Fear of the dark? A mesopredator mitigates large carnivore risk through nocturnality, but humans moderate the interaction.

While constrained by endogenous rhythms, morphology and ecology, animals may still exhibit flexible activity patterns in response to risk. Temporal avoidance of interspecific aggression can enable access to resources without spatial exclusion. Apex predators, including humans, can affect mesopredator activity patterns. Human context might also modify temporal interactions between predators. We explored activity patterns, nocturnality and the effects of human activity upon a guild of carnivores (grey wolf, Canis lupus; Eurasian lynx, Lynx lynx; red fox, Vulpes vulpes) using travel routes in Plitvice Lakes National Park, Croatia. Humans were diurnal, foxes nocturnal and large carnivores active during the night, immediately after sunrise and before sunset. Carnivore activity patterns overlapped greatly and to a similar extent for all pairings. Activity curves followed expectations based on interspecific killing, with activity peaks coinciding where body size differences were small (wolf and lynx) but not when they were intermediate (foxes to large carnivores). Carnivore activity, particularly fox, overlapped much less with that of diurnal humans. Foxes responded to higher large carnivore activity by being more nocturnal. Low light levels likely provide safer conditions by reducing the visual detectability of mesopredators. The nocturnal effect of large carnivores was however moderated and reduced by human activity. This could perhaps be due to temporal shielding or interference with risk cues. Subtle temporal avoidance and nocturnality may enable mesopredators to cope with interspecific aggression at shared spatial resources. Higher human activity moderated the effects of top-down temporal suppression which could consequently affect the trophic interactions of mesopredators.Nacionalni Park Plitvička Jezera (Plitvice Lakes National Park), The Bernd Thies Foundation, EuroNatur, Bangor University, The UK Wolf Conservation Trust, The Coalbourn Charitable Trust, Ann Vernon Memorial Travel Fund and Sir Ian McKellen.http://link.springer.com/journal/265pm2020Centre for Wildlife Managemen

Fear, foraging and olfaction: how mesopredators avoid costly interactions with apex predators

Where direct killing is rare and niche overlap low, sympatric carnivores may appear to coexist without conflict. Interference interactions, harassment and injury from larger carnivores may still pose a risk to smaller mesopredators. Foraging theory suggests that animals should adjust their behaviour accordingly to optimise foraging efficiency and overall fitness, trading off harvest rate with costs to fitness. The foraging behaviour of red foxes, Vulpes vulpes, was studied with automated cameras and a repeated measures giving-up density (GUD) experiment where olfactory risk cues were manipulated. In Plitvice Lakes National Park, Croatia, red foxes increased GUDs by 34% and quitting harvest rates by 29% in response to wolf urine. In addition to leaving more food behind, foxes also responded to wolf urine by spending less time visiting food patches each day and altering their behaviour in order to compensate for the increased risk when foraging from patches. Thus, red foxes utilised olfaction to assess risk and experienced foraging costs due to the presence of a cue from gray wolves, Canis lupus. This study identifies behavioural mechanisms which may enable competing predators to coexist, and highlights the potential for additional ecosystem service pathways arising from the behaviour of large carnivores. Given the vulnerability of large carnivores to anthropogenic disturbance, a growing human population and intensifying resource consumption, it becomes increasingly important to understand ecological processes so that land can be managed appropriately.Table S1: Considerations proposed for the application of the giving-up density framework in field research and how the methodologies created in this paper accounted for these considerations.Table S2: Ethogram describing behaviours recorded (Bold font). Other behaviours that might accompany or be performed alongside those recorded are described in plain text.Bangor University, The UK Wolf Conservation Trust, The Coalbourn Charitable Trust, Ann Vernon Memorial Travel Fund and Sir Ian McKellen.http://link.springer.com/journal/442am2018Centre for Wildlife Managemen

Uzroci smrtnosti vukova u Hrvatskoj u razdoblju od 1986. do 2001.

We recorded a total of 92 dead grey wolves (Canis lupus) in Croatia during the period1986-2001: 60 (65.2%) were shot, 18 (19.6%) died as a result of traffic accidents, while the cause of death of 6 (6.5%) wolves remained unknown, 5 (5.4%) suffered from rabies, and one each was killed by axe, by hay-fork, and by other wolves. Among dead wolves the share of females was 56%, mean age was 1.9 years, and the mean mass of adult wolves was 31.4 kg. We analyzed separately the 10 years (1986-1995) preceding, and the first 6 years (1996-2001) after the legal protection of the species (15 May 1995), when 30 and 62 wolves died, respectively. Annual mortality rose from 3.0 prior to protection to 10.3 after protection (3.4 times). This increase in mortality indicates no enforcement of the legal protection, as well as an increase in animosity by local people; it was also partly influenced by wolf population growth and it would appear that the recorded mortality is sustainable. We propose to adapt the legislation to permit the controlled hunting of wolves. This would in all likelihood lead to decreased animosity and would keep the wolf population safe from uncontrolled hunting.Od 1986. do 2001. zabilježena je smrt ukupno 92 siva vuka (Canis lupus) u Hrvatskoj: 60 (65.2%) su ustrijeljena, 18 (19.6%) je poginulo u prometnim nezgodama, za 6 (6.5%) vukova je uzrok smrti ostao nepoznat, 5 (5.4%) je imalo bjesnoću, a po jedan su ubijeni sjekirom, vilama ili od drugih vukova. Udio ženki među mrtvim vukovima je bio 56%, prosječna dob je bila 1.9 godina, a prosječna masa 31.4 kg. Posebno je analizirano posljednjih 10 godina (1986-1995) prije, te prvih 6 godina (1996-2001) nakon zakonske zaštite vrste (15. svibanj 1995.), a u kojim je razdobljima stradalo 30 odnosno 62 vuka. Godišnja smrtnost je porasla sa 3.0 prije zaštite na 10.3 nakon zaštite (3.4 puta). Ovaj porast pokazuje da se zakon ne provodi, kao i porast neprihvaćanja vuka od lokalnog stanovništva. Porast smrtnosti dijelom je povezan i s porastom populacije vuka te se čini da je veličina zabilježene smrtnosti podnošljiva za populaciju. Predlaže se prihvaćanje propisa koji bi omogućavali ograničeni i kontrolirani lov vukova. To bi moglo dovesti i do smanjenja mržnje prema vuku i posljedičnog smanjenja rizika za populaciju od nekontroliranog ilegalnog ubijanja

Uzroci smrtnosti vukova u Hrvatskoj u razdoblju od 1986. do 2001.

We recorded a total of 92 dead grey wolves (Canis lupus) in Croatia during the period1986-2001: 60 (65.2%) were shot, 18 (19.6%) died as a result of traffic accidents, while the cause of death of 6 (6.5%) wolves remained unknown, 5 (5.4%) suffered from rabies, and one each was killed by axe, by hay-fork, and by other wolves. Among dead wolves the share of females was 56%, mean age was 1.9 years, and the mean mass of adult wolves was 31.4 kg. We analyzed separately the 10 years (1986-1995) preceding, and the first 6 years (1996-2001) after the legal protection of the species (15 May 1995), when 30 and 62 wolves died, respectively. Annual mortality rose from 3.0 prior to protection to 10.3 after protection (3.4 times). This increase in mortality indicates no enforcement of the legal protection, as well as an increase in animosity by local people; it was also partly influenced by wolf population growth and it would appear that the recorded mortality is sustainable. We propose to adapt the legislation to permit the controlled hunting of wolves. This would in all likelihood lead to decreased animosity and would keep the wolf population safe from uncontrolled hunting.Od 1986. do 2001. zabilježena je smrt ukupno 92 siva vuka (Canis lupus) u Hrvatskoj: 60 (65.2%) su ustrijeljena, 18 (19.6%) je poginulo u prometnim nezgodama, za 6 (6.5%) vukova je uzrok smrti ostao nepoznat, 5 (5.4%) je imalo bjesnoću, a po jedan su ubijeni sjekirom, vilama ili od drugih vukova. Udio ženki među mrtvim vukovima je bio 56%, prosječna dob je bila 1.9 godina, a prosječna masa 31.4 kg. Posebno je analizirano posljednjih 10 godina (1986-1995) prije, te prvih 6 godina (1996-2001) nakon zakonske zaštite vrste (15. svibanj 1995.), a u kojim je razdobljima stradalo 30 odnosno 62 vuka. Godišnja smrtnost je porasla sa 3.0 prije zaštite na 10.3 nakon zaštite (3.4 puta). Ovaj porast pokazuje da se zakon ne provodi, kao i porast neprihvaćanja vuka od lokalnog stanovništva. Porast smrtnosti dijelom je povezan i s porastom populacije vuka te se čini da je veličina zabilježene smrtnosti podnošljiva za populaciju. Predlaže se prihvaćanje propisa koji bi omogućavali ograničeni i kontrolirani lov vukova. To bi moglo dovesti i do smanjenja mržnje prema vuku i posljedičnog smanjenja rizika za populaciju od nekontroliranog ilegalnog ubijanja

Pojavnost patoloških promjena na vučjim zubima (Canis lupus L.) u Hrvatskoj.

Skulls (N = 34) of gray wolves (Canis lupus) from Croatia were examined for acquired pathological changes of teeth. Skulls originated from wolves which had died due to various reasons in Croatia between 1997 and 2006. Age of examined animals ranged from 7 months to 8.5 years. Three skulls (8.9%) had pathological changes of teeth or alveolar bone. All dentitions with pathological changes belonged to females older than 2 years. Periodontitis, with changes in the alveolar bone, was determined on the alveolus of lower fourth premolar (P4) in two individuals and on the alveolus of the mandibular first molar (M1) in one specimen. A complicated crown-root fracture was found in two individuals. All caries lesions were found on premolars and molars. Caries was found on the upper jaw in one animal and on the lower jaw of another animal, while a third animal had it on both jaws. Pathological changes in the dentition of wolves in Croatia have not been previously recorded in Croatia. Data on pathological changes of wolves’ teeth contribute to the knowledge of biology and health of this species, especially on factors limiting longevity.Pregledane su 34 lubanje sivoga vuka (Canis lupus) i opisane stečene patološke promjene na zubima. Lubanje su potjecale od vukova koji su zbog različitih razloga stradali u Hrvatskoj od 1997. do 2006. godine. Dob tih vukova kretala se u rasponu od sedam mjeseci do osam i pol godina. Patološke promjene na alveolarnoj kosti zabilježene su na zubalima triju lubanja, odnosno na 8,8% pregledanih lubanja. Sve lubanje na čijim su zubalima nađene patološke promjene pripadale su ženkama starijima od dvije godine. U dvije jedinke opisan je periodontitis s promjenama u alveolarnoj kosti donjega četvrtoga pretkutnjaka (P4), a u jedne na gornjem prvom kutnjaku (M1). Potpuna fraktura zuba opisana je u dvije jedinke. U sve tri jedinke na pretkutnjacima i kutnjacima bio je prisutan i karijes i to na zubima gornje čeljusti kod jedne, donje čeljusti kod druge, a kod treće na zubima donje i gornje čeljusti. U hrvatskoj literaturi dosad nisu opisane patološke promjene na zubalu u ove vrste velike zvijeri. Podatci o patološkim promjenama na vučjim zubima pridonose boljem poznavanju biologije, osobito čimbenika koji utječu na životni vijek ove vrste

Kastracija europskog smeđeg medvjeda.

Facilities for captive holding of European brown bears (Ursus arctos) are usually limited in capacity and already filled. The brown bear is a protected species, reduction of free-living population is not allowed and protection of existing numbers is requested by international conventions. The best regulation of population in captivity is by orchiectomy because of surgical simplicity and efficiency. We achieved general anaesthesia by use of a combination of ketamine hydrochloride and xylazine hydrochloride applied intramuscularly in four treated males. Surgical procedure of orchiectomy was carried out by closed method using two skin incisions parallel to raphe scroti in one bear and prescrotal incision in the remaining 3 bears. Spermatic cord was ligated by a triple clamp technique. Skin incisions were sutured by simple interrupted pattern with absorbable suture material. Recovery from general anaesthesia was without side-effects after a mean duration of 172 min. Mean surgery time was 54 min. The surgical wounds healed “per primam”.Ograđeni prostori i utočišta za zbrinjavanje europskih smeđih medvjeda (Ursus arctos) ograničeni su površinom za prihvat napuštenih jedinki. Budući da je smeđi medvjed zaštićena vrsta, valja voditi brigu o broju jedinki njihove populacije. Najbolja kontrola broja jedinki u zatočeništvu je putem kirurškoga zahvata kastracije odnosno orhiektomije mužjaka zbog relativno jednostavne izvedbe zahvata. Orhiektomija četiriju mužjaka obavljena je u općoj anesteziji kombinacijom ketamin i ksilazin hidroklorida primijenjenih intramuskularno. U sva četiri medvjeda orhiektomija je obavljena zatvorenom metodom. U jednoga je primijenjena metoda dva kožna reza usporedno s mošnjičnim šavom, a u tri medvjeda preskrotalna metoda orhiektomije. U svih je primijenjena tehnika tri hemostata prilikom podvezivanja sjemenova užeta, a rane su bile sašivene resorptivnim koncem pojedinačnim čvorastim šavom. Buđenje iz anestezije bilo je uobičajenoga tijeka bez nuspojava. Zahvat je prosječno trajao 54 minute, a opća anestezija 171,5 minuta. Sve kirurške rane zacijelile su „per primam”, a oporavak je prošao bez nuspojava

Procjena izloženosti kadmiju, olovu i živi pri konzumaciji slobodne divljači u Hrvatskoj

Free-living game can be an important source of dietary cadmium and lead; the question is whether exposure to these two elements is such that it might cause adverse health effects in the consumers. The aim of this study was to estimate dietary exposure to cadmium, lead, and mercury from free-living big game (fallow deer, roe deer, red deer, wild boar, and brown bear), and to mercury from small game (pheasant and hare), hunted in Croatia from 1990 to 2012. The exposure assessment was based on available literature data and our own measurements of metal levels in the tissues of the game, by taking into account different consumption frequencies (four times a year, once a month and once a week). Exposure was expressed as percentage of (provisional) tolerable weekly intake [(P)TWI] values set by the European Food Safety Authority (EFSA). Consumption of game meat (0.002-0.5 % PTWI) and liver (0.005-6 % PTWI) assumed for the general population (four times a year) does not pose a health risk to consumers from the general population, nor does monthly (0.02-6 % PTWI) and weekly (0.1-24 % PTWI) consumption of game meat. However, because of the high percentage of free-living game liver and kidney samples exceeding the legislative limits for cadmium (2-99 %) and lead (1-82 %), people should keep the consumption of certain game species’ offal as low as possible. Children and pregnant and lactating women should avoid eating game offal altogether. Free-living game liver could be an important source of cadmium if consumed on a monthly basis (3-74 % TWI), and if consumed weekly (11-297 % TWI), it could even give rise to toxicological concern.Procjena izloženosti kadmiju, olovu i živi pri konzumaciji slobodne divljači u Hrvatskoj Slobodna divljač značajan je izvor kadmija i olova u prehrani ljudi te se nameće pitanje je li izloženost ovim metalima tolika da može štetno utjecati na zdravlje potrošača. Procijenili smo izloženost kadmiju, olovu i živi pri konzumaciji velike slobodne divljači (jelen lopatar, srna, obični jelen, divlja svinja i smeđi medvjed) te živi pri konzumaciji male divljači (fazan, zec) koja je ulovljena u Hrvatskoj između 1990. i 2012. godine. Procjena izloženosti temelji se na dostupnim literaturnim podacima i našim rezultatima mjerenja metala u tkivima divljači te različitoj učestalosti konzumacije (četiri puta godišnje, jedanput mjesečno, jedanput tjedno). Izloženost je prikazana kao postotak vrijednosti (privremeno) prihvatljivog tjednog unosa [(P)TWI] koju je postavila Europska agencija za sigurnost hrane (EFSA). Izloženost toksičnim metalima pri rijetkoj konzumaciji (pretpostavljena za opću populaciju) mesa (0,002-0,5 % PTWI) i jetre divljači (0,005-6 % PTWI) ne predstavlja zdravstveni rizik za potrošače, kao ni redovita (0,02-6 % PTWI) i česta (0,1-24 % PTWI) konzumacija mesa divljači. Preporuka je što više smanjiti konzumaciju iznutrica nekih vrsta divljači zbog visokog postotka uzoraka jetre, a posebno bubrega, koji prelaze zakonom propisane maksimalne razine kadmija (2-99 %) i olova (1-82 %). Djeca, trudnice i dojilje trebale bi izbjegavati konzumaciju iznutrica divljači. Jetra divljači može biti značajan dodatni izvor kadmija ako se redovito konzumira (3- 74 % PTWI), a čestom konzumacijom jetre (11-297 % PTWI) može se povećati rizik od štetnih učinaka na zdravlje

Rasprostranjenost i najmanja veličina populacije euroazijskog risa (Lynx lynx) u Hrvatskoj u razdoblju 2018.–2020.

Scientific data on distribution and abundance of endangered species are the foundation for their effective conservation and management. In this paper, we present results of the first scientifically – based estimation of lynx population size in Croatia. The goal of the study was to determine the area of lynx distribution and to estimate the minimum size of lynx population in Croatia in the period 2018 - 2020. To determine lynx distribution, 902 signs of lynx presence were collected in the period from the beginning of May 2018 until the end of April 2020. Out of those, 92.8% of lynx observations were categorized as C1, 2.8% as C2 and 4.4% as C3. Permanent lynx presence was confirmed in Primorsko – Goranska and Ličko – Senjska county, in southern part of Karlovac county and north-eastern part of Zadar county on the total surface of 7200 km2. For the minimum population size estimation, 804 camera trap photographs led to identification of 89 – 108 adult lynxes. Among 108 identified individuals there were 29 females, 22 males, while for 7 animals the sex was not determined. During the two reproductive seasons, we photographed 44 cubs in 25 litters. Future important steps in lynx population monitoring are correcting the deficiencies identified in this study and implementation of methodology that will allow us to use spatial capture recapture models for estimation of lynx abundance in Croatia.Znanstveni podaci o rasprostranjenosti i brojnosti temelj su za učinkovito upravljanje i zaštitu ugroženih populacija. U ovom radu predstavljamo rezultate prve znanstveno utemeljene procjene veličine populacije risa u Hrvatskoj. Cilj praćenja bio je utvrditi područje rasprostranjenosti risa i procijeniti najmanju veličinu populacije risa u Hrvatskoj u razdoblju 2018. - 2020. godine. U svrhu utvrđivanja rasprostranjenosti populacije, prikupljena su 902 znaka prisutnosti risa u razdoblju od 1. svibnja 2018. do 30. travnja 2020. Od toga je 92,8% podataka kategorizirano kao C1, 2,8% kao C2 i 4,4% C3. Trajna prisutnost risa potvrđena je u Primorsko-goranskoj i Ličko-senjskoj županiji, u južnom dijelu Karlovačke županije i sjeveroistočnom dijelu Zadarske županije, na ukupnoj površini od 7200 km2. Za procjenu minimalne veličine populacije, prikupljene su 804 fotografije s fotozamki tijekom obje sezone te je identificirano 89 do 108 odraslih životinja. Među 108 identificiranih jedinki, bilo je 29 ženki, 22 mužjaka i 57 životinja nepoznatog spola. Tijekom dvije sezone fotografirali smo 44 mladunca u 25 legla. Budući važni koraci u praćenju populacije risa su ispravljanje nedostataka utvrđenih u ovoj studiji, kako bi se omogućila procjena brojnosti korištenjem modela prostornog hvatanja i ponovnog hvatanja jedinki

Upotreba kontrolne regije mitohondrijske DNA za identifikaciju vrsta i razlikovanje vuka i psa iz Hrvatske.

Dogs worldwide share a single genetic origin from Asian wolves. While dog and wolf lineages are difficult to separate in terms of nuclear genes, mitochondrial lineages are clearly distinguishable for the two species, offering a good opportunity to evaluate the differences between them. Species identification from DNA is an important tool for wolf conservation in Croatia, and wolf - dog differentiation is necessary for forensic cases, wildlife management and scientific research. The goal of this paper was to provide a data set on Croatian dog and wolf mitochondrial DNA control region sequences, and to research if these sequences can be used as a reference for species identification. We analyzed 281 base pair sequences of the mitochondrial DNA (mtDNA) control region of 20 mixed breed dog blood samples, 91 grey wolf muscle samples and two muscle samples of wolf-like animals. We identified 12 dog and 4 wolf mtDNA control region haplotypes. None of the haplotypes were shared, confirming that mtDNA control region haplotypes can be used to discriminate between Croatian wolves and dogs, and to confirm the maternal ancestry of putative hybrids. The sequences of the two wolf-like animals clearly grouped into a dog cluster.Psi diljem svijeta imaju jedinstveno genetsko podrijetlo od azijskih vukova. Dok je vukove i pse teško razlikovati na temelju jezgrenih gena, mitohondrijska DNA jasno se razlikuje što daje dobru mogućnost za istraživanje razlika između tih dviju vrsta. Identifikacija vrste na temelju DNA važan je alat za zaštitu vuka u Hrvatskoj, a razlikovanje između vuka i psa prijeko je potrebno u forenzičkim slučajevima, upravljanju divljim životinjama i u znanstvenim istraživanjima. Cilj ovoga rada bio je dobiti podatke o sekvencijama mitohodrijske DNA vuka i psa iz Hrvatske te istražiti da li se te sekvencije mogu upotrijebiti kao referencija za razlikovanje vrsta. Analizirali smo sekvenciju kontrolne regije mitohondrijske DNA dugu 281 parova baza izdvojenu iz 20 uzoraka krvi pasa mješanaca, 91 uzorka mišića sivoga vuka i dva uzorka mišića životinja sličnih vuku. Pronašli smo 12 psećih i 4 vučja haplotipa kontrolnoga područja. Nijedan od haplotipova nije bio zajednički psima i vukovima, potvrđujući da se kontrolno područje mitohondrijske DNA može rabiti za razlikovanje pasa i vukova, te za određivanje majčinskih predaka mogućih hibrida. Sekvencije dviju životinja sličnih vuku jasno su pripadale psima

Upotreba kontrolne regije mitohondrijske DNA za identifikaciju vrsta i razlikovanje vuka i psa iz Hrvatske.

Dogs worldwide share a single genetic origin from Asian wolves. While dog and wolf lineages are difficult to separate in terms of nuclear genes, mitochondrial lineages are clearly distinguishable for the two species, offering a good opportunity to evaluate the differences between them. Species identification from DNA is an important tool for wolf conservation in Croatia, and wolf - dog differentiation is necessary for forensic cases, wildlife management and scientific research. The goal of this paper was to provide a data set on Croatian dog and wolf mitochondrial DNA control region sequences, and to research if these sequences can be used as a reference for species identification. We analyzed 281 base pair sequences of the mitochondrial DNA (mtDNA) control region of 20 mixed breed dog blood samples, 91 grey wolf muscle samples and two muscle samples of wolf-like animals. We identified 12 dog and 4 wolf mtDNA control region haplotypes. None of the haplotypes were shared, confirming that mtDNA control region haplotypes can be used to discriminate between Croatian wolves and dogs, and to confirm the maternal ancestry of putative hybrids. The sequences of the two wolf-like animals clearly grouped into a dog cluster.Psi diljem svijeta imaju jedinstveno genetsko podrijetlo od azijskih vukova. Dok je vukove i pse teško razlikovati na temelju jezgrenih gena, mitohondrijska DNA jasno se razlikuje što daje dobru mogućnost za istraživanje razlika između tih dviju vrsta. Identifikacija vrste na temelju DNA važan je alat za zaštitu vuka u Hrvatskoj, a razlikovanje između vuka i psa prijeko je potrebno u forenzičkim slučajevima, upravljanju divljim životinjama i u znanstvenim istraživanjima. Cilj ovoga rada bio je dobiti podatke o sekvencijama mitohodrijske DNA vuka i psa iz Hrvatske te istražiti da li se te sekvencije mogu upotrijebiti kao referencija za razlikovanje vrsta. Analizirali smo sekvenciju kontrolne regije mitohondrijske DNA dugu 281 parova baza izdvojenu iz 20 uzoraka krvi pasa mješanaca, 91 uzorka mišića sivoga vuka i dva uzorka mišića životinja sličnih vuku. Pronašli smo 12 psećih i 4 vučja haplotipa kontrolnoga područja. Nijedan od haplotipova nije bio zajednički psima i vukovima, potvrđujući da se kontrolno područje mitohondrijske DNA može rabiti za razlikovanje pasa i vukova, te za određivanje majčinskih predaka mogućih hibrida. Sekvencije dviju životinja sličnih vuku jasno su pripadale psima