People and Birds Gone Home – Delaware Bay 2007
We wanted to get a late catch of sanderlings before the season ended. Most of the team had already left for their homes all over the globe: Humphrey, Phil and Alice to England; Clive, Susan and Peter to Australia; Pablo and Victor to Mexico. Now it was down to the core group, Steve, Jeannine, Bill and Mandy with Dick who was due to leave the following day. It seemed that the birds, too, were mostly gone. Kathy, Ron and Bill flew the entire bayshore on Tuesday and found only a few thousand birds, mostly sanderlings in the Villas area. I had hoped to find them for a late catch but by the next day they too had left. We would not be trapping — the season was over. In all the years of working on the Delaware Bay stopover I found it strange for everything – birds and people – to be gone so completely.
But it’s best when the birds leave this way: at least it suggests that they have all have made sufficient weight and are on their way to the Arctic. The last few seasons haven’t been so clear. Only a couple of years ago nearly 3,000 knots remained in the bay until well after the first week of June. We have also had years when few knots have achieved adequate departure weight (about 185 grams) by the end of May, which is the time by which they need to reach adequate departure weight if they are to have a good chance of breeding successfully. God help those birds. If the Arctic spring is cold or if late storms hit the breeding areas when birds have just arrived, those that are poorly prepared will have a tough time. The best that can happen is they fail to breed; the worst is that they will die.
This was not one of those years, though the situation is far from satisfactory. The full story has yet to be told, but in New Jersey Dan Hernandez has reported that horseshoe crab egg density fell lower than last year for the first five weeks of the egg survey. Densities averaged about 1,800 eggs per square meter, the lowest in the six years of the survey and far lower than the estimated 40,000 eggs per square meter in the early 1990s and the figure considered necessary for recovery of the bird population. The persistent northwest winds that pounded the NJ bayshore may have lowered the count by creating wind driven waves against the Cape Peninsula shoreline and deterred the crabs from spawning. But eggs densities were low on the Moores Beach to Gandys Beach segment as well. These beaches face south and were not affected by the northwest winds.
Kathy and her team reported about a thousand fewer knots than last year. There are complications that may have caused her to miss birds, particularly in the timing of the counts. But the great value of them is that they have been carried out in the same way every year for the last 21 years so the trend will be true. We have yet to hear of the results of the crab spawning index conducted by Delaware and New Jersey Divisions of Fish and Wildlife.
So there it is. Any reasonable person would have to admit that nothing has improved for shorebirds on the Delaware Bay; if anything, conditions are worse. Our team hopes for the best, but considers that no improvement, particularly when numbers are at such a low level, is bound to lead the bird populations into renewed jeopardy. They may not finally go extinct because of problems in Delaware Bay; that may happen because of something natural but unexpected, such as bad arctic weather, hurricanes, or disease outbreaks. Those will be the proximate causes of extinction, but the ultimate cause will be the lack of improvement in the ecological condition of the Delaware Bay. As things stand, it is clear that until there are more horseshoe crab eggs in the bay beaches during May, the bird populations are unlikely to increase. Unless they increase, they will remain vulnerable to the proximate causes of extinction mentioned above.
I can’t say enough about all the people who helped us this season. Our team of professional volunteers is an inspiration to all. By supplying the team with dinners and arranging field trips to Pinelands, Bear Swamp, the Meerwald and Wheaton village, Citizens United provided the team with rewarding experiences that they will never forget; leaving them, like the birds, in better condition than they when arrived. The NJ Natural Lands Trust, NJ Division of Fish and Wildlife, Conserve Wildlife Foundation, and the National Fish and Wildlife Foundation provided the funds and logistical underpinnings for the whole project. Finally the NJ Division of Fish and Wildlife and Conserve Wildlife Foundation’s volunteer program provided us with an eager and hardworking group of people who passionately protected beaches, and helped band and resight birds. This project can only be done by a team, and it best done by a team of good people who care about the birds. We had that and more.We leave for the Arctic in the last week of June. More on that then.