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7 9 11 13 15 17 19 21 23 25 27 29 31
Temperature (Degrees Celcius)
Mean #
Monarc
hs
(± S
td.
Err
)
Long Point Bird ObservatoryMonarch Migration Monitoring
Long Point Bird ObservatoryMonarch Migration Monitoring
Monarch counts highest during south-west headwinds, with Beaufort wind speed 2-3 (8-16 km/hour)
Long Point Bird ObservatoryMonarch Migration Monitoring
0
100
200
300
400
500
600
700
800
9008
-1
8-4
8-7
8-1
0
8-1
38
-16
8-1
9
8-2
2
8-2
5
8-2
8
8-3
1
9-3
9-6
9-9
9-1
29
-15
9-1
8
9-2
19
-24
9-2
7
9-3
01
0-3
10
-61
0-9
10
-12
10
-15
Ave
rage
# M
on
arch
s
Date
Breakwater
Tip
Long Point Bird ObservatoryMonarch Tagging (2008-2009)
Question:
Is the number of monarchs stopping over, and length of stop-over, related to:
1. Site (tip vs. breakwater), 2. Habitat (nectaring plant
abundance)3. Monarch health (how fat?)4. Weather conditions5. Date
• Improve population estimates• Develop criteria to assess importance of stop-over sites• Develop guidelines for designation of “critical habitat”
• Tagged 1420 in 2008, 1712 in 2009• Recaptured 11% in 2008, 6% in 2009 (1 day - 2 wks)• More males caught early in season• Healthier monarchs caught later in season
2008: Stop-over Duration
Wind Direction
Sto
p-o
ver
Dura
tion (
Days)
2
3
4
5
Headwind Tailwind
Wind Speed
Sto
p-o
ver
Dura
tion (
Days)
2
3
4
5
Light Strong
Fat/Newly Emerged Skinny/Old
Fat monarchs stayed longerEffect of wind speed/direction not statistically significant
Recapture rate constant
2009: Recapture Rate
• Stop-over duration constant (mean 1.7 days)
• Recapture rate varied with condition:• Fat/Newly emerged butterflies were re-captured less frequently (2.6%) than skinny/old butterflies (9%)
No effect of habitat on stopover durationmonarchs did not stay longer at Tip: suggests flower abundance affects how many stop, but
not how long.
No effect of date on stopover durationmonarchs aren’t staying longer when breeding
still occurring (late August)
Year
Me
an
Pre
dic
ted
Da
ily C
ou
nt
0
200
400
600
19
95
19
96
19
97
19
98
19
99
20
00
20
01
20
02
20
03
20
04
20
05
20
06
20
07
20
08
20
09
Annual Population Estimates (1995-2009)
Long Point Bird ObservatoryMonarch Migration Monitoring
0
200
400
600
800
1000
1200
1400
1600
19
95
19
96
19
97
19
98
19
99
20
00
20
01
20
02
20
03
20
04
20
05
20
06
20
07
Year
0
2
4
6
8
10
12
14
16
18
20Long Point Mexico
Annual In
dex
# H
ecta
res O
ccupie
d