Extreme offspring ornamentation in American coots is favored by selection within families, not benefits to conspecific brood parasites

Offspring ornamentation typically occurs in taxa with parental care, suggesting that selection arising from social interactions between parents and offspring may underlie signal evolution. American coot babies are among the most ornamented offspring found in nature, sporting vividly orange-red natal plumage, a bright red beak, and other red parts around the face and pate. Previous plumage manipulation experiments showed that ornamented plumage is favored by strong parental choice for chicks with more extreme ornamentation but left unresolved the question as to why parents show the preference. Here we explore natural patterns of variation in coot chick plumage color, both within and between families, to understand the context of parental preference and to determine whose fitness interests are served by the ornamentation. Conspecific brood parasitism is common in coots and brood parasitic chicks could manipulate hosts by tapping into parental choice for ornamented chicks. However, counter to expectation, parasitic chicks were duller (less red) than nonparasitic chicks. This pattern is explained by color variation within families: Chick coloration increases with position in the egg-laying order, but parasitic eggs are usually the first eggs a female lays. Maternal effects influence chick coloration, but coot females do not use this mechanism to benefit the chicks they lay as parasites. However, within families, chick coloration predicts whether chicks become “favorites” when parents begin control over food distribution, implicating a role for the chick ornamentation in the parental life-history strategy, perhaps as a reliable signal of a chick’s size or age. (Includes Supporting information.

Extreme offspring ornamentation in American coots is favored by selection within families, not benefits to conspecific brood parasites

Offspring ornamentation typically occurs in taxa with parental care, suggesting that selection arising from social interactions between parents and offspring may underlie signal evolution. American coot babies are among the most ornamented offspring found in nature, sporting vividly orange-red natal plumage, a bright red beak, and other red parts around the face and pate. Previous plumage manipulation experiments showed that ornamented plumage is favored by strong parental choice for chicks with more extreme ornamentation but left unresolved the question as to why parents show the preference. Here we explore natural patterns of variation in coot chick plumage color, both within and between families, to understand the context of parental preference and to determine whose fitness interests are served by the ornamentation. Conspecific brood parasitism is common in coots and brood parasitic chicks could manipulate hosts by tapping into parental choice for ornamented chicks. However, counter to expectation, parasitic chicks were duller (less red) than nonparasitic chicks. This pattern is explained by color variation within families: Chick coloration increases with position in the egg-laying order, but parasitic eggs are usually the first eggs a female lays. Maternal effects influence chick coloration, but coot females do not use this mechanism to benefit the chicks they lay as parasites. However, within families, chick coloration predicts whether chicks become “favorites” when parents begin control over food distribution, implicating a role for the chick ornamentation in the parental life-history strategy, perhaps as a reliable signal of a chick’s size or age. (Includes Supporting information.

The employability of the physically handicapped in manufacturing organizations in Boston, Massachusetts.

Thesis (M.S.)--Boston Universit

VALUING WILDLIFE MANAGEMENT: A UTAH DEER HERD

Managers of public wildlife resources generally are concerned with enhancing the quality of recreation by increasing wildlife through habitat manipulation. However, current recreation valuation studies have focused upon variables that are inappropriate for use in these management decisions. The economic criterion for these decisions should be the value of a change in the stock of the wildlife population compared to its cost. An estimate of such a value was made for the Oak Creek deer herd in Utah, using a household production function approach in an optimal control framework. The value of an additional deer in the herd was estimated to be approximately $40.00.Resource /Energy Economics and Policy,

Analytical procedure for determining random load acting on a spacecraft due to a primary random load acting on an exterior structure Quarterly report no. 2, 1 Sep. - 30 Nov. 1965

Sound and vibration transmission in OGO SPACECRAFT shroud syste

Case Studies of the Attainment of Insight in Dream Sessions: Replication and Extension

To replicate and extend the Hill, Knox, et al. (2007) case study of a client who attained insight in one session of dream work, the authors examined two additional single-session cases: one in which a client gained insight and another in which a client did not. The observations across all three cases suggest that the two clients who acquired insight had positive attitudes toward dreams; were motivated and involved in session; and were nonresistant, trusting, and affectively present but not overwhelmed. The client who did not gain insight questioned the value of dreams and was resistant, untrusting, andf emotionally overwhelmed. Therapist adherence and competence using the dream model, ability to manage countertransference, and effective use of probes for insight distinguished the therapists whose clients gained insight from the therapist whose client did not

The Centrality of Hart Crane\u27s \u27The Broken Tower\u27

No ONE HAS NOTED the extent to which Hart Crane\u27s The Broken Tower not only contains many of his major ideas and elements of expression but also gives them culminating expression.1 Marius Bewley says of the poem that the statement it makes is more central to Crane\u27s life and his view of poetry than that of any other title in The Collected Poems, 2 but he does not develop the point. Herbert Leibowitz examines some of the recurrent images and clusters of images in Crane\u27s work3 but sees in them no development and hence no climax. To me it seems that the recurrence of imagery in Crane\u27s work is accompanied by a recurrence of the rational implications of the images4 and by sporadic movements toward climactic forms. Such forms vary from those which simply sum up a maximum of the multiple (and often antithetical) meanings for an element of expression to those which are the climax of an irregular chronological development. It seems to me that The Broken Tower contains more of these climactic forms than any other of Crane\u27s works and thus that it, more than any other of his poems, sums up what he had written earlier and prophesies directions his later work might have taken had he lived longer. In trying to demonstrate this assertion, I intend, first, to explicate the poem in detail. Next, I will try to show how each of the four principal elements of expression in the poem-the tower (and bells) God, Christ, and the lady-are used in the rest of Crane\u27s work and the extent to which they find characteristic expression in The Broken Tower. Finally, I intend, by comparing the relationship in The Broken Tower between three of these elements of expression with similar relationships in a key group of other works, to show that there is implied in Crane\u27s work as a whole a pattern of psycho-sexual development which also reaches its climax in The Broken Tower