Bluebird Business as Usual

It's a project that I'm all too familiar with. It was one of the first projects I got to help with when I first interned here last summer. And in terms of what to expect every time, this project falls into 1st place for being the most variable.

If you've been around the museum or Ongley Pond, you've most likely seen some of our bluebird boxes. The boxes are set up in a way to be both easily accessible to people and inaccessible to predators. These boxes are checked periodically at 2-3 week intervals. The interns and I go out to the boxes with a cordless drill and proceed to open them up one at a time. Our task is to then check the nest and write down all relevant data. This data includes bird species type, number of eggs/young, young status, and nest status.
White Memorial has been taking part in this statewide program since the 1990's. Coordinated by the Connecticut DEEP, the objective of the program is to restore the Bluebird populations that have been in decline for over 40 years. Species like the Bluebird and Tree Swallow are cavity-nesting songbirds that require preexisting cavities in their habitat in order to nest. By providing said habitats, we are able to give the birds safe areas to raise their young and thus help to bring their population back up. Besides this, we are able to use the nest box data for other purposes. For example, we can use the data to keep track of these bird populations throughout the season. We can see where each species type is hanging out and who's using which boxes. We can also get an idea of how many nestlings are surviving to adulthood.

House Wren nestlings in one of our boxes

Thankfully this project is one that interns can easily pick up on. It does take time to go to each box and record all relevant data. Though it isn't a particularly grueling task, the job isn't always a walk in the park. An outsider watching us work would probably find a couple reasons to laugh at us. The birds (especially Tree Swallows) are quite territorial around their young, meaning that they don't appreciate it when we come out to visit them. This means that we end up getting dive-bombed by birds on a regular basis. Don't worry. We get used to it. 

Songbird Nest Box Program Seeks Volunteer Monitors

Songbird Nest Box Volunteer training will occur on Saturday, March 23, 2013, 10:00 a.m. to 2:00 p.m. in the A. B. Ceder Classroom.  Please bring a lunch, paper, and pencil. Dress for the weather.!

Eastern Bluebird
Photo By Bob Stanowski

All wildlife populations are regulated by many things in their habitat. One factor that limits cavity nesting songbirds is the availability of appropriate nest sites. Certain species like woodpeckers create their own nest site by excavating wood with their chisel-like beaks. However, there are several cavity nesting birds that do not create their own cavities but use ones that are already present in their habitat. Eastern Bluebirds and Tree Swallows are a couple species that require pre-existing cavities before they can reproduce. Eastern Bluebirds experienced severe declines in Connecticut starting over 40 years ago. This was due in large part to ecological changes that succeeded open fields to forests and due to a lack of nest sites. A statewide program was coordinated by CT DEEP, Wildlife Division to restore Eastern Bluebird populations by installing nest boxes throughout the state. White Memorial has been part of this initiative since it’s inception by installing nest boxes throughout the property since approximately 1989. Since then the Bluebird population has responded to this conservation strategy quite well by steadily increasing in abundance (Figure 1). This year starts a new phase of White Memorial’s Songbird Nest Box Program. Volunteers are needed to monitor 75 nest boxes for success and productivity.

Figure 1:  Eastern Bluebirds Counted on USGS Breeding Bird Survey Routes 

that Traverse WMF (1967 - 2008), Trend-line Added.

Figure 2:  Eastern Bluebird Summer Distribution Map  from USGS Breeding Bird Survey (2006 - 2010).  Sauer, J. R., J. E. Hines, J. E. Fallon, K. L. Pardieck, D. J. Ziolkowski, Jr., and W. A. Link. 2011. The North American Breeding Bird Survey, Results and Analysis 1966 - 2010. Version 12.07.2011 USGS Patuxent Wildlife Research Center, Laurel, MD.

The Songbird Nest Box Program has proven a success for helping to restore Eastern Bluebirds to WMF but it only helps the birds a little. Eastern Bluebirds are not consistently successful at fledging young every year. Connecticut is found in the more northern portion of Eastern Bluebird distribution and southern populations are more abundant than northern populations (Figure 2). This suggests that Eastern Bluebirds are better adapted to a slightly warmer climate. Yet, Connecticut offers enough habitats to make it worth a Bluebird’s effort to still attempt to reproduce because some birds are successful at producing young even though some seasons do not offer the best conditions.  Bluebirds migrate as early as they can from winter habitats (April) so that they can locate a nest site, reproduce, incubate eggs, and raise young. This gives the young enough time to develop so they are physically capable of migrating to warmer climates by the next winter. Connecticut’s breeding Bluebird population is vulnerable to early spring weather conditions that could kill young birds due to exposure. Late frosts, extended cold rain, and freezing temperatures contribute to young birds dying. The nest boxes are designed to meet the needs of the birds while they need a nest site by providing as dry a micro-habitat as possible and protecting the birds from predators and non-native species.  The habitat around each nest box is managed by mowing and controlling the vegetation so that Bluebirds can find enough food for their chicks.  Check the map at the bottom of this page to see the Songbird Nest Box locations.  The boxes must be visited to collect data and to assess how the box is functioning. We have designed a program that provides the volunteers with the option of deciding how much time they can commit to the program. Each nest box must be visited at least twice a year but more frequent visits allow us to learn more about the population. If you have only a little bit of time then you can meet the minimum requirements, but if you have more time to commit then the program will benefit. There are several important things to learn about nest boxes and the birds that use them prior to volunteering with the program. Therefore, we require that if someone wishes to volunteer their time, they must attend a training session offered by WMCC Staff.

It's Time to Get the Songbird Nest Boxes Ready!

It's time to check those nest boxes to insure they are ready for this breeding season.  We'll be hosting a volunteer training for those people who would like to help us with monitoring all of the nest boxes on the property.  More information about the workshop will be posted soon, but take a look a the video in the meantime to see who makes them and how they are created.

Results of 2012 Bluebird Box Usage

Tree Swallow perched on Bluebird box

Female Bluebird
Photo by Bob Stanowski












In the beginning of August all Bluebird boxes on White Memorial property were opened, inspected, and cleaned out. Unfortunately Bluebirds had a difficult breeding season, resulting in a 41% success rate. Weather was mostly to blame for this low percentage. Bluebirds start to lay their eggs in mid-April; and as some recall in the beginning of May this year we had lots of rain with unseasonably cold weather. This combination of cold air with damp conditions proved to be too overwhelming for the eggs and chicks; this became evident when we discovered many dead chicks and abandoned eggs. However Tree Swallows, who also use the boxes for nesting, had a positive season, with an 81% success rate, occupying most of the boxes. There were also twelve House Wren nests, half of which were constructed on top of Bluebird or Tree Swallow nests. Male House Wrens are aggressive and will destroy the eggs and young of other birds in order to use the nesting area. House Sparrows will also evict any nesting bird to take over the site, although only three House Sparrow nests were found in the boxes. House Sparrows are less tolerated around Bluebird boxes than House Wrens because House Sparrows are invasive species. First released in Brooklyn in 1851 from Europe, House Sparrows have become one of the most abundant and widespread songbirds in North America. Other unwelcome wildlife includes paper wasps found in five boxes and a White-footed Mouse in one box. In conclusion, 72 out of the 76 Bluebird boxes were active; meaning that a bird at least attempted to build a nest there, and of these 72, 70 were actually used to raise chicks.     

House Wren nest with six chicks inside stacked on top of a Bluebird nest

Summary of Bluebird Nest Box Usage at White Memorial in 2011

Eastern Bluebird photo by Bob Stanowski

Eastern Bluebird Used Nest that Successfully

Fledged 3 Young from a Nest Box in

White Memorial's Mill Field

photo by Dave Rosgen

Tree Swallow photo by Darlene Knox

House Wren photo by Ann Cook

from www.learner.org

The 2011 nesting season was a record-breaking success for Eastern Bluebirds, but a near disaster for Tree Swallows using CT. Bluebird Restoration Project nest boxes on White Memorial Foundation land. Weather was a major player in these results. While Bluebirds either timed their nesting activity right or just got lucky, they managed to avoid the worst of the awful cold, wet weather that plagued Northwest Connecticut for parts of May and June. Many of White Memorial's Bluebirds made their first nesting attempt and successfully fledged young during a nice stretch of weather in May, then delayed making their second nesting attempt until nice weather returned in July. One pair even nested successfully 3 times this year!

Connecticut Bluebird Restoration Project

Summary of bluebird box usage at: The White Memorial Foundation

Towns: Litchfield & Morris

Year: 2011 Number of boxes: 82

SPECIES	# of Pairs	# of Active Nests	# (%) Successful	# Failed	# of Young Fledged	# Fledged per Active Nest
Eastern Bluebird	19	25	23 (92%)	2	91	3.6
Tree Swallow	50	51	39 (76%)	12	170	3.3
House Wren	5	6	6 (100%)	0	20	3.3
Black-cap Chickadee	2	1	1 (100%)	0	5	5.0
Tufted Titmouse	0	-	-	-	-	-
White-br Nuthatch	0	-	-	-	-	-
TOTALS	76	83	69 (83%)	14	286	3.4

Unwelcome Nest Box Tenants

SPECIES	# of Boxes Occupied	# of Nests Removed	# of Successful Nests	# of Young Fledged
House Sparrow	6	5	3	7
White-footed/ Deer Mice	3	3	-	-
Paper Wasp	6	12	-	-
Dominion Wasp	-	-	-	-
Ants	4	8	-	-
TOTALS	19	28	3	7

A record-high total of 19 pairs of Bluebirds used our nest boxes this year. Of their total of 25 active nests, 23 were successful in fledging a record-high total of 91 young. That made for an excellent success rate of 92% and productivity rate of 3.6 young fledged per active nest. They only suffered 2 nest failures: 1 due to a House Wren destroying a clutch of eggs and the other due to a huge Raccoon eating a clutch of eggs. More on him later. Tree Swallows started their nesting activity slowly in April and May and plugged along trying to nest and bring-off a brood of young through June's horrible weather. Many of them met with failure. Actually, some of our 50 pairs of Tree Swallows suffered from more causes of failures than just the weather this year. A huge Raccoon somehow found a way to climb up the otherwise Raccoon-proof PVC pipe predator guards on 4 nest box poles and get the eggs in the boxes. Non-native House Sparrows caused 2 of the Tree Swallow failures, and a House Wren caused 1 failure. Otherwise, 5 of their record-high 12 failures were caused by the foul weather. Despite this, they still managed to fledge 170 young from 39 successful nests. This gave them a nesting success rate of 76% and a productivity rate of 3.3 young fledged per active nest. House Wrens don't use many of Bluebird boxes because we try to keep them out in the fields, away from edge habitat that Wrens prefer. Still, 5 pairs of House Wrens did nest in them this year. They were 100% successful in their 6 nesting attempts, and fledged a total of 20 young. Two pairs of Black-capped Chickadees attempted to nest in our Bluebird boxes. One didn't get beyond the nest building stage before a Tree Swallow usurped the box. The other pair was successful in fledging 5 young. The overall figures were good, despite the Tree Swallow's contribution of failures. A total of 76 pairs of native birds made a total of 83 active nesting attempts in the nest boxes. Of these, 69 were successful and 14 were failures. They fledged a total of 286 young. That gave them a combined success rate of 83% and productivity rate of 3.4 young fledged per active nest. As for the unwelcome nest box tenants, House Sparrows tried to nest in 6 of the boxes. Despite removing a total of 5 nests, they still managed to fledge a total of 7 young from 3 late nests that slipped past us. Other problem critters included Mice in 3 boxes, Paper Wasps in 6 boxes, and Ants in 4 boxes.

Wildlife Management and Inventorying Activities, 4/14/11

Red-tailed Hawk photo by Leo Kulinski, Jr.

from whalesandwolves.com Sharp-shinned Hawk photo by Darlene Knox Eastern Bluebird photo by Bob Stanowski

Bluebird nest box photo by Dave Rosgen

Yesterday, 4/14/11, Volunteers John Eykelhoff, Jim Kandefer, and Bob Stanowski assisted me with bluebird nest box maintenance and monitoring and a wide variety of wildlife surveying. Most of the time this type of field work is a case of multi-tasking. While working on the bluebird boxes we frequently scanned the skies for raptors, looked around the fields and edges for other birds and mammals, and listened for any birds or frogs than might be calling. Since it was a nice, sunny, warm day there was a constant concert of bird and frog sounds to enjoy. This included our first Northern Leopard Frogs of the season at the Litchfield Town Beach and in the Icehouse Marsh. Our first Common Snapping Turtles of the year also appeared today. Gerri Griswold and Lee Cook saw a huge one moving very slowly in the Bantam River and I saw a big one sticking its head out of Bantam Lake's N. Bay. Our third first-of-the-year animal found this day was a Blue-gray Gnatcatcher behind the Campground Store. Hawk migration activity was very good, with the best viewing being from the Bantam River Field. While replacing a rotted wooden bluebird box pole with a new metal one and replacing a cracked bluebird box front door we saw 3 Ospreys, a Sharp-shinned Hawk, and a Broad-winged Hawk fly over. Turkey Vultures and the resident pair of Red-tailed Hawks were also circling around overhead. These, and 3 other pairs of Red-tails seen elsewhere this day, were engaged in courtship activity. Migrant songbirds seen included Palm and Yellow-rumped Warblers. Eastern Bluebirds were seen at 4 nest box locations, and one of the boxes had a complete nest in it already. Tree Swallows were abundant everywhere. They were joined by a Barn Swallow in the Icehouse Field and N. Rough-winged Swallows at Wheeler Hill, the Bantam R. Field, and Cemetery Pond. Bantam Lake produced lots of action. This included at least 5 Ospreys fishing. Three of them were successful while we watched them, but one promptly lost its catch of a Northern Pike when an adult female Bald Eagle chased and scared it. The Pike disappeared when it hit the water, and the eagle failed to retrieve it. In addition to this eagle, an adult male (possibly her mate) was perched in a White Pine on the east shore, a 3rd-year immature female was flying around and then perched in a tree in N. Shore Marsh, and a 2nd-year immature male was perched in a White Pine at the tip of Lennox Hill Pt. He was being mobbed by American Crows for awhile. Bob was able to get really good Digiscoped photos of these eagles, so I will use them to do a future blog about the ways to determine the ages of immature and subadult Bald Eagles. While the eagles posed for photos, an immature Northern Harrier flew past us and disappeared into N. Shore Marsh, 7 Rusty and many Red-winged Blackbirds called from trees in the Marsh, 2 Green-winged Teal and 3 Wood Ducks swam along the shoreline, and 21 Double-crested Cormorants lazed on the stone blocks in N. Bay. Finally, we ended the day with 3 American Woodcock calling and displaying at dusk at Cemetery Pond. If you take a trip out to these locations, especially in the late afternoon and evening, you may very well be rewarded with these same sights and sounds of nature.

The Migrants Continue to Pour in to Litchfield

Yellow-bellied Sapsucker photo by

Lloyd Spitalnik via Google Images Savannah Sparrow photo from friendsofsherwoodisland.org via Google Images Brown Thrasher photo from friendsofsherwoodisland.org

via Google Images

Migrant birds have continued to pour into and through Litchfield County for the past few days. My previous blog post covered the first waves, and this post will talk about the next waves that have arrived. The earlier migrants were mostly waterfowl and other birds associated with water. They began to appear even before much ice had melted on Bantam Lake and our ponds. Now that the ice is all gone from them, even more birds in this category are moving through. A lot of them are fish-eaters. Common Mergansers have been here for over a month, but now they number around 400 at Bantam Lake. They have been joined by 4 Red-breasted Mergansers, which are very uncommon at inland bodies of water. Common Loons normally migrate through Connecticut in April, with one or two being seen daily at Bantam Lake. Imagine Mike Doyle's surprise last Wednesday, 4/6, when he counted a whopping 44 at the Lake. This could be a record high number for any inland body of water in this state. The next day, 23 were still there. Their numbers have dropped slowly since then to 9 as of yesterday as more of them continue their migration northward. During this same time span Double-crested Cormorants have appeared and increased in number to 20 as of 4/8. The fish-eaters have also included 2 Horned Grebes and a Red-necked Grebe (which is rare here) in the central section of the Lake on the 7th. Hunting from above have been many Bald Eagles and Ospreys. On the shore, the number of Great Blue Herons continues to increase daily, and an American Bittern appeared at the Litchfield Town Beach on the 7th. A Bonaparte's Gull was a rare find at the Lake's N. Bay on the 8th. Gull numbers, in general, are suddenly way up at the Lake.

Terrestrial birds have also been on the move. Swallows, especially, have seen a big increase in number in the past couple of days. We counted approximately 200 Tree Swallows at Bantam Lake on the 7th and about 100 at Little Pond yesterday. This latter count also included a Northern Rough-winged Swallow and a Barn Swallow. In the trees, Yellow-bellied Sapsuckers have surged in numbers since 4/7. On the ground, sparrow numbers and diversity have increased substantially lately. Fox Sparrows have been numerous at the Museum's feeders for a month, with 7 being counted there on 4/8. Savannah Sparrows have been seen at the Sutton's Bridge section of the Little Pond Boardwalk for the past 3 days, and one was seen a couple of hours ago on the west lawn of the Museum. Chipping Sparrows have been around the Museum for about 5 days. Song Sparrows have become quite numerous. Dark-eyed Juncos are everywhere! Best of all, a Brown Thrasher appeared in the Activity Field this morning. It sang from the tops of the Hawthorns for quite a while. This species has become very rare in Litchfield County, so it was a real treat to see it.

Bluebird Nest Box Spring Inspections

Adult male Tree Swallow photo by

Bob Stanowski

Adult female Eastern Bluebird photo by

Bob Stanowski

Photo by Dave Rosgen of WMCC volunteer

Jim Kandefer opening a bluebird nest box

for inspection in the Bantam R. Field

The Connecticut Bluebird Restoration Project currently maintains 78 bluebird nest boxes on White Memorial Foundation property in Litchfield and Morris. We monitor them regularly from mid-March through mid-October, with the first and last inspections of each year focusing on addressing maintenance needs and performing vegetation management. Fortunately for us and the birds, most of the nest boxes are less than 5 years old, and, thus, don't require much maintenance work. Just like anything else, as the boxes age, they require more maintenance. Eventually, it gets to a point where it is no longer practical to continue repairing an old box, and it is replaced with a new one. This usually happens when a box is between 12 and 15 years old. We are able to achieve such long life spans by using high quality white pine lumber for all of the component parts of the nest boxes, fastening the parts together with 1 5/8" drywall or deck screws (never nails!), and by caulking the seams between the back and sides and top and sides. This technique has proven to be very effective in keeping moisture out of the boxes, which, in turns, keeps them from rotting prematurely. All of the poles are fitted with hardware cloth or aluminum flashing mouse guards as a cap over the PVC pipe predator guard (which is essential!) that encircles the pole on which the box is mounted. Mice can ruin a nest box in one season, so it is extremely important to keep them out. Ice and snow can take more of a toll on nest boxes than rain, so it is really important to check them in March in order to repair winter-caused damage. So far this spring we've been lucky. Out of 24 boxes inspected in the past week, only 2 needed to have component parts replaced. In both cases, the front door was split; probably from moisture entering cracks and then freezing. We also found one old wooden pole to be rotted. That will be replaced very soon with a new metal pole. Over the past few years we've been transitioning away from wooden poles to metal ones because the metal ones last so much longer. We also found one pole at a 45 degree angle, and straightened it back up. This might have been caused by a buck White-tailed Deer sparring with it last fall. While checking the boxes we were pleased to see a pair of Eastern Bluebirds back on territory in each of the fields, and a group of 8 newly-arrived Tree Swallows in the Alain White Rd. field. These maintenance inspections will probably continue for another 2 weeks, until all of the boxes have been visited, and until any problems that are encountered are corrected.