Criticism of von Schantz and Nilsson's Hypothesis on the Reasons for the Reversed Size Dimorphism in Birds of Prey

Oikos ◽  
1982 ◽  
Vol 38 (3) ◽  
pp. 387
Author(s):  
Y. Yom-Tov ◽  
A. Ar
Keyword(s):  
Birds Of Prey ◽  
Size Dimorphism ◽  
Reversed Size Dimorphism

The Reversed Size Dimorphism in Birds of Prey: A Reply

Oikos ◽  
1982 ◽  
Vol 38 (3) ◽  
pp. 388
Author(s):  
Ingvar N. Nilsson ◽  
Torbjörn von Schantz ◽  
Torbjorn von Schantz
Keyword(s):  
Birds Of Prey ◽  
Size Dimorphism ◽  
Reversed Size Dimorphism

The Reversed Size Dimorphism in Birds of Prey: A New Hypothesis

Oikos ◽  
1981 ◽  
Vol 36 (1) ◽  
pp. 129 ◽  
Author(s):  
Torbjörn von Schantz ◽  
Ingvar N. Nilsson ◽  
Torbjorn von Schantz
Keyword(s):  
Birds Of Prey ◽  
Size Dimorphism ◽  
Reversed Size Dimorphism ◽  
New Hypothesis

Mating Patterns and Reversed Size Dimorphism in Southern Skuas (Stercorarius skua lonnbergi)

The Auk ◽  
2002 ◽  
Vol 119 (3) ◽  
pp. 858-863
Author(s):  
Richard A. Phillips ◽  
Deborah A. Dawson
Keyword(s):  
Size Dimorphism ◽  
Mating Patterns ◽  
Reversed Size Dimorphism

scholarly journals Why female birds of prey are larger than males

2020 ◽  
Vol 129 (3) ◽  
pp. 532-542
Author(s):  
Jonny Schoenjahn ◽  
Chris R Pavey ◽  
Gimme H Walter
Keyword(s):  
Sexual Size Dimorphism ◽  
A Priori ◽  
Nest Defence ◽  
Birds Of Prey ◽  
Causal Process ◽  
Size Dimorphism ◽  
Substantial Body ◽  
Key Factor ◽  
Reversed Sexual Size Dimorphism ◽  
Passionate Debate

Abstract The causes of the reversed sexual size dimorphism (RSD; females larger than males) in birds of prey are subject to a centuries-old, passionate debate. A crucial difficulty is to distinguish whether the postulated benefits derive from the proposed causal process(es) or are incidental. After reviewing the existing literature, we present a methodology that overcomes this difficulty and renders unnecessary any speculative a priori distinctions between evolved function and incidental effects. We can thus justify the following novel version of the well-known nest defence hypothesis as the most likely to explain the phenomenon in all birds of prey that show RSD: if the female predominates in actively defending the eggs and young against predators, then she is the heavier sex, and her relatively greater body mass is adaptive. That is, heavier females are favoured (independently of males) by natural selection. The attractiveness of this hypothesis is that it has the potential to explain the phenomenon in all raptors exhibiting RSD, can deal with the exceptional cases in this group, explains the direction of the dimorphism, focuses on a key factor in the reproductive success of most raptors, is parsimonious, i.e. does not require supporting hypotheses, and is supported by a substantial body of evidence.

Reversed Size Dimorphism in Raptors: Evidence for How It Evolved

Oikos ◽  
1988 ◽  
Vol 52 (1) ◽  
pp. 129 ◽  
Author(s):  
John M. Pleasants
Keyword(s):  
Size Dimorphism ◽  
Reversed Size Dimorphism
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