I undertake this topic with some trepidation. We discussed quail population management two blog posts ago and I hope I gave everyone a basic understanding of the dynamics involved within different levels of quail populations.
Of course, it’s hard to know how to manage a quail population without some knowledge of just how many coveys you have, or to carry it even further – what your quail density in birds per acre is. This discussion can quickly devolve into one that’s like trying to talk about tree density versus trees per acre versus basal area with a forester – none of it means anything to a landowner unless they can visualize what is being said. I struggle with how to best convey a practical method of quail population estimation suitable for the average landowner.
Several levels of population estimation need to be addressed:
1) you simply want to know if you have quail at all
2) you don’t plan to hunt your quail, but you would like to know if the habitat work you are doing is leading to a trend of increasing quail numbers and quail use of your land
3) you own a relatively small property (250 acres or less) and you would like to hunt it occasionally
4) you own a larger property and want to have an idea how many coveys you have and how many quail you should harvest annually
5) you manage a large quail plantation and it is critical to have a pre-hunt fall density estimate for your population.
We could come up with many more variations of these scenarios, but these will address most of your needs.
Case 1 – You simply want to know if you have quail:
For the complete bobwhite quail novice, you first have to become familiar with their songs and calls. Go to the Cornell University Ornithology Lab’s website at the link here http://www.allaboutbirds.org/guide/northern_bobwhite/sounds . Familiarize yourself with each of their calls. They’ll come in handy regardless of how intensely you want to get into population estimation. In case 1, you can determine if you have quail by listening for singing male bobwhites during June. They call well between sunrise and about 9:00 a.m. typically. Listening on days with nice, clear, still mornings is best.
Case 2 – Is your quail population trending in the right direction?
First, face some cold hard facts. If you own a small piece of land, perhaps less than 50 acres, maybe even 100 acres, there are only so many quail coveys you can pack into that area. It can vary based on what type of landscape your property exists in, but by-and-large once you reach a covey per 25 to 50 acres, you’ve done about as good as you are going to do. So if you started off with no quail, and you now have 2 coveys on 50 acres, you’ve done well. Your goal now is to manage and maintain the coveys you’ve developed.
The “June Call Count” is one way state wildlife agencies keep track of quail population trends over large areas (such as entire states). A “trend” gives no true estimate of quail density (coveys per unit of area, or quail per acre, etc.). A trend is an indicator of whether a population is increasing, decreasing or stable. For example, you purchase 1,000 acres of land and want to manage it for quail and other early-succession species. You’d like to track the population trend through time. This is relatively easy to do by setting up a June whistling male bobwhite call count. Get a good aerial photo of your property and set up listening points periodically in easily accessible areas. Try to keep the points at least 600 yards apart to avoid double counting (generally during summer a bobwhite song can be heard up to 250 – 300 yards).
Begin your count at sunrise on a good, still, clear morning. Listen for 5 minutes at each stop. Record the number of different males heard making the “bob, bob, white” call at each stop. It is best to run the route several times each year and get an average of the number of bobwhite males heard at each stop. The first year serves as your baseline. It will take several years to establish a trend. Through time you will be able to tell if your population is increasing, decreasing or stable. Do not let one “bad” year throw you. Anomalies occur in nature. Plot your numbers through time and focus on the overall trend.
Case 3 – The owner of a small property who would like to hunt it occasionally:
Some consider “small” properties for quail those being less than 2,000 acres. That is not practical for many. I use 250 acres as my criteria. On properties of this size, and maybe even up to 500 acres, I believe landowner “familiarity” is a relatively reliable way to track the number of quail coveys each year. By this I assume you are a landowner who spends a great deal of time on your land. You manage it, you know the cover, you develop a feel for what quail need and where they are and during any given year you have a good feel for productivity.
Was it a good hatching year? Did you receive good rainfall during June, July and August? Or did you suffer extreme drought? Did you experience any heavy flooding events during peak times when young broods would abound (late June, July and into August)?
By early fall, you probably have an idea about how many coveys are on your property and perhaps even have a feel for the size of those coveys. The one thing you have to use care to avoid is double counting coveys. Coveys do move around, so when you see coveys on different days in different locations that are relatively close to one another, you can’t be sure they are not the same covey. In your case, though, as long as you do not want to hunt frequently you can safely take some quail off your land during all but the worst years.
Estimate the number of coveys and use an average size for each, generally 12 to 15 birds, calculate the total and use 20% as a general guide on the number that can be safely harvested during all but the worst years. And by “worst years” I mean those summers during which you believe reproduction was slim to none.
Recent research suggests that harvest of adult bobwhites during seasons following years of poor productivity could slow population recovery (Miller et al. 2012). If you want to get any more precise than this, you might consider using the fall covey count method I will describe for Cases 4 and 5.
Cases 4 and 5 – Larger properties that will be hunted moderately or frequently:
I lumped these two categories because they involve either large properties where intense familiarity with the entire property is unlikely, or larger properties which will be hunted moderately to frequently.
For my purposes I consider 1,000 – 3,000 acre properties as “large” relative to most others in the mid-South. But the fall covey count method I refer to can be applied to larger properties up to 15,000 or 20,000 acres if resources and time are available.
The fall covey count method was tested and perfected by researchers at Tall Timbers Research Station in Florida (Wellendorf et al. 2004). I will not try to describe it in detail here. But it basically involves assessing your property, developing a series of listening stations designed to cover as much of the property as possible without too much overlap, and then using them to listen for morning covey calls in early fall (mid to late October usually).
As with many surveys, it is best to run the survey at least 2 times and preferably more if resources allow it. In my opinion, the fall covey call count is the most reliable way to accurately assess fall pre-hunt quail populations on larger land holdings. If properly applied, it can allow a property owner to practice “adaptive harvest management,” meaning that harvest rates can be modified annually based on pre-hunt fall population levels. It is applied extensively on some of the premier quail plantations in the Deep South, and has been used to assess the effects of large scale government habitat cost-share programs across multiple states. The method is described in great detail on the Tall Timbers website at http://www.talltimbers.org/gb-fall_densities.html .
I’ll wrap up by saying the more you know about the quail population on your land, the better you’ll be able to manage habitat and harvest. I hope this has at least provided you a place to start.
Citations:
Miller, R.S., W.E. Palmer and S.D. Wellendorf. 2012. Age-specific nesting performance by northern bobwhites. Proceedings of the National Quail Symposium 7:229-233.
Wellendorf, S.D., W.E. Palmer, and P.T. Bromley. 2004. Estimating calling rates of northern bobwhite coveys and measuring abundance. Journal of Wildlife Management 69:672-682.
