Andrea Erichsen | University of California, Davis (original) (raw)

Papers by Andrea Erichsen

Research paper thumbnail of The white-tailed kite: GIS analysis of habitat selection in the Sacramento Valley, California with implications for conservation of wildlife in agricultural landscapes

Journal of Raptor Research, 1994

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Research paper thumbnail of White-tailed Kite movement and nesting patterns in an agricultural landscape

Raptors in human …, 1996

... Proc. Hawk Migration Confer-ence IV: 313—324. Hawk Migration Association of North America.DAN... more ... Proc. Hawk Migration Confer-ence IV: 313—324. Hawk Migration Association of North America.DANIEL, WW 1990. Applied non-parametric statistics. ... Amer. Birds 34: 682-690. RISEBROUGH, RW, RW SCHLORFF, PH BLOOM AND EE LITTRELL. 1989. ...

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Research paper thumbnail of Oral Estrogen Masculinizes Female Zebra Finch Song System

Hormones and Behavior, 2002

It is well established that parenteral treatment of female zebra finch chicks with estradiol masc... more It is well established that parenteral treatment of female zebra finch chicks with estradiol masculinizes their song control nuclei and that as adults they are capable of song. Concern over the widespread use of putative environmental estrogens caused us to ask whether oral exposure to estrogens (a natural route of exposure) could produce similar effects. We dosed chicks orally with estradiol benzoate (EB; 1, 10, 100, and 1000 nmol/g of body mass per day, days 5–11 posthatch), the non-ionic surfactant octylphenol (100 and 1000 nmol/g), or the pesticides methoxychlor (100 and 1000 nmol/g) and dicofol (100 nmol/g) and measured their song control nuclei as adults. EB treatment produced increases in song nuclei comparable to that induced by parenteral administration of estrogens. This is the first study of which we are aware to use an oral route of administration, which simulates the natural process of parent birds feeding their nestlings. We conclude that oral exposure to estradiol alters song control nuclei and we report in a related paper (Millam et al., 2001) that such exposure severely disrupts reproductive performance. Although we detected no influence of xenobiotics on induction of song control nuclei the possibility remains that oral exposure to xenoestrogens in high enough doses could affect development.

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Research paper thumbnail of Posthatch Oral Estrogen Exposure Impairs Adult Reproductive Performance of Zebra Finch in a Sex-Specific Manner

Hormones and Behavior, 2001

We determined whether short-term, posthatch oral exposure to estradiol benzoate (EB) or the indus... more We determined whether short-term, posthatch oral exposure to estradiol benzoate (EB) or the industrial surfactant octylphenol (OP) could impair the reproductive performance of zebra finches. If so, naturally occurring phytoestrogens and xenoestrogens might influence reproduction in wild populations. Chicks were given oral administration of 10 or 100 nmol EB per gram of body mass (earlier work showed the latter to be the minimum oral dose required to maximally masculinize female song nuclei) or an equimolar amount of OP daily from 5 through 11 days of age. Canola oil was used as a vehicle and control. Reproductive testing was done either in individual pair cages or in communal cages that permitted self-selection of mates, N = 10 pairs per group. Pairs consisted of EB-treated males and females, EB-treated males paired with canola-treated females, vice versa, and canola-treated males and females. Posthatch EB treatment produced sex-specific impairments in reproduction that, in some instances, were additive when both sexes were treated. Egg production was reduced and egg breakage was increased in 100 nmol/g EB-treated male and female pairs. The incidence of missing eggs was increased in 10 nmol/g EB-treated male and female pairs. Candled fertility was reduced in both groups containing 100 nmol/g EB-treated males. The number of hatched chicks was severely reduced in all EB-treated groups. No adverse effects of OP treatment were detected. These significant treatment effects (all P < 0.05) show that posthatch EB treatment profoundly disrupts the reproductive performance of zebra finches, suggesting that exposure to estrogens in the wild could impair the reproductive performance of wild populations.

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Research paper thumbnail of The white-tailed kite: GIS analysis of habitat selection in the Sacramento Valley, California with implications for conservation of wildlife in agricultural landscapes

Journal of Raptor Research, 1994

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Research paper thumbnail of White-tailed Kite movement and nesting patterns in an agricultural landscape

Raptors in human …, 1996

... Proc. Hawk Migration Confer-ence IV: 313—324. Hawk Migration Association of North America.DAN... more ... Proc. Hawk Migration Confer-ence IV: 313—324. Hawk Migration Association of North America.DANIEL, WW 1990. Applied non-parametric statistics. ... Amer. Birds 34: 682-690. RISEBROUGH, RW, RW SCHLORFF, PH BLOOM AND EE LITTRELL. 1989. ...

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Research paper thumbnail of Oral Estrogen Masculinizes Female Zebra Finch Song System

Hormones and Behavior, 2002

It is well established that parenteral treatment of female zebra finch chicks with estradiol masc... more It is well established that parenteral treatment of female zebra finch chicks with estradiol masculinizes their song control nuclei and that as adults they are capable of song. Concern over the widespread use of putative environmental estrogens caused us to ask whether oral exposure to estrogens (a natural route of exposure) could produce similar effects. We dosed chicks orally with estradiol benzoate (EB; 1, 10, 100, and 1000 nmol/g of body mass per day, days 5–11 posthatch), the non-ionic surfactant octylphenol (100 and 1000 nmol/g), or the pesticides methoxychlor (100 and 1000 nmol/g) and dicofol (100 nmol/g) and measured their song control nuclei as adults. EB treatment produced increases in song nuclei comparable to that induced by parenteral administration of estrogens. This is the first study of which we are aware to use an oral route of administration, which simulates the natural process of parent birds feeding their nestlings. We conclude that oral exposure to estradiol alters song control nuclei and we report in a related paper (Millam et al., 2001) that such exposure severely disrupts reproductive performance. Although we detected no influence of xenobiotics on induction of song control nuclei the possibility remains that oral exposure to xenoestrogens in high enough doses could affect development.

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Research paper thumbnail of Posthatch Oral Estrogen Exposure Impairs Adult Reproductive Performance of Zebra Finch in a Sex-Specific Manner

Hormones and Behavior, 2001

We determined whether short-term, posthatch oral exposure to estradiol benzoate (EB) or the indus... more We determined whether short-term, posthatch oral exposure to estradiol benzoate (EB) or the industrial surfactant octylphenol (OP) could impair the reproductive performance of zebra finches. If so, naturally occurring phytoestrogens and xenoestrogens might influence reproduction in wild populations. Chicks were given oral administration of 10 or 100 nmol EB per gram of body mass (earlier work showed the latter to be the minimum oral dose required to maximally masculinize female song nuclei) or an equimolar amount of OP daily from 5 through 11 days of age. Canola oil was used as a vehicle and control. Reproductive testing was done either in individual pair cages or in communal cages that permitted self-selection of mates, N = 10 pairs per group. Pairs consisted of EB-treated males and females, EB-treated males paired with canola-treated females, vice versa, and canola-treated males and females. Posthatch EB treatment produced sex-specific impairments in reproduction that, in some instances, were additive when both sexes were treated. Egg production was reduced and egg breakage was increased in 100 nmol/g EB-treated male and female pairs. The incidence of missing eggs was increased in 10 nmol/g EB-treated male and female pairs. Candled fertility was reduced in both groups containing 100 nmol/g EB-treated males. The number of hatched chicks was severely reduced in all EB-treated groups. No adverse effects of OP treatment were detected. These significant treatment effects (all P < 0.05) show that posthatch EB treatment profoundly disrupts the reproductive performance of zebra finches, suggesting that exposure to estrogens in the wild could impair the reproductive performance of wild populations.

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