King Eider (Somateria Spectabilis) Brood Ecology: Correlates of Duckling Survival

Abstract

Events during duckling growth can influence waterfowl population dynamics. To gain insight into King Eider (Somateria spectabilis) brood ecology, we monitored 111 and 46 individually marked ducklings from broods of 23 and 11 radiomarked King Eiders during 2000 and 2001, respectively. We used capture-mark-resight data to model apparent survival of King Eider ducklings and broods, and multistratum analysis to estimate probabilities of (1) movement among habitats and (2) apparent survival of ducklings that used various habitats. In addition, we recorded length of stay for 7 and 18 radiomarked females with failed nesting attempts during 2000 and 2001, respectively. Complete loss of individual broods accounted for 84% of all duckling mortality (106 of 126 mortalities), with most brood loss (74%; 17 of 23 broods lost) within the first two days after hatch. Estimated apparent survival of ducklings to 24 days of age was 0.10 (95% CI: 0.05 to 0.15). Apparent survival of broods was estimated to be 0.31 (95% CI: 0.13 to 0.50). Our data suggested an interaction between female size and hatch date, whereby larger females whose ducklings also hatched earlier raised more ducklings than either small females or those with ducklings that hatched later. Overland brood movements ≥1 km occurred in both years, and survival was greatest for ducklings on smaller ponds away from the central nesting area at Karrak Lake, Nunavut. Females that experienced nest failure and total brood loss left the study area earlier than females with surviving ducklings.Écologie d'élevage des couvées de Somateria spectabilis : Corrélations avec la survie des canetons

Population dynamics of king eiders breeding in northern Alaska

“…Phillips and Powell (2009) estimated brood survival for king eiders at Kuparuk, Alaska, but were unable to estimate the duckling survival estimates needed for this model and their sample sizes were small. Their estimates of brood survival (0.1, 95% CI: 0.02–0.49) were lower, but overlapped brood survival estimates from Karrak Lake (0.31, 95% CI: 0.13–0.5; Mehl and Alisauskas 2007) and we are possibly biasing our estimate of λ high by using the Canadian estimates. Additionally, we re‐ran the model with duckling survival as a beta distribution using the above mean estimate of survival with an estimate of process variance calculated from a 13‐year study of common eiders in Scotland (Wilson 2007).…”

“…We used published estimates for king eider duckling survival from hatch to 24 days at Karrak Lake in northern Canada (Mehl and Alisauskas 2007) as a deterministic point in the matrix model (Table 1). Phillips and Powell (2009) estimated brood survival for king eiders at Kuparuk, Alaska, but were unable to estimate the duckling survival estimates needed for this model and their sample sizes were small.…”

“…Until recently, little was known about king eider life history (e.g., Lamothe 1973, Cotter et al 1997, Kellett and Alisauskas 1997), partly because they typically nest in remote locations at low densities and winter on the ice in largely inaccessible locations. However, studies from the last decade in northern Alaska and Canada lead to better parameter estimates for various life‐history stages (e.g., Kellett et al 2003, Mehl 2004, Mehl and Alisauskas 2007, Bentzen et al 2008, Phillips and Powell 2009, Oppel and Powell 2010).…”

Dispersal, movements and site fidelity of post‐fledging King EidersSomateria spectabilisand their attendant females

“…The hatch‐year birds were almost fully grown when trapped between 16 and 22 August, and were in family groups (Kuparuk) or crèches (near Teshekpuk Lake). It is not known whether the associated females were related to the hatch‐year birds they were captured with, but we assumed they were successful breeders in that year based on evidence that females leave the breeding area shortly after nest failure or brood loss (Phillips & Powell , Mehl & Alisauskas ). We erected funnel traps along the shoreline or mist‐net arrays in shallow ponds and used kayaks or waded to herd ducklings and adults into the traps or nets.…”

Temporary Communal Brooding in Northern Bobwhite and Scaled Quail Broods

“…Although, little is known regarding temporary communal brooding in gallinaceous species, this brooding strategy has been anecdotally observed in waterfowl and shorebird species including Mallards (Anas platyrhynchos; Boos et al 1989), King Eider (Somateria spectabilis; Mehl et al 2007), and Bristle-thighed Curlews (Numenius tahitiensis; Lanctot et al 1995). In waterfowl and shorebird species, temporary communal brooding has been hypothesized to occur as a mechanism to guard against predation (Boos et al 1989, Lanctot et al 1995, or as part of a strategy to search out better brooding territories (Mehl et al 2007).…”