Behaviour topics

HO107 Angrier in the middle? Does territorial aggression differ with elevation and competitors in tropical understorey passerines?

(start dates 07 June, 14 June or 21 June; need to complete HO001)

Range patterns of species on tropical mountains are generally typified by narrow elevational distributions, particularly in birds, but little consensus as to the exact causes of these distributions has been reached. Physiological stress, ecotones (e.g. habitat and temperature) and aggression between related species may restrict these distributions, but it remains unknown as to whether birds are subject to greater territorial pressures within or at the edges of these elevational ranges as a result. Several species that are suitably abundant and of which the elevational ranges are sufficiently understood, offering ideal subjects for which to study aspects of territoriality, are present in Cusuco National Park, Honduras (e.g. black-headed nightingale-thrush, Catharus mexicanus, and grey-breasted wood wren, Henicorhina leucophrys). A range of projects are possible using playback experiments to assess differences in intraspecific aggression with elevation and local climate regimes and whether interspecific differences occur in range overlaps. This project will complement work currently being undertaken on the role of physiology and aggression in defining the elevational distributions of tropical cloud forest species, focusing on Catharus nightingale thrushes.

Extended Project Summary


HO111 Ecology and behaviour of bats in tropical cloud forests, Honduras

(start dates 07 June, 14 June or 21 June; need to complete HO001)

This project has a waiting list

Cusuco National Park has a fantastic diversity of bats that have adapted to the incredibly complex landscape with huge variation in elevation, temperature and rainfall resulting in a wide range of habitats. Bats in the park have been monitored between June and August each year since 2006 using mist net surveys. Over 50 species of bats have been captured at Cusuco including insectivores, nectarivores, frugivores, carnivores and sanguivores. In addition to abiotic data on lunar phase, precipitation and temperature, habitat measurements are also available. Potential ecology projects include examining the effects of abiotic variables, prey abundance and/or habitat type on bat abundance or demography. Studies could also examine how ecological variables contribute to annual variation in bat abundance or diversity using Opwall’s historical data. The abundance and diversity of bats in Cusuco permits comparisons within or across species or guilds. In addition to mist netting, acoustic surveys using ultrasonic recording equipment are now being implemented. This permits projects on vocal behaviour, such as examining echolocation or social vocalisations in individual species, developing species identification using echolocation signals, or comparing mist net and acoustic survey data for species presence and abundance.

Extended Project Summary

 

HO115 The dynamics of mutualistic cleaning interactions on Caribbean coral reefs

(start dates 14 June, 21 June or 28 June; need to be dive trained and to have completed the Caribbean reef ecology course)

On coral reefs, the cleaning behaviour of certain species represents an important interspecific and mutualistic relationship that provides a vital ecological service to the wider reef fish community. In the Caribbean, cleaning is performed by both fish (primarily gobies of the genus Elacatinus) and invertebrates (primarily the Pederson cleaner shrimp, Ancylomenes pedersoni). Cleaner species occupy cleaning stations that are sought by client fish who perform set behaviours in order to initiate cleaning. The dynamics of these interactions are complex, and span the taxonomic spectrum of the reef fish community, with Pederson cleaner shrimp alone known to service over 20 families of fish. After mapping the cleaning stations present at a site, students will use remote video observations to explore patterns in cleaning behaviour involving shrimp, gobies or both. Projects could focus on drivers of clientele composition, or how cleaning frequency and duration varies between client species. Alternatively, projects could build on recent research demonstrating the impact of diver presence on the provision of cleaning behaviour through a combination of in water diver observations and remote videography.

Extended Project Summary

 

HO118 Physiology and behaviour of the long-spined sea urchin, a keystone Caribbean coral reef herbivore

(start dates 14 June, 21 June or 28 June; this project is predominantly laboratory-based but can also include a diving element; need to complete Caribbean reef ecology course and dive training if required)

This project has a waiting list

The long-spined sea urchin (Diadema antillarum), is responsible for the maintenance of coral reef health throughout the Caribbean. However, in the early 1980s a region wide epidemic reduced their populations by an average of 98%, which stimulated the widespread macroalgal phase-shifts that currently plague the Caribbean. Despite the fact that restoration of D. antillarum is widely believed to be a conservation priority we know surprisingly little about their physiology and behaviour. The aim of this project is therefore to explore the innate responses of this keystone species to numerous external environmental and physical factors, such as food and habitat availability, rising sea surface temperatures and ocean acidification, which may affect the success of targeted conservation efforts. These questions will be answered through a series of laboratory manipulations on urchin specimens collected from nearby reefs.

Extended Project Summary


HO119 The behaviour of invasive lionfish on Caribbean reefs

(start dates 14 June, 21 June or 28 June; this project is predominantly laboratory-based but can also include a diving element; need to complete Caribbean reef ecology course and dive training if required)

This project has a waiting list

The invasion of lionfish in the Caribbean has developed into one of the greatest threats to the survival of the region’s coral reefs thanks to the devastating effect they have on native fish populations. Research has naturally focused on mapping the spread of lionfish, quantifying their ecological impacts, and exploring management interventions to reduce their numbers. However, improving our understanding of the behaviour of this species on non-native reefs is of particular interest to better grasp the underlying success of their invasion. This project will assess lionfish behaviour both on the reefs and in a small laboratory, where individuals will be captured and processed. Particular focuses of this work could include prey selectivity, and habitat preferences to investigate the cryptic nature of this species, and data can be linked to ecological characteristics of the reef itself.

Extended Project Summary


HO120 Behaviour and feeding ecology of Caribbean reef herbivores

(start dates 14 June, 21 June or 28 June; need to be dive trained and to have completed the Caribbean reef ecology course)

Coral reefs are traditionally found in nutrient-poor (oligotrophic) water. Hard corals are very successful nutrient recyclers, which allows them to thrive in these conditions despite their extremely slow growth rates. Faster growing macroalgae are at a competitive disadvantage under these conditions, whilst any significant growth that does occur is kept in check by a large community of herbivorous fish and invertebrates. However, in recent decades organic pollution along tropical coastlines has caused widespread nutrient loading, while overfishing and other impacts has greatly reduced herbivore populations. As a result, macroalgae has begun to take over reefs in what is known as a phase shift, compromising the long-term health and resilience of these important ecosystems. This project aims to explore patterns in feeding behaviour and efficiency between different Caribbean herbivores, using a combination of in situ observations via scuba diving and remote videography. Data will focus on feeding preferences between different types and densities of macroalgae, and on calculating feeding rates using artificial algal plates placed on the reef. Students will also conduct surveys of the herbivore communities present to gauge overall grazing pressure at study sites.

Extended Project Summary


IN122 Functional ecology of coral reefs

(start dates 20 June, 27 June or 04 July; need to have completed reef survey techniques course and be dive trained if incorporating a diving element into the research)

Coral reefs exist within a dynamic equilibrium, their form and function being driven by environmental conditions and interactions between the species that inhabit them. Dominance of reef building corals is diminishing across the world, whilst other taxa such as algae start to dominate. The shift from coral to algal dominance has been well documented in the Caribbean and appears common place. However, within the mega biodiverse reefs of the Wakatobi there has been no such shift. One hypothesis is that the levels of algal removal by herbivorous fish species reduce the competitive ability of algae preventing a regime change. However, as many species of larger fish herbivores are exploited it is possible that algae will increase in abundance, start to dominate benthic systems and bring about a decrease in reef biodiversity. There is thus an urgent need to quantify the amount of herbivory and to explore the relationship between herbivore biomass, rates of herbivory and habitat quality. Levels of herbivory can be estimated through examination of the biomass of herbivores present on reefs coupled with studies of feeding behaviour. It remains unknown whether different fish species exploit the same algal species and therefore it is quite possible that it is the assemblage of herbivores present that is key rather than the overall biomass of this functional group combined. Dissertations working in this area will help managers to identify the key species and critical biomass of herbivores needed to ensure reef building corals remain competitive and continue to underpin the extreme globally important biodiversity of reefs within the coral triangle.

Extended Project Summary


IN125 Behavioural adaptations of dwarf cuttlefish, Septa bandensis

(start dates 20 June, 27 June or 04 July)

As a group, cephalopods display a high level of nervous integration resulting in complex behavioural responses and social interactions that rival those seen in higher vertebrates. The Wakatobi National Park is home to at least 30 cephalopod species, many of which can be found inhabiting reef and reef-associated habitats. The dwarf cuttlefish (Sepia bandensis) is the most abundant cephalopod species found in the park, occurring in large numbers near rocky shorelines, on coral rubble, in seagrass meadows and at mangrove margins. While the species has some minor commercial value in local artisanal markets, its major importance lies in their ability to shape habitat ecology by indiscriminately preying on large numbers of small to medium sized crustaceans. In spite of their ecological importance, little is known about the feeding behaviour or social interactions in this species. The primary objective of dissertation projects could include aspects of feeding behaviour, effects of competition, and social interactions between individuals of different gender and/or size. Other studies may be considered but require approval of the field supervisor. All studies would be conducted using captive animals housed in the Hoga Island Research Laboratory and proposed studies must be non-lethal. Students must also check with their university advisor regarding their universities policies and procedures for working with cephalopod animals. Students are strongly encouraged to contact their project field supervisor early in the proposal development process.

Extended Project Summary


IN126 Are mutualistic relationships the norm?

(start dates 20 June, 27 June or 04 July; need to have completed reef survey techniques course and be dive trained if incorporating a diving element into the research))

This project has a waiting list

An evolutionary strategy for many species existing within mega biodiversity hotspots such as those of the coral triangle is to form mutualistic relationships with other species. Mutualistic relationships appear common and many examples have been well defined. Perhaps the clearest example of these are those that exists between anemones and their inhabiting anemonefish species and also the relationship between many species of fish and their cleaners such as the bluestreaked cleaner fish common to the Indo-Pacific. However, many other examples exist but have yet to be fully explored. Tight associations between species appear common place and inter-dependency between species is one of the main reasons relatively small areas can harbour such high levels of species richness. This research will explore the relationships between previously underexplored species by describing the interactions between different fish species inhabiting set areas of reef. For example several species of wrasse can be found to be associated with species of goatfish that feed within sandy sediments and the trumpetfish, especially at the juvenile stage, is often seen associated with other elongated fish where they seek refuge. This research is designed to highlight the commonality of mutualistic relationships and fish species interactions on reefs of different biological complexity. Research could also consider the implications of certain species loss and the interaction such loss has on ecological function.

Extended Project Summary


MA137 Regional biogeography, ecology and behaviour of nocturnal lemurs in the dry deciduous forest of northwestern Madagascar
 

(18 Jun – 28 July)

This project has a waiting list

Lemurs are 100% endemic to Madagascar and are confined to the remaining forest habitats of the island. They are a highly diverse taxonomic group (>100 species) and at the same time the most threatened group of mammals with about 94% of all assessed species being categorized as either vulnerable, endangered, or critically endangered (IUCN, July 2012). In this situation it is of utmost importance to understand their local and regional distribution as well as the behavioural constraints, ecological plasticity and ecological requirements of each lemur species in order to determine their vulnerability towards becoming extinct in the near future. Among the nine lemur species that have been reported from the Mariarano area, six are nocturnal (Microcebus murinus, M. ravelobensis, Cheirogaleus medius, Phaner pallescens, Lepilemur edwardsi, Avahi occidentalis). Nocturnal lemurs are generally much less studied than their diurnal cousins but face the same anthropogenic threats. They are therefore chosen as models for this project. The aim of this research is to study the abundance, spatial distribution, ecology, and behaviour of three different nocturnal lemur genera (Microcebus spp., Lepilemur edwardsi, Avahi occidentalis) in various forest fragments in the Mahamavo region, northwestern Madagascar.

Extended Project Summary


ME144 Spider monkey grouping patterns, habitat use and behaviour

(Start dates 12 June or 26 June; need to have completed ME001)

Spider monkeys are frugivorous primates that live in complex societies characterised by high degree fission-fusion dynamics whereby members of the same community are rarely all together and spend their time in fluid subgroups that constantly change in size and composition. Subgroup size is adjusted to food patch size and when fruit is abundant the spider monkeys can be found in large groups. Group size and composition can have a notable effect on activity budgets, ranging and social interactions, particularly as there are notable sex-differences in the quality of social relationships and the type of social interactions exchanged by males and female. A large community of spider monkeys in the Calakmul Biosphere Reserve has been studied each summer since 2013. The summer months are associated with the onset of rainy season and high fruit production resulting in large subgroups of spider monkeys. However in 2014 the reserve suffered a severe drought and during this time virtually no fruit was available. Using the long-term data set students can investigate changes to ranging patterns, subgroup composition and the associated effect on rates of social interactions in relation to rainfall patterns and food availability. Another project could focus on spider monkey activity and habitat use. Spider monkeys can have large home ranges that encompass different forest types, but it is not clear if they use all forest types for food and shelter. An investigation of how spider monkeys use the different forest types will determine whether spider monkey populations could survive in disturbed areas with limited availability of high forest. Activity budget data will be recorded using instantaneous scan sampling, noting the behaviour of each individual in view, the GPS location and forest type. Subgroup composition will be recorded in real time throughout the day and all occurrences of social interactions will be recorded noting the individuals involved, behaviour and context.

Extended Project Summary

 

ME146 Sea turtle nest site preferences and hatchling sex ratios

(Start dates 12 June or 26 June)

This project has a waiting list

There are seven species of sea turtle in the world, all of which are either threatened or endangered. The beaches of Akumal (meaning “home of the turtles”) are nesting ground for two of these species: the loggerhead turtle (Caretta caretta) and the green turtle (Chelonia mydas). One of the major aims of the ongoing turtle conservation project is to ensure that the turtles have access to suitable nesting sites on the beaches. In order to do so, it is necessary to understand the nesting site preferences of the green and loggerhead turtles and to ascertain the nest characteristics associated with successful incubation. Investigation of turtle nesting will record the number and location of green and loggerhead turtle nests, noting their distance from the shore, habitat characteristics, their depth, temperature inside the nest, number of eggs laid and number of successful hatchlings. As turtles are reptiles, the temperature inside the nest during the incubation period determines the sex ratio of hatchlings. Males are produced at lower temperatures than females and with beach temperatures on the rise due to climate change, there is major concern that sex ratios are highly female-skewed. It is not possible to determine the sex of hatchlings without dissection, but sex ratios can be inferred from mean nest temperature recorded on HOBO data loggers inserted into the nest during nesting. Variation in likely sex ratios can then be linked to nest site characteristics to determine areas of the beach that are able to produce males. In addition, the sheer number of turtles attempting to nest in the Akumal area results in turtles digging up existing nests on the beach due to a lack of space to make new nests. For this reason, it is necessary to relocate some of the nests into beach hatcheries and thus ensure careful management of the density of nests in the hatchery and the amount of shade they receive to maintain correct nest temperatures to produce balanced sex ratios of hatchlings.

Extended Project Summary


ME147 Effect of tourism on immature green turtle behaviour in Akumal Bay

(Start dates 12 June or 26 June)

This project has a waiting list

Year-round you can find immature green turtles (Chelonia mydas) feeding on the seagrasses in Akumal Bay. These turtles have become a popular tourist attraction and there is concern that both the number of tourists and the behaviour of tourists is affecting the behaviour and welfare of the turtles. Multiple studies of “swim with wild dolphin” based tourism has indicated that when the number of tourists gets too high, or the tourists attempt to touch them, the dolphins issue evasive responses to attempt to escape from the tourist and, if the tourism continues to maintain high numbers, the dolphins simply move their home range to areas inaccessible by tour boats. As the availability of healthy seagrasses in the Mexican Caribbean coastline is limited, the turtles in Akumal Bay may not have the option of leaving the area to avoid large numbers of tourists so the snorkel with turtle tours need to be strictly regulated. As Akumal Bay has just been declared a protected area, data is urgently required to determine the carrying capacity of snorkel based tourism. Research into green turtle behaviour will involve snorkelling with the turtles throughout the day to record their activity budgets and rates of evasive responses to tourists using focal animal sampling with continuous recording. Each turtle can be recognized individually and at the start of each focal sample the turtle will be photographed from various angles for subsequent identification from the turtle photo ID database. The number of tourists within a 5m radius of each turtle and the behaviour of these tourists (whether they abide by the rules and maintain a safe distance from the turtles or attempt to interact with them) will be recorded throughout each focal sample to determine the effect of tourism on turtle behaviour.

Extended Project Summary


ME148 Immature green turtle foraging behaviour and seagrass abundance in Akumal Bay

(Start dates 12 June or 26 June)

This project has a waiting list

There are three species of seagrass present in Akumal Bay: Thallassia testudinum, Siryngodium filiforme and Halodule wrightii. Ongoing monitoring of the foraging behaviour of the turtles has indicated a clear feeding preference for T. testudinum and unsurprisingly, ongoing monitoring of the seagrasses has indicated a decline in the abundance of T. testudinum. Immature green turtles naturally form large foraging groups and once a food patch has been depleted they move to a new area. However, limited availability of seagrasses in the Akumal area means that this may not be possible for the turtles in Akumal Bay and thus steps must be taken to sustainably manage the seagrasses. S. filiforme and H. wrightii seagrass remain abundant in Akumal Bay, but as turtle foraging on these grasses has been limited, the grasses lack digestible young shoots. Investigation into the state of the seagrasses and feeding behaviour of the turtles is therefore necessary to determine whether active management of the seagrasses (e.g. trimming the S. filiforme and H. wrightii to encourage new shoots to grow) is required to maintain a viable food supply for the turtles. Moreover, existing data shows that snorkel based tourism influences the movement patterns and foraging behaviour of the turtles resulting in heavy grazing of tourist-free areas and avoidance of seagrasses in areas where snorkel tours are prevalent. As Akumal Bay is now a protected area there is the option of re-zoning the bay to ensure that snorkel tours do not prevent turtles from accessing important areas of seagrasses, but data relating to seagrass coverage and turtle foraging behaviour is required to determine the specific location of tourist-free areas. Research into green turtle behaviour will involve snorkelling with the turtles throughout the day to record their foraging patterns. Seagrass quadrats surveys will be used to determine the availability of the various species of seagrasses, which can then be compared to turtle feeding preferences obtained from behavioural observations.

Extended Project Summary


PE158 Population monitoring and habitat preferences of primates in the Pacaya-Samiria Reserve

(Start dates 11 June or 25 June)

This project has a waiting list

As a result of seasonal variation in rainfall in the Andean headwaters, the rivers of the Amazon basin are subject to large fluctuations in water levels throughout the year that flood the surrounding forest. The Pacaya Samiria National Reserve is no exception, with as little as 2% of land in the reserve above water at the height of the flooded season. The forests of the National Reserve flood as the waters rise between December and June, and the onset of rainfall coincides with high fruit production that is the primary dietary component of a wide number of primate species. In recent years these normal seasonal changes in rainfall patterns have become more intense, which has been tentatively attributed to climate change. Consequently, dry and rainy seasons are more pronounced resulting in unpredictable food supply and the extent to which primate populations can adapt to these changes is not yet known. Investigation of the impact of changing rainfall patterns on the abundance, diversity and distribution of primates in the Pacaya Samiria Reserve will involve line transect surveys across forest types that flood to varying degrees with distance sampling to calculate density of primate species. These data may be added to the long term data set to investigate changes to primate abundance over time in relation to water levels. Forest structure and fruit availability data may be collected from a series of habitat plots spaced equidistantly along each transect. Each primate encounter can then be linked to the nearest habitat plot along the transect providing a corresponding set of habitat variables for primate record. From this, habitat preferences of each species may be calculated and the habitat variables affecting primate abundance and diversity at each plot can also be investigated.

Extended Project Summary

 

PE159 Niche separation in tamarins, howler monkeys, squirrel monkeys, and other primates in the Peruvian Amazon

(Start dates 11 June or 25 June)

This project has a waiting list

Multiple primate species can be found in rainforest habitats such as the Peruvian Amazon. In order to combat competition associated with several similar species living in close proximity, each species has evolved to occupy a specific niche within the habitat. These adaptations include differences in dietary requirements (frugivorous, folivorous and insectivorous primates), preference for different habitat types within the forest (e.g. seasonally flooded forest, upland forest and palm swamps) and variation in habitat use within the same forest type (e.g. occupying different heights within the forest canopy or variation in activity budgets). Twelve species of primates have been recorded in the Pacaya-Samiria National Reserve, but four species (brown capuchins, red howler monkeys, saddleback tamarins and common squirrel monkeys) are frequently encountered along the survey transects and are therefore best suited for dissertation projects. Upon locating a troop of one of these target species, the monkeys will be followed for as long as possible, behavioural data can be collected using instantaneous scan sampling and recording troop size, position in the canopy and food preferences. Fruit samples may also be collected to investigate species preference for colour and hardness.

Extended Project Summary

 

PE160 Behavioural changes during interspecific associations of primate groups in the Peruvian Amazon

(Start dates 11 June or 25 June)

This project has a waiting list

Interspecific associations are frequently observed between the various primate species found in Pacaya-Samaria Reserve, and the most frequent of these associations is between capuchin and squirrel monkeys. Living in groups has numerous benefits for individuals, including protection from predation and access to potential mates, but also has costs such as increased competition for food resources. In species which live in groups, such as primates in the Peruvian Amazon, the benefits of group living is assumed to outweigh the costs. Whether and how these costs and benefits change when a group of primates associate with another group of primates of a different species is not well understood. This project looks at how the behaviour of capuchin and/or squirrel monkeys changes, depending on the degree of association with individuals of the other species. Various aspects of monkey behaviour can be investigated, for example, looking at whether time spent being vigilant or feeding, or the type of food consumed changes with distance from individuals of other species. Upon locating a group of either capuchin or squirrel monkeys, the monkeys will be followed for as long as possible, and behavioural data will be collected using focal samples. Additional information, such as distance to the closest individual of another species, and the direction of movement of the whole group will be recorded.

Extended Project Summary


SW161 Assessing the behavioural effects of independent translocation of African Elephant

(Start date 24 June)

This project has a waiting list

Elephant populations in South Africa are among the healthiest in the world. Many small, private game reserves promote high elephant densities as they are a huge draw for tourists. However, the reserves are almost always fenced, meaning the natural long migrations of elephants cannot occur. Large elephant populations in restricted areas are leading to high levels of vegetation damage in some reserves. This problem was particularly significant in Pongola Game Reserve, where the calculated carrying capacity of 37 elephants had more than doubled to over 80 elephants. Opwall and its partners have been monitoring the Pongola elephants for over seven years in order to assess the behavioural impacts of bull vasectomies, which were performed in an attempt to halt population growth. While Pongola Game Reserve was fenced, one border of the reserve was demarcated by a lake. The drought experienced by southern Africa in the summer of 2015/16 reduced the level of the lake so much that around 50 elephants were able to simply walk around the fence into the adjacent Royal Jozini Big 6 Reserve* in Swaziland. RJB6 had no elephants prior to this, and luckily welcomed the new additions to their reserve. This successful, independent translocation of elephants is incredibly rare, and gives us a unique opportunity to compare pre- and post-translocation behaviour. Our main focus will be to study the ranging patterns and dominance behaviours of the translocated elephants to investigate how this move has affected the herd. Habitat assessment data will also be collected to determine if the impact the herd are having on the new reserve is sustainable.

Extended Project Summary