Color changing plants need three things to survive and grow. The first is water which they absorb through their roots. The next necessity for a plant to survive is carbon dioxide which they absorb from the air much like we breathe in oxygen from the air. The third and final component is sunlight which plants use as a source of energy to convert the water and carbon dioxide into Glucose, a kind of sugar, which plants need to grow. Ultimately, the glucose is the food and the water, carbon dioxide and sunlight are the materials the plant needs to make that food.

As you may have guessed, it’s the leaves of a tree that turn sunlight into the needed energy to power their glucose manufacturing plant in a process known as photosynthesis. One of the chemicals that aids in the process of photosynthesis is chlorophyll. It’s also responsible for the green color common to leaves.

Now, as the days grow shorter and the nights grow longer, there’s a net loss of efficiency in a plant’s ability to photosynthesize. Basically, there’s just not enough light to effectively power the factory to make the glucose. Ultimately, the energy required to feed and maintain leaves that aren’t doing the tree much good in the winter is simply not worth the effort. The leaves are also vulnerable to freezing temperatures. Rather than work hard and expend energy to maintain low producing element, the tree is better off shedding its leaves and feeding on stored energy sources until the days grow longer again.

So what to do with all those leaves? Well, remember we mentioned that chlorophyll is responsible for photosynthesis and for giving a leaf its green color. And, in the spring and summer, there’s a lot of chlorophyll. But as autumn comes, one or two things happen.

The first thing that happens is that production of chlorophyll dwindles and eventually stops entirely. As the chlorophyll vanishes, it not longer overpowers another chemical (a pigment that was there all along) called carotenoid. Read that word carefully again and you can guess what that implies for the leaf.

Carotenoid is responsible for yellow and orange coloring in many familiar plants such as corn and carrots. Now, remember, it was there all along in the leaf but simply overpowered by the abundant chlorophyll. With the chlorophyll diminished or gone, those brilliant yellows and reds begin to show.

The second thing that may happen in some leafy plants is the production of another chemical (pigment) called Anthocyanins. Unlike carotenoids, anthocyanin wasn’t in the leaf the whole time (unless we’re talking about a year around red-leafed plant) but is generally produced in autumn. Anthocyanin is responsible for those brilliant reds you see on some trees in fall. You may be thinking, “yeah, but some trees skip red altogether.” You’re right! Not all trees can make anthocyanins.

The theory behind why some trees produce anthocyanins and do so with more vigor in some seasons than in others is that it is believed that anthocyanins are responsible for delivering late-produced sugar sap (glucose) from the changing leaves to the tree before the leaves fall. In a mild fall season with no early freeze, the tree takes advantage of every last minute of photosynthesis, but the cold nights make sap transfer from the leaves to the tree particularly difficult. It is believed that anthocyanins help to facilitate the transfer.

And now you know why some trees have leaves that change color and why they do so. Can you think of a tree that stays green all year? And why are you sitting here reading this, anyway? Shouldn’t you be out there enjoying a great fall adventure full of color?

Interestingly, the Kübler-Ross model potentially applies equally well to other traumatic or painful events. Looming eviction, the death of a beloved pet, the loss of a career make-or-break deal, a potentially significant prison sentence, divorce, loss of friends, etc are all potential triggers for the application of the model.

The determining factor in the application of the Kübler-Ross model is not so much the event but the potential pain or importance the individual associates with the event. Given two people facing a lay off, one may cope perfectly fine with the job loss and see it as an opportunity to try new things and finally get out of a dead-end position. The other individual, having staked their future plans on a continued career with the same company they loved working for, might well find themselves going through the five stages of grief.

It is also important not to assume cause. Somebody passing through the five stages of grief after a divorce might not be missing the person they’ve divorced in the least. Divorcing an individual you’ve been desperate to get away from for years will likely not evoke the 5 stages of grief over the absence of that individual whom you are divorcing. Dealing with several years of wasted time, and the failure of a marriage you’d staked your future on, however, might.

Finally, not all individuals will pass through all five stages of grief, do so in any predetermined amount of time, or necessarily do so in the order outlined below. Kübler-Ross asserts, however, that any individual dealing with significant grief will certainly pass through at least two of the stages.

The 5 Stages of Grief proposed by Elisabeth Kübler-Ross are:

•  
  • Denial
  • Anger
  • Bargaining
  • Depression
  • Acceptance

As an example, a person going through the failure of their business might include -

Denial - “This can’t be happening. I did everything right. It must just be a brief downturn.”

Anger - “Why me! I worked so hard! If that competitor hadn’t opened across the street I’d be fine. Damn them!”

Bargaining - “There must be a way out of this. I’ll do anything!”

Depression - “What’s the point? Nothing works. I’m a failure. I just want to crawl under a rock and die.”

Acceptance - “I did do everything right. Sometimes things don’t work out the way you plan, I guess. Best if I sell off the remaining inventory, salvage what I can, learn from my mistakes and try again. It’s not a reflection on me. It just is what it is.”

The HowDoWhy staff has lost a beloved family member. We are currently in stage 4 of the model.

Bunny, you’ll live on in our hearts forever. Thank you for all the good you’ve inspired. We miss you terribly.

FeLV - often called Feleuk (fee-look) by veterinarians can be spread between cats via nasal or oral secretions. Sharing common food and water bowls is one method by which the virus often transfers between cats. Biting, nursing and sharing a litter box are other methods of transmission. A common description of the virus that is readily understood by laypeople is Feline AIDS, as the primary cause of fatality with FeLV is the same - compromised immunity.

There is no evidence to imply that Feline Leukemia is transferable to humans, dogs or other non-feline pets. In fact, overwhelming evidence implies the contrary as there has never been a case of FeLV detected in humans or dogs which are often exposed to infected cats.

Approximately 40% of infected cats manage to defeat the virus entirely. Others progress through multiple stages (in some cases defeating the virus). 30% of animals unable to defeat the virus experience a full progression which is usually fatal. The virus itself does not kill the cat; it compromises the animal’s immune system generally leading to fatality caused by any number of infections the weakened immune system is unable to stave off.

As of this writing there is no cure for feline leukemia though treatment aids are available. That said, your best course of action is one of prevention. Vaccinations against FeLV are readily available. Consult your vet to schedule vaccination and ensure he fully briefs you on potential complications arising from vaccination.

For more on cat and dog health and symptoms read our post How do I know if my dog or cat is sick

What is really surprising is that the largest creature on Earth feeds almost exclusively on krill. These tiny animals average 1 to 2 cm in length. What they lack in size they make up for in quantity. Blue Whales consume around 40 million krill a day!

Blue Whales can dive for 30 minutes or more, though they typically spend 10-20 minutes submerged when feeding. They can reach speeds up to 30mph but typically cruise at around 12mph. For more Blue Whale facts, visit the American Cetacean Society.

While originally an acronym for a specific piece of diving equipment, scuba is now a common word which can be applied to the act of diving with closed circuit equipment or any of the other diving gear a scuba diver may use. Today, one is a scuba diver or certified in scuba diving rather than a diver using SCUBA equipment.

If you are interested in becoming a certified scuba diver and experiencing the amazing underwater world around us, please visit Break Away Adventure to read their introductory article on the scuba diving.

Giant Hummingbirds have relatively dull plumage compared to many other varieties but still sports the characteristically long beak to access nectar in the trumpet-like blossoms of its favorite energy sources.

Giant Hummingbirds are native to the western South America and in the Andes, specifically, ranging from Ecuador to as far south as northwestern Argentina. For video of this amazing bird, visit the Internet Bird Collection (IBC).

Nectar - or the sugary water solutions we add to feeders for hummingbirds - is a rich source of energy but it completely lacks protein and other nutrients hummingbirds need to grow, breed and survive. But a hummingbird’s metabolism and energy requirements are so high that it requires the energy from nectar to survive as well. So where does it get protein, vitamins and nutrients? Insects and spiders, same as other small birds.

So when you think of what hummingbirds eat, think of it this way - hummingbirds eat nectar to power their ability to hunt and eat bugs!

To read more about hummingbirds, what they eat and how to attract and feed them visit the Hummingbird Feeding Guide.

Boiling water is simply approaching a transition state between one form and another. It is in a liquid state and approaching a gas state. In order for any material to change states you either have to increase or decrease energy. Basically, you’re trying to excite or calm the molecules in the material.

In the case of water, its normal “room temperature” state is as a liquid. Remove heat (energy) sufficiently and it will become a solid (ice). Increase heat (energy) sufficiently and it will become a gas (water vapor or steam).

Now, and here’s where my science breaks down a bit, if I want to boil water, I have to excite those molecules. I have to get them moving. A passing familiarity with the laws of motion had me thinking that it’s easier to move a boulder already in motion than it is to move a boulder that’s standing completely still. It takes less energy to move or maintain motion in something that is already in motion. Seems that would apply at the molecular level too, wouldn’t it?

If you accept that you need energy to “move” water molecules sufficiently to boil water and you also accept that the molecules in cold water are moving slower than the molecules in hot water, common sense would dictate this myth is false. The same amount of energy applied to the same amount of cold water vs. hot water should result in reaching the boiling point more slowly. It also stands to reason that a pot of water just short of boiling is going to get there a lot sooner than a pot of water pulled from the freezer just before it freezes.

So there’s the common sense approach of applying logic. The actual experiment was pretty simple. Let the faucet run on cold, fill a pot with two cups of cold water and time how long it takes to boil. Then repeat but use water from a hot tap. In an effort to inspire your own scientific interest, I’ll leave it to you to try out but I’ll give you one big hint on the results. The myth was wrong.

The Bee Hummingbird consumes nectar from flowers to fill its energy needs but, like all hummingbirds, also eats insects for nutrition, protein and vitamins not present in nectar.

Other interesting facts about the Bee Hummingbird - its wings beat at around 60-80 beats/ minute and as fast as 200 beats a minute when mating! Like other hummingbirds, Bee Hummingbirds are hearty eaters, consuming almost 8 times their mass in liquid every day (that’s not counting the insects they eat as well).

For additional information on attracting and feeding hummingbirds, visit the Hummingbird Feeding Guide. Remember, though, that hummingbirds are only found in the Americas.

Limping - Before calling the vet, check your pet’s feet and between the pads. I’ve removed my fair share of thorns from my own pets. If your pet has a good amount of fur between the pads and you’ve just returned from a winter walk, make sure balls of packed snow or ice haven’t formed in the fur between the pads. Also consider what your pet has walked through. One of my dogs once limped uncomfortably and I discovered she’d walked through a puddle of battery acid. A good rinsing with soap and water fixed her right up. If you can’t determine cause, contact your vet.

Frequent or repeated vomiting - I’ve never known a pooch who didn’t throw up now and again, but the key to look for is, does it happen several times over the course of more than one day or does it happen a lot in a single day? If your pet vomits multiple times in a day or a couple times a day for 2 or more days, a call to the vet might be in order. If your cat vomits up what looks like a mouse without bones or tail, it’s probably a hairball and nothing to be concerned about.

Listlessness or lethargy - Any animal easily enticed into playtime who suddenly shows a significant decline in energy and enthusiasm is a good candidate for a vet visit. This is particularly true if there are other symptoms.

Sudden hair loss - Loss of hair can be indicative of several conditions from relatively easy to cure parasitic causes to serious illness that requires more rigorous treatment. Take your pet to the vet if you begin to notice sudden hair loss that exceeds the normal shedding common with seasonal changes.

Foul odor from the ears - Dogs and cats can suffer from ear infections. Floppy-eared dogs are particularly prone. If you notice a foul odor from their ears, a visit to the vet for a good cleaning and treatment is suggested.

Stops using the litter box - A cat that has been a real champ about using a litter box who suddenly starts adopting bad habits may not, in fact, be acting out in angry kitty rebellion. Cats with urinary tract infections or crystals in their urine will begin to associate their litter box with painful urination and may begin to avoid it. Keep in mind, though, that there could be other motivators particularly in males who may just be spraying to mark their territory. The key indicator is the change from good habit to bad habit. If you are at all unsure, call your vet and get their opinion. Do remember to clean the box regularly, though. Cats will often abandon a messy litter box in disgust.

Won’t eat - It’s always a good idea to have your pet on a fixed feeding schedule. It’s probably the best way to manage weight. Of concern to this post, though, having your pet on a fixed feeding schedule will allow you to determine if she’s off her food. This is particularly important in multi-pet households where it’s difficult to tell who has been eating if you just leave full bowls of food around. If you pet skips two or three meals, give your vet a call. Sooner, if there are other symptoms such as vomiting.

Drinks excessively - If your pet has a seemingly unquenchable thirst with no reasonable cause (high heat, just returned from an active walk, etc) give your vet a call. Excessive thirst can be a symptom of many conditions.

Diarrhea - Like people, some dogs and cats have naturally sensitive stomachs. If you find a food that agrees with your pet, stick with it. Avoid feeding your pet table scraps. If your pet is on a consistent diet but suddenly begins to experience diarrhea that lasts more than a few days, give your vet a call.

Frequent Urination - Knowing your pet’s habits will help you recognize this symptom. If your pet starts to urinate frequently or tries to urinate substantially more often than usual but is unproductive, she might be suffering from any number of ailments. Like humans, animals can suffer from bladder and urinary tract infections, stones and crystals (common in cats). A noticeable change in urinary habits would definitely warrant a trip to the vet.

Worms - Often (but not always) visible in the stool, worms can appear as small rice capsules or thin noodles. See this and it’s definitely time for a trip to the vet. Your pets should be on a preventative and given routine check ups. This is particularly true if they are outdoor animals as they are more prone to contracting worms and other parasitic infestations.

Labored breathing - Uncharacteristic panting or apparent difficulty breathing can point to many conditions including some very serious issues. Call your vet immediately.

Bloody stool - A good rule of thumb is that visible red blood in the stool means bleeding in the lower Gastro-intestinal tract (think closer to the butt). Tearing or damage caused by sharp, undigested objects that have passed mostly through the GI tract can do minor or serious damage on the way out though less traumatic causes are also possible. If red blood is visible for more than a couple days, give your vet a call to rule out anything serious. Of significant concern is a black, tar-like stool that might possess a particularly “sharp” or acrid odor. Black tar stools are a sign of intestinal bleeding higher up in the digestive tract and can be a serious symptom. Immediately call your vet if you notice this.

Loss of coordination - A pet that staggers, can’t stand upright or whose eyes dart back and forth (much like you would if you were spun around repeatedly and stopped) could be suffering from severe neurological problems or inner ear disorders. Immediately take your pet to the vet.

Soreness or sensitivity to touch - Animals instinctively try to hide their pain. In the wild, showing weakness can mean being left behind or becoming prey. So if your dog yelps or your cat yowls in pain when touched, there’s definitely something wrong.

Dehydration - Usually a symptom of a larger condition such as frequent vomiting or diarrhea, dehydration is a very serious issue. You can easily determine cases of severe dehydration with a simple skin test. Like your own skin, an animal’s skin should be elastic. Pinch a loose area of skin on your arm and you’ll see it immediately springs back when released. To test your dog or cat, gently lift the skin at the scruff of its neck (the same place a mother might carry her offspring). In a healthy animal, the skin will spring right back when released. You should try this now when your pet is healthy so you know what it should look like. If your pet is severely dehydrated, the skin will slowly recede back to its original shape. Should this happen, immediately get your pet to the vet.

Paleness - Seems odd but, yes, you can check if your pet is pale. First an example - with one finger, press hard on the palm of the other hand. See how the area turns white? Now let go. See how color rushes back in to where you were pressing? The same test can be performed on a pet’s gums. Lift the animal’s upper lip and press a finger against a relatively wide area of gum around or behind the canine tooth. You should see exactly what you saw with your own hand… the area will whiten with pressure and rapidly turn pink when you let go. It should only take a second for color to flow back in. Anything approaching two or more seconds can be indicative of circulatory issues or anemia and would warrant a vet visit. Like the test for dehydration, try this out on your dog or cat now while he’s healthy so you can learn what looks normal as a reference. If your pet is already ill, just follow the rule that the process should take no more than about a second. A slow, 2 second refill of color should result in concern and action particularly if there are other symptoms of illness.

I could continue all day but this is just a list of suggestions, not a primer on veterinary medicine. Ultimately, your own informed judgment and familiarity with your dog or cat will be your best guides. If you know your pet well, you’ll often know something is wrong before others would even recognize any definable symptoms. Spend some time with your pup or kitty every day both to ensure your mutual happiness and to be alert to his or her needs.