Tag Archives: animals

Counting Chicks

16 Thursday Apr 2015

Posted by in Birds, Evolution, Mind

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Chick and Tilda, its mother (photo © and courtesy of Hannele Luhtasela-El Showk)It’s probably not a surprise that humans aren’t the only animals with a sense of numbers. While they’re probably not actually counting, a variety of species seem to be able to tell the number of objects in a group; they can distinguish between groups with greater or fewer objects and react with surprise when the number changes unexpectedly. However, a recent study suggests that this numerical understanding may go deeper than we’ve previously thought. Continue reading →

The Ten-legged Spider

18 Friday Jul 2014

Posted by in Arthropods

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Every word in the title is a lie. The creature I’d like to introduce isn’t a spider and it doesn’t have ten legs, but that was exactly what I thought when I got a good look at it, which wasn’t the first time I saw it. The first time I saw it, I thought it might have been a plant’s root or some kind of stolon. I had just jumped in for a swim on Saturday afternoon when I saw something brown at the bottom of the pool. It wasn’t moving, and it seemed to be about the size of my thumb. Grabbing the sieve, I dived down and fished it out, then called my partner over. “Can you have a better look at this and see what it is? I think it’s some kind of root, but I can’t really see it properly.” My long, wet hair was obscuring my vision and I was trying to keep the sieve above water.

“It’s a spider,” she said. “A gigantic spider!” (It was gigantic — around 8-9cm across!) I’m lucky enough to be married to someone with a fascination for creepy-crawlies; with a smile, she deposited the dead spider in a jar for later examination and then joined me in the pool. Continue reading →

How Some Critters Evolved to Eat Poison

12 Thursday Jun 2014

Posted by in Arthropods, Evolution, Insects, Plants

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Since plants generally can’t move around, they have to rely on other strategies to cope with animals eager to turn them into a meal. Chemical weapons are a significant part of plants’ defensive arsenal. For example, thousands of plant species produce precursors of the deadly poison hydrogen cyanide; when an animal eats the plant, the precursors get converted into cyanide, which kills the offending animal. Continue reading →

The give-and-take between mothers and their offspring

27 Tuesday May 2014

Posted by in Development, Evolution, Genetics

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Image credit: Flickr user nekrumThis is a story about a gene which makes nursing mice produce more nutritious milk while also making their offspring less demanding. The gene serves to balance nutrient supply and demand between the mother and pup. If the gene is knocked out, the mother’s milk is less rich, but the pups are more demanding, evening out the impact. Things only go wrong when there’s a mismatch. If pups with a defective copy of the gene feed from a normal mother, their increased demand makes them grow larger than normal. Conversely, pups with a good copy end up smaller if they feed from a mother lacking a working copy, since her milk is less nutritious. Continue reading →

The Right Way to Fall

07 Wednesday May 2014

Posted by in Links, Mammals

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My latest story on Beacon is about how cats and other animals manage to always land on their feet. It turns out to be a pretty impressive maneuver, and geckos have evolved and entirely different trick to accomplish the same thing:

There’s no need to go far afield to find wonders of the natural world; sometimes it just takes a shift of perspective to notice how they abound in our homes and neighborhoods. Cats, for example, are exquisite animals, with an uncanny ability to take a fall harmlessly by righting themselves in midair. Several years ago, my cat slipped off a sixth-storey ledge, falling something like 20 meters onto hard concrete. She was limping for a few weeks, but her knee healed and there’s no sign of the injury left. How cats manage such a feat is a question which has occupied scientists for over a century; it’s been the subject of in-depth studies in physics, physiology, and even robotics. While some of the details are still unclear, the essential picture is that cats (almost) always land on their feet thanks to an impressive spine-flexing twist maneuver which turns them upright in midair.

Head over to Beacon for the full story…

Speciation in Reverse

07 Monday Apr 2014

Posted by in Evolution

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I don’t usually advertise my Accumulating Glitches posts on here, but I decided to make an exception for today’s post. It’s about a relatively straightforward study that raises a host of interesting questions which I thought some of you might find interesting. Here’s an excerpt to give you an idea:

Darwin’s finches have become a textbook example in evolutionary biology, speciating as they adapted to different environments in their spread through the Galapagos islands. In the past two decades, the opposite has been happening on Floreana island in the south of the archipelago, according to a paper published in the journal American Naturalist. The opposite of speciation, however, isn’t necessarily extinction — at least, not in the familiar sense of a species dying out. Another way for speciation to roll backwards is through hybridization, a process that raises many more (and more interesting) questions than ‘straightforward’ extinction.

Click to continue reading on Accumulating Giltches…

Ref
Kleindorfer S, O’Connor JA, Dudaniec RY, Myers SA, Robertson J, & Sulloway FJ (2014). Species collapse via hybridization in Darwin’s tree finches. The American naturalist, 183 (3), 325-41 PMID: 24561597