Archive for March, 2013

Mar 08 2013

Saturday March 9 at the Aviary

Published by under Books & Events

Aviary promo, March 9, 2013

Come on down to the Aviary this weekend for their Falcons! event.

I’ll be there on Saturday March 9 from 10:00am to 12:30pm to answer your questions about peregrines.

Click on the image above for more information and directions.

(image from the National Aviary website)

 

No responses yet

Mar 08 2013

Gestures

After a week near western gulls in San Diego I got pretty used to seeing individual gulls perched high, watching the others fly by.  Inevitably, the lone gull would throw his head back and give the long call when other gulls flew over. What did he mean?

The “long call” is used in many contexts, as a greeting between mates or a statement about territory.  In this video two great black-backed gulls give the long call when they fight over a fish.  Watch the video and I’ll tell you what I think about their interactions.

Their gestures tell the tale.

  • The hungry gull (HG) approaches, bowed low in a threatening gesture.
  • The eating gull (EG) sees the threat and opens his wings, “Back off!”
  • HG turns away and gives the Long Call:  He hunches over, bows his head, then lifts it high leaning his body at an oblique angle and calling loudly.  You might think he’s not talking to EG because he’s not looking at him.  Far from it!  By turning away he’s avoiding direct confrontation.  Perhaps he’s trying appeasement.
  • That didn’t work.  HG walks past EG without looking at him directly.  As he approaches EG’s tail he gets an idea.
  • Tail pulling didn’t work at all, so the hungry gull bows low (a threat) and walks to the front of EG.  Facing him and opening his wings (again, a threat), he tries to steal the fish.
  • Finally the eating gull has had enough.  The two fight.  EG quickly wins.  Hungry Gull retreats while EG gives the long call in triumph, and then resumes his meal.

What’s the relative stature of these gulls?  My guess is that EG (the eating gull) outranks HG (hungry gull), but HG is willing to test the limits.

 

(Video by littleW007 on YouTube. Today’s Tenth Page is inspired by page 320 of Ornithology by Frank B. Gill.)

No responses yet

Mar 07 2013

Peregrine Watchers Needed at Pittsburgh Bridges

Published by under Peregrines

Peregrine in flight, Delaware (photo by Kim Steininger)

Last year seven pairs of peregrines nested in the Pittsburgh area.  Will there be that many this year?  And where?  The only way to know is by having observers report what they see.

Yesterday Art McMorris sent me a plea for Pittsburgh peregrine watchers.  Of our seven nest sites, four are well monitored (Pitt, Downtown, Tarentum, Westinghouse) but three known bridge nests have no regular observers and three more might attract new peregrine pairs.   You could be the one to adopt a bridge and a pair of peregrines.

Here’s Art’s request:

Dr. Art McMorris, Peregrine Falcon Coordinator for the Pennsylvania Game Commission is looking for people to help monitor several sites in the Pittsburgh area for peregrine falcon nesting activity.  Some of these are sites where falcons are known to be nesting; others are sites where falcons have been observed, but no evidence of nesting has been documented. All would benefit from additional monitoring by local enthusiasts. If you’d be interested in watching any of these sites, please contact Art directly at (McMorris@mac.com) and he’ll send further information about monitoring and about the site.

The sites are:

  • Glenfield, I-79 Bridge (I-79 and the Ohio River).  Arched span from Neville Island to Glenfield.
  • McKees Rocks Bridge (McKees Rocks Bridge Rd. & Ohio River)
  • Monaca-East Rochester Bridge (Route 51 & Ohio River).
  • Pittsburgh, 40th St. Bridge (40th St. & Allegheny River).
  • Rankin Bridge (Green Belt/Rankin Bridge Rd. & Monongahela River)
  • Sewickley Bridge (Orange Belt & Ohio River)

If you live near one of these bridges or regularly pass by, consider being a peregrine monitor.  You might discover a new nesting pair!

Click here for information on last year’s bridge nests.

Art sends his thanks in advance.

 

(photo by Kim Steininger)

p.s.  If you want to monitor the Downtown peregrines, come to Peregrine Quest this Sunday March 10 at 2:00pm.  Meet me at the Market Square Starbucks.  Click here for more info on this event.

7 responses so far

Mar 06 2013

Hard And Easy

Surfbird and Black Turnstone (photo by Dick Daniels on Wikimedia Commons)

Here are two Life Birds who were hardest and easiest to see when I was in San Diego.

The surfbird, on the left, was hard!  He walks on seaside rocks and lets the surf break over him.  The best place to find him is on the breakwater at Mission Bay’s entrance but the day we were there the bird was way down the jetty out of sight.

A few intrepid birders walked the jetty and pointed to the bird.  For this particular Life Bird I was willing to walk the jetty but I didn’t count on how hard it would be.  Without my walking stick I literally crawled over the uneven rocks.   Not fun!  I turned back without seeing the bird and waited onshore for him to pop into someone’s scope.  Fortunately he appeared at a distance.  Even through the scope I felt like I earned him.

The black turnstone was easy.  He also lives on rocky shores but there were many more black turnstones and they were easy to see at La Jolla while walking the beautiful seaside path.

For some reason the surfbird feels more valuable.  ;)

(photo by Dick Daniels on Wikimedia Commons.  Click on the image to see the original.)

One response so far

Mar 05 2013

The Triple Fence

Published by under Musings & News,Travel

Border Fence at Canon de los Sauces, 2012 (photo by Jill Marie Holslin)

Travel is very educational.  Not only are there different birds in San Diego but the threats those birds face are different from what I’m used to in Pittsburgh.  One issue particularly grabbed my attention because we never have to deal with it at home.

Where I come from it’s hard to imagine the wall that defines the southern edge of San Diego County.  Like the Berlin Wall it’s patrolled by armed guards, edged by cleared land for easy enforcement, and in places triple-fenced.

The border has been patrolled for a long time but the Real ID Act of 2005 mandated the border wall and exempted its construction from every environmental law including the Endangered Species Act, the Migratory Bird Treaty Act, the Clean Water Act, the Clean Air Act, and the National Environmental Policy Act.  Exemptions like this bring to mind mountaintop removal in West Virginia.

During design of the Triple Fence, San Diego Audubon and other groups tried to prevent the worst environmental damage but it was impossible to stop the juggernaut.  Now that the wall is up, they’re working with California State Parks and the Tijuana National Estuarine Research Reserve to monitor the wall’s effect on sedimentation, erosion, and invasive plants.

There are lots of problems to monitor.  Here are just two examples.

The fence through Yogurt Canyon, shown above, disrupts the natural drainage into the Tijuana Estuary to the north.  This affects everything that depends on the water, including birds.

At Border Field State Park, shown below, the wall’s construction leveled Litchy Mesa and filled Smugglers Gulch.  There used to be a single fence.  Now there’s a massive valley-fill and all the issues that come with it.
Smugglers Gulch before and during the Triple Fence project  (photos by Jill Marie Holslin)

Ironically, the wall has an unintended consequence.  In the old days workers used to migrate back and forth like the birds — north for planting and harvesting, south to their homes in the winter.

In his 2001 book, Crossing Over, Rubén Martínez described how the patrols even then were ending the return migration.  It’s now so dangerous at the wall that those who get here can rarely leave.

I’m sure that’s not the result the wall’s proponents had in mind.

Read more about the border fence and how it affects the land and people of Tijuana and San Diego in Jill Marie Holslin’s blog, At The Edges.

(photos used by permission of Jill Marie Holslin from her blog, At the Edges. Click on each image for more information.)

4 responses so far

Mar 04 2013

Thrashing It Out

Published by under Songbirds,Travel

California thrasher (photo by Alan Vernon from Wikimedia Commons)

We’re starved for thrashers in Pittsburgh right now.  Of the eight species in North America only one, the brown thrasher, occurs in the eastern U.S. and he’s away on migration.  All the rest are western or southwestern birds, several of which occur in California.

This one has “California” in his name.  He doesn’t migrate — in fact he hardly moves away from his birthplace — so if you want to see him you have to be in California or northern Mexico.

The California thrasher loves dense desert chapparel but is sometimes found in scrubby or suburban habitat where he encounters a bird whose habits are quite similar.

Northern mockingbirds eat the same food and forage in the same way as California thrashers.  Both are highly territorial so when a mockingbird moves into a thrasher’s territory constant warfare ensues.

Imagine the two contestants hopping and lunging.

Hey, Mr. Mockingbird, watch out for that beak!

Fortunately for northern mockingbirds, few of them like dense chaparral so these species are usually in separate places.

Good for the thrasher too.  What a waste of energy to be constantly thrashing it out!

 

(photo by Alan Vernon from Wikimedia Commons. Click on the image to see its original)

No responses yet

Mar 03 2013

Target Bird

White-tailed Kite (photo by William Parker)

When I registered at the San Diego Bird Festival I asked to exchange one of my pre-scheduled bird tours because I was desperate to see this Life Bird, the white-tailed kite.

The trip I wanted was full but David Kimball introduced me to local bird leader Susan Breisch who knows the county well.

Susan was so helpful!   She asked to see both my target bird list and my tour schedule, told me the likelihood of seeing my target birds, and suggested places to find them during my unscheduled time.

As usual some species are a challenge, others are surprisingly easy.  For instance…

I would love to see a mountain bluebird but they travel in flocks that move around a lot.  Their reported location one day may be different the next.  This behavior reminds me of the white-winged crossbills visiting Pittsburgh this winter whom I’ve been unable to find.  Hmmmm!

The ferruginous hawk is on my wish list, too, but it only visits the grasslands in winter and even then it’s not plentiful.  Again, you have to be at the right place at the right time and you have to get lucky.

However, white-tailed kites are easy!   They hang out in river valleys and can be found year-round in Rose Canyon where they nest.  In fact, I might even see one on a walk from my hotel.

Oh boy!

 

p.s.  The San Diego Bird Festival is great!  Excellent tours, helpful friendly people, unbeatable weather.  I highly recommend it!

 

(photo by William Parker)

7 responses so far

Mar 02 2013

The Birdiest County

Brandt's cormorant (photo from Wikimedia Commons)

To my untrained East Coast eyes this bird looked like an odd double-crested cormorant, but it’s actually a Brandt’s cormorant, a common bird of the Pacific coast.

This weekend I’m in the bottom left corner of the United States at the San Diego Bird Festival held in one of the two “Birdiest Counties” in the continental U.S.  (Los Angeles County is the other.)

According to San Diego Audubon, “the County boasts the largest bird list of any similarly sized area in the United States at almost 500 species.”   With this honor also comes the distinction of having “the greatest number of endangered, threatened, and sensitive species than any comparable land area in the continental United States.”

San Diego is able to set these records because it has at least 11 habitat zones including coastal scrub, desert, mountains, salt marshes, wetlands and ocean, far outranking my land-locked home in Pittsburgh.

In my first hour of birding — just walking near the hotel — I saw long-billed curlew’s, marbled godwits, an orange-crowned warbler (singing!), Anna’s hummingbirds, black-crowned night-herons, and Heerman’s gulls.  By now I’ve seen 94 species including this life bird, Brandt’s cormorant.

When you compare San Diego’s checklist of 501 birds to Allegheny County’s 316 species (including vagrants), I know I’ll find a “lifer” around every corner.

 

(photo from Wikimedia Commons. Click on the image to see the original.
Quotes are from the San Diego Audubon Society website.
)

3 responses so far

Mar 01 2013

The Cheapest Way To Go

Golden-winged sunbird (photo from Wikimedia Commons)

In Africa sunbirds fill the ecological niche that hummingbirds fill here.  Like hummingbirds, they feed on nectar, have long down-curved bills and come in beautiful iridescent colors.  The main difference is that sunbirds perch instead of hover.

Like hummingbirds, sunbirds also pugnaciously defend their nectar sources and spend a lot of time chasing and fighting.  What is the advantage in doing this?  Doesn’t it cost more energy than peaceable feeding?

In 1975 Gill and Wolf studied the energy expended by territorial golden-winged sunbirds in Kenya.  Their results were a bit surprising.  It costs less energy per day to defend really good nectar sources than it does to feed at undefended low-nectar flowers.

Here’s the math:

  • Undefended flowers have less nectar because so many birds are feeding at them.  Foraging burns 4 kilojoules of energy per hour but it takes 8 hours to get enough food.  8 hours * 4 kilojoules/hour = 32 kilojoules burned.
  • Defended flowers have twice as much nectar so it takes only 4 hours to get the same energy.  4 hours * 4 kilojoules/hour = 16 kilojoules burned while foraging.
  • Defending these flowers is energy intensive (12.5 kilojoules/hour) but if it doesn’t take much time it’s worth it.  If it only takes 20 minutes to defend those flowers in that same 8 hour period the results are:   0.33 hour * 12.5 kilojoules/hour = 3.7 kilojoules burned in defense.
  • What does a territorial sunbird do with all that extra time?  He sits around and watches his flowers.  3.7 hours * 1.7 kilojoules/hour = 6.3 kilojoules spent sitting.
  • Therefore his total energy expenditure is 26 kilojoules, a savings of 6 kilojoules in 8 hours.

That’s why hummingbirds are so belligerent at our feeders.  They’re making the calculation that defending a great food source is the cheapest way to go.

(Credits:
Photo of a golden-winged sunbird from Wikimedia Commons.  Click on the image to see the original.
Today’s Tenth Page is inspired by page 310 of Ornithology by Frank B. Gill.
)

No responses yet

« Prev

Bird Stories from OnQ