biologia - Studia

A. KONTER
Table 3.
Average full clutch size in the Reeds in relation to the date of platform initiation and
the time span from platform initiation to clutch initiation in 2005 and 2006 (in
parentheses number of clutches).
Date of platform In March 1-10 April 11-20 April After 20 April
initiation 2005 2006 2005 2006 2005 2006 2005 2006
Time span < 6 days
SD
3.67 (3)
1.15
---
---
4.25 (8)
0.89
4.38 (8)
0.74
4.00 (12)
0.80
4.20 (10)
1.32
3.71 (7)
0.49
3.50 (2)
0.71
6-10 days
SD
4.20 (10)
1.03
4.83 (6)
0.983
3.86 (7)
0.69
4.33 (9)
1.22
3.67 (3)
0.58
4.20 (5)
0.48
3.50 (2)
0.71
---
---
> 10 days
SD
4.95 (19)
1.47
4.30 (20)
0.801
4.00 (3)
0
3.75 (4)
0.50
2.67 (3)
1.53
3.50 (4)
0.58
---
---
---
---
Nesting Density and Clutch Size
Nesting density was measured by the degree of clumping (number of
neighbouring nests within 3 m) and clutches were grouped accordingly (Table 4).
In both Reed zones, nests clumped at degree 0 held on average the largest clutches
in 2003, 2004 and 2005, but not in 2006. In 2006, nests most heavily clumped
contained the largest clutches and in nests clumped at degrees 0 or 1-2, markedly
smaller average clutches are observed (Figure 1).
4.60
4.40
4.20
4.00
3.80
3.60
3.40
0 1-2 3-4 >4
2003 2004 2005 2006
degree of clumping
Fig. 1. Average clutch size in relation to degree of nest clumping
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