A Bird’s Eye View: Investigating Piping Plover Predation, Associated

Behaviours and Management Techniques.

MSc Candidate, Gabrielle BeaulieuDalhousie University

Project Context• Piping Plover (Charadrius melodus melodus) 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.

1. Identify predators using video2. Compare reproductive success at exclosed/ non-exclosed3. Compare behaviours at exclosed/ non-exclosed 4. 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

n Kejimkujik NP Kouchibouguac NP PEI NP

2008 6 1 1 4

2009 8 0 3 5

Footage (hrs) ~ 350 ~ 1200 ~ 1600

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)

Nest Hours Watched

Predator

Corvid fly Corvid walk Gull Fly Gull walk Fox Coyote Raccoon Other (tern, bird)

CavS1 56 2 1

CP 76 2*

GR1 87 35 tern

GR3 122 2 tern +2 mouse

Total 341 2 3 39 * 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

Preliminary Results - Identify predators

• 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

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

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

Exclosed Nests Unexclosed Nests Total

Hatched Flooded Abandoned Depredated Hatched Flooded Abandoned Depredated Kouch 4 1 0 4 1 0 1 11

PEI 3.5* 0.5* 1 0 2 2 0 1 10

Total 7.5 0.5 2 0 6 3 0 2 21

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

Factor t df p-value Vigilance -1.4231 633.253 0.1552

Away -1 8 0.3466 Movement 0.2926 70.704 0.7707

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

AcknowledgementsDr. Marty LeonardDr. Deborah Austin

Piping Plover Resource Conservation Teams inKejimkujik, Kouchbouguac and PEI National Parks

Piping Plover Camera Project Volunteers

Funding:Parks Canada Canadian Wildlife Service Southern Gulf of St. Lawrence CoalitionTim Horton Children’s Foundation