Richard and Diane Van Vleck Personal Pages
The Home Habitat

2014 Barn Owl Nesting
Barn owls nested in box 2 on the barn again this summer. The first of 4 eggs was laid on 5/14 and the nesting was uneventful. Although a female had entered the new box "1" several times, there was no second pair nesting this year.  The visitor to box 1 was likely the same female nesting in box 2.  I had finally converted the silo to a chimney swift shaft, which precluded the second pair from nesting there again or the male from using the silo for his day roost.

Nestling barn owl on perch with vole
barn owl nestlings
barn owl young in box
7/18/14
7/21/14
 
nestling barn owls
barn owl nestlings
7/23/14
7/26/14
 
Tyto alba nestlings
barn owl nestlings
7/27/14
7/31/14
 
barn owls in nest box
barn owls
8/5/14
 
8/9/14
 
older nestling barn owls
barn owl
8/12/14
 
8/14/14
 
older barn owl nestlings
barn owl nestlings ready to leave nest
8/17/14
 
8/20/14
 
nestling owls on perch
barn owl youn on perch
Nestlings venturing out on perch
 
Nestlings waiting for food
 
owlets nearing fledge time
barn owls ready to fledge
barn owls ready to fledge
 
The nestbox perch allows room to flap
 
Continuous video monitoring of barn owl prey brought to nest

Prey provisioning was recorded on continuous video each night, beginning the first night the female left the box to resume hunting. This ensured that all prey items recorded were consumed only by the nestlings.

 
Table of barn owl prey provided each day
barn owl prey brought to the nest
The missing data on Aug 3, 4 and 12 was due to video being overwritten or a momentary power failure stopping the recording. In one case, a spider continually wove it's web across the lens in the early morning. Also, nights with few prey were due to prolonged rain, making hunting less than ideal.
2014 barn owl nesting - Number of prey brought to nest
Beginning the night the female left the nest box to resume hunting
DATE 8pm 9pm 10pm 11pm 12pm 1am 2am 3am 4am 5am TOTAL
7/6/2014     1 1 3   3 2     10
7/7/2014           1 2 3     6
7/8/2014       1   3 3 1     8
7/9/2014         4 4 1 1     10
7/10/2014       2 1 2 1 4 1   11
7/11/2014   1   1 1 3 2       8
7/12/2014     1 1 5 3 2       12
7/13/2014   1   1 2 2 2       8
7/14/2014   1 1 1 2   1       6
7/15/2014   1 2   2 3 2 4     14
7/16/2014     1 2 1 1 3 2     10
7/17/2014     1 1 3 3   2     10
7/18/2014     2 2 2 3 3 2     14
7/19/2014   2   1 2 2 1 3     11
7/20/2014         2 2 2 3 1   10
7/21/2014         4 1 4 1     10
7/22/2014         1 2 1       4
7/23/2014     1 2   2 3 1 3   12
7/24/2014       1 3 4 2 1     11
7/25/2014       3 5 2 2 1 1   14
7/26/2014       1 2 2   2     7
7/27/2014         3   1 1 2   7
7/28/2014       2 2 3 4 2 1   14
7/29/2014   2   1 2 2 2 2     11
7/30/2014   1 2 1 1 2 4 1 1   13
7/31/2014         1 3 4 3 1   12
8/1/2014     1   2 4   1 2   10
8/2/2014       1   1 2 1 1   6
8/3/2014                     0
8/4/2014                     0
8/5/2014       2 3 2 2       9
8/6/2014       2   3 3 1 1   10
8/7/2014     1 4 2 4 2 3     16
8/8/2014     1 3 2 1 1 2 1   11
8/9/2014       2 2 4 2 2     12
8/10/2014       3 1 3 2 2     11
8/11/2014       1 1     1     3
8/12/2014                     0
8/13/2014   1   1 1 3 3 3     12
8/14/2014   1 1 1 3 2 1 1     10
8/15/2014   1 1   2 2 2 1     9
8/16/2014   1 2   2 1 1       7
8/17/2014       2 1 2 1       6
8/18/2014     1   1 1 1       4
8/19/2014         1 5         6
TOTAL 0 13 20 47 78 93 78 60 16 0  

2015 - No Barn Owls!

A prolonged snow cover in the previous winter, including a layer of ice had kept the meadow voles safely under cover, which may be the reason that no barn owls have been seen or heard since December, 2014. Nest box monitoring, beginning in January, 2015 showed no owl visits.  The boom and bust cycle of meadow voles every few years has been well documented by many sources and can be linked to nesting success of barn owls the following year.  However, I have never been able to judge such a boom and bust cycle of voles on our property. There were numerous vole trails exposed when the snow melted and our resident foxes seemed to do quite well. But, barn owls are not equiped to break through deep snow and ice to reach their prey.

The conventional thought is that barn owls often starve to death during such weather.  But, another possibility is that the owls resort to hunting rodents in surrounding barn yards and feed lots where bare ground is exposed and mice and rats are present.  These barn yard rodents are often poisoned with the second generation rodenticides, including brodifacoum.  The mice continue to live for several days, while consuming more of the poison bait - enough to kill a barn owl. 

Whatever the fate of all our barn owls, nest box video monitoring will begin this week (Feb 2016). The ground is still snow-covered, but our cat ventures out for an hour or so each day and frequently comes back with a vole. Hopefully, at least one pair will use one of the owl boxes again this year.

2016 Still no barn owls! - While both barred owls and great horned owls are heard in the area, there has been no sign of a barn owl yet. This has been a mild winter with almost no snow cover as of Feb 14, 2017. Still hoping!


2014 Barn owl prey study
2012-2013 barn owl nesting
2011 barn owl nesting
2011 barn owl prey cam
2006 barn owl polygamy
2010 barn owl nesting
2003 barn owl nesting
2003 barn owl prey cam
The attic barn owl nest
Living with barn owls
The barn owl nest box
An interior barn owl box
Barn owl electrocution
The Barn Owl
2014 barn owl nesting - 2017 update 

2010 - 2014 Northern flicker nestings
2014 house wren gourd use
2014 - A dramatic loss of many types of insects
barn swallow artificial nest cups
2014 barn owl nesting - prey study
A new barn swallow shelter for 2013
2010 barn owl nesting
2010 Update
Entire site index (outdated)
Starling traps
Using blinds in the home habitat
Providing perches for birds
Providing snags for wildlife
The ugly young maple
2001 - 2013 nest cams
Use of tomato cages as hunting perches by insectivorous song birds
Vultures, beetles and the resurrection of life

Species of interest in our yard - photos and articles
barn owl American kestrel purple martin barn swallow Eastern bluebird
tufted titmouse Eastern phoebe yellow shafted flicker tree swallow chimney swift
house wren big brown bat Carolina wren brown thrasher catbird
Eastern wood-pewee
cedar waxwing Northern mockingbird
Blue-gray gnatcatcher
turkey vulture
Yellow warbler Acadian flycatcher

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