Geese!?!

I checked 19 nests today...found a pair of ospreys on two nests and single birds on 5 nests. Unfortunately I also found a nest occupied by a pair of geese that are incubating. Darn it! But this has happened before, it's becoming a regular thing now...at least one nest every year. I hate to see the ospreys displaced but we will watch and see what happens. The ospreys will probably find another nesting spot nearby. Would love to be there to see how they react when they return! Can't remember if I have told this story here before, but many years ago some geese tried to take over an osprey nest. When the ospreys returned they managed to chase off the geese.The osprey laid their eggs and one day a neighbor called me to report that the osprey chicks were hatching...but I knew they had not incubated long enough so it was not possible for hatching to have occurred. They insisted they could see a little yellow chick up there. But osprey chicks are not yellow! So I ran out there and discovered the ospreys had hatched a gosling! Apparently the geese had left an egg behind. As many of you may know, waterfowl eggs are a little different than raptor eggs. Geese and ducks can lay many eggs and do not begin incubating until they lay the last egg. The eggs can survive a period of time without incubation. However, ospreys begin incubating when they lay the first egg, otherwise the eggs may die.  It was an amazing thing to watch, as they tried to feed it fish and the gosling crawled all over mama osprey and snuggled beside her. They never displayed any hostility towards this odd creature. On day four however, the gosling disappeared...either died of starvation or dehydration, or it jumped off the nest to go be a goose (tho it would have been imprinted so the outcome would not be a happy one for that little guy).

Anyway, more ospreys are returning now. I am frustrated that I don't have more time to spend in the field. Life gets complicated sometimes...

I checked 13 nests today and 3 yesterday...no ospreys seen. But the migration radar indicates there are a lot of birds on southern Minn and Iowa.
Thanks for all the emails  from volunteers telling me....well, nothing! But seeing no birds is also valuable information. Patience!

Extra pair copulation

This time of year is interesting...when a female returns to her nest before her mate, she may engage in copulation outside the pair bond. I have documented quite a lot of this in banded birds. It was previously believed that they "mated for life", but it is actually fairly common for them to engage in extra pair copulation and I believe there may be mixed paternity in a brood. The females who wait for their mate from the previous year to return, do not know if their partner survived migration and the urge to get their eggs fertilized and to breed is a strong one. I have also documented "divorces" ...a term that is anthropomorphic, but explains to people that pairs do split and seek another mate, usually after a failure to breed successfully the prior year. 

My first observation regarding extra pair copulation was many years ago when I was watching a nest that had our oldest male on it. His mate returned and was seen with him on the nest but within a few days of her return, I found her on another nest copulating with another, younger  male for about a week! Then she returned to her nest with the older male to lay her eggs! She had failed to successfully produce chicks with the old guy for several years, so this clearly was her way to improve the odds of producing fertilized eggs! The older male was a good provider, however, which may be why she remained with him.  Interestingly, they produced three chicks that year, but they were predated. The following year she "divorced " the older male and moved in with the younger male.

They're back!

I have seen my first osprey back on its nest! And it's a female. We used to expect that males would return first , but that is not always the case. Sometimes they seem to arrive together and sometimes the females make it back first. We will see if her mate survived migration. She has always been a fairly early return. So osprey season has officially begun. Time for all the wonderful volunteer monitors to begin checking nests! I will get my scope out and begin reading bands.
I have to edit this post as we have now confirmed two ospreys back on their nests...one is a male and one is a female ...both waiting for their mates to show up. I suspect there are other birds back as well, but since the nests we are monitoring are spread out over eight counties, it takes a lot of time and a lot of gas to check them all. This is a labor love with little financial support, so I need to be careful about the miles put on my old hi mileage car. I drove 40 miles and checked four nests today. Most are still empty. As these birds show up, they will usually check their nests / territories but then seek out fishable waters, so our sightings may be sporadic until the lakes open up a bit more. We always need more  help watching over these nests if you are interested in monitoring one thru the breeding season and we REALLY need the publics help in reporting new nests to us. The ospreys are increasingly nesting on cell towers, power poles and lights over ball fields, so keep looking up! 

They will be here soon...

The first ospreys have returned to their nests in New Jersey and in England...so ours cannot be too far behind! Maps of migrating birds show clouds of them south of this cold front that is keeping us firmly entrenched in winter. It seems as if these slow downs in northward movement often brings more ospreys back in pairs...as if they meet up south of here and make the last leg of their journey together. We will see what this year brings. We always need help watching over all these nests ( 88 known nesting territories in 2012), so if you would like to monitor a nest thru the season, email me at osprey.mn@gmail.com.

Funny video

Here is a link to a video of some ospreys...the male delivers a crab to the female instead of a fish...and the reactions are pretty funny. Enjoy!

http://www.youtube.com/watch?v=-d-NudjVUtI&feature=youtube_gdata_player

I find it hard to believe that we are rapidly approaching the 2013 osprey season already! But it's true! They are on the way back to their territories. Last year was so warm in March that we did have some very early sightings in mid month...but most returned at the normal time beginning in late March. With all the snow and frozen lakes, I expect they may begin to show up in the last week of March. Of course since ospreys migrate to south  and central america, they begin their migration north as a result of hormonal changes, not in response to weather.  I believe that if they encounter snow and frozen lakes, making fishing impossible, they slow down and hang out in states south of here until things begin to open up. So weather may affect the final leg of their migration. In my 20 years of studying these birds I have seen the occasional early return...and it may be that they return to briefly check their nesting territory and then seek out open, fishable waters to wait for lakes to open. This may explain an early sighting followed by a period of no activity at a nest. The population continues to grow in the metro area and, as always, I can use help monitoring these nests, and hope that new nests and behavioral observations will be reported to me at osprey.mn@att.net. or osprey.mn@gmail.com.  Thanks again to all who helped me last year, and I look forward to hearing from you all again soon! I couldn't do it without you!