Rare scrub jay helps regrow oak forests

By Kathleen Wong, UC Natural Reserve System

Thursday, June 9, 2016

Island scrub jays are expanding oak forests, helping to recover natural habitat on Santa Cruz Island.

Birds are known for a variety of things: being ugly as ducklings, nabbing worms when they turn up early, and flocking together with those of a feather. Tree planting, however, is all too infrequently considered an item on the avian docket.

But on California’s largest Channel Island, birds have donned the proverbial planting overalls of Johnny Appleseed.

The bird in question is the island scrub jay. Found exclusively on Santa Cruz Island, the jay is one of the rarest bird species in the United States.

According to ornithologist Mario Pesendorfer, who works out of the Natural Reserve System’s Santa Cruz Island Reserve field station, the foraging habits of this vivid blue corvid are reversing the vegetation damage inflicted by more than a century of sheep and cattle ranching. As a postgraduate researcher with the Cornell Lab of Ornithology, Pesendorfer studies oaks and birds at several NRS reserves, including Hastings Natural History Reservation and Sedgwick Reserve.

Read on and watch video … 

THIS JAY IS EVOLVING IN A VERY, VERY WEIRD WAY

THE SCRUB JAYS of California’s Santa Cruz Island really love a good peanut. “It’s like crack to them,” says Katie Langin, a biologist at Colorado State University who probably knows these birds better than anyone else. Working with Scott Morrison of the Nature Conservancy, Langin started visiting the peaks and valleys of this wild island in 2007, baiting jays with nuts to trap and tag them for her dissertation. Before she came along, what researchers knew about the island scrub jay came from observations in just a handful of places. Much of this rock is inaccessible, but Langin had a helicopter.

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Rare Santa Cruz Island bird may be endangered

The current population of the island scrub jay, a rare California bird, is only a fifth of what experts had previously believed, a new study reveals.

The island scrub jay is a brightly colored blue and gray bird that is only found on Santa Cruz Island, about 17 miles off the coast, south of Santa Barbara.

The study was led by the Smithsonian Institution's Migratory Bird Center in Washington, D.C., and published in the journal Ecological Applications. According to its findings, the island scrub jay is one of the rarest birds in the United States, even though its population has increased in recent years.

"The bad news is that we only have about 2,500 of these birds left, a very small number for any species," says Dr. Scott Sillett, lead author of the study and part of the Smithsonian's Migratory Bird Center. "The good news is that we are seeing an increasing population trend. It appears that there has been about a 20 to 30 percent population increase in the last 25 years owing to a series of conservation actions on the island."

The study says that the island scrub jay has a population size similar to or less than that of other species currently listed as threatened or endangered in the United States. As a result of this study, the International Union for the Conservation of Nature has raised the threat level for the species from "near threatened" to "vulnerable to extinction." However, neither the federal government nor the state of

Continued:  http://www.mercurynews.com/animal-life/ci_22011864/rare-santa-cruz-island-bird-may-be-endangered

Rare bird indeed: Count reveals scrub jay among rarest in US

There are far fewer island scrub jays than previously thought, a new calculation of their population size finds. The new count makes them one of the 10 rarest songbirds in the continental United States.

Previous work overestimated their population by fivefold, according to the new study, published in the October issue of the journal Ecological Applications. This overestimate was caused by incomplete sampling, according to a statement from the Smithsonian Conservation Biology Institute, whose scientists co-authored the study.

The striking blue bird lives exclusively on California's Santa Cruz Island. Despite the reduced population estimate, its numbers have grown slowly in the past few decades thanks to the removal of non-native pigs, sheep and cows that destroy the birds' habitat.

The study estimates that there are 2,500 scrub jays living in the wild. The scientists counted jays at more than 300 locations on the island and used a computer model to fill gaps in their data. Using vegetation maps, they found the birds were most prevalent in areas dominated by scrub oak trees.

As a result of this study, the International Union for Conservation of Nature has changed the island scrub jay's status from near-threatened to the higher-risk category of vulnerable, according to the statement. Threats to the bird's small population include restricted island range, lack of genetic diversity, West Nile virusand loss of habitat to oak disease and wildfire.

http://www.msnbc.msn.com/id/49823936/#.UKTndeRp2Z8