Friday, May 1, 2015

Musical nests...

It's been quite a week. Another major car repair, AHHHHH. And I have to say I have never seen such a widespread and amazing game of musical nests as I have this year. I am having to return to nests repeatedly to see who is there and figure out where the birds are that were there two weeks ago! One male has been seen, and his bands read, on four different nests, in four different parts of the metro! So I keep returning to where I saw him last, to see who is there now! Some birds have moved to new nests for reasons I don't fully understand. There have been a lot of new, young birds who arrived early and were identified...and then were displaced by the regular residential osprey of past years. Where did they go? And sadly, it seems like a lot of Ospreys who I have been watching for years, many of them middle aged, have not returned to their nests. It takes a lot of time to read and re read bands at all these sites. I am being stretched pretty thin these days. Many nests have begun incubating eggs, and yet, some nests have new residents that are still very much engaged in the courtship process. I watched a spectacular sky dance today...singing the courtship song, doing the dipsy doodle up and down dance with a fish in the air...and then zooming down to the nest, only to mantle over the fish and refuse to share! Ha Ha...won't get the girl that way! She seemed the forgiving type tho.
I love this time of year!

Thursday, April 30, 2015

The Arboretum Cam nest...

Have been watching the Arb cam this morning...looks like some of the chaos has settled down and it is Z3 and an unbanded female who have successfully claimed the territory. However, I am not seeing successful copulation. The male has mounted her back but she did not lift her tail enough so the attempt failed. Sometimes a female who is too young to breed will behave this way. But sometimes a hungry female will also behave this way! Part of the courtship! We will see if eggs are laid or not. Many nests are incubating now.

Monday, April 27, 2015

Asynchrony

Several people have asked why the birds are still copulating after they have already started incubating. Ospreys begin incubating as soon as they lay the first egg. They continue to copulate to fertilize subsequent eggs. Eggs take about 72 hours to be formed, fertilized and pushed out, so they lay the eggs about one to  three days apart. (They typically lay 2-3 eggs. Occasionally there are four.) The chicks will also hatch one to three days apart, so one chick may be as much as six days older than the youngest.  This gives that first chick a head start and a distinct advantage when competing for food.  Alan Poole, who wrote the well known book "Ospreys, a Natural and Unnatural History" says the youngest chick can weight 25-30% less than its older nest mates. This is called asynchronous hatching. Ducks, on the other hand, do not begin incubating until all eggs have been laid, and then all chicks hatch at the same time. This is called synchronous hatching. 
We do see runts on Osprey nests with clear differences in size in the early days, and some of them do not survive, but in some cases, by fledging time they have caught up, and it's hard to tell which chick is the youngest! 
I watched a female lay an egg yesterday. She was upright on the nest edge when I arrived. I was hoping to read bands on both birds so stayed and watched for several hours. During that time she did not leave the nest but moved into the center of the nest and assumed  a hunched over position. She began rocking back and forth slightly, as if she was shifting her weight from one foot to the other and she repeatedly looked  down between her legs. After about 20- 30 minutes of this she began poking around in the nest cup and finally sat down in incubating posture! Then the male came with a fish and she stood up and they both looked into the nest cup, and then he assumed incubating posture! Chicks are on the way!

Thursday, April 23, 2015

Mr 79, the 23 year old Osprey...

Some news about our friend Mr 79, who has nested on the arboretum cam nest for years. He disappeared from that nest last Monday. Today I was out checking nests and saw an osprey sitting on the side of the road...it was 79. I approached with a towel in hopes of capturing him but he flew off. He flew fine, wings are fine. He kept  landing on mailboxes, garbage cans etc...and everytime I tried to get close he flew. He finally made some loops and got higher in the air and soared off over Lake Minnetonka and I lost him. I do not think he is doing well, but he is fully flighted so he can't be caught. Maybe this is the way old birds fail. I hope he is just having a bad day. Somehow he wanted me to find him I think.  Send him good thoughts...and let me know if you see him.
Thanks to all the people who tried to help, bringing boxes, taking photos of his band. I feel sad. I want him to be OK.

Tuesday, April 21, 2015

Osprey deterrent?

So many little dramas going on...I thought this one might make you chuckle, as it did me. A pair of Ospreys built a nest on a large radio tower last year...the company tore the nest down this winter. (You are supposed to have a permit from the state to do this). The birds started rebuilding, so the company went back up there and removed the sticks again and put a fake owl there. Now the Ospreys have a nest halfway built, incorporating the owl! HA HA. People think these birds are stupid...they do know the difference between a real owl and a plastic one. And they can be stubborn!

Sunday, April 19, 2015

A new longevity record for us...

I am happy to report that our old friend Mr 79 is back on the cam nest at the Arboretum. I saw him last evening but wanted to confirm the band in better light. He has set a new longevity record at 23 years of age. He seems very hungry and his mate, 3S was being a little aggressive towards him for not sharing. That will change. I think she has been quite stressed having to defend this territory alone and now 79 will chase away those males and things will be easier for her. Welcome back 79!

Friday, April 17, 2015

Wood ticks and eggs!

It's been quite a crazy few days. I could write volumes but will have to condense it here. After several days of field work, a car breakdown (check engine light on) and an expensive repair, many nests have been visited...and some I still haven't gotten to for the first time. Lots of bands have been read, still many more to read. I like to get as many read before incubation as possible since once they start sitting, you can wait a looooooooong time to see legs. But with so many nests, it's just not possible to read them all during this short window before eggs are laid. I keep plugging away at it. I always say, read bands early and read them often. SO much is revealed by the changes in banded birds on a nest and by who is copulating with whom and who is visiting who! The wood ticks are out...oh my. And we do have our first eggs laid!  I have seen some of my old friends and sadly, some seem to have not survived migration. Our oldest male this year is our 22 year old and he has been waiting for his old partner for weeks. He connected with a few other females during that time, even ones that belonged on other nests. We were about to give up, and then his long time mate finally showed up! This marks their 14th year together!!! Fantastic. Break out the champagne! I have seen a great deal of chaos at a variety of nests, with too many Ospreys flying around. I observed a nest yesterday with two males doing elaborate and very vocal sky dances to impress the lady on the nest. I have watched many nests where a third osprey tried to land on the nest only to be chest butted off, or snapped at. At some other nests I have identified the same two Ospreys meditating in perfect peace as they restore their energies and prepare for what's to come. We have one nest that was taken over by....geese. There are some nests where I still have only seen a single bird, and too many nests that were removed, probably without permits. I have barely begun to put a dent in the work ahead. Much of it is a pleasure, some of it is frustrating. Waiting for two hours for a female to show me her leg bands...and getting no info! AHHHHH. I have to say once again, all my years of work and talking to people have created an amazing network of informants. So many wonderful people drop me a note with some valuable tidbit...so many regular committed volunteer monitors have been exchanging emails, full of conversations about behaviors, observations, questions. So many new volunteers this year are diving in whole hog, buying scopes, visiting their nests several times a week. Wow! And my experienced volunteers are so deeply valued, with all their knowledge about behaviors, band reading and what we call "fanatical patience"...a term stolen from my meditation teacher. It's required to do this work of collecting data and reading bands. Since it is National Volunteer Appreciation week, I extend a deep and heartfelt thanks to all of you who help me watch over these nests. Your efforts are so valued. 
 I am sure more birds will lay eggs soon, and new nests will begin to pop up. Please report any observations of Ospreys carrying sticks, building nests or just hanging out in a new spot. And a special thanks to Clarence and Gladys Osprey, who sent me a gas gift card today. I will be using it to come visit you very soon! So glad you made it back!