All posts by Taylor

Avian Monitoring in Sandhill Habitat in Florida

This proposal comes from the Florida Fish and Wildlife Research Institute and focuses on the conservation of birds in the Sandhill habitat of Florida.  It starts out with an introduction, then leads into the objectives, study population and methods, data management, schedule and deliverables, budget and payments, and then the references.  Most of these sections have sub sections that cover the 6 key steps of a research project (Ex: Study population and methods covers data collection site, and data collection method)

The Sandhill habitat of Florida, and 14 bird species that inhabit it,  are in need of conservation. This is due to invasive species, lack of prescribed fires, development, and converting the land to high density pine plantations. The purpose of this proposal is to collect data on the population of birds in the Sandhill habitat, which can help develop a survey protocol for multiple types of fauna,  and find which areas need management.

This study has already received funding, which allowed this proposal to have a budget on what would be spent. It also details the methods on how they will perform a survey on the birds, and also how they assess the quality of the Sandhill habitat. These methods include exact measurements (such as how far away they will be from a study point to observe) and which tools they will use.

Hummingbird sweetness preferences: taste or viscosity?

Previous studies on hummingbirds have attempted to predict the preferred percentage of sucrose in solution for optimal energy uptake. These values range from 22% to 40%. This study compared the Archilochus alexanderi (black-chinned hummingbird) behavioral response to nectars based on sucrose receptors, sweetness receptors, and by a physical measure of viscosity (thickness/stickiness). The study was conducted in Santa Cruz county, Arizona, and data was collected from ten feeders each with three red, plastic flowers with small “corolla tubes” allowing hummingbird access to the nectar inside. A 20% sucrose solution (average natural flower sucrose concentration) was used as the control nectar, and test nectars were introduced periodically. Test nectar variables included varying levels of sucrose in solution, artificial sweeteners (saccharin, Equal, and aspartame) and carboxy methyl cellulose (used to increase viscosity). The study found that the black-chinned hummingbird did not consume significantly different amounts of 30% sucrose solutions than 20% but that they showed a significant preference for 40% sucrose solution (almost four times that of the control). The study also found that both artificial sweeteners and increased viscosity neither increased nor deterred visitation. In addition, the researchers observed that hummingbirds responded to decreased sucrose concentrations by increasing their sampling behavior at feeders. It was concluded that chemosensory mechanisms, as opposed to physical measures of viscosity, are used by hummingbirds when evaluating and selecting sucrose nectars. The results also support an existing model that predicts that even with added feeding costs associated with higher nectar viscosities, higher sucrose concentrations are preferred by hummingbirds.

Stromberg, M. R., and P. B. Johnsen. 1990. Hummingbird sweetness preferences: taste or viscosity? The Cooper Ornithological Society 92: 606-612.

Do nectar feeders in Andean nature reserves affect flower visitation by hummingbirds?

Hummingbirds are the most important avian pollinators in the Western Hemisphere. They are especially important in highly diverse areas.  Because of this, many plants and hummingbirds have coevolved. Artificial feeders have been introduced in many areas, and the question of whether they affect the relationship between hummingbirds and flora has arose many times. These researchers formed two hypothesis; one was that hummingbirds visit flowers less frequently when feeders and present, and the second was that flower visitation frequencies are not affected due to the increase in population that feeders cause.

The study was conducted in cloud forest reserves of Ecuador. Feeders with a 1:10 sugar water concentration were placed either in near a lodge in the reserve or near the reserve’s entrance. The visitation by hummingbirds to flowers were measured in 4 categories based on their distance away from the feeders, and recorded as visits per hour. The genus of the hummingbirds were also noted, since hummingbird behavior and territoriality varies between species.

There was no statistical difference found between the frequency of hummingbird visitation to flowers and their distance from feeders. These results differ from another study done in Mexico that found that feeders do lower the rates of visitation to plants by hummingbirds. One reason for this study’s findings could be that the territoriality of the hummingbirds was not measured. Another factor could have been that the sugar water was only 1:10, which is a relatively low concentration.

This study concluded that artificial feeders do not tend to decrease flower visitation by hummingbirds, and may in fact facilitate more visitation to flowers at close proximity to the feeders. This should be taken with a grain of salt, because this study was done on 10 species in a particular area, and differences between taxonomic groups of both hummingbirds and flowers could yield different results in other areas. More research should be done on this.

Works cited:
Brockmeyer, T., Schaefer, H.. 2012. Do nectar feeders in Andean nature reserves affect flower visitation by hummingbirds? Basic and Applied Ecology. 13(3), 294-300.
Article sent to me by a previous professor.

Optimal concentrations in nectar feeding

“Optimal concentrations in nectar feeding” is an article by Wonjung Kim, Tristan Gilet, and John Bush. They are affiliated with the mathematical and engineering department at MIT.  The purpose of this study is to see at what concentration of sugar in nectar is ideal for the energy of nectar feeding species, such as hummingbirds. Although higher amounts of sugar offer more energy, the viscosity of the nectar could make it difficult for nectar feeders to carry. Due to nectar feeders needing to avoid predators, the energy levels are important. The study examines the optimal concentration based on the viscosity of the nectar for the performance of nectar feeders.

The sugar concentration of nectar in flowers is higher for the ones that are pollinated by bees (35%), while there is a lower concentration for those that are pollinated by hummingbirds (20-25%).  Because of the different feeding methods of bees and hummingbirds, the viscosity is important when determining the sugar concentration.

Due to the coevolution of flowers and their pollinators, the flowers have different concentrations that are optimal for its pollinators. Bees feed on nectar through a dipping method. Since less nectar is consumed, the flower produces a higher sugar concentration. Hummingbirds feed with a sucking method, consuming more nectar. These flowers that  are pollinated by hummingbirds produce a lower sugar concentration. The lower concentration also provides a lower viscosity, making it easier to fly. This shows that hummingbirds have a preference to lower concentrations. The flower also evolved to produce optimum concentrations. If the nectar was too sweet, it would reduce the amount of flowers that the hummingbirds visit, but too little would not attract them at all.

Works cited:

Kim, W., Gilet,T., Bush, J. 2001. Optimal concentrations in nectar feeding. Proceedings of the National Academy of Sciences. 108(40), 16618–16621, doi: 10.1073/pnas.1108642108
Retrieved from:


Effect of artificial feeders on pollen loads of the hummingbirds of Cerro de la Muerte, Costa Rica

Artificial feeders are commonly used in scientific hummingbird study and for human enjoyment. However, previous to this study very little research had been done on how feeders influence hummingbird behavior and pollination activities, which hold significant ecological importance (especially for specialist hummingbird/flower relationships).  This study examines how the use of feeders and hummingbird behavior, particularly monopolization of a feeder, affected pollen collected by hummingbirds.

Four species of hummingbirds were studied during four sampling periods over two years. The data was collected on Cerro de la Muerte, a region in the Talamanca Mountains of Costa Rica that is dominated by the Oak Forest and Paramo ecosystems. Researchers counted species and number of visits to artificial feeders set out by a local hotel/restaurant (note that a “visit” means when an individual drank from the feeder). They also used mist nets to catch hummingbirds. These individuals were marked and pollen was collected from the beak and throat area using scotch tape.

Feeder usage was dependent on hummingbird species. P. Insignis most frequently monopolized feeder use and was the most frequently recorded visitor to the feeders and in the mist nets. More than 50% of the hummingbirds collected in the nets had little or no pollen on them. Season had a significant impact on pollen collected, but species of hummingbird did not. Pollen from only one species of plant (Centropogon) dominated the pollen collected in this study.

This study shows that artificial feeders have the potential to attract hummingbirds from large distances. This draws them away from flowers, which leads to the potential to decrease of pollination of flowering species in the area. Further, the feeders detract from pollen diversity on hummingbirds, indicating the presence of feeders could reduce plant diversity in the area if some plant species are no longer being pollinated sufficiently by hummingbirds.



Avalos, G., Soto, A., Alfaro, W., (2012). Effect of artificial feeders on pollen loads of the hummingbirds of Cerro de la Muerte, Costa Rica. Revista de Biologia Tropical.

Asian Rhinos (Rhinoceros unicornis) on the run? Impact of tourist visits on one population.

This article by Dale F. Loft and Michael McCoy of University of California, Davis, examines the effects that tourists have on the behavior of asian rhinos. The introduction of this article looks at previous examples of how behavior has been a measure of disturbance relating to tourists. Some of these examples include bald eagles leaving their nests due to increased tourism, and big horn sheep decreasing their foraging behavior when tourists get to close. These cases created a concern for the asian rhinos in Chitwan Park, Nepal since it may lead to some negative behaviors.

Tourism in Chitwan Park is done by riding elephants, with an average group size being 5 to 7 elephants. The rhinos are located in meadows that contain 8meter tall towers which allow for viewing of the rhinos. The grass in the meadows of this area (which are around 4meters tall) are cultivated by locals and then burned which allows for regrowth and higher visibility of the rhinos.  This study observed 14 rhinos in the meadows of Chitwan Park, where a team of researchers recorded the rhino behavior from the towers for 17 days. The behavior was marked every 15 seconds for 5 minutes (total of 20 intervals) before the tourists arrived, while they were there, and after they left. They also recorded how long the tourists were there, and how close they got to the rhinos.

Once the data was compiled and averaged, the results showed a decrease in feeding, and an increase of being alert while the tourists were present. These results were proven to be statistically significant. The proximity of the tourists also affected the behavior, and when tourists were within 7meters of the rhino, the rhino would often leave the meadow.

I feel this study did a good job at answering their research question, and collecting the data needed to do so. The statistically significant results showed the amount of disturbance tourists have on the rhinos, and how some of them are being driven out of their home on the meadow. This article was published in 1993, and since then tourism has nearly doubled. The information collected from this study provides important insight on how to change and manage tourism in areas like this. It also gives readers an idea of how to be conscious of their tourism choices. Often times the close encounters that we want have serious consequences towards the animal. Rhinos depend on feeding throughout most of the day in order to remain healthy, and disruption in their behavior and lifestyle may lead to a decline in their health and success.

Lott, D.F., McCoy, M. (1995)  Asian rhinos Rhinoceros unicornis on the run? Impact of tourist visits on one population. Biological Conservation 73:1, 23-26. DOI: doi:10.1016/0006-3207(95)90053-5

Impacts of ecotourism in Rajiv Gandhi National Park (Nagarhole), Karnataka

The article “Impacts of ecotourism in Rajiv Gandhi National Park (Nagarhole), Karnataka”  by Nichola Anastasia Ramchurjee aims to analyze how ecotourism has effected the wildlife and socio-economic situation of this area. This national park conserves it’s wildlife through organizations like Project Tiger Reserve (which protects their endangered tiger), but also ecotourism to conserve their biodiversity. By preserving biodiversity, it protects more than just the popular few species that receive funding and attention for conservation. To look at how ecotourism has been working in Rajiv Gandhi National Park,  this study surveyed visitors with questionnaires, and park officials with face to face interviews. These questionnaires analyzed the demographics of the tourists, as well as the activities at the park, and their thoughts on the management of the park.

Interviews with officials revealed issues between wildlife and humans. There are tribes within the national park that use methods that are harmful towards the conservation of wildlife, such as burns for agriculture. The park officials are looking for ways to work with the tribes in a way that protects their environment. One of the proposed ideas is relocating the tribes to an area where they will not seriously harm wildlife, nor will wildlife harm them.

The tourists revealed on their questionnaires that they mainly participated in hikes and viewing nature, while also ranking ‘learning about nature’ as a very important part of their experience. Tourists also responded that they were concerned with the litter, vegetation damage, and soil erosion in the park. By analyzing the results of the questionnaire, it showed that the park needs to put a larger effort into creating educational programs or displays.

The article concluded that the park officials and managers need to work closer with other people to conserve biodiversity. By working closer with the local tribes and improving ecotourism educational efforts,  Rajiv Gandhi National Park can promote a sustainable management plan that benefits the people and their environment.


Ramchurjee, Nichola (2013). Impacts of ecotourism in Rajiv Gandhi National Park (Nagarhole), Karnataka. Environment, Development and Sustainability 15, (1),1517-1525. doi: