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Research topics in:
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Zoology |
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Alger, Sarah, "Resting Site Microhabitat Selection of Tapirus bairdii During the Dry Season in Corcovado National Park, Costa Rica". Adv. Christopher Vaughan. Macalester College. 1997. 15pp. I radiotracked two Baird's tapirs (Tapirus bairdii) in March and April 1997 to describe diurnal resting sites in Corcovado National Park, Costa Rica and test the hypothesis that tapir selection of diurnal resting sites is based upon physical microhabitat parameters such as: habitat type, substrate type, substrate hydration, percent ground and breast-height vegetation, percent canopy coverage, shade and slope. Fifteen resting sites were located (7 dry forest sites, 7 mud holes, and 1 stream site) and 33 observations were made. All sites were in secondary forest. Dry sites had a significantly higher percent canopy coverage than did wet sites (p = 0.005), although percent coverage of all sites was greater than 55% and all hourly observations were in part or full shade. Time of day effect on percent coverage, substrate type, and substrate hydration selected was not significant (p = 0.358, p = 0.064, p = 0.051, respectively). Time of day effect on shade and site type selected was significant (p = 0.038 and p = 0.037, respectively). The effect of weather on substrate type, substrate hydration, site type, and percent coverage were all significant (all p < 0.001). Mean number of visitations per site was 2.6 (SD = 2.1). Balsavich, Luke, "Determining the presence of reptile and amphibian species in San Luis, Monteverde." Adv. Gerardo Chaves C. Ripon. 2003. This project seeks to determine which species of reptiles and amphibians reside in the San Luis region of Monteverde in order to develop a species list that will aid in understanding Costa Rica's biological systems. The study involves the capture, inventory and preservation of specimens, followed by the cross referencing of information on the specific area where the specimen is captured, habitat, humidity and elevation with information reported in "The Amphibians and Reptiles of Costa Rica" by Jay Savage (2002). Bastiaans, Elizabeth, "Habitat Selection in the Green Iguana (Iguana iguana) along the Banks of the Tempisque River near Palo Verde National Park, Costa Rica." Advisor: Michael McCoy. The University of Chicago. 2005. 40pp. I studied habitat selection in the green iguana (Iguana iguana) along the banks of the Tempisque River near Puerto Humo de Nicoya, Guanacaste, Costa Rica, during March and April of 2005. I collected information on the preferences of green iguanas for gallery forest versus mangrove and on their microhabitat preferences regarding distance from water, vegetation density, substrate, perch height, branch diameter, tree height, and tree diameter at breast height. I also collected data on the sex and size of iguanas located in each habitat category and analyzed whether the types of habitats selected by the iguanas were dependent on sex and size using chi-square analysis. I found significant differences between the average numbers of iguanas observed per day in mangrove versus gallery forest, dense versus open vegetation, 3 classes of distance from water, 3 classes of perch height, 4 classes of perch branch diameter, 4 classes of tree height, and 4 classes of tree DBH. I found that iguanas' preference for dense vegetation over open vegetation and preference for branch diameter were dependent on size and that iguanas' preference for habitats close to water, preference for perch height, preference for tree height, and preference for tree DBH were dependent on both sex and size. This research provides a preliminary description of the structural characteristics of habitats preferred by the green iguana, as well as some insight into the factors that may underlie these selections. Bentz, Christina, "Microhabitat Parameters of Mud Bath and Resting Sites for Two Herds of Tayassu pecari in a Lowland, Tropical Rainforest". Adv. Mike McCoy. Coe College. 1997. 13pp. Although little research has been done on the white-lipped peccary, virtually no information regarding its microhabitat utilization has been accumulated. This study was conducted on two herds of T. pecari for resting and mud bath sites at the Sirena Biological Station of Corcovado National Park, Costa Rica during the dry season months of March and April, 1997. Other studies have been conducted on this species, though it is documented by Donkin (1985), as the less closely observed species, and "further information regarding its actual habitat is desirable." (Husson 1978 in Donkin 1985). March (1987) also feels that this scarcely known species requires urgent investigations to aid in its conservation, and that it is threatened or in danger of extinction in Costa Rica, México, and Guatemala. Peccary herds were encountered on 17 different occasions during this study. Parameter data was compiled for each resting and mud bath site. These include: area (meters squared), percent canopy cover (percent class system), composition of ground cover (percent class system), soil temperature (degrees Celsius), air temperature (degrees Celsius), total time resting (minutes), when the resting period occurs (morning/afternoon), number and identification of plants found in the resting areas, total number of peccaries observed resting, number of trees in site (if DBH is less than 10 cm), DBH of trees in site (greater than 10 cm DBH) and percent water of mud baths. Tracking the herds was conducted using TR-4 Telonics radiotelemetry equipment with an H antenna and direct observations were made. Berger, Ramona E., "The Calling Patterns of Four Dentrobatid Frogs and The Courtship Behavior and Movement Patterns of Dendrobates Pumilio." Adv. Federico Bolaños. Lawrence, 1991. 30pp. I studied the courtship behavior and daily movements of Dendrobates pumilio frogs, and the daily calling patterns of D. pumilio, Colostethus nubicola, C. talamancae, and Phyllobates lugumbris at Hitoy-Cerere Biological Reservation in Limón Province, Costa Rica. The D. pumilio frogs called most in the morning. In correlation with this, courtships were easier to find in the morning. Males had less average movement than females. This Movement was consistent throughout the day, although the type of substrate where they were found changed through the day. There were behavioral differences from other studies (more persistent males during courtship and larger size egg clutches). These differences may be explained by a combination of dry conditions and the different location from the other studies. The calling patterns varied extremely with different weather conditions. On dry days less frogs called, while calling increased on days after and during rain. P. lugumbris and C. talamancae had little pattern in their calling, while C. nubicola called more in the morning and late afternoon. Differences in calling patterns may be a result of different calling techniques and weather sensitivity. Bremer, Mark A., “Parental Nest Visitation of the Scarlet Macaw (Ara macao), ACOPAC, Costa Rica.” Adv. Christopher S. Vaughan. Colorado College '01. 2000. 10pp. Nest visitation and behavior of adult Scarlet Macaws (Ara macao) was studied during the nesting season (February-April, 2000) in the Hacienda Quebrada Bonita, 9°47'N, 84°37'W, in the Central Pacific Conservation Area (ACOPAC), Costa Rica. It was found that parental time at nest, number of visits, and duration of visits all decreased significantly during nestling development. One adult was present 86% of the time during incubation days -28 to 0, averaging 83 minute stays, while between chick days 44 to 82, parents averaged 24 minute stays, spending only 13% of the time present. Bremer, Mark A., “Artificial Nestbox Use by the Scarlet Macaw (Ara macao), ACOPAC, Costa Rica.” Adv. Christopher S. Vaughan. Colorado College '01. 2000. 7pp. Artificial nest box visitation and use by adult Scarlet Macaws (Ara macao) was studied during the nesting season (February-April, 2000) in Carara National Park, the Hacienda Quebrada Bonita, Club Punta Leona, and Quebrada de Gandado, 9°47'N, 84°37'W, in the Central Pacific Conservation Area (ACOPAC), Costa Rica. Twenty-five nests were monitored for A. macao activity, those with activity were climbed and inspected for signs of nesting. It was found that 13 nests were prepared for nesting, 3 had eggs laid, and 1 fledged chicks. |
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Cullum, Robert Dan, "White Faced Monkey Troop Ecology in Curú National Wildlife Refuge." Adv. Claudette Mo. Colorado. 1992. 15pp. Troop movement, home range, habitat use, and activity patterns of a troop of 8 white-faced monkeys, Cebus capucinus, were studied in a lowland forest Curú National Wildlife Animal Refuge at the end of the dry season (March and April) of 1992. The troop home range was .60 km2 and traveled an average of 2.83 km +/- .68 daily. Four basic diurnal activities were defined: feeding, resting, travel, and miscellaneous. Feeding was greatest between 0500-0900 and 1500-1800 hours. Movement and miscellaneous activities were relatively consistent throughout the day. Resting occurred mostly between 1000-1500 hrs. The capuchins have a diverse diet consisting mostly of fruits, seeds, and insects. This primate fed on 31 species of plant from 21 families, insects (including several: Orthoptera, Cicadidae, Vespidae, Formicidae, and Tremitidae), and several animals: three Iguanidaes, one Hylidae, and one squirrel Sciurus variegatoides. Division of time spent foraging was 56.2% fruits and seeds, 35.9% animals, and 7.7% plant material. Durno, Stephanie, "Observations on Interspecific Relationships in Range Size, Habitat Usage, and Activity Patterns of the Jaguar (Panthera onca) and the White-lipped Peccary (Tayassu pecari) in Corcovado National Park, Costa Rica." Adv. Eduardo Carrillo. Colorado. 1998. 14 pp. An adult female jaguar (Panthera onca) and four herds of white-lipped peccaries (Tayassu pecari) were followed during March and April of 1998 in Corcovado National Park, Costa Rica using radio telemetry to determine interspecific relationships in range size, habitat usage, and activity patterns. The jaguar's range size during the study was 4.24km2, while that of all peccary herds was 1.44 km2. The peccaries' range comprised 34% of the jaguar's territory, while the jaguar was active in 100% of the peccaries range. The jaguar tended to use one area of her range for 1-3 days before moving to a new area and moved an average of 2.7 km/day. Both species showed both nocturnal and diurnal activity, but highest frequency of activity was displayed during daylight hours. High human presence during the study appears to have influenced all activities studied. Elmeer, Heather, "The Importance of Corridors to White-faced Monkeys, Cebus capucinus, in Curú National Wildlife Refuge." Adv. Christopher Vaughan. Grinnell College. 1994. 16 pp. During March and April of 1994, the ecology and corridor use of a troop of 34 white-faced monkeys, Cebus capucinus, were studied in the lowland farm area of Curú National Wildlife Refuge, Costa Rica. The main focus of the study was how and to what extent the study troop utilized three different corridor types: simple living fence rows, pseudo-riparian corridors, and riparian strips. During March and April of 1994, data on the habitat use, activity, diet, and movement patterns of Cebus capucinus were taken every five minutes from 0530-1730. The monkeys spent a significantly greater amount of time in pseudo-riparian and riparian corridors than in all other habitats (1-factor ANOVA, d.f.=11, F=31.4, p<0.00009). They rested more in the middle of the day (0830-1330) and fed and moved more in the early morning (0530-0830) and late afternoon (1330-1730) (2-factor ANOVA, d.f.=33, F=13.5, p<0.00009). The study troop consumed 24 species of plants, several species of insects, and four species of vertebrates throughout the study period. They spent significantly more time feeding on riparian strips and pseudo-riparian corridors than in simple living fence rows (X2=4444, d.f.=2, p<0.00009). The relative importance of each corridor type to the white-faced monkey troop was assessed. The results of this study may help to define the type of corridors required by Cebus capucinus to persist in agriculturally-altered land, and may aid in a better understanding of the importance of corridors to wildlife in general. Foehner, Jennifer, "Role of the wild rabbit (Sylvilagus dicei) as seed disperser in a secondary montane rainforest habitat in the Talamanca range." Adv. Carlos Valerio. Monmouth. 1994. 7pp. This project attempted to determine the possible role of a wild rabbit species (Sylvilagus dicei) in the restoration of a successional montane rain forest through seed dispersal near La Trinidad de Dota, Costa Rica. The project involved a period of collecting fecal samples to determine the presence of seeds, identification of species, collecting seed samples from fruiting plants, and germination trials to determine differences between seeds that have passed through the digestive tract and those that have not passed through the digestive tract. Only one species of seed was found in the fecal samples and germination trials yielded no results during the time of observation. Griffith, David, "The Behavior and Habitat Selection of Ctenosaur similis in Punta Leona, Costa Rica". Adv. Chris Vaughan. Colorado College. 1997. 11pp. A study was conducted on the iguanid, Ctenosaur similis, observing behavioral and habitat selection changes throughout the day. The project took place on the Pacific Coast of Costa Rica. Ctenosaurs were found to devote the majority of their time to resting. Also both their behavior and their habitat selection was dependent on the time of day. Humans were found to have an effect on Ctenosaur behavior. |
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Gronau, Rachel, "Home Range, daily troop movement, habitat usage, forest level occupied, and activity patterns of a troop of Saimiri oerstedi citrinellus in Manuel Antonio National Park, Costa Rica." Adv. Grace Wong. Ripon. 1998. 20pp. Home range, daily troop movement, habitat use, forest level occupied, and activity patterns of a troop of thirty squirrel monkeys (Saimiri oerstedi citrinellus) was studied in Manuel Antonio National Park, a tropical wet forest in Costa Rica, between Mar. 2 and Apr. 25, 1998. The home range during these two months was found to be 27 ha and the daily troop movement averaged 2.6 km. This troop spent more time in the intermediate and mature secondary forests and significantly less time in the mangrove and primary forest (F= 7.51; DF=1; P= 0.0001). The troop occupied the middle level for a greater amount of time than any of the other levels (F= 25.90; DF=1; P= 0.71). The level occupied by the individuals was not dependent upon whether it was a male, female, or juvenile (x2 =178.820; DF= 6; P= 0.00). The amount of time spent in each defined activity was not significantly different (F= 1.5; DF=1; P=0.2825) nor were the activities dependent upon the time of day (x 2 = 342.603; D.F.= 36; P= 0.00). The frequency of the each activity versus the time of the day did differ statistically between males, females, and juveniles (Resting- x2 =105.35; DF= 22; P= 7.396E-13; Foraging fruit- x2 =59.035; DF= 20; P= 1.003E-5; Foraging insects- x2 =111.937; DF= 22; P= 4.974E-14; Traveling- x2 =96.525; DF= 22; P= 2.595E-11). Hall, Tiffany, “The effects of tourism on the behavior of white-faced capuchins (Cebus capucinus) in Manuel Antonio National Park, Costa Rica.” Advisor Grace Wong. Colorado College. 1999. 23pp. With the increase in tourism in Manuel Antonio National Park, Costa Rica, a troop of white-faced capuchins (Cebus capucinus) have increased their contact with humans in efforts to forage for tourist food. Little is known about the effects that this human contact is having on the behavior of the troop. Therefore, this troop was studied during March and April 1999, and, using an instantanious focal animal method, various behaviors of the troop were recorded. The behavior of the troop on the beach, where there were more people, was compared with the behavior in the forest. Each behavior that was recorded was found at significantly different frequencies between the two sites. Behaviors that would indicate higher stress levels were seen in higher frequencies on the beach. To conclude, tourism was seen to have a detrimental effect on the behavior of this troop. Results from this study would caution people from feeding and maintaining close contact with this species in particular and would encourage careful planning to prevent high impact tourism, such as in Manuel Antonio. Hertzler, Bradley K., "Density and Habitat Selection of Four Non-human Primate Species in Matapalo, Osa Peninsula, Costa Rica". Adv. Chris Vaughan. St. Olaf College. 1997. 34pp. Density and habitat selection of four non-human primate species were calculated during the late dry season (March and April) of 1997 in Matapalo, Osa Peninsula, Costa Rica, by walking five transects. Howler monkeys (Alouatta palliata) and spider monkeys (Ateles geoffroyi) selected late secondary growth and had average densities of 0.74 ind/ha and 0.78 ind/ha, respectively. Squirrel monkeys (Saimiri oerstedii) and white-faced monkeys (Cebus capucinus) selected early secondary growth with the white-faced monkeys additionally selecting beach growth. Their average densities were 0.86 ind/ha and 0.47 ind/ha, respectively. Average densities and habitat selections from this study were compared with other New World studies. Johnson, Patricia, "Bat Diversity and Distribution in Six Different Habitats of Curú Wildlife Refuge." Adv. Claudette Mo. Cornell. 1992. 18pp. Curú wildlife refuge is a privately owned government protected refuge located within finca Curú. This farm contains a number of agricultural areas in addition to "natural" forested habitats. Six of these different habitats were sampled to determine the overall species diversity and distribution of bats within this unique refuge. Habitats sampled include: in a coconut grove next to the beach, across an estuary, next to a river, within a cow pasture, in a mangrove forest, and within a humid riparian forest. Each of these habitats was sampled for six hours per night, one night a week, for seven weeks between March and May of 1992. Two six hour shifts were employed to fully sample from dusk to dawn, 1800 to 2400 and 2400 to 0600 hrs. A total of 725 bats from 19 different species were trapped, of which only 708 were analyzed for this study. Results revealed that four to five bat species were abundant, with Artibeus jamaicensis demonstrating the greatest relative importance. The remaining species were shown to be rare or uncommon. No significant difference was observed between habitats but a Simpson species diversity index for each habitat produced varying relative diversity percentages which ranged from about 86% to 59%. Feeding guilds were analyzed by habitat and a significant difference was shown between the guilds, but no significant difference was discovered between the habitats. A dominance of frugivores was found in each habitat which enforces the findings ofprevious studies implicating bats as crucial members of the tropical ecosystem due to their seed dispersal and pollination capabilities. Kone, Kourtney, "Food Preferences of an Infant Howler Monkey (Alouatta palliata) during Weaning and the Effects of a Surrogate Mother on the Infant's Food Preferences. Adv. Dr. Monika List, DVM, Zoo Ave. Knox College. 2006. This study is a focal observation of an infant mantled howler monkey's (Alouatta palliata) food preferences during weaning. The effects of a surrogate mother, or the infant's social learning skills, on the infant's food preferences are also assessed. The infant was a young, healthy male approximately 5 months old. He was orphaned and brought to Zoo Ave, a privately funded non profit organization managed by the Nature Restoration Foundation in La Garita, Alajuela. This organization has a successful howler monkey rehabilitation program. The daily observations were divided into 3 periods: Morning, Afternoon 1, and Afternoon 2. The morning periods were purely observational; whereas the afternoon period started with 5 minutes of social learning (i.e. the experimental leaf species was masticated in front of the infant). The rest of the afternoon periods were observational. Kruskal-Wallis tests were used to determine significance. Significant differences were found between the ten tree species, and between Control and Experimental treatments, but not between morning and afternoon observations. A Tukey-Kramer showed where the significant differences were between the ten tree species and the difference between control and experimental treatments. The infant's preferences, in descending order, are as follows: guacimo (Luehea seenannii), jocote (Spondias purpurea), caimito (Chrysophylla brenessii), guaba (Inga sp.), mango (Mangifera indica), ojoche (Clarisia racemosa), guarumo (Cecropia peltata), bamboo (Bambusa sp.), higueron (Ficus sp.), and poro (Erythrina poeppiggiana). A weekly energy budget was also reported and a weight chart showed a positive relationship in the infant's weight throughout the experiment. Packed cell volume values for this individual as well as other previously rehabilitated individuals are included as indicators of their general health condition. Koth, Hatti, "Living Fence Rows and Pseudo-Riparian Corridors and Their Roles in Faunal Movement in Curú, Costa Rica." Adv. Christopher Vaughan. Macalester College. 1993. 8 pp. Two types of habitat corridors, living fence rows and pseudo-riparian corridors, were studied during March and April of 1993 in Curú National Wildlife Refuge on the southeast coast of the Nicoya Peninsula, Puntarenas Province, Costa Rica. Descriptive information was collected on 1858 meters of living fence rows and 3004 meters of pseudo-riparian corridors, including length, width, and tree species. Thirty-two tree species were identified. Daily observations lasting 9-10 hours were conducted for five days on wildlife visiting each of two living fence rows and three pseudo-riparian corridors to quantify use of the corridors by Curú's animals. No significant difference between the wildlife use of the two corridor types appeared in the results of this study, but corridors may still be important to some animal species in Curú. At least twenty-five animal species were observed using corridors during the study: 397 individual birds of 19 different species, 184 individual mammals of 5 different species, and 3 individual reptiles of one species. Shannon-Wiener indices indicated a variation in the floral and faunal diversity of each corridor. The most commonly-seen animal species were the rufous-naped wren (Campylorhynchus rufinucha), which represented 39% of the total individual birds seen; capuchin monkey (Cebus capucinus), (40% of individual mammals sighted); and the variegated squirrel (Sciurus variegatoides), (41% of total individual mammals seen). The results from this study may aid in the future management of the corridors in Curú and may help define the general importance of habitat corridors in conservation biology. Further study is recommended for Curú's corridors. |
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Kotowski, Tanya, "Home Range and Activity Patterns of cacomistle Bassariscus sumichrasti in Braulio Carrillo National Park, Costa Rica". Adv. Christopher Vaughan. Colorado. 1994. 12pp. The ecology of the cacomistle Bassariscus sumichrasti was studied March 7-April 22, 1994 in Braulio Carrillo National Park of Costa Rica using radiotelemetry. The objectives were to determine home range, activity patterns, sleeping site location, and distance moved per night. A total of 392 radiotelemetry locations were taken for two adult females and 2 young males of a known population of Cacomistle in two 6 hour time periods (1800-2400 and 2400-0600). There was no intrasexual home range overlap. The 2 females had larger home ranges than the 2 males. The average home range for all 4 Cacomistles was 24 ha (s.d. 6.7). The Cacomistles were most active from 1800-2000 and from 0200-0400 hours. Activity ceased by 0600 hours. Sleeping sites were within the home range of the individual. Average distances moved nightly wasn't significantly different between sexes or between the entire study group. Lake, Elaina, "Observations on the relationship between jaguars (Panthera onca) and two species of marine turtles: the olive ridley (Lepidochelys olivacea) and the leatherback (Dermochelys coriacea) in Corcovado National Park, Costa Rica during March and April of 1998." Adv. Eduardo Carrillo. Albion. 1998. 13pp. I studied the activity and predation patterns between jaguars (Panthera onca) and two species of marine turtles: the olive ridley (Lepidochelys olivacea) and the leatherback (Dermochelys coriacea) in Corcovado National Park in Costa Rica during March and April. The primary focus of my study was to determine if jaguars maintain a regular predation pattern of the two marine turtles listed above since currently very little is known about their relationship. I identified and recorded the geographic location of jaguar tracks and marine turtle nests each morning with a Global Positioning System, (Garmin 45) to reflect the number of each of the three species present on the beach the previous night. The results from the Spearman´s Rank Correlation test showed that the activity from jaguars in run one who had marine turtles as prey and jaguars from run two who did not have marine turtles available as prey were in perfect disagreement with each other. The findings of the paper support my hypothesis that the presence of marine turtles did influence the activity patterns of jaguars as did the absence of marine turtles. It is still unclear how closely these three species´ activity patterns are associated. Mariner, Peter D., "Movement, Food Habits, and Activity Patterns of a Possible Reforester, Coatimundi (Nasua narica), in a Dry-Tropical Forest." Adv. Chris Vaughan. Univ. of Virginia. 1991. 22pp. With the aid of radio telemetry, coatimundi, Nasua narica, were studied in Santa Rosa National Park, Costa Rica, during March and April, 1991. Coatis moved an average of 1665m daily, foraging for fruits and insects, and traveling to and from waterholes. Coatis were found to be using forest corridors, spending 99.3% of the time in mature forests and only 0.7% in young secondary forests and open pasture. Activity was found to be greatest in the early morning and late afternoon. Diet consisted of fruits and insects dependent on their availability. Resting heights during the day were usually lower than 10m and above 10m at night. A coati nest was also observed and white-faced monkey, Cebus capucinus, predation on coati nestlings was witnessed. McCain, Emil, “Jaguar (Panthera onca) Beach Hunting Activity Patterns, Habitat Preference and Distance Traveled per Night in Relation to the Lunar Cycles and Prey Activity of the Nesting Olive Ridley Marine Turtle (Lepidochelys olivacea) in Corcovado National Park, Costa Rica.” Adv. Eduardo Carrillo and Grace Wong. Colorado. 1999. 22pp. Spacial and temporal patterns of jaguar (Panthera onca) beach hunting tendencies and their relation to the nesting patterns of olive ridley turtle (Lepidochelys olivacea) were studied in Corcovado National Park during March and April of 1999. Data was collected on turtle nesting and jaguar hunting patterns according to location and lunar patterns to observe if any correlation exits. Two habitat types were observed, disturbed (pioneer grasses) and undisturbed (primary forest). Location of activity and hunting distance traveled were recorded every day throughout the lunar phases using a Global Positioning System (G.P.S.). Results indicate that the beach hunting patterns of the jaguar follow a lunar cycle. Total number of jaguar visits to the beach rose during the full moon, but individual averages peaked at the last quarter, then tapered off during the new moon, reaching a low point in the first quarter. No obvious patterns emerged with the turtles, due to infrequent dry season nesting and/or the short study period. However, the increased jaguar presence during the last quarter may indicate that these turtles do indeed follow the same patterns demonstrated by other olive ridley populations on the Pacific Coast of Costa Rica. There was also a slight increase in the jaguar usage of the forested section of beach (1.9 km average) despite the fact the there where significantly fewer turtles nesting in that area as compared with the grass area (1.6 km average). This increased movement in the forested section may indicate habitat preference and be an indicator of forest health. These results will add to the knowledge base and aid in the development of sound management plans for Corcovado and related areas. Timing of human beach use could be based on lunar cycles, and conserving diverse healthy habitat adjacent to nesting beaches could prove essential for further conservation of this rare ecological interaction. Merriam, Jennifer, "A comparison of two white-faced (Cebus capucinus) monkey troops utilizing distinct habitat types in Curú National Wildlife Refuge, Costa Rica." Adv. Chris Vaughan. Colorado. 1991. 16pp. Behavior, movement, diet, and habitat use of two troops of white-faced (Cebus Capucinus) utilizing distinct habitats were compared in Curú National Wildlife Refuge at the end of the dry season during March and April of 1991. The farm troop utilized five cultivated and four unaltered habitats. This troop had 23 individuals. The mountain troop utilized riparian and semi-deciduous habitats. This troop consisted of 14 individuals. It was found that the mountain troop spent significantly more time resting than the farm troop between 1000-1500 hrs. (d.f.=1, f=22.09, p=.009). There was little difference in the daily movement between troops. The farm troop traveled an average of 1.3 km over five days. The mountain troop traveled an average of 1.2 km over five days. Both troops were omnivorous, eating fruits, seeds, other plant parts and insects. The farm troop ate 32 plant species and spent 28% of total time observed eating insects. The mountain troop ate 20 plant species and spent 10% of total observation time eating insects. Though both troops were consistently close to water they were seldom observed drinking. However, the distribution of white-faced monkey troops in Curú indicate that water is a factor in habitat preference. |
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Mintkeski, Tyler, “A Comparison of Wildlife Abundances Between Two Different Protected Areas on the Osa Peninsula, Costa Rica.” Adv. Grace Wong. Colorado. 1999. 20pp. Wildlife abundance indexes were compared in two different protected areas during March and April on the Osa Peninsula, Costa Rica. The two areas compared, Corcovado National Park and TUVA private reserve, have the same ecosystems but are managed differently. Wildlife abundances and diversities were affected by different management of the protected areas. Wildlife abundance indexes were estimated from a total of 263 km of trail censuses counting both sightings and tracks. Corcovado National Park had greater mammal species diversity and a higher total encounter rate. In TUVA reserve ungulate abundances were relatively low probably due to hunting. Large rodent abundances were abnormally high due to the absence of feline predators in the area. Primate troop sizes and densities were similar in both areas. More research is needed to determine exactly what variables are responsible for these differences. Monahan, Brie, "The Role of Bats in Regeneration of Fragmented Tropical Dry Forest in Guanacaste, Costa Rica." Adv. José Manuel Mora. Macalester. 1998. 12pp. The distance to which bats are capable of dispersing seeds in unforested or deforested areas, and whether the ability of these seeds to germinate depends on their distance from the forest, was investigated in Cañas, Guanacaste in Costa Rica in 1998. Bats were captured in fields at measured distances from nearby patches of disturbed or secondary forest. Feces were collected from bats, analyzed for seed content, and samples of the seeds were planted in petri dishes. Percentage of seed-dispersing bats per distance was tested using ANOVA, for differences between the amount of seeds distributed, per distance from the forest. Ninety-nine percent of the 126 bats caught were capable of seed dispersal. Seventy-eight percent were found at the forest edge, showing a significantly higher quantity of bats than the other three distances. In the open fields, no significant difference was found between average number of bats collected per evening per distance from the forest. Of the seeds procured from feces, less than one percent germinated, and germination appeared to be affected by season, suggesting that forest regeneration is taking place at a gradual rate during the dry season, and may increase at other times of the year. This information will be used to plan a future, long-term investigation of the same nature, to be proposed by my advisor. Moore, Daniel, "An Investigation of Twenty Natural Waterholes in Santa Rosa National Park, Costa Rica." Adv. Christopher Vaughan. Macalester College. 1995. 20pp. Twenty natural waterholes were studied in Parque Nacional Santa Rosa, Guanacaste, Costa Rica during the dry season; December, 1994-April, 1995. Four characteristics were studied: a) number of waterholes over time, b) water depth, c) wildlife and d) vegetation. Eight waterholes remained at the end of the dry season and the total depth of all the waterholes decreased from 1,555 cm in January to 894 cm in April. Twenty species of animals were observed at or within ten meters of waterholes. The majority of the waterholes (12) were surrounded by either semi-deciduous or evergreen forest. Twenty-one plant species were identified at waterholes. Muniz, Cynthia, "Animal Utilization of Waterholes, Curú National Wildlife Refuge, Costa Rica." Adv. Christopher Vaughan. Ripon. 1993. 11pp. During the last portion of the dry season months (March 1- April 26, 1993) research was conducted to determine wildlife utilization of waterholes at Curú National Wildlife Refuge, Costa Rica. Two methods, visual field observation recordings, at two waterholes and animal track identification, at seven other waterholes were used. Total number of individual wildlife sightings was 481. The total number of tracks identified was 203. Major results of the animal track identification procedure reveal that water holes Organos and St.Teresa Arriba had higher visitation percentages of endangered and/or game species. Potential seed dispersing species were found to visit water hole St. Teresita abajo #1 Pila, more commonly than any of the other six sites studied. Deer represent the most frequent visitor of all game/endangered and potential seed dispersing species. Field observation method resulted in the sighting of 258 individuals species utilizing water site Jobada and 223 individuals species at water site El Tanque. Most of the visitors at Jobada were mammals whereas at site El Tanque, a higher percentage of bird species were seen. Murphy, Sean, "Observing a Women's Cooperative Iguana iguana Restoration Program in Orocú de Chomes, Puntarenas, Costa Rica: Focusing on Iguana iguana Behavior in Captivity". Adv. Dr. Paul Hanson. Coe College. 2006. This investigation examines the operations of "El Jardín de las Iguanas", an Iguana iguana (green iguana) restoration program established by a women's cooperative in Orocú de Chomes, Puntarenas, Costa Rica. The behaviors of sexually mature green iguanas in captivity were observed and compared to behaviors in the wild. This was achieved by designating locations in a 10mx10m holding pen and then recording individual iguana location and behavior every 15 minutes. The data and observations gathered indicated that captive green iguanas behave similarly to those in the wild, both preferring arboreal habitat and showing territorial behavior. In addition, social and scientific data were gathered to analyze the successes and struggles of the green iguanas, the restoration program, and women in a male dominated society. There was evidence to suggest a need for improvements at the community and association level. Poaching, crime, sufficient program funds, member motivation, and iguana hygiene and care were all concerns. Once these concerns are addressed, there may be potential for ecotourism, the cooperative's ultimate goal. Newby, Chelsea, “Howler Monkey Compatibility: A Comparison of Animals in Rehabilitation with Animals in the Wild.” Adv. Carlos Drews. 2000. 42pp. The overall goal of this project was to assess behavioral differences and similarities between mantled howler monkeys in a rehabilitation program and wild-living mantled howler monkeys as indicators of suitability for release. The study site was a privately owned farm on the northeastern side of the Nicoya peninsula in Costa Rica. Six rehabilitation animals were present for observation the first month, but due to sickness and death, only three individuals successfully lasted into the second month. On average, the rehabilitation monkeys spent 75% of their day time resting, 7% moving, 15% feeding, and 3% socializing. The wild monkeys spent 64% of their time resting, 17% moving, 16% feeding, and 3% socializing. While the wild monkeys were rarely viewed less than 4 m from the ground, the rehabilitation monkeys spent most of their time within 1 m from the ground. The three surviving rehabilitation animals spent more time feeding, socializing, moving, and at higher heights from the ground than the ones that eventually died. The nearest neighbor distances of the population of six rehabilitation animals showed a greater relation to those of the wild than the population of three rehabilitation animals. The methodology of this study has proven to be a valuable contribution towards a protocol to determine the release suitability of rehabilitated mantled howler monkeys. |
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Perron-Burdick, A., “Development of Scarlet Macaw (Ara macao) chicks in the Central Pacific Coastal Region of Costa Rica.” Adv. Christopher S. Vaughan. The Colorado College. 2000. 6pp. Metromorphic development of six wild Scarlet Macaw chicks (Ara Macao) was studied in the Central Pacific Region of Costa Rica (9"46'N, 84"69'W) during the nesting seasons of 1997 and 2000. Growth rates in beak length, wing length, foot length, tail length, neck circumference and weight matched those of other neotropical parrots. Metromorphic measurements grew at a similar rate and fitted Ricklefs?growth curve for normal bird growth. No difference was found in the growth rates between chicks with or without nestmates. Sebastian, Leigh, "White-Faced Monkey Predation on Mango Crops, Curú Wildlife Refuge, Costa Rica." Adv. Chris Vaughan. Vassar. 1993. 11pp. A troop of 19 white-faced monkeys, Cebus capucinus, was followed for thirty days during March and April of 1993 in Curú Wildlife Refuge, Costa Rica. Activity patterns and movement within each habitat were recorded to determine percent time spent within the mango plantations and Cebus feeding on mangos. Throughout March and April, the troop foraged and fed more frequently in the mango habitat than the other habitats (xé2 =478.2 d.f.=5 p>.05). However, the foraging and feeding in the mangos decreased from March to April while increasing in the riparian habitat. The greatest percentage of food consumed were mango fruits (30.9%) and the combined riparian species composed 28.3% of the troop's diet. An average 14.8 exportable mangos (each 1 kilogram or larger, remaining on the tree) were dropped from the tree daily by the monkey troop. The estimated losses of mango production due to monkey damage and consumption would be 562.40 colones per day or 21,933.60 colones over a period of 39 days. This is only a fraction (3.2%) of the costs due to spraying for pesticides, losses due to marketing, etc. Sinning, James A., "Bovine Physical Characteristics, Farm Management Programs, and Geographical Attributes Correlated with a Higher Incidence of Vampire Bat (Desmodus rotundus) Associated Problems on Costa Rican Cattle Farms." Adv. Claudette Mo. Lawrence University. 1993. 40pp. The common vampire bat, Desmodus rotundus, has been one of the primary livestock pests of Latin America as well as the carrier of infectious rabies. While the huge direct economic and production losses caused by the species have been closely monitored, little data have been collected as to the habitat, farm control and management policies, and bovine characteristics that are related to a greater vampire bat incidence and associated problems. The relationships between the exploitation of vampire bat bites by the screw-worm parasite, Cochliomyia hominivorax, and the aforementioned variables were also examined. Interviews were conducted at 98 farms in all of the 7 provinces of Costa Rica and information associated with the vampire bat problem was sought. Over 65% of the cattle on farms investigated were bitten nightly while 22.1% were bitten weekly. The presence of more extensive forests surrounding a given farm was positively correlated with more severe vampire bat problems in 3 of 5 regions investigated. No correlation was found between changes in altitude and vampire bat presence. Farms with >200 heads of cattle were found to have a much greater average number of cattle bitten per night, 81%, than farms with <100 heads of cattle, 42.3%. It was not determined that certain bovine physical characteristics were preferred by the species. A higher incidence of screw-worm infected vampire-made wounds was recorded at farms below 200 meters, with more extensively forested areas, and with greater than 200 heads of cattle. Finally, although appropriate control programs have been initiated slowly, results indicated that in 3 of the 4 relevant regions investigated the use of nets and vampiricida, an anti-coagulant containing vampire bat poison, significantly reduced the incidence of vampire bat bites. Spellman, Stephen R., "The daily activity patterns, diet, habitat usage, and home range of two troops of mantled howler monkeys (Alouatta palliata) in the Nancite Basin, Parque Nacional Santa Rosa, Costa Rica." Adv. Chris Vaughan. Lawrence. 1994. 12pp. Home range, daily traveling, diet, and activity patterns of two troops of mantled howler monkeys (Alouatta palliata) were studied in the Nancite Basin, Parque Nacional Santa Rosa, Costa Rica during the latter part of the dry season (March and April) in 1994. Three daily activities were monitored; resting, feeding and traveling. Resting was the predominant activity totaling 72% and 75% of activity for each troop respectively, peaking between 1000-1400h. Feeding and traveling peaked from 0600-1000h. and 1400-1800h. Feeding equaled 19% and 18% of all activity. Traveling accounted for 9% and 7% of all activity. Troop one utilized an area of 5.5ha. and traveled an average of 494m daily. The second troop utilized an area of 7.1ha. and traveled an average of 536m daily. Troop one consumed 94% young leaves (Lonchocarpus sp. 24% and Mastichodendron capiri 22%), 5% flower buds, and 1% mature leaves (Manilkara chicle 1%). Troop two consumed 48.5% fruit (Licania arborea 47%), 45.5% young leaves (Lonchocarpus sp. 19%), and 6% mature leaves. Spring, Justin, "Management of Dendrobates auratus and Dendrobates pumilio within a former cocoa plantation". Adv. Rafael Ocampo. Colorado College. 1997. 15pp. The management of Dendrobates auratus and Dendrobates pumilio was investigated within the agroecological farm of Bougainvillea S.A. Baseline data was gathered on the influence of supplemented alimentation in the form of fruit flies (Drosophila spp.), mosquitoes (Diptera culicidae spp.), and ants (Formicidae spp.). Bananas were used to attract insects, which in turn, attracted the frogs. Experimental alimentation mounds consisting of cocoa and banana had significantly more frogs than control mounds with only cocoa, in certain treatments. D.pumilio selected the 8m distribution of mounds over the 16m distribution and D.auratus showed a tendency towards selecting the 16m treatment. Baseline data on the species' relationship with rainfall was also taken. Results indicate rainfall is a more important factor for the activity of D.pumilio than D.auratus, and that tires acting as reproductive sites for D.auratus may play a role in decreasing the species' dependency on rain. The results from this study will be utilized in developing a sound management plan for the strawberry poison frog (D.pumilio) and black and green poison frog (D.auratus) populations existing at the agroecological farm. The study took place from March 7th to April 26th, 1997. |
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Timock, Joshua, "A Census of Mammal Populations by Transect in a Mixed Tropical-Wet and Dry Forest in the Punta Leona Private Wildlife Refuge, Costa Rica." Adv. Christopher Vaughan. Lake Forest College. 1996. 27pp. Population sizes of six mammal species were estimated using a variation of the King method during the late dry season (March) of 1996 in the Punta Leona Private Wildlife Refuge, Costa Rica. The white-faced monkey (Cebus capucinus), coati (Nasua narica) and nine-banded armadillo (Dasypus novemcinctus) with 148, 46, and 8 sighted individuals, respectively, demonstrated the largest populations in the refuge. The Central American spider monkey (Ateles geoffroyi), tamandua (Tamandua mexicana), and gray squirrel (Sciurus sp.) were also included in the census. Population densities are calculated, habitat types are described, and habitat use and activity periods are discussed. Advantages and disadvantages of using the King method in tropical habitats are presented and recommendations are made for the maximization of precision and accuracy. Timock, Joshua, "A Note on Interspecific Relations Between a Lone Central American Spider Monkey (Ateles geoffroyi) and a Troop of White-faced Capuchins (Cebus capucinus)." Adv. Christopher Vaughan. Lake Forest College. 1996. 27pp. This is a note on the observation of Interspecific activity. Includes an annotaded anecdote of the observances. Timock, Joshua, "A Wet Season Study of Home Range, Feeding Habits, and Activity and Movement Patterns of a Troop of Costa Rican White-faced Monkeys (Cebus capucinus)." Adv. Christopher Vaughan. Lake Forest College. 1996. 36pp. Home range, diet, and activity and movement patterns of a group of 24 white-faced monkeys (Cebus capucinus) were studied in a Costa Rican mixed tropical-wet and dry forest at the beginning of the wet season (June and July) of 1996. The troop's home range encompassed 0.74 km2 of predominately evergreen forest and troop daily movement averaged 5.2 km ± 0.6. Four daily activities were described: traveling, feeding, socializing, and resting. Feeding, which was associated with traveling, occurred most between 0500-1000 hrs and 1400-1800 hrs. These monkeys were omnivorous, feeding on parts of at least 19 species of plants and 3 species of insects. Frugivory accounted for 60% of total feeding time, while 37.5% was spent on insectivory. Social behavior was strongly correlated with a mid-day resting period from 1000-1400hrs, grooming and play fighting being the most common displays. Trygstad, Heather, "A Comparison of Daily Activity, Diet, Daily Distance Traveled, and Habitat Utilization of Two Troops of Mantled Howler Monkeys (Aloutta palliata) in Curú Wildlife Refuge, Costa Rica." Adv. Chris Vaughan. St. Olaf. 1991. 11pp. Daily activity patterns, diet, daily distance traveled, and habitat utilization of two troops of howler monkeys (Aloutta palliata) were studied in two distinct habitats in Curú Wildlife Refuge, Costa Rica at the end of the dry season (March and April) of 1991. Resting was the major activity for both troops during the study period (54% and 60%), and peaked between 1000-1400 hours. Moving was found to be different between the troops and between months (F=2.23;df=12,3;p<.03), and peaked between 1500-1900 hours feeding peaked between 600-1000 and 1500-1900 hours. Troop one fed on 22 plant species, while troop two fed on 14 plant species. Fruit was the primary food source for both troops. Troop two spent more time eating fruits and young leaves than troop one. Troop one moved an average of 307m. per day and troop two moved an average of 480m. Daily distance traveled was significantly higher in April than in March for both troops (F=10.11;df=4,1;p<.03 and F=32.9;df=4,1;p<.004). Troop one utilized six of eleven habitat types, spending a majority of its time in the semi deciduous forest. Troop two utilized only the semi deciduous forest. Wilding, Amanda R., "Reintroduction of spider monkeys, Ateles geoffroyi, to Curú National Wildlife Refuge." Adv. Chris Vaughan. Grinnell College. 1994. 13pp. Activity pattern, diet, habitat use and behavior of a reintroduced spider monkey (Ateles geoffroyi) troop was studied between March 14 and April 1, 1994, in Curú National Wildlife Refuge, Costa Rica. The study troop consisted of a male and female adult spider monkey reintroduced to the refuge in 1992. Observations of activities, including: resting, feeding and moving, diet and habitat were taken using a variation of the focal animal technique at five minute intervals between 0600 to 1800. The monkeys' primary activity was resting, the most commonly observed activity between 0600-1000 and 1000-1400. Over 50% of the spider monkey's diet was the fruit of Espavel (Anacardium excelsum) and Paulo de Agua (Bravaisia integerrima), during the study. The study animals previous exposure to humans made them very bold and aggressive. Observation was limited because they became increasingly aggressive, including numerous attacks. Although this troop has survived in the wild for two years and reproduced, in the future animals should be carefully selected for reintroduction. |
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Workman, Amy, "Diurnal Activity Patterns of Baird's Tapir (Tapirus bairdii) in Corcovado National Park, Costa Rica". Adv. Chris Vaughan. Monmouth College. 1997. 12pp. Two previously radio-collared Baird's tapirs (Tapirus bairdii) were tracked daily using radiotelemetry on a 6 hr.-basis during a 6 week period in March and April at the Sirena Ranger Station in Corcovado National Park. The focus of the study was to determine diurnal activity patterns (active vs. inactive every hour from sunrise to sunset). Activity was tested for significance according to time of day (split into four 3 hr. 15 min. time intervals), month, and individual tapir. Activity state was significantly dependent upon time interval (P = 2.0660E-5), and tapirs were most active between 0500 - 0815. The tapirs were very close to being significantly more active in April compared to March (P = 0.05714), and Tapir 18 was significantly more inactive than Tapir 23 (P = 0.01038). |
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