Comparative wintering ecology of two subspecies of sandhill crane : informing conservation planning in the Sacramento-San Joaquin River Delta region of California

California's Central Valley agricultural landscapes provide several important wintering regions for Pacific Flyway sandhill crane (Grus canadensis) populations; however, the value of those regions is being compromised by urban expansion, other developments, and conversions to incompatible crop types. Greater (G. c. tabida) and lesser sandhill cranes (G. c. canadensis) both have special conservation status in California; the greater is listed as threatened and the lesser as a bird species of conservation concern by the state. However, basic information about their wintering ecology has been lacking to design biologically sound conservation strategies to maintain their wintering habitats. My study of sandhill cranes focused on one major Central Valley wintering region, the Sacramento-San Joaquin River Delta (Delta). I compared daily movements and winter site fidelity between the two sandhill crane subspecies, evaluated the timing of crane arrival and departure from the region, assessed foraging habitat choices, measured abundance and distribution in the Delta, documented the characteristics of roost sites, and developed habitat conservation models and decision tools for managers to facilitate habitat conservation and management. Both crane subspecies showed strong fidelity to my Delta study area. Foraging flights from roost sites were shorter for greaters than lesser (1.2 ± 0.4 km vs. 3.1 ± 0.1 km, respectively) and consequently, mean size of 95% fixed kernel winter home ranges was an order of magnitude smaller for greaters (1.9 ± 0.4 km² vs.21.9 ± 1.9 km², respectively). The strong site fidelity of greaters to roost complexes within landscapes in the Delta indicates that conservation planning targeted at maintaining and managing for adequate food resources around traditional roost sites can be effective for meeting sandhill crane habitat needs, while the scale of conservation differs by subspecies. I recommend that conservation planning actions consider all habitats within 5 km of a crane roost as a sandhill crane conservation "ecosystem unit." This radius encompasses 95% and 69% of the flights from roosts to foraging location (commuting flights) made by greaters and lessers, respectively. For lessers, a conservation radius of 10 km would encompass 90% of the commuting flights. Management, mitigation, acquisition, easement, planning, and farm subsidy programs intended to benefit cranes will be most effective when applied at these scales. Within these radii, conservation and management of wintering habitats should include creating both new roost and feeding areas to ensure high chances of successful use. Sandhill cranes used major crops and habitat types available in the landscapes surrounding their roost sites and focused most of their foraging in grain crops. They generally avoided dry corn stubble, selected dry rice stubble early in the season, and rarely used dry wild rice stubble. Tilled fields were also usually avoided but were occasionally used shortly after tillage. Mulched corn ranked high in comparison to other corn treatments while mulched rice use was used similarly to dry rice stubble. Both subspecies often highly favored cropland habitats when they were initially flooded. Cranes were attracted to new plantings of pasture and winter wheat. One important difference between the subspecies was that lessers used alfalfa which was generally avoided by greaters. Dry corn stubble was avoided while dry rice stubble was favored early in winter. If wildlife managers want to encourage winter field use by cranes they could provide incentives for favorable practices such as production of grain crops, reduction or delaying tillage and flooding of grain fields, provision of irrigations to some crop types, and increasing the practice of mulching of corn stubble. Of the 69 crane night roosts I identified, 35 were flooded cropland sites and 34 were wetland sites. I found that both larger individual roost sites and larger complexes of roost sites supported larger peak numbers of cranes. Water depth used by roosting cranes averaged 10 cm (range 3-21 cm, mode 7 cm) and was similar between subspecies. Roosting cranes avoided sites that were regularly hunted or had high densities (i.e., > 1 blind/5 ha) of hunting blinds. Roost site design and management should consider providing and maintaining large roost complexes (100 - 1000 ha) ideally in close proximity ( 5 ha) of mostly level topography, dominated by shallow water (5-10 cm depths). The fact that cranes readily use undisturbed flooded cropland sites makes this a viable option for creation of roost habitat. Because hunting disturbance can limit crane use of roost sites I suggest these two uses should not be considered compatible. However, if the management objective of an area includes waterfowl hunting, limiting hunting at low blind densities (i.e., < 1 blind/60 ha) and restricting hunting to early morning may be viable options for creating a crane-compatible waterfowl hunt program. Radio-marked sandhill cranes arrived in the Delta beginning 3 October, most arrived in mid-October, and the last radio-marked sandhill crane arrived on 10 December. Departure dates ranged from 15 January to 13 March. Mean arrival and departure dates were similar between subspecies. From mid-December through early-February in 2007-2008, the Delta population ranged from 20,000 to 27,000 sandhill cranes. Abundance varied at the main roost sites during winter, likely because sandhill cranes responded to changes in water and foraging habitat conditions. Sandhill cranes used an area of approximately 1,500 km² for foraging. Estimated peak abundance in the Delta was more than half the total number counted on recent Pacific Flyway midwinter surveys, indicating the Delta region is a key area for efforts in conservation and recovery of wintering sandhill cranes in California. Based on arrival dates, flooding of sandhill crane roost sites should be staggered with some sites flooded in early September and most sites flooded by early October. Maintaining flooding of at least some roost sites through mid-March would provide essential roosting habitat until most birds have departed the Delta region on spring migration. Not all 5-km radius ecosystem units are equal in their value to greater sandhill cranes, and the relative foraging value of a particular parcel within an ecosystem unit depends on the numbers of cranes using the focal roost site, the habitat choices they make, and the probability that they will fly to a particular parcel. Additionally, some ecosystem units overlap, and in these overlap zones, the probability of crane use is higher, because of additive effects. To provide a tool to allow managers to further refine management plans, I developed a model which allows more specific focus of crane conservation, mitigation and habitat management, using what my study revealed about greater sandhill cranes. This model considers the abundance of greaters at individual roost sites and the probability that they would fly to a given location. Sites closer to roosts had a higher probability of crane use. I calculated the probability that greaters would fly to a parcel within concentric 1-km intervals as a product of the proportion of commuting flights of individuals that reached that interval, and the proportion of all commuting flights that reached that interval. Within crane ecosystem units, it is important to protect the existing habitat from further loss and optimize foraging conditions for cranes. I provide a decision matrix to assist with plans to enhance existing crane landscapes, create new crane habitat areas or mitigate habitat losses. This matrix provides a framework for decision-making regarding enhancing sandhill crane foraging and roost site habitats. Wildlife managers could employ a variety of tools to conserve and manage crane habitats, including fee title acquisitions, private conservation easements, and specific cropland management actions to maintain crane-compatible conditions and high food values for cranes (possibly including providing unharvested food plots). My study has demonstrated that most cranes use a relatively small landscape surrounding their traditional roost sites and that they favor certain crops and post-harvest crop management practices for foraging. However, we need a better understanding of the actual carrying capacity for cranes in these crane management zones to ensure that managers can maintain these sites for cranes in the future

Factors influencing nest success of greater sandhill cranes at Malheur National Wildlife Refuge, Oregon

I developed a priori hypotheses and used logistic regression to model Greater Sandhill Crane (Grus canadensis tabida) nest success in relation to weather, habitat and management variables for cranes breeding at Malheur National Wildlife Refuge (MNWR) in southeast Oregon. My primary interest was to investigate the effects of habitat conditions and management practices on nest success as these factors can be influenced by managers. However, I also included variables for weather, water supply, and nest initiation date to provide a context for understanding the relative importance of management actions and habitat conditions. I monitored 506 nests over 9 breeding seasons; mean apparent nest success was 72% ± 4% and varied from 51 to 87%. Nest success varied by habitat management within a field, nest-season temperatures, and water at the nest site. A second analysis which included a subset of nests with nest initiation data revealed that nest success declined with initiation and was higher during years of moderate recipitation. Variable importance analysis indicated initiation date had a greater influence on nest success (0.99) than land use (0.74), water depth (0.50), water supply (0.42), or temperature (0.30). Grazing, haying and predator control had no effect on nest success, while burning had a negative effect, but only during the nesting season following the burn. The lack of a predator control effect may have been due to elimination of individual problem animals before the study commenced, and a protracted effect of the control program. It may also be due to the relatively smaller importance of predator control at higher nest success rates. Nest success at MNWR was higher during my study than in most studies and the low proportion of failed nests may have reduced my ability to detect influences of some variables such as land use practices and predator control. My study is the first to quantify the effect of temperature and moisture conditions on nest success and the results suggest adequate water availability is important for nesting cranes. It affirms the importance of water depth, but not concealment, indicating that the height of cover surrounding a nest is not very important. During the 8-year coyote (Canis latrans) and Common Raven (Corvus corax) control program at MNWR non-target predator populations increased. Such control programs can have unforeseen consequences, such as release of mesopredator populations which can cause additional crane productivity problems. Nest success was relatively high during my study yet productivity was very low, averaging around 3.3 young per 100 pairs from 1995-1998 (GLI, unpublished data). Efforts to further increase nest success at MNWR using predator control are not warranted. The effect of predators on chick survival is likely of more importance and should be quantified to aid in the interpretation of predator control as a management tool. Managers should focus on providing early water to crane territories to facilitate earlier nesting and water levels should be maintained through the nesting season to limit abandonment. Haying and grazing of meadows will likely encourage cranes to nest in deeper water marsh sites. Although burning showed negative effects on nest success during the first season following burns, I advocate continued, but careful use of this important habitat management tool. Lastly, in addition to management to improve nest success, managers should consider efforts to enhance chick and adult survival, as these factors are likely more important than nest success in maintaining populations

HISTORIC AND RECENT WINTER SANDHILL CRANE DISTRIBUTION IN CALIFORNIA

Understanding the geographic distribution and long-term dynamics of winter foraging areas and night roost sites of sandhill cranes (Grus canadensis) is important to their conservation and management. We studied sandhill crane distribution in California’s Central Valley from December 2012 through February 2013. We mapped observed flock and night roost locations. Flock locations occurred between Tehama County in the north and Kern County in the south. Flocks were concentrated in the northern Sacramento Valley, the Sacramento-San Joaquin Delta, the northern San Joaquin Valley south of Tracy to Mendota (including the lower Stanislaus and Tuolumne River floodplains and the Grasslands Region), and the southern San Joaquin Valley in the vicinity of Pixley in Tulare County. We also reviewed records of historic occurrences of cranes in California to interpret the importance of our flock and night roost locations. Although cranes wintered in the Los Angeles, San Diego, and San Francisco Bay metropolitan areas in the 19th and early 20th centuries, they no longer occur in significant numbers in these areas due to widespread habitat loss. Three additional areas which were used in the mid-20th century have apparently been abandoned or are being used only infrequently: the Red Bluff area (along the Sacramento River between Red Bluff and Anderson, Tehama County), the Goose Lake area (Kern County), and the Carrizo Plain (San Luis Obispo County). The primary cause of site abandonment at these sites is loss of suitable foraging habitat (small grain crops). With the exception of the Southern San Joaquin region, crane winter range has expanded in the Central Valley since the 1960s. Range expansion has principally been due to expansion of public wildlife refuges and private sanctuaries, plus improvements in their management (including reductions in hunting disturbance). To improve habitat conditions for cranes across their Central Valley wintering range, we recommend that management be focused on protection, enhancement, and creation of crane habitat complexes, each of which should contain 1 or more roost sites surrounded by sufficient well-managed foraging habitat. The following conservation strategies (listed in order of priority) should be implemented for each major crane wintering region: 1) protect existing, unprotected roost sites by fee-title acquisition or conservation easements (prioritize among sites according to their importance to greater sandhill cranes; G. c. tabida); 2) protect foraging landscapes around existing roosts, primarily through easements restricting development and crop types that are incompatible to cranes; 3) enhance food availability within those landscapes by improving foraging conditions on conservation lands and providing annual incentives for improvements on private lands; and 4) create additional protected roost sites toward the edge of their existing range where birds can access additional foraging areas

CHARACTERISTICS OF SANDHILL CRANE ROOSTS IN THE SACRAMENTO-SAN JOAQUIN DELTA OF CALIFORNIA

The Sacramento-San Joaquin Delta (Delta) region of California is an important wintering region for 2 subspecies of Pacific Flyway sandhill cranes (Grus canadensis): the Central Valley Population of the greater sandhill crane (G. c. tabida) and the Pacific Flyway Population of the lesser sandhill crane (G. c. canadensis). During the winters of 2007-08 and 2008-09 we conducted roost counts, roadside surveys, aerial surveys, and tracked radio-marked birds to locate and assess important habitats for roosting cranes in the Delta. Of the 69 crane night roosts we identified, 35 were flooded cropland sites and 34 were wetland sites. We found that both larger individual roost sites and larger complexes of roost sites supported larger peak numbers of cranes. Water depth used by roosting cranes averaged 10 cm (range 3-21 cm, mode 7 cm) and was similar between subspecies. We found that cranes avoided sites that were regularly hunted or had high densities of hunting blinds. We suggest that managers could decide on the size of roost sites to provide for a given crane population objective using a ratio of 1.5 cranes/ha. The fact that cranes readily use undisturbed flooded cropland sites makes this a viable option for creation of roost habitat. Because hunting disturbance can limit crane use of roost sites we suggest these 2 uses should not be considered readily compatible. However, if the management objective of an area includes waterfowl hunting, limiting hunting to low blind densities and restricting hunting to early morning may be viable options for creating a crane-compatible waterfowl hunt program

Achieving Teaching, Scholarship, and Service through Community Engagement

Occupational therapy faculty currently face enormous challenges in meeting teaching load expectations, while also under pressure to participate in scholarly projects and to make administrative and service contributions. Community engagement projects may provide opportunities for faculty to effectively and efficiently meet the goals in each of these areas while imparting benefits to students and community partners as well. Faculty at the Department of Occupational Therapy (OT) at Virginia Commonwealth University (VCU) embraced this idea as consistent with the university’s mission and strategic plan, and recognized its benefits in assisting faculty to meet workload demands. Four community partnerships reflecting the range and diversity of populations currently involved are highlighted: the Children’s Museum of Richmond, Rebuilding Together-Richmond, the William Nelson Bland Literacy Center, and Gateway Homes of Richmond. The developmental process and resulting benefits are described for each of these partnerships, and the paper concludes with lessons learned from these collaborative efforts. From these examples, it appears important to be proactive about developing community partnerships and realistic about the challenges of collaboration, but also to be aware of the role community engagement plays in creatively blending the potentially conflicting demands on faculty time

Wintering ecology of sympatric subspecies of Sandhill Crane: Correlations between body size, site fidelity, and movement patterns

Body size is known to correlate with many aspects of life history in birds, and this knowledge can be used to manage and conserve bird species. However, few studies have compared the wintering ecology of sympatric subspecies that vary significantly in body size. We used radiotelemetry to examine the relationship between body size and site fidelity, movements, and home range in 2 subspecies of Sandhill Crane (Grus canadensis) wintering in the Sacramento–San Joaquin Delta of California, USA. Both subspecies showed high interannual return rates to the Delta study area, but Greater Sandhill Cranes (G. c. tabida) showed stronger within-winter fidelity to landscapes in our study region and to roost complexes within landscapes than did Lesser Sandhill Cranes (G. c. canadensis). Foraging flights from roost sites were shorter for G. c. tabida than for G. c. canadensis (1.9 ± 0.01 km vs. 4.5 ± 0.01 km, respectively) and, consequently, the mean size of 95% fixed-kernel winter home ranges was an order of magnitude smaller for G. c. tabida than for G. c. canadensis (1.9 ± 0.4 km² vs. 21.9 ± 1.9 km², respectively). Strong site fidelity indicates that conservation planning to manage for adequate food resources around traditional roost sites can be effective for meeting the habitat needs of these cranes, but the scale of conservation efforts should differ by subspecies. Analysis of movement patterns suggests that conservation planners and managers should consider all habitats within 5 km of a known G. c. tabida roost and within 10 km of a G. c. canadensis roost when planning for habitat management, mitigation, acquisition, and easements.Keywords: Sandhill Crane, home range, Grus canadensis, scale, California, site fidelity, conservation planning, wintering ecology, Sacramento-San Joaquin Delt

RESULTS OF EIGHT YEARS OF PREDATOR CONTROL TO ENHANCE SANDHILL CRANE PRODUCTION ON MALHEUR NATIONAL WILDLIFE REFUGE, OREGON

Because of a 21 % decline in breeding pairs of greater sandhill cranes (Grus canadensis tabida) on Malheur National Wildlife Refuge from 1971 to 1985, a predator control program was initiated in 1986 to enhance production. The primary cause for the decline was low recruitment of young due to high predation by ravens (Corvus corax). raccoons (Procyon lotor), and coyotes (Canis latrans), On average, predators destroyed 46% of all crane nests and 90% of the prefledged colts. Mink (Mustela vison) were added to the program in 1993 after a study showed them to be an important predator of colts. During the 8 years of the predator control program, crane nest success averaged 68%, compared to 47% before the control program. Predators destroyed an average of21.5% of crane nests during the control program, compared to 46% during years when no predator control was practiced. Average colt survival was 15.1 % during the predator control years vs, 9.8 % during years without predator control, and average productivity was 15.9 young per 100 pairs vs. 11.0. The best validation of success of the program was the recovery of the breeding population, which increased from 168 breeding pairs in 1989 to 238 in 1994

MORTALITY OF RADIO-EQUIPPED SANDHILL CRANE COLTS AT MALHEUR NATIONAL WILDLIFE REFUGE, OREGON

We radio-equipped 142 greater sandhill crane (Grus canadensis tabida) colts at Malheur National Wildlife Refuge, Oregon, during 1991-95 to document prefledging mortality factors. Fates of 19 colts were undetermined. A total of 23 colts survived to fledge (19% of known fates). Evidence collected from the carcasses and death sites indicated that predators were responsible for the largest number of colt deaths (64), followed by unknown causes (13), parasitic gapeworms (Cyastoma spp.) (8), drowning (7), intraspecific aggression (5), study-related mortality (I), roadkill (I), and hay swather (1). Of 64 colts killed by predators, 26 were lost to mink (Mustela vison), 10 to great horned owls (Bubo virginianus), 9 to golden eagles (Aquila chrysaetos), 7 to unidentified predators, 5 to coyotes (Canis latrans), 5 to unidentified raptors, 1 to a northern harrier (Circus cyaneus), and 1 to a raccoon (Procyon lotor). Because mink were the most significant predator, we initiated an experimental mink control program in 1993. Losses from mink in 1993 were reduced to 9%, compared with 36% and 27% in 1991 and 1992, respectively. We concluded that an integrated approach involving habitat management and predator and parasite control could be used to enhance crane productivity

Sandhill Crane Wintering Ecology in the Sacramento-San Joaquin Delta, California

We studied wintering sandhill crane (Grus canadensis) ecology in 2002–2003 in the Sacramento-San Joaquin Delta of California, focusing on Staten Island, a corporate farm which was acquired by The Nature Conservancy and managed to promote sustainable agriculture that is beneficial to wildlife. Our purpose was to define habitat conservation needs for cranes, including the state-threatened greater subspecies (G. c. tabida). Research was conducted through intensive surveys by vehicle of crane foraging and roosting behavior. We estimated that about 1,500 greaters used Staten Island, which is a significant portion of the Central Valley Population of greater sandhill cranes and Staten Island supported 36% of all crane foraging use in the Delta region through the entire winter. Use of crops shifted in response to availability, with cranes showing highest preference for wheat. Corn, however, was the most important crop through the entire winter. Our estimates of winter home ranges of color-marked greaters averaged 1.7 km2 ± 0.52 SD (n = 39) while flight distances from roost sites to foraging areas averaged 1.4 km. In contrast, marked lesser sandhill cranes (G. c. canadensis) indicated much larger winter ranges (mean 18.6 km2 ± 5.32 SD; n = 39) and foraged much further from roost sites. Another relevant finding in our study was strong site fidelity of greaters. Some color-marked greater sandhill cranes are known to have used the same local wintering areas for at least 18 years, highlighting the importance of maintaining these traditional use areas. Other results demonstrate that crane welfare could be enhanced by provision of crane-compatible crops and roost sites in close proximity, implementing crane-friendly agricultural practices, and minimizing disturbance

Factors influencing greater sandhill crane nest success at Malheur National Wildlife Refuge, Oregon

We used logistic regression to model the effects of weather, habitat, and management variables on Greater Sandhill Crane (Grus canadensis tabida) nest success at Malheur National Wildlife Refuge in southeast Oregon. We monitored 506 nests over 9 breeding seasons. Mean apparent nest success was 72% ± 4% and varied from 51 to 87%. Nest success was lower one year after a field was burned and declined with nest initiation date. Nest success was higher during warmer springs, in deeper water, and in years with moderate precipitation. Haying, livestock grazing, and predator control did not influence nest success. We suggest the short-term consequence of burning on nest success is outweighed by its long term importance and that water level management is the most important tool for managing crane nest success. Finally, studies of brood ecology are needed to develop a more complete picture of crane nesting ecology