Hot answers tagged

89

Short Answer Yes. handedness (or Behavioral Lateralization) has been documented in numerous vertebrates (mammals, reptiles and birds) as well as invertebrates. This includes domestic cats (see Wells & Millsopp 2009). Long Answer There have been numerous studies that have documented behavioral lateralization in many groups of animals including lower ...


80

The reason is simple: Chocolate contains cocoa which contains Theobromine. The darker the chocolate is (meaning the more cocoa it contains) the more theobromine it contains. This is a bitter alkaloid which is toxic to dogs (and also cats), but can be tolerated by humans. The reason for this is the much slower metabolization of theobromine in the animals (...


74

That is certainly an interesting question! First, to clarify definitions: To be considered venomous the toxic substance must be produced in specialized glands or tissue. Often these are associated with some delivery apparatus (fangs, stinger, etc.), but not necessarily. To be poisonous, the toxins must be produced in non-specialized tissues and are only ...


67

If you compare placental mammals in how much time they need to start walking, you'll see that deer are no exception. Humans are an exception. Hypothesis of Obstetrical Dilemma The hypothesis of Obstetrical Dilemma states that humans are born premature. We very much think this is because if we were to be born more developed (like other mammals), our big ...


61

Yes, larger animals do experience larger delays in movement. There have been studies of size difference vs sensorimotor delays in terrestrial mammals, https://www.ncbi.nlm.nih.gov/pubmed/30158304 That graph is for innate reflexes of a needle to the hind versus a kick-time. Perhaps no one dared to prick a blue whale. Elephant vs shrew, heartbeat of 30 vs ...


59

Unfortunately, you're the first I've seen on here actually to have a bed bug. See this picture from University of Kentucky for comparison: Here is one moving (more footage & info here): Below is a picture from Bed-Bugs-Handbook.com demonstrating the relative size and appearance of 6 different life (molt) stages: From Left to Right: Nymphs to adults ...


59

A good exemple should be the “harpoon” in cone snails (Conidae), which is created from a modified tooth inside their proboscis. (Cone snail with proboscis, from KQED.org) The harpoon is launched at prey at close distance, and is used to poison and stun prey, and later to pull them in. According to high-speed camera capture the harpoon is launched in just ...


58

Their fur colour is actually a pretty good camouflage


58

Those are isolated turtle bones: Specifically, they are part of the carapace, or upper shell. The projections would articulate with the backbone. The "toothlike" structure at the other end projects down toward the margin of the shell. Based on the size, and the fact that you are in Missouri, I'm guessing they are snapping turtle bones. Here's a photo of ...


51

Short answer Intermittent locomotion can increase the detection of prey by predators (e.g. rats), while it may lead to reduced attack rates in prey animals (e.g., rats and chipmunks). It may also increase physical endurance. Background Rather than moving continuously through the environment, many animals interrupt their locomotion with frequent brief ...


44

This actually looks like a Gaudy Sphinx caterpillar (Eumorpha labruscae). It only mimics the appearance of a snake! You can find more information about this species here. Range: Argentina north through Central America, Mexico, and the West Indies to Florida, Mississippi, South Texas, and Arizona. Strays to Missouri, southern Michigan, Pennsylvania, Maine, ...


44

Adult butterflies don't eat! I mean.... not in the sense of chewing on food. They rather drink. They get their nutrients via ingestion of liquid substances. Their mouth consists of a long tube called a proboscis that acts as a straw. What do butterflies feed on? The vast majority of butterflies eat nectar from flowers. Many species are quite specialized ...


40

According to Cornell's All About Birds website, you will have to wait about a month for the nest to be cleared. The egg incubation period is 12–14 days. Following hatching, the nestlings will remain in the nest for another 13 days (i.e., the "nestling period" is 13 days). However, there are two caveats to this: A typical robin clutch size (i.e. the # of ...


38

They have mental maps of landmarks, which they use as well as "compass" cues: ... experienced birds can accurately complete their memorized routes by using landmarks alone. Nevertheless, we also find that route following is often consistently offset in the expected compass direction, faithfully reproducing the shape of the track, but in parallel. --...


38

Note: This is an answer to the last line of your question. A classical example of animals adapting to the influence of humans on their environment is the adaption of the Peppered Moth. Here is a brief summary: The peppered moth was originally a mostly unpigmented animal (<1800). During the industrial revolution in the southern parts of the UK a lot of ...


37

Short answer It is a flying lemur (there exist only 2 species). Flying lemurs and primates are together a sister clade to treeshrews. Easy source of information Have a look at the post The best free and most up to date phylogenetic tree on the internet?. In short, you can have a look at onezoom.org, tolweb.org or opentreeoflife.org by yourself! Tree of ...


36

You have a Dosima: Also known as a Buoy Barnacle. A gallery of observations of these can be found here: https://inaturalist.ca/taxa/462188-Dosima/browse_photos They are found in the coastal UK and Spain area, New Zealand, and east and west N.America: (source: iNaturalist observations) These barnacles attach themselves to things that float, and if they don't ...


34

Deer are hardly unique in this, The young of horses, cows, and I suspect most grazing species are able to walk soon after birth. The reason, of course, is evolutionary: flight is the species mechanism for avoiding predators, so if they weren't able to flee, they would become lunch for some predator. Other species have gone down an evolutionary route of ...


32

The anus of Octopus is channeled into its siphon. Image taken from Carina M. Gsottbauer Note: Siphon is a tube that leads from the mantle to the outside. Octopuses use their siphon to force water out in jets for propulsion and to flush waste products from the anus. From Encyclopedia of the Aquatic World, Volume 6 By Marshall Cavendish Corporation


30

Short answer It is believed that low water levels occurring several times during the last ten million years facilitated migration and divergent evolution of the felids. The North-American ocelot, lynx, puma, leopard cat, and domestic cat are believed to have evolved from a common ancestor that crossed the Bering land bridge between 5 to 9 million years ago ...


29

Based on the size and location that appears to be a Common mudpuppy (Necturus maculosus). (Photo © Brian Gratwicke — CC BY) The four toes visible on the front foot are also consistent with this identification. This species is found throughout eastern North America and you can learn more about them from the Canadian herpetological society and iNaturalist.


29

I think one of the important things to understand in thinking about this case is that it just hasn't been that long, generationally. Escobar imported the hippos in the late 1980s. Hippos reach sexual maturity at an average of about 7.5 years old for males and 9.5 years for females, space births about 2 years apart, and live for 40-50 years. Thirty years out,...


28

The two key concepts here are: sex-specific selection, and the fact that males and females share the majority of genes 1) sex-specific selection Obviously, any population where females lacked nipples would be in trouble. Men, on the other hand, have no evolutionary need for them, but they don't pay much either - there is no strong selection against men ...


28

This looks a lot like a double-barred finch (Taeniopygia bichenovii). Your note about this being an "owl-like" bird is supported by it's less common name, the "owl finch", so named for the dark ring around the face. Source: Wikipedia; Credit: Glen Fergus If this is in fact the bird you saw, you're right that it's not native to your country (or continent ...


26

This is a species in the Peristediidae family, commonly called armored searobins or armored gurnards. found in deep waters around the world, with most species in tropical regions. They are related to the searobins in the family Triglidae, and some authorities classify them in that family,2[3] but they are encased in heavy scales with prominent spines. ...


26

It's definitely a bird pelvis (synsacrum). Based on the size (~30 cm), it came from a very large bird. Unfortunately, comparative images of bird pelves are rare on the internet. Some possibilities (large birds of Sweden possibly found on the coast): Great northern loon Golden eagle Common crane A loon skeleton (from http://paolov.wordpress.com/2011/08/05/...


26

Skin First, you are being misled by your wrong assumption that hippos have soft skin. Hippos have a 5 cm thick skin! For fun, here is a picture of a hippo skin. They are big and pretty fast An adult hippo weighs on average 1.5 and 1.3 tons for males and females respectively (with a record at 4.5 tons) and can run up to 30 km/h on land and up to 8 km/h in ...


26

I'm almost certain that your question is based on the press that Patricia J Yang's research is receiving (e.g., here and here). Yang and her co-authors examined the structure and mechanics of some dead wombats to investigate this question further. They found that varying degrees of pressure in the latter portion of the wombat's intestines (in conjunction ...


25

The toxic ingredient in chocolate is in the mythylxanine class, a substance called theobromine. It is much like theophylline; overdoses of theophylline used to be very common before the advent of inhalers for the treatment of asthma. (Chocolate also has some caffeine in it, which may exacerbate the effects of theobromine.) As @Chris stated, it is only slowly ...


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