Addressing threats to landscape sustainability on the Southern High Plains using land-use
\nand climate change scenarios to model agricultural bioenergy available for the midcontinent population of Sandhill cranes (Antigone canadensis)

Sandhill cranes (Antigone canadensis) of the mid-continent population (MCP) overwinter in central North America with ~80% visiting regions within the Southern High Plains (SHP) ecoregion of west Texas and eastern New Mexico. The MCP consists of greater (A.c. tabida) and lesser (A.c. canadensis) subspecies, which cooccur along the eastern escarpment of the SHP but otherwise remain generally segregated with lessers dominating the western region and greaters found primarily east of the Texas panhandle. Greater sandhill cranes comprise approximately one third of the population overall and tend to be east of most lessers which comprise the other two-thirds. Fine-scale winter metrics may provide insight for managers on how to achieve a proportionate subspecies harvest and maintain population objectives. My objectives for this chapter were to model home ranges of sandhill cranes (n=100; 1998−2004, 2011−2018) using one of two movement models, Brownian Bridge (BBMM) and dynamic (dBBMM) and use home range models to estimate annual philopatry of each crane. I successfully created 166 BBMM winter home ranges from 72 cranes and compared 93 consecutive crane-winters of 53 of those cranes for philopatric behavior estimates. Home range average size across remaining (n = 123) BBMM crane-winters was 4,138 km2 (±464; SD = 3,571.1). Home range overlap for pairs of consecutive years averaged 36% (SD = 28.7%, 0−100%). Three cranes showed high philopatry (>80% return overlap) when I calculated the amount of the first winter home range covered by all (2−3) consecutive winters, while 12 of the 27 multi-year returning cranes had no proportion of the first recorded winter covered by all of their following years. Home range sizes were not different among subspecies but varied widely across multiple winters and across the span of a sandhill crane tracking lifetime. Surface wetness extent and home range size were weakly negatively correlated (r = -0.44), suggesting sandhill cranes flew (~30+ km) to new areas more frequently when fewer wetlands were inundated and wetland extents were smaller and shorter-lived than years of high wetland extent. This behavior was variable across the population, and some cranes exhibited the opposite response to diminished wetlands by flying to many roosts creating larger home ranges. These results add to our understanding of sandhill crane response to diminished wetland availability.
\nThe MCP consists of greater (A.c. tabida) and lesser (A.c. canadensis) subspecies described as 4 breeding affiliations, Western Alaska-Siberia (WAS), Northern Canada-Nunavut (NCN), West-central Canada-Alaska (WCA) and East-central Canada-Minnesota (ECM). Using a sample of satellite-tagged cranes captured in Nebraska (1998−2014) and west Texas (2014−2018), I located and described Areas of Importance (n = 30, AOI, local landscape containing daily resources) for the MCP across its winter range (south of 36°N), with 57% located on the SHP. I compared breeding affiliation composition at AOIs to the overall population and found that AOIs (n = 7) along the eastern escarpment of the SHP had subspecies and breeding affiliation compositions similar to the entire population. Across the remaining AOIs, compositions differed greatly, ranging from only WAS lessers in all western AOIs to a blend of greaters and lessers from NCN and ECM or WCA breeding affiliations. Lessers that visited western AOIs likely encountered greaters from the Rocky Mountain Population, but none from the MCP ever ventured west of the SHP. I found several strong correlations between occupancy and location metrics including average duration and total visits, with both distance to nearest AOI and latitude. Areas of Importance in the SHP generally had greatest number of cranes and visits for shortest durations, while central and southern AOIs had fewer visits by fewer cranes but for a longer average duration. Northern AOIs were clustered relatively close in proximity, and cranes moved easily among AOIs more often than cranes at isolated AOIs. Sandhill cranes of the MCP can occupy and adapt to isolated AOIs, making infrequent roost changes throughout winter, and in another winter to clusters of AOIs, making frequent roost changes throughout winter. 
\nTelemetry has been an indispensable tool in wildlife studies for over 60 years and in crane (Antigone, Grus) conservation for over 30 years. Discoveries in migratory pathways, population distribution, time/space-specific habitat use, and movement patterns were made possible from satellite telemetry, using both the Argos Doppler and GPS location satellite systems. For my study on the winter ecology of the mid-continent population (MCP) I deployed two types of solar Platform Transmitter Terminals (PTT) on 35 sandhill cranes (Antigone canadensis) from 17 December 2014 – 4 April 2018: 18-gram Argos PTT and 22-gram Argos/GPS PTT. PTTs were purchased in 5 separate batches from 2 manufacturers, 1 Argos group (‘A’) from North Star and 4 Argos/GPS groups (‘B’−‘E’) from Microwave Telemetry, Inc across 2 calendar years. Error rates for each purchase group changed little as PTTs aged, even after >3 years for the first-year capture cohort. However, GPS groups ‘D’ and ‘E’ which were purchased >1 year after the first purchase groups, had the lowest first and second-year removal rates by one order of magnitude, suggesting manufacturing factors (engineering and components) that I could not account for may have contributed to this difference. I calculated unweighted message filter rates between the GPS dataset (n = 31) and the Argos dataset (n = 4) and found 26% and 52% of year-round location messages were removed, respectively. Twenty-seven cranes (77%) survived the study period with operating PTTs, including all 4 that wore Argos PTTs. For 8 crane/PTT units that did not live to the study end, I postulated on each scenario through information gleaned from direct observations (e.g., hunters) and location data. One crane was reported harvested, 1 PTT battery slowly lost power and died, 3 are likely incidences of the crane dying, and 2 have unknown causes of data cessation. Both types of transmitters were successful tools in collecting locations of a species that migrates across continents. GPS-equipped units are superior to Argos-only units at reducing uncertainty of error but cost more, forcing researchers to choice between affordability (and increasing sample size) and low uncertainty. 
\nThe Southern High Plains (SHP) are a critical winter range for much of the ~890,000 mid-continent sandhill cranes (Antigone canadensis), providing wetlands for roosting drinking and grain crops for foraging. Corn and sorghum grown in the region feed sandhill cranes the vast majority of their winter diet. Climate change directly and indirectly effects the suitability of wetlands by changing the water level, salinity, and overall wetness and crop forage by effecting metabolic nutrition, yield, and plant survival. Irrigation has been widely used to mitigate precipitation deficits, especially for corn. Projections from climate, agriculture, and hydrological models combined suggested the SHP will be less arable from higher temperatures and lower precipitation. I selected a suite of output variables from projection models to use as input for a bioenergetic carrying capacity model estimate. Selecting only sorghum and corn juxtaposed to wetlands holding water within 2, 3, or 5 km, I calculated past landscape level sandhill crane carrying capacities (1995-2019) using a combination of ranges of energetic requirement and seed content. Carrying capacity estimates were sufficient for all but 1 year (2010) and fell below the a priori threshold in 3 of the 4 energetic scenarios to provide forage for 135 days to all estimated 900,000 sandhill cranes. I applied climate and agricultural projections to these baseline models to estimate future carrying capacities for 3 decades in the 20th century (2025−2035, 2045−2055, and 2075−2085). Scenarios ranged in climate change severity from mild to severe and considered multidirectional effects from the input models. Results from 12 scenarios (4 each decade) suggest crane-energy-days (CED) would be below the minimum requirement estimate for 6 scenarios. Landscape suitability is under threat in the region due to rising temperatures and diminishing water resources, and wintering sandhill cranes will be forced to adapt to the changing landscape.

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