Roman Gula

• Professor
• Professor (Full) at Polish Academy of Sciences

Advances in visual perceptual tasks have been mainly driven by the amount, and types, of annotations of large-scale datasets. Researchers have focused on fully-supervised settings to train models using offline epoch-based schemes. Despite the evident advancements, limitations and cost of manually annotated datasets have hindered further development...

Decades of research have shown that the coevolutionary arms race between avian brood parasites and their hosts can promote phenotypic diversification in hosts and brood parasites. However, relatively little is known about the role of brood parasitism in promoting phenotypic diversification of nestlings. We review field data collected over four deca...

We deployed two GPS collars and one innovative harness-mounted GPS backpack with Iridium or Globalstar satellite data transmission on feral pigs in mountain rainforest with deep valleys in New Caledonia during the hot wet season. Both collar and backpack with Iridium transmission achieved high success rates of locations and the rate increased with...

The little fire ant, Wasmannia auropunctata , is an invasive species known to negatively affect many native species in its introduced range. Here, we studied the effect of little fire ant presence on the biomass of soil fauna in rainforest of New Caledonia to assess if little fire ants have an impact on an endangered endemic flightless bird, the ka...

In ecological studies sampling must be stratified to ensure a sample population that best represents the entire population studied. Meta-analyses assessing global patterns should also use a stratified data structure to ensure unbiased results. We show that this is generally not the case, as individual studies are heavily biased toward the Norther...

Using offline training schemes, researchers have tackled the event segmentation problem by providing full or weak-supervision through manually annotated labels or self-supervised epoch-based training. Most works consider videos that are at most 10’s of minutes long. We present a self-supervised perceptual prediction framework capable of temporal ev...

[This corrects the article DOI: 10.1093/cz/zoab066.].

Nestling ejection is a rare type of host defence against brood parasitism compared to egg ejection. Theoretically, host defences at both egg and nestling stages could be based on similar underlying discrimination mechanisms but, due to the rarity of nestling ejector hosts, few studies have actually tested this hypothesis. We investigated egg and ne...

Nestling ejection is a rare type of host defence against brood parasitism compared to egg ejection. Theoretically, host defences at both egg and nestling stages could be based on similar underlying discrimination mechanisms but, due to the rarity of nestling ejector hosts, few studies have actually tested this hypothesis. We investigated egg and ne...

We investigated winter selection of resting sites by wolves in a commercial pine forest to test if roads, settlements , and type of forest influenced the resting behaviour of wolves during the day and at night. At the landscape scale, wolves selected resting sites that were farther from settlements, public roads and high-traffic forest roads than r...

Nest predation and avian brood parasitism are the main sources of nest failure in many passerine birds. Large predators threaten both brood and parents, whereas brood parasites pose only a danger to eggs or nestlings. The fan-tailed gerygone Gerygone flavolateralis from New Caledonia is subjected to high rates of nest predation by the New Caledonia...

The observation of rare behaviours can provide unexpected insights into the biology of a species. Here, we report new observations of unusual or rare behaviours by the Kagu Rhynochetos jubatus of New Caledonia, a flightless bird already known for many curious traits. We observed the broken-wing display, adoption of a chick by a neighbouring family...

W najnowszym numerze czasopisma Mammalian Biology publikujemy wyniki naszych badań nad wykorzystywaniem dróg leśnych przez wilki w Borach Dolnośląskich. Ten jeden z największych zwartych kompleksów leśnych w Polsce, jest w dużej części plantacją sosny, założoną przez niemieckich leśników w 19 wieku. Aby ułatwić sobie hodowlę i eksploatację lasu, po...

The wolf Canis lupus population occupying the lowlands of central Europe is divided into two management units: the Baltic population east of the Vistula river and the Central European population to the west. We re-evaluated arguments for this division in the context of the ongoing wolf recovery and its usefulness for wolf management in Poland. To d...

Temporal event segmentation of a long video into coherent events requires a high level understanding of activities' temporal features. The event segmentation problem has been tackled by researchers in an offline training scheme, either by providing full, or weak, supervision through manually annotated labels or by self-supervised epoch based traini...

Predation and brood parasitism are common reasons for nesting failure in passerine species and the additive impact by invasive species is a major conservation concern, particularly on tropical islands. Recognising the relative contribution of the different components of nesting failure rates is important to understand co‐evolutionary interactions w...

We investigated by snow tracking and GPS telemetry how wolves Canis lupus used a dense (4 km/km2) network of forest roads for travel and scent marking. Forty-six percent of wolf trails but only 4.6% of telemetry locations were on forest roads. Wolves used forest roads to travel fast and far across their home ranges but spent relatively little time...

Previous research reported a unique haematological profile in the flightless Kagu (Rhynochetos jubatus). To verify this, we analysed blood of eight wild and four captive Kagu. The haematological profiles of our captive birds resembled those of the previously studied captive Kagu. Haemoglobin concentration, mean corpuscular haemoglobin concentration...

Summary Between early May 2018 and end of April, we systematically recorded signs of wolf presence all over the monitored area (about 4500 km2) around the border between the Świętokrzyskie and Mazowieckie provinces. We monitored 11 forest complexes and recorded wolf presence in all of them. In 2018, we confirmed reproduction in 7 forest complexes....

Human dimensions are a critical part of large carnivore conservation. We investigated how the historical presence of wolves (Canis lupus) influences public attitudes toward the carnivore and its management in rural areas of Poland. From March 2016 to March 2017, we used a self-administered questionnaire to assess attitudes of rural residents (n = 2...

Obecnie wilki występują na około jednej piątej powierzchni Polski (60 000 km 2). Nie jest prowadzony regularny, ogólnokrajowy monitoring liczebności, ale jeśli założymy średnią wielkość terytoriów watah 150 km 2 i ich średnią liczebność 5 osobników, to otrzymana liczba 2000 wilków na pewno nie będzie przesadnie duża. Jednocześnie średnie zaludnieni...

Apart from a few well-studied examples, there is little information regarding the life history and ecological requirements of brood parasites and their hosts in most cuckoo–host systems, particularly in tropical areas. In New Caledonia, the Fan-tailed Gerygone Gerygone flavolateralis, is the exclusive host of the Shining Bronze-cuckoo, Chalcites lu...

Mimicry by avian brood parasites favours uniformity over variation within a breeding attempt as host defence against parasitism. In a cuckoo-host system from New Caledonia, the arms race resulted in both host (Gerygone flavolateralis) and parasite (Chalcites lucidus) having nestlings of two discrete skin colour phenotypes, bright and dark. In our s...

Polyandry has been studied in many species, especially birds [1]. Exclusively fraternal polyandry (several full or half-brothers with one unrelated female) is only known in human societies [2, 3], in which it is an important mechanism for limiting reproductive output [3] in association with scarce environmental resources [2]. However, the social or...

Extra-pair copulation can increase genetic diversity and offspring fitness. However, it may also increase intra-nest variability in avian hosts of brood parasites, which can decrease the discrimination ability of host parents towards the parasite. In New Caledonia, the Fan-tailed Gerygone (Gerygone flavolateralis), which is parasitized by the Shini...

Information on 141 samples of 127 Fan-tailed Gerygones (29 breeding pairs and their 69 offspring, 36 breeding attempts) in New Caledonia. ID: ID of individual, nest: nest number, breeding attempt: number of breeding attempt, status: parent or nestling, sex: F = female, M = male, habitat: type of habitat surrounding the nest, brood polymorphism: 0 =...

Rhynochetos orarius has been described from Holocene fossils as the sister species of the smaller extant Kagu Rhynochetos jubatus, a bird endemic to New Caledonia. However, we argue that there has never been evidence justifying the description of R. orarius. Additionally, for biogeographical reasons it seems unlikely that two Kagu species would hav...

Australia, New Zealand, New Guinea, Wallacea, and the islands of the Pacific Ocean collectively possess 42% of the world’s parrot species, including half of all Critically Endangered species. We used comparative methods to review the factors related to extinction risk of 167 extant and 5 extinct parrot species from this region, subsequently referre...

Selection of kill sites is an important part of predation. In human-modified habitats, anthropogenic landscape features may increase or decrease hunting efficiency of predators. We investigated which habitat attributes increase predation success in wolf Canis lupus hunting for ungulates in an intensively managed forest of western Poland. We used GP...

Krajowa strategia ochrony wilka warunkująca trwałość gatunku w Polsce

Positive range–abundance relationships in Indo-Pacific bird communities A B S T R A C T Reeve et al. (2016, Ecography, 39, 990–997) recently reported negative range–abun-dance relationships in Indo-Pacific bird communities and speculated that geographical isolation facilitates the evolution of broad-niched, small-ranged and abundant species. We tes...

To assess the effects of naturally occurring heavy metals on wild birds, we compared reproductive success and heavy metal contents in feathers of Kagu Rhynochetos jubatus living on ultramafic (rich in heavy metals) soils with those of Kagu living on non-ultramafic soils. From 2003 to 2016, we monitored breeding of 19 Kagu families by radio-tracking...

Combining radio-telemetry with direct observations, we followed 22 released juvenile captive-bred capercaillies throughout the day to assess if their seasonal and daily patterns of activity, movements, and diet are in accordance with published information on wild birds. Day length was the most important factor determining birds' mobility and activi...

The Crow Honeyeater (Gymnomyza aubryana) is a critically endangered bird, endemic to the main island of New Caledonia, but it is poorly known owing to its elusive nature. We conducted playback surveys to assess the distribution, habitat preferences and vocal activity of the species. Crow Honeyeaters responded well to playback, with response rates r...

Virulence of avian brood parasites can trigger a coevolutionary arms race, which favours rejection of parasitic eggs or chicks by host parents, and in turn leads to mimicry in parasite eggs or chicks [1-7]. The appearance of host offspring is critical to enable host parents to detect parasites. Thus, increasing accuracy of parasites’ mimicry can fa...

We developed a set of microsatellite markers for the fan-tailed gerygone (Gerygone flavolateralis), host of a brood parasite, the shining bronze-cuckoo (Chalcites lucidus). We used 454 pyro-sequencing to establish 17 polymorphic microsatellite markers. The number of alleles per locus ranged from 6 to 18, the expected heterozygosity from 0.328 to 0....

A new mother-assisted rearing and release technique (" born to be free ") reduces the exploratory movements and increases survival of young capercaillies Abstract We compared the mobility and survival rates of two groups of young capercaillies that were reared and released by different methods. One group consisted of 21 radio-tracked chicks that we...

Invasive species usually go through a period of reduced genetic variability due to a bottleneck. The genetic constitution of an invading population should therefore reflect the time since invasion and the number of introduction events. We studied genetic population structure of three rat species occurring sympatrically on the island of Futuna (46 k...

We assessed heavy metal concentrations in feathers of 38 Kagus Rhynochetos jubatus living on ultramafic soils in New Caledonia. Concentrations of heavy metals in down feathers were similar to concentrations in shafts of primary or secondary feathers, whereas the concentrations in vanes were much higher, indicating that concentrations in down feathe...

In Europe, brown bear Ursus arctos habitats frequently overlap with human settlements and infrastructure. We tested whether anthropogenic structures played an important role in habitat selection by brown bears in the Bieszczady Mountains, Poland. We analysed 668 signs of brown bear presence recorded during 6 counts along 246 km of transects (total...

Standardised surveys are essential for monitoring populations and identifying areas that are critical for conservation. With the aim of developing a standardised method of surveying parrots in the rainforests of New Caledonia, we used distance sampling to estimate densities of New Caledonian Parakeets (Cyanoramphus saisseti), Horned Parakeets (Euny...

Individual studies in wildlife science are indicative rather than conclusive. Although multiple studies can be meta-analyzed in such a way that scientific hypotheses can be tested, robust meta-analyses are often difficult or impossible if variables of interest are not measured in a uniform manner. We hypothesized that measurements, even of basic an...

Knowing the distribution and abundance of species is critical for conservation, yet field surveys are often limited in their spatial extent. In this study, we use ecological niche models to infer the current and future distribution of New Caledonian Parakeets (Cyanoramphus saisseti), Horned Parakeets (Eunymphicus cornutus), and Ouvea Parakeets (Eun...

Human disturbance is thought to be a major source of stress for animals but breeding status, social interactions and food availability are also potential sources. Long-lasting stress may adversely affect the fitness of animals and for that reason the evaluation of stressors is important for conservation of threatened species. The aim of our study w...

Rats are major reservoirs of leptospirosis and considered as a main threat to biodiversity. A recent introduction of Rattus rattus to the island of Futuna (Western Polynesia) provided the opportunity to test if a possible change in species composition of rat populations would increase the risk of leptospirosis to humans. We trapped rodents on Walli...

We used 454 pyro-sequencing to establish microsatellite markers for the endangered Kagu (Rhynochetos jubatus), a bird endemic to New Caledonia. We screened 52,583 reads to identify 60 microsatellites candidates and established 12 polymorphic loci. The number of alleles per locus ranged from 2 to 15, the observed heterozygosity from 0.046 to 0.818,...

ABSTRACT Noninvasive genetic monitoring of animal populations has become a widely used method in animal conservation and wildlife management due to its known advantages in sample availability of endangered or elusive species. A variety of methods have been suggested to overcome the difficulties of collecting reliable genetic data despite poor DNA q...

We report 7years of experience with an inexpensive and reliable continuous audio/video recording system. The main components of the system are commercial, infrared illuminator surveillance cameras, mini microphones and portable digital video recorders, powered by deep cycle lead-acid batteries. We used the system for monitoring 41 broods of four en...

In November 2007 and November 2008, we conducted a bird and mammal survey on Wallis and Futuna. We found two non-native bird species on Wallis: the Common Myna (Acridotheres tristis) and the Chestnut-breasted Munia (Lonchura castaneothorax), and one on Futuna: the Jungle Myna (Acridotheres fuscus). We also recorded Black Rats (Rattus rattus) on Fut...

Daily defecation rate is an important variable in density estimation of African (Loxodonta qfricana) and Asian (Elephas maximus) elephants. However, there has been no attempt to construct a general model that predicts defecation rates. By comparing 16 published studies, we found that annual and seasonal daily defecation rates increased with annual...

We provide evidence for cooperative breeding in two endemic parrot species of New Caledonia, the New Caledonian Parakeet (Cyanoramphus saisseti) and the Horned Parakeet (Eunymphicus cornutus). We intensively monitored 11 breeding attempts in two nests of New Caledonian Parakeets over 5 years, and noticed that two males of different size fed the fem...

In the course of their maturation, most young wolves leave their natal pack and disperse in search for mating partners, improved food availability and new territories. We investigated whether this dispersal is affected by anthropogenic infrastructure in a 5,000km² area of the eastern region of the Polish Carpathian Mountains occupied by wolves. A r...

Birds that live in family groups and cooperatively defend the family's territory are currently recognized as cooperative breeders only if helpers assist with chick rearing. We observed breeding Kagus (Rhynochetos jubatus) and video-monitored nests to determine whether help with feeding or family size affected their reproductive success. During >5,5...

Wolf activity varies considerably among differentstudies that explained activity patterns by factors suchas human activity, breeding status or prey availability(Fancy and Ballard 1995; Vila` et al. 1995; Ciucci et al.1997; Theuerkauf et al. 2003; Kusak et al. 2005; Chavezand Gese 2006; Theuerkauf et al. 2007). However, it islikely that the high var...

We studied the activity and movements of a male and a female wolf during breeding in the Bieszczady Mountains, Poland. The female was less active and mobile and on average closer to the den than the male. The male was less active and mobile when the pack size was seven compared to a year when the pack consisted only of the breeding pair. We conclud...

Legal protection of wolves (Canis lupus) in Poland was implemented in 1998 after 23years of management as a game species. Wolves occurring in Poland were interconnected with larger populations in the Carpathian Mountains and Belarus, Baltic States and Russia, stable in numbers, and were not considered endangered before the change in legal status af...

Abstract As wolves (Canis lupus) recover in Poland, their depredation on domestic animals is increasing, as have conflicts between wolves and farmers. From 1998 to 2004, I investigated spatial and temporal patterns of 591 verified incidents of wolf depredation in the eastern part of the Polish Carpathian Mountains. The wolf population I surveyed co...

until recently. The radio tracked wolves of three packs moved throughout the day with one major peak around dawn. Wolves avoided the area around main public roads more at night (up to a distance of 1.5 km) than in the day (up to 0.5 km). Wolves avoided a 0.5-km area around secondary public roads and paved forest roads both at night and in the day b...

Noninvasive samples are of increasing importance to study wild populations. In this study, we investigate the applicability of urine samples as the sole source of DNA for routine noninvasive genetic monitoring of wildlife using wolves (Canis lupus) as an example. Within the scope of a long-term wolf population survey, we collected during winter sno...

A population of grey wolvesCanis lupus Linnaeus, 1758 inhabiting Białowieża Primeval Forest (BPF) on the Polish-Belarussian border has recovered after near extermination in the 1970s. Currently, it is intensively hunted in the Belarussian part of BPF and protected in the Polish part. We used a combination of molecular analysis, radiotracking, and f...

Sex, age, bone marrow fat (BMF) content, degree of carcass utilisation and terrain features were analysed for 118 ungulates killed by wolves Canis lupus in the Bieszczady Mountains, Poland, during the winters of 1992-1995 to assess the influence of snow depth on the wolves' predation patterns. In Bieszczady, the snow conditions during the study per...

Knowledge about the impact of human activity on the behavior of wolves (Canis lupus) is important to pre- dict habitats suitable for wolf recolonization and for planning management zones. We tested the hypothesis that wolves live spatiotemporally segregated from humans. From 1994 to 1999, we radiotracked 11 wolves in 4 packs and monitored human act...

We studied the influence of human activity, hunting of prey by wolves, reproduction, and weather conditions on daily patterns and duration of activity of 11 radiotracked wolves (Canis lupus) in the Białowieża Forest (Poland) from 1994 to 1999. On average, wolves were active 45.2% ± 0.9 SE of the time and traveled 0.92 ± 0.05 km/h. The mean length o...

were active 45.2% 6 0.9 SE of the time and traveled 0.92 6 0.05 km/h. The mean length of activity bouts was 0.76 6 0.05 h, whereas inactivity bouts averaged 1.02 6 0.07 h. Wolves were active throughout the day, but their activity peaked at dawn and dusk, which coincided with periods when they killed most prey. Periods of reproduction and high tem-...

It is important for the management of recol-onizing wolves (Canis lupus) in Europe to understand the wolves' reactions to human activity. The aim of this study was to find out whether human activity affects the daily movement patterns of wolves. During 3 winters (1996-1999), we radiotracked 6 female wolves and monitored the pattern of human activit...

The present status and main threats to the future viability of brown bears (Ursus arctos) in Poland were evaluated. The remaining 80- 90 individuals are found only in the Carpathian Mountains and feed on a variety natural foods, but occasionally kill livestock and cause damage to beehives. Several factors including poaching, local development, logg...

1992. The autum n and spring diet of brown bear Ursus arctos in the Bieszczady M ountains of Poland. Acta theriol. 37: 339 -3 44 . The diet of brown bear Ursus arclos Linnaeus, 1758 in the autum n of 1990 and the spring of 1991 was studied by the analysis of faeces contents (46 sam ples, 23 from au tu m n and 23 from spring). Based on frequency of...