THE ROLE OF NOVEL FOOD WEBS IN REGULATING BIODIVERSITY AND ECOSYSTEM SERVICES IN URBAN-SUBURBAN ENVIRONMENTS IN NEW ENGLAND

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: MCINTIRE-STENNIS
• Reporting Frequency: Annual
• Accession No.: 0233737
• Project Start Date: Oct 1, 2012
• Project End Date: Sep 30, 2017
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UNIV OF MASSACHUSETTS
(N/A)
AMHERST,MA 01003

Performing Department
Environmental Conservation

Non Technical Summary
Humans are reshuffling the cards for animal and plant communities worldwide. Nowhere is this more evident than in our rapidly expanding cities and suburbs. In these highly human-modified environments, never before seen combinations of species exist in novel and sometimes extreme physical environments, such as highly invaded forest fragments in the suburban wilds. But what is the conservation potential of these urban-suburban green spaces And how should they be managed to maximize their value for critical taxa like migratory birds Urban-suburban food webs have only recently begun to be examined. Work to date has emphasized bottom up drivers influenced by humans such as water (e.g. lawn watering), nutrients (e.g. fertilizers), and food supplementation (e.g. bird feeders). But humans have recognized impacts on top down forces as well, through introduced predators (e.g. cats), removal of top predators (e.g. wolves), and food supplementation, both directly and through garden plantings or refuse. The changes in top down forces in urban food webs are less well understood, but have the potential to dramatically impact reproductive success of key taxa of interest, such as neotropical migratory birds. We have developed a study system that allow us to examine food webs in green spaces, varying in their degree of novelty from un-invaded forest fragments to highly invaded ones. The relatively unmanaged nature of these sites provides an opportunity to examine how novel combinations of plant species alter the dynamics of herbivory, predation, and brood parasitism for bird communities. We measure these impacts on the reproductive success of a declining migratory bird species, the Wood Thrush (Hylocichla mustelina). Understanding this study system will reveal new insights into the role of top down forces in urban food webs as well as providing an assessment of the strategies necessary to manage the conservation potential of urban-suburban green spaces. Specific management outcomes from our project will include: 1) identifying habitat conditions that promote healthy wood thrush populations in suburban forest fragments that will be directly applicable to informing conservation efforts for wood thrushes, and by extension other forest species and 2) quantification of the conservation benefits of active management of cowbirds in highly invaded suburban forest fragments. Investments in these management activities are regularly undertaken by municipal, state, federal, and non-profit groups, but experimental studies of the effectiveness of these methods are rare.

Animal Health Component

25%

Research Effort Categories

Basic

75%

Applied

25%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
135	0850	1060	50%
136	0820	1060	50%

Knowledge Area
135 - Aquatic and Terrestrial Wildlife; 136 - Conservation of Biological Diversity;

Subject Of Investigation
0820 - Wild birds; 0850 - Wildlife habitats;

Field Of Science
1060 - Biology (whole systems);

Keywords

migratory bird

suburbanization

food web

forest fragmentation

wood thrush

Goals / Objectives
The goals of the project are as follows: 1.Observe effects of predation and cowbird parasitism on reproductive success of the Wood Thrush, a declining neotropical migrant bird species, in suburban forest fragments along a gradient of understory plant invasion (from no invasive plant cover to dominance of invasives). 2.Measure the association between invasion and bird community composition in suburban forest fragments 3.Manipulate effects of cowbird parasitism on Wood Thrush nesting success through cowbird trapping and removal

Project Methods
We plan to experimentally manipulate top down forces affecting key taxa of focus in suburban forest fragments. We propose to study wood thrushes at 10 sites in Hampshire County, each adjacent to suburban development, and varying in the degree of multiflora rose invasion. We have mapped the distribution and percent cover of multiflora rose in these sites in 2012. The sites range from those with virtually no multiflora rose to those with the majority of the site covered with rose. We will conduct weekly bird counts throughout the breeding season to characterize the bird communities at each site. We will search for and monitor wood thrush nests, track radio-tagged wood thrush fledglings and measure habitat variables, patch and landscape characteristics, as well as the abundance of potential nest predators and cowbirds and deer at all sites. Nest and fledgling survival will be analyzed as a function of habitat, patch and landscape characteristics, as well as predator, parasite and deer abundance. Avian abundance and nesting success - To estimate abundance of wood thrushes, we will map territory boundaries of all individuals at our sites using the spot mapping method. To estimate bird productivity we will locate wood thrush nests at our sites and estimate nest survival by monitoring nests at 2-3 day intervals using standard protocols. Nest predators - We will use remote cameras to estimate the relative abundance of mesocarnivores. We will establish one camera station in the center of each site and bait the area with dry cat food and predator lure. Stations will be baited and monitored for 10 days. Using the photographs, we will catalog the number of individuals and visits as an index of relative abundance for comparison among sites. To estimate density of avian predators and sciurid rodents we will use fixed-radius point counts located at the center of each site. Each point will be sampled at least three times (May - July) when the observer will conduct a 10 minute point count broken into four 2.5 minute time periods recording all individual birds observed in two distance bands: near (0 - 50 m radius) and far (> 50 m). Using a fixed-radius point count (i.e. 0 - 50 m) will allow for density estimates for all avian nest predators. White-tailed deer - We will use remote cameras to estimate the relative abundance of white-tailed deer. We will establish one camera station in the center of each site and bait the area with shelled corn. Camera stations will be baited and monitored for 10 days. Using the photographs, we will catalog the number of individuals and visits as an index of relative abundance for comparison among sites. In collaboration with an ongoing Forest Service study, we will compare all of these parameters with the data from wood thrush populations in forested landscapes. After one year of observational data collection, characterizing the top down forces affecting Wood Thrush, we will begin trapping cowbirds to experimentally test whether top down forces (parasitism, in this case) have a significant effect on thrush reproductive success and whether this effect is greater or smaller in highly invaded forest fragments.

Progress 10/01/12 to 09/30/17

Outputs
Target Audience:The project provided internship experiences for 17 undergraduate students during the fall and spring semesters and 9 undergraduates during the summer, three of whom completed independent research projects and presented their work. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The project supported the development of three graduate students (Melanie Klein, Kit Straley, and Aaron Grade) who led all field efforts under supervision of the PIs. These students, in turn, mentored a total of 17 undergraduates undergraduate lab technicians who assisted with processing arthropod samples, video and camera data during the fall and spring semesters as well as 9 summer undergraduate field technicians who assisted with data collection in the field. Three undergraduates, including two women and one student from an underrepresented group, pursued independent research and presented their findings.One female student completed a senior honors thesis in Spring 2017, and her work is being incorporated into a publication in preparation. How have the results been disseminated to communities of interest?The PI and one of the graduate students (M. Klein) each presented the researchat a national conference (International Urban Wildlife Conference, San Diego, CA). What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? We continued to focus on objectives 1 and 2 this year. Across 12 sampling locations (6 suburban forest fragments, 6 inextensive forest), we searched for and monitored nests using standard protocols. We monitored a most nests withvideocameras to identify nest predators (Obj 1). We continued collecting additional data this year on invasive plant species (Obj 2),assessing food availability for nesting songbirds from fruit-bearing invasive shrubs as well as availability of insect prey, inrelation to the presence of invasive plants.

Publications

Progress 10/01/15 to 09/30/16

Outputs
Target Audience:The project provided internship experiences for 18 undergraduate students during the fall and spring semesters and 16 undergraduates during the summer, three of whom completed independent research projects and presented their work. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The project supported the development of three graduate students (Melanie Klein, Kit Straley, and Aaron Grade) who led all field efforts under supervision of the PIs. These students, in turn, mentored a total of 18 undergraduates undergraduate lab technicians who assisted with processing arthropod samples, video andcamera data during the fall and spring semesters as well as 16summer undergraduate fieldtechnicians who assisted with data collection in the field. Three undergraduates, including two women and one student from an underrepresented group, pursued indpendent research and presented their findings. How have the results been disseminated to communities of interest?One of the graduate students gave presentations to a local environmental education center and to students at Hampshire College. The PI presented research at a national conference (Ecological Society of America). What do you plan to do during the next reporting period to accomplish the goals?Data collection will proceed in 2017 in the same manner as in 2016. In addition, Melanie Klein (graduate student) continues to analyze and write about her findings from Objective 1 and hopes to submit a publicationin 2017.

Impacts
What was accomplished under these goals? We continued to focus on objectives 1 and 2 this year. Across 12 sampling locations (6 suburban forest fragments, 6 in extensive forest), we searched for and monitored nests using standard protocols. We monitored a most nests with videocameras to identify nest predators, and we carried out point count sampling for both predators and nesting birds, including the Wood Thrush (Obj 1). We continued collecting additional data this year on invasive plant species (Obj 2), assessing food availability for nesting songbirds from fruit-bearing invasive shrubs as well as availability of insect prey, in relation to the presence of invasive plants.

Publications

Progress 10/01/14 to 09/30/15

Outputs
Target Audience:The project provided internship experiences for 4 undergraduate students during the fall and spring semesters and 4 undergraduates during the summer. Changes/Problems:We are finding very little cowbird parasitism, suggesting that pursuing Objective 3 will not be practical. However, we think the information we obtain from Objectives 1 and 2 will make significant contributions toward addressing the research questions we originally proposed. What opportunities for training and professional development has the project provided?The project supported the development of three graduate students (Melanie Klein, Kit Straley, and Michalagh Stoddard) who led all field efforts undersupervision ofthe PIs. These students, in turn, mentored a total of 4 summer undergraduate field technicians who assisted with data collection and 4 undergraduate lab technicians who assisted with processing video and camera data during the fall and springsemesters. How have the results been disseminated to communities of interest?The PI gave an invited presentation at the 10th International Conference on Behavior, Physiology, and Genetics of Wildlife on September 28 in Berlin, Germany. What do you plan to do during the next reporting period to accomplish the goals?Data collection will proceed in 2015 in the same manner as in 2014. In addition, Melanie Klein (graduate student) is analysing her findings from Objective 1 and will be writing a publication for submission in 2016.

Impacts
What was accomplished under these goals? We continued to focus on objectives 1 and 2 this year. Across 12 sampling locations (6 suburban forest fragments, 6 in extensive forest), we searched for and monitored nests using standard protocols. We monitored a most nests with videocameras to identify nest predators, and we carried out point count sampling for both predators and nesting birds, including theWood Thrush (Obj 1). We continued collecting additional data this year on invasive plant species (Obj 2), assessing food availability for nesting songbirds from fruit-bearing invasive shrubs as well as availability of insect prey, in relation to the presence of invasive plants. We began assessing condition of forest patches in Springfield, MA in order to expand our sample to include a more highly urbanized area.

Publications

Progress 10/01/13 to 09/30/14

Outputs
Target Audience: The project provided internship experiences for 3 undergraduate students during the spring semester and 4 undergraduates during the summer. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? The project supported the development of two graduate students (Melanie Klein and Kit Straley) who led all field efforts under supervision of the PIs. These students, in tern, mentored a total of 4 summer undergraduate field technicians who assisted with data collection and 3 undergraduate lab technicians who assisted with processing video and camera data during the fall and spring semesters. How have the results been disseminated to communities of interest? We gave one presentation from this work at the Northeast Natural History Conference in April 2014. What do you plan to do during the next reporting period to accomplish the goals? Data collection will proceed in 2015 in the same manner as in 2014. In addition, Melanie Klein (graduate student) is analysing her findings from Objectives 1 and 2 and will be writing her thesis and submitting publications.

Impacts
What was accomplished under these goals? We focused on objectives 1 and2 this year. Across 20 sampling locations (10 suburban forest fragments, 10 in extensive forest), we searched for and monitored nests using standard protocols. We monitored a subset of nests with video cameras to identify nest predators, and we carried out point count sampling for both predators and nesting birds, including the Wood Thrush. We began collecting additional data this year on invasive plant species, assessing food availability for nesting songbirds in the vicinity of 10 plant species, including the 5 most common invasive plant species and 5 native plant species for comparison.

Publications

Progress 10/01/12 to 09/30/13

Outputs
Target Audience: The project provided internship experiences for 3 undergraduate students during the summer. Changes/Problems: Cowbird parasitism is low in our study sites. Therefore, we may need to restrict our activities to addressing objectives 1 and 2 (focusing on predation and nesting success). We will not likely be able to manipulate cowbird parasitism (objective 3). What opportunities for training and professional development has the project provided? The project supported the development of one graduate student (Melanie Klein) who led all field efforts under supervision of the PIs. She, in tern, mentored 3 summer interns who assisted with data collection. How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? We will repeat the efforts to address objective 1, expanding the number of nests monitored with video cameras to capture additional predation events. We will also expand the number of sites sampled.

Impacts
What was accomplished under these goals? We focused on objective 1 for our first year of the project. Across 20 sampling locations (10 suburban forest fragments, 10 in extensive forest), we searched for and monitored nests using standard protocols. We monitored a subset of nests with video cameras to identify nest predators, and we carried out point count sampling for both predators and nesting birds, including the Wood Thrush.

Publications