-, I i RAPTOR RESEARCH FOUNDATION RAPTOR RESEARCH REPORT NO. I T ! 1 ·- 1 FALCONIFORM REPRODUCTION; A REVIEW. PART 1. THE PRE-NESTLING PERIOD l by J Richard R. Olendorff Colorado State University l J J J ] Vermillion, South Dakota February 1971 I ,) J __j ~ I I " , __" J ~- i ' ' r.._, i I i r i i I i ' (i I ': ,_ _j ,/' This series, Raptor Research Reports, is issued by the Raptor I I Research Foundation, Inc., for recording materials such as literature ·, I L,._J reviews, bibliographies, translations, and reprints, to provide access to the often scattered primary sources. The series is inaugurated with (. the first part of a review . of serial literature on falconiform u reproduction. Editor of this report: Byron E. Harrell r' l i Price of Raptor Research Reports No. I -,· S2.00 for members of the Raptor Research Foundation r--. S2.50 for all others · · I' '' ''----- r-I' ,_j (~~ I \,_! : I I r ) J' I ( --. ', !, ,I l ,, I ·.. · I (~ ! I "-' P: (_ j 2 i l (__; I '~-' TABLE OF CONTENTS Page Introduction . 7 I. Anatomy and Morphology . .... 9 Bilateral Ovarian Development .................... 9 Gonadal development . 9 Species considerations ........................ II Sexual Dimorphism ............................. 12 2. Territory ............................. , . 14 General Considerations .......................... 14 Types of territory ............................ 14 r) Causes of variation ........................... 14 Stage of breeding cycle .................... .14 Individual idiosyncrasies ................... .15 Sex differences .......................... .15 Intra- and interspecific variation .............. I 5 Functions of territory ........................ 16 Sexual isolation ................. , ......... 16 Food supply ............................. 16 Ecological familiarity ..................... .16 Population dispersion ...................... 16 Design of a territory ........................... 16 Vegetationalfactors ....................... 17 Topography ............................. .17 Food supply ............................. 17 Territorial pressure . .17 Climate ................................ .18 Peregrine Falcon Territory ....................... 18 r; General description ..........................18 I ' Breeding density theories ...................... 18 \ I -~ Historical occupancy ......................... 19 Interspecific Relationships .......................20 r Provocation of attack .........................20 iI __ ''} . Mannerisms of the intruder ..................20 Size of the intruder ........................20 Stage of breeding cycle .....................20 Other interspecific considerations ............... 21 Relations with other raptors .................21 (A) Intrageneric relationships ............. 21 (B) Interspecific cooperation ..............21 (C) Interspecific nesting relationships ........22 Interspecific exclusion .................22 Relationships involving owls ............23 Relationships between eagles ............ 23 AI i ' ~ 3 (" I r --'"' I ~. ,1, __j - J CONTENTS-continued Page Close nesting ........................24 Maximum densities-interspecific ........25 'Maximum densities-intraspecific ........ 25 Semi-colonial nesting ..................26 Colonial n:esHng ......................26 Relations with n'<!ln~fakoniform- avian species· .... 26 (A} Close n~st\inl!: . ........ 2 !'i (B)· Various r.ap'tor, non-raptor,_ associations ...2-7 De§em:se- against\ n'On\.lmmart; non-avian- species- .. ·. 2S'· H!eds- (')'numalt\: inl(i!1Uilion ...· ... , ..... · .· ....· ...29' ~A) JDleil16&1!iiml ~ atltl;m!(............. · ...· .· .· ... .3'()) ~B)Valfiarlli~mlinl atlt'a~ .............. -.· .. ·.·.· .. -.3'01 I ~C) ~im1 t'GWardl ~ll&'OOII~ .· .· .· .·.· .. .3111 I .' 6D)ll141e~~il-all:ltla~ ................ ·.·.·.·.·.·.·.·.·.·.·.3'!1 'E)~ ' ! RJlllt!imt ,. ''-'~ .... ~lml ·· ....... •' ...... •' ....... · ....... · .· .· .·.·.· .-.3=1' I 3. Tllni: Jm1!.'GIIiimg C'l!<tli!:-G;ml!mtltlii!s- ,. ,. ,. ,...•.•. •' •' .......... · .·.·•· .·.·.. 3'2' ~t1li:l13111 C(\)JD!!jid\ntallli.ims; ....•.•.•...•.•.•.•...•.....•...•. ··•·•· •••·•· •• -.# T~ ...........................................................· ....... ·.·.·.·.-.3333 rn=.t~~~~- .. :::::::::::::::::::::::::::::::.:::::::::::::::::::::::~ B'Gl'<Didi91ll'IPJPllj' ............................... •' •. ,• •.•.•. •' •.•.•.•.•.• · •· •· .3-33 ~-:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::·:~ Mle~ ....... :· ................ ·: ·: ............................ ·.··················~ Bil~te!llitw l1li! nmmuru~ BUdS; ............................. · •.....•.• ·.3Sl A\1lsl!nuLt: lllil'J!oonw ~ ......................................... .3_:si (' Bmmuru~RS>attatUtu:~rtes;· ·······································.W (\ -4. Nastilll!! 3illl.ll.BSS> .. .. .. .. .. .. .. ... .. •. • . .• . .• . • . • . .• .. .. .• .. .• . .. .• . :/F Nasting 3Uuaassi.-<lientlltlllttils> ... .. .. .. .. .. .. .. .. .. .. .. .. .. .......... ~ 1Datl1iitmntt!lllfim1tlm;A\fThol:titli!I%stln!llSU~ ............... ~ I : I ; !igg;!lw!; ......................................... ·.······················ ·.·.~ \ _,'i \\IW!ttiB!T ........................... '• ...... '• .........• '• .•.•... , '• '• .... ~ Alaniiianm ............................................................. ~ r ~ ................................... ·.·························-~ ( : ID:Battllaff)!OllnlJ! ......................................................... 4UJ ( .,t' <rannil±sllmn ................. :... ...................................... 4UJ (@.l!Haalbss ......................................................... 4W (ffil~ ....................................................... 441 C(()lHhlhrum...................................................... 'HI IDsMS~re . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. •. .. .. .. .. .. .. .. ...... 44 1 r ffiue.ntallfli:.o!OJS> ......................................................... 4-!2 !Thserritmt .............................................................. 4-!2 i ! ' -'J lhferrilit~y .......................................................... -H2 fuu rossHhlimtm!!t'\'eesi:inggS'illltcesss. .. .. .. .. .. .. .. .. .. .. .. .-H.1 ,::.:, \ .: c.J I - (~ ' 5 CONTENTS-continued Page Laying second clutches ....................... .43 Acquisition of a new mate .................... .45 Raising of young by a single parent ............. .47 5. Preincubation Behavior . 48 Introduction ................................. .48 Pairing ................................•..... .49 General information ......................... .49 Polygamy ..................................51 \_,I European Sparrow-hawk ....................51 Marsh Hawk and Marsh Harrier ...............51 ,. Montagu's Harrier .........................5 I I ' Peregrine Falcon ..........................52 i European Hobby ..........................52 Common Kestrel ..........................52 'I '. Additional Comments ......................52 ' ' Mutual Roosting .............................53 l.~· Cooperative Hunting .........................53 Courtship Flights ............................54 Red-tailed Hawk ..........................54 Red-shouldered Hawk ......................54 Eagles ..................................54 Marsh Hawk ............................ .55 (I Peregrine Falcon ..........................56 l ! ,j American Kestrels .........................56 Familiarities .............................. ,. .. 57 Courtship Feeding ...........................57 Copulation .................................59 General considerations .....................59 Pre-copulation behavior .....................60 Post-copulation behavior ....................60 The copulatory act ........................61 Red-tailed Hawk ........................61 (' Gray Hawk ............................61 Marsh Harrier ..................... ·...... 61 "I / Peregrine Falcon ........................61 Merlin ................................62 American Kestrel ....................... 62 \ __ j Nest-Scraping ............................ , .... 63 6. Nests and Nesting . 65 Site Choice ...................................65 Site-selection tours ...........................65 Roles of the sexes ............................65 The Peregrine Falcon .........................66 ! \ _,J I' '' . ..J 6 CONTENTS-continued Page (' ~-- .. I Multiple Nesting ..................•.......•... o67 ' . Roles of the Sexes in Nest Building o••.••••••••• oo o.68 ., r Nest Building .... ·..... 0 ••••••••••••••••••••••••69 j i Green Material ....... 0 ••••••••••••• o •••••••••..70 Occurrence of the phenomenon .................70 Functions ............... ·. ~ .................72 Nest Sanitation ................................73 Nest Parasites .......... o ••••••••••••••••••••••74 Flies ......................................74 Ticks .....................................76 r' 7. Eggs and Egg-laying . 78 i I Eggs-Physical Characteristics ......... o •••••••••••78 Determinant or Indeterminant? .... 0 ••• o••• 0 •••••• 079 Timing of Egg-laying ............ o••• o o oo •• o • o o o 079 I I Sequence of Laying 0 .•••••.••••• , ••• o o • o• 0 ••••••• 80 Clutch Size ........ o••• 0• o•••• o•• o •• o••••• 0• 0 080 Variation . o ••••••.•• 0•••• o•••••••• o• 0 ••••••81 (' Species considerations 0•••••••••••••• 0• o 0 •••••82 8. Incubation ........ o ••• 0•••.••• o••••••.•••••• o • • • 84 / ,' Temperature Regulation and Egg Weight Loss ....... 0 o84 Incubation temperature . o 0 ••••••••••••••••••••84 ,.·-~ ' Egg weight loss ....... o • 0••••••••