DOI: 10.5061/dryad.2ngf1vhtk
title: Human-wildlife interactions on the tidal flats of the Bijagós archipelago: does shellfishing affect migratory shorebirds?

description: The Bijagós archipelago in West Africa is home to an ethnic group with a
 rich cultural heritage that is tightly linked to nature. The Bijagós
 people have a shared cultural identity, but across islands, there are
 different resource management regimes stemming from island-specific
 context with regards to socio-political organization and strength of
 cultural heritage. Across the archipelago, bivalves harvested manually
 from the mudflats are an important part of the Bijagós people’s diet,
 economy, and culture. Thousands of migratory shorebirds share the use of
 these mudflats during their non-breeding season, consuming macrobenthos
 such as crustaceans and bivalves, including those harvested by local
 people. At the end of their stay in the Bijagós, shorebirds need to fuel
 for their migratory flight in order to return to their breeding areas,
 being particularly important during this period that they have access to
 undisturbed feeding areas with suitable food resources. In this study, we
 start by exploring shellfishing patterns across different management
 regimes, then assess seasonal variation in the direct impact of
 shellfishing on shorebirds (through competition for resources and space),
 and finally quantify the indirect impact of sediment disturbance due to
 shellfishing upon shorebird prey availability. Results indicate that
 bivalve resources are better managed in areas with formal protection,
 while traditional management based on cultural beliefs results in poorer
 stock conditions. Interestingly, across islands shellfishing activity is
 concentrated in mid-winter, decreasing towards shorebirds’ fuelling
 period, when they benefit the most from reduced disturbance on the
 mudflats. No direct competition for resources was detected, as collected
 bivalves were significantly larger than those consumed by shorebirds,
 regardless of the season. Indirect impacts caused by sediment disturbance
 during shellfishing were also mostly absent, causing only a small
 reduction on shorebirds prey density, but with no effect on the available
 biomass.
description: # Title of Dataset Human-wildlife interactions on the tidal flats of the
 Bijags archipelago: does shellfishing affect migratory shorebirds? Give a
 brief summary of dataset contents, contextualized in experimental
 procedures and results. ## Description of the data and file structure Data
 is structured in 3 separate sheets, refering to 3 different methodologies,
 described in the methods section of the main article. Description of
 "Hand-raking experiments" sheet: * Column "Species"
 refers to the hand-raked bivalve species (Comb or Lingron) * Column
 "Treatment" refers to the treatment of the plot (T = treated
 plot by hand-raking the sediment and colection of the target bivalve, C =
 control plot, not hand-raked) * Column "Day" refers to the time
 of sample collection (Day 1 = The day of the experiment; Day 15 = 15 days
 after the experiment; Day 0 = experimental plot hand-raked before
 receiving the treatment later that day) * Column "Core" refers
 to the numer of the collected sediment core (sequencial from 1 to 7) *
 Column "position" refers to the position of the sediment core
 sample (T= top 5cm of * the sediment corer; B = Bottom 10 cm of the
 sedimente corer) * Column "point" refers to the sampling point
 specific code (7 points collected in each plot/treatment) * Column
 "storage" refers to where the stogare code for posterior
 consultation (storage "field" refers to individuals measured in
 the field and not stored) * Column "sp" refers to the
 macrobenthos taxa found in the sediment sample Column * "TL"
 refers to the Total Length (in mm) of each individual found in the
 sediment sample Description of "Bivalve Size Measurments" sheet:
 * Column "Date" refers to the date when the bivalve was measured
 * Column "period" refers to the period of the migratory
 shorebird's stay in the Bijagos (Wintering or Fuelling, see methods
 on paper for further detail) * Column "site" refers to the site
 where the measured bivalve was collected * Column "species"
 refers to the species of the bivalve measured * Column "TL"
 refers to the Total Length (in mm) of each individual bivalve measured
 Description of "Mudflat presence" * Column "Date"
 refers to the date when the number of people on the mudflats was counted *
 Column "period" refers to the period of the migratory
 shorebird's stay in the Bijagos (Wintering or Fuelling, see methods
 on paper for further detail) * Column "site" refers to the site
 where the number of people on the mudflats was Counted * Column
 "time" refers to the time when the number of people on the
 mudflats were counted * Column "n" refers to the number of
 people of each category counted * Column "gender/age" refers to
 the social category of people present of the mudflat (W = women, M = man;
 K = kid) * Column "activity" refers to the activity each
 category of people was performing on the mudflat