Mammal topics

HO109 Variation in cloud forest small mammal populations and their microhabitats, Honduras

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

A total of 19 small mammal species have been recorded in Cusuco National Park comprising a complex community. However, three focal species are of interest and dominate the community: 1) Desmarest’s spiny pocket mouse (Heteromys desmarestianus) which occurs on the forest floor >150m from the nearest river (terrestrial environment), 2) the Mexican deer mouse (Peromyscus mexicanus) which occurs along river corridors <3m from the water’s edge (riparian environment), and 3) a currently unidentified Rheomys spp. watermouse which is entirely aquatic and forages by diving within upland rocky streams (riverine environment). Therefore, three traplines are set at each of seven camps throughout the park, each consisting of 12 traps placed approx. 10m apart. These traplines are set up in each microhabitat targeting each of the three small mammal species for comparative and individual study. How these species share the forest and the individual specialism of each species remains largely unknown. Small mammal abundance and species composition can be related to habitat data collected from permanent plots along the transect network (for example forest structure, tree density, % fruiting, leaf litter depth etc.). Additionally, abundance and special distribution patterns may be related to predator abundance and distribution (mainly large snake species including Wilson’s pit viper, Cerrophidion wilsoni), building up a picture of the trophic relationships in the region.

Extended Project Summary


HO110 Using camera traps to quantify human disturbance of large mammal species, Honduras

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

Large mammals, despite their size, are rarely observed in forest habitats and are often under-represented in biodiversity studies. By using indirect survey techniques to increase detectability, a total of 23 large mammal species have been recorded in Cusuco National Park using field signs such as footprints or droppings. These include the endangered Baird’s tapir and species which are commonly hunted for bushmeat such as red brocket deer and white collared peccaries. Camera traps are deployed throughout Cusuco National Park, placed either within 20m of the sample route network or up to 300m away from the sample routes. This enables us to examine the distribution of large mammals throughout the park with respect to distance from the park boundary, human habitation and nearby deforested patches and also distance from our transect network, focusing on the effect of human disturbance. For key target species for which there are >10 detections throughout the season, the Random Encounter Model (REM) may be employed to estimate probable abundance. Data from previous years will be available for comparison enabling temporal trends in detections to be assessed. NOTE: this project involves hiking the entire transect network and also considerable distances off transect. The park has an average slope of 30°. Thus, moderate to high levels of physical fitness are essential for students undertaking this project.

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


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

This project has a waiting list

(18 June – 28 July)

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


ME143 Large mammal abundance and distribution patterns in relation to habitat characteristics and hunting in the Mayan forest

Large mammal density at Calakmul Biosphere Reserve is very high and the forest is one of the last remaining strongholds of endangered mammals such as spider monkeys, jaguar and tapir. Although these species are not hunted, indigenous people are allowed to hunt other large mammals such as peccary and deer (which are the preferred prey of jaguar and puma). The tropical semi-deciduous forest in the Calakmul Biosphere Reserve is unusual in that areas close to the Mayan Ruins contain unusually high densities of large fruiting trees (the result of Ancient Mayan agro-forestry) in comparison to other areas. As there are no rivers or streams in the reserve,
forest structure is also heavily affected by distance from the few permanent water sources in the reserve known as aguadas. The aim of the large mammal research project is to investigate the relationship between habitat characteristics and large mammal abundance and ranging, and to investigate the impact of hunting of preferred prey species on the abundance and distribution of felids. Mammal abundance data will be collected along a series of forest transects using distance sampling (based on visual sightings of more commonly encountered species such as primates) and patch occupancy sampling (based on tracks and signs of more elusive species such as tapir and jaguar). Additional data will be collected using camera traps enabling comparison of density estimates produced by the different types of surveys. The survey transects are distributed across a wide range of forest habitat types and each transect contains a number of 20m x 20m habitat survey plots. In each of these plots, tree species will be identified, and DBH and tree height will be measured. Large mammal data from each transect can then be related to mean habitat characteristics for the transect and comparisons between mammal abundance and habitat variables may be investigated.

Extended Project Summary


ME145 Bat abundance, diversity and distribution patterns in relation to habitat characteristics of the Mayan forest

(start dates 12 June or 26 June; need to complete ME001)

Bat abundance in the Calakmul Biosphere Reserve is very high due to the presence of multiple caves that act as roost sites. There are over 90 bat species that occur in tropical Mexico, but the presence of the majority of these species in Calakmul remains unclear due to lack of standardized studies. Moreover, bat diversity is unlikely to be uniform throughout the reserve due to changes in the habitat resulting from vicinity to ruins sites (Mayan ruins contain unusually high densities of large fruiting trees as a result of Ancient Mayan agro-forestry) and the limited water supply in the reserve. Students will investigate bat abundance and diversity using mist net surveys in conjunction with bat detectors that record bat vocalizations. These combined methods will provide data on the carnivorous, frugivorous and nectivorous bats that are frequently caught in the nets and the insectivorous bats that have such fine-tuned echolocation that they can detect mist nets and are therefore virtually impossible to capture. These data will be collected across a range of transects in the reserve that encompass different habitat characteristics. Each transect contains a number of 20m x 20m habitat survey plots that provide detailed information of the forest characteristics in the area. In each of these plots, tree species will be identified, tree DBH, understorey vegetation, canopy openness, and the number of saplings will be measured. Bat data from each transect can then be related to mean habitat characteristics for the transect and comparisons between bat diversity and habitat variables may be investigated.

Extended Project Summary


PE157 Population trends and habitat preferences of pink and grey river dolphins in the Peruvian Amazin

(start dates 11 June or 25 June)

The pink dolphin Inia geoffrensis and grey dolphin Sotalia fluviatilis are endemic to the Amazon rivers and function as indicator species for the general health of aquatic habitats. Dolphins make an excellent indicator species because they rapidly move out of polluted or degraded habitats and in turn quickly indicate changes in the condition of aquatic systems. Moreover, dolphin abundance directly relates to food supply and thus dolphins can be used to monitor the sustainability of fishing by local communities. The dolphins are also easy to count and observe since they frequently surface, are large-bodied and very distinctive. The river dolphin population in the Pacaya-Samiria has been monitored for several years using fixed-width transects along rivers, lakes and channels via small boats. During these surveys, all dolphin encounters are recorded noting the species, number of individuals, habitat in which the dolphins were seen and the dolphin behaviour. Dissertation topics could examine the health of the aquatic systems in the Peruvian Amazon by evaluating population trends of the two species of river dolphin over time, or could focus on habitat, behaviour and group size differences between the two species. Dissertations could also incorporate the long-term fish monitoring dataset to investigate changes to dolphin abundance over time in relation to changing fish stocks.

Extended Project Summary


SW161 Assessing the behavioural effects of independent translocation of African Elephants

(start date 24 June)

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


SW162 Calculating the carrying capacity of the Royal Jozini Big 6 Reserve for elephant populations

(start date 24 June)

In 2016, around 80 elephants broke free of their home and moved to the greener pastures of Royal Jozini Big 6 Reserve in Swaziland. The reserve management were happy to receive the elephants, but due to the unplanned nature of this translocation were unable to properly assess the elephant carrying capacity of the reserve prior to their arrival. Determining elephant carrying capacities for small fenced reserves is difficult, and many different densities have been put forward as reasonable estimates for the number of elephants any given area of land can sustain. However, these estimates are unlikely to be transferable from one reserve to another due to differences in rainfall, water availability, vegetation etc. The nearby Pongola Game Reserve has been estimated to be capable of sustaining 0.38 elephants per square kilometre. However, research has shown that other reserves, such as Kruger National Park, should be able to sustain densities of up to 1.5 elephants / km2. The reserve management therefore needs a carrying capacity estimate based on the actual composition of the RJB6 reserve. Vegetation assessments will be conducted in order to quantify the amount of damage being caused by the elephants and accurately assess the available browse across the reserve. These data could then be used to help set elephant carrying capacity levels in terms of how many would be sustainable to keep levels of habitat damage below pre-determined levels (e.g. less than 20% of the area must have 40% or more trees and shrubs in the top 3 categories of the Walker damage scale). The position of the elephant herds has been noted virtually daily since 2008 in both Pongola and RJB6, allowing an accurate assessment of ranging patterns and habitat preferences. This positional data could be plotted on GIS programs to calculate areas of differential elephant usage and compared between the two reserves.

Extended Project Summary


SO163 Factors affecting the population size and distribution of large mammals in Kwa-Zulu Natal

(start date 24 June)

Until recently, Pongola Game Reserve was home to a very high density of elephants. These elephants caused a great deal of damage to the vegetation and dominated much of the landscape within this small fenced reserve. In early 2016, the elephant population dropped dramatically and suddenly when most of the herds broke free and moved into a nearby reserve. The Pongola elephants had a detrimental effect on the vegetation in the reserve, but the follow-on effects on other large mammals have not been studied. Since the elephants have translocated, the other herbivores in the reserve now have access to browse and graze that was previously dominated by the elephants. Populations of other herbivores should flourish with the reduced elephant numbers, but the damage to the vegetation they caused may have long-term effects. By assessing the populations and habitat preferences of species such as zebra, wildebeest, kudu and impala, students will be able to quantify how a reserve can recover from such massive amounts of damage. During the regular large mammal surveys, all visual encounters with the herbivores are recorded, noting the GPS location of the animal, the species, condition score, number of individuals, age-sex class of each individual and habitat type. GIS maps showing the distribution of vegetation types, habitats, water courses and man-made structures in the reserve can be produced, allowing comparison with the herbivore distribution data.

Extended Project Summary


SO164 Monitoring the populations and ranging patterns of the critically endangered black rhino

(start date 24 June)

The critically endangered black rhino once ranged throughout southern Africa, but a devastating poaching wave in the early 1990s reduced their numbers to just 2000. Now, many initiatives are working towards protecting land containing good black rhino habitat, in order to increase the numbers of growth rate of this endangered species. The Black Rhino Range Expansion project, a collaboration between WWF and Ezemvelo KZN Wildlife, has helped create 10 new black rhino populations in South Africa. Thanks to initiatives like this, the overall population of black rhino is increasing throughout Africa. But ensuring the long-term success of this initiative requires constant monitoring and further gathering of knowledge regarding the new rhino populations. Opwall students have the rare opportunity to assist this project by collecting behavioural and ranging data on a small population of black rhinos in the Kwa-Zulu Natal region within the Pongola reserve. These rhinos were introduced into the reserve in 2006, and have been closely monitored by the onsite researcher for the majority of that time. Data collected in 2017 will be added to long term data sets to provide further information regarding the ranging patterns and interactions of an established population of this enigmatic species.

Extended Project Summary


TR168 Bat species distribution and abundance in relation to land composition within the Tarnava Mare

(start date 28 June)

Since 2014 the species of bat present in 8 villages across the Tarnava Mare region have been assessed. A combination of static recorders and hand held detectors have been used along two transects in each village, allowing a good picture of bat species presence to be gained. A number of possible influencing factors such as light sources, roost availability and landscape composition could also be explored. This project will involve repeating the bat surveys and then analysing the data in conjunction with GIS-based land cover maps that are being updated each year. This could reveal whether there are particular land cover combinations which support the greatest abundance and diversity of bats. Similarly, this technique could be used in combination with other influencing factors.

Extended Project Summary


TR171 Mammal abundance and landscape composition

(start date 28 June)

In 2016 the relative abundances of larger mammals, including bear, roe deer, wild boar, fox and marten, were assessed by recording signs of presence (scat and tracks) along survey routes at each of 7 villages across the Tarnava Mare region. The data suggest that the broad scale landscape composition – the mosaic of different land cover types – may influence population densities and hence the frequency with which these larger mammal signs are encountered. This project would involve repeating the larger mammal surveys and then analysing the data in conjunction with GI