a geographical evaluation of nesting substrate for the puaiohi, … · 2017. 12. 13. ·...
TRANSCRIPT
A Geographical Evaluation of Nesting Substrate for the Puaiohi,
Myadestes palmeri
Ruby Hammond1, Lisa Crampton1, Pauline Roberts1,2
1Kaua‘i Forest Bird Recovery Project, Hanapepe, HI 2Sapphos Environmental, Inc., Pasadena, CA
Puaiohi
• Population estimate
- 800 individuals
• Habitat Preference
- Streams
• Nest Substrate
- Cliff walls along
streams
Photo credit-Robby Kohley
Halepa‘akai Study Area
Natural Preferences???
Puaiohi Nest Wall Puaiohi Nest
Methods:
• Nests - located from 2007-2009
• 8178m total nest wall length (n=132*)
-Used vs. unused
-Number times used
-In Territory vs. Outside
• Surface cover
• Shrub cover
• Tilt degree
• Stream distance
• Nestwall height
• Cliffwall height
Results-Used vs. Unused
• 38% used
• Mean nest height = 4.9 ± 2.8 m (N = 78)
Χ2 = 3.9, n=132, p=0.049
0
2
4
6
8
10
Me
an N
est
wal
l H
eig
ht
(m)
Mean Nestwall Height for Used vs. Unused Walls
Used
Unused
Models for Walls Used vs. Unused AICc Δ AICc Weight
Nestwall height 174.7 0 0.612
Tilt 177.3 2.56 0.171
Nestwall height, shrub class 178.7 3.61 0.101
Shrub class 179.8 4.88 0.054
Stream distance, shrub class 181.5 6.42 0.025
Nestwall height, surface class 182.1 6.85 0.020
Surface class 183.4 8.32 0.010
Surface class, tilt degree 184.5 9.21 0.006
Nestwall height, surface class, shrub class, strea surface distance, tilt degree 187.9 11.08 0.002
Χ2 = 3.9, n=132, p=0.049, SE = -0.13 ± 0.07
Results-Number of Times Used
0
1
2
3
4
5
6
7
8
9
0 5 10 15 20 25
# Ti
me
s W
all U
sed
Nestwall Height (m)
Number Times Used vs. Nestwall Height
F 1,48 = 6.48, p=0.014
Results-Number of Times Used
Model of # Nests for Used Walls AICc Δ AICc Weight
Nestwall height, shrub class 164.7 0 0.42
Nestwall height, surface class 165.3 0.6 0.311
Nestwall height, surface class, shrub class, tilt degree, stream distance 167.4 2.7 0.109
Surface class 168.4 3.7 0.066
Shrub class 168.4 3.7 0.066
Nestwall height 170.4 5.7 0.024
Stream distance 175.6 10.9 0.002
Tilt degree 176.8 12.1 0.001
Results-Walls In and Out of Territories
0
5
10
15
20
Clif
fwal
l He
igh
t (m
)
Cliffwall Height Inside Territory vs. Outside Territory
Inside Territory
Outside Territory
X2 = 2.60, N=126, p = 0.11, b= -0.09 ± 0.06
Models of Walls in Territories vs. Outside AICc Δ AICc Weight Cliff height 96.9 0 0.351
Stream distance 98.3 1.45 0.170
Cliff height, surface class 98.9 2.06 0.125
Cliff height, shrub class 99.7 2.78 0.087
Tilt degree 99.9 3.04 0.077
Cliff height, tilt degree 100.1 3.23 0.070
Cliff height, tilt degree, surface class 101.2 4.34 0.040
Shrub class 101.4 4.49 0.037
Cliff height, shrub class, tilt degree 101.9 5.02 0.029
Cliff height, surface class, tilt degree, stream surface 103.5 6.61 0.013
Conclusion • Used nestwalls taller than unused
• Increase in use = increase in nestwall height
• Taller cliffwall inside territories
Photo credit- Lucas Behnke
The Future
• Wall data
• Occupancy surveys
• Fruit and vegetation surveys
• Telemetry
• Combine efforts
Photo credit-Lucas Behnke
Thank You!
• Field Biologists!!!
• State of Hawaii, Division of Forestry and Wildlife
• U.S. Fish and Wildlife Service
• U.S. Geological Survey
• Pacific Cooperative Studies Unit