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A Bird’s Eye View: Investigating Piping Plover Predation, Associated Behaviours and Management Techniques. MSc Candidate, Gabrielle Beaulieu Dalhousie University. Project Context.
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A Bird’s Eye View:Investigating Piping Plover Predation, Associated Behaviours and Management Techniques. MSc Candidate, Gabrielle Beaulieu Dalhousie University
Project Context • Piping Plover (Charadriusmelodusmelodus) is a small shorebird endemic to North America and Listed as Endangered by COSEWIC since 1985 • Recovery across all regions is threatened by habitat loss and degradation, human disturbance (e.g. recreation on beaches) and predation • Extensive monitoring of productivity and predation events in National Parks • Until now, predator identification has been mainly anecdotal and difficult to confirm indefinitely • Recent studies suggest a link between the use of a predator management tool (nest exclosure), nest abandonment and predation
Project Overview Overall goal: Determine impact of predators on Piping Plover reproductive success and parental behaviour, and to test effectiveness of current management tools. • Identify predators using video • Compare reproductive success at exclosed/ non-exclosed • Compare behaviours at exclosed/ non-exclosed • Do nest exclosures attract predators?
Project Overview • Conducting field work in Kouchibouguac and PEI National Parks during 2010 and 2011 • Piping Plover breeding season begins late April and the adults and fledged chicks migrate south from mid-July until late August • Field season from May 1st until August 30th • Majority of work involves searching for nests and observing breeding pairs during nest incubation • Year-end productivity is a count of the number of fledglings per breeding pair, making for a long field season
Pilot data – 2008, 2009 Video Monitored Piping Plover Nests in National Parks– 2008, 2009 • Events Captured : • Predation and harassment by fox (n=2, 3) • Predation and harassment by crow ( n =3, 17) • Harassment by gull (n = 1) • Avian predators perching on exclosures (n= 3)
Preliminary Results -Identify predators • * This nest was predated the day it was due to hatch, only video identified the predator as a crow • A total of ~1200 hours of nest video footage was collected in 2010 in Kouchibouguac and PEI National Parks • From 340 transcribed hours: 1 predation event, 5 predator sightings, 37 tern disturbances • Still about 678 hours to go through with the help of dedicated volunteers
Preliminary Results - Identify predators KN7: 259 hours of video footage (July 8-19, 2010) 25 reactions, 3 displays and 22 departures Fig 1. Number of animal sightings from video footage of a Piping Plover nest • This particular nest illustrated how the dune edge serves as a travel corridor • Surprisingly, even with all the animal traffic, this non-exclosed nest hatched
Preliminary Results –Reprod. Success • A total of 21 nests in 2010 were initiated • Of those, 13 nests hatched, two were abandoned, three were flooded and two were depredated • One predation event occurred in PEI and was captured on video Table 1. Reproductive success of Piping Plovers in Kouchibouguac and PEI National Parks during 2010 * The ‘half’ values refer to a nest that was flooded, and its re-nest included two eggs that had been flooded; two chicks hatched
Preliminary Results– Plover Behaviour • In addition to video data, I am conducting 30 minute focal observations of incubating parents (n = 17 nests 2010) • I am recording a measure of alertness, or vigilance, as the number of scans/minute of an incubating adult • I also record the number of times a plover is away from a nest and the number of movements it does while incubating • When monitoring nesting Piping Plovers, they are literally invisible until they move, it is thought that visual predators cue in on this • Their level of alertness (vigilance) should vary according to their level of stress or exposure to predators
Preliminary Results – Plover Behaviour • Welch’s two-sample t-tests were used to determine whether the behaviour of incubating Piping Plovers differs between exclosed and unexclosed nests • Small sample size n = 9 exclosed, n = 8 non-exclosed • a- posteriori Power analysis conducted Table 2. Two-sample t-test outputs for behaviour measurements comparing exclosed and unexclosed nests
Preliminary Results – Plover Behaviour Fig 2. Changes in Piping Plover vigilance during focal observations of one incubating adult • Vigilance seems to vary with time and sometimes changes in response to the presence of potential predators • Only 5 of the n = 17 nests observed changed their behaviour in response to the presence of potential predators
Preliminary Results – Exclosure as Cue • Artificial nest experiment 2011 season • Do exclosures act as a cue to predators when searching for food (nests)? • Determine whether exclosed nests are visited more frequently and by a greater variety of predators than non-exclosed nests • A total of 40 artificial nests, half exclosed • Will use motion detection cameras to identify predators and time of ‘predation’ as well as track surveys • June 15th – 30th simultaneously at both field sites
What does it all mean? • We have confirmed that foxes and crows predate Piping Plover nests • Both foxes and crows will empty a nest of eggs and carry away eggs one after the other over a period of several minutes to over a few hours • Some predators use nest exclosures to perch on • Plovers will elicit anti-predator behaviours towards a large variety of animals • Travel corridor along dune edge, greater risk to these nests • Thus far, plover behaviour does not seem to differ between exclosed and unexclosed nests • Vigilance varies greatly over time and between individuals • Some individuals seem more sensitive (in terms of vigilance) to the presence of predators than others
What does it all mean? • Nest exclosure design has been modified within Parks • Predator survey protocols are being implemented by all plover monitoring groups in 2011 • Public education and volunteer engagement has been key to continued research and modifying protocols • Increased sample size and further statistical analyses are required to answer research questions
Acknowledgements Dr. Marty Leonard Dr. Deborah Austin Piping Plover Resource Conservation Teams in Kejimkujik, Kouchbouguac and PEI National Parks Piping Plover Camera Project Volunteers Funding: Parks Canada Canadian Wildlife Service Southern Gulf of St. Lawrence Coalition Tim Horton Children’s Foundation