Introduction to Archery: Terminology, Definitions, and Specifications

I’ve posted reviews on here about both my Hoyt Charger and my Prime Rize. In those posts, I bounced around a little between straight up reflections on the equipment I use and background information on some of the terminology and specifications I was describing. Many people who were reading those posts probably wanted to skip right to the gear talk, while others could probably use a primer on the lingo, so I decided to separate the posts and create one that is just a backgrounder on the terminology you will encounter when beginning archery.

I shoot mainly compound bow. I have a longbow made by Rudder Bows, but I have to admit I don’t shoot it as much as I should. So this post mainly focuses on compound bow archery, with a slant towards bowhunting applications.

Parts of a Compound Bow 

Compound bows take the standard components of a bow and add some pieces of technology to make them more efficient at storing and releasing energy. Longbows and recurve bows have two or three main parts: a string, limbs, and a grip.


Parts of a longbow. Source: Michigan Hunter Ed Course

Compound bows have a riser (the vertical part you hold, with the grip), limbs (the pieces that attach to the riser and hold the cams), cams (the wheels at the top and bottom of the bow), a string (the part the arrow attaches to), and cables (the pieces that connect the cams to each other or to the limbs). The cams are what give compound bows the ability to shoot with much more power than the shooter actually holds – like any pulley system, they increase the efficiency of energy storage and reduce the amount of effort the user needs to put in. There are different styles of cams that all have their own advantages.

The axle-to-axle (ATA) length is the distance between the tips of the limbs, at the points where the cams attach. The brace height is the distance from the riser to the string when the bow is at rest. Bow speeds are measured in feet per second, and manufacturers use a standardized setup to compare speeds across different bows (IBO speed). The draw weight of a bow, in pounds, refers to the power a bow can transfer to an arrow and push it off the string. So a 40# (pound) bow will shoot with less power than a 70# bow. Hunting regulations will stipulate how much power a bow needs to have for particular species. For example, to hunt whitetails in Ontario, the bow needs to have about 40# of power, whereas to hunt moose, it needs 50#.

Compound bow measurements. Source: Hunter's Friend.

Compound bow measurements. Source: Hunter’s Friend.

Arrow Selection

(This section is an excerpt from a more thorough post about arrow selection.)

The first thing you need to know when selecting an arrow is what spine you need. Most choices in arrow selection come down to personal preference, but not spine. Arrow spine refers to the stiffness of an arrow, and it’s critical for the safety of your bow and for accuracy that you choose the correct arrow spine.

Imagine you drive a truck into the end of a horizontal telephone pole. Imagine  you drive the same truck into a tooth pick. Finally, imagine you drive it into a 2×4. While perhaps a little rough around the edges, this analogy is meant to explain what happens if you shoot an arrow that is too stiff or too weak for your bow. When the bowstring pushes the arrow off the end of the bow, the arrow flexes, stabilizing throughout the course of its flight. Simply put, if your bow is too weak, the arrow can`t flex enough; if your bow is too heavy, the arrow flexes too much. At worst, these situations could damage your bow, but they will certainly reduce the consistency and accuracy of your shooting. The rule is that heavier bows require stiffer arrows.

Every arrow manufacturer has a way of designating the spine of their arrows, and while the system used to measure spine stiffness is standardized, the systems used by manufacturers to represent spine is not. Easton’s system is generally the easiest to understand, because they use the direct measurement for “arrow deflection“, which is the way spine stiffness is calculated. With Easton arrows, the lower the number, the stiffer the arrow. 20151218_232210So a 70# bow might shoot a 340 spine arrow, while a 60# bow might shoot a 400 spine arrow. All arrow manufacturers will have charts (Easton, Carbon Express, Gold Tip) to help you identify the correct arrow spine based on your bow specifications (e.g. poundage, draw length, and arrow length). Be sure you understand how your specifications affect spine selection. Click here for a great resource to explain some of the finer points in arrow spine.

Is Speed Important?

Speed is one of the most hotly debated topics in archery and bowhunting, and it’s probably one that new bowhunters will encounter. I discussed the issue of speed more thoroughly in my post about arrow selection, but here are the basics: it’s an important component in the equation to calculate an arrow’s kinetic energy (KE), which is what ultimately kills animals (the other component is arrow mass). So it’s true that a faster bow will transfer more energy to an arrow and therefore increase KE; however, speed is absolutely not the most important part of choosing a bowhunting setup and ensuring your arrows are effective at killing.

No matter what, bows are shooting arrows at subsonic speeds, meaning that the sound of a bow shooting reaches an animal before the arrow every time. To put this in perspective, consider that a bow shooting an arrow at 280 fps is considered a great hunting setup. Now remember that sounds travels at 1,116 fps. In general, do I want a fast bow? Sure. Am I willing to sacrifice all the other factors that I consider when selecting a bow to get one that’s a bit faster? Not a chance.

How To Prioritize Considerations

When choosing a bow, people prioritize different things, and no one is right or wrong, so it becomes difficult to take someone’s word on why one particular bow is the best. You should choose a bow based on the optimal combination of factors for your preferences and priorities. You need to shoot a few and decide for yourself what is most important to you because there will always be trade-offs. Essentially, it comes down to what feels the best, and then identifying why it is that that bow feels best: is it the weight, the draw cycle, the balance, the release, the back wall? The combination of these and other factors will make a bow feel good for you, and the most important thing in choosing a bow is finding the right combination of specifications and features. You need to be sure of your equipment and your ability with it.

If you are interested in how my particular priorities led me to select a bow, check out my Prime Rize post.

A Comment on Endangered Species


This post was sparked by a recent piece written by Steven Rinella, who discussed the terminology and legalities of endangered species in the United States. While the U.S. and Canadian contexts have many similarities, I thought it might be interesting to offer some information on the ecological and legal meanings of the various species at risk classifications in Canada. I’ve also encountered more than one comment that a particular hunted species is endangered, so there is at least some degree of misunderstanding about how the species at risk system works both in Canada and internationally and what these classifications mean.

Above the 49th parallel, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) is responsible for assessing individual wildlife species and recommending species that should be protected under the Species at Risk Act (SARA). COSEWIC was established in 1977, as a national independent committee of experts, to identify, assess, and classify species at risk in Canada. In 2003, the Canadian government passed SARA to provide legal protections and determine recovery strategies for species at risk. COSEWIC now acts as an advisory board, submitting its assessments to Environment and Climate Change Canada for final decision about whether to list a species under SARA.

Under COSEWIC’s assessment process, there are seven status categories: not at risk (NAR), data deficient (DD), special concern (SC), threatened (T), endangered (E), extirpated (XT), and extinct (X).


Some quick definitions: extinct means that the species no longer exists anywhere. This differs from extirpated, which refers to a species that still exists but has disappeared from a part of its range (such as wild turkeys in Ontario in the 19th century).  Endangered means that a species is facing extirpation or extinction. Threatened refers to a species that is not yet endangered but is likely to become endangered if no action is taken. Special concern means that a species may become threatened or endangered due to a combination of threats. So it’s important to remember that just because there are concerns about a species, this doesn’t mean it is endangered.

Internationally, the IUCN, established in 1964, is an inventory of species classified along similar criteria. The IUCN system includes 9 categories: not evaluated and data deficient; least concern and near threatened; vulnerable, endangered, and critically endangered; extinct in the wild and extinct.


COSEWIC assessments consider a combination of criteria, including a species’ population and habitat status, trends, and threats. As an example of how an assessment would recommend a particular status, a species would be considered endangered if the number of mature individuals shows a decline of 70% of more over 3 generations (or 10 years, whichever is longer). This decline can be a result of observed reduction in actual numbers, deterioration of habitat quality, a reduction in extent of area occupied by the species, exploitation/over harvesting, or factors such as diseases and pollutants. Species may also be considered endangered when they have small ranges, drastic fluctuations in population, or fragmented populations. COSEWIC assessments specifically exclude consideration of the socioeconomic costs or benefits to listing a species.


Atlantic salmon. Photo: Tom Moffatt/Atlantic Salmon Federation

Part of the intent (and benefit) of having separate bodies responsible for assessing a species and its actual listing under species at risk legislation is to maintain a separation between the science (COSEWIC) and politics (SARA) of endangered species. In other words, science makes recommendations for a species’ status, but the decision to list a species is made by elected officials who are accountable to a voting public.

The problem with this system is also the separation of science and politics.

The multistep process between submission of a COSEWIC report to the Minister (of Environment and Climate Change Canada) and a final decision on whether or not to list a species under SARA includes a 90 day window during which the Minister publishes “Response Statements” indicating how he/she intends to respond to the COSEWIC assessment, followed by a review by the Governor in Council (GIC), who (on the advice of the Minister) will make a final decision to either list the species, not list the species, or send the assessment back to COSEWIC to request more information. The decision about whether to list a species is therefore a political decision that does take into account the socioeconomic costs of the decision. Only after a species is listed under SARA is it afforded legal protections. At this point, the species’ critical habitat must be identified and management plans and recovery strategies must be designed.

A note about how the Canadian system compares to the Endangered Species Act (ESA) in the United States. A 2013 study published in the journal Bioscience compared the Canadian and American systems and recommended that they could each benefit from adopting some of the strengths of the other. In particular, this study suggested that the American system could benefit from an overarching national scientific body responsible for all species assessments. On the other hand, the ESA has stricter timelines, and listing decisions in the U.S. are not permitted to consider socioeconomic costs.


Allegheny mountain dusky salamander. Photo: Phil Myers/Ontario Nature

I personally agree that socioeconomic factors should be kept out of decisions on whether to afford legal protections to species at risk. These decisions should also not be determined by the priorities of the political party of the day. Perhaps I am taking an overly narrow or romanticized position here, but if a species is in any way at risk of extirpation or extinction, we should be doing everything in our power to protect the species and its habitat.

In fact, there is some basis for my disdain of political involvement in species at risk legislation. Multiple studies have found that harvested species and northern species are less likely to be listed under SARA. For example, a 2007 report profiled 8 northern and marine species that were not listed despite COSEWIC recommendations. For instance, beginning in 1991, multiple COSEWIC assessments have recommended that polar bears be listed as special concern, but they were only listed under SARA in 2011. This particular species example is somewhat of a political storm that is not the topic of this post, but it does illustrate the complications that politics introduce into this issue (though I will say that part of the decision not to list a number of northern species is due to the need to consult with wildlife co-management organizations that protect Inuit rights to wildlife, an issue I strongly support).


Beluga whale. Photo: Greg Hume

Regardless of my personal opinion, the real meat and potatoes question is whether or not species at risk legislation works. Does it do what it is supposed to do – lead to recovery of endangered species and protection of habitat? In the U.S., there is a notable example of species at risk legislation working in the case of grizzly bears. On our side of the border, a 2014 study examined cases of species that have been assessed more than once by COSEWIC, indicating that at least some time had passed for recovery strategies to work. This study found that out of 369 species that fit this criteria, 47% of species initially classified as special concern deteriorated in status (later being classified as threatened or worse). Only 20 species out of 369 received a “not at risk assessment” after initially being assessed as one of the at risk categories (special concern, threatened, etc.). The number of species that deteriorated in status outnumbered those that recovered by approximately 2 to 1. In addition, there is a general gap in identifying species’ critical habitat, meaning that fully effective implementation of recovery plans is impossible.

So the problem is that our species at risk legislation is not working well enough. Might it be doing everything it can? Perhaps. Am I satisfied with the results when even 1 species shows a deterioration in status? No.

What all of this points to is the urgent need to protect habitat. We can do everything we want to try to protect individual species, but without healthy habitat, it won’t be enough. We also need to follow the precautionary principle in every case of a species at risk to ensure we minimize the chances we take with its future survival. We need to make habitat and species protection a management priority in Canada (and of course beyond). This means that species at risk legislation needs to be timely in developing recovery strategies and strict in their implementation. Further, COSEWIC assessments, and therefore SARA listings, only consider the Canadian range of a species, even though its full range and ecological role may extend across borders. I would argue that we need to be taking action at the scale of a species’ historic range and ecology, not merely on a national scale limited by political borders. This will take internationally coordinated effort, and it’s worth the work.

Having said all this, I should also note that I’m not demonizing the system. I’ve said it before, but I have an immense pride in the North American model of wildlife conservation. There have been tremendous successes in the record of species that have come precipitously close to extinction and been recovered. But pride should not preclude critical reflection and a drive to improve. We also need to be accurate in our conversations. The next time someone comments about how hunters kill endangered species, take the opportunity to explain that this is not true. Though there is room for improvement in their management, there is no hunting season for any endangered species. Remember also that many of the biggest successes in actions on endangered species have been thanks to hunter dollars and efforts.