Article Abstract:
The diel and cyclical patterns in nesting behavior of Mexican spotted owls (Strix occidentalis lucida) were studied. About 2,655 hours of behavioral information were collected by video surveillance on 19 pairs of owls between Apr 25 and Jul 26, 1996. The results showed that prey deliveries increased as the nesting season progressed, while nest attendance peaked during the incubation phase and decreased as the nesting season progressed. The birds showed a marked cyclical change in their activity patterns in response to ecological factors.
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Article Abstract:
The time-budgets in two colonies of common murres (Uria aalge) at breeding sites in lower Cook Inlet, AK, were examined. The results showed that catches of forage fish in nets and relative biomass were larger around an increasing colony than a declining colony over a 25-yr period. Chick feeding rates, chick growth rates and productivity did not differ between the two colonies. It was shown the attendance time-budgets is a more sensitive index of food availability than other breeding parameters.
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Article Abstract:
Parent-offspring behaviors in a failing colony of Black-legged Kittiwakes on Middleton Island, AK, were examined. A strong correlation was found between chick feeding and begging rates and overall breeding performance, but no correlation was found between the former and adult time allocation patterns, measured in terms of foraging trips and nest attendance. Recurrent breeding failure in the colony was attributed to food shortage.
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