consequences of parental care: male and female eastern bluebird delivery of food to chicks india...
Post on 20-Dec-2015
214 views
TRANSCRIPT
Consequences of Parental Care:
Male and Female Eastern Bluebird Delivery of Food to Chicks
India Peek Jensen: REACH ProgramSpring Lake High School
Mentors: Dr. Kathy Winnett-Murray and Dr. Greg Fraley
animals.nationalgeographic.com/.../bluebird.html
Introduction
• From a scientific standpoint– Parental effort is a large part of understanding
how the environment influences the social and mating systems of animals.
• From a wildlife management standpoint– We want to know how changes in the
environment are influencing the sustainability of this population through behaviors like parental care.
http://poemsandprose.blog.co.uk/2006/11/14/more_tessimond~1328098
Background
• Eastern Bluebird (Sialia sialis)– 1970s-80s EB
population in MI plummeted.
• Reproductive Habits– Typically
monogamous– 4-6 eggs– Primarily insectivorous
http://poemsandprose.blog.co.uk/2006/11/14/more_tessimond~1328098
http://www.pbase.com/uncledave/image/74457096
J.H. Campbell Complex, Consumers Energy
Bird Composition in Nest Boxes Since 1992
Species Composition of Bird Species, Percent of Total Active Nests
0%
20%
40%
60%
80%
100%
1992
1994
1995
1997
1998
1999
2001
2002
2003
2005
2006
2007
Year
Pe
rce
nt
BC
HW
TS
EB
http://poemsandprose.blog.co.uk/2006/11/14/more_tessimond~1328098
Research Questions
• Difference between sexes in food delivery?
• Do differences affect reproductive success?
• How is this related to nest defense?
http://poemsandprose.blog.co.uk/2006/11/14/more_tessimond~1328098
0
2
4
6
8
10
12
Pecks Hovers Dives
Behavior
Individuals
Female
Male
Male and Female Eastern Bluebird
http://poemsandprose.blog.co.uk/2006/11/14/more_tessimond~1328098
flickr.com/photos/12369485@N05/1361846793/ www.nebraskabirds.com/bluebirds.php
Male Female
What I did…
• Behavior Observations
• Nest Checks
http://poemsandprose.blog.co.uk/2006/11/14/more_tessimond~1328098
http://poemsandprose.blog.co.uk/2006/11/14/more_tessimond~1328098
Example of Behavior Data Sheet
http://poemsandprose.blog.co.uk/2006/11/14/more_tessimond~1328098
Wilcoxon z=0.15698, df=1, P=0.8753, no significant difference between males and females in delivery trips per minute
Delivery of Food to Chicks by Male and Female
F MSex
0.00
0.05
0.10
0.15
0.20
Del
iver
y T
rips
Per
Min
ute
http://poemsandprose.blog.co.uk/2006/11/14/more_tessimond~1328098
Wilcoxon z=-0.1778608, df=1, P=0.8588324, no significant difference between male and female load sizes
F MSex
0.0
0.2
0.4
0.6
0.8
1.0
Pro
port
ion
of L
arge
Loa
ds to
Tot
al L
oads
Proportion of Deliveries That Were Large Insects
http://poemsandprose.blog.co.uk/2006/11/14/more_tessimond~1328098
Wilcoxon z=-2.6679113, df=1, P= 0.0076324, significant difference
between males and females in brood time per minute
Brood Time by Male and Female
F MSex
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
Bro
od T
ime
Per
Min
ute
Delivery Rates to Young and Old Chicks by Male and Female
F MSex
0.00
0.05
0.10
0.15
0.20T
rips
Per
Min
ute
over 8 days old1-8 days old
Chick Age (Days)
Mann Whitney U (Females)= 12.50, df=1, P=0.1227; Mann Whitney U (Males)= 33.00, df=1, P=0.2764, no significant difference between male and female delivery rates to young and old chicks
http://poemsandprose.blog.co.uk/2006/11/14/more_tessimond~1328098
Energetic Tradeoff in Parental Care
http://poemsandprose.blog.co.uk/2006/11/14/more_tessimond~1328098
High
0
Energy available for self-maintenance, reproduction
Energy spent in nest defense, vigilance
Energy Spent 100
Ene
rgy
Cos
t
Conclusion
• Males and females exhibit similar effort in feeding chicks, both in the number of deliveries to the nest and the relative size of those food loads.
• Although responsibilities may differ at different stages of chick development (e.g. brooding vs. feeding) the overall effort appears to be similar, just as in the equal effort males and females show in nest defense.
http://poemsandprose.blog.co.uk/2006/11/14/more_tessimond~1328098
Acknowledgements
• REACH Program• Dean of the Natural Sciences Division at Hope
College, Dr. Moses Lee• Mentors, Dr. Winnett-Murray and Dr. Fraley• Fellow Research Students: Joel Evenhouse,
Jillian Greshel, Jacquelyn Randolet, Tim Paver, Brian Puls, Joel Evenhouse
• Mrs. Schanhals, Spring Lake High School• Consumer’s Energy
http://poemsandprose.blog.co.uk/2006/11/14/more_tessimond~1328098