Sunday, August 7, 2016

Saving the Western Snowy Plover

Wildlife conservation is not just something happening overseas.  We hear about elephants, rhinos, sharks and other animals that are in dire need of our help in order to survive in this world and it is crucial that we do all we can.

It is however also needed right in our own back yards and it is just as important to me to get involved one way or another, whether that is through volunteer work or my photography. One organization I have come to know is Point Blue Conservation Science, based in Petaluma, California and avian ecologist, Carleton Eyster whose expertise and efforts for the past 20 years or so,  lie in saving the western snowy plover.

Carleton Eyster with Point Blue Conservation Science
Carleton Eyster monitors Snowy Plover population at Pajaro Dunes, CA

The western snowy plover (Charadrius alexandrinus nivosusi) is a small federally threatened shorebird approximately the size of a sparrow.  During the breeding season, March through September, plovers can be found nesting along shores, peninsulas, offshore islands, bays, estuaries and rivers along the pacific coast.  Their nests are very difficult to spot as you can see in the above image, which is good as far as camouflage, but also makes them easily over looked and potentially stepped on or disturbed.

I recently had the opportunity to accompany Carleton on a visit to Pajaro Dunes to check on the nesting population and watch him band a day old chick.  The process of banding the chicks which are only about 1" in length requires very steady, skillful hands.  Four color coded bands are carefully put around their legs, with each combination of colors unique to the bird.  Sometimes color combinations are recycled if the previous wearer is considered dead. These are then heat sealed, in addition to being taped in matching colors for strength and color fastness.  Plover legs don't grow appreciatively in diameter, so adult bands can be put on the chicks. These bands can last the life of the bird which can be up to ten years.

Their nests consist of a shallow scrape or depression and usually contain three eggs.  These are camouflaged to look like sand and are barely visible, even to the most well-trained eye.  Plovers will use almost anything they can find on the beach to make their nests, including kelp, driftwood, shells, rocks or even in human footprints.  Both sexes incubate the eggs, with the female tending to incubate during the day and the male at night.

Snowy Plover Chick & Egg 
The first chick hatched remains in or near the nest until the other eggs, or at least the second egg has hatched.  The adult plover, while incubating the eggs, also broods the first chick. The non-incubating adult may also brood the first-born chick a short distance from the nest.

If the third egg of a clutch is 24-48 hours behind the others in hatching, it may be deserted.  Plover chicks are "precocial" leaving the nest within hours of hatching in search of food.  They are not able to fly for approximately 4 week; fledging requires 28 - 33 days.

Broods rarely remain in the nesting area until fledging and may travel along the beach as far as 4 miles from their natal area. Adult plovers do not feed their chicks, but lead them to suitable foraging areas.  Plovers are primarily visual foragers, using the run-stop-peck method of feeding.  They forage on invertebrates in the wet sand and amongst surf-cast kelp within the intertidal zone, in dry, sandy areas above the high tide, on salt pans and along the edges of salt marshes, salt ponds and lagoons.

They have natural predators such as falcons, owls, raccoons and coyotes.  There are also predators that humans have introduced whose populations they have helped increase, including crows and ravens, red fox and domestic dogs.  Humans can be thought of as predators too, because people drive vehicles, ride bikes, fly kits and bring their dogs to beaches where the western snowy plover both lives and breeds.  All of these activities can frighten or harm plovers during their breeding season.

Carleton Eyster banding plover chick
Carlton Eyster banding Snowy Plover chick
Energy is very important to this small bird.  Every time humans, dogs, or other predators cause the birds to take flight or run away, they look precious energy that is needed to maintain their nests.

Adults use distraction displays to lure predators and people away from chicks.  They will signal the chicks to crouch with calls as another way to protect them.  They may also lead chicks, especially larger ones away from predators.  More frequently however, when a plover parent is disturbed, it will abandon its nest, which increases the chance of a predator finding the eggs, sand blowing over and covering the nest, or the eggs getting cold.  This can decrease the number of chicks that hatch in a particular year.  Even a kite flying overhead looks like a predator to a plover and if flown over a nesting area, can keep an adult off the nest for long periods of time.

Most chick mortality occurs within 6 days after hatching. Females generally leave their mates and broods by the sixth day and thereafter the chicks are typically accompanied only by the male.  While males rear broods, females obtain new mates an initiate new nests and the cycle begins again.  The more chicks they have, the higher the odds of survival into adulthood.

There are many key things WE can do to help save the plover from extinction.  Allowing these small, beautiful birds to remain in their breeding areas undisturbed throughout the breeding season is most important.  There is plenty of space for people to recreate on beaches AND leave room for the plovers to nest.  The idea is to "Share the Shore", meaning having fun while also protecting our natural environment at the same time.  Simply paying attention to signage and NOT going beyond roped off areas on pacific coast beaches can make a BIG difference in their survival.  Plovers can be very difficult to spot since they nestle in small indentations in the sand, so it is very easy to "stumble" on them without realizing they area right at your feet.

Roped off area with signage at Pajaro Dunes, CA

We are privileged to be able to be stewards of the beach, its habitat and its occupants, including the western snowy plover, so let's protect our beaches and the plants and animals that use them.  Social media has become and amazing way to get the work out about important issues, so please share this story with your friends and family.  Remember...when a species goes extinct, it is gone forever!

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