Food Habits of the Thrushes of the United States Part 3

The ants destroyed--12.46 per cent of the food--keep up the reputation of thrushes as ant eaters. They were taken constantly every month, with the greatest number from May to September; a falling off in July is partly accounted for by the fact that more fruit is taken in that month. Other Hymenoptera (bees and wasps) were eaten to the extent of 5.41 per cent, a surprising amount for a bird that feeds so largely upon the ground, as these insects are usually of fleet wing and live in sunshine and open air.

Caterpillars, eaten in every month and mostly in goodly quant.i.ties, appear to be a favorite food of the hermit thrush. December is the month of least consumption (2.75 per cent), while the most were eaten in June (17.08 per cent). The average for the year is 9.54 per cent.

Hemiptera (bugs) seem to be eaten whenever found, as they appear in the food of every month, but rather irregularly and not in large quant.i.ties. The greatest consumption was in June (9.17 per cent), but July, September, and December show the least (less than 1 per cent).

The total for the year is 3.63 per cent. Of the six families represented, the Pentatomidae, or stink bugs, predominate. These highly flavored insects are eaten by most insectivorous birds often, but usually in small quant.i.ties.

Diptera (flies) comprise 3.02 per cent of the food of the hermit thrush. The record shows, however, that nearly all of them are either crane flies (Tipulidae) and their eggs and larvae, or March flies (_Bibio_) and their larvae. Over 150 of the latter were found in one stomach. Both of these families of flies lay their eggs in the ground, which accounts for their consumption by ground-feeding birds.

Orthoptera (gra.s.shoppers and crickets) are eaten by the hermit thrush to the extent of 6.32 per cent of its food. While this figure is not remarkable, it is the highest for any of the genus. These birds are fond of dark moist nooks among trees and bushes and do not feed extensively in those dry sunshiny places so much frequented by gra.s.shoppers. A close inspection of the food record shows that the Orthoptera eaten by the thrushes are mostly crickets, which live in shadier and moister places than those where gra.s.shoppers abound. A few miscellaneous insects (0.27 per cent) close the insect account.

Spiders and myriapods (7.47 per cent) seem to const.i.tute a very acceptable article of diet, as they amount to a considerable percentage in nearly every month, and in May rise to 20.79 per cent. A few miscellaneous animals, as sowbugs, snails, and angleworms, make up the balance of the animal food (1.26 per cent).

Following is a list of insects so far as identified and the number of stomachs in which found:

HYMENOPTERA.

_Tiphia inornata_ 2

COLEOPTERA.

_Elaphrus_ sp 1 _Notiophilus semistriatus_ 1 _Scarites subterraneus_ 1 _Dyschirius pumilis_ 1 _Pterostichus patruelis_ 1 _Pterostichus_ sp 1 _Amara_ sp 1 _Chlaenius pennsylvanicus_ 2 _Stenolophus_ sp 1 _Anisodactylus agilis_ 1 _Tropisternus limbalis_ 2 _Hydrocharis obtusatus_ 1 _Sphaeridium lecontei_ 1 _Ptomaphagus consobrinus_ 1 _Anisotoma valida_ 1 _Megilla maculata_ 1 _Anatis 15-maculata_ 1 _Psyllobora taedata_ 1 _Brachycantha ursina_ 1 _Endomychus biguttatus_ 1 _Cryptophagus_ sp 1 _Hister marginicollis_ 1 _Hister america.n.u.s_ 1 _Saprinus fimbriatus_ 1 _Carpophilus hemipterus_ 1 _Perthalycra murrayi_ 1 _Ips quadriguttatus_ 3 _Cytilus sericeus_ 2 _Cytilus_ sp 1 _Byrrhus kirbyi_ 1 _Byrrhus cyclophorus_ 1 _Cryptohypnus bicolor_ 2 _Drasterius dorsalis_ 1 _Dolopius lateralis_ 1 _Melanotus_ sp 2 _Podabrus tomentosus_ 1 _Canthon_ sp 1 _Onthophagus tuberculifrons_ 1 _Onthophagus_ sp 3 _aegialia lacustris_ 1 _Rhyssemus scaber_ 1 _Ataenius abditus_ 1 _Ataenius cognatus_ 1 _Ataenius_ sp 1 _Aphodius fimetarius_ 11 _Aphodius granarius_ 1 _Aphodius rugifrons_ 1 _Aphodius inquinatus_ 9 _Aphodius pardalis_ 1 _Aphodius prodromus_ 4 _Aphodius cra.s.siusculus_ 1 _Aphodius_ sp 11 _Geotrupes semipunctata_ 1 _Dichelonycha_ sp 1 _Lachnosterna_ sp 17 _Chrysomela pulchra_ 3 _Lema nigrovittata_ 1 _Chlamys plicata_ 1 _Myochrous denticollis_ 2 _Xanthonia 10-notata_ 1 _Calligrapha scalaris_ 1 _Leptinotarsa decemlineata_ 1 _Phaedon viridis_ 1 _Diabrotica vittata_ 1 _Odontota rubra_ 1 _Odontota_ sp 1 _Haltica torquata_ 1 _Crepidodera helxines_ 1 _Syneta ferruginea_ 1 _Systena elongata_ 1 _Chaetocnema pulicaria_ 1 _Psylliodes punctulata_ 1 _Chelymorpha cribraria_ 1 _Opatrinus notus_ 1 _Opatrinus aciculatus_ 1 _Blapstinus metallicus_ 1 _Blapstinus rufipes_ 1 _Salpingus virescens_ 1 _Anthicus p.u.b.escens_ 1 _Notoxus monodon_ 1 _Notoxus denudatum_ 1 _Notoxus_ sp 1 _Attelabus rhois_ 1 _Rhigopsis effracta_ 1 _Cercopeus chrysorrhus_ 4 _Pandetetejus hilaris_ 1 _Barypithes pellucidus_ 1 _Sitones hispidulus_ 4 _Sitones flavescens_ 1 _Trichalophus alternatus_ 1 _Apion_ sp 1 _Listronotus latiusculus_ 1 _Listronotus inaequalipennis_ 1 _Listronotus_ sp 1 _Macrops_ sp 2 _Smicronyx corniculatus_ 1 _Trachodes ptinoides_ 1 _Conotrachelus nenuphar_ 2 _Conotrachelus posticatus_ 5 _Conotrachelus erinaceus_ 1 _Rhinoncus pyrrhopus_ 1 _Onychobaris insidiosus_ 1 _Balaninus nasicus_ 1 _Balaninus_ sp 1 _Sphenophorus parvulus_ 1 _Sphenophorus_ sp 1 _Dendroctonus terebrans_ 1

HEMIPTERA.

_Podops cinctipes_ 1 _Nezara hilaris_ 6 _Arhaphe cicindeloides_ 1 _Corimelaena denudata_ 1 _Myodocha serripes_ 2

ORTHOPTERA.

_Amblycorypha rotundifolia_ 1 _canthus niveus_ 1

_Vegetable food._--The vegetable diet of the hermit thrush consists largely of fruit, as with most birds of this group. As might be expected of a bird of such retiring habits, but little of the fruit eaten can be cla.s.sed as cultivated. In September 5.45 per cent was so considered, but in most months the quant.i.ty was small, and in March, April, and May was completely wanting. The total for the year as found in 17 stomachs is 1.20 per cent. One stomach contained strawberries, one grapes, one figs, one currants, two apples, and the rest _Rubus_ fruit, i. e., blackberries or raspberries. These last as well as the strawberries were probably wild. Of the wild fruit (26.19 per cent) 46 species were identified with a reasonable degree of certainty in 243 stomachs. A few seeds, ground-up vegetable matter not further identified, and rubbish make up the rest of the vegetable food (8.10 per cent). Among the seeds were some of the various species of poisonous _Rhus_. These were found in 18 stomachs, mostly from California. The dissemination of these seeds is unfortunate from the standpoint of husbandry, but many birds engage in it, as the waxy coating of the seeds is nutritious, especially in winter, when fruit and insects are not easily obtainable.

Following is a list of the components of the vegetable food so far as identified, and the number of stomachs in which found:

Cedar berries (_Juniperus virginiana_) 2 False Solomon's seal (_Smilacina racemosa_) 4 False spikenard (_Smilacina_ sp.) 1 Greenbrier (_Smilax walteri_) 2 Cat brier (_Smilax bona-nox_) 2 Laurel-leaved greenbrier (_Smilax laurifolia_) 1 Other greenbriers (_Smilax_ sp.) 11 Wax myrtle (_Myrica cerifera_) 1 Bayberries (_Myrica carolinensis_) 7 Chinquapin (_Castanea pumila_) 1 Western hackberries (_Celtis occidentalis_) 5 Other hackberries (_Celtis_ sp.) 3 Figs (_Ficus_ sp.) 1 Mulberries (_Morus_ sp.) 1 Mistletoe berries (_Phoradendron villosum_) 2 Poke berries (_Phytolacca decandra_) 16 Miner's lettuce (_Montia perfoliata_) 1 Sa.s.safras berries (_Sa.s.safras varifolium_) 2 Spice berries (_Benzoin aestivale_) 1 Currants (_Ribes_ sp.) 3 Sweet gum (_Liquidambar styraciflua_) 2 Chokeberries (_Pyrus arbutifolia_) 1 Service berries (_Amelanchier canadensis_) 9 Hawthorn (_Crataegus_ sp.) 1 Strawberries (_Fragaria_ sp.) 1 Blackberries or raspberries (_Rubus_ sp.) 5 Rose haws (_Rosa_ sp.) 1 Wild black cherries (_Prunus scrotina_) 3 Three-seeded mercury (_Acalypha virginica_) 1 Staghorn sumach (_Rhus typhina_) 5 Smooth sumach (_Rhus glabra_) 5 Dwarf sumach (_Rhus copallina_) 7 Poison ivy (_Rhus radicans_) 3 Poison oak (_Rhus diversiloba_) 15 Laurel-leaved sumach (_Rhus laurina_) 2 Other sumachs (_Rhus_ sp.) 12 Pepper berries (_Schinus molle_) 15 American holly (_Ilex opaca_) 9 Black alder (_Ilex verticillata_) 12 Ink berries (_Ilex glabra_) 9 Other hollies (_Ilex_ sp.) 7 Strawberry bush (_Euonymus america.n.u.s_) 1 Roxbury waxwork (_Celastrus scandens_) 1 Supple-Jack (_Berchemia volubilis_) 2 Coffee berries (_Rhamnus californicus_) 1 Woodbine (_Psedera quinquefolia_) 10 Frost grapes (_Vitis cordifolia_) 2 Wild grapes (_Vitis_ sp.) 1 Wild sarsaparilla (_Aralia nudicaulis_) 1 Flowering dogwood (_Cornus florida_) 32 Rough-leaved dogwood (_Cornus asperifolia_) 2 Black gum (_Nyssa sylvatica_) 2 Checkerberry (_Gaultheria proc.u.mbens_) 1 Huckleberries (_Gaylussacia_ sp.) 1 Blueberries (_Vaccinium_ sp.) 12 Black nightshade (_Solanum nigrum_) 4 Bittersweet (_Solanum_ sp.) 4 Goose gra.s.s (_Galium aparine_) 1 Honeysuckle (_Lonicera_ sp.) 2 Indian currant (_Symphoricarpos...o...b..culatus_) 1 Downy arrowwood (_Viburnum p.u.b.escens_) 1 Nanny berries (_Viburnum lentago_) 2 Black elderberries (_Sambucus canadensis_) 4 Red elderberries (_Sambucus p.u.b.ens_) 3 Fruit not further identified 60

In looking over this list one is impressed with the fact that the taste of human beings for fruit differs markedly from that of birds.

For example, _Rhus_ seeds are hard and have little pulp to render them palatable or nutritious. They are usually pa.s.sed through the alimentary ca.n.a.l of birds or regurgitated unharmed, and the slight outer coating alone is digested. In the case of the poisonous species, this outer coating is a white wax or tallow which appears to be very nutritious, for these species are eaten much more extensively than the nonpoisonous ones. The seed itself is rarely broken in the stomach to get any nutriment it may contain. But in spite of these facts _Rhus_ seeds were found in 49 stomachs, while fruits of huckleberries and blueberries, which are delicious to the human taste, were found in only 13 stomachs; and blackberries and raspberries, highly esteemed by man, were found in only 5 stomachs. Next to _Rhus_ the fruit most eaten was the dogwood berry, found in 34 stomachs, yet from a human estimate these berries are distasteful and contain such large seeds that they afford but very little actual food.

_Summary._--The hermit thrush, as it name indicates, is of solitary habits and neither seeks human companionship nor molests cultivated products. It destroys nothing indirectly helpful to man, as beneficial insects, but aids in the destruction of the myriad hosts of insect life which at all times threaten vegetation. While it is not easy to point out any especially useful function of the hermit thrush, it fills its place in the economy of nature, from which it should not be removed.