Brilliant Bats and Co-evolution

Brilliant Bats and Co-evolution

• Brilliant bats are an example of co-evolution, where two species evolve in response to each other.
• This includes predator-prey relationships (bats hunting moths), and plant-pollinator relationships (bats pollinating flowers).

Bat Diet

• Bats eat a variety of foods, including arthropods, plants, and even vertebrates.
• Different bat families have different diets.
• Some bats eat insects, others fruits. Some bats are insectivores or frugivores.

Foraging Modes

• Some bats glean food, others eavesdrop or use echolocation.

Vision

• Some bats see in monochromatic, others dichromatic.

Predator Avoidance

• Bats use several methods of predator avoidance, such as escape, fooling the predator, disappearing, or annoying the predator.

Tympanate Moths

• Many moths have evolved hearing to avoid bats.
• Moths have ears to detect bat sonars.
• Moth ears have evolved 10-12 times.
• Moths vary their response methods based on hearing.

Being a Bat

• Bats emit short pulses, typically ranging in 25 kHz to 150 kHz, to echolocate prey.
• Bats' outer ears act like two receivers due to a specialized skin flap called the tragus (not present in all species).
• The tragus creates elevation-dependent spectral changes in echoes.

Echolocation Calls

• Echolocation calls vary in duration and frequency across different bat species.
• Most bat calls are one of two types: either frequency-modulated (FM) or constant frequency (CF).
• Different types of echolocation calls are used for different types of prey.

Being a Bat (continued)

• Bats use FM signals to locate prey.
• Bats use CF signals for hunting fluttering prey in dense vegetation.
• Bats employ acoustic strategies (calls, etc) in reverberant or cluttered environments to improve precision.
• Some bats can eavesdrop or "eavesdrop" on foraging areas.

Bat Defense Tactics

• Some insects (moths and other insects) have developed various escape tactics for dodging or disrupting bat echolocation.
• Some insects have developed behaviors like erratic flight trajectories, dropping to the ground or emitting ultrasonic clicks to confuse the bat's prey location.
• Moths have evolved ultrasound-detecting ears in order to evade bats efficiently.
• Moths mechanically tune their ears to higher frequencies used by hunting bats.

Escape Tactics

• Escape rule 1 involves maximizing radial acceleration.
• Escape rule 2 involves turning toward the threat.
• Escape rule 3 involves fleeing at an intermediate distance.

Mantis Defenses

• Selection favors mantis species that are active when bats are active, so they can hear higher frequencies.

Confuse!

• Some species use clicks to jam or confuse bats.
• Hawkmoths produce ultrasound to confuse bats.

Novel Mimicry Rings

• Moths have developed acoustical mimicry to confuse bats or avoid predation

Disappear

• Cloaking scales dramatically reduce bat detection.
• Moths or other insects can absorb sound.

Eat or be eaten

• Bats employ various tactics to evade predators when they cannot outfly.
• Strategy can involve unexpected flight directions, stealth, or fooling the bat using different wing shapes or structures to avoid attacks on the wrong part of an insect's body.
• Bats also use clicking or jamming as tactics for confusing bats to help confuse the bat about the insects location or to warn against the insects offensive chemical or noxious tastes.

Pollination Syndromes

• Bat pollination occurs in roughly 250 genera.
• Nectar bats are typically larger in mass and have longer jaws and are often found in dry environments

Bat Pollination

• Bat pollination has evolved independently in about 85 of these families.
• Pollination varies based on flower features and bat preferences.

Bats Diet-1 Pollination (Pollen & Nectar)

• Bats are vital for pollinating certain plants.
• Durian and Parkia are important fruits pollinated by bats,.
• Bats often pollinate plants with specific flower structures and scents.

1.5 X Body Length

• Some bat species have elongated bodies.

Diet and Physiology

• Multiple Bat species have different diets and physiologies.

Evolution and Selection

• Key genetic evolution in bats correlates with nectar consumption.
• 219 candidate genes are positively selected (p<0.05).

Synthesis

• Strong selective pressure, due to co-evolution, shapes bat features.
• This is manifested at multiple levels, including cellular level.
• Examples relating to co-evolution related to nectar or pollen consumption are prevalent in some ecosystems.