(almost) Wordless Wednesday

Western Buteos - James Coe

This week's almost Wordless Wednesday image comes from artist James Coe. His work is known to birders from his seminal Eastern Birds field guide for Golden (view here). The above image is taken from an unpublished plate for the Western Guide. As well as his bird illustration, James is also known for his stunning and award winning oil paintings. He is a signature member of the Society of Animal Artists and member of the Society’s Board of Directors as well as being a keen birder. You can view more of his work on his website (here). Thanks to James Coe for the loan of the image!

'Tails' from a Braddock Bay banding station....

Juvenile Red-tailed Hawk - Braddock Bay Raptor Research

Although Braddock Bay, the destination for the forthcoming HMANA Raptor ID Workshop (link here), is best known for spring migration and raptor banding it also annually tracks the movement of dispersing hawks in the late summer, when the Braddock Bay Raptor Research (website here) open their nets again to band mainly young Red-tailed Hawks. As a hawkwatcher, it has always amused me that whilst watching many birds heading south in fall Braddock Bay is still catching the northbound movements of these young birds.

Recently an incredible story of one of these juvenile Red-tailed Hawks reached us at Braddock Bay via Jeff Bouton. Back then he was a bander extraordinaire with Braddock Bay Raptor Research and Braddock Bay Bird Observatory though now he is probably best known to most of you as the birding expert at Leica Sport Optics. Anyway, all the way back on the 3rd of September 1991 Jeff banded a Red-tailed Hawk at Braddock Bay, as part of the annual late summer juvenile Red-tailed Hawk movement. Recently, 22 years later, Jeff received word that the band from that bird was recovered in Pennsylvania after the bird had been found dead. Though somewhat sad, for a hawk that is a pretty good run and in fact this makes it one of the 10 oldest wild Red-tailed Hawks on record. 

Juvenile Red-tailed Hawk - Jeff Bouton

Jeff noted in his message that the day they banded the bird was not a particularly exceptional day for raptors at Braddock as they had captured and banded a mere 10 Red-tailed Hawks. To me that seems pretty good, but then we are comparing it to the kind of days where well over 100 birds have been banded at the Braddock Bay stations. As Jeff noted in his message to BBRR though:  

"...One of those 10 birds however would turn out to be exceptional. One of the largest birds of the day, which took the largest band size acceptable for the species (7D), was just reported found dead near Marion Center, PA. This means the bird lived over 22 years in the wild and makes it the 10th oldest wild Red-tailed Hawk on record!"

Though the above photo of Jeff was taken at the time, it probably isn't of the bird in question as Jeff reckons it to be a little too small. To me it's incredible to imagine this tenacious bird staking out its territory and surviving quite so long in the wild. Out of interest Marion Center, PA is about 250 miles south from Braddock Bay so the bird obviously did a little more wandering before settling down. Data like this shows the continued value of raptor banding. The USGS page on Longevity Records for North American Birds provides a useful educational tool when people ask those inevitable 'how long do they live' type questions about raptors, or any other birds for that matter (visit their page here).

"Mr Grumpy Pants" - Luke Tiller

Coincidentally one of the oldest Red-tailed Hawks in captivity is held by Anne and Paul Schnell. Anne is co-director and heads up the banding efforts at Braddock Bay Raptor Research. Anne and her husband Paul have educational birds and Pauls birds are a major part of the BBRR's educational and outreach events. Their 35 year old Red-tailed Hawk, affectionately called 'Mr Grumpy Pants' still gets called in for publicity duty and my first season at Braddock Bay I ended up posing in the snow alongside Mr Grumpy Pants for the cover of the local newspaper. Grumpy was born in 1978 and is an imprint, as a result of being fed by hand once removed from his nest. As far as I can ascertain, the oldest recorded captive bird died at 36 and a 1/2 years

"You Might Be Getting Excited About Migration, But Not Me!"

“You might be getting excited about migration, but not me” might well express the sentiments of a pair of Red-tailed Hawks that I have been observing closely this year. For the past few years I have been following several pairs of Red-tailed Hawks breeding in the close suburbs of Boston. One pair has been followed year round, as this pair does not migrate. This March I started following another pair nesting on an exposed ledge in a suburban strip mall, and have been observing them and their fledged young very closely.

In late July I was surprised when early one morning we saw the adult male, known as Buzz, break off several tree branches and carry them to a large nest that the pair might have used in 2009, or rebuilt but did not use in 2010. (Data suggests the nest that they might have used in 2009 blew down in October of that year, but a completed nest was discovered in the same tree this March.) Buzz, the adult male, broke off at least three branches and carried them to the nest where they were worked into the foundation by his mate, Ruby. This was unexpected, and I haven’t found any references in the general literature to Red-tails refurbishing or maintaining empty, unused nests in July.

This behavior was reconfirmed a week later when we spotted Buzz breaking off branches and carrying them to the nest where they had raised three young this year. No one in a rather large corps of observers had seen either of the adults back in the nest since the last chick fledged in early June, but Buzz carried several green, leafy branches into the nest and did some point work on the entire nest. He did this under the watchful eye of an unidentified hawk that was occupying a “pillar perch” high on an apartment building overlooking all the territory that Buzz and Ruby had worked this year. Then Buzz and Ruby sat up on the end of the building, facing the unknown Red-tail for about an hour.

Later that same morning we saw both adults break off twigs and carry them into the top of a thick white pine tree, where their behavior suggests they had another, previously known, nest. That would mean they had been working on at least three, possibly four different nests in the month of July, little more than six weeks after their last chick had fledged.

Have readers observed or read about similar behavior in other Red-tailed Hawks? My expectation is that with a very dense population of breeding Red-tails in suburban Boston, this pair will probably not migrate, preferring to stay near their nests all year long. It looks like I will be much more interested in hawk migration this year than they will be.

Migrating Red-tailed Hawks... or Not?

Many hawk watches are still looking for and seeing migrating Red-tailed Hawks. One of the things I especially like about late season migration in the northeast is that the late October/November light on migrating redtails shows them at their very best. Never are the colors richer, warmer, and more beautiful on a Red-tailed Hawk than when bathed in afternoon sunlight in early November.

However, in recent years I have been conscious of another growing movement of Red-tailed Hawks, at least in the greater metropolitan Boston area. More Red-tailed Hawks are breeding in heavily developed inner suburbs – and even the core city – than ever before, not just in the wealthier, greener suburbs. Breeding redtails now occupy virtually every major intersection on the major interstate highways in the region. In at least two intersections in my corner of inner suburbia, multiple breeding pairs occupy territories based on the four separate sets of conspicuous vapor lights, on which they frequently perch; that is, two or three different breeding pairs pair consistently perch on specific vapor lights at one cloverleaf.

I’ve also found that a number of these urban redtails – at least a number of adults – do not leave their breeding areas in the winter. Those birds whose most prominent perches are on vapor lights on major cloverleaves appear to occupy the same perches all year round. Locally nesting redtails who do not use the vapor lights generally do not appear to use their most prominent breeding perches regularly during the winter. They are seen intermittently during the winter, however, periodically checking out their nest sites. This seems particularly true for the adult females.

What happens to the juvenile offspring of these urban redtails? The assumption has been that they disperse and eventually migrate. I have not seen the one apparently still surviving young of my local redtail nest for months.

However, I have seen young of other breeding pairs in the area on the same perches – primarily on the interstates – on which I’ve seen them since they fledged months ago. Will they eventually depart for warmer climes? Or will they become part of the growing urban, settled redtail population?

Other redtails move into the area for the winter, some of whom appear to be western-type redtails. (One bander in southern New England says he has seen dramatic shifts in the wintering Red-tailed Hawk population over the past decade or so, seeing the first and growing numbers of western-type redtails.)

As indicated in the State of North America’s Birds of Prey, published by the Raptor Population Index (RPI), many hawk watches in the northeast have seen a decline in annual redtail numbers over the past four decades. Is this due to there being fewer redtails, or as in the case of the Sharp-shinned Hawk, are more Red-tailed Hawks migrating shorter distances, wintering farther north, or even wintering on their breeding grounds now than in the past? The Christmas Bird Count data for the U.S. from 1960-61 to 2008-09 shows a significant, consistent increase in the number of Red-tailed Hawks seen on CBCs. Are you seeing decreasing migrant redtails over the years, or increases in the number of year-round birds?