Natural Resource Ecology and Management Natural Resource Ecology and Management Publications

2016 Management of Free-Roaming Cassandra M.V. Nuñez Iowa State University, [email protected]

Alberto Scorolli Universidad Nacional del Sur

Laura Lagos Universidad de Santiago de Compostela

David Berman Australian Wild Management Services

Albert J. Kane U.S. Department of Agriculture

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Abstract The modern horse ( caballus) evolved in about four million years ago, dispersing into approximately two to three million years ago. Following this emigration, several occurred in North America, as did additional migrations to Asia and return migrations to North America (see chap. 8). The final North American occurred between 13,000 and 11,000 years ago (Hunt 1992). Eurasian populations persisted, and humans began ~6,000-5 ,500 years ago (Outram et al. 2009) on the western Eurasian (Warmuth et al. 2012) and perhaps on the Iberian Peninsula (Warmuth et al. 2011; Achilli et al. 2012). Today, European free-roaming horse populations can be grouped into three classes: (1) traditional popu· lations, (2) true populations, and (3) introduced populations (for the purposes of conservation management). We consider traditional popu· lations to be free-roaming, long-established horses that are harvested by local people (, , ). Atlantic from the North Iberian Peninsula and the North Atlantic Islands make up a large proportion of these ; some consider them remnants of wild horses living in the region since the (Barcena 2012). Feral populations are domestic animals that were abandoned by local farmers and today live largely unmanaged (, ), and introduced populations are used as components of various habitat restoration proj· ects across Europe (Latvia, the ) (Rewilding Europe 2012). In North America, horses reintroduced in 1493 spread across the plains after escape or release, forming feral herds throughout the and (see chap. 8). In , horses introduced by the Spanish and Portuguese during the sixteenth century spread north into the Pampas, Patagonia, and the mountainous Andean regions. And in , horses introduced by European settlers in 1787 spread into the hills around Sydney and into the north, west, and south as pastoral settlement spread across the continent (see chap. 8). In more recent history, the extirpation of their natural predators has led to even further expansion, resulting in increased human conflict as feral horses more heavily affected , industry, and native .

Disciplines Natural Resources and Conservation | Natural Resources Management and Policy | Terrestrial and Aquatic Ecology

Comments This is a chapter from Nuñez, C.M.V., A. Scorolli, L. Lagos, D. Berman, A. Kane. 2016. Management of freeroaming horses in J.I. Ransom and P. Kaczensky, eds. Wild Equids. The oJ hns Hopkins University Press.

Rights Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The onc tent of this document is not copyrighted.

This book chapter is available at Iowa State University Digital Repository: https://lib.dr.iastate.edu/nrem_pubs/280 Management of Free-Roaming Horses CASSANDRA M.V. NUNEZ, ALBERTO SCOROLLI, LAURA LAGOS, DAVID BERMAN, AND ALBERT J. KANE he modern horse (Equus caballus) evolved in North America about Tfour million years ago, dispersing into Eurasia approximately two to three million years ago. Following this emigration, several extinc­ tions occurred in North America, as did additional migrations to Asia and return migrations to North America (see chap. 8). The final North American extinction occurred between 13,000 and 11,000 years ago (Hunt 1992). Eurasian populations persisted, and humans began domes­ tication ~6,000-5 ,500 years ago (Outram et al. 2009) on the western Eur­ asian Steppe (Warmuth et al. 2012) and perhaps on the Iberian Peninsula (Warmuth et al. 2011; Achilli et al. 2012). Today, European free-roaming horse populations can be grouped into three classes: (1) traditional popu· lations, (2) true feral populations, and (3) introduced populations (for the purposes of conservation management). We consider traditional popu· lations to be free-roaming, long-established horses that are harvested by local people (United Kingdom, Spain, Portugal). Atlantic ponies from the North Iberian Peninsula and the North Atlantic Islands make up a large proportion of these animals; some consider them remnants of wild horses living in the region since the Pleistocene (Barcena 2012). Feral populations are domestic animals that were abandoned by local farmers and today live largely unmanaged (Romania, Russia), and introduced populations are used as components of various habitat restoration proj· ects across Europe (Latvia, the Netherlands) (Rewilding Europe 2012). In North America, horses reintroduced in 1493 spread across the plains after escape or release, forming feral herds throughout the United States and Canada (see chap. 8). In South America, horses introduced by the Spanish and Portuguese during the sixteenth century spread north into the Pampas, Patagonia, and the mountainous Andean regions. And in Australia, horses introduced by European settlers in 1787 spread into the hills around Sydney and into the north, west, and south as pastoral settle­ ment spread across the continent (see chap. 8). In more recent history, the extirpation of their natural predators has led to even further feral horse expansion, resulting in increased human conflict as feral horses more heavily affected livestock, industry, and native wildlife. In this chapter, we focus on the management of free-roaming horse populations occurring in different parts of the United States, South America (in Argentina), Europe (in the United Kingdom, Portugal, Spain, the Netherlands, Romania, and Russia), and Australia (in the Northern 134 History and Management

Number of individuals • < 100 • 101 -1,000

• 1,001-10,000

• 10,001-100,000

e populations considered in this chapter O documented populations not considered in this chapter

Fig. 10.1 The distribution of feral horse populations in the United States (A), South America (8), Europe (C), and Australia• (D). So lid circles represent the populations discussed in this chapter; open circles represent documented populations that are not discussed. Circle size denotes the estimated number of feral horses in the different populations. Sources: (A) Rubenstein and Nunez 2009, BLM 2013b, Coastal Reserve and National Estuarine Research Reserve 2013, National Park Service 2013, Southern States 2013, Ransom et of. 2014a; (B) Pacheco and Herrera 1997, Scorolli and Zoratti 2007, Walton 2008, Scorolli and Lopez Cazorla 2010; (C) Iglesia 1973, Murphy and Gonzalez Faraco 2002, Prieditis 2002, Park Authority 2006, Leblond eta/. 2007, Tupac-Yupanqui eta/. 2011, Matos Vieira Leite 2012, Verderers of the New Forest 2013, Winton eta/. 2013, M. Brewer, unpublished data, M. lnza, unpublished data, L. Lorenzo, unpublished data, 0 . Rosu , unpublished data, Roztocze National Park, unpublished data, N. Spasskaya, unpublished data, van Dierendonck, unpublished data; (D) Dobbie eta/. 1993

Territory) (fig. 10.1). The management strategies em­ ployed in different countries are largely dependent Ecological and Human Conflict upon local laws, logistics, public opinion, the specific Around the world, free -roaming horses can adversely challenges horses pose in an area, and on the social affect the local ecology. In Australia, for example, and cultural importance of free-roaming horses. Sig­ where there are no natural predators, feral horses can nificant variation in management policy exists, and de­ have particularly detrimental impacts, including the pending on where they occur, horse populations are alteration of bird community composition; declines treated differently. Here we discuss human interven­ in reptile and amphibian abundance; soil loss, compac­ tion with free-roaming horses in different regions as tion, and erosion; vegetation trampling; reduction in case studies of the various management options avail­ plant biodiversity; tree death; damage to bog habitats able. Several strategies are explored; however, what is and waterholes; and the expansion of invasive weeds feasible or acceptable often varies depending on the (Nimmo and Miller 2007). region, and our ability to effectively control popula­ Feral horses can have similar impacts in other areas tions with certain methods has not been sufficiently where their natural predators have been extirpated. In evaluated in all areas, making direct comparisons be­ the , for example, the effects of tween methods difficult. feral horse populations on wildlife, fish, plants, soils, Management of Free-Roaming Horses 135

Fig. 10.2 Feral horse in the intertidal zone of Shackleford Banks, North Carolina, USA. Photo by Cassandra M.V. Nunez quality- as well as other resources 2010; de Villalobos et al. 2011), and diminish reproduc­ such as recreation, mining, hunting, and domestic tive success in bird communities (Zalba and grazing- are important considerations, according Cozzani 2004). to the Bureau of Land Management (BLM) (2013b). In Europe, the concern over feral horses' ecologi­ In the eastern United States, concern over feral horse cal impacts varies according to the population classes. occurrence is primarily focused on the animals' eco­ For example, true feral horses are thought to be in­ logical impacts. On Assateague Island, off the coast of vasive, and so there is concern about their environ­ and , for example, an increase in the mental impact. In the Biosphere Reserve in the Letea population from 21 horses in 1965 to 167 horses in 1975 Forest, Romania, feral horses limit forest regeneration led to concern over the animals' potential impact on ( Administra~i Rezerva~iei Biosferei Delta Dunari 2012), the island's ecology. Subsequent studies showed that and on Vodnyi Island, Russia, increases in the horse horses seemed to have little impact on some population (to 419 animals in 2007) have resulted in (Rodgers 1985) but serious impacts on others (Fur­ damage to the steppe community and vegetation deg­ bish and Albano 1994). A similar population increase radation (Prishutova 2010; Minoransky and Uzdenov occurred on Shackleford Banks, a barrier island off 2011). Damage to crops and (Russell 1976; Bar­ the coast of North Carolina. Over 10 years, the horse cena and Hermida 2003; Bento Gorn;:alves et al. 2011 ), population more than doubled, from 100 individuals in horse- vehicle collisions (Bento Gons:alves et al. 2011; 1985 to ~ 220 in 1995 (Rubenstein and Nunez 2009). A Valero et al. 2013; Verderers of the New Forest 2013), survey showed that horse-grazed marshes surrounding decreases to forest regeneration, and the subsequent Shackleford Banks (fig. 10.2) had less vegetation, higher competition with the forestry industry (Magdalena and diversities of foraging birds and crabs, and a lower den­ Vidal 1984; Barcena and Hermida 2003) have also re­ sity and species richness of fishes than did marshes not sulted in considerable conflict over the occurrence of grazed by horses. traditional horse populations in the United Kingdom, In Argentina, high grazing pressure from feral horses Spain, and Portugal. can alter both taxonomic (Loydi and Zalba 2009; Despite conflicts with their environment and with Loydi and Distel 2010) and functional composition of humans, free-roaming horses are often considered to grassland plant communities (de Villalobos and Zalba be an integral component of an area's heritage, cul­ 2010), facilitate invasion by alien species (Loydi et al. ture, and natural history; regardless of where they 136 History and Management occur, they often symbolize freedom, wildness, and open space. In the United States, for example, Con­ Management for Population Control gress mandated that feral horses living on public lands The control of feral horse populations can be achieved be legally designated as "wild" horses that are "living in a variety of ways, including lethal , contracep­ symbols of the historic and pioneer spirit of the West" tion, and the live capture (or collection) and nonlethal (US Congress 1971). As such, it is illegal to hunt, ha­ removal of individuals via their sale, adoption, or main­ rass, or kill feral horses in the United States, grossly tenance in holding facilities. The feasibility and efficacy affecting management options. In Argentina, there is of different methods vary with the areas in which feral considerable debate about how to best manage feral horses occur, both within and between continents. horse populations. In rural areas, horses are some­ times shot to reduce competition with livestock; these Lethal Culling. Lethal culling involves the killing of methods are strongly opposed by those who consider individual animals; individuals can be removed and horses to be pets or cultural icons (C. Zoratti, personal subsequently killed off site or killed on site from the communication). Similarly, some advocates in Austra­ ground or air. Depending upon the objective, animals lia do not support the culling of feral horses; in New may be culled indiscriminately, or they may be taken South , for example, the government imposed a systematically according to age, sex, or reproductive moratorium on aerial culling after photographs of a state. In Argentina, the presence of feral horses in cull sparked public outcry. In European countries, free­ natural protected areas is of particular concern. The roaming horses are valued for their potential roles in management of feral horses in these areas has been wolf conservation (Galicia, Spain: Lagos 2013; L6pez­ sporadic and occasional, however, consisting primarily Bao et al. 2013), fire risk reduction (Spain: Celaya et al. of culling populations occurring in national parks (C. 2012; Rigueiro-Rodriguez et al. 2012), and the preser­ Zoratti, personal communication). An official govern­ vation of steppe (Vodnyi Island, Russia: mental position toward management Spasskaya 2008, 2009). In addition, horses can have was taken in 1995: feral horses needed to be managed cultural significance (Portugal and Wales: Santos and in a systematic manner, but political will and financial Ferreira 2012; Welsh Government 2012) and touristic support were lacking. It was not until 2006 that the value (United Kingdom: Baker 1993; Verderers of the National Parks Administration conducted a diagnosis New Forest 2013). In some areas, free-roaming horses of the "feral horse problem" in the Natural Monument are an important component of local tradition; the Petrified Woods in Santa Cruz province. To date, no horse captures (or roundups) conducted in Galicia and further systemic management actions have been taken. in Dofiana National Park, Spain, for example, are hon­ In practice, the organized management of feral horses ored local events that can attract visitors from around has been conducted at only one site, Tornquist Park, the world (Iglesia 1973; Murphy and Gonzalez Faraco an area under Buenos Aires provincial jurisdiction, and 2002). Regardless of where they occur, it is likely that therefore not related to the National Parks Adminis­ some will view feral horses as an important part of an tration. In 2006 and 2007, 220 feral horses (50% of area's history and ecology while others will view them the population) were live-trapped with mobile corrals as destructive pests. Often the challenge of any man­ (A. Scorolli, unpublished data) (fig. 10.3). The horses agement scheme is to strike a balance between these were transported to the Equine Breeding Division of two opposing viewpoints. the Argentine Army facilities for quarantine and were examined for parasites and contagious diseases. More than 80 horses were sent to slaughter by army equine veterinary decision. A Buenos Aires Province gover­ Free-roaming horse management can take many forms nor's decree declared an eradication objective, but no depending upon its ultimate objective. In many areas, written strategy document or official scientific advice the goal of management is to control populations; in was provided. No efforts were made to monitor the others, it is to reduce conflict with human activity; and efficacy of the removal in terms of long-term reduc­ still in others, it is to maintain or preserve populations. tion in horse numbers or impacts to the park. In 2008, In some situations, the distinctions between these governmental authorities changed, and no further man­ aims can be subtle and may not be mutually exclusive; agement was authorized. conversely, these aims can directly conflict with one In the Delta, Romania, and Vodnyi Island, another. Such differences in the primary goals of mana­ Russia, horse populations grew largely unchecked for gers can result in different management practices. years, but they were controlled to some extent by local Management of Free-Roaming Horses 137

Figure 10.3 Feral horses being collected in a mobile corral in Tornquist Park, Argentina. Photo by Marfa Fernanda Menvielle villagers with occasional culls (Minoransky and Uzde­ horses were damaging the environment and reducing nov 2011; 0. Rosu, unpublished data ). Until recently the productivity of the industry (Dobbie et al. (2 011 ), increases in horse numbers in the Danube 1993), necessitating a reduction in feral horse num­ prompted authorities to conduct extensive roundups bers. But government officers were cognizant of the to capture and slaughter horses (0. Rosu, unpublished potential public opposition if a major culling program data). On Vodnyi Island, culls have been used to en­ were commenced prematurely. The concern was that sure that horse populations are beneficial to the local Australia would follow the example set by the United ecology. Geobotanical studies showed that populations States, where the Wild Free-Roaming Horses and Bur­ of up to 120 individuals can help maintain steppe eco­ ros Act of 1971 placed constraints upon the available systems (Prishutova 2010). To maintain populations control options (US Congress 1971 ). In response, the at this level, the government instituted an adaptive Northern Territory government commenced the first management strategy: each year a variable number major feral horse research program in Australia to help of horses are to be removed, with the precise number seek a solution to the problem (Bowman 1985; Berman determined on the basis of regular monitoring of both 1991 ). The program set out to determine the North­ the population and . In a removal conducted ern Territory feral horse distribution and abundance, in 2012, for example, an equal number of young males economic and environmental impact, and to improve and females were removed and used as bush meat (N. the understanding of feral horse ecology and methods Spasskaya, unpublished data). for management (Bowman 1985; Berman 1991; Dobbie In Australia's Northern Territory, aerial culling from et al. 1993; Bryan 2001 ). helicopter has proven to be an effective management A fixed-wing aerial survey provided an estimate of strategy. In the early 1980s, aerial surveys indicated that 82,000 feral horses in the Alice Springs pastoral district the feral horse population had grown rapidly. Feral (388,000 km') (Graham etal. 1986). A large proportion of 138 History and Management the population (52,000) lived in the mountain ranges, is essential for quantifying feral horse impact and im­ where the rugged terrain and the abundance of natural proving methods for management. These steps must watering points make mustering or trapping difficult be followed if aerial culling is to be used, and engag­ (Berman 1991). A concerted, four-year control effort, ing interest groups is vitally important. Aerial culling combined with drought-induced mortality, resulted in should only be conducted upon approval from these a 77% reduction in the feral horse population living in groups. the mountain ranges of Alice Springs (Low and Hewett Where horses cannot be caught, or where it is im­ 1990). Control activities continued, and in other areas, possible to treat a sufficient number with fertility con­ feral horses were completely removed. At Finke Gorge trol agents, the only current alternative for reducing National Park, for example, a combination of live cap­ their numbers in Australia is shooting from a helicop­ ture and aerial culling removed all feral horses. Indig­ ter. While shooting from helicopter may be relatively enous and nonindigenous landholders, welfare humane (Hampton 2013) and can rapidly reduce feral groups, conservation groups, research scientists, and horse density, it is expensive, wasteful, distasteful to government officers were all actively involved in the much of the public, and by itself may not provide a long­ program (Bryan 2001). The majority of the horses term solution. Managers tend to use shooting from were removed within seven years. The park has now helicopter as a "quick-fix" option, and because it allevi­ been virtually horse-free for over 20 years, and native ates a short-term problem, there appears to be no need wildlife have responded positively. Rock wallabies, to plan for long-term management to avoid the need for example, have expanded their distribution within for future aerial culling. By applying the steps listed the park (Bryan 2001). Feral horses were also almost above and using a combination of the most appropriate completely removed from West MacDonnell Ranges control options, management results could be longer National Park and from the majority of pastoral prop­ lasting. erties held by nonindigenous landholders. Benefits to native fauna and flora and reduced soil erosion were Capture and Use as Food. Traditional populations of At­ reported, as was a reduction in the number of visitor lantic ponies in the Iberian Peninsula and the British complaints about environmental damage in the Na­ Islands are considered free-roaming native horses (or tional Parks (Bryan 2001). ) (Barcena 2012) that are privately owned and Though lethal culling can be effective in reducing traditionally harvested by their owners. These harvests horse numbers, its use remains distasteful to much of serve to control horse numbers, though population the public. Successful management of feral horses, par­ control is not the primary objective. Horses are col­ ticularly when lethal methods are required, may be bet­ lected annually to remove and sell most of the in ter achieved by following the steps listed below, which Galicia (Iglesia 1973), Portugal (Portas et al. 1998), the are based on those from Dobbie et al. (1993). New Forest (Tyler 1972; Ivey 2009; Verderers of the New Forest 2013), Dartmoor (Dartmoor Commoners' 1. Determine distribution, abundance, rate of in­ Council 2013), (Baker 1993), and Wales (Stan­ crease, and movement patterns. ley and Shultz 2012; Winton et al. 2013). 2. Define the problem. What damage are the horses In Galicia, these horse harvests, called curro or rapa das causing? What risks do they pose? bestas (fig 10.4) are an important local event in which tra­ 3. Identify suitable management techniques. ditions like and tail shearing are continued. Histor­ 4. Engage interest groups to decide on management ically, the animals' manes and tails were used for making actions. rope (Iglesia 1973); today, the shearing is custom. In Gali­ 5. Implement agreed actions. cia and Portugal, the foals collected during these harvests 6. Assess the value of management by determining are typically sold for meat and thus provide an incentive change in distribution and abundance and reduc­ for the owners to maintain these populations (J. Calde­ tion in damage or risk. ron, personal communication). Individuals removed 7. Repeat steps 3-6 until an acceptable level of dam­ from the population were once used for transportation, age or risk is achieved. haulage, or work in the farms and mines (Iglesia 1973; 8. Maintain this acceptable level of damage or risk Baker 1993; Barcena and Hermida 2003; Dartmoor Na­ indefinitely with minimal effort or cost. tional Park Authority 2006; Ivey 2009; Peckover and the The first two steps are crucial, though often bypassed. Carneddau Society 2009). These uses have all but These steps require an adequate amount of scientific disappeared, leading to the decline of these populations investigation. A good understanding of local ecology over the last 50 years. Any maintenance of these animals Management of Free-Roaming Horses 139

Fig. 10.4 Inside the curro. foals are separated before adults are captured one at a time to be sheared. The method of capture varies from using a stick with a rope tied in a special knot to the manual restraint of horses on the ground. Photo by Laura Lagos now serves only to conserve the breed and maintain currently in holding (BLM 2013b). These costs included tradition. not only the feeding and watering of these animals, but also the maintenance of their health (box 10.1). More­ Capture and Nonlethal Removal. Capture and nonlethal over, according to BLM, horse populations continue to removal has been used around the world to control increase by - 20% each year (BLM 2013b). Clearly the feral horse populations with varying degrees of suc­ capture, removal, and subsequent maintenance of feral cess. In the United States, the mandate by Congress horses in the western United States does not constitute to protect and also manage feral horse populations a sufficient strategy on its own. such that "a thriving natural ecological balance and Capture and nonlethal removal has also been used multiple-use relationship" is maintained into perpetu­ on Vodnyi Island to maintain population levels that ity (US Congress 1971 ) likely limits the ability of the benefit the local ecology (see "Lethal Culling" above). BLM and Forest Service (FS) to most effectively con­ In 2013 , several foals and yearlings were captured and trol western feral horse populations. The BLM and FS transferred to either stud farms or farmers to control have achieved population limits primarily through the population growth (N. Spasskaya, unpublished data). collection and removal of feral horses from the wild. The efficacy of this removal regarding population con­ Several thousand individuals (usually ranging from trol has not been established. - 7 ,000 to 11,000) are gathered each year and are either adopted by private citizens, held in adoption centers, Contraception. Lethal culling and capture I removal meth­ or placed into long-term holding pastures where they ods are not accepted by much of the public, particularly may be kept for the remainder of their natural lives. in the United States, where it is illegal to hunt feral From 1996 to 2006 , an average of - 8,500 horses per horses or to slaughter them. Such opposition has led to year were removed from the wild (BLM 2013a); the the development of contraceptive agents with an em­ annual percentage of these animals that were adopted phasis on developing vaccines that are effective, safe, decreased dramatically (from 92% to 50%) during that reversible, and that do not result in significant behav­ time period. Given the high costs of owning a horse ioral effects (Kirkpatrick and Turner 1991 ). Research and changing economics, many more animals con­ has largely focused on two methods of action when tinue to be gathered than adopted, and the number of attempting to control fertility in females: suppression animals in holding has become unsustainable (National of gonadotropin secretion (gonadotropin-releasing Research Council 2013). In 2013, the BLM spent $46.2 hormone, or GnRH, ) (Dalin et al. 2002) and million-64% of the total budget for its stimulation of the immune system to block egg fertil­ and Burro Program- solely to maintain the animals ization (porcine zona pellucida, or PZP, vaccination) BOX 10.1 MANAG ING TH E HEA LT H OF FERA L manly used, they generally are not highly efficacious HORSES AN D BURROS in this situation. The best approach to controlling disease outbreaks seems to be to isolate new arrivals Health and welfare are closely intertwined in feral as much as possible when first removed from the horses and burros. By their nature, feral horses and wild, to use a broad vaccination protocol as soon burros are robust and hardy animals, but they are still as possible following capture, and to allow many of susceptible to many of the same diseases and condi­ the respiratory conditions to "run their course" once tions as domestic horses. Feral horses and burros they start to occur. Unfortunately, to some extent, living on the range are not typically affected by the such outbreaks seem inevitable given the ecology of ailments most commonly associated with intensively the disease agents involved and the susceptibility of managed and housed domestic horses (e.g., obesity, the large numbers of animals that must be handled early-onset osteoarthritis, hoof abscesses, lamini- during the transition from free-roaming to domestic tis, colic), but injuries and disease do occur. Apart life. Fortunately, while morbidity may be high, these from the effects of starvation when forage or water conditions are usually self-limiting without treat­ resources are inadequate, poorly healed old injuries, ment, and serious complications and mortality due to and manifestations of developmental orthopedic pneumonia or internal abscesses are rare. Treatment disease seem to be the most common serious condi­ of individual animals housed in a group setting is tions seen on the range. not without added risk and stress associated with One of the myths about feral horses and burros is handling, so this type of treatment is usually reserved that they are somehow inherently more resistant to for those individuals who appear to be suffering from disease than their domestic counterparts. While it is complications of the upper respiratory . true that the effective contact rate for disease spread Following the transition to domestic life through between individuals may be low when they live in adoption or sale to private ownership, the health small, widely dispersed bands, infectious diseases problems faced by feral horses and burros are largely do occur in free-roaming animals as well as those the same as those of domestic horses and burros. removed into captivity. Internal parasites (ascarids, Some of the desirable hoof shape characteristics of Oxyuris equi, and large strongyles) are common in the feral horse change when removed from the range horses fresh off the range. Parasite burdens can be into a captive environment, but used as quite heavy in adolescents and adults, such as heavy horses seem to be as athletic as any similarly ascarid burdens seen in recently removed feral horses built domestic horse. They also tend to be long lived of all ages, including adults that one might expect to and remain sound for many years when they make have developed immunity. the transition to domestic life. Without question, the most common and chal­ lenging problem facing feral horses once they are removed from the range and held in corrals is infec­ tious upper respiratory disease. Viral agents (equine herpes and influenza viruses) are problems, but upper respiratory infections caused by Streptococcus equi and S. zooepidemicus are most common. Exposure levels and disease spread seem low in the wild, but the real problems occur when animals are removed from the wild and congregated in captivity. Most of the animals are immunologically na'ive to these infectious agents when they are captured. Combined with the stress of adapting to captivity, they become particularly susceptible to . Complete isola­ tion is difficult in large dry-lot facilities, and exposure to the agents that typically cause infectious upper respiratory disease in the domestic world seems inevitable. While vaccines for these agents are com- Photo by V. V. Vita Management of Free-Roaming Horses 141

(Sacco 1977). GnRH vaccines are generally effective at serve population-level effects, however, apparent an­ achieving infertility in domestic mares; however, sev­ nual population growth rate was only 4-9% lower in eral applications can be necessary to induce ovarian posttreatment years when compared to pretreatment inactivity (Dalin et al. 2002; Stout and Colenbrander years. Moreover, population growth was positive and 2004), and revaccination is necessary to maintain in­ still increased steadily every year that a management re­ fertility (Killian et al. 2008). In the year following treat­ moval was not conducted (Ransom 2012). Nevertheless, ment, GnRH contraception only minimally affected managers potentially saved the US government ~$1.4 time budget behaviors and did not significantly affect million during the study by combining horse removals the reproductive behavior or physical condition of with PZP contraception (Ransom 2012). treated females in a population of feral horses living in In the eastern United States, the National Park Ser­ Theodore Roosevelt National Park in , vice (NPS), the Foundation for Shackleford Horses, USA (Ransom et al. 2014a). Similarly, PZP has been and the Corolla Wild Horse Fund currently use PZP shown to be safe, effective, and theoretically has mini­ agents to manage four feral horse herds occurring on mal side effects (Turner et al. 2001, 2002). PZP use is barrier islands. These populations include the horses not practical in all populations (Killian et al. 2008), how­ living on Assateague Island, off the coast of Maryland, ever; annual revaccination is necessary to ensure infer­ and those occurring on Shackleford Banks, Carrot tility (Turner et al. 2001), the time required to reach Island, and the Currituck , off the coast desired population levels can be substantial (Conserva­ of North Carolina. Population numbers have largely tion Breeding Specialist Group 2006), it can indirectly been controlled to desired levels at these sites (Kirkpat­ affect animal behavior and physiology (Nunez et al. rick 1995; S. Stuska, unpublished data). Despite PZP's 2009, 2010; Ransom et al. 2010), and its population­ potential drawbacks (Nunez et al. 2009, 201 O; Madosky level efficacy may be reduced owing to local ecological et al. 2010; Ransom et al. 2010, 2013) and the uncer­ feedback mechanisms (Ransom et al. 2014b). tainty regarding its efficacy in large, open populations The newly developed GonaCon and SpayVac vac­ (Ransom et al. 2014b), successes in eastern populations, cines prevent pregnancy by targeting GnRH and the the potential fiscal implications, and the promising re­ zona pellucida, respectively, but single applications sults with SpayVac (Killian et al. 2008) have made zona are thought to be effective over multiple years. Killian pellucida-directed contraception of feral mares an at­ et al. (2008) showed that rates of conception for con­ tractive option for the management of feral horses in trol mares were significantly higher than for SpayVac­ the western United States. and GonaCon-treated mares. In addition, SpayVac was more effective at achieving infertility than GonaCon in Management for the Reduction of Human-Horse Conflict. all years subsequent to treatment. Average rates of con­ In several European countries, the high occurrence traception over four years of study were 87.25% (range of horse-vehicle collisions has influenced the man­ = 83-100%) and 63.50% (range= 40-93.75%) for Spay­ agement of free-roaming horse populations. For ex­ Vac and GonaCon, respectively. Gray et al. (2011) did not ample, Galicia registered an average of 75 collisions find such differences between SpayVac and GonaCon-B per year between 2006 and 2010 (Valero et al. 2013). in a population of feral horses occurring on the Virginia Similarly, in the New Forest, 69 and 64 accidents were Range, southwest of Reno, Nevada, USA. In addition, registered in 2011 and 2012, respectively (Verderers of though treated mares were less likely to conceive than the New Forest 2013). In Galicia, increased fencing and control mares, contraception rates for animals treated regulations ensuring compensation to drivers (by horse with SpayVac were lower than in Killian et al.'s (2008) "owners") are the only measures in place to mitigate study, averaging 59.66% (range = 50-63%) over three this issue. These policies fail to acknowledge the im­ years; contraception rates were similar with GonaCon­ portance of combined approaches, including increased B, averaging 62.66% (range= 58-69%). Contraceptive public awareness and drivers' education, to the reduc­ treatment did not significantly affect sex ratio, foal tion of wildlife-related traffic accidents (Langbein et al. survival, or birthing season (Gray et al. 2011). 2011). Conversely, managers in New Forest are taking The BLM has administered both liquid and pelleted several steps to reduce horse-related accidents (New PZP to various horse herds in Montana, Wyoming, and Forest National Park Authority 2013; Verderers of the Colorado. The ability to sufficiently control population New Forest 2013). They encourage the police to en­ growth with PZP has not been studied systematically in force a speed limit of 40 miles per hour for all unfenced open populations (Ransom et al. 2014b). In three closed roads and collaborate with the administration of the populations where it was possible to scientifically ob- county highway to develop more effective signage. In 142 History and Management addition, there is an effort to increase pony visibility; Their history of domestication makes it difficult for roadside vegetation is trimmed, and high-risk horses some members of the public to truly consider these that commonly graze on the road side are fitted with horses "wild" animals. Several groups believe that if reflective collars. horses are to be introduced to an area, they ought to be provided with food, water, and shelter (Slaukstins 2002; Management to Maintain and Preserve Populations. De­ Vera 2009). Such public concern has largely driven the spite the need to control feral horse numbers in some management policies regarding these populations. For areas, those same animals are sometimes fed to sup­ example, initially, a minimal intervention policy, includ­ plement their diet in poor environmental conditions. ing the culling of dying animals to simulate predation Feral horse populations on Vodnyi Island have been (van Dierendonck 2012 ), was adopted in the Oostvaard­ fed during particularly severe winters (N. Spasskaya, ersplassen. Later, the International Committee on Man­ unpublished data), against scientific recommendations agement of the Oostvaardersplassen (ICMO) adopted (Minoransky and Uzdenov 2011). Similarly, Four Paws, new management policies to satisfy the public's animal an international organization, has been welfare concerns. Research was to be conducted on the providing winter supplements to the population, the population was to be more closely mon­ population since 2010 (0. Rosu, personal communica­ itored, animals were provided shelter access, and those tion). Supplementing animals in this way can lead to unlikely to survive the winter were culled to prevent population increases, further necessitating population suffering (ICMO 2006). control measures; however, the public's notion that In 2010, the ICMO reevaluated the culling policy horses are a domestic species and therefore need to be to more accurately predict the likelihood of animal cared for (Slaukstins 2002; Vera 2009) can result in this survival, creating the Early Reactive Culling Proto­ type of conflicting management practice. col (ICMO 2010). This protocol considers individual behavior, individual condition score, population den­ sity, food availability, time of year, and environmental Horses as Conservation Management Tools conditions to make more informed culling decisions; Herbivore grazing can be used as a conservation tool animals unlikely to survive are thus culled in an earlier to decrease habitat management intensity; it is inexpen­ stage of decline to minimize suffering (ICMO 2010; sive, environmentally friendly, and produces mosaic­ van Dierendonck 2012). like patches, creating more natural landscapes (Kampf More recent horse introduction projects, such as 2002). Throughout Europe, several programs have in­ those instituted in the United Kingdom and Spain, troduced horses to increase biodiversity (Murray 2008; have yet to encounter such issues. In other areas where Rewilding Europe 2012) and to maintain (Vulink et al. endangered breeds have been introduced, increases in 2010), improve (Forder 2006), or preserve various habi­ population numbers are integral to the reestablish­ tats (Cosyns et al. 2001), thereby making them more ment of the breed (Rewilding Europe 2012). In areas suitable for other species. Perhaps the most well-known instituting rewilding projects, more natural, density­ introduction is at the Oostvaardersplassen, a 56-km2 dependent processes, including predation and intraspe­ fenced area in the Netherlands. , a hearty breed cific competition, are expected to control populations. of horses originating in , were introduced to the Regardless, when semidomestic animals are released area in 1984 (Heck cattle had been introduced in 1983) into the wild, population control may become neces­ to help maintain greylag goose (Anser anser) and bar­ sary (Foundation for Restoring European Ecosystems nacle goose (Branta leucopsis) habitat. Grazing by horses 2013), especially in areas that do not contain predators. and cattle shortens the and slows vegetation succession, making the area suitable for the geese and a number of other bird species. In addition, the horses Current Developments may attract , resulting in social and economic Today, the management of free-roaming horses con­ benefits for local communities, landowners, and stake­ tinues to be a "work in progress." In 2011, for ex­ holders (Rewilding Europe 2012). A similar program ample, the BLM approached the National Academy of has been instituted in Latvia at Lake Pape (Slaukstins Sciences to request an independent technical evalua­ 2002; Schwartz 2005), as have several in by or­ tion of the science, methodology, and technical deci­ ganizations such as the Royal Society and Protection sion making of their Wild Horse and Burro Program. of Birds, the National Trust, the Forestry Commission, The panel recommended the reconciliation of manage­ and the Wildlife Trusts (Murray 2008). ment practices with feral equid population ecology; Management of Free-Roaming Horses 143 the use of more comprehensive population models both the time and funding necessary to collect the to forecast program costs and evaluate management relevant data are considerably less than that typically alternatives for animals on the range and in holding needed to collect data for traditional demographic facilities; and suggested that the most promising fer­ models. This new model has been partially validated tility control methods for feral horses and burros are with data from 2011 (Scorolli 2012) and is currently chemical vasectomy for males and the GonaCon and being refined. In addition to these developments, the PZP vaccines for females (National Research Council problem of invasive alien species (IAS), including feral 2013). But ~95% of horse herds managed by the BLM domestics, was considered at the Argentine National consist of open populations, where immigration and Expert Workshop on Alien Fauna in 2011 and 2012. A emigration cannot be controlled. In such populations, national strategy on the IAS project is currently under the identification of individual animals for monitoring way, promising further progress toward achieving vi­ or treatment is not possible with the technologies cur­ able solutions for the control of feral horse populations rently available to the BLM (National Research Council in Argentina. 2013). These limitations make the panel's recommen­ In different areas of Spain, regional governments dations exceedingly difficult to carry out. In addition, seek to mitigate human-horse conflicts with tra­ contraceptive agents are unlikely to effectively control ditional populations through the tracking of horse such large, open populations (Ransom et al. 2014b). Yet "owners." This tracking ensures that those affected by the fact remains that current management practices the horses can seek damage compensation. Spanish re­ are unsustainable and may actually promote higher gional governments are applying existing European do­ population growth rates in some circumstances. The mestic horse regulations, which stipulate that all equids BLM removals typically keep feral horse numbers be­ have an identification document (or passport) and that low levels that would be affected by food limitation they be implanted with a microchip linked to the docu­ and density dependence. Adverse effects to pregnancy ment and to a database containing details about the rates, female fecundity, and survival rates associated animals' owners (European Commission 2008). This with food competition and density dependence are measure is incompatible with the existence of feral therefore prevented, potentially resulting in increased horse populations and puts traditional populations and population growth (National Research Council 2013). the customary methods used to manage them at risk of Legislation that would put the task of managing feral extinction (Lagos 2013; Lopez-Bao et al. 2013). Article horse populations in the hands of states rather than 7 of the regulation, an exemption to microchip mea­ the federal government has been considered by the US sure, takes free-roaming equids into account, stating Congress (US Congress 2014). It is difficult to predict that "the competent authority of the EU countries may how such a policy shift might affect feral horse man­ decide that constituting defined populations agement in the United States; however, it will likely living under wild or semi-wild conditions in certain ar­ make an already piecemeal policy even less cohesive, eas, including nature reserves, to be defined by that au­ and as with most policy regarding feral horses, it is thority, shall be identified only when they are removed likely to result in considerable controversy. from such areas or brought into domestic use." This In Argentina, collaborations between governmen­ exemption has been applied in Wales for their free­ tal agencies and university researchers are developing roaming horse populations in Carneddau (Welsh Gov­ more viable solutions for their feral horse populations ernment 2012) and in England, in accordance with the (A. Scorolli, unpublished data). A long-term research Horse Passports Regulation of 2009 (UK Secretary of project (1995 to present) has been investigating the de­ State 2009), for the Exmoor, Dartmoor, and New For­ mography and social organization of the feral horse est populations, but it has not been applied in Spain or population in Tornquist Park. A model has been devel­ Portugal. Fertility control methods are currently being oped in which the proportion of adult females with dif­ considered in Europe as well. Four Paws has developed ferent body condition scores (collected at winter's end, an action plan to manage the horses in the Danube when animals are typically in the poorest condition) is Delta, which includes the contraception of females to used to predict the population's likelihood of reaching help control population numbers (Rosu 2013). carrying capacity, the potential population growth, and In Australia, aerial culling was considered by many foaling rates (Scorolli 2012). Outcomes of the model to be the most humane method for reducing horse may help inform management strategies, as the afore­ numbers by the end of the 1980s. The animals were mentioned factors can be used to make assumptions often found in remote and rugged areas, and provided about the horses' environmental impact. Moreover, that highly trained, experienced officers conducted the 144 History and Management culling, adhering to strict operational guidelines (Bryan occur necessitate their management. From the data pre­ 2001), this method was (and continues to be) highly sented here, it is clear that there is no single best manage­ supported. Aerial culling has continued in central Aus­ ment strategy. In the western United States, taxpayers tralia, with 16,254 feral horses being shot from heli­ spend tens of millions of dollars each year to maintain copter between 2002 and 2013 (G. Edwards, personal the nearly 50,000 feral horses in holding; in the eastern communication). Little management of feral horses United States, horses are controlled primarily with con­ has occurred on land held by indigenous owners in traception, potentially altering their behavior and repro­ central Australia, and large populations of feral horses ductive physiology. In South American countries, there remain in these areas. is little to no organized management of feral horses, save Despite the general acceptance of culling, conflict for those occurring in Argentina, where new collabora­ can and does arise in response to lethal management tions seem promising. In European countries, the situa­ methods. Community conflict most often arises when tion is different, as free-roaming horses are sometimes management actions occur without supporting local considered a native species; nevertheless, people have research and public consultation. In October 2000, for different attitudes regarding traditional, feral, and in­ example, a culling operation was conducted in Guy troduced horse populations, ranging from cultural icon Fawkes River National Park after a bushfire destroyed and essential keystone species to problem animal; these the primary food source for a large population of feral diverse attitudes have resulted in inconsistent manage­ horses. Six hundred feral horses were shot from heli­ ment regimens across nations. Finally, in Australia, feral copter, resulting in significant community opposition, horses adversely affect the native ecosystems for which and as a result the New South Wales minister for the they are not adapted. Although scientists have developed environment commissioned an independent review to seemingly humane ways to reduce populations, it is clear examine the Guy Fawkes operation. While the opera­ from the information presented here that lethal culls are tion was found to be well planned, "it would have been not a panacea and need to be conducted in conjunction prudent for the Service to have sought the involvement with other measures to ensure consistent population­ and cooperation of the RSPCA in planning and car­ level declines. Overall, managers have limited tools with rying out the operation, with emphasis on both the which to control feral horse populations; politics and welfare of the horses and the significant ill-effects of public opinion limit these options even further. The his­ the large horse herd on native flora and fauna if noth­ tory of horse domestication complicates the issue, blur­ ing was done, and that local land owners should also ring the line between wild and domestic animal. have been involved in some way from the outset, to The management of free-roaming horses is and ensure that they knew what was happening and why" will continue to be a difficult task. With every decision, (English 2000). managers and policymakers need to consider the effi­ Studies required to improve feral horse manage­ cacy, feasibility, costs, and benefits of different strate­ ment at Guy Fawkes River National Park have been gies; the potential effects to horse health and welfare; conducted since the culling operation (Schott 2005; and the impacts of public opinion on management Dawson et al. 2006; Vernes et al. 2009; Lenehan 20ll), implementation. Without natural predators to control and a successful capture and rehoming program has feral horse populations, almost any method we choose been established. The Guy Fawkes cull in 2000 pro­ will likely necessitate ongoing human intervention. A vided the impetus for more thorough planning of feral balance between the costs and benefits, to the surround­ horse population management in many parts of Aus­ ing ecology and both feral horse and human popula­ tralia. Preparation of formal management plans involv­ tions, is difficult to strike, but with sufficient study of ing community interest groups may help overcome the and demographics, and with clear, pre­ problems experienced at Guy Fawkes and help ensure cise definitions of the problems that horses pose to a that all appropriate preparations are conducted before region, we can increase the likelihood of effective and action is taken. While these developments are encour­ ethical management in diverse geographic regions. aging, long-term solutions have yet to be achieved. ACKNOWLEDGMENTS The authors sincerely thank all those who generously Conclusion contributed both their time and knowledge to this ef­ There are ~l.5-2 million free-roaming horses around fort-there are too many to name here. Their help the world. The extinction or extirpation of their natural undoubtedly made this chapter a more complete and predators in nearly all of the regions where feral horses accurate review of feral horse management around the Management of Free-Roaming Horses 145 world, both past and present. The authors also want Publication No. 132. Wageningen Academic, Wageningen, to thank Jason Ransom and Petra Kaczensky, whose Netherlands. initiative, hard work, and tenacity made the meeting Conservation Breeding Specialist Group. 2006. Horses of As­ in Vienna a success and this book possible. Thanks are sateague Island population and habitat viability assessment workshop, Berlin, MD. National Park Service, Washington, also owed to Jason and Petra, in addition to two anony­ DC, USA. mous reviewers, for their thoughtful consideration of Cosyns, E., T. Degezelle, E. Demeulenaere, and M. Hoffmann. an earlier version of this chapter. 2001. Feeding ecology of horses and donkeys in Bel­ gian coastal dunes and its implications for nature manage­ ment. Belgian Journal of Zoology 131:111-118. REFERENCES Dalin, A.M., 0. Andresen, and L. Malmgren. 2002. Immuni­ Achilli, A., A. Olivieri, P. Soares, H. Landoni, B.H. Kashani, zation against GnRH in mature mares: Antibody titres, U.A. Perego, S.G. Nergadze, V Carossa, M. Santagostino, ovarian function, hormonal levels and oestrous behaviour. and S. Capomaccio. 2012. Mitochondrial genomes from Journal of Series A 49:125-131. modern horses reveal the major haplogroups that under­ Dartmoor Commoners' Council. 2013. Pony drifts. Dartmoor went domestication. Proceedings of the National Academy Commoners' Council, Tavistock, Devon, UK. Available at of Sciences of the USA 109:2449-2454. www.dartmoorcommonerscouncil.org.uk/. Administrati Rezerva~iei Biosferei Delta Dunari. 2012. The Dartmoor National Park Authority. 2006. The Dartmoor situation of abandoned horses in Letea Forest Area of the ponies factsheet. Dartmoor National Park Authority, New­ Danube Delta biosphere reserve. Available at www.self­ ton Abbot, Devon, UK. Available at www.dartmoor-npa willed-land.org. uk/ articles I Horses_from_Letea.pdf. .gov.uk. Baker, S. 1993. Survival of the fittest: A natural history of the Dawson, M.J., C. Lane, and G. Saunders. 2006. Proceedings of . Exmoor Books, Exeter, UK. the National Feral Horse Management Workshop. Invasive Barcena, F. 2012. Garranos: Os p6neis selvagens (Equusferus sp.) Animals Cooperative Research Centre, Canberra, ACT, do norte da Peninsula Iberica. Pages 75-96 in Livro de Atas: Australia. I Congresso Internacional do Carrano. Arcos de Valdevez, de Villalobos, A.E., and S.M. Zalba. 2010. Continuous feral Portugal. horse grazing and grazing exclusion in mountain pampean Barcena, F., and R. Hermida. 2003. Mamiferos de Galicia. Pages grasslands in Argentina. Acta Oecologica: International 432-579 in R. Otero Pedrayo (Ed.), Enciclopedia Galega. Journal of Ecology 36:514-519. Editorial Novos Vieiros, A Corufia, Spain. de Villalobos, A.E., S.M. Zalba, and D.V Pelaez. 20ll. Pinu.s Bento Gon~alves, A., A. Vieira, F. Ferreira Leite, L. da Vinha, halepensis invasion in mountain pampean grassland: Effects and P. Alexandra Malta. 2011. Evaluation and implica­ of feral horses grazing on seedling establishment. Environ­ tions of free-ranging garrano horses in the risk of forest mental Research 111:953-959. fires: The study case of Vieira do Minho Municipality Dobbie, W.R., D. Berman, and M. Braysher. 1993. Managing (Portugal). Pages 53-77 in D.A. Boehm (Ed.), Forestry: vertebrate pests: Feral horses. Australian Government Pub­ Research, ecology and policies. Nova Science, New lishing Service, Canberra, ACT, Australia, Available at www York, USA. .feral.org.au I managing-vertebrate-pests-feral-horses-2. Berman, D. 1991. The ecology of feral horses in central Aus­ English, A. 2000. Report on the cull of feral horses in Guy tralia. Thesis, University of New England, Armidale, NSW, Fawkes River National Park in October 2000. University of Australia. Sydney, Sydney, NSW, Australia. BLM. Bureau of Land Management. 2013a. Wild horse and European Commission. 2008. Commission regulation no. 504/ burro statistics. Washington, DC, USA. Available at www 2008 of June 6, 2008, implementing Council Directives 90/ .wildhorseandburro.blm.gov I statistics I index.htm. 426/ EEC and 90/ 427 /EEC as regards methods for the iden­ BLM. Bureau of Land Management. 2013b. Wild horse and tification of equidae. Brussels, Belgium. Available at http: I I burro quick facts. Washington, DC, USA. Available at www ec.europa.eu/ environment/life I index.htm. .him.gov I wo I st/ en/ prog/ whbprogram/ history_and_ Forder, V 2006. Conservation grazing: Konik horse, Euro­ facts/ quick_facts.html. pean beaver and wild boar. Wildwood Trust, Herne , Bowman, A. 1985. Analysis of aerial survey data from Alice Kent, UK. Available at www.wildwoodtrust.org/files/ Springs district and implication for feral horse manage­ conservation-grazing.pd[ ment. B Natural Resources Project, University of New Foundation for Restoring European Ecosystems. 2013. Natural England, Armidale, NSW, Australia. grazing: Wild and semi-wild animals as landscape archi­ Bryan, R. 2001. Humane control of feral horses in central Aus­ tects. Foundation for Restoring European Ecosystems, tralia. Paper presented at the 12th Australasian Vertebrate Beuningen, Netherlands. Available at www.freenature.eu/ Pest Conference, Melbourne, VIC, Australia. free/ download/ documenten/ natuurlijke-begrazing_uk.pdf Celaya, R., L.M.M. Ferreira, U. Garcia, R. Rosa Garcia, and Furbish, C.E., and M. Albano. 1994. Selective herbivory and K. Osoro. 2012. Heavy grazing by horses on heathlands plant community structure in a mid-Atlantic marsh. of different botanical composition. Pages 219-226 in M. Ecology 75:1015-1022. Saastamoinen, M.J. Fradinho, A.S. Santos, and N. Mira­ Graham, A., K. Johnson, and P. Graham. 1986. An aerial survey glia (Eds.), Forages and grazing in horse nutrition. EAAP of horses and other large animals in the Alice Springs and 146 History and Management

Gulf regions. Conservation Commission of the Northern in Camargue, France. Preventive Veterinary Medicine Territory, Alice Springs, NT, Australia. 79:20-31. Gray, M.E., D.S. Thain, E.Z. Cameron, and L.A. Miller. 2011. Lenehan,]. 2011. Ecological impacts of feral horses in grassy Multi-year fertility reduction in free-roaming feral horses woodland and open-forest gorge country in a temperate­ with single-injection immunocontraceptive formulations. subtropical wilderness. Thesis, University of New England, Wildlife Research 38:475-481. Armidale, NSW Australia. Hampton,]. 0. 2013. Assessment of the humaneness of feral L6pez-Bao,J.V, V Sazatornil, L. Llaneza, and A. Rodriguez. horse helicopter shooting operations in the Northern Terri­ 2013. Indirect effects on heathland conservation and wolf tory: Tempe Downs. Ecotone Wildlife Veterinary Services, persistence of contraditory policies that threaten tradi­ Canberra, ACT, Australia. tional free-ranging horse husbandry. Conservation Letters Hunt, K. 1992. Horse evolution. Page 205 in B.j. MacFadden 6:448-455. (Ed.), Fossil horses: Systematics, paleobiology, and evolu­ Low, WA., and M.R. Hewett. 1990. Aerial survey of horses tion of the family equidae. Cambridge University Press, and other large animals in the central ranges of the Alice New York, USA. Springs district. Unpublished report to the Conservation ICMO. International Committee on the Management of Large Commission of the Northern Territory, Alice Springs, NT, Herbivores in the Oostvaardersplassen. 2006. Reconciling Australia. nature and human interests. The Hauge, Netherlands. Loydi, A., and R.A. Distel. 2010. Floristic diversity under ICMO. International Committee on the Management of different intensities of large herbivore grazing in mountain Large Herbivores in the Oostvaardersplassen. 2010. grasslands of the Ventania System, Buenos Aires. Ecologia Natural processes, animal welfare, moral aspects and Austral 20:281-291. management of the Oostvaardersplassen. The Hague, Loydi, A., and S.M. Zalba. 2009. Feral horses dung piles as Netherlands. potential invasion windows for alien plant species in natural Iglesia, P. 1973. Los caballos gallegos explotados en regimen de grasslands. Plant Ecology 201:471-480. libertad o caballos salvajes de Galicia. Thesis, Facultad de Loydi, A., R.A. Distel, and S.M. Zalba. 2010. Large herbivore graz­ Veterinaria, Universidad Complutense de Madrid, Madrid, ing and non-native plant invasions in montane grasslands of Spain. central Argentina. Natural Areas journal 30:148-155. Ivey,]. 2009. Report on New Forest traditions: Our New Forest. Madosky,j.M., D.I. Rubenstein,].]. Howard, and S. Stuska. A living register of language and traditions. New Forest 2010. The effects of immunocontraception on harem Centre, Lyndhurst, , UK. Available at www.new fidelity in a feral horse (Equus caballus) population. Applied forestcentre.org. uk/ uploads I publications I 65. pdf Animal Behaviour Science 128:50-56. Kampf, H. 2002. Nature conservation in pastoral landscapes: Magdalena, R., and T. Vidal. 1984. Los garranos galaicos. Challenges, chances and constraints. Pages 15-38 in B. Quercus 15:35-38. Redecker, P. Finck, W Hardtle, U. Riecken, and E. Schro­ Matos Vieira Leite,]. 2012. A rai;a Equina Garrana. Pages 30-49 der (Eds.), landscapes and nature conservation. in N. Vieira de Brito and G. Candeiras (Eds.). Proceedings Springer-Verlag, Berlin, Germany. of the Livro de Atas, I Congresso Internacional do Garrano Killian, G., D. Thain, N.K. Diehl,]. Rhyan, and L. Miller. 2008. [in Portuguese]. Arcos de Valdevez, Portugal. Four-year contraception rates of mares treated with single­ Minoransky, VA., and A.M. Uzdenov. 2011. Feral horses of injection porcine zona pellucida and GnRH vaccines and Vodnyi Island (Manich-Gudilo Lake, Rostov Region, Rus­ intrauterine devices. Wildlife Research 35:531-539. sia). News Biosphere Reserve. [In Russian.] Askania Nova Kirkpatrick,J.F. 1995. Management of wild horses by fertility 13:135-145. control: The Assateague experience. Monograph NRSM- Murphy, M.D., and J.C. Gonzalez Faraco. 2002. Las yeguas 95/26. US National Park Service, Washington, DC, USA. marismefias de Dofiana: Naturaleza, tradici6n e identidades Kirkpatrick,j.F., andj.W Turner.1991. Reversible contracep­ sociales en un espacio protegido. Revista de Dialectologia y tion in nondomestic animals. journal of and Wildlife Tradiciones Populares 57:5-40. Medicine 22:392-408. Murray, D.A. 2008. Conserving Britain's last wild ponies. Geo­ Lagos, L. 2013. Ecologia de! lobo (Canis lupus), de! poni salvaje graphical Magazine 80:48-53. (Equus ferus atlanticus) y de! ganado vacuno semiextensivo National Park Service. 2013. Assateague Island National (Bos taurus) en Galicia: Interacciones depredador-presa. Seashore. Washington, DC, USA. Available at www Thesis, Universidad de Santiago de Compostela, Santiago .assateagueisland.com I island_info I assateague_info.htm. de Compostela, Spain. National Research Council. 2013. Using science to improve the Langbein, J., R. Putman, and B. Pokorny 2011. Traffic collisions BLM Wild Horse and Burro Program: A way forward. Na­ involving deer and other ungulates in Europe and available tional Academies Press, Washington, DC, USA. measures for mitigation. Pages 215-259 in R. Putman, M. New Forest National Park Authority. 2013. Animal acci­ Apollonio, and R. Andersen (Eds.), Ungulate management dents. Lymington, Hampshire, UK. Available at www in Europe: Problems and practices. Cambridge University .newforestnpa.gov. uk/ info I 20094 I commoning/ 40 I Press, Cambridge, UK. animal_accidents I 3. Leblond, A., A. Sandoz, G. Lefebvre, H. Zeller, and D.J. Bicout. Nimmo, D.G., and K.K. Miller. 2007. Ecological and human 2007. Remote sensing based identification of environmen­ dimensions of management of feral horses in Australia: A tal risk factors associated with West Nile disease in horses review. Wildlife Research 34:408-417. Management of Free-Roaming Horses 147

North Carolina Coastal Reserve and National Estuarine Rodgers, R.B. 1985. Assateague Island National Seashore feral Research Reserve. 2013. Rachel Carson. Available at www pony management plan. Assateague Island National Sea­ .nccoastalreserve.net/ web/ crp I rachel-carson. shore, Berlin, MD, USA . Nunez, C.M.V.,j.S. Adelman, C. Mason, and D.I. Rubenstein. Rosu, 0. 2013. Research plan: Evaluation of immunocon­ 2009. Immunocontraception decreases group fidelity in a traception on the Letea feral horses following the active feral horse population during the non-breeding season. Ap­ immunization with porcine zona pellucida. Page 16 in Vier plied Animal Behaviour Science 117:7 4-83. Pfoten-Four Paws. Universitatea de ~tiinte Agronomice ~i Nunez, C.M.V.,j.S. Adelman, and D.I. Rubenstein. 2010. Im­ Medicina Veterinara Bucure~ti, Vier Pfoten, Romania. munocontraception in wild horses (Equus caballus) extends Roztocze National Park. 2013. Roztocze National Park, Poland. reproductive cycling beyond the normal breeding season. Available at www.roztoczanskipn.pl. PLoS ONE 5:el3635. Rubenstein, D.l., and C.M.V. Nunez. 2009. Sociality and Outram, A.K., N.A. Stear, R. Bendrey, S. Olsen, A. Kasparov, V. reproductive skew in horses and . Pages 196-226 Zaibert, N. Thorpe, and R.P Evershed. 2009. The earliest in R. Hager and C.B. Jones (Eds.), Reproductive skew in horse harnessing and milking. Science 323:1332-1335. vertebrates: Proximate and ultimate causes. Cambridge Pacheco, M.A., and E.A. Herrera. 1997. Social structure of feral University Press, Cambridge, UK. horses in the llanos of Venezuela. Journal of Mammalogy Russell, V. 1976. New Forest ponies. David & Charles, Newton 78:15. Abbot, Devon, UK. Peckover and the Carneddau Pony Society. 2009. First annual Sacco, A.G. 1977. Antigenic cross-reactivity between human and sale by public auction of approx 100 Carneddau Welsh pig zona pellucida. Biology of Reproduction 16: 164-173. Mountain pony foals, youngstock and draft mares. Grazing Santos, A.S., and L.M.M. Ferreira. 2012. The Portuguese Car­ Animals Project, Stoneleigh Park, Warwickshire, UK. Avail­ rano breed: An efficient and sustainable production system. able at www.grazinganimalsproject.org.uk/news/first_ Forages and Grazing in Horse Nutrition 132:481-484. public_auction_of_carneddau_ponies_tyn_llwyfan_5th_ Schott, C. 2005. Ecology of free-ranging horses in Northern december_2009.html. Guy Fawkes River National Park NSW, Australia. Thesis, Portas, M.C.P.,j.M. Vieira Leite, andJ.J.D. Oliveira e Sousa. University of New England, Armidale, NSW, Australia. 1998. A ra~a Garrana: Um contributo para o seu estudo. Schwartz, K.Z.S. 2005. Wild horses in a "European wilderness": Veterinaria Tecnica Dezembro 98:18-26. Imagining sustainable development in the post-Communist Prieditis, A. 2002. Impact of wild horses herd on vegetation countryside. Cultural Geographies 12:292-320. at Lake Pope, Latvia. Acta Zoologica Lituanica 12 Scorolli, A.L., and C. Zoratti. 2007. Feral horse management in (4):392-396. Argentina: Two case studies of joint work. Second Latin­ Prishutova, Z.G. 2010. Feral horses (Equus caballus) as a com­ american National Parks and Protected Areas Congress. ponent of protected grassland ecosystems in the Rostovsky Bariloche, Argentina. Reserve. Russian Journal of Ecology 41:55-59. Scorolli, A.L., and A.C. Lopez Cazorla. 2010. Feral horse social Ransom, JI. 2012. Population ecology of feral horses in an era stability in Tornquist Park, Argentina. Mastozoologia Neo­ of fertility control management. Thesis, Colorado State tropical 17:391-396. University, Fort Collins, USA. Scorolli, A.L. 2012. Feral horse body condition: A useful tool Ransom, JI., B.S. Cade, and N.T. Hobbs. 2010. Influences of for population management? Presented at the International immunocontraception on time budgets, social behavior, Wild Equid Conference, 18-22 September 2012, Vienna, and body condition in feral horses. Applied Animal Behav­ Austria. iour Science 124:51-60. Slaukstins, V. 2002. The Lake Pape: Grazing of coastal grass­ Ransom, JI., N.T. Hobbs, and]. Bruemmer. 2013. Contracep­ lands. WWF Latvia project. Pages 197-207 in B. Redecker, tion can lead to trophic asynchrony between birth pulse P Finck, W. Hardtle, U. Riecken, and E. Schroeder (Eds), and resources. PLoS ONE 8:e54972. Pasture landscapes and nature conservation. Springer­ Ransom,J.I.,J.G. Powers, H.M. Garbe, M.O. Oehler Sr., TM. Verlag, Berlin, Germany. Nett, and D.L. Baker. 2014a. Behavior of feral horses in Southern States. 2013. Running wild-The feral ponies of Mount response to culling and GnRH immunocontraception. Ap­ Rogers, Virginia. Available at www.southernstates.com/ plied Animal Behaviour Science 157:81-92. articles I the-wild-ponies-of-mount-rogers-virginia.aspx Ransom, JI., JG. Powers, N.T. Hobbs, and D.L. Baker. 2014b. Spasskaya, N.N. 2008. Feral horses are not strangers in the Ecological feedbacks can reduce population -level efficacy steppe. [In Russian.] Steppe Bulletin 25:52-56. of wildlife fertility control. Journal of Applied Ecology Spasskaya, N.N. 2009. Steppe and horses: Conflict or coopera­ 51:259-269. tion? (Rostovsky Reserve). Reserve management: Problems Rewilding Europe. 2012. Wild horses released in Western in protection and ecological restoration of grassland Iberia rewilding area. Nijmegen, Netherlands. Available at ecosystems. Pages 130-134 in Proceedings of the interna­ http://rewildingeurope.com I news/ articles/ wild-horses­ tional scientific-practical conference dedicated to the 20th released-in-western -iberia-rewilding-area. anniversary of the organization of GPP "Orenburg." [In Rigueiro-Rodriguez, A., R. Mouhbi, J.J. Santiago-Freijanes, Russian.] Orenburg, Russia. M.D.P. Gonzalez-Hernandez, and M.R. Mosquera-Losada. Stanley, C.R., and S. Shultz. 2012. Mummy's boys: Sex dif­ 2012. Horse grazing systems: Understory biomass and plant ferential maternal-offspring bonds in semi-feral horses. biodiversity of a Pinus. Scientia Agricola 69:38-46. Behaviour 149:251-274. 148 History and Management

Stout, T.A.E., and B. Colenbrander. 2004. Suppressing repro­ Verderers of the New Forest. 2013. Available at www.verderers ductive activity in horses using GnRH vaccines, antagonists .org.uk. or agonists. Animal Reproduction Science 82-83:633-643. Vernes, K., M. Freeman, and B. Nesbitt. 2009. Estimating Tupac-Yupanqui, I., S. Dunner, B. Sanudo, A. Gonzalez, S. the density of free-ranging wild horses in rugged gorges Argtiello, et al. 2011. Genetic characterization of the caballo using a photographic mark-recapture technique. Wildlife breed and its relationships with other Spanish Research 36:361-367. local equine breeds [in Spanish]. Archivos de Zootecnia Vulink,J.T., M.R. van Eerden, and R.H. Drent. 2010. Abun­ 60:425-428. dance of migratory and wintering geese in relation to Turner,J.W, l.K.M. Liu, D.R. Flanagan, A.T. Rutberg, andj.F. vegetation succession in man-made wetlands regimes: The Kirkpatrick. 2001. Immunocontraception in feral horses: effects of grazing. Ardea 98:319-327. One inoculation provides one year of infertility. Journal of Walton, I. 2008. Mamiferos de Chile. Lynx Edicions, Barcelona, Wildlife Management 65:235-241. Spain. Turner, J. W, I. K. M. Liu, D.R. Flanagan, K. S. Bynum, and A. T. Warmuth, V., A. Eriksson, M.A. Bower,]. Canon, G. Cothran, Rutberg. 2002. Porcine zona pellucida (PZP) immunocon­ 0. Dist!, M.-L. Glowatzki-Mullis, H. Hunt, C. Luis, and traception of wild horses (Equus caballus) in Nevada: A 10 M. do Mar Oom. 2011. European domestic horses origi­ year study. Reproduction Supplement 60: 177-186. nated in two refugia. PLoS ONE 6:el8194. Tyler, SJ. 1972. The behaviour and social organization of Warmuth, V., A. Eriksson, M.A. Bower, G. Barker, E. Barrett, the New Forest ponies. Animal Behaviour Monographs et al. 2012. Reconstructing the origin and spread of horse 5:85-196. domestication in the . Proceedings of the UK Secretary of State. 2009. The horse passports regulations National Academy of Sciences of the USA 109:8202-8206. 2009. No. 1611. London, UK. Available at www.legislation Welsh Government. 2012. Equine identification and the semi­ .gov.uk/uksi/2009 / 161 l /contents/ made. feral ponies of Wales. Cardiff, Wales. Available at http:// US Congress. 1971. The Wild Free-Roaming Horses and Bur­ wales.gov. uk/ topics I environmentcountryside I ahw I ros Act, Public Law 92-195, 92nd Congress. horses I equineidsemiferalponies I ?Jang= en. US Congress. 2014. Wild Horse Oversight Act. ! 13th Congress. Winton, C.L., M.J. Hegarty, R. McMahon, G.T. Slavov, N.R. Valero, E.,J. Picas, F. Lago, and L. Lagos. 2013. Los acciden­ McEwan, M.C.G. Davies-Morel, C.M. Morgan, W Powell, tes de trafico relacionados con fauna salvaje en Galicia: and D.M. Nash. 2013. Genetic diversity and phylogenetic Incidencia, patron y soluciones. Presented at the 6th Con­ analysis of native mountain ponies of Britain and Ireland greso Foresta! Espanol, Vitoria, Spain. reveals a novel rare population. Ecology and Evolution van Dierendonck, M. 2012. Early reactive culling protocol in 3:934-947. the Oostvaardersplassen , the Netherlands. Zalba, S.M., and N.C. Cozzani. 2004. The impact of feral Presented at the International Wild Equid Conference, 18- horses on grassland bird communities in Argentina. Animal 22 September 2012, Vienna, Austria. Conservation 7:35-44. Vera, F. 2009. Large-scale nature development-The Oost­ vaardersplassen. British Wildlife 20:28-36. Contributors

Cheryl Asa, PhD Justine Chiu, BS St. Louis Zoo Princeton University USA USA

Shirli Bar-David, PhD E. Gus Cothran, PhD The Jacob Blaustein Institutes for Desert Research Texas A&M University Ben-Gurion University of the Negev USA Israel L. Stefan Ekernas, PhD Albano Beja-Pereira, PhD University of Montana Research Center in Biodiversity and Genetic USA Resources University of Porto Oyunsaikhan Ganbaatar, MS, PhD candidate Portugal Great Gobi B Strictly Protected Area Joel Berger, PhD Colorado State University Eva -Maria Geigl, PhD Wildlife Conservation Society Institut Jacques Monad USA Centre National de la Recherche Scientifique­ University Paris Diderot David Berman, PhD France Australian Wild Horse Management Services Australia Elena Giulotto, PhD Laboratory of Molecular and Cellular Biology Amos Bouskila, PhD University of Pavia The Jacob Blaustein Institutes for Desert Research Italy Ben-Gurion University of the Negev Israel Katherine A. Houpt, PhD Cornell University Lee Boyd, PhD USA Washburn University USA Halszka Hrabar, PhD Centre for African Conservation Ecology Qing Cao, MS, PhD candidate Nelson Mandela Metropolitan University Princeton University South Africa USA 220 Contributors

Petra Kaczensky; PhD Haniyeh Nowzari, PhD Research Institute for Wildlife Ecology Islamic Azad University University of Veterinary Medicine Vienna Iran Austria Cassandra M.V. Nunez, PhD Albert]. Kane, DVM, MPVM, PhD Iowa State University Animal and Plant Health Inspection Service USA US Department of Agriculture USA Sandra L. Olsen, PhD Division of Archaeology; Biodiversity Institute Fanuel Kebede, PhD University of Kansas Ethiopian Wildlife Conservation Authority USA Tsendsuren Oyunsuren, PhD Sarah R.B. King, PhD Institute of Biology Natural Resources Ecology Laboratory Mongolian Academy of Sciences Colorado State University Mongolia USA Jan Pluhacek, PhD Laura Lagos, PhD Institute of Animal Science Instituto de Investigaci6n y Analisis Alimentarios Czech Republic Universidad de Santiago de Compostela Spain David M. Powell, PhD Wildlife Conservation Society Nicolas Lescureux, PhD USA Centre d'Ecologie Fonctionnelle and Evolutive Centre National de la Recherche Scientifique Melanie Pruvost, PhD France Institut Jacques Monod Centre National de la Recherche Scientifique­ John D.C. Linnell, PhD University Paris Diderot Norwegian Institute for Nature Research France Norway Jason I. Ransom, PhD Victor Lukarevskiy, PhD Natural Resources Ecology Laboratory Russian Academy of Science Colorado State University Russia USA

Patricia D. Moehlman, PhD Daniel I. Rubenstein, PhD IUCN I SCC Equid Specialist Group Chair Princeton University Tanzania USA

Dejid Nandintsetseg, MS, PhD candidate Kathryn A. Schoenecker, PhD Senckenberg Biodiversity and Climate Research US Geological Survey Centre Natural Resources Ecology Lab Goethe University Colorado State University Germany USA

Megan K. Nordquist, MS Mandi Wilder Schook, PhD Brigham Young University Cleveland Metroparks Zoo USA USA Contributors 221

Alberto Scorolli, PhD Universidad Nacional de! Sur Argentina

Natalia N. Spasskaya, PhD Zoological Museum of Moscow Lomonosow State University Russia

Dorj Usukhjargal, MS, PhD candidate Hustai National Park Mongolia

Waltraut Zimmermann, PhD Przewalski's Horse International Studbook Keeper Equid Taxon Advisory Group European Association of and Aquariums Germany