Have I Got One For YOU

“Beneful, please!”

The marketing geniuses at Nestle will air an ad targeted directly at dogs this week in Austria, featuring a high-pitched tone designed to appeal to canines, Reuters reports. The ad features the squeaking sounds of common dog toys as well as a high-frequency tone that is “barely audible to humans,” according to the news release. Noticeably absent from the release is the fact that all TV speakers are designed by humans for humans, with maximum frequencies reaching 20,000 hertz, the upper limit of human hearing. But most speakers top out well below this. While dogs can hear sounds up to at least 40 kHz, it’s almost impossible human speakers could broadcast any special tone that would be able to alert your dog any more than, say, a six-year-old.

But, giving “credit” where it’s due, the ad is clever, in a cynical-marketing-ploy way. “The television commercial aims to reach both the pet and the owner, supporting the special one-to-one relationship between them,” said Xavier Pérez, brand manager of Beneful for Nestlé Purina PetCare Europe. That special one-to-one relationship where Spot wags twice when he wants Beneful.

Image courtesy of Nestle

Anger not your fish.

Your fish are probably pissed off if you keep them in a small aquarium, suggests a study published this month in the Journal of Applied Animal Welfare Science that looked at levels of aggression in the common aquarium species Midas cichlid (Amphilophus citrinellus). Fish stored in average-sized aquariums used by most small collectors (i.e. tanks holding fewer than 100 gallons) were significantly more aggressive and violent than fish in artificial stream environments or home in their natural habitat. With 180 million or so ornamental fish in America, that’s a lot of mad fish.

Though the results may sound like common sense—no animal likes being housed in cramped conditions—this is one of the first studies to concretely measure aggressive bouts, attacks, and other behaviors indicative of the creatures’ state of mind in aquariums of varying size and complexity. These bouts ranged from fin-flaring to nips and full-fledged bites. Similar studies have found that cramped sea urchins result to cannibalism, and that great white sharks, which are very difficult to maintain in captivity for long, tend to lash out at other sharks (especially the unfortunately named “soupfin”) when confined.

While the news may give fish owners reason to think twice before plunking their bettas into mason jars, it’s not exactly practical to line your walls with aquariums or design a 1,200-gallon reef tank like this enthusiast. Luckily the picture isn’t totally grim: researchers found that when they introduced plants or complex environments like caves into aquariums, the fish became less aggressive. By making their environment slightly more complex, you can give them greater options for exploring and “hanging out.” Consider buying a larger tank or introducing more flair into your aquarium, and the “resulting natural behavior performed by the animals may make them more visible and engaging,” as one researcher observed.

Reference: Ronald G. Oldfield. Aggression and Welfare in a Common Aquarium Fish, the Midas Cichlid. Journal of Applied Animal Welfare Science, 2011; 14 (4): 340 DOI: 10.1080/10888705.2011.600664

Image: OakleyOriginals / Flickr 

“You poop on the boat, you eat the garden, and I’ll wreck the wall.”

Florida has long had a big problem with introduced exotic species like the Burmese python, which can grow up to 23 feet long and has wreaked havoc on native wildlife. But in many ways lizards are even worse, accounting for 77 percent of the non-native reptile and amphibians species that have set up breeding populations in the state, according to a study published this month in the journal Zootaxa. Green and Mexican spiny-tailed iguanas are a particular nuisance. Besides competing with the 13 local varieties of lizard, they are famous for voraciously eating gardens, damaging boats and other property with their corrosive droppings, and even destroying concrete walls by burrowing beneath them.

The study found that people have introduced 137 foreign species of amphibians and reptiles into the state over the last 137 years, at an average of one per year. That gives Florida the dubious distinction of having the greatest number of established exotic amphibians or reptiles (“herpetofauna“) in the world.

The number of unwanted critters grew slowly but steadily (like a certain fabled herpetofauna) prior to 1940 due to accidental introductions via cargo ships, mostly from Cuba. But the numbers began to increase dramatically in the 1970s and ’80s as the pet trade in exotic terrarium animals took off. Today this poorly regulated industry is responsible for 84 percent of the introduced species, researchers say. And despite the fact that introduction of a non-native species is illegal without a permit, nobody has ever been prosecuted for establishing a non-indigenous animal in the state.

None of this makes zoologist Fred Kraus too happy, who writes:

I suggest that the distinctive co-evolved, unique beauty of each of these systems is besmirched by the introduction of alien species – much as a beautiful beach or coastline may be impaired by an oil spill. Or perhaps more aptly, the facile pollution of these self-generated biotas by human introductions is equivalent to splattering the canvases in the Louvre with day-glo paint… the aesthetic integrity of the artworks is thoroughly violated. The difference, of course, is that the impact of an oil spill lasts for mere years, vandalization of a painting may be rectified by careful restoration, but alien invasions are most usually irreversible and irreparable.

Although he wasn’t specifically referring the Florida situation, he may well have been.

Image Courtesy of University of Florida IFAS Extension

Reference: Kenneth L. Krysko et al. Verified non-indigenous amphibians and reptiles in Florida from 1863 through 2010: Outlining the invasion process and identifying invasion pathways and stages. Zootaxa, 2011; 3028: 1-64. Link.

Got (pigeon) milk?

Pigeons are known all-too-well by city-dwellers the world over. But what you might not know is that these birds produce a substance similar to milk for nourishing their young, and researchers have begun to understand how the critters do it. The pigeon version of “milk” is produced in fluid-filled cells within their crop, a specialized part of the esophagus typically used for storing food prior to digestion. Both male and female pigeons begin producing it about two days before their eggs hatch, and dutifully regurgitate the cottage cheese-like substance into their baby’s mouths for several weeks, after which they gradually introduce softened food to ready their young squabs for the real world.

A study published today in the journal BMC Genomics looks more closely at how pigeon milk is actually made. The researchers compared levels of gene expression between “lactating” and non-milk-producing cells, finding a high level of activation in genes involved with antioxidant synthesis and cell growth. This helps explain why their “milk” has high levels of antioxidants like carotenoids and is rich in fat, containing three times as much as cow’s milk. Wild-raised pigeon squabs die without it, and one study found that chickens raised on it grew 38 percent faster than chicks on a typical diet.

Pigeons aren’t the only birds that can perform this mammal-like feat: flamingos and male emperor penguins also produce a milk-like substance to feed their young. These adaptations appear to have evolved independently from one another, offering researchers enticing clues about the composition of various animal’s milk and the function of lactation, which is all-important for mammals.

Let’s just hope no enterprising beauty-product company latches onto this news and turns pigeon milk into the next hot skin treatment.

Borneo’s Camponotus cylindricus ants are a little touchy: if they encounter a foreign ant in their territory, they will latch onto its legs with their jaws and then quite literally blow themselves up, spraying a sticky yellow substance over the unlucky intruder. Not exactly the most level-headed reaction, but an effective one for defending the ant’s territory. A recent study in the journal Acta Zoologica describes how these volatile buggers release their noxious lather: by squeezing themselves to death with their abdominal muscles.

When it comes to “yellow goo”—the researcher’s actual technical term for the post-squish spritz—these ants are literally full of it. The reservoirs that house the liquid make up as much as half the volume of the ant’s body and stretch from the base of the head to the tip of the insect’s abdomen. The goo is made  up of various irritating chemicals and strong adhesives that permanently bind the body of the dead Camponotus to the attacker. This enemy ant becomes subdued by the noxious chemicals, as well as the fact that it’s, well, forever glued to a corpse. After locking an enemy in a death grip, these ants bend and compress their abdomens so forcefully that the liquid violently ruptures out of several points on their rear-end. They aim for enemy’s faces, maximizing the power of the irritants and ensuring an immobilizing “attachment.” In your face!

Although it may sound a little extreme, this kamikaze tactic serves to protect the ant’s nest**************** and territory. Self-sacrifice is not uncommon in highly social animals, such as termites and honeybees that will fight to the death to protect the queen. Similarly, soldiers from one termite species will emit a glue-like material to trap anything attacking its colony, sometimes dying from the stress of the excretion. But Borneo’s exploding ants will even self-detonate far from their colony, or when lightly touched with forceps in the lab. Some studies have shown that the ants will leave certain smaller-bodied “enemies” alone, saving their suicidal spurts of putridity for larger ants. The strategy—trading a life for a life—seems designed to win a war of attrition against larger-bodied ants that may have lower populations.

So how did this rather unorthodox technique evolve? Some closely related ants have similar reservoirs that can house symbiotic microbes which help to digest plant matter [PDF]. Researchers speculate that some of the chemicals in the exploding ant’s yellow goo initially helped them break down the microbes and microbial by-products they feed on. Some of these compounds, such as irritants more commonly found in fungi, may have then proved useful in deterring enemies and led to the exploding adaptation.