Behind the Scenes of MRBO Science

The MRBO staff created this webinar to explain in further detail the science behind many of our projects. Dana leads off with the overview and scope of projects. Ethan discusses how data is recorded and some of what we do with it. Zeb follows up with in-depth discussion of our grassland and wetland bird monitoring projects. Erik closes out the webinar with discussion and data from our grassland bird nesting and fall migration survey projects. The webinar ran long, so we didn’t take the time to answer questions live. Check the website for follow-up links and answers to some of the questions we received!

Answers to submitted questions can be found below:

  • Kathy N: How do you keep up on the latest technology and collective knowledge that becomes available to continuously improve your methods and data?
  • Ethan: A large part of our continue improvement comes from practical knowledge in the field. In the case of our data collection methodology, there was no direct solution for our vision. So, we modified existing tech to meet our needs. Later, we used Collector for ArcGIS (typically used for utilities, infrastructure, etc.). We developed our own workflows for formatting the raw data to fit existing analysis methodologies. After presenting on our methodologies internationally, we still have few, if any, peers using our methods. We are still waiting on software developers in leading statistical, coding, and GIS software to develop greater interoperability to meet our needs. Until then, we are still on the frontier!
  • Katie L: Predation by herps vs. mammals.  Do we know the species of herps? 
  • Erik: In order from highest frequency to lowest frequency I’ve seen on the prairie– black rat snake, speckled kingsnake, garter/ribbon snake, prairie kingsnake. There are also some big glass lizards and I’m sure they will feast on eggs.
  • Tim J: Question 1:  If you need to survey an extremely large area, do you sample only a portion of the area and then extrapolate the results?  How do you plan where to survey?
  • MRBO: Our native habitat patches (i.e. study sites) here in Missouri are typically small enough that we cover each site in its entirety with the transect surveys. For example, the largest prairie sites that we survey are under 4,000 acres, so while a site like Wah’Kon-Tah Prairie might take a couple of surveyors a couple mornings, we do the whole thing.  This would not be the case if we were studying huge landscapes such as those out West, where a single ranch can be 80,000 or more acres. 
    • The combination of thorough transect surveys with The Distance sampling protocol do estimate bird densities for the whole site.
    • That being said, we do rotate through sites so that not all wetland and prairie sites are surveyed each and every year; most are surveyed every other year. 
  • Tim J: Question 2: How do you know when you have a good enough sample and can end a survey? 
  • MRBO: As you probably gleaned from the webinar, it depends on the original question and how the study was designed.  Since bird populations fluctuate due to a variety of factors, ideally population monitoring would go on indefinitely (consider the Breeding Bird Survey, which is meant to never end but to track North American bird populations basically forever!).  For something like MRBO’s nest-monitoring project, we intend to parallel the MDC’s study for the planned total of 15 years. This should provide a large enough sample size of nests and be long enough temporally that yearly fluctuations in nest success caused by factors other than our variable (grazing) will be nullified.
    • In a single survey, our transects are a standard length and protocol, where surveys stop when the surveyor reaches the end of a transect
  • Tim J: Question 3: Do you ever use birding scopes rather than binoculars?
  • Erik: Not really, this is because it’s not that realistic to lug a scope around when walking 2+ miles for line-transect surveys. I’ve used a scope to scan for shorebirds on properties but those detections aren’t included in the density estimates because I scoped from the road (off-transect).
  • Katie L: Any clue what caused the spike in number of grassland obligate species in 2014?
  • Dana: We have several hypotheses on that – 1. breeding season 2013 could have resulted in increased populations in some species, coupled with a decent migration (e.g., no major detrimental weather events), but 2. since we began the surveys in 2012 and expanded greatly in 2013, the 2014 numbers could have just been a rebound from lower numbers when we started (which there were no pre-2012 data to compare to).
  • Dan C: How long have you been using the new data entry system?  Were you able to convert old data into the new system
  • MRBO: There have been a few different ways of collecting data. Paper datasheets were retired in 2013. We also at one point used an app called iGIS to collect data in the field, but have moved forward with the Collector app from ESRI for the past few years. All of our data was always stored with ESRI’s GIS Software so there was no conversion or loss as we switched.

Additional Helpful links can be found below: