Irvine Ranch winged residents like the Red-tailed Hawk, White-tailed Kite and American Kestrel are called raptors – however, during the early spring nesting season, they’re also easily monitored indicators of habitat health and recovery after drought and fire.
A new survey of raptor nesting habitats in Limestone Canyon suggests Red-tailed Hawk and White-tailed Kite are bouncing back from both the Santiago Fire of 2007 and recent drought in the region. The survey is conducted by the Irvine Ranch Conservancy with our partners, Bloom Biological Inc., and scientists are watching to see if current populations are in line with counts from last year.
A new survey of raptor nesting habitats in Limestone Canyon suggests Red-tailed Hawk and White-tailed Kite are bouncing back from both the Santiago Fire of 2007 and recent drought in the region. The survey is conducted by the Irvine Ranch Conservancy with our partners, Bloom Biological Inc., and scientists are watching to see if current populations are in line with counts from last year.
“When the top of the food chain is intact, we can be more confident that the whole system is functioning, especially when we see habitat and prey specialists, such as the White-tailed Kite, rebounding as they have been,” says Co-Director of Science and Stewardship Jutta Burger. “The current survey will wrap up in May, and we are looking forward to comparing this year’s final results to those from 2011.”
If the results stay in line with the 2011 survey, it also will be a sign that rodent populations – the main diet of raptors – are healthy and that protection of nesting areas in Irvine Ranch Natural Landmarks is working.
The survey is not a complete census, but rather an inventory of overall population health. In 2011, Bloom Biological reported 25 Red-tailed Hawk nests and 11 White-tailed Kite nests. The survey also documented one Bald Eagle, one Golden Eagle, one Northern Harrier, five Cooper’s Hawks, and six Red-shouldered Hawks in and around the Irvine Ranch Open Space.
If there is a point of concern from last year’s survey, it is that the Red-shouldered Hawk population is still low. The species has not yet returned to numbers that indicate it is also bouncing back from fire and drought. Habitat loss and rodent control have dropped the county’s overall raptor population from their pre-1990s highs, however, extensive collaboration among those who share the vision of healthy Orange County open space provides plenty of reason for optimism.
“It is exciting to see our majestic hawks returning to what were empty territories after the fire,” says Burger.
Volunteers also help conduct the survey each year during the February-to-June nesting season, and some trails are closed during this time as to not disturb the nesting raptors.
However, visitors can easily spot White-tailed Kites, Red-tailed Hawks and Red-shouldered Hawks from open trails in Limestone Canyon. Northern Harriers might also be seen from the trail in the grasslands on Loma Ridge, and colorful American Kestrels may also be seen darting between the oaks or perched and holding lookout for prey. On rare occasion, migrating Swainson’s, Sharp-shinned, and even the occasional Zone-tailed hawk can be glimpsed as well.
The Conservancy offers birding hikes throughout the nesting season, but any hike can be a birding hike if you have your binoculars handy. Check out www.LetsGoOutside.org for activities and programs.
If the results stay in line with the 2011 survey, it also will be a sign that rodent populations – the main diet of raptors – are healthy and that protection of nesting areas in Irvine Ranch Natural Landmarks is working.
The survey is not a complete census, but rather an inventory of overall population health. In 2011, Bloom Biological reported 25 Red-tailed Hawk nests and 11 White-tailed Kite nests. The survey also documented one Bald Eagle, one Golden Eagle, one Northern Harrier, five Cooper’s Hawks, and six Red-shouldered Hawks in and around the Irvine Ranch Open Space.
If there is a point of concern from last year’s survey, it is that the Red-shouldered Hawk population is still low. The species has not yet returned to numbers that indicate it is also bouncing back from fire and drought. Habitat loss and rodent control have dropped the county’s overall raptor population from their pre-1990s highs, however, extensive collaboration among those who share the vision of healthy Orange County open space provides plenty of reason for optimism.
“It is exciting to see our majestic hawks returning to what were empty territories after the fire,” says Burger.
Volunteers also help conduct the survey each year during the February-to-June nesting season, and some trails are closed during this time as to not disturb the nesting raptors.
However, visitors can easily spot White-tailed Kites, Red-tailed Hawks and Red-shouldered Hawks from open trails in Limestone Canyon. Northern Harriers might also be seen from the trail in the grasslands on Loma Ridge, and colorful American Kestrels may also be seen darting between the oaks or perched and holding lookout for prey. On rare occasion, migrating Swainson’s, Sharp-shinned, and even the occasional Zone-tailed hawk can be glimpsed as well.
The Conservancy offers birding hikes throughout the nesting season, but any hike can be a birding hike if you have your binoculars handy. Check out www.LetsGoOutside.org for activities and programs.
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