Sunday, February 15, 2015

2015 Colima Warbler Census in Big Bend National Park

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!  

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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!