2 50] GeneralNotes j. Field Ornithol. Spring 1984

Red-headedWoodpeckers Defend Occupied American Nest.--Near Co- lumbia,Missouri wc found a large squarishhole 24 m aboveground level in a large pine power-pole,probably excavated by a PilcatcdWoodpecker (Dryocopus pileatus). The hole wasjust belowthe crossarm and had bccnused 3 successiveyears by a pair of nesting AmericanKcstrcls (Falco sparverius). In 1982, the kestrelslaid a clutchbetween 29 March and 3 April. These eggshatched during the last 3 daysof April. On 7 May at 09:45 the femalekcstrc] was sccn at the nestwith a (Microtus ochrogaster).She left after feedingthe nestlings,which wcrc approximately10 daysold. At 10:02 a Red-headedWoodpecker (Melanerpes erythrocephalus) flew to the nestcavity and pccrcdinside. The male kcstrclthen stoopedon and pursuedthe woodpeckerwhich eludedit by flying low into the nearbywoodlot. On 9 May at 13:20 a Red-headedWoodpecker was sccn perched on the polejus• below the hole for 3 min. This twice chasedother Red-headedWoodpeckers when they landedon the pole, eachtime returningto the kcstrc]nest hole and peeringinside. It wasthen displacedby the femalekestrcl. On 15 May at 14:00 a pair of Red-headedWoodpeckers perched just beneaththe kcstrclhole. At 14:05 one of this pair chaseda CommonFlicker (Colaptesauratus) that passednearby. The Red-headedWoodpecker returned to the poleimmediately. This pair of woodpeckersremained on the pole for 6 min and periodicallypccrcd into the nest hole. At 14:11 thesewoodpeckers chased a conspecificpair from the area. The female kcstrclthen chasedboth woodpeckersfrom the area. During 9 h of observation,from 20 to 22 May, a woodpeckerpair wassccn at the kcstrclnest cavity continuously. During that time they chasedother Red-headedWood- peckers9 times,Common Flickers twice, and a Hairy (Picoides villosus) once. The female kcstrc]arrived twice with volesand displacedthe .On all oc- casionsthe woodpeckersreturned to the pole immediatelyafter the kcstrcldeparted. Between22 and 27 May the nesthole was observed for 18 h duringwhich the young kestrelsperiodically perched in the cavity opening,peering outside.The woodpeckers perchedjust below the hole during these periodsand moved up to the hole when the youngkcstrcls moved back down in the nestcavity. During this 5-dayperiod the Red- headedWoodpeckers chased conspecifics 20 times,Common Flickers 5 times,and Hairy Woodpeckersonce. They in turn wcrcdisplaced by the kcstrels15 times.One attackby the female kcstrc]was particularly aggressive; the struckthe woodpeckerhard enoughto dislodgeseveral contour feathers. On 27 May, 3 kcstrcls(2 male, 1 female)fledged from the nestcavity and later flew to a woodlot25 m distant.The next day they wcrc seen200 m awayin the powerlinc corridor.The Red-headedWoodpeckers wcrc observedentering the kcstrclnest cavity for the first time at 08:45 on 27 May, and subsequentlynested therein. Wc have found no previousrecords of kcstrclstolerating a nest competitor which wasactively defending the samenest site or of Red-headedWoodpeckers defending a nest polein useby kestrcls.--BRiA•TOLAND AND WILLIAM H. ELDER,School of Forestry, Fisheries andWildlife, University ofMissouri, Columbia, Missouri 54211. Received1 Aug. 1983;accepted 14 Feb. 1984.

Intraspecific Nest Parasitism in Willow Ptarmigan.--Intraspecific nest parasitism (femaleslaying eggs in nestsof conspecifics)is apparently rare amonggalliformes and has not been reported in ptarmigan.However, opportunitiesfor observingthis behaviorin thesespecies are restrictedbecause it isdifficult to distinguishbetween eggs from different individuals.In addition,ptarmigan nests are difficult to find during the laying period becauseof their sparsedistribution, the coveringof eggswith debris,and the secretive behaviorof hens.Here, I report observationsof intraspecificnest parasitism by Willow Ptarmigan(Lagopus lagopus) at La PerouseBay, on west coastHudson Bay, Manitoba, (58'24'N, 94'24'W). During the study,Willow Ptarmiganlaid 1 egg per day, occasionallyskipping a day