Lizards of Oz take toll on turtle eggs

Date:  December 14, 2017

Source:  University of Queensland

Summary:

Goannas have overtaken foxes as the number one predator of the endangered loggerhead turtle at its second largest Queensland nesting beach. A new study has found that since feral red foxes were controlled in the 1980s, there has been an increase in the number goanna raids on loggerhead turtle nests at Wreck Rock beach, south of Agnes Waters.

Continued  

Shell-swinging snails knock out predators

Date:November 16, 2016

Source:Hokkaido University


Researchers in Japan and Russia have found some snail species that counterattack predators by swinging their shells, suggesting the importance of predator-prey interactions in animal evolution.

Until now, snails were thought to protectively withdraw into their shells when attacked. However, an international research team has found a pair of snail species that use their shells like a club to hit predators and knock them over.

Evolutionary scientists have been questioning how predator-prey interactions affect the evolution of the prey. However, they are yet to resolve whether this interaction induces the diversification of the prey species and its morphological features and behaviours, and if so, why?

Researchers from Japan's Hokkaido University and Tohoku University collaborated with colleagues at the Russian Academy of Sciences to closely study snail species from the genus Karaftohelix in both countries. They observed each species' defensive behaviours against their predator, the carabid beetle, and conducted shell measurements and species comparisons. The team used DNA sequencing to analyse how closely related the species were to each other.

Read on

Lionfish Predation Habits And Ideal Prey Analyzed In New Study

Brett Smith for redOrbit.com – Your Universe Online

Majestic lionfish have been spotted in the Caribbean and Atlantic since the 1980s and these invasive fish have a reputation for ferocious predation and rapid expansion.

Now, a new study by researchers from Oregon State University and Simon Fraser University in Canada has revealed details surrounding the lionfish’s predation habits and ideal prey.

“With species now moving all over the world in both marine and terrestrial systems, we need to know who will eat whom when species encounter each other for the first time,” said study author Stephanie Green, a research fellow in the OSU College of Science.

“Normally, predator-prey experiments take a lot of effort and time,” Green said. “But there are mathematical techniques that can help us better understand what is happening when we observe animals hunting in the wild, and why some species get eaten and others don’t.”

Published in the Journal of Animal Ecology, the new study reveals that the lionfish’s ideal prey is a small, solitary fish with a long, skinny body situated near the seafloor.

By analyzing studies on the observations of lionfish predation and the stomach contents of these fish, the study team was successfully able to identify what traits all lionfish prey tend to have in common.

Read more at

Tree frogs speed up their life cycle when becoming lunch

Date:

September 3, 2014

Source:

Springer

Think again if you've always believed that events in the life cycle of animals happen consistently, almost rigidly, as part of the natural rhythm of nature. Studies by Sinlan Poo and David Bickford of the National University of Singapore, Singapore, show that Mother Nature is much more flexible than you might think. In a paper in Springer's journalBehavioral Ecology and Sociobiology, the researchers describe how Hansen's tree frog (Chiromantis hansenae) speeds up its life cycle to hatch earlier once its eggs are preyed upon.

Read more ...

Cheetah study gets lions off the hook

Cheetahs have a hard life on the Serengeti plains. Less than 5% of cubs will survive into adolescence and a previous study puts predation by lions as one of the biggest threats to cheetah cubs. A new study on cheetah cubs in the Kgalagadi Transfrontier Park suggests that the low survival rates of the Serengeti may not be the norm of cubs and lions may not be the big threat that they are currently considered to be.

The high levels of predation by lions of cheetah cubs in the Serengeti makes some conservationists believe that the two big cats would have difficulty surviving together within conservation areas. The Serengeti study followed 125 cheetah cubs from den to adolescence and only 4.8% survived. This low-level of survival has been considered in conservation policies and strategy with some concluding that the two can not successfully co-exist in defined protected areas.

Continued

Water voles 'decline by a fifth'

Water voles have declined by a fifth in the UK since 2011, a survey suggests.

Conservationists say that habitat loss, predation by American mink, and changeable weather are to blame.

The research was carried out by the Environment Agency and Wildlife Trusts, who are working to create more vole-friendly waterways.

Earlier reports had suggested that the animals were making a comeback. Conservationists say more needs to be done to save this species.

Alastair Driver, National Conservation Manager from the Environment Agency, said: "This creature is part of our waterway systems. People love walking along a canal and hearing the plop of a water vole into the canal. They are part of the food chain... part of the ecosystem.

"It would be a real shame to let that go."

'Ratty'

Water voles, immortalised by Ratty from Wind in the Willows, were once a common sight in the UK's waterways.

But since the 1970s, water vole numbers are thought to have declined by more than 90%.

Continued

Osprey chick snatched by buzzard raises one-eyed questions

One-eyed view on buzzards and a coiincidence
July 2012. This remarkable video clip was filmed on a nest cam in Scotland. The clip shows an osprey leving her nest moments before a buzzard swoops down and carries off one of the chicks. This provoked some very strange reactions from certain sections of Scottish society, howling about the danger of buzzards to rare spoecies.

THE STORY HAS SOME INTERESTING ASPECTS THOUGH:

The film was taken at Lochter, a custom made fishing and outdoor pursuits centre run by Euan Webster. Mr Webster is "a former chairman of the Game & Wildlife Conservation Trust's Grampian regional group". Various groups have ben howling about the need to control buzzards for persecuting ospreys, and, according to a statement made via Scottish Land and Estates, Mr Webster states He said: "This was a shocking act and clearly demonstrates why something needs to be done to control buzzards. It cannot be right that the buzzard remains protected yet they swarm over the countryside in large numbers eating prey - including iconic and beautiful birds such as Ospreys - at will."

Scottish Land and Estates statment also states "As Buzzard numbers have grown, clearly there is a need for increasing amounts of prey for them to eat. Whilst smaller populations of Buzzards may at one time have been able to survive mostly on carrion, rabbits and small game, this is now clearly not the case with growing numbers of reports of Buzzards preying on other wildlife such as red squirrels and other wild birds, some of them being rare species of conservation concern such as Osprey."

This ignores some facts; Ospreys have coexisted very happily with buzzards for centuries, until human intervention removed them from the scene in the UK. Buzzard numbers too are now reaching healthy, and probably natural, levels since their persecution was stopped (or slowed at any rate) and various chemicals have been removed from the countryside.

Do buzzards kill other birds for fun? Now that would be shocking behaviour
What was so shocking about a raptor catching and eating something? One would have thought that someone in Mr Webster's position would have known that this happens occasionally. What would have been shocking would be if the buzzard had killed another bird just for the fun of it - Or even charged another buzzard for the right to do that on his patch.

Continued:  http://www.wildlifeextra.com/go/news/osprey-buzzard.html#cr

Giant Insects Shrunk As Birds Entered Prehistoric Skies

Millions of years ago, oversized insects like griffinflies boasting wingspans comparable to today's hawks scuttled across (and fluttered above) the planet. But why these jumbo jets of the insect world shrunk to modern size has remained a mystery, until now.

Turns out, as dinosaurs evolved flight and eventually took to the skies as birds, they beat down the huge insects already living there, effectively putting a cap on insect size through predation and competition in the prehistoric skies, as birds developed into sophisticated flying machines.  

"The change in insect size is gradual," study researcher Matthew Clapham, of the University of California, at Santa Cruz, told LiveScience. "This gradual change fits quite nicely with the gradual evolution in birds at the time."

Continued:  http://www.livescience.com/20735-giant-insects-shrunk.html

Snail that eats crabs in Queensland

Eats prey larger than itself! - See more details on 'Sciencey thoughts' blogspot

March 2012. A voracious predator that devours prey larger than itself has been found lurking beneath Queensland's golden sandy beaches.

Waves of scurrying blue soldier crabs are a common sight on the sand and mud flats of Moreton Bay near Brisbane and new research led by Dr Thomas Huelsken, from The University of Queensland's (UQ) School of Biological Sciences, has found these crabs have a good reason to stay on the move.

Dr Huelsken has discovered the Australian endemic moon snail, Conuber sordidus, can surge up out of the sand to grab fast moving soldier crabs. Some of the crabs caught are larger than the attacking snail. Capturing this behaviour on film for the first time, Dr Huelsken said the beautiful polished shells of moon snails belie their nature as vicious predators.

Dr Huelsken said "Moon snails are well known for attacking other snails and bivalves and until now, moon snails have been thought to feed almost exclusively on shelled molluscs. This observation that they also prey on crabs is a total surprise. Moon snails have now secured their status as top predators of the intertidal sand flats."

Drill through the crabs shells
Dr Huelsken said the slow-moving moon snails typically creep up on other molluscs, and upon reaching their prey, drill through their victim's shell, eating them alive through the hole.

"Many beaches have a littering of empty shells that have perfect round holes left by an attacking moon snail. These empty shells provide important clues for palaeontologists who are studying how prehistoric molluscs interacted with each other and their environment," Dr Huelsken said.

"Moon snails were thought to exclusively eat other molluscs and have left clear evidence of their attack on the remaining shells. They have been important scientific models for understanding past predator-prey interactions. Now, we can surmise that palaeo moon snails were probably eating crabs too, but have somehow not left a fossil record for that part of their diet."

"This means that the fossil record of moon snail predation may not be as complete as previously believed."

http://www.wildlifeextra.com/go/news/moon-snail.html