Least Tern Nests Washed Away

There is smooth sand and washed out nests and shelters where a thriving nesting colony of endangered Least Terns existed just a week ago along the shifting sands of the Tiuana National Estuarine Research Reserve. The water is gone, but the smooth sand is a sure sign that that the ocean washed up and over the entire nesting area. The terns were gone, parents and all. There will be no second try. Where just two weeks ago, there were a whole string of least tern nests being aggressively guarded from predating seagulls, now there is just sand. Smooth, water washed sand.

I had been timing my return, hoping to see lots of least tern chicks, the eggs having been in the nests for about 2-3 weeks. They should have hatched in the last week. In three more weeks, the fledgling terns would have been able to fly.

It is truly sad seeing a whole generation of terns wiped out, even if by natural causes. In a discussion after the fact, I asked a conservationist staffer on the beach when it happened. She noted that there was a particularly high tide a few days ago which was probably the culprit. She also noted that they are not set up or funded to rescue the eggs from the tides into the safety of incubators. There was simply nothing they could do. Thus, those weeks of erecting protective signs to keep people and pets out from the nesting area, of carefully labelling each nest with popsicle sticks and of building little wood shelters to protect the chicks from marauding gulls ultimately were for naught.

It is tempting to point to global warming and increasingly fickle, tempermental weather and tides or to all those condominiums on the beach that have relegated the least terns to the shifting, somewhat polluted sands of the Tijuana Estuary, a last bastion that developers simply do not want to build upon. Perhaps, it is just nature giving and taking away as it has always done. There is, I suppose, always next year.

Snowy Plovers Benefit From Nearby Least Tern Nests

Juvenile Snowy Plover, Charadrius alexandrinus nivosus, possibly part of this years chicks.  Apparently, more snowy plovers hatch and survive when the snowy plover nests are near least tern nests, due to the active protection of the nesting area by the least terns.  The terns will swoop/dive at and defecate on predators, dissuading at least some of the predation.  Snowy plovers are threatened due to habitat loss.

California Least Tern, Sternula antillarum var brownii

California Least Tern, Sternula antillarum variety brownii, is the smallest tern found in San Diego, at about 22 cm in length.  These tiny little birds glide on the coastal breezes, seeming to hover until they dive at great speed into the shallow waters along the shoreline or in river estuaries to snatch minows and other small fish from the surface.  These lovely birds are under habitat pressure in their native Southern California, San Francisco Bay and Northwestern Mexico, where much of the beach has been utilized for human developments.  The California Least Tern (variety brownii) was listed as an endangered species in 1972 with only 600 pairs in existence.  That population has since rebounded to around 4,500 pairs.  This one here is nesting in a little patch in the sand at the Tijuana River National Estuarine Research Reserve in Imperial Beach, California.  They appear to have recently laid eggs.  This particular nesting area is subject to floods, high tides and shifting sands, resulting in varying levels of nesting success from year to year.  From the looks of it, this year is turning out to be a pretty solid year.