Photos from the Field

 

  

 Charles Hofer, a seasonal with the Endangered Species

Program bands some osprey young

 A adult male flies by with a fish

 An osprey nestling stares me down

 

Charles Hofer checks a nest up at Sedge Islands WMA
 

A large ground nest at Sedge Islands

June Platform Install

On June 20, I helped Connor Biggs, a Boy Scout, by sponsoring his Eagle Scout Project where he placed four artificial nest platforms for ospreys near Mantaloking, New Jersey. As a part of the sponsorship I mainly provided guidance on how to build and install the platforms. I also mapped several locations where there was "suitable habitat" for ospreys to nest in the area. Suitable habitat for ospreys is basically any open area that is near water and food; so many coastal areas can have great habitat for ospreys to nest on artificial structures. Northern Barnegat Bay is an important area because it is the largest and most undeveloped northern estuarine area until you reach Sandy Hook along the Atlantic Coast of New Jersey. This has been an area of interest for me. In this area some ospreys are forced to nest on structures that are not exactly suitable. A couple years ago a pair tried nesting on a house in Lavalette. Luckily we were notified early enough in the nesting season and were able to place a platform near "suitable habitat" west of Chadwick Island. The pair was successful that year and is nesting there again this year.

We finished the installation in approximately four hours, which included me shuttling helpers to and from the marsh. If you know anyone who is looking for an Eagle Scout project you can have them contact me. I'd be happy to sponsor other scouts looking for conservation projects in New Jersey.

Jon Rosky looks on as the platform is leveled

Josh Mayo, John Roberts Jr, John Clayton, Jon Rosky, Jimmy Plaganis,
Connor Biggs, Ben Wurst, Kurdy Biggs, Bob Ward, Kiernin Biggs, John Biggs, Loyd Rogers, Austin Rogers
and John Roberts

2009 Aerial Survey is Complete!

On Friday, I got the opportunity to fly along with Kathy Clark, Supervising Zoologist with the Endangered and Nongame Species Program to conduct the final aerial osprey survey for 2009. This was an awesome experience!! In my career, I've only seen osprey platforms and their habitat from either Google Earth or from the ground. This really gives you better understanding of why ospreys nest where they do. Ospreys nests near water and near food. Both of which are plentiful along the bayshore. This survey will help us determine the total number of nesting ospry pairs, statewide and it will also help us determine the productivity rate or rate of reproduction (basically how healthly the population is as compared to previous years). For the survey we flew from Woodbine to Dennis Creek, where our survey began. From Dennis Creek we flew along the Delaware Bayshore to Salem.

 This nest is located along Dennis Creek

We covered a huge amount of land. We were constantly on the lookout for new nests in trees, shacks, duck blinds, or on new platforms. Many of the known nest sites were occupied. We also found several new nests, mostly in snags, or dead trees. Like this nest in a huge dead cedar (below). In all we found 38 active nests along the bayshore.

A nest in a dead cedar tree.

A nest behind houses along Reeds Beach Road.

With the conclusion of this survey we've found that in New Jersey we have 430 nesting pairs of ospreys. Up from 400 nesting pairs in 2006. That puts the population growth rate at about 8% from 2006. In the next few weeks we will be conducting ground surveys to determine the productivity rate (or the overall health of the population). Come back soon for more results and photos!

The First Young of the Year!

Three ~5 day old young lay low in the nest.

On Tuesday, while out in the field along the Delaware Bayshore in Heislerville I stopped to check one osprey nest and observed the first young of the year! I noticed that the pair was no longer incubating from the behavior of the adults, so i decided to stop and check. When they have young they are not seen "sitting tight" or incubating any longer, this is usually an indication that they have young. This was the case on Wednesday. When I approached the nest with the boat, the adults left the platform and began calling in a defensive way to try and deter me (as they see me and any other human as a predator) from reaching the nest. The defensive calls warn other adults in the area and signal the young to lay down or "play dead" as you can see in the photo. The young "play dead" up until they are around 6 weeks old. After 6 weeks they are much larger and more closely resemble an adult and are more likely to stand up and defend themselves (see picture below).

The good news is that this nest is active this year and has 3 young! It was not active in 2008.

A 6 week old nestling exhibiting defensive behavior.

Weather can directly impact productivity

In late May and early June, many eggs begin to hatch. Osprey hatchlings are considered semi-altricial at birth or are covered in down, blind and need close parental care (feeding and body warmth). For approximately the first 7-10 days the young are very vulnerable to extremes in weather conditions, especially cold and damp conditions. This spring has definitely been a cold and wet one. This week I have been constantly thinking of our osprey parents, closely brooding their eggs and young to keep warm. I hope this rain ends soon, and I also hope that it does not have too much of a negative impact on our population this year!

In 2003, productivity was below normal. Mainly caused by adverse weather conditions. It was a cold wet spring. In the 2003 Osprey Newsletter, Kathy Clark wrote:

"The most likely cause of this year’s nest failures is the weather during April and May, when ospreys were incubating and just hatching. It was unusually cool and wet, and those conditions can have several implications for ospreys: the high precipitation may have delayed fish migration and spawning, making prey harder to find; it may also have increased water turbidity, making it more difficult for ospreys to see fish. As ospreys spent more time hunting with less success, their
incubating partners may have been forced to leave the nest – exposing eggs or young chicks to
weather and predators – to hunt for themselves. In addition, we found that many young nestlings
died when they were just two to three weeks old in June and early July, most from starvation, so the
effects of the cool spring were far-reaching. Unlike previous years when nest success declined in one
region or another (primarily the Atlantic Coast), this year’s problems were statewide, which supports
the theory that weather was the predominant cause."

In approximately 2-3 weeks we will begin our annual ground survey where we collect data to help calculate the productivity rate and band young for future tracking. With this data we can determine the success of the breeding season.

Coming Soon!

This week I'm finally going to edit and produce Part 2 of my osprey platform construction and installation videos on YouTube. This video will focus on installation of a platform. Stay tuned!!!!

Oh, if you have yet to see my other videos on YouTube, scroll down to the bottom of the blog!