WINTER DISTRIBUTION OF SANDHILL CRANES FROM UPPER MICHIGAN AND ADJACENT ONTARIO—A THIRTY-YEAR PERSPECTIVE

The relationship between areas used for breeding and wintering by the expanding Eastern Population of greater sandhill cranes (Grus canadensis tabida) has been little studied. During 1985-1988, 32/33 (97%) of sandhill cranes VHFradiotagged on Seney National Wildlife Refuge (NWR) in the Upper Peninsula of Michigan were subsequently located on wintering areas in wet prairies, muck farms, and improved pastures in Florida and southern Georgia. Four additional radiotagged cranes from other areas of Upper Michigan and 7 from the North Channel of Lake Huron, Ontario, were also located in similar areas and habitats. Winter area was not dependent on summer location, but there was a tendency for cranes from the eastern portion of Seney NWR to winter near Blue Cypress Lake in south-central Florida. With few exceptions, individual cranes remained on their respective primary winter areas through January until late February when spring migration began. Fidelity to wintering areas from year to year was 85%. Winter distribution of cranes from Upper Michigan and adjacent Ontario was similar to the widespread but clumped distribution exhibited by the entire Great Lakes population. Comparable recent data (2010-2018) from other studies demonstrated expansion of winter distribution of Upper Michigan and Ontario cranes along the migration route from Indiana to Florida, similar to the Eastern Population of greater sandhill cranes in general. More limited wetland habitat north of Florida often resulted in larger flocks dependent on roost sites on public land rather than the more dispersed distribution in the historical winter areas in Florida. Although the Eastern Population of sandhill cranes has increased from 30,000 to possibly 90,000 or more individuals during the past 30 years, little recent research on wintering has occurred, especially within the changing landscape of Florida. Further documentation of crane numbers, areas used, and current roosting and feeding habitat is needed

BLACK FLY SURVEY OF A WHOOPING CRANE REINTRODUCTION AREA IN EASTERN WISCONSIN

Nest desertion due to harassment by black flies (Simulium annulus and S. johannseni) during incubation has been a major factor inhibiting success of the reintroduced Eastern Migratory Population of whooping cranes (Grus americana). To avoid this problem, which was prevalent in the core reintroduction area in central Wisconsin, the Whooping Crane Eastern Partnership changed the primary reintroduction area to eastern Wisconsin in 2011. However, a 2010 assessment of black flies in that area had concentrated predominantly on the southern portion of the new area. In 2017-2018, we collected the first samples of black flies in Green Lake County, including a new primary reintroduction site on White River Marsh (WRM), by sweep-netting over taxidermic crane mounts on artificial nests. In 2017, peak mean numbers of S. johannseni per sample at WRM and Grand River Marsh were 3,077 (maximum 6,838) and 891specimens, respectively. Numbers of black flies of this magnitude (and lower) collected during sampling by the same technique have been associated with nest desertion at Necedah National Wildlife Refuge in the core area. Numbers of S. johannseni were much lower in Green Lake County in 2018, and S. annulus was not abundant in either year. In contrast, an additional survey of black flies at WRM in 2021 recorded numbers of S. annulus potentially large enough to affect whooping crane nesting. Multi-year studies of black flies at WRM and other new reintroduction sites, coordinated with monitoring of whooping crane nesting, are needed to ascertain the impact of black flies and implement plans to promote success of this whooping crane population

Frontmatter for PROCEEDINGS OF THE FOURTEENTH NORTH AMERICAN CRANE WORKSHOP, 11-15 January 2017 Chattanooga, Tennessee

List of Previous Proceedings of the North American Crane Workshops: Suggested citation formats PREFACE Memorials: ROBERT H. HORWICH 1940-2017; WILLIAM A. LISHMAN 1939-2017; THEODORE A. BOOKHOUT 1931-2018; JAMES T. HARRIS 1950-2018 CONTENTS Front and back covers The North American Crane Working Group (NACWG) is an organization of professional biologists, aviculturists, land managers, non-professional crane enthusiasts, and others interested in and dedicated to the conservation of cranes and crane habitats in North America. Our group meets approximately every 3 years to exchange information pertaining to sandhill cranes and whooping cranes and occasionally reports about some of the other cranes species. The NACWG held the 14th North American Crane Workshop in Chattanooga, Tennessee, on 12-13 January 2017 preceded on 11 January by a social at the Chattanooga Zoo, and followed by field trips to nearby Hiwassee Wildlife Refuge on 14 January and to Wheeler National Wildlife Refuge (near Decatur, Alabama) on 15 January. The field trips coincided with the crane festivals held annually at both sites. Board member David Aborn did an outstanding job with local planning and arrangements. There were 70 registrants. The scientific program consisted of 37 oral and 14 poster presentations on North American cranes. Both field trip locations are major wintering areas for sandhill cranes and whooping cranes, and unusually warm weather resulted in great viewing. The L. H. Walkinshaw Crane Conservation Award, NACWG’s highest honor, was presented to Tom Stehn (Frontispiece). A special Award of Recognition was presented to local resident Ken Dubke, who was instrumental in Hiwassee Wildlife Refuge becoming a major sandhill crane migration stopover and wintering area and in raising historical awareness that led to creation of the Cherokee Removal Memorial. For many years Ken organized the annual Sandhill Crane and Cherokee Heritage Festival. During the NACWG business meeting, members voted to increase the size of the NACWG Board of Directors to 11 members, including a student representative; these currently include President Richard Urbanek, Vice-president Sammy King, Treasurer Barry Hartup, Secretary Daryl Henderson, David Aborn, Tommy Michot, Glenn Olsen, and new members George Archibald, Megan Brown, Paige Smith, and Hillary Thompson. The papers in these Proceedings represent 8 presentations from the workshop and 10 manuscripts submitted later. Abstracts of oral and poster presentations for which a paper is not published here are included at the end of the volume. Papers submitted for publication in the Proceedings are peer-reviewed according to scientific journal standards. We thank the following referees for their contribution to the quality of this volume: Ken F. Abraham, Jeb A. Barzen, David A. Brandt, Daniel P. Collins, Timothy A. Dellinger, Bruce D. Dugger, Taylor A. Finger, David L. Fronczak, Jeremy E. Guinn, Matthew A. Hayes, Jerome J. Howard, Gary L. Ivey, Eileen M. Kirsch, Susan N. Knowles, Anne E. Lacy, James R. Lovvorn, Robert G. McLean, Misty E. McPhee, Kim A. Miller, Neal D. Niemuth, Lovisa Nilsson, Gunter Nowald, Glenn H. Olsen, David Olson, Aaron T. Pearse, Brandon S. Reishus, Lisa A. Shender, Andrew P. Stetter, Thomas V. Stehn, Eva K. Szyszkoski, Josh L. Vest, Scott J. Werner, Brook J. Wilke, Jeffrey R. Wozniak, and Sara E. Zimorski. Daryl S. Henderson and Sara E. Zimorski were instrumental in final editing and proofing. This volume retains use of the genus Grus for 4 crane species (sarus, brolga, white-naped, and sandhill). Until analysis of nuclear DNA supports reclassification, the NACWG will continue to endorse the conclusions of Krajewski et al. (2010, Auk 127:440-452) and Krajewski (2018, Chapter 2 in Whooping Cranes: Biology and Conservation, Academic Press). Krajewski (personal communication, 2016) considers recent reclassification to the genus Antigone to be premature

PROCEEDINGS OF THE THIRTEENTH NORTH AMERICAN CRANE WORKSHOP--Abstracts

AGE-SPECIFIC SURVIVAL OF GREATER SANDHILL CRANE COLTS IN NEVADA. Chad August, Jim Sedinger, and Chris Nicolai 111 WHOOPING CRANE DISTRIBUTION AND HABITAT USE: PAST, PRESENT, AND FUTURE? Jane Austin, Matthew Hayes, and Jeb Barzen 111 BEHAVIORAL MOVEMENTS OF ARANSAS-WOOD BUFFALO WHOOPING CRANES: ANOMALIES OR INDICATIONS OF WAYS TO FURTHER ENHANCE SPECIES RECOVERY. David Baasch, Mark Bidwell, Wade Harrell, Kris Metzger, Aaron Pearse, and Mary Harner 112 INFLUENCES ON NEST SUCCESS IN A REINTRODUCED POPULATION OF WHOOPING CRANES. Jeb Barzen, Sarah Converse, Peter Adler, Elmer Gray, Anne Lacy, Eva Szyszkoski, and Andrew Gossens 113 DETERMINING DIET COMPOSITION AND INGESTION RATE OF CRANES THROUGH FIELD MEASUREMENT. Jeb Barzen, Ted Thousand, Julia Welch, Megan Fitzpatrick, Eloise Lachance, and Triet Tran 114 HABITAT USE AND MOVEMENT PATTERNS OF WHOOPING CRANES IN THE OIL SANDS MINING REGION. Mark Bidwell, David Baasch, Dave Brandt, John Conkin, Mary Harner, Wade Harrell, Kris Metzger, Aaron Pearse, and Richard Wiacek 115 CAPTURE AND DEPLOYING GPS PTTS ON ARANSAS-WOOD BUFFALO WHOOPING CRANES: LESSONS LEARNED WITH NEW TECHNIQUES AND TECHNOLOGIES. David Brandt, Aaron Pearse, Barry Hartup, Mark Bidwell, Felipe Chavez-Ramirez, and Bradley Strobel 116 CAN HORMONE METABOLITES PREDICT THE TIMING OF REPRODUCTIVE BEHAVIORS IN THE CAPTIVE WHOOPING CRANE?. Megan Brown, Sarah Converse, Jane Chandler, Carol Keefer, and Nucharin Songssasen 117 BREEDING DISTRIBUTION OF SANDHILL CRANES IN RUSSIA. Inga Bysykatova, Gary Krapu, and David Brandt 117 A REVIEW OF PARENT-REARING WHOOPING CRANES AT PATUXENT WILDLIFE RESEARCH CENTER, 1988-2003.Jane Chandler, Brian Clauss, and Glenn Olsen 118 PREDICTING OUTCOMES OF REINTRODUCTION STRATEGIES IN A DECISION-ANALYTIC SETTING.Sarah Converse, Sabrina Servanty, Patricia Heglund, and Michael Runge 118 MOVEMENT STRATEGIES OF SUBADULT INDIVIDUALS ON WINTER HABITAT INFLUENCE WINTER RANGE EXPANSION OF A MIGRATORY BIRD. Nicole Davis and Elizabeth Smith 119 PEOPLE OF A FEATHER FLOCK TOGETHER: A GLOBAL INITIATIVE TO ADDRESS CRANE AND POWER LINE INTERACTIONS.Megan Diamond, Jim Harris, Claire Mirande, and Jane Austin 120 EVALUATION OF LONGEVITY AND WEAR OF COLORED PLASTIC LEG-BANDS DEPLOYED ON SANDHILL CRANES IN WISCONSIN Katherine Dickerson and Matthew Hayes 120 SURVIVAL OF THE ROCKY MOUNTAIN SANDHILL CRANE. Roderick Drewien, William Kendall, Wendy Brown, and Brian Gerber 121 THE USE OF SATELLITE TELEMETRY TO EVALUATE MIGRATION CHRONOLOGY AND DISTRIBUTION OF EASTERN POPULATION SANDHILL CRANES. David Fronczak and David Andersen 121 NATIONAL WHOOPING CRANE ENVIRONMENTAL EDUCATION PROGRAM. Joan Garland and Erica Cochrane 122 THE ROLE OF POPULATIONS AND SUBSPECIES IN SANDHILL CRANE CONSERVATION AND MANAGEMENT. Brian Gerber and James Dwyer 122 ANNUAL VARIATION OF YOUNG OF THE YEAR IN THE ROCKY MOUNTAIN POPULATION OF SANDHILL CRANES.Brian Gerber, William Kendall, James Dubovsky, Roderick Drewien, and Mevin Hooten 123 AGE-SPECIFIC MIGRATORY AND FORAGING ECOLOGY OF EASTERN POPULATION GREATER SANDHILL CRANESEverett Hanna and Scott Petrie 124 EVALUATION OF A VACUUM TECHNIQUE TO ESTIMATE ABUNDANCE OF AGRICULTURAL GRAIN. Everett Hanna, Michael Schummer, and Scott Petrie 125 CHARACTERIZATION OF STOPOVER SITES USED BY WHOOPING CRANES AS DETERMINED FROM TELEMETRY-MARKED BIRDS. Mary Harner, Greg Wright, Aaron Pearse, David Baasch, Kris Metzger, Mark Bidwell, and Wade Harrell 126 MESHING NEW INFORMATION FROM THE WHOOPING CRANE TRACKING PARTNERSHIP WITH SPECIES RECOVERY GOALS—NEXT STEPS. Wade Harrell, Mark Bidwell, Aaron Pearse, Kris Metzger, Mary Harner, and David Baasch 127 HEALTH ASSESSMENT OF JUVENILE WHOOPING CRANES IN WOOD BUFFALO NATIONAL PARK. Barry Hartup 127 TERRITORY AVAILABILITY BEST EXPLAINS FIDELITY IN SANDHILL CRANES. Matthew Hayes and Jeb Barzen 128 MISSISSIPPI SANDHILL CRANE CONSERVATION UPDATE 2011-13. Scott Hereford and Angela Dedrickson 128 MIGRATION ROUTES AND WINTERING AREAS OF PACIFIC FLYWAY LESSER SANDHILL CRANES. Gary Ivey 129 A MODEL FOR MITIGATING LOSS OF CRANES FROM POWER LINE COLLISIONS. Gary Ivey 129 SPACE USE OF WINTERING WHOOPING CRANES Kris Metzger, Mary Harner, Greg Wright, Wade Harrell, Aaron Pearse, Mark Bidwell, and David Baasch 130 SOCIAL LEARNING OF MIGRATORY PERFORMANCE. . Thomas Mueller, Sarah Converse, Robert O’Hara, Richard Urbanek, and William Fagan 130 PARENT-REARING AND RELEASING WHOOPING CRANES IN WISCONSIN. Glenn Olsen and Sarah Converse 131 BEHAVIORAL COMPARISON OF COSTUME AND PARENT-REARED WHOOPING CRANE CHICKS. Glenn Olsen, Anne Harshbarger, Anna Jiang, and Sarah Converse 131 A TECHNIQUE FOR AGING CRANES Glenn Olsen and Scott Hereford 132 MIGRATION ECOLOGY OF ARANSAS-WOOD BUFFALO WHOOPING CRANES .Aaron Pearse, David Brandt, Mary Harner, Kris Metzger, Wade Harrell, Mark Bidwell, and David Baasch 132 THE SPATIAL AND TEMPORAL USE OF HABITATS BY A REINTRODUCED POPULATION OF WHOOPING CRANES IN LOUISIANATandi Perkins and Sammy King 133 BEHAVIOR ECOLOGY OF PEN-REARED, REINTRODUCED WHOOPING CRANES WITHIN THE LOUISIANA LANDSCAPETandi Perkins and Sammy King 133 CAPTURE OF SANDHILL CRANES USING ALPHA-CHLORALOSE. Lauren Schneider, Michael Engels, Matthew Hayes, Jeb Barzen, and Barry Hartup 134 A COMPREHENSIVE HABITAT TYPE DATASET FOR WHOOPING CRANE CONSERVATION PLANNING IN TEXAS, USA. Elizabeth Smith, Felipe Chavez-Ramirez, and Luz Lumb 135 EGG PRODUCTION BY FIRST-TIME BREEDERS IN THE EASTERN MIGRATORY POPULATION OF WHOOPING CRANES. Eva Szyszkoski 135 NATAL DISPERSAL OF WHOOPING CRANES IN THE REINTRODUCED EASTERN MIGRATORY POPULATION: THE FIRST TEN YEARS Hillary Thompson and Anne Lacy 136 CHANGES IN WINTER DISTRIBUTION OF THE REINTRODUCED EASTERN MIGRATORY WHOOPING CRANE POPULATION Richard Urbanek, Eva Szyszkoski, and Sara Zimorski 136 PAIR FORMATION IN THE REINTRODUCED EASTERN MIGRATORY WHOOPING CRANE POPULATION.Richard Urbanek, Eva Szyszkoski, Sara Zimorski, and Lara Fondow 137 A PRELIMINARY LOOK AT THE DEVELOPMENT AND TIMING OF CUES INFLUENCING PHILOPATRY IN CAPTIVE-BRED WHOOPING CRANES RELEASED USING THE MODIFIED DIRECT AUTUMN RELEASE METHODMarianne Wellington and Eva Szyszkoski 137 EGG FERTILITY RATE OF THE REINTRODUCED EASTERN MIGRATORY WHOOPING CRANE POPULATION 2005-2012. Amelia Whitear and Anne Lacy 138 REMOTE CAMERAS AID CRANE BEHAVIOR STUDIES: WET MEADOW UTILIZATION BY SANDHILL CRANES ALONG THE PLATTE RIVER, NEBRASKA.Greg Wright and Mary Harner 138 RECOVERY AND MANAGEMENT IN A FIELD ENVIRONMENT OF A JUVENILE WHOOPING CRANE FOLLOWING SURGERY TO REPAIR A FRACTURED LEFT CORACOID Sara Zimorski, James Lacour, Javier Nevarez, Katrin Saile, Jamie Wignall, João Brandão, Abbi Granger, and Patricia Queiroz-Williams 139 WHOOPING CRANES RETURN TO LOUISIANA: THE FIRST THREE YEARS. Sara Zimorski, Tandi Perkins, Vladimir Dinets, and Sammy King 14

NESTING OF GREATER SANDHILL CRANES ON SENEY NATIONAL WILDLIFE REFUGE

During 1987, 59 nests of 57 pairs of greater sandhill cranes (Grus canadensis tabida) were located, mainly from the air, on or near the Seney National Wildlife Refuge, Michigan, and 52 nests were ground-checked. Nests were in available palustrine classes without tree canopies. Only 19% were in Sphagnum bogs, in which most nests from other areas of the Upper Peninsula have been found. Cattail (Typha latifolia) marshes, most prevalent in the managed area of the refuge, contabed 44% of the nests, and sedge (Carex spp.) marshes accounted for 37%. Important co-dominant plant species were leatherleaf (Chamaedaphne calyculata), especially in bogs and sedge marshes, and willows (Salix ssp. Carex) in cattail and sedge marshes, sometimes forming shrub swamps. An estimated 33 of 52 clutches (63%) successfully hatched at least one chick. Thirteen clutches (25%) were believed destroyed by predators. Predation rate was least in sedge marshes, but differences in water depth, concealment, shrub cover, and distance from nearest upland were not statistically significant between sites of depredated and non-depredated nests. Nests of 30 pairs were found in an 11,600-ha intensively studied area in the eastern part of the refuge. An estimated 50 breeding pairs occur in this area, a density of 0.43 pairs/km2. The population has increased in recent history, and available nesting habitat is not a limiting factor to a larger nesting population

Local Scale Comparisons of Avian and Woody Vegetation Communities within Four Arkansas State Parks

Measuring the spatial distribution of biotic communities can provide useful data to wildlife managers on how and why species assemblages differ across a landscape. During 18 May – 7 August 2015, we conducted avian point counts and collected vegetation data in nested subplots at 4 Arkansas state parks. We then used a series of one-way ANOVAs and Kruskal-Wallis tests to examine differences in species richness, Simpson’s evenness, Simpson’s diversity, and Bray-Curtis similarity across the 4 parks. Mount Magazine State Park had the lowest avian evenness (F3,22 = 9.57 P = 0.003) and diversity (F3,22 = 17.8 P ≤ 0.001). Mount Magazine also had the lowest understory vegetation evenness (F3,22 = 9.41 P ≤ 0.001) and diversity (F3,22 = 17.8 P ≤ 0.001). Our analyses provided weak evidence supporting a possible relationship between avian and understory woody vegetation communities at Mount Magazine; however, this relationship was not observed in the remaining parks. Comparing biotic communities across 4 local state parks may aid park managers by providing a baseline of biotic data that can be used to better understand the collective effects acting on a specific park’s flora and fauna

Survival, Movements, Social Structure, and Reproductive Behavior During Development of a Population of Reintroduced, Migratory Whooping Cranes

An effort to reintroduce a migratory population of whooping cranes (Grus americana) into eastern North America began in 2001. During 2001-2004, 53 juveniles were released. All chicks were hatched at Patuxent Wildlife Research Center, Maryland, and transferred to Necedah National Wildlife Refuge (NWR), Wisconsin. Chicks were costume/isolation-reared and, with few exceptions, trained to follow ultralight aircraft, which led them to Chassahowitzka NWR, Central Gulf Coast of Florida. All individuals successfully returned to Central Wisconsin during their first spring migration except for the following: 5 individuals that were unable to navigate around Lake Michigan after taking an easterly migration route that terminated in Lower Michigan, and 1 female that did not return to Central Wisconsin until her second spring migration. A spring wandering period, in which yearlings typically explored and settled for several weeks in areas outside Central Wisconsin, followed spring migration. This temporary dispersal was more pronounced in females. Males summered in the core reintroduction area, while females not associated with males were more dispersed. In addition to the Michigan group noted, distant movements included 3 yearling females that summered in South Dakota, 1 female that summered as a yearling in Minnesota and then as a 2-year-old in Michigan, and 3 yearling males that staged in Minnesota in autumn. Many whooping cranes associated with sandhill cranes (G. canadensis). Many older whooping cranes returned to the Chassahowitzka pensite in subsequent fall migrations and then moved inland to winter in freshwater Florida habitats. The 2004-2005 winter was characterized by much greater dispersal than previous winters, with 14 of 34 returning birds wintering in South Carolina, North Carolina, or Tennessee. There were 12 mortalities during 2001-2005. These were associated with predation (7), gunshot (2), powerline strike (1), trauma of unknown source (1), and capture myopathy (1, euthanized). Mortalities due to predation resulted from bobcats (Lynx rufus) in southeastern U.S. (5), an undetermined predator in Wisconsin (1), and predation in Wisconsin of an adult that was roosting on land because of a fractured tarsus. A protective protocol was effective in reducing potential predation by bobcats at the Chassahowitzka release site after the first winter. During spring 2005, 7 breeding pairs were apparent on or near Necedah NWR. At least 5 of these pairs built nests, and 2 pairs each laid 1 egg. The young, inexperienced pairs did not adequately attend their nests, and neither egg survived. Four other potential pairs were also evident by summer 2005, and prospects were good for increased future reproductive activity

Intense myocyte formation from cardiac stem cells in human cardiac hypertrophy

It is generally believed that increase in adult contractile cardiac mass can be accomplished only by hypertrophy of existing myocytes. Documentation of myocardial regeneration in acute stress has challenged this dogma and led to the proposition that myocyte renewal is fundamental to cardiac homeostasis. Here we report that in human aortic stenosis, increased cardiac mass results from a combination of myocyte hypertrophy and hyperplasia. Intense new myocyte formation results from the differentiation of stem-like cells committed to the myocyte lineage. These cells express stem cell markers and telomerase. Their number increased >13-fold in aortic stenosis. The finding of cell clusters with stem cells making the transition to cardiogenic and myocyte precursors, as well as very primitive myocytes that turn into terminally differentiated myocytes, provides a link between cardiac stem cells and myocyte differentiation. Growth and differentiation of these primitive cells was markedly enhanced in hypertrophy, consistent with activation of a restricted number of stem cells that, through symmetrical cell division, generate asynchronously differentiating progeny. These clusters strongly support the existence of cardiac stem cells that amplify and commit to the myocyte lineage in response to increased workload. Their presence is consistent with the notion that myocyte hyperplasia significantly contributes to cardiac hypertrophy and accounts for the subpopulation of cycling myocytes

Conserved biological function between Pax-2 and Pax-5 in midbrain and cerebellum development: Evidence from targeted mutations

The development of two major subdivisions of the vertebrate nervous system, the midbrain and the cerebellum, is controlled by signals emanating from a constriction in the neural primordium called the midbrain/hindbrain organizer (Joyner, A. L. (1996) Trends Genet. 12, 15–201). The closely related transcription factors Pax-2 and Pax-5 exhibit an overlapping expression pattern very early in the developing midbrain/hindbrain junction. Experiments carried out in fish (Krauss, S., Maden, M., Holder, N. & Wilson, S. W. (1992) Nature (London) 360, 87–89) with neutralizing antibodies against Pax-b, the orthologue of Pax-2 in mouse, placed this gene family in an regulatory cascade necessary for the development of the midbrain and the cerebellum. The targeted mutation of Pax-5 has been reported to have only slight effects in the development of structures derived from the isthmic constriction, whereas the Pax-2 null mutant mice show a background-dependent phenotype with varying penetrance. To test a possible redundant function between Pax-2 and Pax-5 we analyzed the brain phenotypes of mice expressing different dosages of both genes. Our results demonstrate a conserved biological function of both proteins in midbrain/hindbrain regionalization. Additionally, we show that one allele of Pax-2, but not Pax-5, is necessary and sufficient for midbrain and cerebellum development in C57BL/6 mice