May 11, 2007
Second and Third Eggs
We now have our second and third eggs! Normally osprey clutches are two to three eggs in size, so we're very pleased with the size of the current clutch. If a fourth egg does come (and sometimes they do), it could arrive on Saturday or Sunday. Personally I'd rather the ospreys stopped at three because they started nesting so late. If a fourth egg was laid and the chick managed to survive in the nest, it would have little time to build up its flying/fishing skills before migration season in September.
For those keeping track, here is our 2007 scorecard:
1st egg
Laid: 5/4/7
Possible Hatch: 6/11 or 12
2nd egg
Laid: 5/7/7
Possible Hatch: 6/14 or 15
3rd egg
Laid: 5/10/7
Possible Hatch: 6/17 or 18
On May 7, we heard from a volunteer who was at the Refuge, and they said that an osprey did make a dive at the nest while the mother was sitting on the first egg, but the father was able to chase it away. So right now we’re feeling good about our parents and their ability to defend the nest.
Miscellaneous News:
I also wanted to pass along some miscellaneous osprey news. We have word from the famous osprey nest at Loch Garten in Scotland that EJ has laid the first egg in her second clutch. If you remember, her mate Henry had returned late from migration to find eggs already in their nest (after EJ mated with another). Henry then kicked the eggs out since they were not his, and we've been waiting to see if poor EJ could produce another set, even though second clutches are pretty rare. But now it looks like she's on her way. What a bird!
Technical News:
And now some technical talk: Folks have asked about the Osprey Cam refresh time on our website. We plan to shorten the refresh time right before the eggs will likely hatch. The reason we have to juggle the cam times is because our satellite dish company limits how much traffic we can upload in a given week from both cams. If we go over that limit, they shut us down, so we have to be careful with our refresh times, and since the eaglets are close to fledging, we don't want to alter their cam time right now. Note that this is not related to how many people are watching -- it just relates to how many individual images we upload each minute from our dish. Once the osprey-egg hatching is closer, the eaglets will be spending less time at the Eagle Cam nest, so we will extend the Eagle Cam time a bit so we can shorten the Osprey Cam time.
Also, I wanted to mention that our Friends of Blackwater cam technician has left for Italy. He'll be gone for two weeks, so keep your fingers crossed that we don't have any major equipment malfunctions in the field. :-)
International Migratory Bird Day:
On May 12, many countries around the world will celebrate International Migratory Bird Day, which is a time when people can learn more about the unique needs of migratory birds. At Blackwater Refuge on May 12, we will be holding a free Bird Walk at 8am and a free Eagle Prowl at 10am at our Visitor Center, and we welcome those who will be in the area.
Ospreys in the Chesapeake Bay region (where Blackwater Refuge is located) are migratory birds, with most of them migrating to Central or South America sometime in late August or September. When our ospreys migrate, they will do so separately, and while the parents will return next March, the chicks will stay down south for an additional year before returning to Blackwater to breed.
The theme for the 2007 International Migratory Bird Day is "Birds in a Changing Climate." The reason for this theme is because while much press is being given to how global warming -- or climate change -- will affect people, not as much time is spent talking about what rising temperatures will mean for migratory birds.
Global warming presents many challenges to birds as they try to adapt to warming trends that appear to be occurring at a very fast rate. Some items to consider are the following:
- A warmer planet will intensify droughts and increase the number of forest fires, which burn habitat used by birds
- Rising temperatures will increase glacial melting, which will make sea levels rise and flood wetland areas where birds and other wildlife raise their young.
- According to a report by Cornell University, spring is now arriving a week earlier than it did 40 years ago in the northeastern United States, and while this extends the growing season for farmers, it could disrupt the symbiotic relationship that birds have with breeding insects and flowering plants, as migratory birds often time their return to coincide with the availability of the local food population.
- The increase in carbon dioxide pollution is turning the oceans more acidic and is beginning to reduce marine populations, which will diminish the food supply of coastal and ocean birds.
- The ranges of some state birds could shrink or shift outside the states they represent. For example, as many as 33 states could see significant reductions in American Goldfinches in the summer, and at some point Baltimore Orioles may no longer be found in Maryland. Ultimately some songbird species will not be able to adapt and will die out.
- If temperatures increase enough, certain bird species will stop migrating altogether during the winter, which could lead to increased competition for food in their breeding territories.
In global warming circles, Blackwater Refuge is a bit of a celebrity -- but not in a positive way. The reason for this is because Blackwater Refuge is considered one of the prime examples of how a warming planet can impact coastal areas. The current rate of sea-level rise in the Chesapeake Bay is three times the historical rate and appears to be accelerating. Since 1938, about one-third of the marsh at Blackwater Refuge has disappeared or been "claimed" by the Chesapeake Bay and surrounding waters. The aerial shots of Blackwater Refuge below give you a vivid image of how much marsh was lost to open water from between 1938 and 1989.
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This marsh loss has been brought on by several factors including subsidence (gradual land sinking); erosion; invasion by a non-native, marsh-destroying rodent called nutria; and by rising sea levels.
The U.S. Geological Survey has studied the effect of sea level rise in the Blackwater Refuge area and the model developed for their assessment forecasts that most of the Refuge will be in open water in approximately 50 years.
So what can be done to save the marshland? The U.S. Fish and Wildlife Service, along with a collection of partner agencies, have worked hard to remove the nutria (which were introduced before the Refuge was established), and are now working to restore the marsh plants that were eaten by the rodents. In addition, the USFWS is also working with local officials to find funding to bring in safe dredged material to build up the wetlands so they will be less susceptible to the rising Bay -- something that has proven to be successful in the past. But these types of projects are very expensive, and conservation money these days is in short supply throughout the country.
Further complicating the situation is the rapid pace at which warming is occurring. According to the U.S. Geological Survey study, "The projected rates of inundation due to sea level rise are thought to exceed the capability of the ecosystems to respond to increasing water depth and salinity, thus limiting the availability of critical habitat and triggering a need for expensive engineered schemes for restoration."
The point of sharing this information is not to depress our cam watchers, but to point out that we are seeing the effects of global warming around us right now, and it's time for nations, industries, and individuals to take meaningful action to slow global warming. Even if birds and other wildlife can physically adapt to the changing temperatures, the ecosystems where they breed and raise their young might undergo such drastic changes that the wildlife can no longer live there. And as humans move into more areas that were once wild, it means wildlife will have fewer options when it comes to finding a new home. Patricia Glick, an expert on climate change with the National Wildlife Federation, sums it up best: "Climate change on top of fragmented habitat is the straw that breaks the camel's back."
Below are several links that offer some additional information if you'd like to learn more about the problems and the possible solutions:
- Global Warming and Birds - Audubon PDF fact sheet
- Birds in a Changing Climate - Int'l Migratory Bird Day PDF fact sheet
- Climate Change, Wildlife, and Wildlands - a PDF fact sheet that covers climate change in the Chesapeake Bay region and at Blackwater Refuge, and also discusses what can be done.
- Habitat Displacement and Sea-Level Change: The Blackwater Model
Until next time,
Lisa - webmaster
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