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Breeding Season Ecology and Demography of Lesser Scaup (Aythya affinis) at Red Rock Lakes National Wildlife Refuge.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Breeding Season Ecology and Demography of Lesser Scaup (Aythya affinis) at Red Rock Lakes National Wildlife Refuge./
Author:	Warren, Jeffrey M.
Description:	1 online resource (168 pages)
Notes:	Source: Dissertation Abstracts International, Volume: 79-07(E), Section: B.
Contained By:	Dissertation Abstracts International79-07B(E).
Subject:	Ecology. -
Online resource:	click for full text (PQDT)
ISBN:	9780355623406

Breeding Season Ecology and Demography of Lesser Scaup (Aythya affinis) at Red Rock Lakes National Wildlife Refuge.
Warren, Jeffrey M.

Breeding Season Ecology and Demography of Lesser Scaup (Aythya affinis) at Red Rock Lakes National Wildlife Refuge. - 1 online resource (168 pages)

Source: Dissertation Abstracts International, Volume: 79-07(E), Section: B.

Thesis (Ph.D.)

Includes bibliographical references

It is hypothesized that individuals make reproductive decisions based on current assessments of their physiological condition and environmental conditions. For female lesser scaup (Aythya affinis), breeding occurs after an energetically costly spring migration. Increasing fat reserves (i.e., 'body condition') prior to breeding allows a female to produce a larger clutch of eggs, but time spent gaining body condition is costly in terms of time allowed to raise ducklings before freezing conditions in the fall. In Chapter 2 I explored rate of pre-breeding body condition gain in female lesser scaup, and how that rate influenced clutch size. Spring phenology, measured by proxy as water temperature, and water depth strongly influenced the rate at which females increased body condition. Early springs with low water levels led to greater rates of body condition gain in female scaup. The higher the rate of body condition gain, the larger the clutch of eggs females produced. Body condition is also an important determinant of breeding in female ducks; females in poor body condition are more likely to forego breeding. I explored how body condition, wetland conditions, and prior experience influence a female's decision to breed in Chapter 3. Body condition was a strong determinant of when a female bred, with females in good body condition breeding earlier than females in poorer body condition. Habitat conditions were also important, with drought reducing the proportion of breeding lesser scaup females. In Chapter 4 I examined survival costs of reproduction in female scaup. Nesting exposes females to increased predation risk (a concurrent survival cost), and reduced post-breeding body condition may reduce female survival the subsequent non-breeding season (a serial, or 'downstream', survival cost). Female survival during breeding and non-breeding seasons was most correlated with breeding season water level on the study site, but in opposite directions. Breeding season survival increased with increasing water levels, while non-breeding season survival declined. High water levels on the study site increased the availability of presumably high-security nesting habitat, and also increased female reproductive effort. The former increased breeding season survival, while the latter reduced non-breeding season survival.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2018

Mode of access: World Wide Web

ISBN: 9780355623406Subjects--Topical Terms:

575279
Ecology.
Index Terms--Genre/Form:

554714
Electronic books.

Breeding Season Ecology and Demography of Lesser Scaup (Aythya affinis) at Red Rock Lakes National Wildlife Refuge.
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245 1 0 $a Breeding Season Ecology and Demography of Lesser Scaup (Aythya affinis) at Red Rock Lakes National Wildlife Refuge.
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300 $a 1 online resource (168 pages)
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500 $a Source: Dissertation Abstracts International, Volume: 79-07(E), Section: B.
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504 $a Includes bibliographical references
520 $a It is hypothesized that individuals make reproductive decisions based on current assessments of their physiological condition and environmental conditions. For female lesser scaup (Aythya affinis), breeding occurs after an energetically costly spring migration. Increasing fat reserves (i.e., 'body condition') prior to breeding allows a female to produce a larger clutch of eggs, but time spent gaining body condition is costly in terms of time allowed to raise ducklings before freezing conditions in the fall. In Chapter 2 I explored rate of pre-breeding body condition gain in female lesser scaup, and how that rate influenced clutch size. Spring phenology, measured by proxy as water temperature, and water depth strongly influenced the rate at which females increased body condition. Early springs with low water levels led to greater rates of body condition gain in female scaup. The higher the rate of body condition gain, the larger the clutch of eggs females produced. Body condition is also an important determinant of breeding in female ducks; females in poor body condition are more likely to forego breeding. I explored how body condition, wetland conditions, and prior experience influence a female's decision to breed in Chapter 3. Body condition was a strong determinant of when a female bred, with females in good body condition breeding earlier than females in poorer body condition. Habitat conditions were also important, with drought reducing the proportion of breeding lesser scaup females. In Chapter 4 I examined survival costs of reproduction in female scaup. Nesting exposes females to increased predation risk (a concurrent survival cost), and reduced post-breeding body condition may reduce female survival the subsequent non-breeding season (a serial, or 'downstream', survival cost). Female survival during breeding and non-breeding seasons was most correlated with breeding season water level on the study site, but in opposite directions. Breeding season survival increased with increasing water levels, while non-breeding season survival declined. High water levels on the study site increased the availability of presumably high-security nesting habitat, and also increased female reproductive effort. The former increased breeding season survival, while the latter reduced non-breeding season survival.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2018
538 $a Mode of access: World Wide Web
650 4 $a Ecology. $3 575279
650 4 $a Wildlife conservation. $3 654486
655 7 $a Electronic books. $2 local $3 554714
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690 $a 0284
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a Utah State University. $b Wildland Resources. $3 1182574
773 0 $t Dissertation Abstracts International $g 79-07B(E).
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10744930 $z click for full text (PQDT)