Thursday, July 15, 2010

Ruby-throated Hummingbird nest

A wee cup of hummers, scarcely visible from more than a few feet away.

The other day, a friend casually mentioned that there was an active Ruby-throated Hummingbird nest in his yard, and said yard was right along the route that I would be driving later that day. Not one to miss such an opportunity, I made the scene.

The hummer nest was high in the boughs of a grand old Black Maple, Acer nigrum, and as nearly always is the case, it was saddled to a stout horizontal branch. Hummingbirds virtually always shingle the exterior of their nests with lichens, the better to blend the structure with its surroundings. And blend it does. The dominant shingling lichen on this nest is Green Shield Lichen, Flavoparmelia caparata, and it does an admirable job of masking the nest when seen from below or from the side.

Fortunately, there was one of those old-school TV antenna towers next to the house, enabling us to scramble onto the roof. From that vantage point we could see right into the nest, and I spent a few moments making some photos.

Not much to a hummer's nest in terms of size, but don't be fooled - they are architectural marvels. The two tiny eggs are no larger than your pinky fingernail, and at that point the nest is much less open at the top. It nearly folds over the eggs when Mrs. Hummingbird is not atop them, performing incubation duties.

Because Ruby-throated Hummingbirds use lots of cobwebs to lace the lichens and plant down into their neat little cups, there is a heavy dose of elasticity to the structure. This flexibility allows the cup to expand to accommodate the rapidly growing youngsters, once they pip themselves free of the eggs. Indeed, the adult female had to be rescued - twice! - after she managed to tangle herself in some large spiderwebs in the garage. Should you see hummers busily hovering about eaves, windows and the like, that's probably what they are doing - gathering silken strands of web for their nest, which will be somewhere close at hand.

Prickly litte babies, perhaps a week old. In an especially amazing demonstration of the magic of birds, these rather ugly little hummerlings will soon enough transform into the miraculous feathered helicopters that rival any flying machine on earth in their winged prowess.

Come fall, they'll strike out to the south, and then head over 500 miles of open Gulf of Mexico waters and on into Central America. If all goes well for them, they'll likely be back to breed within a relative stone's toss of this Black Maple tree.


Mary said...

Jim, takes my breath away. I've had a dozen circling my head on the deck but have never seen an active nest. Lovely photos! I hope to share some of my own one day.

Lisa at Greenbow said...

You were up high. Worth the climb to see such a sight.

flux biota. said...

that's amazing! and so small!

Ruth said...

Amazing photos. Love your article too. You give us all the details.Thanks.

Peg said...

these are really amazing photos. Thanks so much for sharing. Hummingbirds hang out in my backyard in our garden, but I've never seen a nest. :)

Crafty Green Poet said...

oh that is so amazing, what an incredibly beautiful structure

Russell Reynolds said...

Great article. Still hoping to stumble across a nest here. Was watching a mink out back here this morning.

David said...

Great blog!

When I saw this I knew I had to leave a comment. What an amazing experiece to witness hummingbird nestlings! Thank you for going to great heights to document it and share it with others.

Julie Zickefoose said...

Coming late to the party as usual. Thankful to see this post. Jim, I've been studying RTHU nestling development with the help of some of Nina's day-by-day photos and my own life drawings, and I can say with confidence that these nestlings are at Day 12. Surprising, I know, given that they're still all prickly, but their development is extremely slow compared to that of warblers and sparrows, which are flying by Day 12! These can expect to spend another week in the nest at least, fledging around Day 20-21. Can't think of a non-cavity-nesting Ohio bird that stays in an open cup nest that long. Thanks for climbing out on the roof, man!