A Day in the Life of the Nevada Bird Count

Bzzzzzzt.  My alarm goes off at the crack of why-am-I-awake.  Actually, it’s not so bad – my and Kelly’s surveys for the morning are within walking distance of last night’s camp, so no driving this morning, just the usual getting everything together – datasheets, binocs, rangefinders, GPS, extra pencil, waterbottles, and so on.  Usually, I bring my habitat assessment gear with me, too, but yesterday was an incredibly long day, and the afternoon’s agenda includes an unknown amount of driving and scouting on roads better suited for ATVs than pickups.  We’ll veg on our next survey here!

 

It’s still dark as Kelly heads uphill to her site, and I pick my way downvalley to my transect, to start my first point as the clock ticks over to official sunrise.  A Dark-eyed Junco pair in the adjacent willow greets the new day with me.

My pre-survey drill: I get to my point, and start filling in the headers of my datasheet.  Transect name, point, date, weather conditions.  I haul out my rangefinder, and double-check where my 50m and 100m boundaries are, then I take a photo of my datasheet headers, then another one (or more) of the transect point.  By this time, if any of the birds in the area were disturbed by my arrival, they should have calmed down a bit.  I note the start time on my datasheet, and start my watch timer.  Go!

Basically, the idea behind our point counts is to record every bird we see or hear from the point during the 10-minute survey period, with no double-counting of individuals within or between points.  Each of those detections is recorded by the minute at which we detect it (e.g., minutes 1 through 10), and the distance band (e.g., within 50m, 50-100m, beyond 100m, and flying over).  Inevitably, birds move over the course of the survey period, so we’re trying to stay aware of where our birds are moving, so we don’t double count them.  It’s critical to use the distance category at which we first detect the birds, so we don’t inflate our density estimates.  I like to think of our point count survey as a snap-shot of the bird community in that first split-second of the survey – it’s just that, given some individuals and species are more detectable than others, we have 10 minutes in which to try to record everybody!

By the time my watch beeps out the end of my count, I have several Spotted Towhees singing, along with a Bewick’s Wren, American Robin, and Mourning Dove.  My Dark-eyed Junco pair has stuck around, too.  I don’t have any unknowns to track down, so it’s time to walk to my next point.  A few meters further on, I hear a Lazuli Bunting male start singing about 75m away.  I record him as an incidental, and keep on downvalley, until I reach #2, and start the process over again.

By the time I finish #10, it’s coming up on 9am.  Usually, I’ll then run our rapid habitat assessments on each bird survey point, as I make my way back to the truck, but we’ll be coming back here in a couple of weeks, so it’ll get done on our next round.  I make my way back up Eldorado Canyon – such a beautiful spot – taking a time-out at the rock arch to drink some more water and enjoy the view.  Happiness.  And then back up to the truck, where I rendezvous with Kelly, and we scout out the road access to our upcoming surveys.  Then camp!  Some paperwork, listening to bird calls/songs, a book and a letter, and dinner.  As the evening wears on, Kelly and I scout out the lower canyon on foot, get acquainted with some more of the plants of the Pine Nut Range, then head back to camp to get things ready for the morning.  As lower Eldorado Canyon falls into darkness, I hear one last loud feeding run by the Robins nesting a bit down the road, and I am out like a light.  Until the next morning, when the whole thing starts up again!

Territory Mapping

Vermilion Flycatcher female on nest in screwbean mesquite

I’ve had some folks ask me about territory mapping, so I thought I’d share a bit about how the Nevada Bird Count does it (the Lower Colorado River project does it slightly differently in order to meet their particular program goals – minor variations on the same theme!).   Territory mapping (we’ll often also refer to it as area searching or spot-mapping) is my personal favorite way to get acquainted with birds of a new region or habitat, and is a fantastic way to learn the natural history of bird and plant communities.  Nothing beats point count transects for the chance to hike and explore and get a wide breadth of understanding of your birds and habitat, and their variation across the landscape – but the area searches are a great way to get depth.  Our plots are of variable size – basically, we want a plot to be big enough that we’re able to have it covered by 9:30-ish in the morning, but small enough that we’re able to have it covered well, and aren’t glossing over sections to get them done on time.  Not surprisingly, therefore, our Mojave Scrub plots are going to be a larger size than our coniferous forest or riparian plots – the former have a lot less habitat structure and fewer birds, so we’re able to cover more ground.  A 300 x 300m plot is fairly typical in streamside vegetation, where there’s a lot of structure.  We visit each plot 8-10 times; often our Mojave Scrub or sagebrush plots are able to be thoroughly mapped within 8 visits, but those extra 2 visits can make a big difference in our more complex plots!

Another area search plot, Sandy Valley

Basically, our surveyors are given an aerial photo overlain with a UTM grid, and on each visit, they will walk through the plot in a different pattern, making sure that they get within 50m of every part of the plot on each walk-through.  The different routes ensure that each part of the plot will get surveyed during the best part of the birding morning on at least one occasion, so we don’t have one location that is always surveyed at 5:30 a.m. and one location always surveyed at 9.  We walk through the plot, looking at and listening to birds, watching their behavior, and marking down their locations on our aerial photo.  Once we’ve finished our initial walk-through, somewhere between 9 and 10am, then we’ll often head back to a perplexing area to spend some more time watching, listening, and mapping.   The 2 biggest things to remember are (1) following individuals and (2) simultaneous detections.  When we find an individual, it’s useful to spend some time with it, marking down the path of that individual’s movement, particularly if it’s a singing male or is exhibiting other territorial behavior.   Do we see any behavior indicating where the nest might be found?  Concurrently, you want to look and listen to determine whether you have any other individuals of that species, and if so, map them too.

Here's one of 3 maps that I filled in during a single visit of my area search plot

At the end of the survey, we’ll end up with a map of all of our bird locations, criss-crossed with lines – solid ones indicating the movements of a particular individual, dashed lines indicate that we had different individuals, along with a few scribbled behavioral notes.  The day’s not done yet, though!  We’ll transfer each species’ locations, lines and notes to a species-specific map, that will eventually encompass all of the data for that species from all of the visits.  Before each visit, we’ll scrutinize those maps, and figure out where the territory boundaries are unclear and where we need to spend some more time.  Then, at the end of our 8 to 10 visits, we’ll draw our territory boundaries, and summarize our findings.

If you squint, you can make out letters marking locations: the first visit is A, the 2nd visit, B, and so on.

The area searches are useful for a lot of purposes – they give us detailed natural history information, and because they provide such detailed location information, they’re excellent at monitoring changes in habitat and bird communities through time, so they’re incredibly useful to monitor habitat restoration projects.  Plus we’re able to use them to do some calibrating of our extensive program of point count surveys – by conducting point counts on the area search plots, we’re able to compare what our point count surveyors record to the mapped territories, which helps us determine detection rates.

You don’t need UTM grids and GPS units to do your own territory mapping, though.  Find your favorite park on (for example) google maps, switch to satellite view, zoom in, and print it out.  With a pencil and your binoculars, you’re now set to map out territories of the bird community – or just a species or two of interest.  When you’ve mapped out a territory, take a look at it  - what does it tell you about that species’ habitat/structural needs?  Where is the nest located relative to the territory boundary?  If a pair renests, with either a replacement clutch or a second brood, do their territory boundaries shift?   As they move along in breeding stages, how do their movements change?   Do their defended areas contract, or expand?  And of course, spot mapping doesn’t have to be limited to the breeding season, you can also see how birds’ uses of various habitats changes across the seasons.  All fun things you can explore with mapping! 

Happy birding,

- Jen