Tuesday, May 01, 2012

Now for the rest of the story...

As my blog friends know, I have erected an osprey platform in my river tributary in self-defense against osprey who wanted to build a nest on my boat.  More than 20% of the population of osprey in and around the Chesapeake Bay depend on these artificial platforms for nesting.  Approximately two thousand breeding pairs nest in the Chesapeake Bay area representing 20% of all osprey in the United States, so my platform is of importance.

Now pay attention to what follows below so that you can enjoy my notes on the nesting behavior of Fred and Ethel in the coming months.  There will NOT be a test but the clue to the back story from the prior post is at the end.  (If you have to read and run, this will be up and you can come back later!)

At 3 years osprey mate for life returning to the same nest each year. Some osprey live for 30 years, but most do not.  Pesticide residue was responsible for severe population decline in the 1950s.  In the late 1960’s DDT was determined to have caused a 2-6% annual decline in the population of these fish hawks due to eggshell thinning. Pesticide runoff today still impacts insects and shellfish that fish eat and that impacts osprey also by decline in food.  

Osprey parents also bring junk to the nest which endangers the fledglings. Little birds have been caught in holes in bubble wrap and swallow pieces of plastic among other dangers. Fishing line is notorious for causing death in osprey. Please throw away your trash and pick up trash on the shorelines!

Osprey arrive in my area in late February and early March as did "my" Fred and Ethel. They mate and dance and nest build. In mid-April they lay their eggs and begin the brooding process. Normally 3 eggs are laid but rarely all three survive. The female sits for 38 to 42 days on these eggs and then the birds hatch in early June. Osprey feed on surface schooling and spawning fish. Healthy and abundant fish populations are key to osprey survival. A healthy male must capture 5 to 8 medium sized fish EACH day to sustain himself, a mate, and three young osprey. I know fishermen who use radar, artificial smelly bait and do not have to expend such energy to fly and they could not keep up this pace. 

Predators of the osprey fledglings include raccoons, rats, crows, great blue herons, bald eagles, and horned owls. All of these live in or near my neighborhood but the raccoons would find it very difficult to reach the nest off-shore. Powerful great horned owls and agile golden eagles have killed adult osprey for food as well. But osprey have also been known to kill herons and owls. It is a bird eat bird world out there. The other day I saw our red shouldered hawk scare the female osprey to the side of the nest briefly and I am guessing he was looking for fledglings. Since she still has eggs he flew away.  I am hoping the hawk finds plenty of other food this summer.

Fred and Ethel still shriek and fly off the nest when we use the dock, but I can only hope they grow to accept us as most osprey eventually do.  I have read that we should gradually increase our presence.  I think that, like crows, osprey are smart enough to remember a face and she knows I was the one who kept her from successfully nesting last spring.  Maybe she will never forgive me ? :-(

Now that you have read through the whole treatise on osprey, I will admit that as some of my readers guessed, the back story is that the female is banded.  Banding took place a few years ago with osprey on this river.  I also learned that with powerful scopes the ornithologists have been able to read the band numbers from a distance to collect their data and do not have to capture or wait for a dead bird.  My next step is to contact the scientist that did the banding who has moved to the northern part of the state and see if they are interested in my observation.







15 comments:

Bossy Betty said...

Such incredible birds! I am sure the scientists will be thrilled to hear from you.

Brian Miller said...

that is really cool all that you have learned...i would def be a bit anxious too, to hear what the scientist has to say....very cool....

Celia said...

Magnificent birds, and so exciting to find a banded one to report on. I wish them well in their raising of offspring. I've never seen more than one baby out of a nest and hope this one is luckier. So fun to follow along with you.

Wendy said...

What a treat to be able to see these birds. We have bald eagles that mate in our area, but not close enough where I can just look out and see them any time. Nature is amazing.

Hilary said...

This is going to be a very interesting summer for you. And us. Thank you for that.

Nezzy said...

Wow, what an amazin' story 'bout a beautifully amazin' bird. You certainly scored on catchin' that band!

God bless and have a great day sweetie!!! :O)

Mystic Meandering said...

What a great story! I am so glad you are chronicling all this. It's fascinating and so wonderful that you are in such a spot to watch the wild life! I love reading it all.

Jenny Woolf said...

I think they will be interested in your observation. Nice story. And beautiful photos, as ever.

Granny Annie said...

Your continued intriguing tale of the Osprey is one of my most enjoyable journeys through blog world.

Peruby said...

Face recognition? Really? That is amazing.

Betsy from Tennessee said...

Bird eat bird,huh???? Gosh---nature can be hard for all critters I'm sure...

Glad you can watch the Ospreys and hopefully the little ones... That is always so much fun to watch our birds, isn't it?

I have been watching the Eagles with their 3 little ones --on the web cam in Iowa. Very interesting..

Hope you have a great day.
Hugs,
Betsy

Kat said...

That is just so cool!
My son was asking me questions about osprey just yesterday. I'll have to bring him back to your blog so I can read it to him. Thanks! :)

Mage said...

This is absolutely fascinating.

Dave King said...

A really great post. Huge thanks for it - and the back story. How fortunate you are to have these birds so close!

Pauline said...

Following this saga with interest - the news channel I watch here has a camera trained on a peregrine falcon nest on the station roof. Just watched those chicks hatch! There is such satisfaction in watching wildlife. They teach us much.