2019 Tree Swallow Status

Summary of Tree Swallow nesting productivity at Buttertubs West Marsh during 2015-2019.

Parameter 2015 2016 2017 2018 2019
Number of boxes3030373030
Number of boxes with eggs (% of boxes with eggs)19
(63%)
20
(67%)
22
(59%)
24
(80%)
21 (70%)
Number of eggs laid109115138135141
Mean clutch size (range) 5.1
(4-6)
5.0
(2-6)
5.1
(1-7)
5.0
(1-7)
5.0
(2-7)
Number of eggs hatched (% eggs hatched)83
(76%)
78
(68%)
82
(59%)
115
(85%)
106
(75%)
Number of nestlings banded (% nestlings banded) 74
(89%)
68
(87%)
69
(84%)
105
(91%)
97
(92%)
Number fledged (% nestlings fledged)61
(73%)
46
(59%)
52
(63%)
62
(54%)
84
(79%)
Fledging rate (young per pair)3.22.12.02.33.0