 |
| Colima warbler, Oreothlypis crissalis |
The 2015 Colima warbler census in Big Bend National Park will be conducted May 2 and 3 in the Chisos Mountains. The census is a citizen science project conducted approximately every five years to monitor long term population trends.
 |
| Boot Canyon |
As a refresher for those volunteers who have participated in the past, and some context for those who have yet to participate, here's a summary of the 2010 census:
*
What do biologists from the City of Austin’s Wildland Conservation Division, Travis County Natural Resources, Bat Conservation International, the University of Texas, environmental consulting firms, and several well-known Texas birders and wildlife photographers have in common? They all gave of their time and energy to volunteer for the 2010 Colima Warbler Census in Big Bend National Park!
Every five years with the approval of the National Park Service, two Texas Master Naturalists and nature photographers, Jim & Lynne Weber, organize, plan, recruit, fund, and execute the census. Its’ purpose is to understand the population trends of the Colima warbler (Oreothlypis crissalis), a neotropic songbird that winters in Mexico but is known to breed in the United States only in the Chisos Mountains of Big Bend National Park. The least studied of all North American warblers, the Colima warbler is mainly grayish-brown in coloration, about 4.5 to 5 inches in length, and its field marks include a mustard yellow rump and vent, white ring around the eye, and a rusty spot on the top of the male’s head.
Started in 1967 by then Big Bend Chief Naturalist Ro Wauer, the census has been performed roughly every five years. Jim & Lynne have participated since 1996, and in 2005 they took over the running of the census. In 2010 the census was held on May 7-8, with its’ largest and most qualified volunteer base yet! Over 35 participants traveled to West Texas and were assigned different territories to search for singing Colima warbler males in the mountainous oak-juniper-pinyon habitat. Covering these territories required both perseverance and skill, as many involved bushwhacking through thorny scrub and overgrown canyons or backpacking high into the mountains carrying enough water and supplies for overnight stays. The census itself entailed listening for and locating singing male birds, marking their location on a contour map, and recording other relevant details.
Participants were amply rewarded, however, with nature highlights such as mountain lion and black bear sightings, as well as other bird highlights including band-tailed pigeon, zone-tailed hawk, gray-cheeked thrush, hepatic tanagers, Blue-throated hummingbirds, Townsend’s warblers, and painted redstarts (to name a few). The weather was also a factor, with the first census day being hot, with temperatures well into the 90s, and the second census day being quite breezy and almost 40 degrees cooler. Final results showed that the number of Colima warbler territories was slightly less than average, most likely due to the ever-changing weather factors and recent drought conditions, and a final research report was written and filed with the National Park Service.
All in all, 2010 was a very successful census. A well-attended appreciation dinner was held at the Chisos Mountains Lodge, including special guests Bill Wellman, then Superintendent of Big Bend, and David Elkowitz, the Chief of Interpretation. While everyone received a coveted Colima warbler cap, special awards were given to the volunteer who traveled the furthest to participate (California) and to the volunteer that had the most seniority. Everyone left the park with a satisfying feeling of ‘giving back’ and with lots of stories to tell their friends and family back home!
Before the 2015 survey, participants should refresh their memory of the Colima warbler song either through their favorite phone app or via this link to the excellent audio collection at Cornell University's Macaulay Library:
Macaulay Library - Colima warbler recordings
Check in with us at Stone Cottage #100 (see map below) on Friday, May 1st, between 1pm and 5pm to receive all of your census materials before setting foot on your territory. All participants will be encouraged to hand in their findings at the (complimentary) appreciation dinner at 5pm in the Chisos Mountains Lodge on May 3 (the last day of the census).
Plan on an early start to be on territory in the morning when the birds are more active.
Preliminary Territory Assignments for 2015 Teams (subject to change):
CE = Carol Edwards, Jackie Davis, Alicia Nelson
CoA = Bill Reiner & fellow City of Austin biologists
MM = Mike Millican & Sul Ross students
ND = Nevin Durish, Drew Durish & Brittney Allen
Travis = Paul Fushille & fellow Travis County biologists
GL = Greg Lasley, Chuck Sexton, Liam O'Brien, & Mark Rosenstein
J&L = Jim & Lynne Weber
# Territory Description May 2 May 3
1a Pinnacles Trail up to Pinnacles Pass CE
1b Emory Peak Trail CoA-2
2a Toll Mountain CoA-2
2b Slope of Casa Grande Ridge & Kibby Spring MM
3 East Rim Trail ND
4a South Rim Trail with Travis
Upper Blue Creek Canyon & West Colima Trail
4b South Rim Trail ND
Blue Creek Canyon Trail to Boot Canyon Trail
5 Upper Boot Canyon Trail ND
East Rim Trail to South Rim
6a Middle Boot Canyon Travis
Colima Trail from Boot Canyon Trail to Pass
6b Middle Boot Canyon Travis
Boot Spring Cabin to East Rim Trail
6c Upper Juniper Canyon Travis
Boot Canyon Trail to Juniper Spring
7 Lower Boot Canyon MM
Boot Springs Cabin down Canyon to Pour-off
8 North Boot Canyon MM
Boot Canyon Trail from Emory Peak Trail to Boot Rock
9a Laguna Meadow Canyons CE
Laguna Meadow Trail up to Laguna Pass
9b Laguna Meadow Canyons Travis
Laguna West Campgrounds & Upper Cattail
10 Lost Mine Trail & Upper Pine Canyon Canyon GL
11 Middle Pine Canyon GL
12 Campground Canyon J&L
13 Upper Green Gulch Canyon CoA-1
14 Middle Green Gulch Canyon CoA-1
15 Lower Green Gulch Canyon CoA-1
16 Maple Canyon J&L
Just in case you hadn't yet seen our 'teaser' photo collection of Big Bend, here's a link to that Flickr page, and as a special bonus, the official 'Ode to Colima Warbler Watchers'!
Flickr Page - Big Bend Teasers
SURVEY RESULTS BY TERRITORY & YEAR
Count
Area
|
1967
|
1968
|
1969
|
1970
|
1974
|
1976
|
1982
|
1984
|
1996
|
2000
|
2005
|
2010
|
AVG
|
Delta
|
1
|
3
|
3
|
0
|
2
|
2
|
2
|
3
|
6
|
3
|
7
|
8
|
8
|
3.9
|
4.1
|
2
|
2
|
2
|
2
|
4
|
1
|
3
|
5
|
4
|
1
|
0
|
3
|
4
|
2.6
|
1.4
|
3
|
9
|
10
|
25
|
8
|
6
|
3
|
9
|
8
|
2
|
0
|
8
|
1
|
7.4
|
-6.4
|
4
|
3
|
6
|
9
|
6
|
3
|
2
|
6
|
8
|
4
|
4
|
5
|
1
|
4.8
|
-3.8
|
5
|
4
|
10
|
10
|
10
|
12
|
8
|
9
|
20
|
4
|
10
|
9
|
6
|
9.3
|
-3.3
|
6
|
11
|
13
|
20
|
13
|
9
|
10
|
8
|
6
|
10
|
12
|
12
|
11
|
11.3
|
-0.3
|
7
|
5
|
5
|
5
|
6
|
5
|
5
|
4
|
0
|
9
|
9
|
10
|
5
|
5.7
|
-0.7
|
8
|
3
|
3
|
4
|
4
|
2
|
4
|
2
|
0
|
2
|
7
|
3
|
3
|
3.1
|
-0.1
|
9
|
5
|
11
|
8
|
8
|
7
|
11
|
4
|
6
|
3
|
3
|
8
|
6
|
6.7
|
-0.7
|
10
|
?
|
2
|
0
|
0
|
1
|
3
|
5
|
?
|
4
|
5
|
6
|
6
|
3.2
|
2.8
|
Total
|
45
|
65
|
83
|
61
|
48
|
51
|
55
|
58
|
42
|
57
|
72
|
51
|
57.3
|
-6.3
|
11
|
?
|
?
|
?
|
?
|
?
|
?
|
?
|
?
|
5
|
3
|
3
|
1
|
3.0
|
-2.0
|
12
|
?
|
?
|
?
|
?
|
?
|
?
|
3
|
?
|
2
|
1
|
0
|
0
|
1.2
|
-1.2
|
13
|
?
|
?
|
?
|
?
|
?
|
?
|
?
|
?
|
3
|
0
|
0
|
0
|
0.8
|
-0.8
|
14
|
?
|
?
|
?
|
?
|
?
|
?
|
?
|
?
|
15
|
7
|
0
|
2
|
6.0
|
-4.0
|
15
|
?
|
?
|
?
|
?
|
?
|
?
|
?
|
?
|
1
|
0
|
0
|
2
|
0.8
|
1.3
|
16
|
0
|
0
|
0
|
0
|
?
|
1
|
0
|
?
|
0
|
0
|
0
|
?
|
0.1
|
-0.1
|
Total
|
45
|
65
|
83
|
61
|
48
|
52
|
58
|
58
|
68
|
68
|
75
|
56
|
61.4
|
-5.4
|
? = Area not surveyed
ODE TO COLIMA WARBLER WATCHERS
by Lynne Weber
We came from in and out of state
A sturdy, motley crew
To look for Big Bend’s specialty
As birders often do
The terrain was steep and rocky
Our packs were never light
As we searched the wooded canyons
For a Colima warbler sight
We scanned the oaks and
junipers
And tripped a time or two
Braved the thorns and cactus
spines
Just to get a view
The weather was our fickle
friend
Mother Nature always rules
One day was scorching,
searing heat
The next, windy and cool
We leave with scrapes and
scratches
Sore muscles and some pains
But with memories that are
special
Where rainbows wait for rain!
