Mouse spiders!
There are eight species of mouse spiders in Australia and they are widely
distributed across the mainland.
There are eight species of mouse spiders in Australia and they are
widely distributed across the mainland. They vary from 10 mm - 35 mm body length
and all have distinctively bulbous head and jaw regions. They are often confused
with funnel-web spiders. While mouse spider bites are not common, a few have
caused serious effects in humans, with symptoms similar to funnel-web spider
envenomation. Fortunately, mouse spiders are not usually abundant in heavily
populated urban areas.
Identifying mouse spiders
The following key features distinguish the mouse spiders from other large
black spiders:
Suspects gallery
Mouse spider species are often mistaken for funnel-web spiders. Both can be
large and shiny black. Compare these images and spot the differences.
However, the burrow's most unusual feature are the two surface trapdoors set
almost at right angles to each other. The silk and soil trapdoors often merge
well with the ground, making them hard to see (and increasing the impression of
scattered rather than aggregated burrow sites, making accurate estimates of
their abundance difficult). They may be thin and wafer-like or thick and
plug-like. Having two doors probably increases both prey catching area and
efficiency. A few silk triplines may extend outwards from the entrances. These
can help alert the spider to approaching prey or male spiders and also help with
surface navigation while hunting. Prey is usually ambushed from within the
safety of the trapdoor 'hides', but mouse spiders have been observed foraging
outside the burrow at night. With their powerful jaws and venom, they can tackle
prey ranging from ants, beetles and spiders to small lizards and frogs.
Little is known about the burrows of other species. The forest dwelling
Eastern Mouse Spider appears to have a single, flap-like door and a shallow
burrow with a side chamber. Unlike other species, this mouse spider has
occasionally been reported living in large aggregations. Recently, almost 300
specimens were collected from the backyard of a house on the central coast of
New South Wales after flooding rains drove the animals from their burrows.
Daytime wanderers
Most male mygalomorph spiders wander by night in search of females during
their mating season. This is to avoid both day-active predators and excessive
heat and water loss. However, the males of several mouse spider species can be
seen wandering about by day during the late summer to early winter months
(especially after rain), the mouse spider mating season. These daytime wanderers
are unique in having distinctive body colour patterns. Eastern Mouse Spider
males (Missulena bradleyi) from eastern Australia have a blue/white
patch on the front of the abdomen. In M. pruinosa from northern
Australia, this patch is yellowish-cream and spreads over much of the abdomen.
These spiders live in open forest habitats where their pale blue and
yellow/cream patches may help them blend in with the dappled shading of the
forest floor, perhaps making them difficult for predators to see.
Most arresting are the males of the Red-headed Mouse Spider (M.
occatoria) which ranges across semi-arid Australia. These males have a
bright reddish-orange head and jaw region and the abdomen has a gunmetal blue
tinge. In open woodland and shrubland habitats this pattern may act as both
warning and disruptive colouration, deterring some predators and avoiding others
by blending in with the sharply shadowed soil and litter background.
By contrast, little is known about the wandering behaviour of some small,
forest dwelling mouse spider species that are entirely black in colour.
distributed across the mainland.
There are eight species of mouse spiders in Australia and they are
widely distributed across the mainland. They vary from 10 mm - 35 mm body length
and all have distinctively bulbous head and jaw regions. They are often confused
with funnel-web spiders. While mouse spider bites are not common, a few have
caused serious effects in humans, with symptoms similar to funnel-web spider
envenomation. Fortunately, mouse spiders are not usually abundant in heavily
populated urban areas.
Identifying mouse spiders
- Mouse spiders have high, bulbous heads and jaws
- The carapace is smooth and shiny
- The eyes are spread across the front of the carapace, not closely
grouped - The spinnerets are short, the last segment domed and button-like
- Male spiders have long slender pedipalps
- Male spiders have no mating spurs on the legs
- Males of some species have distinctive colour markings but others are black
overall
The following key features distinguish the mouse spiders from other large
black spiders:
- bulbous head and jaws
- shiny carapace
- eyes spread across front of carapace
- short spinnerets
Suspects gallery
Mouse spider species are often mistaken for funnel-web spiders. Both can be
large and shiny black. Compare these images and spot the differences.
However, the burrow's most unusual feature are the two surface trapdoors set
almost at right angles to each other. The silk and soil trapdoors often merge
well with the ground, making them hard to see (and increasing the impression of
scattered rather than aggregated burrow sites, making accurate estimates of
their abundance difficult). They may be thin and wafer-like or thick and
plug-like. Having two doors probably increases both prey catching area and
efficiency. A few silk triplines may extend outwards from the entrances. These
can help alert the spider to approaching prey or male spiders and also help with
surface navigation while hunting. Prey is usually ambushed from within the
safety of the trapdoor 'hides', but mouse spiders have been observed foraging
outside the burrow at night. With their powerful jaws and venom, they can tackle
prey ranging from ants, beetles and spiders to small lizards and frogs.
Little is known about the burrows of other species. The forest dwelling
Eastern Mouse Spider appears to have a single, flap-like door and a shallow
burrow with a side chamber. Unlike other species, this mouse spider has
occasionally been reported living in large aggregations. Recently, almost 300
specimens were collected from the backyard of a house on the central coast of
New South Wales after flooding rains drove the animals from their burrows.
Daytime wanderers
Most male mygalomorph spiders wander by night in search of females during
their mating season. This is to avoid both day-active predators and excessive
heat and water loss. However, the males of several mouse spider species can be
seen wandering about by day during the late summer to early winter months
(especially after rain), the mouse spider mating season. These daytime wanderers
are unique in having distinctive body colour patterns. Eastern Mouse Spider
males (Missulena bradleyi) from eastern Australia have a blue/white
patch on the front of the abdomen. In M. pruinosa from northern
Australia, this patch is yellowish-cream and spreads over much of the abdomen.
These spiders live in open forest habitats where their pale blue and
yellow/cream patches may help them blend in with the dappled shading of the
forest floor, perhaps making them difficult for predators to see.
Most arresting are the males of the Red-headed Mouse Spider (M.
occatoria) which ranges across semi-arid Australia. These males have a
bright reddish-orange head and jaw region and the abdomen has a gunmetal blue
tinge. In open woodland and shrubland habitats this pattern may act as both
warning and disruptive colouration, deterring some predators and avoiding others
by blending in with the sharply shadowed soil and litter background.
By contrast, little is known about the wandering behaviour of some small,
forest dwelling mouse spider species that are entirely black in colour.