TY - CHAP

T1 - The influence of climate on reproductive parameters of the Mute swan population in the eastern part of the Gulf of Finland

AU - Kouzov, S.A.

AU - Kravchuk, A.V.

N1 - Conference code: 7

PY - 2022/12

Y1 - 2022/12

N2 - We tested “the Living child-free hypothesis” (Solovyeva et al., 2019) using our Mute Swannesting data, collected on the Kurgalsky Peninsula in 2005-2021. The number of swans variedfrom 17–102 pairs/year, depending on temperature in the wintering grounds and the timing ofthe ice melt. We observed both territorial pairs and colonial nesting. All nests (n = 858) weredescribed and mapped. The total number of territorial pairs and their spatial distributionchanged very little, while the number of colonial pairs varied greatly (> 10-fold). Populationdeclines coincided with years of climatic pessimism. In colonies, the proportion of empty nestsand abandoned clutches increased, and the size of clutches and the success of incubationdecreased, both during the years of the greatest population declines and during the years ofstrong population growth. All reproductive parameters of territorial-nesting birds improvedwith population growth. Analysis of the breeding sites occupied by birds over many years (bothfor territorial and for colonial birds), and for territories and sites in colonies occupied for 1-3years, found that all long breeders (both in colonies and outside colonies) have improvedreproductive parameters at times of climatic maximum and population growth, and a decreasein overall reproductive indicators at population peaks due to a strong increase in the numberof short breeders in colonies. Long breeders in their first year of breeding had reproductiveparameters lower than in subsequent years. Thus, the observed “living child-free” effect maybe due to massive breeding attempts of young birds in colonies during the years of populationincreases.

AB - We tested “the Living child-free hypothesis” (Solovyeva et al., 2019) using our Mute Swannesting data, collected on the Kurgalsky Peninsula in 2005-2021. The number of swans variedfrom 17–102 pairs/year, depending on temperature in the wintering grounds and the timing ofthe ice melt. We observed both territorial pairs and colonial nesting. All nests (n = 858) weredescribed and mapped. The total number of territorial pairs and their spatial distributionchanged very little, while the number of colonial pairs varied greatly (> 10-fold). Populationdeclines coincided with years of climatic pessimism. In colonies, the proportion of empty nestsand abandoned clutches increased, and the size of clutches and the success of incubationdecreased, both during the years of the greatest population declines and during the years ofstrong population growth. All reproductive parameters of territorial-nesting birds improvedwith population growth. Analysis of the breeding sites occupied by birds over many years (bothfor territorial and for colonial birds), and for territories and sites in colonies occupied for 1-3years, found that all long breeders (both in colonies and outside colonies) have improvedreproductive parameters at times of climatic maximum and population growth, and a decreasein overall reproductive indicators at population peaks due to a strong increase in the numberof short breeders in colonies. Long breeders in their first year of breeding had reproductiveparameters lower than in subsequent years. Thus, the observed “living child-free” effect maybe due to massive breeding attempts of young birds in colonies during the years of populationincreases.

M3 - Conference abstracts

BT - 7th International Swan Symposium & 26th Trumpeter Swan Society Swan Conference

CY - Jackson

T2 - 7th International Swan Symposium & 26th Trumpeter Swan Society Swan Conference

Y2 - 23 October 2022 through 27 October 2022

ER -