by Christiana Manville
photo by Jim Nelson
With all the grief 2020 bestowed upon us there is some good news to share. Volunteers monitored several burrowing owl nests (outdoors and socially distanced, of course) in and around Gilcrease Orchard during the 2020 nesting season. A total of 24 chicks fledged!
Chrisitiana Manville, Partners for Fish and Wildlife Program, U. S. Fish and Wildlife Service, would like to share her letter to the volunteers with you.
Good afternoon Owl Monitors and friends of the Rainbow Owl Preserve!
Thanks to Pat W. for collecting and analyzing the owl monitoring data for 2020 and thanks to all the owl monitors for their efforts. Although it was informal monitoring (due to COVID restrictions), you all did an amazing job, going out and monitoring your burrows. What you did, provides valuable data on the burrowing owls around Gilcrease Orchard and the Rainbow Owl Preserve.
This year 7 out of 8 monitored nests were successful for an 87.5% success rate! Only Burrow 569 on Rainbow Preserve did not fledge chicks. It started off with adults and chicks, but the nest was abandoned on June 21st. With all the burrows counted, we ended up on average fledging 3 chicks per burrow. A total of 24 chicks fledged: 4 in the Orchard, 14 in Rainbow Owl (Jo Marcy 4, Donald Nelson 10) and 6 on unprotected land. Burrow 354 (a non-protected burrow on Jo Marcy that experienced lots of ATV activity) and burrow 575 (artificial burrow in Rainbow Preserve on Donald Nelson) both reported 6 chicks fledged!
This compares well to results from 2019 when 7 nest were monitored, where an average of 4.2 chicks per nest fledged, 5 out of 7 nests were successful (71% success), with 20 chicks fledged: 0 in the Orchard and 20 in Rainbow Owl (Jo Marcy 6, Donald Nelson 14). In 2018, 7 nests were monitored, an average of 2.8 chicks per nest fledged, 6 out of 7 nests were successful (85% success), with 17 chicks fledged: 7 in the Orchard and 7 in Rainbow Owl (Jo Marcy 2, Donald Nelson 5), and 3 on unprotected land.
This was the first year we had no rain events. Last year we had heavy rain that produced about an inch of rainfall, and 2018 also had rain.
Per monitors reports, it seems that we had quite a few more predators this year. (This may be due to the lack of rain and the reduced availability of food, or just more reporting by monitors.) Several monitors this year reported rabbits in the vicinity of the burrows, including at the mouth of some burrows. Coopers Hawks and Red Tail Hawks were also reported at a more frequent rate than reported in 2018 or 2019. A coyote was reported to have jumped the fence and was observed in the Rainbow Owl Preserve on Donald Nelson. One dead adult was found on Donald Nelson and one dead chick was found near burrow 569 along Jo Marcy.
The owls at 575 (artificial) also used burrow 27 (natural), with the chicks first sighted at 575, then moving to 27 as they got older. Burrow 518 (non-protected, natural), also used 576 (artificial) located within the Rainbow Preserve, where the first chick was sighted on 6/19.
Several monitors noted that the first sighting of a chick(s), seemed later this year, and the chicks were more fully developed when they were first spotted. The earliest sighting was 5/21 but 5 out of the 8 burrows (1 burrow did not report a date) did not report a sighting until 6/6 to 6/11. In 2019, the first sightings were 5/21 to 5/30 (with one exception of 6/25), and in 2018 they ranged from 5/11 to 5/20.
I hope you find this information interesting. All the work you do provides important data on the burrowing owls around Gilcrease Orchard.
I am looking forward to working with all of you again in 2021 on this owl monitoring project. Thank you again for your time, energy, and valuable input.