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1
Distribution of Mantled Howler monkeys (Alouatta palliata) in
Bella Vista and Limones, Chiriquí, Panama
Emma Sutherland and Tara Jagadeesh
Host
information:
Universidad
Autónoma de
Chiriquí
Address:
Host contact: Dr. Ariel Rodríguez-Vargas
Phone: (507) 730 - 5300
Email: ariel.rodriguez@unachi.ac.pa
April 2017
Hours spent in the field: 104 hours
Hours spent working in Panama: 50 hours
Hours spent traveling: 120 hours
Total: 270 hours
Table of Contents
2
I. Introduction 3
Background 3
Area of study 4
II. Methods 5
Data collection 7
Data analysis 9
III. Results and discussion 6
Biological data 10
1. Distributions and density 10
2. Demography 12
3. Behavior 13
Social data 14
1. Perceived threats 14
2. General observations 15
3. Future conservation ventures 16
IV. Conclusion 20
V. Works Cited 23
VI. Figures and tables 26
VII. Appendices 33
Introduction
3
Background
The Mantled Howler Monkey (Alouatta palliata) is part of the New World monkey
family Atelidae and is one of six species of monkeys found in Panama. Its distribution ranges
from eastern Mexico to the Pacific coasts of Colombia and Ecuador (Mann 2005). Howler
monkeys are an arboreal, diurnal species. Of all of the Howler monkey species, A. palliata
consistently lives in the largest groups, with ≥10 individuals (Chapman and Balcomb 1998).
They are frugivores, usually eating young leaves but preferring mature fruits when they are
available (Estrada 1984). They are found in a wide range of habitats but prefer evergreen and
semi-evergreen forest due to consistent food production throughout the year (Chapman &
Balcomb 1997). Although they prefer these forests, the most important indicator for selection of
habitat by howlers is density of tree cover (Stoner 1996). This is important in the context of
deforestation, which increasingly poses a threat to species worldwide. However, howlers have
been shown to adapt to changing environments (Clarke et al. 2001), and can alter their diet
depending on food availability in the area (Christóbal-Azkarate & Arroyo-Rodríguez 2007). This
flexibility allows howler monkeys to more readily persist in regions affected by anthropogenic
disturbance in comparison to other, more sensitive species.
Despite their flexibility in habitat selection, these monkeys face a variety of threats.
Deforestation is occurring in Panama at a rate of 0.71% (27,050 hectares) per year, causing
habitat loss and fragmentation of the remaining habitat (“Panama Forest Information and Data”).
Fragmentation exacerbates the effects of habitat loss not only by reducing habitat area but also
by increasing landscape patchiness, decreasing patch size, and increasing patch isolation (Fahrig
2003). Compared to continuous forest, these forest patches have a greater degree of edge effects
which expose organisms within a patch to the novel conditions of the surrounding environment
4
(Murcia 1995). This can have negative effects on the forest community by introducing invasive
species and increasing exposure to pollution and predators (Robinson et al. 1995). In these
fragmented landscapes, decreases in habitat area, connectivity between fragments, and canopy
heights have led to declines in howler monkey abundances (Anzures-Dadda & Manson 2006).
Fragmentation also alters habitat quality; forests that are fragmented lack large trees and thus
have less area of top food resources in comparison to continuous forests (Arroyo-Rodríguez and
Mandujano 2006). Decreased patch sizes are associated with lower population size of howler
monkeys, likely due to lower food availability (Arroyo-Rodríguez & Dias 2010). In a population
viability analysis of A. palliata in Los Tuxtlas, Mexico, Mandujano and Escobedo-Morales
(2008) concluded that in fragments smaller than 15 ha there is a 60% chance of extinction.
Highly fragmented landscapes with little connectivity and smaller patches still therefore pose a
threat to howler monkeys. Other documented threats to howler monkeys include hunting by
humans (Peres 1997), hunting by domestic dogs (Raguet-Schofield 2008; De Oliveira et al.
2008), and capture for the pet trade (Duarte-Quiroga & Estrada 2003).
Area of Study
The Burica peninsula is located in Chiriquí, Panama and is shared by both Panama and
Costa Rica. Within this peninsula, we focused our study on two areas: the towns of Bella Vista
and Limones. The majority of our field time was spent in Bella Vista, beginning at the town
center and extending to the tip of the peninsula. The rest of our study was conducted around the
town of Limones (Figure 1, Figure 2). The local economies of both Bella Vista and Limones rely
heavily on agriculture and to a smaller extent, tourism. As a consequence, much of the land has
been deforested in favor of pasture and cropland. There are a few features that distinguish the
5
two towns and thus allow for an interesting comparison. Bella Vista is foremost dominated by
cow pasture, with some small-scale personal crops. Along the coast, however, there are 3
ecotourism projects. These projects have contributed to the protection and reforestation of the
vegetation along the coast. Limones, on the other hand, has much less cow pasture but instead
has a palm oil plantation that was established in the last 5-6 years. Interestingly, much of
Limones is still surrounded by fragments of forest larger than those of Bella Vista. The human
population of the entire corregimiento of Limones was 948 in the year 2000 and 1,040 in 2010,
indicating a population growth of 9% (“Población de la Republica”).
The landscapes of Bella Vista and Limones reflect larger global trends in land use
changes. In developing countries, livestock production is the fastest growing agricultural
subsector, accounting for 33% of agricultural GDP (Steinfeld et al. 2006). This increase is in
response to both global and local demands for meat and dairy products, which have increased
with urbanization, population growth, and income (Delgado 2005). The greater demand for
livestock consequently drives the conversion of forests into pasture, which is further exacerbated
by the increased need for cropland for animal feed. The expansion of pasture/cropland and a
correlating decrease in forest cover of countries in the Neotropics that encompass primate ranges
was noted by Kowalewski et al. (2015) (Figure 3A). Along with cattle production, there have
also been trends of increasing soybean and oil palm production in these countries (Figure 3B).
With growing demands for alternative energy sources, biofuels are a popular option. Oil palm is
an attractive biofuel feedstock given its low cost of production and its high yields (Carter et al.
2007). It is also increasingly used for vegetable oils in replacement of oils with high animal and
trans fat contents. Oil palm plantations are often cultivated as commercial monocultures which
use herbicides and pesticides, thereby contributing to further biodiversity loss.
6
With these changes in land use present in the Burica peninsula, it is necessary to assess
the abundances of Howler monkeys and their ability to survive in areas with a low percentage of
forest cover and high fragmentation. Punta Burica is currently home to three species of monkeys:
Mantled Howler (Alouatta palliata), Central American Squirrel Monkey (Saimiri oerstedii), and
White-headed Capuchin (Cebus capucinus). A fourth species, Geoffrey’s Spider Monkey (Ateles
geoffroyi), once inhabited the area but disappeared sometime in the last 50 years. Our subject
species, A. palliata, is listed as Least Concern by the IUCN Red List of threatened species
(Cuarón et al. 2008). Although they are considered one of the more abundant primate species in
Panama, with increased human activity and deforestation on the peninsula it is necessary to
assess their conservation status in the area. The conservation status of the Mantled Howler
monkey was last assessed in 2008, and there has never been a comprehensive population study of
the species on the Burica peninsula. In order to analyze the impacts of land use changes on A.
palliata, a point of reference needs to first be established. Despite their status as Least Concern,
we therefore believe it is important to study A. palliata.
Our research contributes to a greater assessment of the conservation status of both the
Mantled Howler monkey and the Central American Squirrel Monkey on the entire Burica
peninsula, to be conducted by our supervisor, Dr. Ariel Rodríguez-Vargas, a researcher at the
Universidad Autonoma de Chiriquí (UNACHI) specializing in primate ecology and
conservation. Through our study, we sought to answer two questions:
1. What is the geographical distribution, demography, and behaviour of A. palliata in Bella
Vista and Limones?
2. What are the perceptions of the local communities towards monkeys and the conflicts
between the two?
7
Methods
Data collection
Research was conducted in the areas surrounding the villages of Bella Vista and
Limones, in the Barú district of the Chiriquí province. For each study area, interviews and direct
observation were conducted. We conducted research in Bella Vista in four stages between early
January and late February 2017. We began by conducting semi-structured interviews with
residents in the village and in the area south of the town leading to the tip of the peninsula.
Informants were first asked whether they had sighted monkeys in the past year. With the help of
pictures, we asked them to specify which of the three species found in the region they had seen.
In the case of howler monkeys, we asked them to describe the location, number of individuals,
and gender makeup of the groups they had sighted. They were also asked to report any locations
where others had told them that howler monkeys could be found. Finally, we asked questions
about their perception of the threats facing monkeys in the area, and their general opinion of
monkeys. The interview questions can be found in Appendix 1. In total, 15 interviews were
conducted in the Bella Vista area.
During each period of fieldwork, we used the information from interviews to establish the
locations which had a high likelihood of containing monkeys. We began by verifying each
location where a howler monkey group had been reported. Once we had surveyed these
locations, we then surveyed along the gallery forest. These wooded areas alongside streams
tended to be a good environment to find howler monkeys, which we were informed typically
avoid open areas such as pastures and beaches. During the morning (7:00-11AM) and the
8
evening (3:00-7:00PM), we slowly walked through these areas and listened for monkey howls
and barks. We also watched and listened for disturbances in the trees caused by howler monkey
movement. We used these indirect observations to help us locate and directly observe howler
monkeys. Once we made an encounter we recorded the number, age class (adult, juvenile, or
baby), and sex of the monkeys in the group. We then recorded the date, time, and GPS location
of the observation. We also characterized the behavior of the group according to four behavior
types (Table 1). Finally, we recorded information about the group’s habitat, such as forest type.
The full set of observation criteria can be found in Appendix 2. In total we recorded 21
encounters with howler monkeys in the Bella Vista study area.
We conducted research in Limones during one weekend in mid-March using the same
methodology. During this time, we obtained five interviews and three direct observations of
howler monkeys. The rest of the data points for Limones were recorded by our supervisor, Ariel
Rodríguez-Vargas, on separate occasions.
The data we collected from our interviews was then used to inform a presentation to the
community appropriate to its social context. This presentation took place April 19th, 2017. The
first goal of the presentation was to present our quantitative results regarding howler monkey
distributions, demography, and behavior and to explain what we had been doing in the
community over the duration of the study. The second goal was more educative. In the morning,
we held a presentation for the students at Bella Vista elementary school, introducing the concepts
of conservation and of habitat loss to 22 students aged 5-11. With ideas from the students, we
drew a concept map of the ways in which they can protect monkeys in their own community. In
the later presentation for all members of the community, we also spoke about the importance of
9
monkeys in the ecosystem, and the ways in which protecting monkeys can positively impact
humans as well.
This research was conducted according to the standards of McGill University and the Tri-
Council Policy Statement: Ethical Conduct for Research Involving Humans (TCPS 2). The
Course on Research Ethics (CORE) certification was obtained by members of the research team
(see Appendix 3).
Data analysis
In order to produce a visual representation of howler monkey sightings, we used ArcMap
version 10.3.1. The area around Bella Vista was shown using the aerial satellite image available
from ESRI, which was used as a basemap. We input the GPS points for each sighting and scaled
the label according to the total number of individuals in the group.
Using these maps, we calculated the area of the corresponding forested area. We chose to
omit non-forested areas (such as pastures, beaches and residential areas) since these are not
suitable habitat for howler monkeys. The area of forest cover was measured by drawing
polygons instead of using a forest cover map. Most raster maps of forest cover found online
provided exact values for the forested area, but lacked detail for the Burica peninsula due to
limited resolution. As a result, many did not include the gallery forest around Bella Vista.
Analyzing the satellite image and tracing the forested areas ourselves allowed us to achieve a
closer representation of the forested areas being utilized by howler monkeys. The surveyed area
around Bella Vista measured to be 7.74 km2. Consequently, the forested areas identified for the
purposes of calculating density occupy only 30% of the study area. This signifies that one-third
of the region around Bella Vista currently has the possibility of supporting howler monkey
10
populations. For each stream, the number of males, females, juveniles, and babies was totaled.
Density was then calculated by dividing the number of individuals by the area of the forest
cover.
To produce the map for Limones, we used the three points which we collected during the
two days we spent in Bella Vista and integrated a dataset gathered by our internship adviser, Dr.
Ariel Rodríguez-Vargas. Due to our limited data points, we did not attempt to analyze this map
and present it only for the use of future studies.
Results and Discussion
Biological data
Geographical distribution
The map of Bella Vista clearly illustrates the fragmentation of the forest around Bella
Vista, as well as the howler monkey’s dependence on the forested areas (Figure 4). The overall
density of howler monkeys in the total forested area is 63 individuals/km2, and the density for the
entire region including non-forested area is 9 individuals/km2.
Figure 5 illustrates the forested area in and around Bella Vista in relation to the closest
stream. The density of each area of these patches of forest is indicated. For the total area between
Quebrada del Medio and the tip of the peninsula, including forested and non-forested area, the
population density was 19 individuals per km2. A high variance in density can be observed
between the different streams. While Quebrada Resbalosa is connected to a relatively large area
of continuous forest as well as two private reserves (Tigre Salvaje and Mono Feliz), it has one of
the lowest population densities (28 individuals/ km2). It is probable that the groups counted in the
11
area surrounding Quebrada Burica, which had a density of 218 individuals/ km2, benefit from
food availability and protected forest at Mono Feliz.
The population density of A. palliata can be affected by a variety of factors. A literature
review by Chapman et al. 1998 analyzes over 80 population studies of howler monkey
populations in order to understand the effect of habitat productivity on population characteristics.
The high variability in population densities suggested that recent events such as habitat
alteration, hunting, food tree crop failure, and disease had a high impact on the groups (Chapman
& Balcomb 1997). Especially relevant is a long-term study on Barro Colorado Island, which
illustrates the high variability of a single population over time, from an estimated 1500
individuals to less than 900 (Milton et al 1996). In cases where several groups were studied
within the same area, increased levels of protection and food availability favored higher
population density, however, long-term studies should be favored in order to understand the
dynamics of howler monkey populations (Chapman & Balcomb 1997). Given the proximity to
human populations, recent deforestation in the area, and the fragmentation of the habitat, it is
likely that recent events in the history of the population have had an impact on population
density. Without a detailed understanding of these events, it is difficult to establish their impact
on individual groups in the study area. A long-term study comparing population density across
time could yield a better understanding of the population dynamics of A. palliata in Bella Vista.
The data collected in Limones yielded a preliminary exploration of the howler groups in
the area. While further study is required to verify and quantify the total number of groups in the
region, a map was produced to illustrate the information available thus far (Figure 6). Although
these points have not been analyzed to interpret the possible reoccurrence of troops, this
12
information can be used for future research. Table 4 summarizes the points which were gathered
in the region, in the case where the groups could be verified and counted.
Behavior
Our results showed that out of the 19 encounters we had with A. palliata and recorded
behavior, 53% occurred while howler groups were resting, 21% while some members of the
group were resting and others were eating, 16% while the entire group was eating, and only 10%
while the entire group was traveling (Figure 7). The breakdown of behavior by time of day was
largely variable, but we did see a few trends. We found that the howlers we encountered mostly
spent the morning resting and traveling, rested during midday, and spent the evening resting and
eating (Table 2). The only time we observed howler groups traveling was during the morning,
and a majority of eating encounters took place during the evening.
Our behavior results suggest that A. palliata spends a majority of the time resting,
followed by eating, and finally spends a short amount of time traveling. This is consistent with
other studies that show howler monkeys to be a relatively inactive species, likely due to their
low-calorie diet (Milton 1980). A review of the literature surrounding the diet of Alouatta
conducted by Kowalewski et al. (2015) found that howlers spend on average 19.7 ± 6.9% of the
time eating, a finding that is consistent with our own results.
Because our encounters were biased towards the early morning and the evening, this may
have skewed the behavior results. These were the times that the monkeys tended to howl, and we
found them extremely hard to encounter during the times they were not howling. For this reason,
we preferred to focus our sampling efforts to the morning and the evening, using midday to
conduct interviews. Based on the few encounters we had during midday, we found that the
13
howlers preferred to rest during this time, likely due to the heat. We only encountered traveling
groups during the morning, suggesting that the howlers spend most of the day within a small
range. However, howler monkeys repeatedly use a few routes to travel between feeding and
sleeping sites, so given our biased sample timing, we may have missed other times that howlers
travel, such as afternoon or late evening. The small amount of encounters we had with traveling
groups is consistent with the literature that documents that day range of all howler monkeys
species is on average less than 600m (Kowalewski et al. 2015). Finally, most of the eating
encounters were observed during the evening. However, given our low sample size for the
behavior data these results should only be considered as preliminary observations. The behavior
of howler monkeys in Bella Vista and Limones must be furthered studied with a greater sample
size in order to test for any statistically significant trends.
Demography
The average group size that we encountered in Bella Vista was 6.8 ± 4.6, and in Limones
was 8.1 ± 3.4 (Table 3). In La Pacifica, Costa Rica mean group size of A. palliata in fragmented
habitat was 12.6 (Clarke & Zucker 1994). A 23-year study of A. palliata on Barro Colorado
Island, Panama found that mean group size in continuous forest was 19.0 ± 6.0 (Ryan et al.
2008). In La Pacifica, Costa Rica mean group size of A. palliata in fragmented habitat was 12.6
(Clarke & Zucker 1994). Comparing our results to these studies, we can thus see a potential
impact of fragmentation on group size in our areas of study. Mean group size was slightly larger
in Limones, due perhaps to a lesser degree of habitat fragmentation in the area compared to Bella
Vista. Group sizes more closely match the fragmented forests of La Pacifica, and are much
14
smaller than that of Barro Colorado Island. It is important to consider, however, the limitations
of our study. Given our time limitations, we could not follow the groups for very long. It is
possible, therefore, that some of the howler groups we encountered were merely subgroups that
split off to forage. This would bias our results towards smaller group sizes, when in reality the
groups may have been larger. Nevertheless, we can still say something about the presence of a
lot of small groups. It has been documented that when resources are clumped at low densities (as
is the case in landscapes with high fragmentation), howler monkeys are found in smaller
subgroups (Chapman 1990).
Social data
Perceived threats
Through our interviews, we identified several perceived threats to howler monkeys:
deforestation, capture for sale, capture for use as personal pets, hunting by humans for sport,
hunting by humans for food, hunting by dogs, and climate change. In both Bella Vista and
Limones, we found that the most common perceived threat was deforestation (Figure 8). Capture
for sale and hunting by dogs were the second most common perceived threats. We learned from
three people that it was more common to keep monkeys as pets in the past, but over the last 15
years this has decreased. Six of our interviewees said that howler monkeys are not kept as pets in
the area at all. In general, people in the area don’t really keep howler monkeys as pets. It is more
common to keep the squirrel monkeys as a pet, but even this has decreased in the last 15 years.
15
In Limones, none of our interviewees mentioned the second most common perceived threats
in Bella Vista (capture for sale and hunting by dogs). Instead, they perceived hunting by humans
for food and for sport as the other threats to howler monkeys in the area. It is important to note
that all five of our interviewees perceived deforestation to be a threat. This is may be due to the
close proximity of Limones to an oil palm plantation, which may be a more evident form of
deforestation since it occurred more recently than the deforestation of Bella Vista. However, this
may also be an effect of small sample size and thus should not be too greatly emphasized without
further study.
General observations
The preferred monkey of our interviewees in Bella Vista was a tie between the squirrel
monkey or all three types (Figure 9). Howler monkeys and capuchins were both least favorite,
with only one person voting for each. Despite this tie, we heard many negative opinions towards
the capuchins throughout our interviews; seven people told us that the capuchins are bothersome
because they eat crops and eggs and are often aggressive. There were much less negative views
towards the howler monkeys, which were only disliked by three people because they are
considered ugly and noisy. In general, people are pretty indifferent to howler monkeys, neither
disliking nor particularly liking them.
In Limones, a majority of people said that they liked all three types equally. While the
squirrel monkey and the capuchins tied for second favorite, no interviewee voted for the howler
as their favorite. Interestingly, absent from our interviews in Limones were the strong negative
feelings towards capuchins that we found in Bella Vista, with only one person mentioning
instances of them eating crops. We hypothesize that this may be because a greater degree of area
16
around Limones is residential, lacking the livestock and crops that are more typical of Bella
Vista. Capuchins may thus be less of a nuisance to people in Limones. We must again, however,
take into account our small sample size of interviews for Limones; the opinions of the few we
interviewed may not accurately represent the views of the entire town.
Future conservation ventures
For the social part of our project, we strove to understand the social context of Bella
Vista and Limones and the relationship of the local communities to monkeys. Although the
purpose of our study was neither to identify nor implement conservation strategies, the
information that we gathered is the preliminary step in doing so in the future. For that reason, we
believe it is important to discuss what the process of implementing those conservation strategies
should entail. This requires a brief discussion of approaches to conservation.
The concept of conservation has continuously evolved throughout history. Early
conservation movements emphasized an intrinsic value of nature, advocating for its preservation
as a pristine environment untouched by humans. This is in contrast with later movements which
had a greater focus on the instrumental value of nature. Gifford Pinchot, the first Chief of the
United States Forest Service, was a principal advocate for this, saying that “the purpose of
Forestry, then, is to make the forest produce the largest possible amount of whatever
crop or service will be most useful, and keep on producing it for generation after
generation of men and trees” (Pinchot 1998). In these early approaches, the point of conservation
then was to protect nature in order to maximize its use for humans both for the present and for
the future.
17
The idea of the instrumental value of nature has remained in modern concepts of
conservation, which emphasize placing an economic value on the services that an ecosystem
provides. The idea behind this is that in this post-neoliberal capitalist world, people will only
care about protecting nature if they understand the costs associated with its loss. The ecosystem
services concept thus seeks to maximize the costs and benefits associated with the loss or
protection of a particular ecosystem: for example, assessing whether a piece of forest will have
greater economic value to the greatest number of people in its intact state, which provides
services such as carbon sequestration and water purification services, or in its conversion to
timber (Collard et al. 2014).
The problem with the preservationist approach is that ecosystems are not static and
pristine; they are dynamic and change over time even without human intervention. Both
preservation and neoliberal conservation are furthermore problematic in that they often come at
the expense of local communities. In its commodification of nature, neoliberal conservation often
feeds resource extractive processes in developing countries. Neoliberal conservation advocates
for partnership of conservation with corporations (Kareiva et al. 2012), promising increased
public participation and property rights to local communities, in addition to green business
practices. In reality, these approaches are detrimental to communities, often displacing local
people while simultaneously excluding them from the benefits of the conservation projects,
which are received instead by external actors (Igoe, J. & Brockington 2007). A prime example of
this was the protection of the Panama Canal watershed, outlined by Carse (2012). In the 1970s,
concerns over water supply for the Panama Canal necessitated a management approach that
emphasized forest conservation. This management focused largely on protecting the forests
around the Canal and addressing the deforestation activities of the people who lived in the
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watershed. For example, forest guards were employed by the Panamanian government in order to
protect the watershed from campesino farmers. Further ignoring the local context and the key
processes important to the swidden agricultural system, a law was passed delineating rastrojo
(land burned post-crop growth) older than 5 years as protected forest. As a result, campesinos
began to clear rastrojo earlier than they normally would have, decreasing the productivity of the
land. Although protected areas strive to integrate conservation with ecosystem services (in this
case, increasing the retention of water in order to increase the economic return of the Canal),
they thus often negatively impact local communities. The failure of protected areas has been
documented: in Thailand, for example, local support for Marine Protected Areas was minimal
because they were perceived to have negative impacts on fisheries and agricultural livelihoods
(Bennett & Dearden 2014). Without community support, conservation efforts are more likely to
fail. Conservation projects are thus successful when they are designed for the particular social
and economic context of an individual community (Brooks et al. 2013). Furthermore, they must
be designed not simply for but also with the local community; this involves public participation,
allowing all potentially impacted actors the chance to voice their opinions and take part in
decision making (Webler & Tuler 2000).
For these reasons, we believe that future attempts to implement conservation strategies in
Bella Vista and Limones should involve directly working with the community. As we saw
firsthand, there is a huge economic dependence on cattle farming, which requires a lot of both
space and time. In an attempt to protect monkeys, then, it is important not to overlook the needs
of the local community. Significant barriers exist which may hinder the accessibility of
conservation initiatives. Limited access to internet and electricity, as well as physical isolation,
can make promotion and organization of projects difficult. In Bella Vista, the roads leading to
19
the homes further from the town are not usable throughout the entire year, further isolating those
families. In some cases, conservation is not a priority simply because individuals feel that they
have other, more serious concerns. In other cases, individuals care deeply about wildlife but lack
the time and resources to carry out larger-scale projects within their community. Part of
implementing conservation strategies may thus involve education, which is why for our
presentation we focused on the importance of protecting forest both for the ecosystem and for its
importance to the humans who live there. Future projects can also focus on starting dialogues
between community members and allowing various stakeholders to contribute to conservation
efforts in ways which are suitable to their capabilities and interests.
According to AMBIENTE Law 1, article 23 for rivers and streams in Panama a strip of
forest must be left equal to the width of the channel on both sides, and this can never be less than
10 meters. Although from the map we can see that the streams on the area are still forested, when
we surveyed alongside them we found that in most cases this law was not followed, with pasture
often ending close to the edge of the streams. The lack of compliance to and enforcement of this
law is evidence of the need to involve the local community in protecting the environment. Within
both Bella Vista and Limones, we encountered a few people dedicated to the conservation of
monkeys. We spoke with one man in Limones who had constructed a ladder bridge above the
main road in order to connect the forests near his house to the forest across the street. Acts like
these done by community members serve as important stepping stones to implementing
conservation projects throughout the community.
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Conclusion
In the context of a study area with a great degree of habitat loss combined with a high
diversity of wildlife, it is important to assess the impacts of these land use changes on individual
species. Howler monkeys are an interesting subject due to their flexible diet which allows them
to persist in areas of anthropogenic disturbance. For this reason, there are still populations of
mantled howler monkeys living in the Burica peninsula. However, we found that the
fragmentation of the habitat in our study areas is indeed affecting A. palliata.
Maps were produced for Bella Vista and Limones, illustrating the geographic distribution
of our sightings, as well as some points gathered by Dr. Ariel Rodriguez-Vargas. These show the
monkey troops’ dependence on forested areas and highlight the high proportion of deforested
area for both regions. These maps can also be used as an educational tool. For Bella Vista, the
forested area covered 30% of the region between Quebrada del Medio and the tip of the
peninsula, showing high fragmentation. Troops were present in both gallery forest and areas of
continuous forest. Monkey sightings were dispersed across the forested area, and population
density showed high variability between different regions of the study area. The significance of
these density values is difficult to evaluate based on a single population study, and a long-term
study would be useful to understand the dynamics of the troops around Bella Vista. In addition to
showing the current state of A. palliata distributions and densities in Bella Vista and Limones,
our maps thus serve as an important preliminary record to be compared against in future studies.
Although howler monkeys are a highly adaptable species, they are still unable to survive past a
certain degree of habitat loss and fragmentation (Mandujano and Escobedo-Morales 2008). For
example, inbreeding can occur in fragmented forests due to a loss of forest connectivity
(Oklander et al. 2010). The level of inbreeding is an interesting topic that could be explored in
21
future studies in order to give insight into the connectivity of the forest fragments. For our study
we divided the area into fragments based on streams, but its likely that there is still a degree of
connectivity and gene flow between the forests of these streams due to the forested areas along
the coast.
The average group size that we found was similar to those found in other fragmented
landscapes and much smaller than those of continuous forests, indicating that fragmentation
indeed is having an effect on group size in Bella Vista and Limones. Our behavior data matches
what is typically found in the literature, indicating that behavior (time spent eating, resting, and
traveling) is not influenced by decreased habitat. In a study examining the effects of fragment
size on various behavioral factors of howler monkeys, no correlation between fragment size and
distance traveled daily was found (Bicca-Marques 2003). Rather than travel further to find food,
howler monkeys adapt their diet to the area they inhabit.
Finally, the analysis of our interviews in Bella Vista shows a preference for squirrel
monkeys, a dislike for capuchins, and an indifference towards howler monkeys. The dislike
towards capuchins due to their tendency to eat crops could be used to help make the case for
reforestation, since crop raiding is known to occur by both capuchins (Mckinney 2010, Freitas et
al. 2008), and howler monkeys (Bicca-Marques 2009) when habitat is decreased. This point was
also brought up by a community member during our presentation. Furthermore, deforestation is
the most common perceived threat to howler monkeys in the area. However, this was only
mentioned by 50% of our interviewees as a threat, possibly indicating the need for more
education on the subject. Unfortunately, our sample size for Limones was too small to make any
real conclusions regarding the opinions of the community towards monkeys.
22
Finally, we recommend the continued involvement of community members in the
identification and implementation of conservation strategies. We hope that our results and
observations can be a helpful preliminary step in empowering the communities in the Burica
peninsula to manage and protect their environment. The students and community members that
we encountered during our research exemplified the immense potential in this area, and we are
interested to see how Bella Vista and Limones will respond to growing environmental
challenges.
Acknowledgements
We would like to offer our deepest thanks to the communities of Bella Vista and Limones for
participating in this project and offering us their time and knowledge during our research.
We would also like to thank the Universidad Autónoma de Chiriquí for enabling this project. We
would especially like to thank Ariel Rodríguez-Vargas for offering his support and expertise, as
well as the time taken to guide and assist us in carrying out our work.
We would like to offer special thanks to David Teichmann; Shawn, Shena, Reina and Lily
Lockwood; Edwin Castillo; Silvia and Junior Ramírez; Mixila and Veronica Gonzalez; and
Manuel and the staff of the Centro Educativo de Bella Vista.
23
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Figures and Tables
Figure 1: Our study area within Panama
Figure 2A: Bella Vista study area Figure 2B: Limones study area
27
Figure 3A: Increase in pasture/cropland and
corresponding decrease in forest cover
(Kowalewski et al. 2015)
Figure 4: Map of Bella Vista
Figure 3B: Increase in soybean and oil
palm production in countries with howler
monkeys (Kowalewski et al. 2015)
(Kowalewski et al. 2015)
28
Figure 5: Map of Bella Vista by stream
Figure 6: Map of Limones
29
Figure 7: Behavior of howler monkeys by percentage of encounters.
Figure 8A: Perceived threats to howler monkeys in Bella Vista
0
1
2
3
4
5
6
7
8
Deforestación Capturaparalaventa
Capturaparamascota
Caceríaporlagentepara
comida
Caceríaporlagentepara
deporte
Caceríaporperros
Cambioclimático
Núm
erodepersonas
Tipodeamenaza
AmenazaspercibidasalosmonosaulladoresenBellaVista
Traveling10%
Eating16%
Eating/Resting21%
Resting53%
Percentage of encounters spent resting, traveling, or eating
30
Capuchin20%
Squirrel20%
All 360%
Favorite type of monkey in Limones
Howler12%
Capuchin
12%
Squirrel38%
All 338%
Favorite type of monkey in Bella Vista
Figure 8B: Perceived threats to howler monkeys in Limones
Figure 9: Monkey preference by species in Bella Vista and in Limones.
0
1
2
3
4
5
6
Deforestación Capturaparala
venta
Capturapara
mascota
Caceríaporla
gentepara
comida
Caceríaporla
gentepara
deporte
Caceríapor
perros
Cambio
climático
Númerodepersonas
Tipodeamenaza
AmenazaspercibidasalosmonosaulladoresenLimones
31
Table 1: Description of behavior categories
Type of behavior Description
Resting The entire group was resting only.
Eating The entire group was eating only.
Resting/Eating
Part of the group was resting and part of the
group was eating.3
Traveling The entire group was moving through the trees
to a different location.
Table 2: Behavior of howler monkeys by time of day.
Resting Eating/Resting Eating Traveling
Morning 7AM-11AM 4 2 0 2
Midday 11AM-3PM 3 0 1 0
Evening 3PM-7PM 3 2 2 0
Table 3: Average group size in different areas of study
Location Mean number of monkeys per group (±
SD)
Bella Vista 6.8 ± 4.6
Limones 8.1 ± 3.4
La Pacifica – bosque fragmentado
(Clarke & Zucker 1994)
12.6
Isla Barro Colorado – bosque continuo
(Ryan et al. 2008)
19.0 ± 6.0
32
Table 4: Demography and area of streams in Bella Vista
33
Appendix 1: Semi-Structured Interviews
1. Fecha
2. Nombre
3. Localidad de la entrevista (con punto GPS)
4. ¿Cuántos años tiene?
5. ¿Cuántos años tiene de vivir en esta zona?
6. ¿Ha visto monos este último año?
7. ¿Qué clases de monos ha visto este último año (Mono aullador, mono tití, mono
carablanca)?
8. ¿Hay clases de monos que ha desaparecido de la zona?
9. ¿Dónde ha visto los monos aulladores?
10. ¿En cual tipo de medio ambiente ha visto monos aulladores?
11. ¿Bosque nuevo, bosque secundario, rastrojos, bananales, bosque de galería, platanares,
cocoteros, otras frutales (caimito, guaba, mango), cercas vivas?
12. ¿Cuales tipos de árboles comen los monos? ¿Comen las hojas o las frutas?
13. ¿Cree usted que los monos aulladores son a veces capturados para la venta o para
mascotas? ¿Sino, en el pasado? ¿Hace cuánto tiempo?
14. ¿Cree usted que la deforestación afecta a los monos aulladores? ¿En su opinión, hay otras
cosas que pueden afectar a los monos?
15. ¿Conoce de otras lugares donde se encuentran monos?
16. ¿Usted tiene comentarios adicionales?
Opiniones
1. ¿En general, le gusta usted la presencia de los monos en el área? ¿Todos tipos
carablancas, titíes y aulladores?
2. ¿Cual es su tipo de mono favorito? ¿Porque lo prefiere?
3. ¿Hay razones porque no le gustan los monos?
4. ¿Cree que en general, la gente en el área le gustan los monos?
5. ¿En su opinión, cuáles beneficios tiene la presencia de los monos?
Appendix 2: Direct Observations
1. Date
2. Time
3. GPS point
4. Elevation
5. GPS device
6. Description of location (property owner, district, county)
7. Site ownership or jurisdiction (Private, municipal, federal)
8. Land use of area
9. Description of environment (Proximity to paths, bodies of water and open areas. Type of
forest, possible sources of food)
34
10. Individuals in groups
11. Number of females
12. Number of males
13. Number of juveniles
14. Number of infants
15. Total
16. Behavior
17. Eating? How many?
18. Resting? How many? What type(s) of trees?
19. Other activities? How many? What type(s) of trees?
20. Did the group travel? If so:
21. New time
22. Type(s) of tree
23. New GPS point
24. Other observations: Mother separate from group? Parasites?
Appendix 4: CORE certification
35
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