Disturbances related to changing environmental conditions, presence of predators and human activities are negatively impacting the reproduction of resident shorebirds globally. Evaluating the mechanisms by which these disturbances influence breeding shorebird populations will result in informed decisions to better conserve these species and their habitats. Plovers also serve as model systems to understand avian demography, behaviour, and mating systems. In South Africa, resident shorebirds have been understudied, which is surprising given the wealth of research groups working on this group in other parts of the world. This project joins global projects focusing on shorebirds to collect breeding and demography data for individually-marked populations of these species.

The project studies a common species, the Kittlitz’s Plover Charadrius pecuarius, and a species considered ‘near threatened’, the Chestnut-banded Plover C. pallidus. Data collection is focused on finding all breeding attempts at the study site annually and maintaining a marked population to track aspects of breeding biology, nest success and demography. When nests are successful, parental care and brood behaviour is documented with the goal of building a detailed understanding of the mating systems of these species, and how local conditions may shape strategies in comparison to populations elsewhere. The study site is at the Berg River estuary and the commercial salt pans near the town of Velddrif in the Western Cape. It is recognised as an Important Bird and Biodiversity Area (IBA) with its high number of breeding and wintering waterbird species. The project was piloted in 2019, with the first field season initiated in 2020 and the fifth breeding season monitored in 2024.

Activities in 2024

  • CB MSc student Claude Schippers led the 2024 field season between September and November. A new record season total of 128 nesting events were documented, including 51 Kittlitz’s (KiP) and 68 Chestnut-banded plover (CbP) nests, with an additional 3 KiP and 6 CbP nesting events found as broods. Nest survival during the season was exceptionally high with about 55% of KiP nests and about 60% of CbP nests of known fate hatching (excluding those found as broods). Nest predation was a main cause of failure, along with weather events and human related trampling.
  • The focus research question of the breeding season was evaluating the impacts of disturbance on the breeding success of both plover species. Claude scored all human visits to the salt pans to quantify disturbance in space. He also conducted flight initiation trials on the incubating birds to explore how various factors impact flight initiation distance.

Highlights

  • Dr Carina Nebel evaluated both Kittlitz’s and Chestnut-banded Plovers for the South African red data list.

Impact of the project
This study informs conservation efforts as it occurs at a designated IBA, which primarily holds important populations of waders and other waterbirds. It aids understanding of the threats to these species, helping to protect them from current and future threats. In terms of evolutionary ecology, this project provides information on the breeding and demography of these shorebird populations and will evaluate the mating system variation in the population at this site to determine whether it is linked to sex ratios, demography or other environmental/life history factors.

Key co-supporters
University of Bath; Élvonal Shorebird Science network at University of Debrecen, Kuifkopvisvanger accommodation.

Research team 2024
Team leaders and collaborators:
A/Prof. Robert Thomson (FIAO, UCT)
Prof. Tamás Székely (Univ. Bath and Univ. Debrecen)
Dr Naerhulan Halimubieke (Univ. College London)
Dr Anthony Lowney (U. Hartpury, FIAO Research Associate)
Melisa Bal (KAB Ecology)
Anaïs Paturle (U. Groningen)
Dr Carina Nebel (U. Turku)

Student:
Claude Schippers (CB MSc, UCT)