The spatial patterns of indigenous wildlife use in western Panama: Implications for conservation management

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The spatial patterns of indigenous wildlife use in western Panama: Implications for conservation management Derek A. Smith* Department of Geography and Environmental Studies, Carleton University, Ottawa, Ontario, Canada K1S 5B6

A R T I C L E I N F O

A B S T R A C T

Article history:

Measuring the impacts of indigenous hunting on neotropical wildlife populations remains

Received 25 April 2007

a difficult task. Significant insights can be gained by analyzing the spatial patterns of hunt-

Received in revised form

ing yields. This paper presents a geographic analysis of game captured by hunters in 59

11 December 2007

households belonging to five neighbouring villages in western Panama over a period of

Accepted 30 December 2007

232 days. The locations of 1269 game kill sites within a hunting zone of 131 km2 were documented with trained local investigators and then entered into a geographic information system with associated attribute data for analysis. Results show a heavy concentration

Keywords:

of kill sites around the study communities. Nearly 90% of the total harvest by weight

Wildlife management

was captured within just 2 km of hunters’ homes. Yet, while several species are captured

Hunting

in large numbers close to home, others are caught closer to the outer peripheries of the

Indigenous peoples

shared hunting zone, suggesting that some degree of localized depletion may have

Tropical forests

occurred. The findings demonstrate the value of mapping the boundaries of hunting zones

Panama

and game kill sites to assess the impacts of hunting on game species in tropical and other ecosystems and to provide an empirical basis for delimiting conservation zones that balance the use and protection of wildlife in tropical forest regions. Ó 2008 Elsevier Ltd. All rights reserved.

1. Introduction: indigenous wildlife conservation

peoples

and

Indigenous peoples in the humid neotropics continue to rely heavily on subsistence hunting, although the type and quantity of game harvested varies considerably in relation to numerous cultural, economic, technological and ecological factors (Bergman, 1980; Berlin and Berlin, 1983; Bodmer, 1995; Gavin, 2007; Grenand, 1992; Hames, 1979; Jerozolimski and Peres, 2003; Peres and Nascimento, 2006; Posey, 1985; Stearman, 1995; Ventocilla, 1992; Vickers, 1991; Yost and Kelley, 1983). Hunting also plays a vital role in indigenous cultural identities, which is reflected in the prominence of game animals in indigenous cosmologies, arts, legends, cal˚ rhem, 1996; Bale´e, 1985; Descola, 1994; endars and rituals (A Johnson, 1989; Reichel-Dolmatoff, 1996; Reina and Kensinger,

1991; Rival, 1996). At the same time, tropical rain forests have become a primary focus of international conservation efforts, and indigenous peoples living in these regions have found themselves at the center of a debate about how these environments should be used and managed (Alcorn, 1993; Herlihy, 1997; Peres and Zimmerman, 2001; Redford, 1990; Schwartzman and Zimmerman, 2005; Terborgh, 2000). Finding an appropriate balance between the use and conservation of game species is of interest to all concerned, but finding that balance is not an easy task. The biological data needed to make sound assessments is often in short supply, and the direct and indirect impacts of hunting on game populations vary considerably from place to place (Milner-Gulland and Akc¸akaya, 2001). While it is widely accepted that indigenous forms of forest use are more sustainable than those of most other groups, growing population pressure, changes in belief

* Tel.: +1 613 520 2600x8131. E-mail address: [email protected]. 0006-3207/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.biocon.2007.12.021

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systems, and increased participation in market economies are placing greater pressure on vulnerable wildlife species (Godoy et al., 1995; McSweeney, 2005; Stearman, 1992, 1995). Notwithstanding the uncertainties surrounding the impacts of indigenous hunting on neotropical wildlife populations, studies have provided evidence of game depletion of some – but certainly not all – species, as indicated by declining yields over time, the need to travel farther to find game, or lower game densities in hunted versus similar, unhunted areas (Carrillo et al., 2000; Hill et al., 1997; Hill and Padwe, 2000; Mena et al., 2000; Mittermeier, 1991; Naranjo and Bodmer, 2007; Orejuela, 1992; Peres, 1990, 1991, 2000a,b; Stearman, 1995; Thiollay, 2005; Vickers, 1980, 1991). Researchers have also attempted to measure the sustainability of hunting by comparing harvest rates with estimates of maximum reproductive rates (Alvard et al., 1997; Bodmer et al., 1994; Hurtado-Gonzales and Bodmer, 2004; Leeuwenberg and Robinson, 2000; Mena et al., 2000; Robinson and Bennett, 2000, 2004; Robinson and Redford, 1991; Townsend, 2000). One of the limitations of the models currently in use, however, is that they do not adequately take into account how hunting activity and game abundance vary across space (Milner-Gulland and Akc¸akaya, 2001; Sire´n et al., 2004). Documenting the spatial dimensions of hunting can help to better understand its impact on game populations, as well as the development of better conservation strategies that rely on zones with different types or levels of use (Robinson and Bennett, 2004; see also Herlihy, 1999; McCullough, 1996). This paper presents a geographic analysis of indigenous wildlife use in western Panama, focusing on the distribution of over 1250 game kill sites in relation to human settlement patterns. A central objective of the research was to see if there are significant differences in the spatial distribution of kill sites for different species and assess whether these patterns indicate that certain species have been overhunted, resulting in game depletion. A primary hypothesis was that while some species are more resilient, other species that are more vulnerable to hunting pressure would be caught primarily on the peripheries of subsistence lands, which would be evident in an absence of kill sites near indigenous villages. The spatial patterns of hunting in relation to different hunting strategies and habitats are also discussed.

2.

The geography of hunting

The spatial dimensions of hunting are an important consideration in attempts to understand the impacts of indigenous hunting for a variety of reasons. At the most basic level, knowing the boundaries of hunting zones provides an accurate estimate of their size, which is a key variable in models attempting to measure the sustainability of hunting based on calculations of maximum sustainable offtakes per unit area (Robinson and Bennett, 2004). There are a few studies that have attempted to accurately delimit the boundaries of the lands used by indigenous hunters in the neotropics (Dunn, 2004; Herlihy, 2003; Herlihy and Leake, 1997; Leeuwenberg and Robinson, 2000; Mena et al., 2000; Vickers, 1991). However, amidst the large literature on indigenous hunting (conducted mainly by anthropologists and conservation biologists), these studies are rare, and there remains much to

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learn about the shape and size of hunting zones and how they are conditioned by population size, topography, habitat, and the proximity and location of neighbouring settlements. Documenting the shape and size of hunting zones can also help identify areas that are free of hunting pressure, which can serve as source areas to help repopulate hunting grounds through the migration of individuals from areas that are near or at carrying capacity (Escamilla et al., 2000; Naranjo and Bodmer, 2007; Novaro et al., 2000; Peres and Nascimento, 2006). Identifying these areas can also be used to delimit conservation zones that recognize the realities of local wildlife use. As indigenous populations grow, it will be increasingly important to identify and establish protection for these core areas in collaboration with local communities. Another geographic parameter of hunting discussed here is the spatial distribution of wildlife use within hunting zones. Environmental conditions, of course, are not uniform within these areas, but vary across space and over time. The distribution of different microclimatic environments, soils, hydrological conditions, tree-fall gaps, anthropogenic disturbances, and the seasonal variation in leaf growth, fruiting, and flowering of different plant species in response to biotic and abiotic factors produce ecological landscapes that are far from homogenous (Collinge, 2001; Eisenberg and Thorington, 1973; Foster, 1980; van Shaik et al., 1993; Tilman and Kareiva, 1997). The distribution and abundance of game species is tied to the resulting irregular distribution of available resources through processes such as dietary switching, seasonal breeding, change in the use of ranges, and migration (Peres, 1994; van Shaik et al., 1993). Not surprisingly, hunting effort and hunting yields also vary across space (Bale´e and Ge´ly, 1989; Bodmer, 1995; Nietschmann, 1972; Peres, 1994; van Shaik et al., 1993). A number of studies have documented different aspects of the spatial patterns of indigenous wildlife use within hunted areas. One early study in Venezuela showed how overall hunting efficiency was significantly greater in more distant areas, how larger quantities of game are captured with increased distance from the village, and how hunters rotate hunting sub-zones in response to game depletion to allow for replenishment, in a manner analogous to shifting cultivation (Hames, 1980). Vickers (1991) divides a Siona-Secoya hunting area into four major sub-zones based on frequency of use, noting that while a curassow species (Mitu salvini) had been depleted within the nearby, core area, most species have been harvested at sustainable rates. Mena et al. (2000) similarly divide a Huarorani hunting zone into persistently hunted area and an infrequently hunted area. Another study in eastern Paraguay shows that the probability of encountering signs of indigenous hunters declines with distance, and is close to zero beyond 10 km (Hill et al., 1997). In central Brazil, it appears that Waimiri Atroari hunters are more successful in more distant hunting areas compared to sites close to home (Remor de Souza-Mazurek et al., 2000). Together, these studies suggest a general pattern of localized depletion of game near human settlements, associated with higher levels of hunting effort close to home (Sire´n et al., 2004). However, while valuable, most studies that pay attention to the spatial patterns of hunting rely on indirect measures of localized game depletion or use large, general divisions within hunting

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zones for their analysis, rather than the locations of individual kill sites (for a notable exception outside the tropics see Calvert et al., 2005). The research presented below attempts to provide new insights into these issues through participatory mapping of game kill sites in western Panama.

3.

Study area and research methodology

The study area includes five neighboring communities in the Rı´o Caloveborita watershed of western Panama that share a common hunting zone with little overlap with areas used by other communities (Fig. 1). The participating communities are typical of hundreds of indigenous settlements in the humid neotropics: overall population density is relatively low, and residents are heavily reliant on natural resources to meet their basic needs. They live in close proximity to extensive

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areas of mature forest that are an important source of game. The area does not fall within any protected area except for a small part of the hunting zone which is found within the northwest corner of the 726 km2 Parque Nacional Santa Fe, established in 2001. The combined population of the five communities in 1999 was 725, including indigenous Bugle´ and Ngo¨be families, as well as Spanish-speaking Mestizos (born in the region, not recent colonists) and people of mixed descent. Shifting cultivation is the primary subsistence activity, complemented by animal husbandry, hunting, fishing, and the gathering of wild plant foods. Each household typically has 2–3 small active gardens, and fallow periods vary considerably, ranging from 2 to 3 to over 20 years. The region is one of the more remote parts of Panama and there is limited involvement in outside markets, although the majority of adult men leave the region

Fig. 1 – Map of study area showing house sites and hunting zone of five neighbouring, Caloveborita region, 1999–2000.

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to work on sugar plantations in other parts of the country for one to several weeks during the harvest season. Hunting strategies are varied, including individual and group hunting trips, waiting for game in fixed locations, the use of a variety of traps, and unplanned, opportunistic hunting that occurs when people are engaged in some other activity (Smith, 2005). The main weapons are rifles and shotguns, the bow and arrow, and slingshots. Dogs are also used, especially for capturing rodents and other terrestrial mammals. Men catch most game but women, who tend to rely more heavily on traps, captured 6% of the overall harvest and make important contributions to the game harvest of certain households (Smith, 2005). Hunting is practiced almost exclusively to obtain meat, although certain animal parts are used occasionally for other purposes (e.g., adornment, musical instruments, bone tools). Of a total of 99 households in the study area, 59 participated in the research which was endorsed by local and regional indigenous leaders after a series of consultations (Smith, 2003). This included 82 people who captured at least 5 kg of game over the eight month study period, as well as all other members of these households, including women and children. The 40 remaining households were removed from the study based on a preliminary survey showing that their reliance on hunting is limited or negligible. Questionnaires were administered by 10 trained local investigators among households in their respective communities every week, covering a period of 232 days, from October 1999 to June 2000 (although at times when local investigators were unavailable, I administered the questionnaires myself). As per customary practice, the local investigators were chosen by indigenous authorities, guided by prerequisites that I established. All are hunters themselves who are longstanding, well-respected members of their respective communities and are fluent in the languages used in their communities. While most have only a few years of formal schooling, all have extensive empirical knowledge of local subsistence practices and wildlife ecology (Smith, 2003). Three group training sessions were held over a total of five days early in the field research, and careful review of the work of local investigators and subsequent individual training was provided as needed on an ongoing basis to ensure accuracy and reliability of the questionnaire results. The questionnaires collected information related to all game animals captured by household members, including the age and gender of the hunter, the weapon and strategy used; the time of day and date captured; the sex of the animal and whether it was an adult or juvenile; and the type of habitat in which it was encountered – either mature forest, tall fallow, young fallow, or an active garden. In this region it is relatively easy to identify mature forest based on distinctive floristic characteristics (e.g., thick vines), but also because when people began establishing new farms in the area about 100 years ago, the forests they encountered had not been cleared for centuries. When administering the questionnaires, local investigators drew sketch maps on blank sheets, showing the location of kill sites (excluding small birds and other minor species mainly <100 g) in relation to streams, houses, trails, and other features. These locations were later plotted onto 1:50,000 topographic base maps during meetings between myself and each local investigator that occurred

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about every two weeks throughout the research period. The local investigators, because they are hunters themselves with intimate knowledge of the area, could easily understand the locations of game kill sites when applying the questionnaires, and then place them on their sketch maps. Together we worked patiently and carefully to accurately transfer these locations onto the base maps. This was greatly facilitated by the fact that the region is heavily dissected, with an extensive network of named streams, as well as my own knowledge of the region gained from accompanying people on outings while residing in the region for four months before mapping game kill sites began (Smith, 2003). As such, it was possible to plot these sites with an accuracy of roughly 50–200 m for the vast majority of kill sites, something that was corroborated through hunting trips that I participated in, when locations were recorded separately with the help of a global positioning system receiver. No information was collected on animals that were wounded but which escaped. A few game kill sites could not be plotted with complete confidence, so were excluded from the spatial analysis, but these make up less than 1% of the total harvest. During field work, I also conducted a variety of formal and informal interviews; carried out field mapping of land cover and settlement; and accompanied residents on 20 hunting expeditions, including two multiple-day trips. Data on fishing activity was also collected, but are not presented here. Hunting activity questionnaire data were entered into spreadsheets, together with weights for each game animal captured, using body mass estimates from published sources (Dunning, 1993; Eisenberg, 1981; Robinson and Redford, 1986; Stiles and Skutch, 1989), distinguishing between sexes where appropriate. Juveniles were simply assigned half of adult weights. Kill sites and all associated attribute data were entered into a geographic information system (GIS) database using ArcGIS software (version 9.1). An overlay analysis was used to calculate the amount of game captured within 500m distance intervals around hunters’ homes. Their primary residences were chosen rather than village centers so as to create buffer areas that better reflect the dispersed nature of settlement in the region. The boundaries of mature forest were also digitized, based on field mapping data, and all primary and secondary house sites were likewise entered into the GIS database, linked to attribute information obtained from a complete census of the study area conducted in the field. The boundaries of the hunting zone were delimited based on the distribution of game kill sites, along with my own observations and interviews that occurred while accompanying hunters throughout the field research, including the reconstruction of the route of hunting expeditions in which I participated. The ArcGIS software was used to calculate spatial statistics and conduct average nearest neighbour analysis of game kill sites.

4.

Results

4.1.

The hunting zone

The lands used for hunting by the Bugle´, Ngo¨be, and nonindigenous villagers living in the five study communities have a total area of 131 km2, with an estimate of 80.5 km2 of forest

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and 50.7 km2 of agricultural lands, the latter consisting of habitat mosaics containing village lands, active farms, young fallows in various stages of succession, secondary forests, small pastures, and fragments of mature forest (mainly 2– 5 ha in size) (Fig. 1). The most distant areas used by hunters are about 7 km from village centers. It should be noted, however, that the limits of hunting are diffuse and dynamic, and the delimitation presented here is an estimation of all areas used by hunters at the time of field research. Within this hunting zone, 2580 kg of game were caught (including game animals captured during the first two weeks of data collection whose kill sites were not mapped), or an average of 43.7 kg per household over eight months. While agricultural lands cover only 39% of the hunting zone, 47% (1213 kg) of all game caught by weight was obtained from these areas, which is in keeping with other studies that have documented the contribution of human-modified, anthropogenic habitats to total hunting yields (Bale´e, 1985; Dunn, 2004; Grenand, 1992; Smith, 2005). While the limits of unhunted areas were not mapped systematically, the location of settlements outside of the

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study area, interviews, and other anecdotal evidence shows that there are large areas of contiguous, undisturbed forest to the east and southeast of the hunting zone that are not used by hunters at all, or at most, only very rarely.

4.2.

The distribution of game kill sites

A total of 1269 game kill sites were documented, representing 96% of all game captured during the study period by weight (as noted above, the kill sites of numerous small game species were not mapped) (Fig. 2). The most striking general pattern is a heavy concentration of kill sites around the five villages. This is apparent upon visual interpretation of the map of kill sites and is confirmed by an average nearest neighbour analysis which indicates that the kill sites are highly clustered (z-score 31.3, p = 0.01) around the mean centre, or average location of the kill sites. The standard distance of kill sites locations (the spatial equivalent of the standard deviation) from the mean centre, both weighted by body mass of the game animals captured, is 3.6 km (Fig. 2). The clustering of kill

Fig. 2 – Map showing locations of game kill sites, Caloveborita region, 1999–2000 (n = 1269, 232 days).

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sites around the villages is due in part to the fact that 20% of the harvest consisted of game caught opportunistically during various daily activities that take place near the home. Many of these are small animals such as basilisk lizards, squirrels, and pigeons that make minor contributions to the total harvest. Another 13% of all game was harvested while waiting at specific sites where animals have been foraging, which takes place almost exclusively in cultivated fields surrounding the villages. Traps likewise tend to be placed near villages where they can be more easily monitored. Nevertheless, even if we focus only on game caught during hunting trips, the concentration around human settlement continues to be evident (Fig. 2). Most of the kill sites located in more distant forest areas represent animals caught using a firearm, which is consistent with the statements of local residents who explain that they are much less inclined to undertake hunting trips if they do not have access to a rifle or shotgun. Not having access to a firearm, in fact, was the most common explanation provided by people for why they do not hunt. The prevalence of kill sites around the five communities can also be explained in large part by the fact that many of the species captured in large numbers – including collared peccaries (Tayassu tajacu), armadillos (Dasyprocta punctata), pacas (Agouti paca), rabbits (Sylvilagus brasiliensis) and chachalacas (Ortalis cinereiceps) – are attracted to gardens and fallows as productive foraging areas, or for shelter or cover (Smith, 2005). The concentration of game captured near the villages is also augmented by the characteristics and distinct ways in which some species are encountered. The oligno (Bassaricyon gabbii), for example, is a nocturnal, mature forest species that is normally found in the upper canopy where it is difficult to observe. Indigenous hunters capture this animal almost exclusively when clearing large trees for new farms at the edge of the forest, which in the Caloveborita region is usually within 2–3 km from where they live. The concentration of kill sites in the central part of the hunting zone is also observable at the community and household levels. Although a significant amount of overlap occurs between the zones where each community caught game during the study period, there is a strong concentration of kill sites around each settlement (Fig. 3). One exception to this general pattern is a separate cluster of game caught by Quebrada Larga residents in the upper Rı´o Palmar watershed around a secondary house site used periodically by two families from Quebrada Larga. Another is apparent around the hamlets of Quebrada Tuza and Quebrada Larga Arriba (considered part of the village of Caloveborita) where there is a paucity of kill sites. Much less hunting takes place in the households of these two sites, which is likely related to lower game abundance and thus lower hunting efficiency, as well as ethnicity – all of the families here are Mestizo, and hunting does not seem to play as important a role in their way of life. Mestizo hunters that were included in the study captured an average of 1.3 kg of game per month, compared to an average of 4.0 kg/month among indigenous hunters. Some linear patterns along forest trails are also apparent in the distribution of kill sites. The most obvious is a series of kill sites along a trail that crosses over a ridge to the Rı´o Gua´zaro watershed to a rudimentary hunting shelter in the

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eastern part of the hunting zone, around which a separate, isolated cluster of kill sites is found (Fig. 2). Other examples along trails used for shorter outings are also evident at scales showing smaller areas. It is worth noting, however, that trails are abandoned and new ones created on a regular basis and that hunters move off trails when following animal signs, crossing over to another trail, or taking a more direct route home. As such, the areas used most intensively by hunters in the Caloveborita region are continually shifting with the establishment and decline of different hunting trails, but virtually every part of the hunting zone is used during any given year, even if only rarely. Figs. 1 and 2 provide a good indication of where animals are being caught, but do not show important variations between species. While some animals are caught close to home others are not. Primates are more vulnerable to forest clearance and hunting pressure and are typically among the first species to be depleted in areas where they are hunted (Bodmer et al., 1997; Hill et al., 1997; Orejuela, 1992; Stearman, 1995; Vickers, 1991). If this were the case in the Caloveborita region, where hunting has occurred regularly for at least 50 years, one would expect the depletion of these species to be evident in the distribution of kill sites. The locations of primate kill sites do give some indication that this is indeed the case as most were encountered toward the outer limits of the hunting zone (Fig. 4). However, both howler monkeys (Alouatta palliata, total of 33 captured) and capuchin monkeys (Cebus capucinus, 13 captured) continue to be encountered relatively close to the study villages. Many were captured within only 2 km of hunters’ homes, suggesting that depletion has been limited (Table 1). In contrast, the four spider monkeys (Ateles geoffroyi) that were caught during the study period were all encountered close to the southeastern periphery of the hunting zone (during a single expedition), an indication that this species has been overhunted and may require special protection. While this is a relatively small number of individuals upon which to base conclusions, and may also be related to habitat preferences or increased wariness rather than game depletion, the absence of spider monkey kill sites throughout most of the mature forest areas within the hunting zone remains noteworthy. Other species that are among those most commonly reported as having been depleted by subsistence hunters elsewhere in the humid neotropics are cracids, tinamous, and other large birds (Peres, 2000b; Silva and Strahl, 1991; Vickers, 1991). However, the large game birds that one would expect to be most vulnerable to overhunting, namely the great curassow (Crax rubra), the crested guan (Penelope purpurascens), and the great tinamou (Tinamus major), do not show much evidence of game depletion in the Caloveborita region, at least not based on the spatial distribution of kill sites (Fig. 4). Again, all three species are caught within easy reach (i.e., within 2– 3 km) of human settlement (Table 1). The apparent difference between the spider monkey and other mature forest species is not entirely clear. Given that all are captured primarily or exclusively in mature forest, it appears that other factors are more important – for example, detectability and ease of capture or differential reproductive rates. All are highly preferred species that will be pursued by hunters whenever they are encountered.

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Fig. 3 – Map of game kill sites classified by community, Caloveborita region, 1999–2000 (n = 1269, 232 days).

The spatial distributions for other taxa display their own unique patterns. Brocket deer (Mazama americana), collared peccaries, and agoutis (Dasyprocta punctata) are larger animals that tend to be caught close to villages (Table 1). The red tailed squirrel (Sciurus granatensis) is also caught close to human settlement, mainly within 1 or 2 km of village centers. Kill sites are especially numerous along trails that run alongside rivers where large forest trees that provide favoured foods have been protected. Basilisk lizard kill sites are captured exclusively along streams, not surprising given its semi-aquatic nature and the fact that it is often captured by boys with slingshots who spend a lot of their free time near rivers close to home. The findings show that there are indeed significant differences in the distribution of game kill sites of different species. The differences are most evident when comparing the kill

sites of ‘‘garden game’’ species that are caught frequently in agricultural areas close to home and the ‘‘deep forest game’’ species that are caught farther from home (Smith, 2005). Also notable is the lack of white-lipped peccary (T. tajacu) kills. While local hunters affirm that herds of this species pass through the region from time to time, its presence is sporadic and apparently less and less frequent, suggesting that it may have suffered population declines. Similarly, only one tapir (Tapirus bairdii) was captured during the study period (although tracks of at least two others were encountered), which again suggests that it has been depleted in the region.

4.3.

Hunting yields as a function of distance

A more systematic analysis of how hunting yields are conditioned by distance from human settlement was undertaken

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Fig. 4 – Map of kill sites highlighting locations for primates and large birds, Caloveborita region, 1999–2000 (n = 1269, 232 days).

by taking into account both the location of kill sites as well as weight of each animal captured. The total amount of game within distance intervals of 500 m was calculated, showing that the amount of game caught sharply declines as one moves farther away from the study area communities (Fig. 5). Remarkably, 73.8% of all game by weight was caught within only 1 km of a hunter’s house, and 89.0% of all game was captured within just 2 km (Table 2). The pattern is even more pronounced when looking at the numbers of animals captured within different distance intervals, with 94.4% of all individual kill sites mapped occurring within 2 km of hunters’ homes. But again, this includes numerous small animals that do not make significant contributions to the total harvest by weight. The average body mass of game increases with dis-

tance, from 1.7 kg within 1 km of hunters’ homes, to an average of 3.8 kg for animals captured at distances of more than 3 km (Table 2). On a per unit area basis, the hunting grounds within 1 km of hunters’ residences provided the most game over the eight month period, at 39.1 kg/km2, compared to the overall rate of 17.6 kg/km2 (Table 2). Even when only considering game caught during hunting trips, the trend remains the same. An estimated 59% of all game captured during hunting trips was caught within just 1 km of a hunter’s house, and 80% was caught within 2 km (Fig. 5). The results demonstrate that Bugle´ and Ngo¨be hunters in the Caloveborita region do not need to travel far to find game, and that except for particularly sensitive species their impact on game populations in distant forest areas appears to be slight, even

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Table 1 – Number of animals captured within different distance intervals for taxa with >3 individuals captured and a total harvest P5 kg, Caloveborita region, 1999–2000 (232 days) Total harvest Total number Percentage of individuals captured within different distance intervals (km) (kg) captured 0–1 1–2 2–3 3–4 4–5 5–6 6–7 Bassaricyon gabbii Echimyidae Nasua narica Sylvilagus brasiliensis Ortalis cinereiceps Tayassu tajacu Pteroglossus torquatus Agouti paca Basiliscus plumifrons Columba spp. Dasypus novemcinctus Sciurus granatensis Potos flavus Bradypus variegatus Tinamus major Choloepus hoffmanni Mazama americana Ramphastos swainsonii Ramphastos sulfuratus Dasyprocta punctata Rhinoclemys annulata Crax rubra Penelope purpurascens Cebus capucinus Alouatta palliata Ateles geoffroyi

8.4 7.3 25.2 23.4 5.9 149 16.5 292 21.3 8.5 275 62.5 46.1 110 31.0 108 104 19.9 6.9 292 47.2 47.7 25.8 39.0 188 30.0

4 17 9 29 15 14 77 46 88 44 99 184 21 36 33 16 4 32 21 101 42 14 15 13 33 4

100 100 100 100 93 93 92 91 91 89 88 86 81 81 76 75 75 72 71 64 55 36 33 31 3 –

– – – –

– – – – – – – – – – –

7 7 8 9 8 11 12 11 19 14 18 13 – 22 29 33 33 57 13 15 33 –

– – – – – – – –

– – – – – – – – – – – – – – – – – – – – – – – – – –

1 – – 2

1

–

– 3

3

–

–

6 25 3 – 3 10 7 27 15 33 –

6 – 3 – 2 – 7 15 6 100

– – – – – – – – – – – – – –

– – – – – – – – – – – – – – 3

– – – – – – – 7 23 18 –

3 – – – – – – – 13 – 6 –

900 800

Game harvest (kg)

700 600

All other strategies

500

Hunting trips

400 300 200 100

-7 .0 6.5

-6 .5 6.0

-5 .5

-5 .0

-4 .5

-6 .0 5.5

5.0

4.5

4.0

-4 .0 3.5

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-2 .5 2.0

-1 .5

-1 .0

-2 .0 1.5

1.0

0.5

0-

0.5

0

Distance from village (km)

Fig. 5 – Hunting yields as a function of distance from hunters’ primary residences, 500-m intervals, Caloveborita region, 1999–2000 (232 days).

though the total area used is fairly large and the total amount of game captured is significant.

5.

Discussion and concluding remarks

The spatial patterns of wildlife use hold revealing clues about the relationships between indigenous communities and neo-

tropical game populations, and represent a useful parameter in the assessment of the sustainability of hunting activity, along with other measures such as the evaluation of harvest rates in relation to maximum sustainable yields or the analysis of the catch per unit effort (Bodmer and Robinson, 2005; Puertas and Bodmer, 2005; Remor de Souza-Mazurek et al., 2000; Sire´n et al., 2004). The type and quantity of game

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Table 2 – Variation in the number of animals captured, average body mass, and yields per unit area for primary game species captured at varying distances from hunters’ primary residences, Caloveborita region, 1999–2000 (232 days) All game

Number of animals captured Amount of game captured by weight (kg) Average body mass of animals captured (kg) Yield per unit area within limits of hunting zone (kg/km2)

1269 2304 1.82 17.6

Game yields within different distance intervals (km) 0–1

1–2

2–3

3–4

4–5

5–6

6–7

1001 1700 1.70 39.1

197 350 1.77 10.1

38 129 3.39 5.4

17 63.4 3.73 3.8

1 1.0 1.00 0.2

10 44.2 4.42 12.6

5 17.0 3.40 11.3

Note: Does not include numerous small game species whose kill sites were not mapped and that make up 4% of the harvest by weight during the data collection period.

captured across space varies in relation to numerous human and ecological variables including human settlement patterns, the use of different technologies, gender, cultural preferences, transportation routes, and the varying abundance of game, which is in turn affected by environmental factors as well as the creation of heterogeneous landscapes through shifting cultivation and the history of hunting in a particular area. This study provides an accurate delimitation of an indigenous hunting zone by mapping game kill sites combined with other methods, providing a precise estimation of the size of the area used by hunters. The pattern of game kill sites shows that in the Caloveborita region, the capture of game animals is heavily concentrated around human settlement. This is due in large part to the importance of opportunistic hunting, waiting for game at fixed locations, and the use of traps, all of which tend to occur in garden areas close to the home. On average, men only go on hunting trips to the more distant forest areas only a few times per month. In addition, while most hunting trips are directed towards forest areas, hunters pass through agricultural lands every time they embark on an expedition, and some of the game caught during these trips occurs in nearby anthropogenic habitats. As such, hunting pressure declines steadily with distance – something that is reflected in the overall distribution of kill sites. The findings presented here demonstrate that hunting pressure in mature forest – particularly in relatively distant forest areas – may be less significant in many neotropical rain forest regions due to the presence of game in gardens and fallows found near indigenous settlements. When significant amounts of game can be harvested from nearby agricultural and transitional ecotone areas, much less hunting pressure may be placed on species in the forest, particularly when time is limited due to the demands of other economic activities (e.g., clearing fields, weeding, wage labour). Even the most active hunters travel to distant forest areas only occasionally, and obtain most of their wild meat close to home during short hunting trips, using traps, or while waiting for game animals that have been raiding crops. So, although the total area used by indigenous hunters is significant, much of it is used only lightly. As a result game kill sites are concentrated around where people live, and the amount of game caught by weight sharply declines with increases in distance from human settlement. The friction of distance is thus a key variable affecting wildlife use in the Caloveborita region. However, there is also evidence that at least one species, the spider monkey (A. geoffroyi), has been depleted by hunters – only four were

captured, all, near the outer boundaries of the hunting zone adjacent to unhunted source areas. Documenting game kill sites along with other harvest data can provide valuable evidence about whether levels of hunting are sustainable or not, and provide practical information for wildlife conservation management. An awareness of which species are frequently captured close to home in conjunction with other methods that assess the sustainability of hunting and status of wildlife species can help conservationists avoid regulating species that are not endangered in a particular locale. Few wildlife measures are more frustrating for local people – thereby jeopardizing broader conservation initiatives – than efforts to protect species that are significant agricultural pests. However, it is important to interpret the spatial patterns of game kill sites carefully, taking into account the possibility that an abundance of kill sites close to home may reflect a surge in hunting effort rather than sustainable use – just as the capture of only a few individuals may reflect a depleted population rather than sustainable hunting rates. An understanding of the spatial patterns of wildlife use can also help develop appropriate boundaries of conservation zones with different levels of use and protection – a strategy analogous to the delimitation of different zones within biosphere reserves, but on a much smaller scale. While it is true that hunting patterns change over time and that fixed boundaries might be problematic, if zones with different levels or types of use are established with local participation, they will stand a much better chance of being recognized and respected over the long term, as opposed to protected areas that are imposed from outside and conflict with local land use practices. The Bugle´ and Ngo¨be are in fact concerned about maintaining game populations over the long run and have discussed different conservation measures during local and regional assemblies. Using participatory methodologies to map game kill sites and the boundaries of hunting zones at a regional scale can help identify source areas that may serve to repopulate the sinks surrounding indigenous settlements – and which could be converted from de facto conservation areas to more formally protected reserves recognized by local communities. Maps already play prevalent and critical roles in efforts to protect wildlife species and their natural habitats. Better spatial data on hunting activity can help produce better cartographic information and help to design more effective conservation initiatives.

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Acknowledgements I would like to express my deep gratitude to residents in the Caloveborita region for supporting the research, for their patient cooperation in the administration of questionnaires, and for sharing their knowledge during interviews. I would also like to thank the local investigators who participated in the data collection for their dedicated work, especially Antonio Virola Almanza who provided particularly valuable support. Drs. Kendra McSweeney and Scott Mitchell and three anonymous reviewers kindly reviewed earlier drafts of this manuscript and provided insightful suggestions. The National Science Foundation (Doctoral Dissertation Improvement Grant, NSF, 19540/990818), the Chicago Zoological Society (Conservation and Research Grant), the Tinker Foundation (Tinker Foundation Field Research Grant), and the Pierre Stousse Memorial Fund, University of Kansas, provided generous financial support for the research.

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