2024 Barn Owl update

We thought that 2023 was an odd year for Barn Owls, but 2024 seemed to continue the trend! The very wet spring was perhaps a boom for early grass growth, with a consequent increase in vole numbers. So 2024 saw our highest ever average clutch size (5.4), with three clutches of eight eggs being found.

This didn't necessarily feed through into large broods though, with the average (3.2) very much in line with the last couple of years:

	2015	2016	2017	2018	2019	2020	2021	2022	2023	2024
Sites visited	41	47	64	85	87	106	93	112	127	150
Unoccupied	11	12	23	34	36	43	35	34	29	66
Occupied, no breeding	7	8	5	4	3	4	5	4	10	4
Average clutch size (where observed)	4.6	4.6	5.3	5.2	4.7	4.6	4.5	4.5	4.6	5.4
Average brood size (where observed)	3.5	2.8	3.0	3.3	3.0	3.2	2.8	3.1	3.2	3.2
Chicks ringed	70	47	90	132	119	177	133	189	193	209
Adults ringed/recaught	17/8	14/9	21/14	18/14	16/15	22/17	19/17	20/22	30/24	22/35

The most productive area seemed to be Penwith (average of 4.0 chicks per brood) with the lowest being Roseland (2.4) and East Cornwall (2.9). For only the second year, we also recaught more ringed adults than we ringed new birds, which is very satisfying.

As for movements, the map below shows the origins of birds recaught as breeding birds in nestboxes during the 2024 season. As expected, most of these is short distance dispersal of young birds, on average 8.5km but ranging from 1.7km up to 37.2km.

This only relates to recaptures though, but we unfortunately also hear of many of our birds found dead. In 2024, 11 of our birds were reported dead, including three hit by cars and one that hit wires.