Raptors Take Flight Over Hawk Hill

Hawkwatchers with the Golden Gate Raptor Observatory scan the skies and surrounding viewshed for migrating raptors.

Jessica Weinberg-McClosky GGNPC

Hawkwatch teams from the Golden Gate Raptor Observatory dedicate their autumn months to tallying over 19 species of migrating raptors that soar over Hawk Hill, while banders capture and release raptors in order to garner insight into their movement patterns as well as potential threats to their populations. The consistent effort of GGRO volunteers to tally raptors provides the only statewide index of rises and falls in raptor populations, and demonstrates the value of citizen science.

 

A red-tailed hawk soars overhead. These raptors have broad and rounded wings, and are most easily identified by their a short, wide red tail.

Will Elder NPS

Raptor Migration

Just like humans, raptors often migrate in order to seek better living conditions. During fall migration, they travel south to reach warmer wintering grounds. Hawk Hill is a heavily trafficked stop on this journey, likely because raptors generally avoid crossing over large bodies of water like the San Francisco Bay. The Marin Headlands instead offers ideal migration conditions – warm thermals of air that emit from the land allow raptors to gain altitude, updrafts off of the Headlands’ craggy terrain provides lift, and geographical features like coastlines and mountain ridges present a natural line to follow during migration. Hawkwatchers can see more than 1,000 birds in just 6 hours of spotting from Hawk Hill. Among these birds, the most common visitors are turkey vultures, red-tailed hawks, Cooper’s hawks, and sharp-shinned hawks.

 

The Thrill of Hawkwatching

As I am coming to terms with the fact that we might get fogged out, I see a part in the clouds making way for some blue skies. There, I see it. A red-tailed hawk, one of the most commonly banded at the Golden Gate Raptor Observatory. As I lift my binoculars to focus on it, so do my spirits and I think, “It has begun.” -- Laura Echávezá, GGRO Intern. 
 

 

Eyes to the sky! Hawkwatchers search for raptors on a rare sunny day at Hawk Hill.

Jessica Weinberg-McClosky GGNPC

Threats to Raptors

GGRO aims to inspire the preservation of California raptor populations, and hawkwatching efforts alert raptor ecologists of population declines as they occur. Raptors are faced with numerous threats, including poisons, collisions, and habitat loss. You can help by avoiding rat poison and waiting to trim trees until the nesting season has passed in late fall.

Yet interannual variations in climate due to climate change is by far the biggest threat to raptors. Shifts in temperatures and seasons can complicate intersections between species and desynchronize their life cycles. These shifts in phenology, or seasonal timing between plant and animal life, will have a ripple effect on the food chains of many raptors. Changes in the timing of seed dispersion, for example, can negatively impact insects, which impacts songbirds, and finally impacts the raptors that feed on songbirds. If climate patterns continue to change at exponential and unprecedented rates, many raptor species may not have sufficient time to adapt, and phenological mismatches may eventually undo the webs of their ecosystems.

 

Hawk talks are the best way to learn more about raptor migration at Hawk Hill. Consider attending them in the autumn months!

Phoebe Parker-Shames GGRO

Get Involved

• Hawk talks and raptor releases occasionally occur for the public to view throughout the autumn months, check here for scheduling or email [e-mail] with any additional questions.
• Curious to learn what kind of bird photobombed your picture of the Golden Gate Bridge? Check out the Daily Hawk Count to discover what birds shared the sky with you during your visit.
• The best time to see raptors at Hawk Hill is during midday hours (from 10 am to 2 pm) in September and October. Bring binoculars, water, and dress in layers. Make sure to record your sightings in your Marin Headlands Junior Ranger Book, and bring it to rangers to get sworn in as a junior ranger.
• Citizen science opportunities allow us to assume ownership over our shared environment and form lasting connections with wildlife and wild lands. Consider becoming a GGRO volunteer.