Mercer Corporate Park 11/21--Barnacle Goose

Barnacle Goose 

Theories abound as to why Mercer Corporate Park, which is a small one story building at the back of a circular drive with two retention ponds in front, attracts some many rare birds.  Some think it is its proximity to Assunpink, yet the birds found at Mercer rarely show up at the much larger WMA. Others think that birds using I-195, which runs right next to the park, as navigational guide, see its little ponds as a natural place to plunk down for a rest. Some like the theory of observational bias--since one rare bird was found there, birders go there to look and find other rare birds--sort of the Patagonia Picnic Table Phenomena. Others like me, figure it doesn't take a long time to search, so why not search? So, the more coverage, the more rarities. But that doesn't explain why the "hit" percentage, even for me, is quite high.

So, when I was done with my wanderings in Assunpink today where I found nothing of note, I thought that as long as I was in the neighborhood, I may as well visit the park and see if any rare geese were around. It took less than 2 minutes for me to scan the 175 or so Canada Geese before I found the Barnacle Goose standing among them on the far shore.

The first Barnacle Goose we ever saw in NJ was at this park 6 years ago. We didn't know the area and made the mistake of following Google's directions, ending up in a residential neighborhood. It was only after Shari thought we'd passed a big flock of geese "way back there" that we retraced our steps and found the Barnacle in with a few hundred of the more standard geese.

With Barnacle Goose I now have, for the year, all the rare swans and geese commonly found in NJ in winter--Barnacle is usually the easiest one to find (Cackling Goose is probably more common but also much harder to distinguish and thus overlooked a lot), but it took until late November this year for me to stumble upon one. And it is always more satisfying to find one on your own than to chase the rarity.

Another theory just came in by email: the area use to be a wetlands and it is still part of the migratory route.

One more comes to mind: Magic.