The unique predatory, caching, and impaling behaviors of shrikes (Laniidae) may provide these unusual passerines with alternative provisioning strategies compared to other songbirds, but few studies have determined the impact these unique behaviors have on provisioning rates. Our objectives were to compare the provisioning behavior of male and female Loggerhead Shrikes (Lanius ludovicianus), and determine how their provisioning behavior was influenced by nestling age. The provisioning behavior of six pairs of Loggerhead Shrikes was videotaped from 15 April to 15 August 2004–2007 in Garrard and Madison counties, Kentucky, USA. For each nest visit by a shrike, the sex of the visiting adult, number of prey items delivered, size of prey, type of prey, and the duration of the nest visit were recorded. Adults made 2169 visits to nests, with males (49%) and females (51%) making similar numbers of visits. Males and females differed in time spent at nests, with males spending less time at nests per visit (mean = 12.0 s, N = 1062) than females (77.0 s, N = 1107). Feeding rates did not differ between the sexes, but feeding rates did increase with nestling age. The size of prey delivered to nestlings also tended to increase with nestling age. Invertebrates comprised 65% of the identified prey items, and cached items made up the remaining 35%. Although many passerine species increase provisioning rates as nestling demand increases, the caching behavior of shrikes may allow adults to reliably increase both feeding rates and prey size as nestling age and demand increase as well as act as buffers when prey availability declines. The caching behavior of shrikes provides them with parental provisioning strategies not available to non-caching songbirds.
YosefR. Loggerhead Shrike (Lanius ludovicianus), version 1.0. In: PooleAFGillFB (eds.). Birds of the world. USA: Cornell Lab of Ornithology; 2020.
2.
KridelbaughAL. An ecological study of Loggerhead Shrikes in central Missouri. MS Thesis. USA: University of Missouri, 1982.
3.
YosefR. Territoriality, nutritional condition, and conservation in Loggerhead Shrikes (Lanius ludovicianus). PhD dissertation. USA: Ohio State University, 1992.
4.
SoobramoneySDownsCTAdamsNJ. Variability in foraging behaviour and prey of the Common Fiscal Shrike (Lanius collaris) along an altitudinal gradient in South Africa. Ostrich2004; 75: 133–140.
5.
SloaneSA. The shrike’s display advertising. Nat Hist1991; 6: 32–39.
6.
YosefRPinshowB. Cache size in shrikes influences female mate choice and reproductive success. Auk1989; 106: 418–421.
7.
TryjanowskiPKargMKKargJ. Diet composition and prey choice by the Red–backed Shrike (Lanius collurio) in western Poland. Belgian J Zool2003; 133: 157–162.
8.
YosefRWhitmanDW. Predator exaptations and defensive adaptations in evolutionary balance: no defense is perfect. Evol Ecol1992; 6: 527–536.
9.
CarlsonA. Central place of food caching: a field experiment with Red-backed Shrike (Lanius collurio). Behav Ecol Sociobiol1985; 16: 317–322.
10.
GolawskiAMrozEGolawskaS. The function of food storing in shrikes: the importance of larders for the condition of females and during inclement weather. Eur Zool. J, 2020; 87: 282–293.
11.
AntczakMHromadaMTryjanowskiP. Spatio-temporal changes in Great Grey Shrike (Lanius excubitor) impaling behaviour: from food caching to communication signs. Ardea2005; 93: 101–107.
12.
BuddenAEWrightJ. Nestling diet, chick growth and breeding success in the Southern Grey Shrike (Lanius meridionalis). Ring2000; 22: 165–172.
13.
OlsonWC. Territory quality, reproductive success and hunting behavior of Loggerhead Shrikes (Lanius ludovicianus). MS Thesis. USA: Eastern Kentucky University, 2006.
14.
PetersonNR. Territory size, habitat use, hunting behavior, and reproductive success of Loggerhead Shrikes in central Kentucky. MS Thesis. USA: Eastern Kentucky University, 2006.
15.
KridelbaughAL. Nesting ecology of the Loggerhead Shrike in central Missouri. Wilson Bull1983; 95: 303–308.
16.
NovakPG. Breeding ecology and status of the Loggerhead Shrike in New York state. MS Thesis. USA: Cornell University, 1989.
PorterDKStrongMAGiezentannerJB, et al. Nest ecology, productivity, and growth of the Loggerhead Shrike on the shortgrass prairie. Southwest Nat1975; 19: 429–436.
19.
MillerAH. A comparison of behavior in certain North American and European shrikes. Condor1937; 39: 119–122.
20.
BentAC. Life histories of North American wagtails, shrikes, vireos, and their allies. U S Natl Mus Bull1950; 197: 182–214.
21.
WemmerC. Impaling behaviour of the Loggerhead Shrike, Lanius ludovicianus. Z Tierpsychol1969; 26: 208–224.
22.
BlumtonAK. Factors affecting Loggerhead Shrike mortality in Virginia. MS Thesis. USA: Virginia Polytech Inst. and State Univ., 1989.
23.
GoodbredCOHolmesRT. Factors affecting food provisioning of nestling Black-throated Blue Warblers. Wilson Bull1996; 108: 467–479.
24.
SAS Institute. SAS, version 9.1.3. USA: SAS Institute, Cary, 2006.
25.
KeynanOYosefR. Temporal changes and sexual differences of impaling behavior in Southern Grey Shrike (Lanius meridionalis). Behav Proc2010; 85: 47–51.
26.
GawlikDEPappJBildsteinKL. Nestling diet and prey-delivery rates of Loggerhead Shrikes (Lanius ludovicianus) in north-central South Carolina. Chat1991; 55: 1–5.
27.
FanLGaoLZhuZ, et al. The Grey-backed Shrike parents adopt brood survival strategy in both the egg and nestling phases. Avian Res2021; 12: 11.
28.
SchaddCARitchisonG. Provisioning of nestlings by male and female Yellow-breasted Chats. Wilson Bull1998; 110: 398–402.
29.
KrystofkovaMExnerováAPorkertJ. Parental foraging strategies and feeding of nestlings in Common Redstart Phoenicurus phoenicurus. Ornis Fennica2006; 83: 49–58.
30.
TarwaterCEBrawnJD. Patterns of brood division and an absence of behavioral plasticity in a Neotropical passerine. Behav Ecol Sociobiol2008; 62: 1441–1452.
31.
DeVriesMSJaworJM. Natural variation in circulating testosterone does not predict nestling provisioning rates in the Northern Cardinal, Cardinalis cardinalis. Anim Behav2013; 85: 957–965.
32.
JohnsonEJBestLB. Factors affecting feeding and brooding of Gray Catbird nestlings. The Auk1982; 99: 148–156.
33.
RitchisonGHawkinsJARitchisonBC. Brooding and provisioning of nestlings by male and female White-eyed Vireos (Vireo griseus). Avian Biol Res2019; 12: 28–32.
34.
HoweHF. Evolutionary aspects of parental care in the common Grackle (Quiscalus quiscula). Evolution1979; 33: 41–51.
35.
BanburaJPerretPBlondelJ, et al. Sex differences in parental care in a Corsican Blue Tit (Parus caeruleus) population. Ardea2001; 89: 517–526.
36.
SanzJJTinbergenJM. Energy expenditure, nestling age, and brood size: an experimental study of parental behaviour in the Great Tit (Parus major). Behav Ecol1999; 10: 598–606.
37.
GowEAStutchburyBJM. Understanding sex differences in parental effort in a migratory songbird: examining a sex-specific trade-off between reproduction and molt. Condor2013; 115: 640–649.
38.
de MoraesPZDinizPMacedoRH. Sex-specific effects of predation risk on parental care in a sexually dichromatic Neotropical songbird. J Avian Biol2020; 51: jav02483.
39.
LifjeldJTGohliJAlbrechtT, et al. Evolution of female promiscuity in Passerides songbirds. BMC Evol Biol2019; 19: 169.
40.
RytkonenSKoivulaKOrellM. Patterns of per-brood and per-offspring provisioning efforts in the Willow Tit (Parus montanus). J Avian Biol1996; 27: 21–30.
41.
MitrusCMitrusJMagdalenaS. Sex differences in the rate of food provisioning to nestling Red-breasted Flycatchers (Ficedula parva). Ann Zool Fennici2010; 47: 144–148.
42.
DarrahAJRiperCIII. Brood provisioning rates and fledgling behavior of Cordilleran Flycatchers in southwestern Colorado. J Field Ornithol2021; 92: 30–42.
43.
RicklefsRE. Patterns of growth in birds. Ibis1968a; 110: 320–325.
44.
RicklefsRE. Weight recession in nestling birds. Auk1968b; 85: 30–35.
45.
MartinsTLF. Fledging in the Common Swift, Apus apus: weight-watching with a difference. Anim Behav1997; 54: 99–108.
46.
BreitwischRMerrittPGWhitesidesGH. Parental investment by the Northern Mockingbird: male and female roles in feeding nestlings. Auk1986; 103: 152–159.
47.
GrundelR. Determinants of nestling feeding rates and parental investment in the Mountain Chickadee. Condor1987; 89: 319–328.
48.
PinkowskiBC. Feeding of nestling and fledgling Eastern Bluebirds. Wilson Bull1978; 90: 84–98.
49.
ChastelOKerstenM. Brood size and body condition in the House Sparrow (Passer domesticus): the influence of brooding behaviour. Ibis2002; 144: 284–292.
50.
CadeT. Shrikes as predators. Proc West. Found Vert Zool1995; 6: 1–5.
