How to do a bird count or survey

Let’s get counting! 

With the Aussie Bird Count just around the corner, we thought it was time to brush up on survey techniques and introduce newcomers to the joy of counting birds. And after the Count? That’s where Birdata comes in.

Bird surveys are the foundation of bird conservation—without the data they provide, we would struggle to determine (and justify) which birds need our help, and what the impact of our efforts is. Bird survey data helps researchers, land-managers, citizen scientists and volunteers keep track of bird diversity, assess habitat health, monitor environmental change and inform conservation. But while counting birds sounds simple enough (and often is), there are situations that might leave you wondering how exactly do you count birds? 

Bird surveys come in many shapes and sizes, including casual backyard counts, standardised surveys over specific areas, and even aerial waterbird surveys carried out by plane. All counts have value, but standardised surveys—where the area, time and method are consistent between surveys—produce the highest-quality data to guide and inform conservation. Standardisation of survey methods is used to make counts as comparable as possible across time and space, even when observers differ. 

Birdata—BirdLife Australia’s flagship citizen‑science platform—is the hub where these field observations inform the scientific insights required for our vital conservation work. Launched in 2005 (as the evolution of BirdLife Australia’s Atlas of Australian Birds project), Birdata now houses more than 30 million records. Submitted via a user‑friendly app or web portal, this data shapes everything from Action Plans for Australia’s birds to local threatened‑species advocacy.  

The gold standard: 2-hectare, 20-minute search 

This survey method gained prominence in Australia in the 1990s and is exactly what it sounds like: it involves searching for all birds that can be identified within a 2-hectare area for 20 minutes. The area can be any shape—a circle, rectangle or square—as long as the total area remains 2 hectares.  

Before the 1990s, bird surveys in Australia used different methods, and many were laborious and involved mapping. The 20-minute, 2-hectare method was developed by Richard Loyn (originally as a 20-minute, 3-hectare approach) for estimating the relative abundance of forest birds. “The method combines the simplicity of a simple transect with the flexibility of an area search,” he wrote in a 1986 paper. The method was adopted as a core survey protocol for BirdLife Australia’s ‘New Atlas’ project, which involved thousands of skilled volunteers across the breadth of Australia. 

“It is an efficient method,” says Richard. “I found that 20 minutes’ careful search could tell you a lot, and the method could be replicated easily and the results compared. And there was no need to mark an area, or carry out complex analysis.” 

Analysis of the data from 20-minute, 2-hectare surveys underpins various important conservation assessments, including BirdLife Australia’s past State of Australia’s Birds reports, Australia’s Threatened Bird Index, Key Biodiversity Area bird monitoring and a range of regional and local conservation initiatives. The survey method has also been adopted by the Australian Government’s Ecological Monitoring System Australia standards. 

“It’s the sweet spot” says Sean Dooley. “Where effort output and quality of results cross over. Look for any longer or further, and it’s a case of diminishing returns for effort.” 

So how do you do it? First, decide the area you are going to search. Ideally, your area will represent one habitat type only. Two hectares is a rectangle of 200m x 100m, or 400m x 50m, a square of 141 metres wide, or a circle with a radius of 80 metres. Estimating these distances can take practice, but Google maps and similar phone apps available now make it much easier. Set your timer, and start walking slowly through the area, watching and listening for birds. 

John Peter, who recently logged his 8,000th Birdata survey, suggests starting with a rectangle. “The easiest way is to walk for 200 metres and look for birds present within 50 metres on either side. An 80-metre radius can be hard to keep track of.”  

And how can you tell if a bird call you hear is within your search area, or outside? The consensus among those who do surveys often is “you can just tell”. 

“It’s an inexact science, but you can usually tell if a bird is calling from more than 50 metres away. It’s a fair distance away to hear something, and it usually sounds a long way off,” says John Peter. 

What about double-counting? Moving in one direction, and not backtracking, will help you avoid double-counting. Taking note when birds are on the move, and in which direction, will also help to avoid counting any bird twice.  

A flexible approach: 500-metre area search 

For some areas, like open savannahs, wetlands or swamps, a larger area search may be the best type of survey method to use. This protocol involves counting birds in an area within 500 metres of a central point (i.e. a circle with a 500-metre radius). This is a semi-standardised search, with the main constraint being maximum area, rather than time. 

With a 500-metre area search, the aim is to count birds in an area up to 500 metres from a central point—you are not expected to survey the whole area, which would be nearly 80 hectares and may take a very long time, depending on the habitat!  

This method is commonly used for wetlands and areas where the terrain is more open. This often means encountering flocks of birds which can pose a particular challenge. Accurately counting each individual in a flock may be impossible, but there are well-practised estimation techniques you can use.  It is always better to provide a reasonable estimate of the number of individual birds seen, than just to record that an unknown number were present. 

One of these estimation techniques is grid or block sampling, which can be used when a large flock is spread over a broad area. Mentally divide the flock into equal-sized blocks and count the birds in one of these. Then multiply by the number of blocks in the whole flock. You can also count a smaller number of birds—say 10 or 20—and get a feel for how much of the flock they take up.  You can then extrapolate by this number through the rest of the flock, essentially counting by 10s or 20s. 

Another technique involves taking a photo or video and counting later by zooming in and counting each bird. This is especially helpful when the flock is stationary (as when roosting). 

To prevent double‑counting, always let flocks settle before starting your count, record movement direction, and if surveying consecutive points or transects, ensure records indicate if the same flock may have been counted already. If the trail you are taking is a one-way trail and you are doubling back, either stop your survey half-way (before you turn around), or make it a rule that you’ll only include birds of different species, or additional numbers of birds of the same species that are greater than you saw on your outward trip. 

Incidental searches 

What if you spot a rare, interesting or uncommon bird, but you’re not actively surveying at the time? Birdata can accommodate this kind of sighting too, in what is called an Incidental search. Through the app, you can quickly log your location and sighting, making sure that this information isn’t lost. You never know how important a sighting might be! While we have a lot of information about birds’ ranges, with climate change, habitat loss and other environmental changes, birds are on the move, and we need to keep track of these changes. 

Aussie Bird Count 

One survey type won’t appear on the Birdata app—the Aussie Bird Count. This survey is designed to be easy and flexible, and is completed through the Aussie Bird Count app. Like the 20-minute, 2-hectare survey, it involves counting birds for 20 minutes, but rather than moving through a 2-hectare area, the counter stays in one spot, logging all birds they can hear or see from that point. 

The simplified protocol makes it easy for anyone to take part, and the Aussie Bird Count app has additional features that help to identify birds based on size, colour and key features. It will also let you know when a bird you have logged is well outside its usual range—a prompt for newbies to double-check that identification. 

The value of this point-in-time data is the snapshot it presents of the birds that live where we live. With over a decade of consecutive counts, we continue to build an archive of this annual snapshot over time. And for many, it’s the beginning of a beautiful journey watching—and counting—birds that leads to a deeper engagement with conservation and long-term monitoring.   

Your count counts—because it goes into Birdata 

So if you’ve enjoyed the Aussie Bird Count in previous years, and feel ready to spread your survey wings, why not get started on Birdata? Every careful count, every shrewd estimate, every heard‑only detection logged in Birdata adds to a conservation tapestry covering decades and the breadth of our continent. Whether you’re tallying kookaburras in your garden or tracking flocks of waterbird at remote wetlands, your observations power decisions—from local fire planning to national species recovery actions. 

With Birdata’s standardised survey methods, intuitive tools and massive scientific impact, your counting becomes part of something bigger—feeding national datasets like the Threatened Species Index or Action Plan for Australia’s Birds. So grab your binoculars and phone—or grab a cuppa in your backyard—and let’s count for Australia’s birds!