“…and today we’re talking about the world’s tiniest mammal. But more on that now.”
The smallest of sky-dwellers won’t win any contests of strength or speed, but hunting at night requires more precision than power. A sound in the forest will echo through the dark in a million directions, but a small source can create the right pitch to create pinpoint sonar. The bumblebee bat is as humble in it’s size as it is in it’s name but it has just the right fit to thrive in life, death and taxonomy.
Measure Up
Welcome to the beloved Measure Up segment. The official listener’s favorite part of the show! The part of the show when we present the animal’s size and dimension in relatable terms through a quiz that’s fun for the whole family. It’s also the part of the show that’s introduced by you when you send in audio of yourself saying, singing, or chittering the words Measure Up into ldtaxonomy at gmail dot com.
- Body Length: 1.1–1.3 inches (29–33 mm)
- Wingspan: 5.1–5.7 inches (130–145 mm)
- Weight: Approximately 1.7–2.0 grams (0.06–0.07 ounces)
Length of the Bumblebee Bat
The bumblebee bat has a body length of 1.3 inches (3.3 cm). How many objects fit into the bat’s length (if the object is shorter) or how many bats fit into the object’s length (if the object is longer)?
Question: How many fit into each length comparison?
A) 9.1 bumblebee bats go into the length of a Thai spirit house
B) 4.6 Myanmar jade beads go into the length of a bumblebee bat
C) 12.3 bumblebee bats go into the length of a Thai long-tailed boat propeller blade
a) The length of a Thai spirit house
A miniature Thai spirit house (san phra phum), found in Thailand to honor spirits, typically measures about 30 cm (0.3 meters or 11.8 inches) in height for a small household model.
b) The diameter of a Myanmar jade bead
A traditional Myanmar jade bead, used in jewelry, has a diameter of about 1 cm (10 mm or 0.39 inches) for a medium-sized piece.
c) The length of a Thai long-tailed boat propeller blade
A single propeller blade from a Thai long-tailed boat (rua hang yao), used on rivers like the Chao Phraya, measures about 50 cm (0.5 meters or 19.7 inches) for a standard craft.
Weight of the Bumblebee Bat
The bumblebee bat weighs 2 grams (0.002 kg). How many objects fit into the bat’s weight (if the object is lighter) or how many bats fit into the object’s weight (if the object is heavier)?
Question: How many fit into each weight comparison?
A) 25.0 bumblebee bats go into the weight of a Thai silk scarf
B) 6.0 Myanmar betel nuts go into the weight of a bumblebee bat
C) 3.0 bumblebee bats go into the weight of a Thai amulet
a) The weight of a Thai silk scarf
A lightweight Thai silk scarf, a cultural product from Thailand’s northeast, weighs about 50 grams (0.05 kg) for a small handwoven piece.
b) The weight of a Myanmar betel nut
A single betel nut (Areca catechu), chewed in Myanmar traditions, weighs about 1 gram (0.001 kg).
c) The weight of a Thai amulet
A small Thai Buddhist amulet (phra khruang), worn for protection, weighs about 10 grams (0.01 kg) for a clay or metal piece.
Major Fact: Tiny Bullseye
The bumblebee bat (Craseonycteris thonglongyai), has very precise echolocation– and it might be exactly because it’s so small.
High-Frequency Calls: Bumblebee bats emit ultrasonic calls in the range of 60–70 kHz, which are short-wavelength and ideal for detecting small objects like tiny insects (their primary prey) in dense forest environments. High frequencies provide finer resolution, allowing them to pinpoint prey as small as 1–2 mm.
Constant Frequency (CF) Echolocation: Unlike many bats that use frequency-modulated (FM) calls, bumblebee bats rely on CF calls, emitting a steady frequency for several milliseconds. This allows them to detect subtle Doppler shifts caused by the wingbeats of insects, enhancing precision in cluttered spaces like bamboo forests or limestone caves.
Small Body, Efficient Sound Production
Their tiny larynx and vocal structures are optimized for producing intense, focused sound pulses despite their 2-gram size. This efficiency ensures strong echo returns, critical for navigating and hunting in complex habitats.
Sensitive Hearing: Their large ears (relative to body size) and specialized auditory system are tuned to detect faint echoes from small targets. The cochlea is highly sensitive to their specific call frequencies, filtering out irrelevant noise.
Rapid Call Rate: Bumblebee bats emit calls at a high repetition rate (up to 200 pulses per second during hunting), allowing real-time updates on prey location and movement. This rapid feedback loop is crucial for tracking fast-moving insects in tight spaces.
Environmental Adaptation: Living in dense forests and caves in Thailand and Myanmar, their echolocation is fine-tuned for short-range detection (a few meters), prioritizing precision over distance. This suits their niche of hunting small insects in cluttered environments.