Seven Eggs of the Robin in One 

 Nest. 



On July 5, 1889, seven eggs of the Eobin 

 {Merula migmtoHa) were found in one nest in 

 Montgomery County, Penn. Tlie bird was 

 sitting, and all seven of the eggs were equally 

 incubated. Four of them are smaller than the 

 normal size, and of a darker color than usual, 

 while the other tliree are like ordinary eggs of 

 this bird. The difference is so perceptible 

 that they can be readily separated, and would 

 seem to indicate that two birds had laid in the 

 same nest. 



A very odd runt set of three eggs of the 

 Robin were also taken in the same locality 

 on May 10, 1889. They were fresh, and the 

 parent bird was sitting on the nest. Singu- 

 larly enough they contained yolks, for their 

 size is so diminutive that I did not expect to 

 find any in them. They measure: .78x.6.5; 

 .80x.(i7; .83x.(ii). ./. />. 



O.&O. XIV. Nov. 1889 p.l7£ 



/ The food supply, as Mr. Hoxie suggests, cer- 

 tainly governs, to a great extent, the number 

 of eggs in the clutch. The years from 1880 to 

 1885 were unusually wet years and consequent- 

 ly food was abundant. During these years sets 

 of five of Kobin, (Mertiln migmtoria) and seven 

 of Bluebird, (Sialia sialis) were not uncommon, 

 and in the nests of a great many species whose 

 nest complement is usually four, as the Chat 

 (Icteria virens) , Kingbird {Tyrannus aarolinen- 



sis), Maryland Yellow-throat (Ge( 

 chas) and many others, five eggs were found, 

 while the last year or two has been very dry 

 and it has been difHeult to secure even common 

 sets. 



The nest complement varies also with the 

 time of year. One would hardly expect as 

 large a set of the earlier breeders in July as in 

 April or May. 



Thus it appears that a work which should be 

 the standard for the whole field, must be com- 

 prehensive enough to include in its sweep the 

 utmost f rontiei s of oology. Such works I trust 



will no^K>?j"g£ff 1887 p. /^f 



Robin , (Merula Migratoria). .May 37th, took 

 a set of six Robin's eggs, an unusual number. 



O.&O. XI. Jan, 1886. p. y 



0.&0.^i'5«iifW^#2''«'''"''")- May 271h, took 

 a set of six Robin's eggs, an unusual nunibei'. 



Then again an individual peculiarity is some- 

 times noticed. I remember a Robiu { Mernlq , 

 mufralorUi) up in Massachusetts that raised 

 three broods a year for many seasons in the 

 same orchard. Three eggs were all she ever 

 hiid, and the third brood was only two. At 

 last came the inevitable cat, or she might have 

 been going on in the same course until today. 



The rule seems to me to be that the more 

 robust the bird the larger the clutch. When 

 the food supply is abundant and regular we 

 naturally look for the highest number of eggs 

 in a set, and mce versa. j 

 This, I think, is a more plausable explanation | 

 of the fact than another, which one of my 

 friends suggests. He surmises that large 

 clutches are laid lor the purpose of keeping up 



the standard number of a species in cases 



where they are exposed to extreme vicissitudes 



of some sort, lie iustancos some species whose 



nests arc made on the ground, and whose eggs 



are peculiarly exposed to depredation. It 



seems to me that this is merely a case of the 



survival of the fittest, and that if, in past ages, 



an allied species had laid small clutches, they 



have now become extinct. 



C^.^- ^. X//- /f^i^/-- y 



Editor of O. & O. : 



In iSTovember number of O. &. O. Clyde L. 

 Keller asks if any one ever took tw-enty-four 

 eggs from the nest of one bird in a season. 



1 took twenty-seven eggs and seven nests 

 from one pair of robins the last season. The 

 robins commenced building about April 10th, 

 in an old hay barn on top of a brace. She 

 worked about two weeks, but the material 

 would not stay, when I nailed a block on the 

 brace to hold the nest, which the birds fin- 

 ished, and 1 took No. 1 May 1, 1890; four 

 eggs, fresh. No. 2, May 15th, four eggs, 

 incubation two days, nest same place as No. 

 1. No. 3, May 27th, four eggs, incubation 

 throe days, nest in a binder TOO feet from the 



barn. No. 4, June 5th, four eggs, incubation 

 two days, nest in same place as No. 1. No. 5, 

 June 14th, four eggs, incubation one day, 

 nest in an apple tree fifty feet from the barn. 

 No. 0, June 26th, four eggs, incubation three 

 I days, nest in poplar ten feet from my museum. 

 jNo. 7, July 6th, three eggs, incubation two 

 days, nest same place as No. 1. Nests built 

 of liay, wool, rags, strings and a few feathers. 

 I have all the nests and eggs. Delos Hatch. 

 O.akfleld, Wis. 



ij^jj.SV I, April. 189J. P, 6V- 



