Filters: Tags: reproductive success (X)8 results (50ms)
Examination of contaminant exposure and reproduction of ospreys (Pandion haliaetus) nesting in Delaware Bay and River in 2015
Reproductive Data for All Nests Monitored; Data for Mayfield Analysis; Eggshell thickness, nestling morphological measurements, nestling plasma stable isotopes, and nestling red blood cell oxidative DNA damage; Egg organochlorine pesticide, total PCB, flame retardants, and PCB toxic equivalent concentrations; Fish capture by osprey; Fish pools and size for contaminant analysis; Fish organochlorine pesticide, total PCB and flame retardants concentrations; Data for estimation of p,p’-DDE and total PCB biomagnification from fish to osprey eggs
In many social sciurids, male territoriality confers significant mating advantages. We evaluated resident male paternity in Gunnison's prairie dogs (Cynomys gunnisoni), a colonial ground-dwelling sciurid, where males and females cooperatively defend territories. Contrary to findings reported for other social sciurids, our results show that territorial resident males do not gain significant reproductive advantages. Resident males sired the majority of offspring from their respective territories only 10.5% of the time. A single non-resident male sired equal or greater number of offspring than any single resident male 71.2% of the time. While adult males were more likely to sire a greater number of offspring, standard...
Effects of late-incubation body mass on reproductive success and survival of canvasbacks and redheads
Reproductive success and contaminant associations in tree swallows (Tachnycineta bicolor) nesting in the U.S. and Binational Great Lakes' Areas of Concern data
During 2010-2014, tree swallow (Tachycineta bicolor) reproductive success was monitored at 68 sites across all 5 Great Lakes, including 58 sites located within Great Lakes Areas of concern (AOCs) and 10 non-AOCs. Sample eggs were collected from tree swallow clutches and analyzed for contaminants including polychlorinated biphenyls (PCBs), dioxin and furans, polybrominated diphenyl ethers, and 34 other organic compounds. Contaminant data were available for 360 of the 1249 clutches monitored. Markov chain multistate modeling was used to assess the importance of 5 ecological and 11 of the dominant contaminants in explaining the pattern of egg and nestling failure rates. Four of 5 ecological variables (female Age, Date...
Although polygyny can potentially increase male reproductive success, the benefits of this strategy could be offset by losses to extra-pair paternity or reduced offspring survival. We developed microsatellite markers to assess the influence of extrapair offspring (EPO) on reproductive success and paternity in monogamous and polygynous pairs of the facultatively polygynous Southwestern Willow Flycatcher (Empidonax traillii extimus). Based on genotypes of 140 offspring from 56 clutches over six years, 14% of nestlings in our study population were extra-pair offspring, with 23% of all successful nests containing at least one EPO. We found that polygynous males produced 2.11 0.35 offspring per season, compared to 1.15...
Polygyny and female breeding failure reduce effective population size in the lekking Gunnison sage-grouse
Populations with small effective sizes are at risk for inbreeding depression and loss of adaptive potential. Variance in reproductive success is one of several factors reducing effective population size (Ne) below the actual population size (N). Here, we investigate the effects of polygynous (skewed) mating and variation in female breeding success on the effective size of a small population of the Gunnison sage-grouse (Centrocercus minimus), a ground nesting bird with a lek mating system. During a two-year field study, we recorded attendance of marked birds at leks, male mating success, the reproductive success of radio-tagged females, and annual survival. We developed simulations to estimate the distribution of...