We also evaluated activity patterns weekly across the study period. The two most abundant species demonstrated divergent distributional patterns, Northern Prairie Skinks were only absent from two of the driest terrestrial sites, while the Six-lined Racerunners were locally abundant at just three sites with significant bare ground and sandy soils. We documented a Cope’s Gray Treefrog at a site with little woody cover in which the species had not been previously observed, suggesting it may be increasingly widespread regionally. We also detected relatively widespread juvenile anuran dispersal at multiple terrestrial sites a considerable distance from standing water. Our results provide a preliminary examination of habitat associations and summer activity patterns for herpetofauna in the CPRV that can be used to inform conservation efforts and further studies of this system.

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