The birds fatten up on the eggs and then make the four thousand mile journey north. Come late to dinner and you don't make the trip. It's non stop and if you have not eaten enough to give the necessary energy, you die in route. But the birds you see here are not migratory. They are greedy home based seagulls that also partake of the egg feast. There are like pigeons in the cities.
We didn't see any Red Knots. We did see bodies of the crabs strung across the beaches. They are at the top of the beach line. We spent one evening at one of the access areas to the beach where the crabs were being tagged by volunteers. We were there late into the evening and the crabs began to come ashore around dark and when the birds had gone away. How many came ashore in the thirty foot section we were allowed on, the rest of the beach area is off limits this time of year, we can't tell because of dusk closing in fast. But we were told by the taggers that they had tagged 700 of them two days before and the only reason they stopped was because they ran out of tags. We were also told that just two nights prior, at another access point, you couldn't walk in the area because there were so many Horseshoe crabs.
This is the remains of a crab that didn't make it back with the tide. On it's back with no way to turn over without the help of the tide or people it becomes an open platter for the birds.
In the background there is another left over of the tides as the birds feed on the eggs of the crabs. But that's nature. The Horseshoe lays so many eggs there is more than enough to maintain their existence. That is until man came along and decided to harvest the crab for bate and other purposes. As the numbers of crabs diminished through over fishing it adversely affected other species. My understanding is the eyes of the crab are similar to human eyes and research has be ongoing with that for decades. As a human food source there is not enough edible on it to make it a good food source. Luckily horseshoe.
As the Horseshoes came ashore that evening into night I tried to capture some photos of the tagging. The lighting was so poor that I could not get a good focus nor good pictures even though I was using the camera flash. But the method is to drill a small hole in the shell of the crab and attach a disc tag to the hole that does not come off in the water. The disk is about an inch and a half in diameter. The hole drilled into the shell of the crab is minor and just enough to insert the nipple of the disk. After tagging they the are registered and returned to the sea. One tagger said she recovered a Horseshoe that had been tagged four years ago. It only added to the mystery of where do they go when this mating season is over. They still don't know.
So what is the purpose of the Horseshoe Crab? To produce bird food.
