Variation in nest survival of three species of tropical plovers in Madagascar with clutch size, age of nest, year and El Niño effect

Abstract

A combination of life history traits and environmental conditions has been highlighted as the main drivers of avian breeding success. While drivers of breeding success are well known in some species, especially birds in northern, temperate regions; species in other parts of the world have received relatively little attention. In this study, we used a long-term dataset on breeding success of tropical plovers from south-west Madagascar to investigate whether nest survival changed over time and whether the drivers of nest survival were similar for multiple species breeding in the same arid habitat. In the 12-year period of 2009-2020, we monitored 2077 nests for three species with different breeding strategies: 1185 nests of Kittlitz's plovers (Anarhynchus pecuarius) with a flexible breeding strategy and uniparental care; and 565 nests of white-fronted plovers (A. marginatus) and 327 nests of Madagascar plovers (A. thoracicus) which both have biparental care. We found that nest survival was associated with a combination of clutch-size, age of nest and year among the three plover species. In addition, annual variation in climatic conditions associated with El Niño/La Niña events were included in the most supported survival models for Kittlitz's and white-fronted plovers, but the effects were not significant. Overall estimates of daily nest survival were similar for all three species: Kittlitz's plover: 0.950 ± 0.002 SE, Madagascar plover: 0.919 ± 0.007 SE, and white-fronted plover: 0.862 ± 0.047 SE. Estimates of nest success for the breeding season, based on increases in daily nest survival with the clutch age during the incubation periods (26 days for Kittlitz's plovers and 29 days for Madagascar and white-fronted plovers), were relatively low: Kittlitz's plover: 0.161 ± 0.056 SE, Madagascar plover: 0.287 ± 0.022 SE, and white-fronted plover: 0.228 ± 0.019 SE. All three species had a combination of factors affecting nest survival, both environmental and life history traits.

Keywords: Madagascar; clutch size; incubation; nest success; nest survival; reproductive strategies; shorebird; wader.

FIGURE 1

Probability of daily nest survival (95%CI, sample size of nests) in relation to clutch size for three species of tropical plovers in Madagascar. One egg clutches in black, 2 egg clutches in light grey and 3 egg clutches in dark grey. Parameter estimates taken from the “Clutch size” models.

FIGURE 2

Estimated daily nest survival (95%CI) in relation to age of nest for three species of tropical plover in Madagascar. Kittlitz's plovers (KiP) in black with a solid line, Madagascar plovers (MP) in light grey with a short dashed line and white‐fronted plovers (WfP) in dark grey with a long dashed line. Parameter estimates taken from model (nest age).

FIGURE 3

Daily nest survival (95%CI, sample size of nests) of Malagasy plovers over the 12‐year study period of 2009–2020. Kittlitz's plovers (KiP) in light grey, Madagascar plovers (MP) in mid grey and white‐fronted plovers (WfP) in dark grey. The missing estimates in 2011, 2012 and 2020 are years without nesting records for Kittlitz's and Madagascar plovers. For Kittliz's plovers, no nests were found during these years. For Madagascar plovers, nests for this species were not recorded in 2012 despite a low number of pairs breeding during this year. Daily nest survival estimates were taken from the “Year” model.

FIGURE 4

Probability of daily nest survival in relation to El Niño (a warm and dry climatic effect) or La Niña (a cool and wet climatic effect) events in each species with 95% CI. El Niño events in light grey, Normal events in black and La Niña in dark grey. Parameter estimates taken from model (El Niño/La Niña).