DOI: 10.5061/dryad.3n5tb2rmq
title: Dataset for: Breeding populations of Marbled Godwits and Willets have high annual survival and strong site fidelity to managed wetlands

description: The Prairie Pothole Region of central Canada supports a diverse community
 of breeding waterbirds but many species have declining populations and the
 demographic mechanisms driving the declines remain unknown. We conducted a
 7-year field study during 1995–2001 to investigate the demographic
 performance of Marbled Godwits (Limosa fedoa) and Willets (Tringa
 semipalmata) breeding in managed wetlands near Brooks, Alberta.
 Mark-recapture analyses based on Cormack-Jolly-Seber models revealed that
 the annual rates of apparent survival for Marbled Godwits (phi-hat = 0.934
 ± 0.015SE) and Willets (phi-hat = 0.849 ± 0.018SE) are among the
 highest rates of survivorship reported for any breeding or nonbreeding
 population of large-bodied shorebirds. Our estimates of life expectancy
 for males were comparable to longevity records in godwits (E-hat = 17.3
 years ± 5.8SE vs. 25-29+ years) and Willets (E- hat = 7.7 ± 1.5SE vs. 10+
 years). The two species both showed strong breeding site fidelity but
 differed in rates of mate fidelity.  Pairs that reunited and
 males that switched mates usually nested &lt;300 m from their previous
 nests whereas females that switched mates usually moved longer distances
 &gt;1.1 to 1.5 km. Returning pairs usually reunited in godwits (85%)
 but not in Willets (28%), possibly because of species differences in adult
 survival or patterns of migration. Baseline estimates of annual survival
 for banded-only birds will be useful for evaluating the potential effects
 of new tracking tags or the environmental changes that have occurred
 during the past 20 years. Conservation strategies for large-bodied
 shorebirds should be focused on reduction of exposure to anthropogenic
 mortality because low rates of natural mortality suggest that losses to
 collisions at breeding sites or harvest at nonbreeding areas are likely to
 cause additive mortality.
description: Dates of data collection: We conducted a 7-year breeding study
 (1995–2001) of Marbled Godwits and Western Willets in Alberta.  Fieldwork
 at Kitsim was conducted by 2–6 shorebird observers from late April to
 mid-July with 37 to 67 days of nest searching, monitoring and captures in
 1995–2000, and 18 days of resighting effort in 2001. 
 Geographic locations of data collection: Fieldwork was conducted
 at the Kitsim wetland complex, located 13 km southwest of Brooks, Alberta
 (50.5042 deg N, 112.0459 deg W).  The core study area was northwest of the
 intersection of highways 539 and 36 and had an area of 21.6
 km<sup>2</sup> (3.3 km W-E by 6.5 km N-S).  Additional
 monitoring was conducted on two smaller patches to the west (2.7
 km<sup>2</sup>) and to the southeast (4.4
 km<sup>2</sup>) of the core study area. 
 Study species: The two study species were Marbled Godwits
 (<em>Limosa</em> <em>fedoa</em>) and Willets
 (<em>Tringa</em> <em>semipalmata</em>). The
 populations studied in Alberta were of the midcontinental subspecies
 (<em>L</em>. <em>f</em>.
 <em>fedoa</em>, and <em>T</em>.
 <em>s</em>. <em>inornata</em>).
description: Data files are .txt or .csv files that can be opened in Notepad
 or Excel. R scripts are text files (.R) that can be
 opened in Notepad or run in R version 4.2.0  The
 DBF/FPT files are pairs of database files that can be opened and evaluated
 with Program Mark version 9.0 Program Mark is available
 as a free download at http://www.phidot.org/software/mark/