Here we provide a list of research projects that would help us to understand the socio-ecology of bush Karoo rats.
Projects are designed they work for master theses in South Africa: 1 year preparation with proposal writing and learning field techniques followed by one year of data collection, analysis and writing up.
Some projects need less field work and might be suitable for students from overseas like Europe.
Some of these topics could be combined to a PhD or postdoc projects.
For most projects listed here, the basic research equipment is available at SKRS, but not the funding.
Thus, funding for travel, accommodation at SKRS, research fee (negotiable) and student stipend must be organized by the student and her supervisor. CLICK HERE FOR INFO.
If you are interested in any of these projects, write to [email protected] and add your CV and motivation letter (which should also indicate the period you could come to SKRS, funding).
Projects are designed they work for master theses in South Africa: 1 year preparation with proposal writing and learning field techniques followed by one year of data collection, analysis and writing up.
Some projects need less field work and might be suitable for students from overseas like Europe.
Some of these topics could be combined to a PhD or postdoc projects.
For most projects listed here, the basic research equipment is available at SKRS, but not the funding.
Thus, funding for travel, accommodation at SKRS, research fee (negotiable) and student stipend must be organized by the student and her supervisor. CLICK HERE FOR INFO.
If you are interested in any of these projects, write to [email protected] and add your CV and motivation letter (which should also indicate the period you could come to SKRS, funding).
Title: Parasite load
Question: Is solitary living a goo strategy to decrease parasite load?
Hypotheses: 1. BKRs living in small groups have more parasites than solitary BKRs. 2. Striped mice have more parasites than BKRs.
Methods: Measure ecto-parasites (combing). Measure endo-parasite from faeces.
Field stay (season and duration): Minimum of 6 months.
Limits: Needs good protocol. We have no experience with measuring endo-parasites. Problem to get research permits for parasites in South Africa.
Additional info: Would be great to measure viruses and bacteria.
Title: Post-partum estrus: How common?
Question: How often do wild living rodents really have a successful post-partum estrus? Which factors influence whether females are successful in this or not?
Hypotheses: Predictors of inter-birth intervals include age, body mass, food availability, social situation, population density.
Methods: Determine for female striped mice and female bush Karoo rats for multiple year the inter-birth interval to determine whether they do use post-partum estrus.
Field stay (season and duration): Minimum of 3 months to learn about the project and database. Data analysis can be done in Goegap or at home university.
Limits: Student needs to develop good statistical skills, especially GLMM.
Additional info: Female rodents have post-partum estrus, thus they become fertile soon after giving birth. Under ideal conditions in captivity, they then become immediately pregnant again. This explains their high reproductive rate. However, little is known about wild living rodents and our experience shows that females often do not have post partum estrus, but instead become pregnant when their current litter is weaned, just like primates.
Title: Anogenital distance, personality and intra-uterine situation
Question: The anogenital distance is an indicator of exposure to androgens in utero. Are females with a larger distance more aggressive? Do we find indication that the anogenital distance is related to sibling sex?
Hypotheses: 1. Positive correlation between anogenital distance and personality. 2. Sibling sex influences anogenital distance, especially females from twin litters that had a brother have a larger distance than females that had a sister.
Maternal effects: If being next to a brother in utero leads to masculinisation and increased basal testosterone levels, then a masculinized female might produce hypermasculinized daughters in male-female twins!
Methods: Personality testing during a minimum for 1 season for hypothesis 1. For hypothesis 2, long-term data are available.
Field stay (season and duration): Minimum of 1 year.
Limits:
Additional info: Ethical permit needed for personality.
Also consider other personality traits. Note: Litters of only two offspring are common, making it a good study system! (Correa, Frugone & Soto-Gamboa 2013; Fouqueray et al. 2014).
Title: Individual and kin recognition
Question: BKRs differentiate between kin and non-kin neighbours. How do they recognise kin?
Hypotheses: 1. Olfactory recognition. 2. Recognition by familiarity.
Methods: Tests with olfactory cues. More to be developed
Field stay (season and duration): Minimum of .1 year.
Limits: Some tests would be best done in captivity (cross-fostering), but currently we do not have a captive colony
Additional info: Ethical permits needed).
Title: Runways, mental maps and “bekannter Weg“
Question: What do BKRs actually use their runways for? Do the runways constrain them, or help them to escape faster?
Hypotheses: To be developed. What surprised us in 2023 was that on camera trap put at runways we rarely saw BKRs (>1 per day), when we expected that they use them all day long for foraging. So what do they really use them for?
Uexküll and Kiszat (1934) describes how animals use for orientation the way the know, even if its longer. He mentions that rats will still use for a long time their known way even when a shorter direct way is available.
Methods: Observations, camera traps, experiments (1. trap BKRs, release them at a place where an unknown shelter is closer than a known one; 2. trap BKRs, release them at a place where an shelter connected to by runway is further away another alternative one), to be developed by student.
Field stay (season and duration): Minimum of 1 year.
Limits:
Additional info: Ethical permits.
Title: Synchronisation of births (can be combined with male tactics and socio-genetics to a PhD project)?
Question: How is it possible that even though we trap hardly any adult breeding male during the breeding season, females are always pregnant? Are all females fertilised the same days? Are births synchronised in the solitary population?
Hypotheses: To be developed by student.
Methods: Trapping and existing long-term data.
Field stay (season and duration): Minimum 6 months
Limits:
Additional info: We have all needed permits.
Title: Lodge structure
Question: What parts do BKR lodges consist of? Are there really platforms, different levels? Whatdoes the sleeping chamber look like, it it above or below ground, how is it reached, how many BKRs fit in here?
Hypotheses: It’s a descriptive study but one that needs to become accurate. Several old studies describe lodge structure in an anecdotal way, but not in a organised way.
Hypotheses can be developed, for example regarding size and age of lodges and complexity of structure.
Methods: Describe in detail structure of 80-160 lodges at the field site. Lodges vary in age and size. For this, a proper protocol needs to be established.
At another site, deconstruct 12 lodges. Include estimate of mass of branches used, different sizes of branches, number of branches, etc.
Field stay (season and duration): Minimum 1 year.
Limits: We will need to find a place where we are allowed to deconstruct 12 lodges.
Additional info: Check needed permits, Goegap ok. Possibility to include iButton data loggers to measure temperatures in lodges.
Title: Onset of Breeding
Question: When do BKRs start breeding, is this regulated by rain, food, temperature? When do young females start reproducing, differences between different birth cohorts, and is this related to survival to the next breeding season?
Hypotheses: To be developed by student
Methods: Long-term trapping data, plant survey data, and weather data.
Field stay (season and duration): Minimum 1 year.
Limits: Students must have good knowledge of R and be able to improve it.
Additional info:
Title: Fur Colour as Camouflage
Question: Is the fur colour of bush Karoo rats and of striped mice decreasing predation risk?
Hypotheses: 1. Mouse models with stripes receive less predation attacks than models without stripes. 2. Grey bush Karoo rat models received less predation attacks at lodges than models painted in striped mouse colors. 3. Away from lodges, grey bush Karoo rat models received more predation attacks than models painted in striped mouse colors
Methods: 3D printed models of mice and of bush Karoo rats. These will be painted with different colours.
Field stay (season and duration): Minimum of 6 months in the field. Any season, though dry season might be better.
Limits: Number of predators changes a lot from year to year.
Additional info: Check needed permits, Goegap ok, ethical permits (for raptors).
Title: Ultra-sound communication (PhD student; also possible for master student; even a master student from South Africa who could try to get a grant to go to France from Campus France. The course in St Etienne is only from September-December, data collection and writing can be done in South Africa.
Question: Is there ultra-sound communication between neighbours in this solitary living mammal?
Hypotheses:
a) I expect that ultrasound-communication differs between kin and non-kin neighbors.
b) I will test whether neighboring female kin use ultrasound communication as an alarm call to warn each other.
c) I predict that the ultrasonic vocalization plays an important role in courtship (attracting mates) and in territoriality (keeping competitors away from lodges).
Methods: Ultra-sound recorders from St Etienne and complex statistical analyses.
Field stay (season and duration): Minimum of two years: One to write proposal and apply for funding to go to France, then 4 months in France followed by a minimum of 6 months data collection in the field followed by analysis and writing up.
Limits: Student must be highly motivated to get a grant. Student must be able to learn complex statistical analysis. Student would need her own proper laptop.
Additional info: Check St. Etienne for collaboration.
Question: Is solitary living a goo strategy to decrease parasite load?
Hypotheses: 1. BKRs living in small groups have more parasites than solitary BKRs. 2. Striped mice have more parasites than BKRs.
Methods: Measure ecto-parasites (combing). Measure endo-parasite from faeces.
Field stay (season and duration): Minimum of 6 months.
Limits: Needs good protocol. We have no experience with measuring endo-parasites. Problem to get research permits for parasites in South Africa.
Additional info: Would be great to measure viruses and bacteria.
Title: Post-partum estrus: How common?
Question: How often do wild living rodents really have a successful post-partum estrus? Which factors influence whether females are successful in this or not?
Hypotheses: Predictors of inter-birth intervals include age, body mass, food availability, social situation, population density.
Methods: Determine for female striped mice and female bush Karoo rats for multiple year the inter-birth interval to determine whether they do use post-partum estrus.
Field stay (season and duration): Minimum of 3 months to learn about the project and database. Data analysis can be done in Goegap or at home university.
Limits: Student needs to develop good statistical skills, especially GLMM.
Additional info: Female rodents have post-partum estrus, thus they become fertile soon after giving birth. Under ideal conditions in captivity, they then become immediately pregnant again. This explains their high reproductive rate. However, little is known about wild living rodents and our experience shows that females often do not have post partum estrus, but instead become pregnant when their current litter is weaned, just like primates.
Title: Anogenital distance, personality and intra-uterine situation
Question: The anogenital distance is an indicator of exposure to androgens in utero. Are females with a larger distance more aggressive? Do we find indication that the anogenital distance is related to sibling sex?
Hypotheses: 1. Positive correlation between anogenital distance and personality. 2. Sibling sex influences anogenital distance, especially females from twin litters that had a brother have a larger distance than females that had a sister.
Maternal effects: If being next to a brother in utero leads to masculinisation and increased basal testosterone levels, then a masculinized female might produce hypermasculinized daughters in male-female twins!
Methods: Personality testing during a minimum for 1 season for hypothesis 1. For hypothesis 2, long-term data are available.
Field stay (season and duration): Minimum of 1 year.
Limits:
Additional info: Ethical permit needed for personality.
Also consider other personality traits. Note: Litters of only two offspring are common, making it a good study system! (Correa, Frugone & Soto-Gamboa 2013; Fouqueray et al. 2014).
Title: Individual and kin recognition
Question: BKRs differentiate between kin and non-kin neighbours. How do they recognise kin?
Hypotheses: 1. Olfactory recognition. 2. Recognition by familiarity.
Methods: Tests with olfactory cues. More to be developed
Field stay (season and duration): Minimum of .1 year.
Limits: Some tests would be best done in captivity (cross-fostering), but currently we do not have a captive colony
Additional info: Ethical permits needed).
Title: Runways, mental maps and “bekannter Weg“
Question: What do BKRs actually use their runways for? Do the runways constrain them, or help them to escape faster?
Hypotheses: To be developed. What surprised us in 2023 was that on camera trap put at runways we rarely saw BKRs (>1 per day), when we expected that they use them all day long for foraging. So what do they really use them for?
Uexküll and Kiszat (1934) describes how animals use for orientation the way the know, even if its longer. He mentions that rats will still use for a long time their known way even when a shorter direct way is available.
Methods: Observations, camera traps, experiments (1. trap BKRs, release them at a place where an unknown shelter is closer than a known one; 2. trap BKRs, release them at a place where an shelter connected to by runway is further away another alternative one), to be developed by student.
Field stay (season and duration): Minimum of 1 year.
Limits:
Additional info: Ethical permits.
Title: Synchronisation of births (can be combined with male tactics and socio-genetics to a PhD project)?
Question: How is it possible that even though we trap hardly any adult breeding male during the breeding season, females are always pregnant? Are all females fertilised the same days? Are births synchronised in the solitary population?
Hypotheses: To be developed by student.
Methods: Trapping and existing long-term data.
Field stay (season and duration): Minimum 6 months
Limits:
Additional info: We have all needed permits.
Title: Lodge structure
Question: What parts do BKR lodges consist of? Are there really platforms, different levels? Whatdoes the sleeping chamber look like, it it above or below ground, how is it reached, how many BKRs fit in here?
Hypotheses: It’s a descriptive study but one that needs to become accurate. Several old studies describe lodge structure in an anecdotal way, but not in a organised way.
Hypotheses can be developed, for example regarding size and age of lodges and complexity of structure.
Methods: Describe in detail structure of 80-160 lodges at the field site. Lodges vary in age and size. For this, a proper protocol needs to be established.
At another site, deconstruct 12 lodges. Include estimate of mass of branches used, different sizes of branches, number of branches, etc.
Field stay (season and duration): Minimum 1 year.
Limits: We will need to find a place where we are allowed to deconstruct 12 lodges.
Additional info: Check needed permits, Goegap ok. Possibility to include iButton data loggers to measure temperatures in lodges.
Title: Onset of Breeding
Question: When do BKRs start breeding, is this regulated by rain, food, temperature? When do young females start reproducing, differences between different birth cohorts, and is this related to survival to the next breeding season?
Hypotheses: To be developed by student
Methods: Long-term trapping data, plant survey data, and weather data.
Field stay (season and duration): Minimum 1 year.
Limits: Students must have good knowledge of R and be able to improve it.
Additional info:
Title: Fur Colour as Camouflage
Question: Is the fur colour of bush Karoo rats and of striped mice decreasing predation risk?
Hypotheses: 1. Mouse models with stripes receive less predation attacks than models without stripes. 2. Grey bush Karoo rat models received less predation attacks at lodges than models painted in striped mouse colors. 3. Away from lodges, grey bush Karoo rat models received more predation attacks than models painted in striped mouse colors
Methods: 3D printed models of mice and of bush Karoo rats. These will be painted with different colours.
Field stay (season and duration): Minimum of 6 months in the field. Any season, though dry season might be better.
Limits: Number of predators changes a lot from year to year.
Additional info: Check needed permits, Goegap ok, ethical permits (for raptors).
Title: Ultra-sound communication (PhD student; also possible for master student; even a master student from South Africa who could try to get a grant to go to France from Campus France. The course in St Etienne is only from September-December, data collection and writing can be done in South Africa.
Question: Is there ultra-sound communication between neighbours in this solitary living mammal?
Hypotheses:
a) I expect that ultrasound-communication differs between kin and non-kin neighbors.
b) I will test whether neighboring female kin use ultrasound communication as an alarm call to warn each other.
c) I predict that the ultrasonic vocalization plays an important role in courtship (attracting mates) and in territoriality (keeping competitors away from lodges).
Methods: Ultra-sound recorders from St Etienne and complex statistical analyses.
Field stay (season and duration): Minimum of two years: One to write proposal and apply for funding to go to France, then 4 months in France followed by a minimum of 6 months data collection in the field followed by analysis and writing up.
Limits: Student must be highly motivated to get a grant. Student must be able to learn complex statistical analysis. Student would need her own proper laptop.
Additional info: Check St. Etienne for collaboration.
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