Beware of Praying Mantises

Beware of Praying Mantises
There are organizations that advocate natural control of pests as opposed to the use of chemicals. One effort to control garden pests involves the use of praying mantises. While the concept is good, there are complications. In the natural world with no human intervention, there is a balance between predator and prey. When humans upset that balance, the result is always catastrophic.

In Australia, for example, rabbits were introduced to control certain plants. The rabbits had no natural enemies, and in a very short time, the rabbit population was out of control. Now there is the problem of how to get rid of the rabbits. Here in Michigan, beavers have been brought back into the river where I live. Today they have no enemies, and the beaver population has grown to the point where it is almost impossible to keep decorative trees because the beavers eat them.

The December/January issue of National Wildlife magazine (page 10) brought a new issue to our attention. People have introduced large numbers of praying mantises to control the bugs that were eating their gardens. The problem is that they not only eat bugs, but they will also kill and eat hummingbirds. Some people who have deliberately added numbers of mantises to their property have discovered that they no longer have hummingbirds, and apparently the mantises are the cause.

The Wilson Journal of Ornithology reported a study in which there were 147 cases of praying mantises catching 24 different bird species. The praying mantises capture the hummingbirds at feeders or as the birds are getting nectar from a flower. When we see bad environmental situations in nature, it is almost always due to human mismanagement and not a fault in the design of the system.
–John N. Clayton

Hummingbird Tongues

Hummingbird Tongues
Outside of my window in the summertime, I have a hummingbird feeder. It is a real distraction because I am just a few feet from birds that flap their wings up to 90 times a second and have a heart rate of 1200 beats per minute. As I watch them stick their beaks into the feeder, I can sometimes see their tongues. I assumed that hummingbird tongues suck up the fluid using capillary action. My friend Richard Hoyt informed me that I was over-simplifying the process and gave me an article to expose my ignorance.

The article tells of the work of Alejandro Rico-Guevara. He realized that capillary action wouldn’t work in sugar solutions above 40%, but some of the liquids consumed by hummingbirds are twice that level of concentration. Rico-Guevara has photographed hummingbird tongues as they get the nectar. Instead of drawing in the liquid, the hummingbird has tubes down the side of the tongue. When it reaches the nectar, the tongue pulls back, and those tubes zip closed carrying the nectar back into the beak.

Ornithologists still don’t understand how swallowing can take place once the nectar is in the beak. Because hummingbird tongues are so efficient, there are many uses of this process in industry. Fluid traps are the newest thing in fluid dynamics, and the Creator already had this complex device built into one of nature’s most amazing creatures. My old idea that the tongue was a capillary tube was much too limited.

To read the article click here.
–John N. Clayton © 2018

Majesty in Miniature

Majesty In Miniature

“Majesty in Miniature” is the title of an interesting article in the July 2017 issue of National Geographic (pages 99-118). The article is about the amazing hummingbirds.

Scientists have had a hard time getting data as they try to understand how hummingbirds do what they do. The birds fly at speeds up to 35 mph (56 kph) and they have a “reverse gear.” Their metabolic rate is the highest of any vertebrate on the planet. For every minute they are in flight, they drink more than 12 ounces (355 ml) of water. They consume more than their body weight of nectar every day. Their tongues lap up to 15 times a second. Proportionally their brain is one of the largest in the animal kingdom making up 4.2% of their body weight. It is only with the advent of high-speed cameras and advanced wind tunnels that some of the mysteries of the majesty in miniature have been answered.

Hummingbird brains have a large hippocampus which allows them to remember locations. Their brain has a large lentiformis mesencephali motion sensor which gives the bird stabilization when flying. It has a small arm wing which allows wrist motion to control a larger area of the wing leading to a more powerful upstroke. When a hummingbird hovers, it rotates its wings between the upstrokes and the downstrokes making a figure eight motion. This motion creates vortexes that allow both the downstroke and the upstroke to provide lift. Birds such as pigeons push down to propel forward, but there is no lift in the upstroke. The design of the hummingbird wing gives it the unique ability to get lift out of both strokes.

The design of all of these features defies any chance explanation. Nearly everything the hummingbird does is unique to that species. We don’t see birds with some of these characteristics, and yet all of them are essential to the hummingbird’s survival. Indeed this bird is majesty in miniature, and a testimony to God’s wisdom and design. He has equipped all creatures to live in their particular, unique environment.
–John N. Clayton © 2017