Breeding success of Black-crowned Night Heron (Nycticorax nycticorax), Little Egret (Egretta garzetta) and Cattle Egret (Bubulcus ibis) (Aves: Ardeidae) in relation to nest height in the South Caspian Sea

Abstract

Breeding success was investigated in a mixed colony of three species of Ardeidae (Black-crowned Night Heron, Nycticorax nycticorax; Little Egret, Egretta garzetta; and Cattle Egret, Bubulcus ibis) in the Karfestan colony, south Caspian Sea, during the 2006 breeding season. Black-crowned Night Herons occupied higher locations for nesting (4.39 ± 1.44 m) than both Little Egrets (3.07 ± 1 m) and Cattle Egrets (2.8 ± 0.84 m). Clutch size appeared to be independent of the height of the nest from the ground in all species. Mean breeding success was 0.82 ± 0.24, 0.80 ± 0.16 and 0.77 ± 0.17 in the Black-crowned Night Heron, Little Egret and Cattle Egret respectively. Overall breeding success did not vary significantly among the three species. Fledging success and overall breeding success were associated with nest height in the Black-crowned Night Heron, with a tendency for the higher nests to be more successful. Nest height was also correlated with fledging success in the Cattle Egret but had no effect on breeding success in the Little Egret.

Factors affecting offspring growth and daily nest survival rates in the coastal breedingWesternReefHeron (Egretta gularis) in thePersianGulf

“…Fledging success and overall breeding success were associated with nest height in the Black‐crowned Night Heron, with a tendency for the higher nests to be more successful. In comparison, nest height was also correlated with fledging success in the Cattle Egret but had no effect on breeding success in the Little Egret (Ashoori & Barati ). The same relationships have been reported for other egrets in Spain (Parejo et al .…”

“…() found no evidence that the range of nest heights encountered in their study had any effect on mean reproductive success. In Northern Iran, nest height was not correlated with any of the breeding parameters of the Little Egret ( Egretta garzetta ) and was correlated only with fledging success in the Cattle Egret ( Bubulcus ibis ) (Ashoori & Barati ). Fledging success and overall breeding success were associated with nest height in the Black‐crowned Night Heron, with a tendency for the higher nests to be more successful.…”

“…Nest size also affects the DSR of the nest of some species (Sperry 2006). Nest height and location of the nest within the breeding colony affected the survival of nests in different Ardeid species (Ashoori & Barati 2013). Neinavaz et al (2013) also reported a significant relationship between nest location and DSR in Great Egret (Ardea alba) colonies in the Persian Gulf.…”

“…Nest size also affects the DSR of the nest of some species (Sperry ). Nest height and location of the nest within the breeding colony affected the survival of nests in different Ardeid species (Ashoori & Barati ). Neinavaz et al .…”

Effects of nest characteristics and black rat Rattus rattus predation on daily survival rates of great egret Ardea alba nests in mangrove forest in the Hara Biosphere Reserve, the Persian Gulf

“…Our primary objective was to evaluate the influence of nest-site variables on the nesting success of great egrets, with particular interest paid to the potential negative impact of black rat predation. There is some evidence of advantages of nest height among Ardeidae (Fasola & Alieri 1992, Ashoori & Barati 2013). Nest diameter is also reported to be influential in nesting success in waterbirds (Childress & Bennun 2000, Barati & Behrouzi-Rad 2010.…”