Bats Flashcards
Where can you find bats around the world?
every environment except oceans and polar regions covered in ice
Can bats fly
yes, only mammal that can truly fly
what portion do bats take of mammalian species?
1/2
1/4
1/8
3/4
1/4
What foraging guilds do bats species consume?
nectar
fruit
vertebrates (fish)
arthropods
blood (neotropics)
What is the name of the bat that consumes blood?
name
family
and where does it occur
Common vampire bat
Desmodos retundus
Family: Phyllostomidae
occurs throughout central and south america
Sharp incisors - pierces skin.
In relation to bats, what is the
Phylum:
Subphylum:
Class:
Order:
Chordata
vertebrata
Mammalia
Chiroptera
Chiro “hand: tera “wing”
What similarities do australian bats have to humans/mammals?
Their latin name means;
Chiro “hand: tera “wing”
They have a bone in the wing that is similar to human hands and arms.
a humerus, radius, ulna bone, wrist and digits (proportionally the digits are longer and support wing function)
What are the two main suborders for bats?
- Yinpterochiroptera
- Yangochiroptera
What are the family names in
Yinpgterochiroptera and how are they charactrised?
Pteropodidae - fruit bats flying foxes (big) - no echolocation
Group as weird (below) - echolocation, specialised
Megadermatidae
Rhinolophidae
Hipposideridae
Rhinonycteridae
What are the family names in Yangochiroptera and how are they mainly characterised?
Characterised as very small
echolocation
Emballonuridae
Molossidae
Miniopteridae
Vespertilionidae
What is echolocation
the sound bats use to navigate by generate high fequency sound by the larynx - emitted from the mouth or nose
gaining information from the sounds, such as distance and how fast an object is moving
Why are there different types of echolocation within the subgroups of bats?
Echolocation has evolved over time - this is why they have different forms within the yinpetrochiropteran and yangchiropteran bats
What are species types in the Pteropodidae?`
Larger bats/ no echolocation (Exceptions in asia/africa)
Pteropus: Flying fox/ fruit bat
macroglossus
syconycteris
nyctimene
dobsonia
What family do flying fox/fruits bat belong to?
Pteropodidae
What are three types of Pteropodidae - Pteropus?
- Black flying fox (north eastern australia)
black with red or orange on the back of neck
long snout
dur does not extend to feet - grey-headed flying fox (south-eastern)
round, grey face with short ears
fur extends to the feet on the back of legs
vulnerable - little red flying (smallest of the bats)
reddish brown
large ears
What diverse foraging guild strategy do little red flying bats have in particular?
with satellite tracking data, the most nomadic of australia flying foxes - tracking food as it become available due to the diverse climate in Australia.
They are good at adapting food
Very social animals - travel together to different area
204 different plant species from a study done, corymbia, eucalyptus and melaleuca drive mass aggregations - tongue morphology to enhance nectar harvesting
What is Australian insectivores bat?
In the yinpterochiroptera, Megadermatidae - Ghost bat
very distinct echolocation
ears are design for echolocation
What are the characteristics of the Yangochiroptera that can assist in telling them apart, and what is a factor they have in common?
Echolocation is a factor they have in common
Their tails are different sizes
How do you identify a bat from sound?
Can record the sound to show a sonogram
* Sonogram: a graph representing a sound, showing the distribution of energy at different frequencies.
* E.g. frequency over time
distinct - record the sound on a sonogram, and look at the characteristics (echocate between 8 and 200 Hz.
search phase -
attack phase (more information)
what type of bat calls do you get? Compare high duty and low duty cycle?
Yinpterochiroptera: high duty cycle
* Use constant frequency (CF) echolocation narrowband
* Detect sudden changes in echo amplitude and doppler shifts induced by wing fluttering of insects
– Most effective in cluttered habitats
– Useful for target detection (e.g. prey)
Yangochiroptera: low duty cycle echolocators: brief calls with gaps for
listening to echoes
* Use frequency modulated (FM) (frequency changes as a downward
sweep over time) broadband
* Useful for target (e.g. prey localisation)
And a few in between (called CF-FM or FM-CF)
How do bats call vary within species?
depending on what they are doing - Bat calls vary within species depending on:
echolocation is depending on spatial context - changing it on the circumstances.
– Activity (e.g. feeding, communicating with each other, flying freely)
– Habitat (within canopy vs open areas)
– The direction of flight from microphone (e.g. doppler effect)
– general Conditions with affect bats ability to echolocate– heat, humidity, wind - atmosphere plays apart in sound projection
– Geographic location – populations vary over space, bats call vary depending what population they come from. Likely to shift the amount of sound space, depending on who is using it.
– Other species present
- Bats shift their calls if there are other bats nearby to avoid confusion
What properties used differ the echolocation call type?
High frequencies =
– More detail
– Higher attenuation over space
Low frequencies = travel further but give;
– Less detail
– Travel further
* “Sweeping” calls across many frequencies
what factors play a role in how bats fly?
- Echolocation call type – very important; also
- Wing morphology
How does wing morphology affect the flight?
related to how much energy goes into how much flapping will occur
Puts mechanical & energetic constraints on
flight behaviour
- Depends on size of bat, size and shape of
wings relative to body weight - Metrics:
– Wing loading: weight/wing area (how much load per wing are)
– Aspect ratio: wingspan^2/wing area
– Wingtip shape index: ratio of handwing:armwing
How do bats have have a Manoeuvrable type of flight?
Low wing loading (light weight compared to wing
area)
* Low aspect ratio (broad wings)
* Short, rounded wingtips
energetically expensive
narrow wings
How do bats have a fast flight type of flight?
High aspect ratio (narrow wings)
Pointed wingtips
low cost and low manoeuvrability
long wings
How is foraging strategy influence?
Wing morphology
– Ratios of weight, wing area, wing length
– Determine manoeuvrability, energetic cost of
flight
* Echolocation call type
– High and low frequencies
– Frequency modulated vs. constant frequencies
If a bat was in a tropical rainforest, what adaptations would be suited for the bat?
- Above and 2. Below the forest.
Small and manoeuvrability.
- Echolocation & flight strategies:
– high frequency, constant frequency echolocation which gives good detail of clutter, high attenuation; manoeuvrable species - – above-canopy fast-flyers: lower frequencies, frequency modulated echolocation = poorer detail of clutter, low attenuation
Foraging guilds:
-Fruit eaters
-Nectar eaters
-Lots of insectivores
What are a few examples of tropical rainforest bats?
Tube nose bats - Nyctimene robinsoni
Eastern blossom bat - Syconycteris australis
Long eared bats - Nyctophilus spp.
What is a bat that is known to fly above the canopies of the rainforest?
Chaerephon jobensis – northern freetail bat
Low frequency; frequency modulated
What is a bat that is best adapted to dense rainforest?
Rhinolophus megaphyllus – eastern horseshoe bat
High frequency (60-70 kHz); constant frequency call
What bat would best survive in a savannah/woodlands open forest?
Intermediate foraging strategy:
– Some manoeuvrability
– Mid-range echolocation
Also high fast flyers using low frequencies
Mostly insectivores
What bat would best survive in savannah/woolands?
Scotorepens balstoni
What happens if the habitat structure changes due to fire?
Bats response to fire, rhinolophus megaphyllus (below canpoy) and saccolaimis spp (below)
bats increased activity after fire, more space and insects available.
The structure of the bat community changed following fire- the overall bat activity
Sacc sp became more active post-fire
R.meg found to be fire insensitive (clutter tolerant but not restricted)
How are caves important to Australian bats? and what are the requirements to bats in the caves?
Overall, most bats in australia use tree hollows, and rooves, boulders, under overhangs
only small number of species roost in caves.
Cave species have narrower temperature and
humidity requirements
-> cave specialists
Large communal roosts
Large maternity colonies
long lived and slow reproduction
What species are found in caves?
Horseshoe bats Rhinolophus spp
Ghost Bats Macroderma gigasBentwing bats Miniopterus spp.
What special adaptation do miniopterus spp have for caves?
Bentwing bats - miniopterus spp.
A cave bat, their wing tip has an extra fold that’s extra long.
They can have a point wing-tip that can expand, allowing them to have a high fast fliers, with low energetic cost - most likely to allow them to travel from cave to cave.
protect the the long tip by tucking it in.
What makes the southern bent-wing bat critically endangered?
Because they only have 3 caves they reside in australia, reproducing in one cave. Naracoorte bat cave.
48 overwintering caves identified - they topor in these caves during winter, reducing use of energy.
What are threats against the southern bent wing bat?
Habitat loss – 90% of native veg in their range has been cleared
Drought - fruit supply and survivorship
Maternity roost disturbance or damage - wipe out breeding for the year.
Disturbance during torpor -
Windfarms - not conclusive yet
Pesticide- reducing food avaliable
What is one of two mammals that have gone extinct in recent Australian history?
and what threats did they have?
Christmas island pipstrelle - Pipistrellus murrayi)
- Endemic to Christmas Island (Australian territory)
- Surveys from 1994 – 2005 showed steep decline, disappearing from
parts of the island
Yellow crazy ants
- Common wolf snake
- Black rats
- Feral cats
- Giant centipedes
Habitat loss
What efforts are being made for bats conservation?
Threats include:
* Habitat modification
– e.g. urbanisation, agricultural land
– Changes food availability (e.g. Fruit trees, agricultural
pests)
* Loss of roosts
– Hollow trees
– Disturbance in caves
– Mining activity
What are threats towards bat conservation?
- Climate change -
– Species with narrow temperature & humidity tolerances such as black flying fox
– Shifting climate envelopes & species
– Changing food availability - Human conflict
– lychee farmers, large roosts in urban areas, concern &
paranoia of disease
