Guadalupe Oak Grove Park Bluebird Trail Results
Results for the 2011 Season | |||||
| Species | Broods | First Egg (Estimated) | Eggs | Hatched | Fledged |
| Barn Owl (BANO) | 2 | March 15 | 11 | 4 | 4 |
| Oak Titmouse (OATI) | 2 | March 25 | 15 | 15 | 7 |
| Violet-Green Swallow (VGSW) | 7 | May 23 | 27 | 26 | 23 |
| White-breasted Nuthatch (WBNU) | 1 | March 22 | 6 | 6 | 6 |
| Western Bluebird (WEBL) | 8 | April 13 | 36 | 31 | 18 |
| Totals | 20 | 95 | 82 | 58 | |
The 2011 season results rank among the poorer of the previous seasons. Key negative factors that contributed to the poor results were:
- The poaching of Western Bluebird eggs from one nest box.
- The theft of a nest box with up to 8 Oat Titmouse nestlings.
- The abandonment of eggs by a Barn Owl hen in one of the Park Department's Barn Owl boxes. This is the second season that this has occurred, and is likely due to the box's close proximity to the dog park. The noise from the park likely spooked the hen causing abandonment. The entrance hole to the box has since been plugged to avoid a recurrence.
- The late May and early June winds, and early June rain contributed to the loss of numerous nestings as the adults have a difficult time finding insects to feed themselves and their nestlings in such conditions.
Results for the 2010 Season | |||||
| Species | Broods | First Egg (Estimated) | Eggs | Hatched | Fledged |
| Barn Owl (BANO) | 3 | January 21 | 15 | 11 | 11 |
| Oak Titmouse (OATI) | 5 | March 24 | 30 | 28 | 28 |
| Violet-Green Swallow (VGSW) | 4 | May 17 | 20 | 20 | 17 |
| White-breasted Nuthatch (WBNU) | 1 | March 30 | 5 | 5 | 5 |
| Western Bluebird (WEBL) | 9 | April 16 | 42 | 40 | 29 |
| Totals | 23 | 112 | 104 | 90 | |
Overall, the 2010 season results were good despite the cool and wet spring that we had. As is always the case, several anomalies were noted:
- No Ash-throated Flycatcher nests were even started, although they were seen in the park.
- All three of the Park Department's Barn Owl boxes had nesting Barn Owls. However, the box located next to the dog park was abandoned by the hen after having laid four eggs. The box's close proximity to the dog park and its activity likely caused the nest to be abandoned.
Results for the 2009 Season | |||||
| Species | Broods | First Egg (Estimated) | Eggs | Hatched | Fledged |
| Ash-throated Flycatcher (ATFL) | 2 | May 6 | 11 | 11 | 5 |
| Oak Titmouse (OATI) | 1 | March 22 | 8 | 6 | 6 |
| Tree Swallow (TRES) | 1 | May 11 | 5 | 4 | 4 |
| Violet-Green Swallow (VGSW) | 2 | May 16 | 10 | 10 | 8 |
| Western Bluebird (WEBL) | 8 | April 10 | 40 | 31 | 23 |
| Totals | 14 | 74 | 62 | 46 | |
As was the case last year, several anomalies were noted:
- No White-breasted Nuthatch nests were completed.
- There was a marked decrease in the number of Oat Titmouse and Violet-green Swallow nests.
- The park experienced the first Tree Swallow fledgling from one of the trail's nest boxes.
Results for the 2008 Season | |||||
| Species | Broods | First Egg (Estimated) | Eggs | Hatched | Fledged |
| Ash-throated Flycatcher (ATFL) | 2 | May 9 | 10 | 9 | 8 |
| Nuttall's Woodpecker (NUWO) | 4 | April 6 | 12 | 1 | 1 |
| Oak Titmouse (OATI) | 4 | March 17 | 29 | 26 | 22 |
| Violet-Green Swallow (VGSW) | 6 | May 17 | 24 | 22 | 15 |
| Western Bluebird (WEBL) | 7 | April 15 | 36 | 34 | 18 |
| Totals | 24 | 111 | 92 | 64 | |
The total number of fledglings for the 2008 season was only one more than that of the 2007 season despite having had more eggs, and hatchlings. It is assumed that the continuing lack of rainfall and periods of extremely hot weather are to blame.
Several anomalies from previous seasons were noted:
- No White-breasted Nuthatch nests were completed.
- The park experienced the first Nuttall's Woodpecker fledgling from one of the trail's nest boxes. Only one of twelve eggs in four broods hatched. Most of the eggs disappeared from the boxes.
Results for the 2007 Season | |||||
| Species | Broods | First Egg (Estimated) | Eggs | Hatched | Fledged |
| Ash-throated Flycatcher (ATFL) | 2 | May 17 | 10 | 10 | 9 |
| Oak Titmouse (OATI) | 2 | March 23 | 15 | 15 | 15 |
| Violet-Green Swallow (VGSW) | 7 | May 17 | 29 | 28 | 19 |
| Western Bluebird (WEBL) | 5 | April 8 | 23 | 16 | 10 |
| White-breasted Nuthatch (WBNU) | 2 | March 30 | 12 | 10 | 10 |
| Totals | 18 | 89 | 79 | 63 | |
Given the number of available nest boxes in the park, the 2007 season was the statistically the worst that I have experienced since we assumed the trail in 2002. Most notable was the significant drop in the number of Oak Titmouse (OATI) fledglings-15 vs. last year's 38. Western Bluebird (WEBL) loses were high due to abandoned nests, unhatched eggs, and Hatched that didn't fledge. The early lack of rainfall and periods of hot weather may be to blame.
Results for the 2006 Season | |||||
| Species | Broods | First Egg (Estimated) | Eggs | Hatched | Fledged |
| Ash-throated Flycatcher (ATFL) | 2 | May 22 | 8 | 8 | 8 |
| Oak Titmouse (OATI) | 5 | March 19 | 39 | 39 | 38 |
| Violet-Green Swallow (VGSW) | 9 | May 18 | 36 | 29 | 25 |
| Western Bluebird (WEBL) | 5 | April 14 | 25 | 25 | 24 |
| White-breasted Nuthatch (WBNU) | 1 | March 27 | 6 | 5 | 5 |
| Totals | 22 | 114 | 106 | 100 | |
Although there were losses (abandoned nests, unhatched eggs, and Hatched that didn't fledge), the 2006 season overall was better than last year (2005). Unfortunately, none of the Western Bluebird pairs produced second broods.
Results for the 2005 Season | |||||
| Species | Broods | First Egg (Estimated) | Eggs | Hatched | Fledged |
| Ash-throated Flycatcher | 1 | May 11 | 4 | 3 | 3 |
| Oak Titmouse (OATI) | 2 | March 20 | 16 | 14 | 13 |
| Violet-Green Swallow (VGSW) | 6 | May 24 | 27 | 22 | 22 |
| Western Bluebird (WEBL) | 5 | April 7 | 22 | 13 | 8 |
| White-breasted Nuthatch (WBNU) | 3 | March 14 | 19 | 18 | 13 |
| Totals | 17 | 88 | 70 | 59 | |
The 2005 season experienced more tragedy than previous years.
- One Bluebird clutch of three eggs was destroyed, and House Wrens are suspect.
- One Bluebird clutch of five eggs was abandoned. This can happen if something happens to the female.
- All five Bluebird nestlings in one box were found dead, and House Sparrows are suspect.
- A Violet-Green Swallow nest with a clutch of five eggs was abandoned after the nest box was vandalized.
- Six 1-2 week old White-breasted Nuthatch nestlings disappeared from the nest box. A snake is suspect in their disappearance.
- The female Western Screech Owl that was occupying a Flicker nest box was displaced by European Starlings.
Results for the 2004 Season | |||||
| Species | Broods | First Egg (Estimated) | Eggs | Hatched | Fledged |
| Ash-throated Flycatcher (ATFL) | 1 | May 1 | 5 | 5 | 5 |
| Oak Titmouse (OATI) | 2 | March 14 | 17 | 16 | 15 |
| Violet-Green Swallow (VGSW) | 2 | May 20 | 8 | 8 | 8 |
| Western Bluebird (WEBL) | 4 | April 1 | 16 | 14 | 13 |
| Western Screech Owl (WESO) | 1 | March 18 | 3 | 3 | 3 |
| White-breasted Nuthatch (WBNU) | 1 | March 15 | 8 | 8 | 7 |
| Totals | 11 | 57 | 54 | 51 | |
Last Modified On: 2 September 2011