Monteverde Institute: Tropical Ecology and Conservation

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  Wing color and mating preferences of Heliconius sara, May 2007

  Emily Loew

  Convergence in aposematic coloration of chemically-protected butterflies, or Müllerian Mimicry, improves advertisement of unpalatability to predators. Heliconius sara (Heliconiinae) has two races in Costa Rica, each matching a different Müllerian model, one with and the other without a yellow stripe on the bottom edge of the hindwing. Color switching in Heliconius spp. is common but may involve a conflict between natural selection for convergence to models and sexual selection for maintenance of the original color pattern. Here, I manipulate the color pattern of H. sara to determine the degree to which sexual selection constrains color pattern switching. This study was conducted in the Monteverde Butterfly Garden in Monteverde, Costa Rica and looked at mating behaviors of 75 Atlantic race H. sara, which have uniformly black hindwings. Newly- emerged individuals were painted with a stripe of yellow or black on the bottom edge of the hindwing. Mating behavior was observed over 11 days. Males did not show a preference for female wing color for approach, chasing, courtship or rejection (Chi- squared test, df = 3, p < 0.05). However, females seemed to prefer black painted males for approach, chasing and courtship (Chi-squared test, df = 3, p < 0.05). If black is the ancestral condition, these results suggest that color pattern switching in H. sara is constrained by female mate choice.

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  Assessing demand for organic produce in the Monteverde area, December 2006

  Jacki Walczak

  Small-scale, local and organic agriculture is beneficial to communities environmentally, socially, and economically. In this study, consumer preference for organic produce, in particular lettuce, oranges and plantains, was examined in the community of Monteverde and surrounding areas. Five local stores were surveyed, all of which were unique in their location, size, and clientele. There was a significant difference between the organic and non-organic lettuce that consumers purchased at equal prices (Sign Test, n = 9, p < 0.05) and with a ten percent increase on organic lettuce (Sign Test, n = 10, p < 0.05). The difference was not significant for either organic and non-organic oranges (Sign Test, n=2, p>0.05) or plantains (Sign Test, n = 2, p > 0.05) either equal prices, or with a ten percent increase on the organic oranges (Sign Test, n = 2, p > 0.05) and plantains (Sign Test, n = 2, p > 0.05). These data suggest that there is a demand in the area for organic vegetables that cannot easily be grown in local gardens. Oranges and plantains are organically grown by families, so there is no need to buy it from a store. Increased communication between the local farmers, vendors and consumers could help to establish a healthy local market for specific types of produce, creating a more self-sufficient and autonomous Monteverde. Organic production will improve soil integrity of the farmers’ land, as well as yield a supply of healthier produce choices for the entire community.

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  Behavioral changes of the Slate-throated Redstart (Myioborus miniatus) and the Collared Redstart (Myioborus toquatus) along an altitudinal gradient in the Monteverde Cloud Forest Preserve, December 2006

  Emma Gabrielsson

  Climate change has been found to affect the distribution of bird species in Monteverde, Costa Rica (Holmes 2000). In this study, the Slate-throated Redstart (Myioborus miniatus) and the Collared Redstart (Myioborus toquatus) were observed in the Monteverde Cloud Forest Preserve. Both altitudinal distribution and behavior were observed for both species. It was found that the Slate-throated Redstart has moved up in altitude. Further, observations for both species were compared using a chi square test, and there were significant differences between the two species, and also within the same species. This study shows that climate change is possibly responsible for the migration up hill, which in turn may impact the future behavior of bird species, competition and may cause extinction.

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  Blood parasite infection in mice from cloud forest and nearby disturbed habitats, December 2006

  Jesse A. Blumenstock

  Conversion of habitat by humans is pervasive, increasing, and the root of serious environmental problems. This study was performed to find differences in blood parasite infections of host mice in neotropical cloud forest versus nearby disturbed habitat. In Monteverde, Costa Rica, mice were trapped and examined for blood parasite species richness and abundance in primary forest and disturbed areas near houses. Twenty-eight mice were captured: 15 from the forest and 13 from the disturbed habitats. Eighty-six percent of these mice were of the species Peromyscus nudipes. There was no significant difference of parasite species richness between mice from the forest habitat (mean = 2.818 ± 1.25; N = 11) and disturbed habitat (mean = 3.25 ± 0.75; N = 12)(Mann-Whitney U = 54.5; P > 0.05) or of parasite abundance between the forest habitat (mean = 8.36 ± 5.12; N = 11) and disturbed habitat (mean = 10.33 ± 5.02; N = 12) (Mann-Whitney U = 57.0; P > 0.05). Transference between the habitats may be frequent, causing similarities in parasite infection rates and types between the populations. Peromyscus nudipes is a “weedy” species and possibly does not discern between the different areas, resulting in this transference.

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  Changes in bird species distribution in four altitudinal zones in Monteverde, Costa Rica, December 2006

  Grant Connette

  The impact of climate change on ecosystems has been demonstrated by studies of upper elevation amphibians (Pounds 1997). In spite of this, the degree to which climate change affects birds is not as clear. Two previous studies have found the upward movement of many species of birds in the Monteverde area (Donnelly 1998, Palm 2003). I surveyed birds in four altitudinal zones on the less studied Atlantic slope of the Monteverde Cloud Forest Preserve and compared my findings to the bird distributions reported by Michael Fogden in 1993. I found significant upward movement of bird species (sign test, p < 0.05) as well as a general decline in the abundances of certain bird species (x2 = 27.65, df = 3, p < 0.001). The majority of these declines are probably linked to the reforestation of the Peñas Blancas valley but climate change is likely responsible for the upslope movement and increased abundance of higher elevation birds.

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  Determination of the optimal pollinator of Stachytarpheta jamaicensis (Verbenaceae) based on nectar production throughout the day, December 2006

  Stephanie Siemek

  Stachytarpheta jamaicensis has been found to have various visitors but its actual pollinator is unknown. I Collected nectar from 22 individual plants during various times of the day and I determined that S. jamaicensis produces most nectar during 6:00 am and 6:00 pm. Observation of the visitors were recorded for each hour and ten flowers were collected for each potential pollinator after they were observed obtaining nectar from the flowers. Nectar production was found to be significantly abundant early morning and late afternoon, this suggests that S. jamaicensis produces nectar for hummingbirds and moths since this is when they are most active. Flowers used in order to determine how much pollen remained on the stamen after visitation by each potential pollinator. Observation of activity and statistical analysis showed that butterflies were the most abundant in visiting, but pollen amounts on the stamens did not show any significance for any of the species. Due to lack of sufficient data on moths, the amount of pollen left over after visitation of these species was unable to be determined.

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  Determining avian vulnerability to ectoparasites using morphological and natural history traits, December 2006

  Lili K. Prahl

  Avian parasitism is the cause of many negative effects on host organisms including decreased fitness through reproductive failure and reduced health. There is increasing research being done to assess the characteristics of bird host morphology and natural history that influence the presence and abundance of ectoparasites on these hosts. This study attempts to create an index of sensitivity that can be used for different bird species in order to determine their expected vulnerability to ectoparasites. This index uses five parameters: bird weight and bill length, both determined by field work, as well as bird behavior, habitat, and population density. This index was then compared to data collected that determined the presence of mites in seven different bird species of Monteverde, Costa Rica. The index proved to be accurate for the most extreme cases but failed to accurately predict the presence of ectoparasites in bird species in the middle range of the index.

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  Discrimination of aposematic and novel prey by mature Sceloporus malachiticus, December 2006

  Jeff Masterson

  Prey use a variety of defenses against predators in order to avoid predation and often use warning coloration known as aposematism to advertise unpalatability to predators. Predators have accordingly evolved defenses against possibly unpalatable prey by being selective, and avoiding aposematically colored prey items. Some predators are more selective, avoiding anything appearing novel (neophobia), thus lowering the risk of unprofitable foraging by restricting their diet to familiar items. Previous studies have shown that neonatal Sceloporus malachiticus will innately avoid aposematic prey. In this experiment I examined any potential changes in prey selection concerning aposematic or novel prey items in S. malachiticus in Monteverde, Costa Rica. I used paint pens to create three different color patterns on crickets; drab, aposematic, and novel. I fed nine S. malachiticus these different treatments in random order over the course of six trials. I found that the lizards showed no apparent preference for any color type (Friedman test, p = 0.0970, n = 9), indicating a loss of dietary conservatism as mature adults.

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  Forest proximity, avian diversity and insect herbivory in shade grown coffee, December 2006

  Frannie Peterson

  Conversion of forest to agricultural plots, plantations, and pastureland is one of the top two reasons for the unprecedented rate of tropical forest destruction. Coffee, in terms of area, is the most important crop in Costa Rica and continues to threaten remaining forest (Lean 1990). This study examined how proximity of coffee plantations to forest stands affects avian diversity, and the role of avian insectivores on coffee herbivory. Avian diversity was studied at two coffee plantations, one near and one far from the forest. Avian diversity was significantly higher in the near-forest coffee plantation than in the far forest. However, there was no significant difference in herbivory or insectivory between the two sites. These results suggest that forest stands are important to the conservation of avian diversity in coffee plantations.

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  Fruit production frequency as an indication of self-pollination in Lepanthes eximia (Orchidaceae: Pleurothallidinae) in Monteverde, Costa Rica, December 2006

  Kathryn A. Lulling

  Most orchids are capable of self-pollination, but outcrossing promotes the variation in flower structure and the specificity of pollination mechanisms prevalent in orchids. For this reason there are many elaborate pollination mechanisms involving specific pollinators. Highly specific mechanisms ensure efficient pollination, yet low fruit production is common in orchids and in the genus Lepanthes. An exception to this trend is Lepanthes eximia, which has a relatively high fruit set. This may indicate that L. eximia does not depend on rare pollination events, but self-pollinates, accepting low genetic variability in order to increase its number of offspring. Two groups of L. eximia, one exposed to potential pollinators and one covered with mesh bonnets, were observed for differences in fruit production in the orchid garden of Dr. Karen Masters in Monteverde, Costa Rica to determine if L.eximia self-pollinates. Comparisons in morphological variation of L. eximia and L. pygmaea, both exposed to potential pollinators, were made to examine the differences in variance between inbred and outbred species. Lepanthes eximia was found to be capable of self-pollination, but no significant difference in the variability of morphological traits of inbred and outbred species of Lepanthes exists.

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  Hymenoptera diversity and abundance in fragmented and continuous forest in San Luis, Costa Rica, December 2006

  Katie MacDiarmid

  Fragmentation of forest habitats can have a negative impact on the diversity of many species. When fragmentation impacts pollination, it can result in major changes to the composition of forest plant communities as well as a reduction in fruit production for nearby agriculture. I studied Hymenoptera diversity in a four hectare fragment and a continuous forest using Euglossine traps as well as a mixture of honey and water to attract Hymenoptera species. Hymenoptera diversity did not differ significantly between the two habitats but abundance of Hymenoptera, Euglossine, and Apidae were all significantly greater in the continuous forest site. This indicates that continuous forest supports a larger, more stable population of Hymenoptera species, thereby supplying steadier pollination services to the forest and nearby farms.

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  Integration of art and environmental education: the Centro de Educación Creativa in Monteverde, Costa Rica, December 2006

  Veronica Harried

  Population growth and deforestation are negatively affecting biodiversity in the Tropics, necessitating environmental education for local populations. Arts education increases the ability to comprehend complex information, enhance creativity and provide problem solving skills (Longley 1999, Siegesmund 1998). Together, environmental education and Arts education can enhance ecological processes and conservation themes in students’ minds so they are retained well into their adulthood. This increases the likelihood that these individuals will make environmentally informed decisions throughout their lives (Gurevitz 2000). In this project, I incorporate current Arts curriculum guidelines from the United States into the Costa Rican environmental curriculum used at the Centro de Educatión Creativa in Monteverde, Costa Rica. I create sample activities incorporating visual arts, music and theater into each of 12 curriculum themes. Evaluations by Amy Cherwin, the Curriculum Director at the CEC, and the first and second grade teachers there suggested the updated curriculum guidelines I extended were both useful and relevant to their classroom activities. According to evaluations, the sample activities I created were generally easy to understand and useful.

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  Maternal defensive behavior of Umbonia ataliba treehoppers, December 2006

  Sarah Anvik

  A population of Umbonia ataliba (Homoptera: Membracidae) located between 1300 and 1500 m in Monteverde, Costa Rica was studied from October to November 2006. The maternal defensive behavior exhibited by these subsocial insects toward nymphs of different developmental stages was experimentally investigated. The purpose of my study was to determine how the defensive behavior changed from eggs to adults and in response to two different predator types. I attached dead wasps to long wooden sticks and then simulated predator approaches toward family groups of eggs, second instar and fourth instars nymphs. I found that the defensive behavior by females guarding nymphs of different ages differed from random in type and frequency. I determined that female parents with second instars were the most aggressive, and that the most common behavior type among all groups proved to be kicking. In regards to the behavior changes exhibited against predator types, females were generally more aggressive when approached with the black wasp, but there was no significant change in the frequency of behaviors.

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  Medicinal plant use and knowledge for Monteverde residents based on age and education, December 2006

  Cassandra Gurgiolo

  Approximately 80% of the world population relies on medicinal plants from the forest, home gardens, or market as a primary form of healthcare (Alcorn 1995). However, increased development and deforestation in recent years may be compromising the practice of natural medicine among the inhabitants of many developing countries. Interviews with 33 residents of Monteverde, Cost Rica examine both the current level of knowledge concerning natural medicine and its practice based upon age and educational level. Statistically significant positive linear relationships were found between both utilization and knowledge of medicinal plants and age. Knowledge and utilization of medicinal plants decreased weakly with increasing educational level; however age may be a confounding variable, as education was correlated with age. Despite the lower number of natural treatments cited by the youngest participants, the practice of natural medicine is indeed still prevalent among residents of Monteverde, demonstrated by the average number of ailments for which participants used medicinal plants, 11 out of 16. As the species of plants cited are mostly exotics or garden-variety natives, the results of this study do not have strong implications for conservation. Nevertheless, considering the lack of affordability of pharmaceutical products, it is fortunate that medicinal plant knowledge has survived in this community.

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  Microclimate effects on cyphellae density in Sticta lichens, December 2006

  Aidée Casillas

  The genus Sticta is a dominant lichen in tropical montane rainforest environments that is unique in possessing cyphellae, i.e. depressed pores involved in gas exchange, on the undersides of thalli. Microclimatic parameters such as relative humidity, canopy density and temperature were measured in relation to cyphellae density and colony size of S. filix in the Monteverde Cloud Forest. Significant correlations were found relating canopy density to cyphellae density (R2 = 0.200, p = 0.0007, n = 54), (R2 = 0.213, p = 0.0016, n = 44), colony size to temperature (R2 = 0.239, p = 0.0002, n = 54), (R2 = 0.592, p =. <0.0001, n = 20), as well as colony size to humidity (R2 = 0.301, p = <0.0001, n = 54), (R2 = 0.567, p = 0.0092, n = 20), (R2 = 0.272, p = 0.0016, n = 34) . Significant differences were shown between non-reproductive individuals of edge and interior microhabitats and temperature (t = -9.024, DF = 42, p = <0. 0001). Further analyses showed significant differences between non-reproductive and reproductive individuals and temperature (U = 67.50, p= 0.0472, n = 34) as well as canopy density (U = 67.00, p = 0.0452, n = 34); as well as a significant difference between interior and edge individuals and canopy size (U = 217.00, p = 0.0276, n = 54).

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  Microorganism species richness and diversity in elfin forest bryophytes, December 2006

  Andrew Miller

  The elfin cloud forest in Monteverde, Costa Rica is an area with a species rich bryophyte community that harbors an unexplored community of microscopic organisms. I examined two morphospecies of bryophytes to compare their species richness of microorganisms living in the water the bryophyte holds. The factors that I examined that may affect microorganism’s species richness are pH and structural differences between the bryophyte morphospecies. Bryophyte water samples were collected, pH was measured, and protozoan species were counted and viewed under a compound microscope. Even though there were visible differences in structural complexity between moss morphospecies (longer shoot lengths and thicker patches) there were non-significant differences between the average species richness per sample (Mann-Whitney U test, U = 78.5; P = 0.16). I found a significantly higher diversity of microorganisms in one moss morphospecies (T-test, t-value = 3.62, P < 0.05). The moss morphospecies with shorter shoot lengths had one unique microorganism and higher average (but not significant) species richness per mL of water than the second morphospecies (T-test, t-value = -1.5; P = 0.14). This is due to one moss morphospecies holding much more soil and detritus in its samples and therefore microorganisms living in the attached soil were also counted.

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  Mycorrhizae concentration and fitness of canopy orchids in the cloud forest of Monteverde, Costa Rica, December 2006

  You-Young Clover Lee

  Orchids require the presence of mycorrhizal fungi in their root systems to germinate, but the importance of fungi after germination is the focus of this investigation. The purpose of this study was to examine whether increasing the coverage of mycorrhizal fungi increases overall fitness and productivity of individual orchids. Orchids of two species Masdevalia chasei and Trichosalpinx memor were collected from cloud forest tree canopies and their fitness and infection levels were estimated. The fitness of each individual was measured here as number of leaves, number of inflorescences, length of longest leaf, length of longest stem. The percent coverage of mycorrhizae was determined by the amount of area on a cross section of a root sample covered by fungi divided by the total surface area of each cross section. The results showed that the amount of mycorrhizal fungi is not correlated with orchid fitness or productivity. There was no significant difference between the mean percent coverage between the two orchid species (t-test, t = 0.08, p = 0.94, df = 43). The importance of mycorrhizal fungi to epiphytic orchids in the cloud forests of Monteverde may be important and possibly even critical, but not precisely correlated with fitness.

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  Native garden design for the Monteverde Biological Station, December 2006

  Katie Korus

  This is a plan for a native garden at the Monteverde Biological Station designed in November of 2006. The garden has been designed to be used as a learning tool for the students at the Station and once developed will be aesthetically pleasing and attract native pollinators. The design includes sections of (1) light gap specialist plants (2) epiphyte families (3) plants that are examples of evolutionary mimicry to attract pollinators (4) common butterfly or hummingbird pollinated plants and (5) common understory plants. Plants for the garden were obtained from the Bajo de Tigre native plant nursery in Monteverde. Thus far, the mimicry section has been planted and the epiphyte section has been cleared and prepared, and native families missing from the section were introduced. Included here are (1) a blueprint for the continued planting of the garden and (2) color plates with pictures and botanical information about the plants to be incorporated in the garden.

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  Nutrient availability and protist abundance in cloud forest Bromeliads, December 2006

  Cierra Y. Allen

  Protists are microscopic organisms which play a vital role in nutrient degradation in tank bromeliads (Carrias et al. 2001). Their communities provide good subjects of study for the effects of nutrient availability in an ecosystem. One hypothesis says that the number of individuals that an ecosystem harbors is determined by the total energy that enters. This study tested the prediction that there will be a relationship between nutrient availability and abundance of protists in tank bromeliads. Data were collected among 25 bromeliads located within the Monteverde Cloud forest, Cerro Plano, Costa Rica and the following parameters were estimated: the number of protists and nutrient resources (canopy density, water volume, tank diameter, and detritus dry weight). Regressions analyses showed there were only significance between detritus weight by water volume and number of detritivores by number of photosynthetic protists. This study shows that none of the resources tested were significant in determining protist abundance in bromeliad tank communities, however, further study is needed.

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  Oviposition preference and larval growth rates of Caligo memnon (Nymphalidae: Brassolinae), December 2006

  Emily Webb

  Caligo memnon caterpillars specialize on plants in three families, Heliconiaceae, Marantaceae, and Musaceea. These families are in the Order Zingiberales. Heliconiaceae and Marantaceae are native to the Neotropics, but Musaceae is an introduced family. I studied oviposition preference and larval performance of C. memnon on four host plants: Heliconia latispatha and Heliconia stricta (Heliconiacea), Calathea insignis (Marantaceae), and Musa acuminata (Musacea). Results showed that preferred host plants for oviposition did not correspond to the host plant that provided the fastest growth rate for caterpillars. Females preferred to oviposit on M. acuminata even though larval growth was lowest on this species, though not significantly. It may be that C. memnon is exhibiting maladaptive oviposition behavior and the introduced M. acuminata may be confusing the coevolved mechanisms for host plant choice.

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  Patch fidelity behavior in coexisting damselflies: Hetaerina cruentata (Odonata: Calopterygidae) and Argia extranea (Odonata: Coenagrionidae), December 2006

  Anna C. Peterson

  Patch fidelity in coexisting territorial damselfly species, Hetaerina cruentata and Argia extranea was studied to determine if these species displayed differing territorial behavior, which may be one mechanism for niche differentiation of these species. Data such as light amount and proximity to water of the patch sites were gathered to provide information about territorial preferences of these two species. No significant relationships between patch fidelity and patch characteristics were found. A significant difference was seen between the patch fidelity of the two species, implicating territory as a possible niche differentiating mechanism. Possible explanations for the variation in patch fidelity behavior between the species include: genetic differences between the two species, differences in learning abilities in relation to life span, and differing impacts of population dynamics on H. cruentata and A. extranea.

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  Soil Organic Matter (SOM) in agroecosystems and intact cloud forest in the Monteverde area, Costa Rica, December 2006

  J. T. Metten

  Properly managed agroecosystems have great potential for sequestering carbon as Soil Organic Matter (SOM) (Brown et al. 2002; Lal 2005). I measured % SOM, Bulk Density, Total SOM, and Root Biomass in two agroecosystems, forest fragment, and intact cloud forest in Cañitas and Monteverde, Costa Rica. These data were analyzed to see if agroecosystems and forests differ in carbon sequestering ability. I found significant differences in % SOM and Bulk Densities between agroecosystems but when Total SOM was calculated, results were not significant. Analysis on Total SOM alone suggests that agroecosystems and forest in Monteverde have an equal ability to sequester SOM. However, root biomass may have an important role. When significant data from Average Root Biomass was added to Total SOM to calculate an estimate of belowground carbon data became significant. Intact forest was significantly higher in combined Root Biomass and Total SOM than the agroecosystems and forest fragment. Though the data suggests that agroecosystems in Monteverde are capable of sequestering considerable amounts of Total SOM, including Root Biomass illustrates the importance of conserving intact forest to maximize carbon sequestration.

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  Species composition of bats (Chiroptera) in different land- use mosaics, December 2006

  Samantha Carter

  Bats are an abundant and diverse group of species that can be used as indicators of habitat disturbance and to test the effects of land-use mosaics on an ecosystem. For 11 nights I used mist-nets to sample the bat assemblages in pastures, forest fragments, banana fields and coffee fields on the Finca Santamaría in Cañitas, Monteverde, Costa Rica. The differences between the land-use areas were not significant in the abundance of bats, species richness, species diversity or trophic diversity. However the species that were found, such as Glossaphaga commissarisi and Sturnia ludovici could be considered indicators of disturbed habitats suggesting the entire area is degraded to a point that only generalist species persist.

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  Territorial response of Rufous-and-white Wrens (Thryothorus rufalbus) to neighbor/stranger conspecific playbacks, December 2006

  Kaitlin Dunn

  I tested the Rufous-and-white Wren (T. rufalbus) for discrimination between the songs of neighbor and stranger conspecifics. I found significant differences in behavioral responses between the song playbacks of neighboring and unfamiliar conspecifics in seventeen pairs of the Rufous-and-white Wren. Birds sang for longer periods and sang more songs in response to playbacks of strangers. However, the amount that they approached the playback source did not differ between the song types. These results suggest that Rufous-and-white wrens recognize the songs of neighbors and identify the individuals as less threatening than strangers. This diminished response may be an adaptive strategy to reduce the energy spent in territory defense. Wrens do not differentially approach the song source because this behavior is not a primary territorial defense strategy.