Home / Orb Weavers / Bird-dropping (Celaenia excavate)

Bird-dropping (Celaenia excavate)

Bird-dropping spiders indigenous to Australia belong to the orb-weaver family. They are named so because of their large size, and a color pattern closely similar to that of a bird’s dropping. Apart from these, there are other species too like those of the Mastophora genus that also bear a resemblance to bird droppings.

Bird Dropping Spider

Physical Description and Identification

Adults

Size: The females are 0.47 inches (12mm) long, while the males are shorter and have a body length of not more than 0.09 inches (2.5 mm).

Bird Dropping Spider Size

Color: They have a pale white, black, and grey coloration likened to a bird’s dropping, as mentioned above.

Other Characteristic Features: These spiders possess a large, broad triangular-shaped abdomen, being concave along the midline. It also has long, spiny forelegs. When at rest, the legs remain folded against their body.

Eggs

The females produce about 13 egg sacs with each containing 200 eggs on an average. The egg sacs look like marble-shaped brown balls, having a diameter of 0.47 inches (12 mm), held together with strong thread-like structures.

Bird Dropping Spider Eggs

Spiderlings

The spiderlings emerging from the sacs have a pale color at the beginning that darkens as they mature.

The Web

Only the young bird-dropping spider makes circular webs. The females do not spin webs and have a different strategy of capturing their prey. They hang from a leaf upside down, waiting for the moth to come, and the moment it does, they seize it with their sturdy legs.

Are Bird-dropping Spiders Venomous

Not much is known about their levels of toxicity, but their venom is not considered dangerous to humans. Their bite often leads to minor swelling or redness that could heal with first aid.

Bird Dropping Spider Image

Quick Facts

Other NamesOrchard Spider, Death’s Head Spider,
DistributionEastern, southern, and central parts of Australia
HabitatForests, wetlands, heath, woodlands, as well as orchards and gardens (sitting on fruit trees)
PredatorsBirds and wasps
DietInsects, mainly moths
Lifespan1 year

Did You Know

  • The markings on their body often look like a skull, giving them the name Death’s Head Spider. On the other hand, many call them Orchard Spiders as they are spotted on fruit trees waiting for their main prey, the moth.
  • They follow the mimicking strategy by releasing pheromones that mimic the female moth’s odor, to get hold of their prey.

Image Source: Brisbaneinsects.com, Knowledgebase.lookseek.com, Jennifermarohasy.com, Static.inaturalist.org

Bird-dropping spiders indigenous to Australia belong to the orb-weaver family. They are named so because of their large size, and a color pattern closely similar to that of a bird’s dropping. Apart from these, there are other species too like those of the Mastophora genus that also bear a resemblance to bird droppings.

Bird Dropping Spider

Physical Description and Identification

Adults

Size: The females are 0.47 inches (12mm) long, while the males are shorter and have a body length of not more than 0.09 inches (2.5 mm).

Bird Dropping Spider Size

Color: They have a pale white, black, and grey coloration likened to a bird’s dropping, as mentioned above.

Other Characteristic Features: These spiders possess a large, broad triangular-shaped abdomen, being concave along the midline. It also has long, spiny forelegs. When at rest, the legs remain folded against their body.

Eggs

The females produce about 13 egg sacs with each containing 200 eggs on an average. The egg sacs look like marble-shaped brown balls, having a diameter of 0.47 inches (12 mm), held together with strong thread-like structures.

Bird Dropping Spider Eggs

Spiderlings

The spiderlings emerging from the sacs have a pale color at the beginning that darkens as they mature.

The Web

Only the young bird-dropping spider makes circular webs. The females do not spin webs and have a different strategy of capturing their prey. They hang from a leaf upside down, waiting for the moth to come, and the moment it does, they seize it with their sturdy legs.

Are Bird-dropping Spiders Venomous

Not much is known about their levels of toxicity, but their venom is not considered dangerous to humans. Their bite often leads to minor swelling or redness that could heal with first aid.

Bird Dropping Spider Image

Quick Facts

Other NamesOrchard Spider, Death’s Head Spider,
DistributionEastern, southern, and central parts of Australia
HabitatForests, wetlands, heath, woodlands, as well as orchards and gardens (sitting on fruit trees)
PredatorsBirds and wasps
DietInsects, mainly moths
Lifespan1 year

Did You Know

  • The markings on their body often look like a skull, giving them the name Death’s Head Spider. On the other hand, many call them Orchard Spiders as they are spotted on fruit trees waiting for their main prey, the moth.
  • They follow the mimicking strategy by releasing pheromones that mimic the female moth’s odor, to get hold of their prey.

Image Source: Brisbaneinsects.com, Knowledgebase.lookseek.com, Jennifermarohasy.com, Static.inaturalist.org

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