18 



Fredholm (18) states that the common Trinidad garden toad 

 gorges itself upon the mole cricket. This is a South American species 

 and maintains itself only where the mongoose is kept down. There 

 are at least two species of Texas toads, nocturnal in habit and gen- 

 erally insectivorous, which might upon introduction reduce the 

 numbers of the Porto Rican mole cricket (48) were it not for the 

 mongoose which now overruns the island. 



Birds. The most efficient enemies of the changa are to be found 

 among the native birds. The comparative value of the various 

 species has been determined by Wetmore (53), from whose publica- 

 tion the following notes are taken : 



The blackbird (Holoqulscalus brachypterus) , popularly considered one of 

 the greatest enemies of " la changa," in reality destroys but few. * * * 

 Other species, however, make up for the blackbird's shortcomings, and among 

 them the despised martinete (Butorides virescens cubanus), ridiculed for its 

 ungainliness, ranks foremost. Standing watchfully, with head drawn in, 

 among the short growth of the young cane fields, or walking with lengthened 

 stride along the border of lowland pools, it spies and avidly swallows both 

 adults and young of the mole cricket. The species at present known to aid in 

 suppressing this pest number 21, and following is a list of them arranged 

 somewhat in order of importance (figures following the name indicate the 

 percentage formed by the mole cricket in the total bulk of the food) : 



Bu-<k\(memies of mole cricket. 

 [From Wetmore.] 



Per cent. 

 Martinete (Butorides virescens cu- 



banus) 54. 33 



Falc6n (Falco sparverius loquacula)- 28.69 

 Playero (Oxyechus vociferus ru- 



bidus) 34.42 



Putilla (Actitis macularia) 10.78 



Garza (Florida caerulea coerulescena) _ 7. 23 



Judfo (Cro1f,phaga ani) 5.69 



Ruisenor (Himus polyglottos or- 



pheus) 3. 62 



Cle"rigo (Tolmarchus taylori) 3.04 



Pitirre (Tyrannus dominicensis do- 

 minicensis) 2. 36 



Juf (Myiarchutt antillarum) 1.27 



Garz6n bianco (Herodias egretta) 1.00 



Julian chivf (Vireo latimeri) .90 



Per cent. 

 Zorzal (Mimocichla ardosiacea porto- 



ricensis) _______________________ 0. 86 



Mticaro (Gymnasia nudipes nudipes) _ 



Canario de manglar (Dendroica pe- 



techia lartholemica) ____________ 



Gorri6n (Coturniculus savannarum 

 intricatus) ____________________ 



Mozambique (Holoquiscalus brachyp- 



Calandra (Icterus portoricensis) ___ 



Pajaro bobo (Coccyzus minor nesi- 



otes) __________________________ 



Zorzal negro (Margarops fuscatus 

 fuscatus) ______________________ 



Becacina (Gallinago delicata), one 

 bird only examined _____________ 



. 60 

 .25 

 . 25 



. 21 

 .21 



. 21 

 . 16 



The Cuban green heron [martinete] is one of the commonest birds in Porto 

 Rico and is distributed all through the coastal plain. * * * Clumps of 

 bamboos along streams were favorite perches. To these growths numbers 

 retired to escape the burning heat of the midday sun, and in many localities 

 they were used as nesting sites. Most of these birds, however, still nest in 

 the mangroves and swampy growths bordering lagoons and lowland streams. 

 * * * Three stomachs [of this species] taken in January and two in August 

 contain little else [besides bodies of the changa], while the smallest propor- 

 tion 13 per cent occurs in the month of June. 



