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Plover Hide and Seek

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A snowy plover chick’s cryptic coloring helps it hide from predators. (Photo: Rachel Smith, SDZG at Marine Corps Base Camp Pendleton)

Well it’s finally here, SUMMER! As a born-and-raised San Diegan, I know that one thing is for certain this time of year: the beaches become a popular place to visit for some fun in the sun. Besides having to share the sometimes-crowded beaches with other humans, we need to remember that there are other animals that also live on the beach. I am fortunate to have the opportunity to work with two of those wonderful animals, the threatened western snowy plover and the endangered California least tern.

The snowy plover can be seen year round in San Diego, but the California least tern only comes to our shores during the breeding season, which is April through August. I’m sure if you’ve been anywhere near the tern breeding colonies, you will have seen these small white birds flying around like fighter pilots chasing one another and sounding like storm trooper ray guns. The plovers are small, sandy brown shorebirds with gray legs that hang out in the wrack line of kelp, eating as many bugs as they can get in their bills.

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Can you spot the snowy plover chick hiding in this vegetation? Click on the image to enlarge it. (Photo: Rachel Smith, SDZG at Marine Corps Base Camp Pendleton)

During the summer at Marine Corps Base Camp Pendleton, the beaches are full of plovers and terns nesting and raising their chicks. For both terns and plovers, it takes about four weeks for chicks to be able to fly. Thus, they have to rely on camouflage to evade the eyes of predators; as biologists and monitors, this camouflage can make it challenging for us to locate them. Plover chicks are particularly good at hiding. First off, for lack of a better description, they are adorable. They look like freckled gray cotton balls with legs. Those legs come in handy when evading land predators, especially as the chicks get closer and closer to fledging (meaning they can fly). Their first defense is hiding, especially when they are young, and these little guys are experts at hide and seek.

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There it is! Click on the image for a better look. (Photo: Rachel Smith, SDZG at Marine Corps Base Camp Pendleton)

We are always keeping an eye out for them, looking for clues based on the behavior of the adult plovers (especially adult males) but we don’t always find them. It’s amazing how well the chicks blend into the sand and vegetation. They practically disappear and you often have to be right over them to see them. Often, our best chance of seeing the chicks when we are out monitoring is using our truck as a makeshift blind to watch for them out foraging around in the dunes and along the water’s edge. Amazingly, the birds do not perceive the truck as a threat and we can get much closer when we are inside the truck than outside of it.

Another technique we use is to blend in by staying a long distance away and using a spotting scope or binoculars to watch the behavior of the adult male (who does the rearing of the chicks) to find out where the chicks are hanging out. Watching these chicks grow up to become fledglings is a real treat, especially when I see them trying out their wings and getting a little air for the first time. It just puts a smile on my face knowing they have made it and are pretty much all grown up.

So, while I’m out with my fellow biologists doing our part to help protect these amazing animals, you as beach goers can do your part by respecting closed beach areas even when it is crowded, and keeping the beaches clean not only for each other but for all the animals that live there too. By doing this you can be a hero for wildlife and go home happy knowing that you are giving plovers and terns a safe place to grow up for future generations to enjoy.

Rachel Smith is a senior research associate at the San Diego Zoo Institute for Conservation Research.

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Condor Chick: Getting Big!

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There she grows! Antiki is feathering out nicely.

Antiki, our California condor chick featured on this year’s San Diego Zoo Safari Park’s Condor Cam, is now over 100 days old and starting to get her “big bird” feathers! As many of our regular viewers have noticed, her flight feathers are growing in. Some of the first feathers that start to grow are the wing feathers. It is easy to see the feathers growing through the chick’s down—the down feathers are gray, but the new flight feathers are black. The long feathers that grow from the tip of the wing are called “primary feathers” and the feathers from the wrist to the armpit are “secondary feathers.” Primary and secondary feathers are the giant feathers that make the California condor’s wing so large and impressive; an adult can have a wingspan of up to 9 ½ feet! We are estimating our chick’s wingspan to be around 5 feet right now—between the size of a red-tailed hawk’s and a bald eagle’s. Her tail feathers are also starting to grow. They’re a little harder to see on camera, but you should be able to spot them soon.

After the wing and tail feathers fill in, the feathers on the chick’s back will start to grow, as well as the small feathers on the top of the wing (called “coverts”). Even though many new, black feathers will be covering parts of her body, she will still have lots of gray down showing, making it easy to differentiate her from her parents. Eventually, her light-colored skin will turn dark grey or black and be covered with fine, fuzzy feathers, but this won’t happen until well after she leaves the nest. Her skin will stay dark until she reaches maturity at 6 years and it turns pink-orange, just like her parents’, Sisquoc and Shatash.

The chick had her second health exam on June 25 during which our veterinary staff were able to administer her second, and final, West Nile virus inoculation. A blood sample was obtained and she weighed in at 13 pounds, 7 ounces (6.1 kilograms), over half of her projected adult weight. Even though our little girl is getting big, she still has room to grow!

The adult condors normally are fed four days per week. The other three days of the week, they are fasted. They often will not eat every day in the wild, sometimes fasting for up to two weeks, so our nutritionists recommend not feeding them every day to prevent obesity and food waste. Their diet, depending on the day, can consist of rats, rabbits, trout, beef spleen, or ground meat. We offer two to three pounds of food per bird per feeding day. When the condors are raising a chick, in addition to their normal diet, we offer extra food every day: 1 rat, 1.5 pounds of beef spleen, 1 trout, and half a pound of ground meat. They don’t end up feeding all of this food to the chick, but we want to be sure that they have enough for the growing baby. It’s difficult to calculate exactly how much food the chick is eating each day, but we estimate that she could be eating 1.5-2.5 pounds of food per day.

Many Condor Cam viewers have seen some rough-looking interactions between the chick and her parents. What may have been happening was a form of discipline. As the chick has gotten bigger, her begging displays and efforts have gotten more vigorous. These efforts can sometimes be bothersome or problematic for parents that just want some peace and quiet. The parents have two ways to make sure that the chick does not cause too much trouble while begging. They can leave immediately after providing food, which is what we’ve seen a lot of on Condor Cam; or they can discipline the unruly chick. This discipline can come in the form of the parent sitting or standing on the chick, or the parent may nip or tug at it. Either of these behaviors results in the chick being put in its place by the dominant bird in the nest, thus ending the undesired behavior. Sometimes, this discipline may occur before the chick acts up. Be mindful that this is perfectly normal for condors to do, even though it would be cruel for us to treat our own babies like that! When condors fledge, or leave the nest, they need to know how to interact with dominant birds at a feeding or roost site. This seemingly rough behavior from the parents will benefit the chick later when it encounters a big, unrelated bird that might not be as gentle.

There have been many questions regarding the chick being able to jump up on the nest box barrier. She hasn’t jumped up yet, but she may soon. Stay tuned for our next blog that will discuss this next big milestone!

Ron Webb is a senior keeper at the San Diego Zoo Safari Park. Read his previous blog, Say Hello to Antiki!