Readings Flashcards
Outline Valin et al. 2005
Proximate question
Method: on Peacock butterflies predated by Bluetits
- Eyespots + sound, eyespots - sound, - spots - sound
- Used black marker to cover eyespots
- Also had controls with marker on other bits of the wing
Results:
- Eyespots significantly reduced predation
- Hissing did not
- Combined = no additional effect
- Hissing may be useful against other predators
Outline the aims and methods of Bell et al. 2014
- Subordinate females help dominant females by raising their pups
- Dom female meerkats supress subs from reproducing using agression, eviction or infantcide
- Infanticide adaptive = nestmates litters killed so own offspring doesn’t have to compete
- Ultimate
Methods:
- 12 groups of wild meerkats in SA
- Sub females injected with contraceptive
- Measured: Agression levels, eviction rate, helper-pup ratio, repro success of doms
Outline the results and concs of Bell et al. 2014
Results and concs
Results:
- Dom females showed less aggression and evicted fewer subs
- Higher ratio of helpers to pups
- Dom females improved foaging efficacy
- Pups were heavier when born and grew at a faster rate
Concs:
- Confirm hypothesis that dominant females suppress subordinate breeding because it reduces their offsprings fitness
Outline the aims and methods of Deal et al. 2017
- Proximate
- Examines how predation risk from perch affects male sand gobies’ filial cannibalism and nest construction behaviours
- Trade off between investment in current and future offspring when under predation
Method:
- Sand Gobies placed in experimental environs with / without predator (Perch)
Outline the results and concs from Deal et al. 2017
Results:
- Total filial cannibalism was less common when predators present ( nonsignificant)
- No significant results for partial filial cannibalism
- When predator present, total cannibals created taller and wider nest entrances
Concs:
- Total fililal cannibalism influenced by predation risk, males avoided complete brood consumption in the presence of predators
- Changes to nest architecture = complex trade offs
Outline the aims and methods of Lenz et al. 2018
- Proximate study into cryptic female post-copulatory choice in Sticklebacks
- Eggs may favour sperm with preferred level of Major histocompatibility complex (MHC) similarity
- As random fertilisation can = nonoptimal haplotype combos
Method:
- Eggs exposed to sperm from 2 males in vitro (= 4 potential haplotypes)
- Measured av sequence divergence between parental MHC alleles
Outline the results and concs of Lenz et al. 2019
Results:
- Non-random fertlisation: favours intermediate MHC divergence
- Suggests eggs select sperm with optimal MHC = enhancing immune gene diversity
- Replication confirms findings
- Additional analysis also showed a pref for more similar MHC haplotypes
Concs:
This sophisticated mechanism counteracts the randomness of the Mendelian segregation, optimising offspring imunnocompetence + high genetic diversity
Outline the aims and methods of Albo et al. 2013
- Ultimate study into post copulatory cryptic female choice in polyandrous system with nuptial gifts as a honest signal (Pisaura mirabilis spiders)
- Do females store sperm from males that give higher-quality gifts
Methods:
- NG (No Gift): Males without a gift.
- GT (Gift-Terminated): Males with a gift but copulation was terminated early.
- G (Gift): Males with a gift allowed to copulate uninterrupted.
- Mating behaviour, copulation duration, and number of pedipalp insertions were observed
- Sperm count measured
- Hatching success measured
Outline the results and concs of Albo et al. 2013
Results:
- Females in NG group stored fewer sperm than GT group, G had the highest sperm storage
- +ive relationship between copulation and no. sperm stored in G group
Concs:
- Supports that female P. mirabilis exercise cryptic sperm choice
- Implies male condition and gift quality are interconnected traits selected for by females = selection pressure on gifts
- Female indirect benefits: attractive offspring with increased fitness
- Nuptial gifts extend copulation, enhance sperm transfer = improving male repro success
Outline the aims and methods of Baird et al. 2021
- Proximate study into how wind affects flight control in honeybees
- Focusing on how bees adjust their ground height to maintain constant visual info (optic flow)
Method:
- Bees trained to fly along a wind tunnel to a sugar feeder
- Various wind speeds and textures tested
- Ground speed and height calculated
Outline the results and concs. of Baird et al. 2021
- Bees maintain constant ground speed in head/tail winds by relying on strong optic flow cues
- Bees adjust altitude to maintain a steady rate of longitudinal optic flow
- When optic flow cues reduced they increase ground speed
- They use transverse optic flow to regulate flight altitude
- Suggests they perform transverse oscillations (side-to-side movements) to measure and control altitiude
Outline the aims and methods of Shackleton et al. 2016
- Investigates the trade-offs in honeybee foraging on high quality (nectar) vs high quantity (fruit juice) resources
Methods:
- Observed worker bees foraging on 2 wildflower species and on fallen guava fruit
- Measured: Rate of weight gain, sugar conc. in crops, no. of visits and time spent harvesting vs travelling, temp
Outline the results and concs of Shackleton et al. 2016
Results:
- Bees eating fruit gained weight faster
- Sugar conc. lower in fruit juice
- Fruit foragers visited fewer fruits per min, but more time on fruit. Flower foragers visited more flowers per min but less handling time
- Flower foraging ceased in afternoon, fruit continued until sunset
Concs:
- Bees have flexible forganing strategies, and use resources based on current needs and availability
- Crucial to maintain colony health
- Overall, bees gathered fruit faster than nectar due to larger vol. available and lower viscosity = aligns with the quality-quantitiy continuum prediction
Outline the aims and methods of Flower et al. 2014
- Investigates deceptive tactics of the fork-tailed drongo bird, uses false alarm calls (their own and mimicked) to scare other species and steal their food)
- Study tests whether drongos flexibily vary false calls to maintain deception and evade habituation by targets
Methods:
- Tests whether target species are more deceived by mimicked alarms compared to drongo-specific alarms (measured response times)
- Tests whether varying calls during repeated food-thefts keeps scaring the targets (measured duration of target reactions)
Outline the results and methods of Flower et al. 2014
Results:
- Drongos that mimicked alarm calls of target species were more successful in decieving them (compared to drongo-specific calls)
- Repeated use of alarm call type decreased target response, but varying type maintained response intensity and prevented habituation
- Drongos more likley to vary alarm type after a failed theft attempt
Concs:
- Ability to change signals based on feedback suggests cognitive complexity
