Friday, January 5, 2018

10 Avian Mysteries at Pheasant Branch Conservancy



Once a regular and common nester from 2007 to 2013 (post initial habitat restoration efforts), this photograph shows the very last Clay-colored Sparrow (Spizella pallida) observed and photographed at Pheasant Branch Conservancy's prairie during June 2013 (breeding season). There have been no documented Clay-colored Sparrows during the breeding season since. Meanwhile, there's a healthy population of CCSPs at nearby Pope Farm Conservancy.



The Dickcissel (Spiza americana) is another grassland bird species declining at Pheasant Branch Conservancy's prairie. Though they can be somewhat irruptive and sporadic by nature, their population increased at the prairie from 2006 to 2013. Then there was an abrupt drop in numbers during the breeding seasons of 2014 and 2015, and have since almost disappeared―just one bird on June 26th, 2016, and only 2 observed the following year on June 14th. In the same time frame, they were quite abundant elsewhere in Dane County and throughout southern Wisconsin.



The Eastern Meadowlark (Sturnella magna) has experienced one of the worst population declines in our country's history. In the past 40 years they dropped from over 25 million individuals to around 6 million today. Sadly, this recognizable grassland bird has been declining at Pheasant Branch Conservancy the past several years. Incidentally, one of the most abundant populations of this species in our area can be found at the fields of Middleton Municipal Airport.



Though never common at Pheasant Branch Conservancy, here are my eBird dates for single (mostly) or double sightings of Grasshopper Sparrow (Ammodramus savannarum):

2013-07-13 
2013-07-11 
2013-06-28 
2012-05-31 
2012-05-21 
2011-06-21 
2011-06-05 
2008-07-19 
2007-05-25 

The above photograph was taken in 2004. I'm fairly certain I encountered them at the conservancy in 2005 and 2006 prior to using eBird to document my avian observations. Though there is suitable habitat for this grassland species at Pheasant Branch's prairie, I have not observed them there since the summer of 2013. One of the highest concentrations of these species I know of can be found at Spring Green Preserve in Sauk County.



I still fondly recall the very first Yellow-breasted Chat (Icteria virens) I encountered at Pheasant Branch Conservancy. It was early June 2007. While talking with another birder, I suddenly heard the chat's funky song call out from the south slope of the hill. I was positively thrilled. Though there were sporadic sightings from 2008 to 2011, this secretive and sensitive-to-disturbance species became regular nesters for the next 3 years, and then poof ― gone! This amazingly-cool near-ground nester was last observed at the prairie on July 13th, 2014.



This one kind of surprised me. Though still quite common near wetland areas at the conservancy, the Willow Flycatcher (Empidonax traillii) has experienced slight declines at the Dane County Unit of Pheasant Branch Conservancy the past few years. Nests close to the ground in low shrubs and bushes.



This is the only Sora (Tetsuya Nomura) I've photographed at the prairie parcel of Pheasant Branch Conservancy. I found a dead one along the main gravel path several years ago, but cause of death couldn't be determined with certainty. I have heard them calling just south of the big springs during spring and early summer. It's possible they may be nesting around the retention ponds where this one was photographed.



Never common at Pheasant Branch Conservancy, it seems like the Vesper Sparrow (Pooecetes gramineusshould present and around the oak savanna adjacent to the agricultural field, just like they are at Pope Farm Conservancy. They are quite common at the latter throughout early spring and most of summer.

2014-06-27 1 Mike McDowell Checklist
2014-06-17 1 Mike McDowell Checklist
2011-06-21 1 Mike McDowell Checklist



A somewhat puzzling and mysterious sedge and grassland nesting species, eBird records show steady declines of Sedge Wrens (Cistothorus platensis) at the prairie during the breeding season. Over 100 individuals counted during the summer breeding season of 2013, 35 in 2014, 45 in 2015, 13 in 2016, and only 8 in 2017.



Still fairly common at Pheasant Branch, and possessing one of the most recognizable summer songs, the Field Sparrow (Spizella pusilla) is beginning to show signs of decline around the oak savanna. They primarily nest close to the ground just below the line of oaks on the western and southern slopes of the hill.

All images © 2018 Mike McDowell