Population Ecology of the Ural in : some results from a 48-year study

This is a reduced version of an oral presentation given by Pertti Saurola in Elabuga, Tatarstan 23.9.2013

Photo Olli Saksela Why? Conservation: the traditional nest sites were ”cleaned” from Nestbox program 1965– How the Ural Owl has adapted to cyclic environment? cycle: • low • increase • peak • (decrease) Effects on : • number of breeding pairs • laying date • clutch size • fledglings per breeding pair • survival • dispersal • recruitment Ural Owl is a generalist feeder and for that reason a resident species Ringing, recaptures and recoveries

The data of my study consists of nestlings and breeding adults ringed and later recaptured alive by me or other ringers, or found dead and reported to the Ringing Centre by the general public It is easy to catch the females! But how to catch for ringing and recaptures the adult males? Catching Ural Owl and males

• Stuffed Ural Owl (or Tawny Owl) sitting on a loudspeaker and surrounded by mistnets • Trap in front of the nestbox – In the evening, close the female and at least 7–10 days old young in the nestbox and give some extra food (mice) to them – Set a funnel trap (see picture) in front of the nestbox – Early in the morning, remove the trap and release the

Finland, the country of owl ringers! Number of owls ringed in Finland in 1913–2012

Species Ringed Encountered

Eagle Owl 15 802 3 477 74 8 Hawk Owl 3 588 56 Pygmy Owl 48 012 3 505 Tawny Owl 50 029 13 405 Ural Owl 58 430 15 782 3 109 178 Long-eared Owl 14 876 604 Short-eared Owl 7 558 300 Tengmalm’s Owl 125 883 6 416 Life of the Ural Owl in cyclic environment.

Data from my study area Colours of the vole cycle: • low • increase • peak

Survival Survival of Ural Owls 1968–2005 based on all data from Finland Survival of Ural Owls - Model VW 1.0

0.9 0.8 0.8

0.7

0.6

0.5 Survival 0.4 0.3 0.3

0.2

0.1

0.0 19681968 1972 1976 1980 1980 1984 1988 1992 19961992 2000 2004 2000 2008 2005 Year Recruitment of young hatched in increase or peak years

Conclusion: Most of the huge production during the peak years is ”wasted” because of the low survival after the crash of the vole populations!

Conclusion: Recruitment of young hatched in low vole years may be very high in relation to the small total number of young produced in those years.

Lifetime reproduction Conclusion • Very few individuals transfer their genes to the next generation Dispersal • Natal dispersal = ”movement between the natal area and the area where breeding first takes place” (Clobert et al. 2001) • Breeding dispersal = ”movement between two successive breeding areas” Ural Owl: Natal Dispersal Females Males • Males • Median = 16 km • Females • Median = 25 km

• Found dead • Median = 30 km Pair bond Male Female Is the following general statement in handbooks true? ”Pair-bond is life-long, and maintained all year” (BWP). • N= number of pairs of a female and male which have bred together (at least once) and which have been verified alive in a later breeding season • Divorces = number of pairs which separated Two possibilities to calculate ”divorce” rate:

• N1 = Number of pairs

• N2 = Number of ”pair-years” ”Divorces” in Ural Owl

Area N1 Divorces Div. Rate Hauho 128 12 9.4%

Area N2 Divorces Div. Rate Hauho 263 12 4.6% Supermale Ural Owl D-113116 of HYYPIÖ! Joenkylä

Hyypiöö Pyhäniemi Joenkylä Hyypiö Pyhäniemi Male Female Male Female Male Female 1991 JOUKO Mamma –––––– –––––– Pekka Petra 1992 JOUKO Jonna PAPPA Mamma Pekka Petra 1993 JOUKO –––––– PAPPA Mamma –––––– –––––– 1994 JOUKO Mamma –––––– –––––– Pekka Petra 1995 –––––– –––––– –––––– –––––– –––––– –––––– 1996 PAPPA Mamma PAPPA HEILA –––––– –––––– 1997 PAPPA Mamma –––––– –––––– PAPPA HEILA 1998 –––––– –––––– PAPPA HEILA –––––– –––––– 1999K PAPPA HEILA PAAVO PAULA 1999S JASKA JAANA PAPPA HETA PAAVO PAULA PASI 2000 JASKA JAANA PAPPA HETA (Paavo) PAULA 2001 JASKA JAANA PAPPA HETA PAAVO PAULA Joenkylä Hyypiö Pyhäniemi Male Female Male Female Male Female 2002 JASKA JAANA HEIKKI ------PAAVO PAULA 2003 JASKA JAANA ------PAAVO PAULA 2004 (Jaska) JAANA ------–––––– –––––– 2005 JASKA JAANA HANNU HETA PAAVO PAULA 2006 JASKA JAANA HANNU HETA PAAVO PAULA 2007 ------–––––– –––––– 2008 (Jaska) (Jaana) HANNU HENNA PAAVO PAULA 2009 JASKA JAANA HANNU HENNA PAAVO PAULA 2010 JASKA HENNA ------2011 JASKA

Supermale PAPPA, comments 1: • When PAPPA started his breeding career at the age of 4 years in 1992 with MAMMA, he caused a divorce • After the breeding season of 1993 MAMMA joined again with Jouko and bred with him in 1994. • PAPPA was away during 1994–1995 • In 1996 and 1997 PAPPA had two females • In 1996, MAMMA laid 3 eggs and 3 nestlings hatched. Because PAPPA took care only of the nestlings of HEILA, only one of MAMMA’s nestlings fledged after very slow development Supermale PAPPA, comments 2. • After 1997 MAMMA moved away and continued to breed 10 km away from PAPPA’s • In spring 1999, PAAVO, one of PAPPA’s sons in 1997, started to breed in his NATAL nestbox in Pyhäniemi !!! • In autumn 1999, JASKA, one of PAPPA’s sons in 1997, was captured in his NATAL nestbox in Joenkylä, where he also started to breed 2000–!!! • JAANA and PAULA, the females of JASKA and PAAVO were SISTERS from a nestbox 13 and 16 km away from Joenkylä and Pyhäniemi !!! What do you see in the next slide? ??? The Answer: • The oldest nestling is a Tawny Owl ( aluco) • The three others are Ural Owls (Strix uralensis) • When I visited the nestbox for the first time, there were no adults and no eggs, but a big bowl made surely by the Ural Owl in nesting material • During the second visit, the Ural Owl female flew out and there was one small egg • Later there were three normal Ural Owl eggs and one small egg; and finally four young Kiitos!