Friday, May 13, 2011

Unhatched Egg Report

As stewards of the peregrine falcon population in Ohio, it is the Ohio Division of Wildlife's responsibility to foster these birds and protect them. Part of that protection includes monitoring their reproduction. We note when nests succeed as well as when they do not. Given a failure, the responsible thing to do is to evaluate the eggs to determine why they did not hatch. Productivity information such as this is compiled throughout the Midwest and is used to track the species' progress over time throughout the region.

I had an unexpected opening occur in my schedule this morning so I took advantage of it to go ahead and remove the eggs from the nestbox. None of the 5 eggs were fertile. It is probably good then that Durand gave up early vs. sitting on them past the expected hatch date. This way she can get on with simply being a falcon and defending the territory when/if need be. We will hope for a better outcome in 2012!

There was no sign of either falcon while I was downtown today. As usual, we'll keep the cameras up throughout the summer to help monitor the presence of Durand, the male, and any other falcon(s) that may make an appearance. This is the last of the regular nesting season updates however, if/when anything notable occurs I will post it here. Thanks everybody, for your continued support and interest in the ODNR, Division of Wildlife's Columbus FalconCam!

Thursday, May 12, 2011

Incubation is Over

Durand has not shown any inclination to incubate the eggs since the beginning of this week, therefore, it is pretty safe to say we have a failed first-time nesting attempt. The male has not been observed via the cameras so it is unclear whether he is still in the territory or not. His presence--or lack thereof--is actually irrelevant, as even without him she should have continued incubating to term. Her change in behavior is almost surely related to subsiding hormone levels which dictate the behavior to incubate. Because the eggs were not incubated the full time required, had there been any development the eggs would have perished some time ago. In the near future the eggs will be removed from the nest with the intention of determining if they were fertile or not. As soon as that information is known I will post it here.

Meanwhile, Durand continues to make appearances at the nest ledge spending time perched on the nestbox camera housing or the ledge. It is not likely that she will attempt another clutch this year--but then again anything is possible! It is unfortunate that this year's nest did not work out like many had hoped but nonetheless it is still interesting to watch what transpires and learn a little more about the species each season.

Tuesday, May 10, 2011

Eggs Alone

Unfortunately, things continue to deteriorate at the nest. For the majority of yesterday afternoon, overnight and now this morning the eggs have been uncovered. Further, Durand has been away from the ledge more than she has been present.

Earlier this morning she was observed scraping in the corner of the nestbox. This is typical site-bonding behavior that normally occurs prior to nesting and again later in summer after the young have fledged. The fact that she is exhibiting this behavior now is another indication of shifting hormone levels. Even though we categorize these actions as "abnormal" at this stage in the nesting cycle, in actuality abnormal actions can be the norm with a bird that is not yet fully mature as in Durand's case.

We will give her a little more time and continue to observe what transpires. If things stay on this track then in the coming days the eggs will be pulled and examined to determine fertility.

Monday, May 09, 2011

Is There Something Fishy Going On?

Hmmm....well, after an awkward start to incubation then watching as Durand finally got the hang of it and stuck tight to the eggs for ~3 weeks we might have hit a snag. The past couple of days have seen Durand leaving the eggs uncovered on a fairly frequent basis and for extended periods of time. There are several possible reasons for this including, but not limited to:
1) It is possible that we are once more seeing a result of her not yet being fully mature in that her hormone levels are beginning to fluctuate again which would result in less interest in the eggs and her "maternal duties."
2) There is speculation by some that the male is no longer in the territory as he has not been seen via the Falconcams for several days. While it is possible he is still around but just not in front of the cameras, certainly if it were the case that he is gone, Durand would definitely need to leave the nest for longer periods of time in order to hunt for herself, especially if the cached supplies of food are depleted. Were she fending for herself she would need to eat twice a day or so, however, she is leaving the eggs much more frequently than that.

Will this hurt the eggs? There is a point late in the stage of incubation that the eggs are mostly developed and do not have to be incubated as consistently. It also helps that the weather in Columbus has been more seasonable therefore it is unknown if this on and off the eggs then on again will actually be detrimental. This is assuming that the eggs are actually fertile. Don't forget, we also have that unknown issue to consider.

Lack of focus or hungry? Looking a little closer at her behavior we can note that besides her leaving more often, when she is at the ledge she is spending time in front of the ledgecam and perched on the nest box camera housing. Logic would tell us if she was only leaving the eggs to hunt/feed, then when she got back to the ledge she would immediately get back on the eggs. But since she is spending time in view of the cameras but away from the eggs I believe her apparent change in behavior could be a result of the hormone issue vs. simply having to fend for herself. Were the eggs getting close to hatching (and it is really too soon for that) there would be sounds coming from within the egg (chirping, pecking) that would hold her interest and we would then expect her to be standing over the eggs--not perched at the other end of the ledge.

What's the definitive answer to what is going on here? No one knows for sure. All we can do at this point is continue to watch and wait and let what will happen, happen. The best scenario is we see at least 1 egg hatch, or the worst scenario is still good in that the eggs do not hatch but Durand got a lot of good nesting practice in preparation for next year! We should know more in the coming days and will be monitoring her behavior. I will post updates as soon as anything new is definitive.

Wednesday, May 04, 2011

The No Update Update

At week #3 of setting on eggs we are officially into the "doldrums of incubation!" Therefore, it has been awhile since the last post because basically, there has been no change from the last report: Durand continues to do all of the incubation duty. The male occasionally can be seen perched on the ledge or on top of the nest box. Here he is from last weekend:While the male may not be helping with the eggs, he is providing food. Even though there are no visible food exchanges between them, we can assume he is providing because Durand's trips off the eggs are typically very short (sometimes only a few minutes in length). Such a brief respite would not give her enough opportunity to hunt, pluck and eat prey. Because she is gone from the eggs for such little time, she no doubt is getting food from the male either away from the cameras and/or from somewhere he has cached.

I will state again that after an awkward start, once she perfected the incubation technique that she continues to do a good job of staying tight on the eggs. Therefore, the cool, wet weather we have been having in Columbus this week will not affect the development of the eggs, because she is keeping them at a constant temperature regardless of what the actual air temperature is.

Another question I have been asked is are we going to name the male? There are no plans to do so at this time. When a falcon does not have leg bands it makes it very difficult to definitively identify an individual unless there is some distinctive variation in plumage or behavior. This male does not have leg bands and so far, nothing about him has stood out to help us differentiate him from another that could in theory, take his place tomorrow. If he sticks around into next season perhaps by then there may be some type of behavior that we can key in on that will help us have a reasonably good idea that we are dealing with the same individual and we will consider giving him a nickname at that point. Until then I will continue to refer to him only as “the male.”

Should things continue to progress normally we could expect hatching about the 3rd week of this month. More next time on that subject!