Antler casting in relation to parturition in semi-domesticated female reindeer

Rangi e , 33, (1) 2013 32 (1), 2012 This jou nal is published unde he e ms o he C ea i e Commons A ibu ion 3.0 Unpo ed License Edi o in Chie : Bi gi a Åhman, Technical Edi o E a Wiklund and G aphic Design: Be il La sson, www. angi e .no Rangi e , 33, (1), 2013: 17-24 17 B ie Communica ion An le cas ing in ela ion o pa u i ion in semi-domes ica ed emale eindee Eigil Reime s1, Mau i Nieminen2 & Di ess Tsegaye1,3 1Depa men o Biosciences, Pos box 1066, Uni e si y o Oslo, 0316 Oslo, No way (Co esponding au ho : eigil. eime [email protected]). 2Finnish Game and Fishe ies Resea ch Ins i u e, Toi oniemen ie 246, 99910 Kaamanen, Finland. 3Depa men o Ecology and Na u al Resou ce Managemen , Pos box 5003, No wegian Uni e si y o Li e Sciences, 1432 Ås, No way. Abs ac : We in es iga ed he iming o he igh and le an le cas ing in semi-domes ica ed eindee (Rangi e a andus a andus L.) in ela ion o pa u i ion using 139 an le ed adul indi idually ma ked emales in 2008-09 be ween May 5 and June 2; a pe iod when all cal es we e bo n and all emales cas hei an le s. We analysed ime o cas ing o igh and le an le in ela ion o p egnancy, emale age and body weigh , weigh and sex o he cal , and bi h da e. Se en o he emales we e non-p egnan (ba en) and cas hei an le s du ing he second week o May and a he same ime as some o he emales ha ga e bi h ini ia ed an le cas ing. Pos pa um e en ion o an le s a ied om 0 o 15 days. We ound no di e ence be ween le and igh an le cas ing schedule and wi hin wo days apa , 91% o he emales had cas bo h an le s. The maximum numbe o an le cas ings pe day occu ed on he se en h day a e pa u i ion. O he 132 emales ha ga e bi h, 7 emales (5.3%) cas bo h an le s 5 – 23 days be o e cal ing, h ee emales cas igh an le 6 – 10 days be o e and he le an le 2 – 5 days a e cal ing and one emale ha bo e only a le an le cas ed a day be o e cal ing. An le cas ing among lac a ing emales was ela ed only o emale age, indica ing ha olde emales cas an le s ea lie han younge emales (i.e. 3 days ea lie han he pooled mean o 7.6 days). Apa om cal ing da e being wo days la e among he 7 emales ha al e na ed hei cas ing schedule, emale body weigh s, cal sex and cal bi h weigh among hem did no di e be ween he wo yea s. We conclude ha i is a small bu consis en an le cas ing o e lap be ween ba en and p egnan /lac a ing emales, indica ing ha he con ol mechanism o cas ing o an le s is no “ ool p oo ” and ha an le s a us p io o pa u i ion does no accu a ely p edic p egnancy s a us in his domes ic eindee g oup. Key wo ds: an le cas ing; pa u i ion; p egnan emales; ba en emales; semi-domes ica ed eindee ; Rangi e . a an- dus. In oduc ion In mos dee species (Ce idae), g ow h o an - le s is a male seconda y sexual cha ac e is ic. The single excep ion is eindee and ca ibou (Rangi e a andus) in which bo h sexes p oduce an le s and he e o e p o ide a pa icula ly in- e es ing case when s udying dominance ela- ionships. Howe e , ela i e an le size se es as a seconda y sexual cha ac e is ic in his spe- cies because emale an le s a e ela i ely smalle han hose o males. The annual ene ge ic and nu i ional oll o Rangi e , 33, (1) 2013 This jou nal is published unde he e ms o he C ea i e Commons A ibu ion 3.0 Unpo ed License Edi o in Chie : Bi gi a Åhman, Technical Edi o E a Wiklund and G aphic Design: Be il La sson, www. angi e .no 32 (1), 2012 an le enewal (Goss, 1983) sugges s ha se- lec ion would ha e supp essed his ai i i we e no ad an ageous o he indi iduals. The an le s o emale eindee ha e p obably been bo h e ol ed and e ained because o hei g e- ga ious beha io and he s ess ul condi ions in win e compa ed o o he ce ids (Henshaw, 1968; Espma k, 1971; Robe s, 1996; Geis , 1999). Ca ying hei an le s all win e seems o gi e emales a clea ad an age in compe i- ion o ood in ha c i ical season (Ba e e & Vandal, 1986). Dominance ela ionships in e- male g oups o semi-domes ica ed eindee e- la e o age, an le size and body size (Kumpula e al., 1990). In a ollow up s udy Kumpula e al. (1992) ound he dominance ela ion- ships in emale eindee g oups changed a e an le emo al and sugges ed ha in a-he d compe i ion in win e may ha e a o ed an le de elopmen in emale eindee . La e , Hol- and e al. (2004) in es iga ed he in luence o body mass, an le size and age on social ank and concluded ha bo h body mass and age a e good p edic o s o social ank in emale ein- dee , whe eas an le size in compa ison plays a less impo an ole in he ds wi h a “no mal” emale age s uc u e. This sugges ed ha emale an le s may ha e e ol ed in in e -sexual a he han in a-sexual compe i ion. Howe e , phe- no ypes wi hou an le s occu egula ly in all popula ions, al hough hei equency a ies g ea ly (Reime s, 1993; Schae e & Mahoney, 2001) hus indica ing a less clea cu ela ion- ship be ween an le s and dominance. The phenology o an le cas ing in emale eindee and ca ibou is no simple and seems o be ela ed o pa u i ion (Espma k, 1971). The iming o he igh and le an le cas ing and he o e all s ong ela ionship o an le cas ing o pa u i ion indica ing an endoc ine con ol, possibly s e oid le els as eco ded among ein- dee cal es (Blake e al., 1998). Non-p egnan emales usually cas an le s a ew weeks be o e he cal ing season, whe eas p egnan emales cas a ew days a e gi ing bi h (Len , 1965; Espma k, 1971; Be ge ud, 1976). As mos adul males a e absen om he cal ing g oups a his ime (Thomson, 1977) his in a-sex di - e ence in an le cas ing is in iguing. This s udy is a ollow up o Espma k (1971) o u he in es iga e emale eindee an le cas ing schedule in ela ion o pa u i ion as p e ious indings a e ei he con lic ing o in- conclusi e. Me hods In conjunc ion wi h a popula ion gene ic s udy in an expe imen al eindee he d in Kaamanen in no he n Finland (69o10´N) du ing he cal - ing seasons in 2008 and 2009, a o al o 139 an le ed adul indi idually ma ked emales, o which 7 we e non p egnan (ba en), we e obse ed be ween May 5 and June 2. Du ing his pe iod all cal es we e bo n and all emales cas hei an le s. The age o he emales was be ween 2 and 14 yea s. Du ing he win e mon hs eindee we e in supplemen a y eeding (silage and concen a es, Po onhe kku, Raisio) bo h yea s in he o es a ea. The emale age and body weigh , bi h da e, weigh and sex o he cal , an le s a us and ime o cas ing o igh and le an le we e eco ded. P io o model es ing we an - es s o esol e he ques ion o possible di e ences in an le cas ing schedule be ween le and igh an le . We ound no di - e ence and decided o un linea mixed-e ec s models (LMM) o an le cas ing a e bi h (le and igh combined) i ed wi h indi idual and yea as andom e ec s o con ol o epea ed measu es. An le cas ing may a y wi h emale age a pa u i ion, weigh be o e cal ing, and o sp ing sex and weigh . To con ol o hese a ia ions we i ed hese as ixed-e ec ac o s in he models. We also p oduced he p obabili y plo s o cal ing da es and an le cas ing schedule (cas - ing s. no cas ing) in ela ion o da es (i.e. as p edic o a iable) om May 1 o June 2 using 18 Rangi e , 33, (1) 2013 32 (1), 2012 This jou nal is published unde he e ms o he C ea i e Commons A ibu ion 3.0 Unpo ed License Edi o in Chie : Bi gi a Åhman, Technical Edi o E a Wiklund and G aphic Design: Be il La sson, www. angi e .no 19 logis ic eg ession. All analyses we e done in R e sion 2.15.1 (R De elopmen Co e Team, 2012). Resul s Among he 139 an le ed emales, wo o which we e an le less on one side and se en o he wo-an le ed we e ba en and cas hei an le s du ing he second week o May (Fig 1.). O he 132 emales ha ga e bi h, 7 emales (5.3%) cas bo h an le s 5 – 23 days be o e cal ing, h ee emales cas igh an le 6 – 10 days be o e and he le an le 2 – 5 days a e cal ing and one emale bo e only a le an le ha we e cas one day be o e cal ing (Fig. 1). We ound no signi ican di e ence be ween le and igh an le cas ing schedule ( = 0.28, P = 0.78) among emales ha ga e bi h. Six y pe cen o he emales ha ga e bi h and ha ca ied wo an le s cas bo h an le s on he same day, 21% one day apa , 10% wo days apa and he emaining 8% be ween h ee and 11 days apa (Fig. 2). An le cas ing among lac a ing emales was ela ed only o emale age, indica ing ha olde emales cas an le s ea lie han younge emales (i.e. 3 days ea lie han he pooled mean o 7.6 days; = -2.84, P = 0.01). O he possible in lu- en ial ac o s like emale body weigh in Ap il, cal body weigh o sex did no in luence an le cas ing and we e emo ed om he inal model (P > 0.05). Logis ic eg ession plo s (Fig 3A, B) Fig. 1. An le cas ing schedule among adul 2+ yea old domes ic eindee emales in Kaamanen, Finland in 2008 and 2009.  8 13 17 21 25 29 Days a e 1 May F equency o le an le cas ing 0 5 10 20 Lac a ing emales Ba en emales 8 13 17 21 25 30 Days a e 1 May F equency o igh an le cas ing 0 5 10 20 Lac a ing emales Ba en emales -23 -5 1 4 7 10 15 Days a e cal ing F equency o le an le cas ing 0 5 10 20 A e bi h Be o e bi h -23 -7 1 4 7 10 15 Days a e cal ing F equency o igh an le cas ing 0 5 10 20 A e bi h Be o e bi h Rangi e , 33, (1) 2013 This jou nal is published unde he e ms o he C ea i e Commons A ibu ion 3.0 Unpo ed License Edi o in Chie : Bi gi a Åhman, Technical Edi o E a Wiklund and G aphic Design: Be il La sson, www. angi e .no 32 (1), 2012 20 depic s ha bo h cal ing day and an le cas - ing schedule show simila end wi h inc easing days om May 1 o June 2. Howe e , an le cas ing schedule eached maximum h eshold ew days ea lie han he a e age cal ing da e indica ing ha some o he emale eindee cas hei an le be o e cal ing. Cal ing occu ed ea lie in 2009 han in 2008 (Fig. 2); median da e 13 h o May s. 16 h o May. Median cal ing da e in a pooled sample om bo h yea s was 14 h o May. Fe- males ha ga e bi h in 2008 cas hei le and igh an le 7 days pos pa um s. 5 days pos - pa um in 2009. Among he 139 an le ed emales, 54 indi- idual emales we e sampled in 2008 and again in 2009 and made possible an e alua ion o indi idual an le cas ing schedule in wo con- secu i e yea s. All o hem ga e bi h bu an le cas ing schedule was di e en . Only one emale cas bo h an le s be o e cal ing (13 days) in 2008 while he emaining 53 cas hei an le s a e cal ing. In 2009 he one emale ha cas 13 days be o e cal ing cas an le s wo days a e cal ing bu 6 emales ha cas an le s a e cal ing in 2008 cas hei an le s be o e cal ing. Discussion The e was an o e lap in an le cas ing be ween he an le ed ba en and p egnan emales and some p egnan emales also cas hei an le s be o e gi ing bi h. In a s udy o indi idually ma ked emales, Espma k (1971) eco ded he exac cas ing schedule o 45 an le ed p egnan emales and ound ha cas ing ook place 1-11 days and a mean a 5-6 days pos pa u i ion. Fig. 2. Numbe o days di e ence be ween an le cas ing o igh s. le an le and cal ing da es in May among adul 2+ yea old domes ic eindee emales in Kaamanen, Finland in 2008 and 2009. Fig. 3. P obabili y o cal ing days and an le cas ing schedule among adul 2+ yea old domes ic eindee e- males in ela ion o days om May 1 o June 2 i ed wi h logis ic eg ession. Rangi e , 33, (1) 2013 32 (1), 2012 This jou nal is published unde he e ms o he C ea i e Commons A ibu ion 3.0 Unpo ed License Edi o in Chie : Bi gi a Åhman, Technical Edi o E a Wiklund and G aphic Design: Be il La sson, www. angi e .no 21 While none o he p egnan emales in he Espma k (1971) s udy cas an le s be o e cal - ing, one ou o 54 in 2008 and 6 ou o 54 in 2009 in ou s udy cas hei an le s be o e cal ing. The eco ded o e lap in an le cas ing pa e n suppo ea lie indings bo h among eindee (Sokolo , 1959; Wika, 1980; Lead- e -Williams, 1988) and ca ibou (Len , 1965; Kelsall, 1968; Skoog, 1968; Be ge ud, 1976; Thing e al., 1986). Such de ia ions in da es o an le cas ing may be mo e common han p e iously acknowledged. In a la ge he d o ca ibou s udied du ing he 1986 cal ing sea- son in Quebec-Lab ado , Canada, Gagnum & Ba e e (1992) ound ha , con a y o expec- a ions, a high p opo ion o emales (13.5%) cas hei an le s ≥ 2 weeks be o e gi ing bi h. An le cas ing schedule among lac a ing e- males was ela ed o emale age indica ing ha olde emales cas an le s ea lie (3 days) han he pooled mean o 7.6 days. Mu ie (1935) and Ban ield (1954) epo co esponding endency while Espma k (1971) ound no signi ican di - e ence. The majo i y o lac a ing emale cas an le s pos pa um on day 7 in ou s udy and 1 day ea lie in Espma k (1971). Inspec ing ba en g ound ca ibou in No hwes Alaska, Len (1965) epo ed ha none among 1600 emales e ained an le s o mo e han a week pos pa um. We ound ha 91% o he emales had cas bo h an le s wi hin wo days apa , and his schedule co esponds o Espma k (1971) who epo ha usually bo h an le s we e cas on he same day. Appa en ly, he o e lap o an le cas - ing schedule among lac a ing and ba en ein- dee emales in sp ing indica es ha he con ol mechanism o cas ing o an le s is no “ ool p oo ” and ha some en i onmen al ac o s may in e ac . Ou knowledge o he unde ly- ing de elopmen and endoc ine mechanisms in eindee is limi ed. Annual endoc ine p o iles in adul s (Bubenik e al., 1997; Bo isenko , 2001) and s udies on he e ec s o gonadec- omy in bo h adul s (Lincoln & Tyle , 1994) and cal es (Lincoln & Tyle , 1999) collec i ely indica e ha s e oid ho mones, es os e one in males and es adiol in emales, a e impo an egula o s o he eindee an le cycle (Blake e al., 1998). The abili y o es os e one and es a- diol o p e en he old an le s om being cas , o inhibi new ones om egene a ing, and o cause he el e o cas p ema u ely om g owing an le s may be aken o indica e a gen- e al endency o ei he sex ho mone o b ing abou o o p ese e he ma u e condi ion o an le s (Goss, 1968) suppo ing a hypo hesis pu o wa d by Wislocki e al. (1947). Es a- diol s imula es he g ow h and mine aliza ion o he an le bone and he cleaning o he el- e (Lincoln & Tyle , 1999). Whe he es adiol also supp esses he cas ing o he ha d an le s as sugges ed by Lincoln & Tyle (1999) is un- ce ain as Shipka e al. (2007) epo es adiol a baseline concen a ions un il app oxima ely 24 week o ges a ion and ising coinciden ly as p oges e on declined jus be o e pa u i ion. Al hough unce ain y as o he de ailed con ol mechanism he s e oids appa en ly ac o syn- ch onize he an le cycle o he seasonal ep o- duc i e cycle wi h he ha d an le s unc ioning as weapons and social signal bo h in in a-sex- ual and in e -sexual compe i ion in win e and in sp ing (Lincoln & Tyle , 1994). The endoc ine con ol ensu es ha he ha d an le s a e e ained h oughou he au umn and win e when he emales a e no mally p egnan and when compe i ion o e ood and ood c a- e s in he snow is mos in ense. Cas ing an le s on he cal ing g ound also p o ides emales wi h a supply o mine als a a ime o likely mine al de iciency a e pa u i ion and a long win e o eeding on mine al-poo lichens, and g ea mine al need a he beginning o lac a ion (Wika, 1982; Ba e e, 1985) and du ing an le g ow h (Baksi & Newb ey, 1989). We conclude ha i is a small bu consis en an le cas ing o e lap be ween ba en and p eg- Rangi e , 33, (1) 2013 This jou nal is published unde he e ms o he C ea i e Commons A ibu ion 3.0 Unpo ed License Edi o in Chie : Bi gi a Åhman, Technical Edi o E a Wiklund and G aphic Design: Be il La sson, www. angi e .no 32 (1), 2012 22 nan /lac a ing emales in his domes ic eindee g oup and ha an le cas ing wi hin same e- male g oup may a y be ween yea s. Al hough we ha e no indi idual con ol o an le cas ing schedule in wild eindee emales, an le size da a om ou wild eindee a eas in sou he n No way o e he pas 22 yea s indica e ha ba en emales cas hei an le s be o e he cal - ing season (based on he size o hei new an - le s and no cal a oo ) (Reime s, 2006) and E. Reime s (unpublished da a). One subs an ially impo an ques ion e- mains: despi e he sys emic endoc ine con ol o he an le cycle, wha local ac o s may in- e ac wi h an le cas ing pa e n in ba en and p egnan /lac a ing emale Rangi e ? Explana- o y candida es include eco ypes (e.g. semi- domes ic o wild Rangi e ), nu i ion, and a ailabili y o mine als. Indi idually eco ded an le cas ing is all wi h semi-domes ic ein- dee on supplemen a y eeding in win e (ou s udy) and in enced in a eas which may impac na u al beha io , physiology and an le cas ing schedule du ing he cal ing season. P esence o absence o male eindee in he enclosu es may also be an in e ac ing ac o . Aknowledgemen s We hank he Finnish Reindee He de ´s As- socia ion and hei c ew a Kaamanen Expe i- men al S a ion, and Heikki Tö mänen and Jukka Sii a i in Finnish Game and Fishe ies Resea ch Ins i u e, Reindee Resea ch S a ion o help wi h da a. Re e ences Baksi, S. N. & Newb ey, J. W. 1989. Bone me abolism du ing an le g ow h in emale ca ibou. — Calci Tissue In 45: 314-317. Ban ield, A. W. F. 1954. P elimina y in es iga- ion o he ba en g ound ca ibou. Pa II. Li e his o y, ecology, and u iliza ion. 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Mausc ip ecei ed 23 June, 2013 e ision accep ed 18 Oc obe , 2013 23 Rangi e , 33, (1) 2013 This jou nal is published unde he e ms o he C ea i e Commons A ibu ion 3.0 Unpo ed License Edi o in Chie : Bi gi a Åhman, Technical Edi o E a Wiklund and G aphic Design: Be il La sson, www. angi e .no 32 (1), 2012 Ge i elling hos einsimle i elasjon il kal ing Abs ac in No wegian/Sammend ag:Vi unde søk e idspunk e o elling a ge i ene hos 139 indi- iduel me kede am ein (Rangi e a andus a andus L.) i o hold il kal ings idspunk e i 2008- 09 mellom 5. mai og 2. juni, en pe iode da alle kal ene ble ød og alle simle kas e sine ge i . Vi egis e e idspunk e o elling a høy e og ens e ge i i o hold il d ek ighe , simlas alde og k opps ek , kal ens ødsels ek og kjønn og ødselsda o. Sy a simlene a gjeldsimle (ikke d ek ige) og kas e sine ge i i løpe a and e uken i mai og på samme id som seks a simlene som ød e kal kas e ens e ge i og ni a dem kas e høy e ge i . Felling a ge i ene e e ødsel a i- e e a 0 il 15 dage . Vi an ingen o skjell i ellings idspunk a ens e og høy e ge i og innen o dage hadde 91% a simlene kas e begge ge i . Maksimal an all ge i ellinge skjedde sy ende dag e e ødsel. A de 132 simlene som ød e kal , kas e 7 (5,3%) begge ge i 5-23 dage ø kal ing, e simle el e høy e ge i 6-10 dage ø og ens e ge i 2-5 dage e e ødsel. En simle hadde ba e ens e ge i som ble el en dag ø kal ing. Ge i elling blan simle med kal a kun kny e il simlenes alde . Eld e simle el e ge i e 3 dage idlige e enn samle gjennomsni på 7.6 dage . Vi egis e e ge i ellingsmøns e e hos 54 simle i 2008 og igjen i 2009. Alle ød e kal de espek i e å ene, men ellingsmøns e e a o skjellig. I 2008 kas e ba e én simle begge ge i ø kal ing (13 dage ), mens de es e ende 53 kas e sine ge i e e kal ing. I 2009 kas e den sim- la som kas e 13 dage ø kal ing si ge i o dage e e kal ing, men nå kas e seks simle som kas e ge i e e kal ing i 2008 sine ge i ø kal ing. Bo se a a kal ingsda oen a o dage sene e blan de sy simle som end e ellingsskjema i o hold il kal ings idspunk , a de ingen sammenheng il simlenes alde elle k opps ek elle il kal ens kjønn og ødsels ek . Vi konklud- e e med a de e en li en, men gjennomgående o e lappende ge i elling mellom gjeldsimle og d ek ige/ammende simle , noe som ise a kon ollmekanismen o ge i elling ikke e “ eil i”, og a ge i s a us ø ødsel ikke nøyak ig o u sie d ek ighe ss a us i denne am ein lokken. 24