State College Bird Club Zoom Meeting
March 23, 2022


Presiding: Doug Wentzel

Recording: Peggy Wagoner Saporito

Attendance: 35

Meeting Format: Zoom (due to Covid)

Treasurer’s report:(Jean Miller): Deposited: $185 from dues and hats. Expenses: $50 for speaker and $252 for second order of hats.

Bird Club Field Trips: (Susan Smith)

This month’s field trip is coming up on Saturday March 26. Joe Gyekis will lead us on the downtown State College Tree Walk. Details for all of this spring’s SCBC field trips can be found on our website.

Other Activities:

Weekly Bird Walks at Millbrook Marsh Nature Center continue each Tuesday (8-9:30AM) through April 26. Joe Gyekis, Julia Plummer and Susan Smith are each leading walks. See website: https://www.crpr.org/millbrook-marsh-nature-center
Shaver’s Creek Environmental Center Birding Cup will take place May 6-7 and Migration Morning Walks begin at the Center on April 6 (7:00-8:30AM) continuing weekly through May 11. Registration is appreciated, but not required. See website: https://www.shaverscreek.org/public-programs-and-events/

Announcements:

A few SCBC logo hats are still available. If interested in purchasing one, contact Susan Smith.

Board member elections will be held at our regular April meeting. The nominating committee, Nick Kerlin, Greg Grove and Roana Fuller, is looking to fill positions for Treasurer, VP of Field Trips and 2 at large Board seats. Anyone interested in running, please contact members on the nominating committee.

Old Crow Wetland: Decisions about development of Rutters filling station above the wetland are reaching a critical phase. Last week at a regular meeting of the Huntingdon County planning committee, 20 supporters of Old Crow Wetland voiced their concerns, while Rutter’s representatives only briefly discussed their plans. This county committee only has an advisory role and does not make the final decision. The critical meeting of the Smithfield Planning Commission will take place on Tuesday, March 29. It is important that a large crowd opposing Rutter’s development come to this meeting in an effort to stop the proposed development. Greg Grove will send out more details on the listserv, but he is hoping that as many people come as possible to stand in support of the wetland and against the development. The township supervisors will be making a decision as early as the first week of April, so now is the time to show support for the wetland. For more information contact Greg Grove.

If you are curious about the listserv instructions, you may visit our website https://www.scbirdcl.org/joinemaillist.html. These instructions include a “digest” option which limits the daily emails from the group to a maximum of one per day. We are entering the “busy” season as we share first of year (FOY) birds we encounter and news on field trips etc.

Tussey Mountain Spring Hawk Watch

The migration count is well underway with close to 150 golden eagles and nearly 100 red tails tallied so far this season. Other species are making their way north and will be seen as spring progresses. Thanks to Gillian Martin for keeping us up to date on the count through the listserv each day. For details and the latest news you can also visit the website: https://tusseymountainspringhawkwatch.org/

Notable Bird Sightings: Greg Grove’s Summary

(Feb 24-March 23, 2022; Centre and its contiguous counties)

March is the month of ducks moving though our region. Long-tailed ducks and horned grebes were among the more unusual sightings. A Sandhill crane was in the area in mid-March.  American woodcocks, common snipe and killdeer have been arriving and a greater yellowlegs was seen in early March. A lesser black-backed gull and white pelican were among the unusual species reported. Sadly, a dead red-throated loon was found on the road near Julian, probably a casualty of mistaking a wet road for a body of water as can be the case with loons. Only one shrike was recorded. The first purple martin return was recorded on March 21 and tree swallows are arriving now. A couple of early brown thrashers were seen and the 3 reports of catbirds are probably those that have remained here throughout the winter. Only a few cross-bills and pine siskins have been sighted since this has not been an irruption year. Lapland longspur and Harris sparrow have been reported. The orange-crowned warbler seen throughout the winter in State College continues. The first early warbler migrants include pine warblers and the first Louisiana waterthrush was reported a few days ago.

Speaker: Bruna Amaral: “Small bug, big impact: effects of hemlock woolly adelgid infestation on bird populations”.

(This entire presentation can be viewed at:
https://psu.zoom.us/rec/share/MCcjye5_Fx2FZk32r_8FbEUpYBwFErmsjwFcftKnkYurbMuebg67yKIsN2-VyY2_.OX1txUZx1IYVHuIY )

As a quantitative ecologist using statistics to understand birds’ response to habitat change, Bruna received her undergraduate degree in biology in Brazil, where she studied how understory birds in the Amazon rainforest are coping with second-growth forests. Currently pursuing her master's degree in ecology at Penn State, Bruna creatively presented her research, using entertaining and informative graphics. Her work helps to address the question: do landscape changes caused by adelgid infestation and subsequent hemlock mortality contribute to the loss of an estimated 170 million Eastern forest birds since 1970?

Bruna first discussed several examples of human mediated biological invasions, both intentional such as Starlings into the US and hippos into Columbia and accidental which includes the hemlock woolly adelgid (HWA).

The HWA, a small aphid-like insect accidentally introduced from Japan in 1950, feeds on sap of hemlocks and can cause tree death within 4-10 years after initial infestation. Temperatures influence the adelgids ability to infest and ultimately kill hemlocks. Higher mortality of adelgid occurs in colder temperatures found in the north with more than 90% HWA mortality in locations north of about 42 degrees latitude. Consequently, hemlock stands in the north are more protected from adelgid caused mortality than those in the southern parts of the hemlock’s range.

Hemlock stands provide a cool, dark, humid, relatively open habitat under their canopies providing an important habitat to a variety of bird, amphibian and fish species. Many studies have looked at the negative impact of adelgid infestation and subsequent hemlock death on local bird populations.  Because scale matters in ecological processes, Bruna’s study considers the large regional scale including all of the counties in the Eastern US where hemlocks are present.

To conduct her analysis, Bruna used several large data sources including US Forest Service data tracking adelgid infestations from 1951-2017, Breeding Bird Surveys (BBS) since 1966 and WorldClim temperature data. By overlapping these data sets, more than 1.5 million detections of birds from almost 800 BBS routes collected over 40 years were used in this study.

Bruna was able to compare bird population trends from adelgid infested and uninfested areas. She studied seven hemlock associated species (Acadian flycatcher, Blackburnian and magnolia warblers, blue-headed vireo, red-breasted nuthatch and hermit thrush) and compared them to eight control species (blue jay, cerulean and worm-eating warblers, eastern phoebe, red-eyed vireo, scarlet tanager, white breasted nuthatch, and wood thrush) that are not highly associated with hemlock habitats. She considered immediate as well as long term impacts of adelgid infestation on bird populations.

Three of seven hemlock associate species showed significant decline 20 years after adelgid infestation. Hermit thrush and Blackburnian warbler exhibited large long term population declines.  Red-breasted nuthatch exhibited both immediate and long-term population decline but their overall decline was less dramatic.

Response time of population decline after initial infestation ranged from 2-8 years. Hermit thrush and red-breasted nuthatch declines began 2 years after infestation and Blackburnian warbler declines began 8 years after.

As expected, among the control species studied, none showed decline after adelgid infestation. However populations of three species, scarlet tanager, white-breasted nuthatch and cerulean warbler, increased after adelgid infestation. These species may benefit from habitat changes due to death of hemlocks and subsequent increase in deciduous growth.

Populations of four hemlock associated species, (black-throated green and magnolia warblers, Acadian flycatcher and blue-headed vireo) were relatively unaffected by adelgid invasion. Populations of these four initially declined in response to adelgid infestation, but after 20 years, their populations recovered. In fact, magnolia warbler populations increased significantly after 20 years. Apparently these four species compensated for loss of hemlocks by using alternate habitats that include other conifer species such as spruce and pines. Apparently, habitat heterogeneity is buffering against some bird species population decline.

By looking at the large scale, ecological studies such as this one can take into account surrounding landscapes. This can help us understand population dynamics and explain why some hemlock associated species did not decline after adelgid infestation.

In conclusion, this study points to the importance of protecting a diversity of habitats to ensure species persistence. In addition, considering scale in ecological studies is important.  Population decline at the landscape scale appears to be less dramatic than is shown in studies at a more local scale due to birds using alternative habitat. However, some species did decline. And bird population decline in warmer areas is greater due to increase infestation and subsequent hemlock mortality.

Higher latitudes are currently protected against adelgid spread due to prolonged cold winter temperature. However, global climate change could negatively impact hemlock stands and bird populations in northern regions as temperatures rise.