The California Varmint Callers Association
DEDICATED TO THE SPORT OF VARMINT CALLING.

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Animal activity and moon phases.

A complete moon phase cycle is measured from one new moon to the next (a "new moon" means there is no moon visible at all ). Beginning from the new moon, each day we will see a little more of the moon until the full moon is seen. Each day from there we will see progressively less of the moon until reaching the next new moon. This period is known as a synodic month and is about 29.53 days in length. The lunar year is 354.36 days in length and is about 11 days shorter than the typical year. Since the lunar year can't be divided into the typical year evenly, we wind up with a difference in phase between the two. Each day the moon will rise and set a little later in time and accounts for why you will see a full moon in the middle of one day and a while later will see it in the middle of the night. If you were to see the full moon directly overhead on 31 December it would be about 33 years before you again see it directly overhead on that date with the same phase. 33 years between the same moon phase, position in the sky and calendar date makes for great difficulty in correlating an animals behavior to the available night-time light levels.

The moon rises and sets at various times throughout the year and it will remain in the night sky for more or less time depending on how high up in the sky it is. The higher overhead the moon is the longer it will remain visible at night.

Moon Phases

The lower towards the horizon the less time it will be visible. The moon's phase will change during all this and though it may be directly overhead it may just be a sliver or crescent and therefore not very bright. Determining the exact moon phase with the rise and set times for any given day and location on earth is a complicated mathematical process and beyond the scope of this writing. If you want to plan your hunt with consideration to the moon phases, there are a number of sources available that will calculate the moons ephemeris (position in the sky) and rise/set times for you.

Animal activity and moon phase are known to be related. The amount of light available from the moon will determine the level of activity of many animals. With a new moon , predatory animals have difficulty seeing at night and will be less successful in feeding. Experience has shown that predators will respond to calling a little better during days with a new moon. As the moon phase progresses and the available night-time light level increases you may find a corresponding decrease in the animals willingness to respond to your call. This is not a hard and fast rule as other factors will affect the animals willingness to respond to the call. Disregarding the moon phase for a moment, as a general rule you will find most predatory animals active from the early evening (around 1 or 2 hours before sunset) till about 11 or 12 at night when their activity starts to slow down. Their activity will begin increasing again around 3 or 4 in the morning while not slowing down again until around 10 or 11 in the morning. Again, there are no hard and fast rules in this regard as you can find animals more or less active at all times of the day or night. Regional, environmental factors play a big part in this.

In your area, numerous factors will affect the level of an animal's activity and the current moon phase is just one of those factors (none-the-less an important one). Animals will react in various ways to the conditions present in their environment and knowledge of these factors and their affects on an animals behavior can help you to determine the most productive times to hunt. If you have done any amount of hunting at all you may have asked yourself questions that every hunter sooner or later gets around to asking. "Why is it that one day I go hunting and I see all kinds of animals and then the next day can't find anything at all? There doesn't seem to be any rime or reason to it"! No one, I think, has the pat answer to this question - this writer included. But years of hard won experience by varmint hunters and others have allowed us to draw a number of generalized conclusions regarding animal activity.

Ask an experienced deer hunter if he will hunt after a night with a full moon. The answer could easily be no. The reason for this answer lies in the animals behavior and it's response to the surrounding environment. Nights with a full moon or nearly a full moon will allow deer to see at night. They may have been feeding all night and as result will be less active the next morning. Remember, these are general conclusions and exceptions can always be found. Almost all animals are preoccupied with gathering food and if they can feed at night often will. The amount of hunting or predatory pressure the animal experiences will affect it's behavior. In areas where animals experience little hunting or predatory pressure you will most likely find them feeding all day. The animal may have plenty of food available and have little to fear from its surroundings. As a result they can afford to behave in a leisurely manner. Baring a severe winter die off or deaths from disease the animal populations in these areas naturally expand until some environmental factor causes the population balance to be restored.

Environmental factors such as climatic conditions, available food supply and competition from other animals will effect their population and level of activity. Consider the caribou and its never ending trek across the frozen north as an example of an animals response to its environment. They are always moving, following the greening grasses for thousands of miles and then retreating as the weather closes in on them. As with most animals, their behavior is finely tuned to the ebb and flow of their environment. The caribou's predictable set of behaviors are due to the clearly defined, abrupt and severe seasonal changes it experiences. The caribou simply must behave the way it does or die. Its range being so far north subjects it to environmental extremes most other similar animals never experience. How many land based animals do you know of in North America that migrate thousands of miles every year in response to a changing environment? Game species with a more southern range don't need to have the predictable set of behaviors of the caribou in order to survive. The seasonal changes here, for the most part, are less severe.

Predatory animals are affected by the same ebb and flows of nature and in addition, their behavior and populations are closely tied to their prey. In the desert during midday it is simply too hot for any significant level of activity. Predators will bed down and wait out the heat. When hunting in the deserts you will, during certain times of the year, encounter windy conditions. Experience has shown that when the wind kicks up the animals bed down. Most experienced varmint hunters will pack it up and go home or wait out the wind. There are of course regional differences in animal behavior and those behavioral differences will be determined by the factors that affect the animals chances of survival. In short, the animals will adopt those behaviors necessary to ensure its survival. Even those animals with a developed sense of night vision have difficulty seeing on nights with a new moon. You can bet they will be more active the following morning. The morning after a few days or even weeks of heavy weather followed by a night with a new moon may be the most productive time of all. The bad weather has forced them to remain bedded down and the dark nights have denied them the ability to feed at night. The next available clear weather morning is the time you want to hunt. Sometimes you can pick up various clues that can help you in determining the likelihood of a successful hunt. I have been told by more than one experienced varmint caller that if you see the cows bedded down that your hunting will not be good. I am not sure of the reasons for this one but know it to be generally true as I have experienced this myself. Another clue is the level of owl activity the previous night. If you see a lot of owls active then your hunting will not be good. Granted, a lot of this may sound like the typical "old wives tale" but then many old wives tales have at least some basis in reality. I suspect the reason for a correlation between owl activity and hunting success may have to do with the fact that both owls and coyotes share a common food source of mice and other small rodents. If there are few coyotes in a particular area, the area may experience an increase in the rodent population. Naturally, the owl will increase its numbers in taking advantage of this food supply. Keep an eye out for kit fox. If you see a lot of kit fox in a particular area you will find few coyotes. Here again, experience has show a correlation between the numbers of kit fox and coyotes. I have seen kit fox and coyotes together in the same area but not very often. Even the predominance of certain plants can be an indicator to the numbers and varieties of animals you will find in a given location. Keep in mind that these are generalizations learned from years of varmint hunting and that you will occasionally find exceptions to these rules. How well you are aware of, or how well you are tuned into your environment will play a large part in the success of your hunts. In determining the best time to hunt in your area it will help to know the weather conditions, moon phases, available food supply, competition from other animals, hunting pressures, the time of year, water availability, etc.

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