Point-count bird censusing: long-term monitoring of bird abundance and diversity in central Arizona-Phoenix, ongoing since 2000
Publication date: 2020-10-02
Author(s):
- Paige Warren, University of Massachusetts-Amherst
- Susannah Lerman, USDA Forest Service Northern Research Station
- Heather Bateman, Arizona State University
- Madhusudan Katti, Department of Forestry and Environmental Resources
- Eyal Shochat, Ben-Gurion University of the Negev
Abstract:
project overview
================
Over the past half-century, the greater Phoenix metropolitan area (GPMA)
has been one of the fastest growing regions in the US, experiencing
rapid urban expansion in addition to urban intensification. This
backdrop provides an ideal setting to monitor biodiversity changes in
response to urbanization, and the CAP LTER has been using a standardized
point-count protocol to monitor the bird community in the GPMA and
surrounding Sonoran desert region since 2000.
The bird survey locations in this CAP LTER core monitoring program
include six general site groupings:
1. ESCA. Forty bird survey locations were selected from a subset of the
CAP LTER's Ecological Survey of Central Arizona (ESCA; formerly
named Survey200) long-term monitoring sites. ESCA sites were located
using a tessellation-stratified dual-density sampling design, and,
as such, span a diversity of habitats including urban, suburban,
rural, commercial areas, parks, agricultural fields, and native
Sonoran desert. Earlier versions of this data package included data
from the ESCA project that was intended to complement the bird data.
However, while positioned in close proximity, the bird survey
locations do not necessarily overlap with the 30m x 30m plot that
constitutes an ESCA sampling location, and leveraging data from
these two monitoring programs should be addressed carefully. ESCA
data have corresponding survey location names, and those data are
available through the CAP LTER and LTER network data portals. At the
conclusion of the 2016 spring survey, fifteen of the ESCA-correlated
sites were discontinued as the core monitoring program refocused its
efforts on desert parks and PASS neighborhoods. Among the deleted
locations were all agricultural and commercial sites, as well as
sites where access had become restrictive.
2. North Desert Village (NDV). Additional bird survey locations were
positioned in treatment areas of the North Desert Village (NDV).
This was a site of intense study on the Arizona State University
Polytechnic Campus in which the CAP LTER converted the landscaping
of small neighborhoods to reflect the dominant landscaping
preferences employed throughout the GPMA. NDV landscape types
include: oasis (NDV-O), xeric (NDV-X), mesic (NDV-M), control
(NDV-C), and native (NDV-N). Monitoring at NDV was discontinued
after the spring 2016 season as research efforts at this site came
to an end.
3. Riparian. While the forty bird survey locations that were selected
to coincide with ESCA sampling locations span a wide diversity of
habitats throughout the GPMA, because of the generally random nature
of selecting those sites, they did not reflect riparian habitats.
Riparian areas are important bird habitat but constitute a very
small area of the GPMA. To address this deficiency, bird survey
locations were established specifically in twelve riparian habitats.
Riparian habitat sub-types include: (1) ephemeral-engineered (EE,
n=4), (2) ephemeral-natural (EN, n=2), (3) perennial-engineered (PE,
n=3), and (4) perennial-natural (PN, n=3). This research was
successfully concluded and these sites were discontinued after the
spring 2016 season.
4. Salt River. Seven study sites along the Salt River as it runs
through the GPMA that were selected as part of a related study (Salt
River Biodiversity Project (SRBP)) were ultimately included in the
CAP LTER's core bird monitoring programs. These sites reflect
continued monitoring of riparian habitat.
5. Desert Fertilization. Beginning with the 2016-2017 winter survey,
six sites at desert parks were added to core monitoring to coincide
with the CAP LTER Desert Fertilization (DesFert) experiment sites.
6. PASS. Beginning with the 2016-2017 winter survey, what used to be a
separate bird-monitoring effort (monitoring in Phoenix Area Social
Survey (PASS) neighborhoods) was incorporated into this core
bird-monitoring program. Eight points were carried over from prior
PASS monitoring, and 28 new points established, resulting in three
bird monitoring locations in each of the twelve PASS neighborhoods.
Visiting these locations each year, versus only in years surrounding
the PASS survey as done previously, provides more data on bird
populations found in the neighborhoods of the CAP LTER study area.
method overview
===============
In a given season, each bird survey location is visited independently by
three birders who count all birds seen or heard within a 15-minute
window. The frequency of surveys has varied through the life of the
project. The first year of the project (2000) was generally a pilot year
in which each site was visited approximately twice by a varying number
of birders. The monitoring became more formalized beginning in 2001, and
each site was visited in each of four seasons by three birders. The
frequency of visits was reduced to three seasons in 2005, and to two
season (spring, winter) beginning in 2006.
Keywords:
urban,
birds,
species abundance,
species composition,
communities,
community composition population studies,
adapting to city life,
parks and rivers aves,
avifauna cap lter,
cap,
caplter,
central arizona phoenix long term ecological research,
arizona,
az,
arid land
Temporal Coverage:
2000-06-06 to 2019-05-03
Geographic Coverage:
Geographic Description: CAP LTER study area: greater Phoenix, Arizona (USA) metropolitan area and surrounding Sonoran desert region
Bounding Coordinates:
Longitude:-112.742 to -111.622
Latitude:33.8814 to 33.2187
Contact:
Information Manager, Central Arizona–Phoenix LTER,
Arizona State University,Global Institute of Sustainability,Tempe
caplter.data@asu.edu
Methods used in producing this dataset:
Show
CAP LTER BIRDING POINT COUNT PROTOCOL Revised December 2014
### POINT COUNTS
A point count consists of one person standing in a specific location for
a fixed length of time at a specific time of day, and counting all birds
seen and/or heard within a specific distance ("Fixed Radius") or as far
as the eye can see ("Open Radius.")
- CAP LTER uses 15-minute observation periods
- Counts are completed within 4 hours of local sunrise (see provided
table for sunrise time)
- Counts are done using the "Open Radius" method
### ADDITIONAL OBSERVERS
The primary observer may be accompanied to the point by an additional
observer. However,only the observations of the primary observer should
be recorded on the data sheet. To avoid any bias that would invalidate
the data collected, the secondary observer should not verbalize, point
out birds, or give any non-verbal cues to the primary observer (e.g.,
looking at a bird with binoculars is a non-verbal cue). The second
observer should position itself in order to minimize disturbance to
birds as well as to the primary observer. Ideally, the second observer
will stand near the primary observer and slowly move around or bend down
so that he/she does not obstruct the primary observer views.
- Please note in the "Site Condition" section of the datasheet if an
additional observer was present during the count.
- If the secondary observer sees a species that the primary observer
did not see, it may be noted in the "Notable additional bird
species" section.
### COUNT CONDITIONS
- The first point count should be started no earlier than
local sunrise. The final point count should be finished no later
than 4 hours past local sunrise.
- Do not conduct point counts in steady or heavy rain, though it is
acceptable to conduct counts in light, intermittent drizzle (be sure
to make note of this in the "Precipitation" section of the
data sheet).
- Do not conduct point counts in steady winds above 20 mph (visual cue
= branches of a moderate size move, small trees in leaves begin
to sway). Make a note of the wind condition in the "Wind" section of
the datasheet.
- In the "Disturbance" section, note if yes or no any type of
disturbance occurred during the count, and describe the disturbance
under the "Site Condition" section of the datasheet. A disturbance
may involve disturbing you, the observer (e.g., a homeowner came and
talked to you), or disturbing the birds (e.g., a cat chasing birds,
garbage truck making lots of noise and flushing birds, predator flew
by and flushed birds, etc.).
- If YOU, the observer, are being disturbed during the 15-minute count
period for any reason, make a note of the interruption in the "Site
Condition" section. Time should be paused for the duration of the
interruption and resumed once the interruption event is terminated.
Redo the count entirely if you are unsure of the time you were
disrupted for.
- Make a note of the overall noise condition for the whole count
period in the "Noise" section of the datasheet.
### APPROACHING THE POINT and FILLING TOP OF DATASHEET
- Park your vehicle at >40m from the bird point.
- Approach the plot as quietly as possible to minimize disturbance to
the birds present.
- In the "Notable additional bird species" section, make note of any
bird species flushed by the approach in case they do not return
during the count.
- Under "Notable additional bird species", note bird species
seen/heard before and/or after the count. Bird species recorded
under this section are species NOT observed during the count but
observed while at the site.
- Stand quietly at plot center for 5 minutes before starting
the count. This is essential to allow any disturbance caused by the
approach to settle down.
- Use this 5-minute settle-down time to fill out the information at
the top of the datasheet, set up the noise meter, and find your
distance brackets (5m, 10m, 20m, 40m) with the range finder. Note
that the range finder MAY be in yards. If so, the conversion of
yards to meters is: 5m = 5.4yrd; 10m = 10.9yrd; 20m = 21.9yrd; 40m
= 43.7yrd.
- Record in the "Site condition" section any unusual circumstances
around the plot, such as construction activity or flooding, or
anything you noticed that have changed since your last visit. Also
note presence of water (or absence of it) at sites where water is
typically present such as at the riparian sites (site code starting
with "EE", "EN", "PE", or "PN").
- Record "Site Obstruction" as the percent of the horizon view that is
blocked by something within a 20-m radius of the point. Record this
every visit, even if it does not appear to have changed since your
last visit. Record in 5% increments.
### CONDUCTING THE COUNT
After the 5-minute settle-down period, set a watch or timer and conduct
the count for 15 minutes. Rotate slowly in place and record all birds
seen and/or heard. For each observation, note the following in the
appropriate column of the data sheet.
Species
- the four-letter (English name) 54th AOU Supplement (2013) alpha
codes if known (see bird list code provided), or write down the
complete common name.
- If the species cannot be positively identified, use the closest
taxonomic affiliation (it is better to record something as "unknown"
rather than guessing). Make sure you look at all the "unidentified"
code options listed on the bird list code provided to pick the most
appropriate code.
Number of Individuals and Distance
- Usually, a single individual bird will be recorded per line.
- Only record a number greater than one on a single line if birds of
the same species are observed very close together, such as a flock
or family group.
- If a mixed flock is observed, put each species on a separate line
and note in the "Notes" column that they were part of a mixed flock.
- Record estimated flock sizes (e.g., "10-20" or "15+") only if you
cannot count them all.
- Write the number of individuals observed in the appropriate
distance columns.
- If a bird moves during the count, record only the distance at which
it was first observed.
- Pay close attention to bird movement to avoid counting birds twice.
- Birds such as hummingbirds should be recorded in the distance column
if they are using the habitat (such as when they are
observed foraging) even if they are not perched per say. However, if
you see them just flying quickly by or chasing each other, then they
should be recorded as FT.
Fly-Throughs (FT)
- If a bird is seen flying through the count area below the tallest
structure or vegetation, and not observed taking off or landing,
record it in the "FT" column only, not in the distance columns.
- See note above regarding when to record hummingbirds as FT.
- High flying birds can be noted as a FT only if they are "aerial
screeners" using the habitat, such as a hawk circling 100 feet
overhead looking for food. Make a note if the aerial screener is
flying higher than the tallest structure.
- You may note in the "Site Condition" section any unusual fly-overs
of birds NOT using the habitat, such as a flock of Pelicans flying
above the city.
Seen (S) or Heard (H) Columns
- Record with a check mark whether the bird was identified from
sight (S) or sound (H), or both. Use caution with similar-sounding
birds like Juncos and Chipping Sparrows, or with mimics and
imitators, like Mockingbirds and Starlings.
Direction
- Record the direction the bird was first observed or heard. This may
mean recording a bird heard to the south (S) even though you were
facing northwest (N/W) at the time.
- Use the cardinal and mid-cardinal points of the compass (N, N/E, E,
S/E, S, S/W, W, N/W) in this column.
### ADDITIONAL INSTRUCTIONS
- After the count is completed and before leaving the site, review
your data sheet to ensure you have filled it correctly: make sure
you have a count and distance for all observations, and that the top
part of your datasheet is complete.
- Record under "Notable additional bird species" section ONLY birds
USING THE HABITAT. This section is to record bird species seen using
the habitat, but not recorded during the count.
- Under the "Site Condition" section, you may note species such as
Cormorants or Pelicans flying high above but NOT using the habitat.
- Record under "Non-bird species present" any non-bird species
observed at the site or fresh signs of non-bird species (i.e.,
coyote scat) at the site
- Wear drab clothing and avoid bold patterns that might scare away
some birds, or attract other ones.
- During the count, do not "pish", "squeak", or use any other methods
to encourage birds to show themselves. This would artificially
inflate the bird densities recorded and invalidate the
data collected. If you want to see a bird you had difficulty
identifying, you can "pish" only after the count is completed.
- Use the 15-minute count period effectively; do not spend precious
time trying to identify a bird that is far enough so that a spotting
scope would be necessary to identify the species.
- Do not start or continue a count if personal safety is threatened in
any way. Notify CAP LTER bird research group managers of any threat
to safety encountered at a research plot.
- If the full 15-minute point count survey cannot be completed
entirely for any reasons (e.g. weather, time limits, safety, etc.),
the count must be re-done entirely and completed at another time
within the season survey window.
### DATA AND COMMUNICATION
- To minimize errors, please review and complete your data sheets
within a day or so after the survey, preferably the day of
the survey. In between others, make sure you did not leave any blank
spaces, review all the alpha codes (if uncertain of an alpha code,
verify it with the bird list code provided or write the FULL common
name), complete your notes and make them concise, and preform
necessary research (listen to calls and/or look at different
field guides) to fill in your uncertain identification(s)
when possible. The datasheets must be clear and easy to read to
facilitate data entry and prevent errors.
- All completed datasheets (reviewed for errors) must be returned to
ASU within two weeks of the last survey completed during
that season.
- To facilitate communication and to aid the supervisor in tracking
project progress and scheduling, make at least one entry per week on
the google+ project resource page – be sure particularly to note if
you surveyed all your assigned sites for the week or if you missed
some (specify which ones), report interesting/unusual sightings and
specify where you saw them, and report any problems (i.e., site
access issues, road closures, safety concerns, scheduling
issues, etc).
Data Files (3) :
Tabular:
46_additonal_bird_species_56724a85166d9f53cf8c8bf79d4aa5e2.csv
Description: additional bird species seen using the habitat but not recorded during the count
Temporal Coverage: 2001-05-05 to 2019-05-03
Column |
Description |
Type |
Units |
site_code |
survey location identifier
|
string |
|
location_type |
survey site type
|
string |
Enumeration:
-
CAPIV: new sites or sites reclassified for CAP IV
-
DesertFertilization: Phoenix area mountain parks that are part of the Desert Fertilization study
-
ESCA: colocated with Ecological Survey of Central Arizona (ESCA)
-
NDV: North Desert Village, ASU Polytechnic Campus
-
PASS: Phoenix Area Social Survey (PASS) study neighborhoods
-
Riparian: Riparian habitat
-
SRBP: Salt River Biological Project
|
survey_date |
survey date
|
date |
Format: YYYY-MM-DD |
time_start |
survey start time
|
string |
|
time_end |
survey end time
|
string |
|
observer_name_part |
truncated name of surveyor
|
string |
|
code |
four-letter alpha code of observed taxon
|
string |
|
common_name |
common name of observed taxon
|
string |
|
Tabular:
46_core_birds_86df2602ec2945732633f78db7fb049d.csv
Description: bird survey sampling details (site, date, time, observer, site conditions, and notes) and birds surveyed (type, number, distance from observer, behavior)
Temporal Coverage: 2000-06-06 to 2019-05-03
Column |
Description |
Type |
Units |
site_code |
survey location identifier
|
string |
|
location_type |
survey site type
|
string |
Enumeration:
-
CAPIV: new sites or sites reclassified for CAP IV
-
DesertFertilization: Phoenix area mountain parks that are part of the Desert Fertilization study
-
ESCA: colocated with Ecological Survey of Central Arizona (ESCA)
-
NDV: North Desert Village, ASU Polytechnic Campus
-
PASS: Phoenix Area Social Survey (PASS) study neighborhoods
-
Riparian: Riparian habitat
-
SRBP: Salt River Biological Project
|
survey_date |
survey date
|
date |
Format: YYYY-MM-DD |
time_start |
survey start time
|
string |
|
time_end |
survey end time
|
string |
|
observer_name_part |
truncated name of surveyor
|
string |
|
wind_speed |
wind speed
|
float |
kilometersPerHour |
wind_dir |
wind direction
|
string |
|
air_temp |
air temperature
|
float |
celsius |
cloud_cover |
percent cloud cover
|
float |
dimensionless |
survey_notes |
notes regarding survey
|
string |
|
human_activity_notes |
notes regarding any human activity during the survey
|
string |
|
wind |
qualitative assessment of wind speed during the survey
|
string |
Enumeration:
-
none: no perceptible wind
|
precipitation |
qualitative assessment of precipitation during the survey
|
string |
|
disturbances |
indication of a disturbance to the surveyor at the survey location during the survey
|
string |
Enumeration:
-
0: no perceptible disturbance to observer or in the vicinity during the survey
-
1: disturbance occurred during the survey
|
sight_obstruct |
percent of the view obstructed
|
float |
dimensionless |
noise_level |
qualitative assessment of noise level during the survey
|
string |
Enumeration:
-
high: high level of noise during the survey
-
low: low level noise during the survey
-
none: no noise during survey
|
site_condition |
notes regarding the condition of the survey location
|
string |
|
non_bird_species |
notes regarding non-bird fauna observed during the survey
|
string |
|
code |
four-letter alpha code of observed taxon
|
string |
|
common_name |
common name of observed taxon
|
string |
|
distance |
relative distance or position of observed bird(s) relative to the observer
|
string |
Enumeration:
-
>40: bird observed forty or more meters from observer
-
0-5: bird observed within zero to five meters of observer
-
10-20: bird observed ten to twenty meters from observer
-
20-40: bird observed twenty to forty meters from observer
-
5-10: bird observed five to ten meters from observer
-
FT: bird is seen flying through the count area below the tallest structure or vegetation, and not observed taking off or landing
|
bird_count |
quantity of the observed taxon
|
float |
number |
observation_notes |
notes regarding bird observation
|
string |
|
seen |
indication of whether the bird was seen
|
string |
Enumeration:
-
0: bird not identified by sight
-
1: bird identified by sight
|
heard |
indication of whether the bird was heard
|
string |
Enumeration:
-
0: bird not identified by sound
-
1: bird identified by sound
|
direction |
direction of the bird
|
string |
|
QCcomment |
quality control comments
|
string |
|
Spatial Vector:
46_core_bird_locations.kml
Description: bird survey locations at select locations in and around the greater Phoenix metropolitan area
Horizontal Coordinate System:GCS_WGS_1984
Geometry Type: Point
Column |
Description |
Type |
Units |
Name |
survey location identifier
|
string |
|
location_type |
survey site type
|
string |
|