The Wisconsin Society for Ornithology (WSO) was organized in 1939 to encourage the study of Wisconsin birds. The goals of the Society have since expanded to emphasize all of the many enjoyable aspects of birding, and to support the research and habitat protection necessary to preserve Wisconsin birdlife. WSO strives to alert members and the public to situations and practices that threaten Wisconsin’s bird populations. WSO provides the following information in the interest of educating its members as well as the general public regarding the possibility of a Sandhill Crane hunting season in Wisconsin. The Society recognizes that a major partner in our mission is the hunting community of Wisconsin – in fact, many of our members are hunters. The sales of hunting and fishing licenses, stamps, permits, and other hunting-related taxes have provided an essential funding source for wildlife conservation projects. While WSO acknowledges and supports the cultural heritage of hunting in our state, it recognizes that the harvest of some wildlife species may be biologically or socially unacceptable.
SANDHILL CRANE ECOLOGY
Sandhill Cranes are distributed throughout North America, extending into Cuba and northeastern Siberia. Three subspecies migrate throughout North America: the Lesser (Grus canadensis canadensis), Greater (G. c. tabida), and Canadian (G. c. rowani) Sandhill Crane. All of Wisconsin’s Sandhill Cranes belong to the Greater subspecies. There is debate on whether there are one, two, or three migratory subspecies. The Greater and Canadian subspecies are lumped by some (Rhymer et al. 2001), and others suggest that there is only one migratory population (Jones et al. 2005).
The U.S. Fish and Wildlife Service (USFWS) recognizes six migratory populations of Sandhill Cranes for management purposes based on geography rather than subspecies: Pacific Flyway (Lesser), Central Valley (Greater), Lower Colorado River Valley (Greater), Rocky Mountain (Greater), Eastern (Greater) and Mid-Continent (Lesser, Greater and Canadian) (Van Horn et al. 2011). The Eastern Population of the Greater Sandhill Crane is distinct, having no overlap with other populations. The total Eastern Population of the Greater Sandhill Crane, including all of the Sandhill Cranes in Wisconsin, is estimated to be between 60,000 and 70,000 individuals (Kruse et al. 2012). The Mid-Continent Population is the most abundant of the six regional populations with a population estimate between 500,000 and 600,000 individuals (Kruse et al. 2012).
Historically, the Greater Sandhill Crane bred in suitable wetland sites throughout North America (Tacha et al. 1992). However, hunting along with habitat changes in the eighteenth and nineteenth centuries led to the extirpation of the Greater Sandhill Crane from many parts of its breeding range. The Sandhill Crane disappeared as a breeding bird from Illinois (1890), Iowa (1905), South Dakota (1910), Ohio (1926), and Indiana (1929), and was nearly extirpated from several other states. In Wisconsin, the Sandhill Crane was reduced to an estimated 25 breeding pairs in the 1930s (Henika 1936, Meine and Archibald 1996). Since that time, hunting bans and habitat protection efforts have helped Sandhill Crane populations to slowly recover.
Beginning in 1961, hunting of the Sandhill Crane began under modern hunting regulations. A total of 15 states now have hunting seasons for Sandhill Cranes. The majority of states with Sandhill Crane hunting seasons harvest from the most abundant regional population – the Mid-Continent Population. The remaining states, Arizona, Idaho, Utah, Montana, New Mexico, and Wyoming, harvest from the Rocky Mountain Population. In 2011, Kentucky became the first state and the Fond du Lac tribe of Minnesota became the first tribe to allow hunting from the Eastern Population of Greater Sandhill Cranes (Kruse et al. 2012). In 2012, the tribal hunting territory of northern Wisconsin was open for the hunting of Sandhill Cranes by tribal members only.
INFORMATION TO CONSIDER
Sandhill Cranes have the longest life span, highest adult survival, but lowest percentage of juveniles within the total population of any game bird in North America (Drewien et al. 1995). This is important because the number of juveniles present in a population provides insight into the population’s ability to support harvest (Drewien et al. 1995). There are several factors that contribute to the low ratio of juveniles to adults. Unlike most game birds, which begin breeding at one year of age, Sandhill Cranes are slow to mature (Tacha et al. 1992, Van Horn et al. 2011). The average age for the first successful breeding of Greater Sandhill Cranes is four years (Tacha et al. 1992, Hayes and Barzen 2006). Some pairs take as long as eight years to produce young that survive to independence. Additionally, Sandhill Crane pairs produce fewer young annually compared to other game birds. Sandhill Cranes rarely raise more than one chick (called colts in cranes) each year (Tacha et al. 1992, Van Horn et al. 2011), and many of these chicks do not survive their first year of life. A 22-year study of Sandhill Cranes in central Wisconsin revealed that, on average, only 0.44 chicks survive to fall migration per territory per year. Chick survival has been consistently declining throughout this period so that, in 2012, that number was reduced to one chick per ten nests (Barzen, pers. com.). This low chick survival has occurred with no apparent connection to known variables such as climate.
Given that Sandhill Cranes produce smaller clutches and have delayed maturity, they need long periods of time to recover from population declines. It is therefore imperative to have a reliable means to measure population abundance. Without this information, the potential for overharvest is high. Although population estimates for Eastern Population Sandhill Cranes are currently derived from several standardized surveys, it is not clear whether these surveys provide the precision needed to prevent overharvest. Evaluation of fall surveys is complicated by changes in observer effort over the years, making trend analysis difficult (Barzen, pers. com.).
Potential Confusion with Whooping Cranes
Wisconsin now has a population of Whooping Cranes (Grus americana). Technically this species has endangered status, although the birds that are part of the Wisconsin flock have a somewhat different legal status (“experimental, non-essential”). Twenty-five percent of the world’s wild Whooping Cranes now summer in Wisconsin. Many conservationists are concerned that Whooping Cranes could be accidentally mistaken for Sandhill Cranes during a legal hunt. In poor light or bad weather conditions, the silhouette of a Whooping Crane is nearly identical to that of a Sandhill Crane. Although no legally hunting Sandhill Crane hunter has ever shot a Whooping Crane, there has been one case of Whooping Crane mortality associated with a Sandhill Crane hunt. In this incident, Sandhill Crane hunters killed three Whooping Cranes while hunting illegally before shooting hours and thus in poor light conditions. In an attempt to address this issue, the USFWS has prepared materials to educate hunters on the differences between Whooping and Sandhill Crane identification (USFWS 2012). Additionally, state wildlife agencies that have hunting seasons often require Sandhill Crane hunters to complete an education course, which includes Whooping Crane identification.
Further complicating this issue, Whooping Cranes frequently associate with Sandhill Cranes. Whooping Crane Eastern Partnership personnel have facilitated the mixing of the two species as part of the Direct Autumn Release reintroduction technique. This method involves releasing young-of-the-year Whooping Cranes into wetlands frequented by Sandhill Cranes. Young Whooping Cranes have some brown plumage in late summer and early fall, gradually acquiring adult plumage through the winter months. Thus, during a fall harvest, a young Whooping Crane associating with a Sandhill Crane flock could be mistaken for a Sandhill Crane. Even adult Whooping Cranes and Sandhill Cranes can be difficult to distinguish under bright light conditions in autumn after Sandhills have undergone their molt.
Agricultural Damage Caused by Cranes
Sandhill Cranes can cause considerable agricultural damage, primarily to field corn and potatoes, which has generated some negative sentiments from the agricultural community. In Wisconsin, depredation by cranes occurs primarily on seedling corn, and to a lesser extent on potatoes. Currently, shooting of Sandhill Cranes is granted to farmers with demonstrated crop damage via agricultural damage shooting permits. These permits are typically issued in the spring and early summer, when crop damage is most likely. Although some proponents of a Sandhill Crane hunt have suggested that a fall harvest might provide a partial solution to the crop damage issue, Wisconsin Department of Natural Resources (WDNR) and International Crane Foundation (ICF) have determined that even a carefully regulated autumn hunt would not be an effective deterrent to cranes causing spring crop damage.
Researchers from ICF have been investigating non-lethal methods to reduce agricultural damage by Sandhill Cranes. They determined that common methods of deterrence, such as propane cannons that create loud noises and other similar responses, are often not effective at controlling or preventing crop damage by cranes (ICF 2012). One method that shows great promise is a chemical repellant known as Avipel®. Avipel® contains the compound 9,10 anthraquinone (AQ), a naturally produced biochemical found in some plants. Corn seeds treated with this compound are unpalatable to cranes. Avipel® has the additional benefits of low toxicity and relatively low environmental impact. Beginning in March 2006, the Environmental Protection Agency permitted the application of AQ on corn seeds planted in Michigan, Minnesota, and Wisconsin. ICF continues to monitor the effectiveness of this method (ICF 2012).
Not all animal species need to be managed with a goal of having a sufficient population so that they can be hunted. Aldo Leopold was a hunter for much of his life. He also wrote the first widely used textbook on Wildlife Management, and held the world’s first academic chair in wildlife management at the University of Wisconsin, teaching that subject and ecology for many years. He famously attempted to get people to see that the land could be coaxed to not only “say beans”, (produce agricultural crops) but to “say quail”, or deer, (produce wildlife) as well. But Leopold went far beyond simply teaching land and wildlife management. Although he valued conservation for the practical benefits that accrued from practicing it, he went far deeper. He developed a philosophical position, an ethic: the “land ethic.” He was not content to say that we can practice conservation so that we could simply use things more efficiently, or keep them around long enough for our children to benefit from them – although all of those things are true. He realized that our relationship to the natural world – to the land – is much, much more. It underpins how we live our lives at a deeper level, beyond the strictly utilitarian concerns of natural resources policy, or wildlife management. Leopold intuited that ethics compels people to work together so that all in the community could benefit. One of his main points was that the community was not composed of humans only, but that it included other elements such soils, waters, plants, and animals; or collectively: the land. One of his most famous quotes reads: “That land is a community is the basic concept of ecology, but that land is to be loved and respected is an extension of ethics”(Leopold 1949).
Perhaps we can take Leopold’s implicit guidance and learn to see some species truly as fellow members of the community that we love and respect. The Sandhill Crane is a symbol, one that reminds us of Leopold, one that reminds us of his teachings, and one that we can hold onto and protect. That may be enough.
This relates to a more complex view of the ethics of hunting. The hunting of Sandhill Cranes in Wisconsin may be biologically defensible but may not be from a cultural, societal, philosophical, or spiritual standpoint. Many persons value cranes and other wild species in ways that are not encompassed by a philosophically “instrumental” explanation. Many see wild creatures not merely as sources of food, but as members of a complex, biodiverse natural world, and which provide intellectual, emotional, and spiritual enrichment. These viewpoints are equally valid, and represent the views of many citizens, although they may not be examples of the views of all people who do not choose hunting. Some support legal and managed hunting of widespread and abundant game species but not necessarily hunting for this species.
A Sandhill Crane hunt is being proposed for the state of Wisconsin. All of Wisconsin’s Sandhill Cranes belong to the Greater subspecies. Hunting along with habitat changes in the eighteenth and nineteenth centuries reduced Sandhill Cranes in Wisconsin to an estimated 25 breeding pairs. Sandhill Cranes have a different life strategy than most game birds, including longer life span, higher adult survival, lower percentage of juveniles in the population, and lower number of chicks fledged annually. Because of their life strategy, Sandhill Cranes need long periods of time to recover from population declines. It is imperative to have a reliable means to measure population abundance. Many conservationists are concerned that Whooping Cranes could be accidentally mistaken for Sandhill Cranes during a legal hunt. In poor light or bad weather conditions, the silhouette of a Whooping Crane is nearly identical to that of a Sandhill Crane. Sandhill Cranes can cause considerable agricultural damage, but a regulated autumn hunt for Sandhill Cranes would not be an effective deterrent to cranes causing spring crop damage. A non-lethal method, known as Avipel,® is effective at controlling crop damage by cranes. Not all animals need to be managed with a goal of having a sufficient population to be hunted.
- Much more representation from the non-hunting community is urgently needed on this issue. Contact your Senator and Representative with your position statement. Click here or paste the following into your browser <http://legis.wisconsin.gov/Pages/waml.aspx>
- Annual estimates of the percentage of juvenile Sandhill Cranes in the Eastern population are needed.
- More reliable population survey methods are needed, especially for breeding birds.
- Maintain wetland protection policies to ensure ongoing, widespread Sandhill Crane habitat.
- In the event that Wisconsin passes legislation that allows the WDNR to establish a Sandhill Crane hunt, it is critical to have close collaboration among the scientific community, the WDNR, the Mississippi Flyway Council, and the State Legislature to ensure that hunting regulations do not imperil Sandhill Cranes or the experimental population of Whooping Cranes in Wisconsin.
- Whooping Cranes (Grus Americana) and Human Caused Mortality: Considerations Regarding Shooting Occurances and Hunting Seasons (2-19-13)
- Callicott, J.B. 1995. Intrinsic Value in Nature: a Metaethical Analysis: <http://ejap.louisiana.edu/EJAP/1995.spring/callicott.1995.spring.html> (Accessed January 2012)
- Drewien, R.C., W.M. Brown, and W.L. Kendall. 1995. Recruitment in Rocky Mountain Greater Sandhill Cranes and comparisons with other crane populations. Journal of Wildlife Management 59:339-356.
- Hayes, M.A. and J.A. Barzen. 2006. Dynamics of breeding and non-breeding sandhill cranes in south central Wisconsin. Passenger Pigeon 68(4): 345-352.>
- Henika, F.S. 1936. Sandhill cranes in Wisconsin and other lake states. Proc. N. Am. Wildl. Conf. 1:644-646.
- International Crane Foundation. 2012. Crop damage discussion. [Online] <http://www.savingcranes.org/crop-damage-discussion.html> (Accessed November 2012).
- Kennedy, J.J. and J.W. Thomas. 1995. Managing Natural Resources as Social Value. In: A New Century for Natural Resources Management. R. L. Knight and S. F. Bates Eds. Island Press, Washington D.C. <http://www.umass.edu/hd/resources/KennedyValues.pdf> (Accessed August 2012)
- Kruse, K.L., J.A. Dubovsky, and T.R. Cooper. 2012. Status and harvests of sandhill cranes: Mid-Continent, Rocky Mountain, Lower Colorado River Valley and Eastern Populations. Administrative Report, U.S. Fish and Wildlife Service, Denver, CO. 14pp. <http://www.fws.gov/migratorybirds/NewReportsPublications/PopulationStatus.html>
- Leopold, A. 1949. A Sand County Almanac and Sketches Here and There. Oxford University Press, New York. ISBN: 019505928X
- Meine, C. D. and G. W. Archibald (Eds). 1996. The cranes: – Status survey and conservation action plan. IUCN, Gland, Switzerland, and Cambridge, U.K. 294pp. http://www.npwrc.usgs.gov/resource/birds/cranes/gruscana.htm (Accessed Dec 2012).
- Schramm, S., A. Lacy, E. Cullen and J. Barzen. 2010. Protect your corn from cranes. University of Wisconsin Extension Bulletin A3897, Madison, Wisconsin. 4pp.
- Tacha, T.C., S.A. Nesbitt, and P.A. Vohs. 1992. Sandhill crane in A. Poole, P. Stettenheim, and F. Gill, editors. The Birds of North America Monograph 31. The Academy of Natural Sciences, Philadelphia and American Ornithologists’ Union, Washington, D.C. 24 pp.
- [USFWS] U.S. Fish and Wildlife Service. 2012. Important information for waterfowl and sandhill crane hunters. http://www.fws.gov/migratorybirds/CurrentBirdIssues/SandhillCranes/SandhillCraneHunters.htm (Accessed 15 January 2013).
- Van Horn, K., T. White, W. Akins, T. Cooper, K. Kelly, R. Urbanek, D. Holm, D. Sherman, D. Aborn, J. Suckow, K. Cleveland, and R. Brook. 2010. Management Plan for the Eastern Population of Sandhill Cranes. Mississippi and Atlantic Flyway Councils. 36 pp.