Wolf Behavior : Reproductive, Social, Intelligent

Abstract
Since the return of the grey wolf (Canis lupus) to Germany in the late 1990s, the Federal Documentation and Consultation Centre on Wolves has been conducting nationwide population monitoring, with animals found dead representing an important source of information. In addition to the standardized necropsy at the Leibniz Institute for Zoo and Wildlife Research, 182 male wolves were examined for their reproductive status between 2020 and 2024. Testis mass was measured and spermatogenic activity was determined by flow cytometric ploidy analyses of dissociated testis tissue and the presence of epididymal sperm. These reproductive parameters were evaluated with regard to age class (juvenile, subadult, adult) and month of death (seasonality). Deciphering seasonality in subadult and adult males showed that haploid cells and epididymal sperm are not only present during the mating season (January to March) but also before (October to December), as meiotic activity already begins in late summer. Almost no spermatogenic activity was detected between May and August. While the body mass of (sub)adult males remained relatively constant throughout the year, testis/body mass ratio increased with spermatogenic activity. Spermatogenic activity already occurred in juvenile males, but it was delayed, and the average level of reproductive parameters increased from juvenile to subadult males, reaching their maximum in adult wolves. Sperm production varied greatly among juveniles and was related to their body and testis mass. Basic sexual maturity was only reached at a body mass of more than 25 kg and a testis mass of more than 5 g.You

Abstract

Territorial behaviour in wolves (Canis lupus) plays a central role in shaping social dynamics, resource access, and population structure. Although wolf packs are typically territorial, spatial overlap between neighbouring territories does occur. Understanding the drivers of these overlaps provides insight into wolf social organisation, resource competition, inter-pack conflict risk, and individual movement between packs, factors that collectively influence broader population dynamics.
This study investigates spatial overlap among neighbouring wolf territories in Scandinavia using GPS collar data, genetic relatedness, and spatial modelling. I applied Generalized Additive Models (GAMs) to model the size of spatial overlap (km²) between territorial pairs as a function of several covariates: (1) normalized difference in territory size, (2) dyadic social status (scent-marking pair vs. family group combinations), (3) genetic relatedness between alpha males and between alpha females, and (4) time since territory establishment. These covariates were selected based on ecological relevance and were derived from long-term monitoring data and pedigree records.
Spatial overlap was best predicted by territory size differences, dyadic social status, and female genetic relatedness. Overlap increased with greater disparity in territory size and was higher between scent-marking pairs compared to family groups. Female relatedness showed a non-linear effect; overlap increased with initial relatedness but declined beyond a threshold. Male relatedness had no notable effect.
Complementary Generalized Linear Mixed Models (GLMMs) were used to assess how wolves used different territorial zones (core, peripheral, overlap). These models revealed that wolves generally spent less time in overlap zones, with scent-marking pairs using these areas more than family groups. Additionally, territory age (defined as years since establishment) was negatively associated with overlap use, suggesting that older territories exhibit greater spatial stability and reduced inter-pack intrusion.
Together, these findings highlight the importance of social structure, territorial history, and genetic relationships in shaping spatial interactions among wolf packs. Understanding these drivers is essential for interpreting wolf space use in multi-use landscapes and has consequences for the management including monitoring of the population.

Abstract

The use of space by large carnivores is driven by the need to access essential resources and avoid human disturbances, resulting in spatiotemporal avoidance behaviours due to anthropogenic pressure. The Carpathian mountain range is one of Europe’s largest and less human-dominated stronghold for wolves, yet it remains significantly understudied. In this study, we systematically surveyed signs of wolf presence in the Slovak Western Carpathians to assess habitat selection across 3 periods with biological significance (mating, pup-rearing and non-breeding). We employed a second-order Resource Selection Functions and used-available design, i.e., relative selection, to provide the first available information on wolf habitat selection in the Carpathians and determine the influence of several environmental and anthropogenic variables, including road density and wolf harvest. Our results show significant seasonal variations in wolf habitat selection while consistently avoiding humans, except for areas with dense forest canopy. The avoidance of humans was particularly pronounced when wolves were subjected to human hunting pressure, showing decreased selection strength and a marked tendency to choose areas with minimal human activity to reduce likelihood of detection. Finally, we provided spatially explicit predictive models of wolf seasonal resource selection to support the identification of areas of significance for adequate wolf management. Our study provides valuable insights for efficient and cost-effective management decisions to limit the effect of anthropogenic pressures on wolves, in order to reduce disturbance, mortality risk, and enhance breeding success.

Flexed-leg urination (FLU) in female Gray Wolves (Canis lupus) has been little studied in the wild. Captive females in packs do not exhibit FLU unless they are both mature and dominant to an associate female, but these characteristics have not been confirmed in free-ranging wolves. We present observations of wolves in Yellowstone National Park that accord with those of wolves in captivity, extend our knowledge of FLU in Gray Wolf, pose additional questions about it, and suggest new areas of study to better understand it.

Some animals use humanmade objects for building and constructing nests or shelter and even for play. Gray wolves (Canis lupus) gather and use humanmade objects discovered in their natural environment. Gathering humanmade objects is a peculiar behavior particularly when there is no immediately apparent benefit to survival or reproduction. I opportunistically documented 46 different types of humanmade objects with plastic bottles and aluminum cans being the most common items found at wolf pup-rearing sites. Many objects were made of materials that appeared suitable to alleviate pain in teething pups. For some objects, however, it was not immediately obvious that they would alleviate teething pain due to their unpliable material. Additionally, such objects were quite rare in wolves’ natural environment although it was not uncommon to find them at pup-rearing sites. Rare humanmade objects may provide a novelty that stimulates pups more than common objects. I hypothesize that objects used by wolf pups 1) alleviate pain from teething, and 2) provide adults respite from energetic pups. The latter is an important distinction because it implies the benefit of object play is to the adults and not the pups per se. Gathering novel objects that occupy energetic and hungry pups may influence the overall ability of social carnivores to leave young unattended while they hunt, to rest upon their return, and ultimately rear young successfully.