Chasing the tides: Overwinter intertidal movements of Saltmarsh and Seaside Sparrows

Marae C. Lindquist1, Evangelyn L. Buckland1, John Carpenter2, Raymond M. Danner1

1University of North Carolina Wilmington Department of Biology and Marine Biology2North Carolina Wildlife Resources Commission

IntroductionThere are large gaps in knowledge regarding thewintering populations of Saltmarsh Sparrows(Ammospiza caudacuta, SALS) and SeasideSparrows (Ammospiza maritima, SESP). Bothspecies are listed as Species of GreatestConservation Need in the NC Wildlife ActionPlan. In 2023 the USFWS will determine if SALSshould be federally listed as Threatened orEndangered. During the winters of 2019 and2020 we are researching the winter populationbiology of SALS and SESP on Masonboro IslandNational Estuarine Research Reserve inSoutheastern North Carolina to estimatedensity, abundance, space use, and site fidelity.This is Cooperative Agreement between UNCWand the NC Wildlife Resources Commission.

Methods

Analysis: R package “sigloc” for the telemetry, linearmixed models to analyze daily movements, R package“adehabitatHR” to test kernel density estimates, andhabitat maps to analyze habitat use. We will also calculatea distribution function based on daily movement distanceand correct abundance estimates from mark andrecapture to estimate density within the study area.

Mist Netting

Mark Recapture

Radio Telemetry Triangulation

Future Research

AcknowledgmentsReferences[1] Wiest et. al 2016 The Condor[2] Post, W. et. al 2018 BNA[3] Greenlaw, J. S. et. al 2018 BNA[4] Greenberg, et. al. 2006. Book[5] Gedan, et. al. 2009. Annual Review of Marine Science[6]Bayard, T. S., and C. S. Elphick. 2011. The Auk

ImportanceHuman

development,sea level rise,storm severity, flooding events

Accretion

Marshcompression,degradation,

loss

Marsh obligates are of particular conservationconcern because their habitat is declining due toanthropogenic forces. It is important to makeinformed conservation strategies, but that isdifficult with limited population estimates [1]. SESPserve an important role as an indicator species ofmarsh health and SALS are a flagship species inwhich to focus conservation efforts [2,3].

HypothesesObjective 1: Describe movements throughout winter

Hypothesis 1: Daily movements will track with the tide

Hypothesis 2: High site fidelity throughout the winter

Hypothesis 3: Consistent and specific habitat use throughout the winter

Objective 2: Use data from objective 1 and mark-recapture to estimate density and abundance

Preliminary Results

H2: High site fidelity throughout the winter

Seem to have high site fidelity, remaining in same location throughout duration of the study

H1: Daily movements will track the tide

Found that the birds do track with the tide, yellow box indicates high tide habitat.

H3: Consistent and specific habitat use throughout the winter

Use same intertidal habitat over and over

[1,4,5,6]

We would like to thank the NC WRC and UNCW for fundingthis important research project. We also thank all of ourwonderful volunteers who have assisted in the first year offield work and all of the members of the Danner Lab!

Figure 1

Figure 2

Figure 3

Figure 4Figure 5

Figure 6

Figure 1: Two researchsites on Masonboro Island,NC—part of the NationalEstuarine Research ReserveSystem (NERRS).

Figures 2–4: Actively flushed ourstudy species into mist nest,banded them, and deployed 20radio tags. Our first season webanded 140 SESP and 13 SALSand 20 tags were deployed 15on SESP and 5 on SALS.

Figures 5–6: We tracked ourbirds using portable null peakradio telemetry towers. Weradio tracked 31 days fromFebruary to April. We usedtriangulation to find the birds’location within the marsh.

With the information we are gathering with this study we plan to:• Model how sea level rise across coastal North Carolina will affect suitable sparrow habitat, and in turn influence population sizes.• Attempt to refine population estimates for the state of North Carolina for SALS and SESP.• Help determine optimal habitat in order to assist with most effective conservation strategies.

For updates follow @danner_lab on Instagram

Radio Tagging