Last week featured a wide range of animal stories that either made us smile or have a little giggle. We’ve rounded them all up for your Monday morning.
A hole new image
If you’re interested in how a dinosaur poops, researchers have described (in explicit detail) a Psittacosaurus cloaca; the multipurpose opening some animals use for pooping, peeing, laying eggs, and sex.
The team, led by Jakob Vinther from the University of Bristol, England, noticed the cloaca of the Labrador-sized dinosaur was reminiscent of crocodiles, and may even have had similar musky scent glands. But they also might have been highly pigmented with melanin as a colour signal, like with baboon bottoms.
Birds also have a cloaca, so this suggests the opening dates all the way back to dinosaur ancestors from the Mesozoic.
“Knowing that at least some dinosaurs were signalling to each other gives palaeoartists exciting freedom to speculate on a whole variety of now plausible interactions during dinosaur courtship,” says Robert Nicholls from the University of Massachusetts Amherst, another author of the pooper paper. “It is a game-changer!”
Elderly birds tweet for help from babysitters
It turns out that it’s not only human parents who enlist help to look after their young. Infant Seychelles warblers (Acrocephalus sechellensis) fare better if their elderly parents have help raising them.
Seychelles warblers are a cooperative breeding species that live in small family groups, sharing the care of young between parents and “helpers”.
The study from the University of East Anglia (UEA) and the University of Groningen found that this team-effort can compensate for a decline in the elderly parents’ ability to provide sufficient care.
Researchers used data collected across 30 years on the warblers on Cousin Island, a tiny island in the Seychelles. They found that the care of offspring is often shared between the dominant breeding pair and a variable number of adult helpers that assist with various tasks including providing food for the offspring.
“The amount of care that dominant breeders provide is reduced when they are assisted by helpers and this lower parental investment can improve the parents’ own survival and future reproductive output,” says senior author David S Richardson from UEA.
The work is published in the journal Evolution Letters.
Stand clear of cobra spit
Venom from spitting cobra species evolved to cause immense pain as a form of self-defence, rather than for capturing prey.
An international team, including researchers from the University of Queensland (UQ), studied the composition of spitting cobra venoms from three groups – Asian spitting cobras, African spitting cobras and Rinkhals.
“We tested how venom components affected pain-sensing nerves and showed that spitting cobra venoms are more effective at causing pain than their non-spitting counterparts,” explains co-author Irina Vetter from UQ’s Institute for Molecular Bioscience.
The researchers suggest the snakes had independently evolved the ability to spit the venom. The three different groups of snakes were found to have increased production of an enzyme toxin called phospholipase-A2, which works cooperatively with other venom toxins to maximise pain.
And while rather fascinating, the researchers say the findings are also helpful in the development of more effective painkilling drugs.
“Pain-causing toxins from animal venoms can be useful tools to help us understand pain signalling at a molecular level and are helping us to identify new targets for future painkillers,” says co-author Sam Robinson from UQ.
The work is published in the journal Science.
No shame for ancient bug
An assassin bug fossil has been assembled with an extremely well-preserved genital capsule – called a pygophore.
The fossil was found in 2006 but was accidentally cracked. The poor bug’s manhood was split down the middle and the separate halves were sold.
Now that they have been reunited, Sam Heads at the Illinois Natural History Survey and Daniel Swanson of the University of Illinois Urbana-Champaign have identified a basal plate; a hard, stirrup-shaped structure that supports the bug’s member.
It also appeared to have a small phallus pouch, into which the little guy withdrew “himself”.
“To see these fine structures in the internal genitalia is a rare treat,” says Swanson. “Normally, we only get this level of detail in species that are living today.”
The bug has been named Aphelicophontes danjuddi after a fossil collector who donated half the specimen.
You can see the detail in their paper, published in Papers in Palaeontology.
Praying mantis fight to the death
The praying mantis has quite a reputation for cannibalism, with females often eating males before they get the chance to mate. However, males of one species in particular, the springbok mantis (Miomantis caffra), are starting to fight back.
Researchers from the University of Auckland and the University of New South Wales have found that before mating, male and female springbok mantises wrestle in a violent struggle, with each partner trying to be the first to grasp hold of the other with their front legs.
Credit: Dr Nathan W Burke
If the female wins, it’s game over for the male, leading to almost certain death by cannibalism. However, if the male wins, they dramatically increase their chances of successfully mating, while also injuring the female in the process and escaping to live another day.
“The intimidatory and injurious nature of male wrestling behaviour suggests it is a form of sexual coercion by which males compel females to mate,” the authors write in their paper published in Biology Letters.
“Miomantis caffra males are known to approach females cautiously and attend to different social and ecological cues simultaneously when deciding when to initiate mating attempts. This suggests that harmful coercion could be one of a suite of possible mating tactics that males employ in different contexts.”