"The Yellowstone Wolf Project reporting that at the end of 2018, some 80 Wolves exist in Yellowstone National Park, within the average 83-108 population count over the most recent 2009-17 period".............."Wolves preyed on 95 elk (62.9%), 25 bison (16.6%), 11 mule deer (7.3%), 3 deer of unknown species (2.0%), 2 coyotes (3.0%), 2 pronghorn (1.3%), 1 grizzly bear (0.6%), 1 mountain lion (0.6%), and 11 unidentifiabled animals (7.3%)".........."The composition of wolf-killed elk was: 22.1% calves, 6.3% yearlings, 22.1% adults"............."No major disease epidemic adversely impacted Yellowstone Wolves in 2018"

https://tinyurl.com/pr-wolf-report

The 2018 Yellowstone Wolf Project Report


There were at least 80 wolves in 9 packs (7 breeding pairs) living primarily in Yellowstone National Park (YNP) at the end of December 2018. Overall, wolf numbers uctuated little from 2009 to 2017 (83-108 wolves) but dropped slightly this year, particularly in the interior of Yellowstone. It is worth noting that there were two packs (Snake River and Huckleberry) which occasionally utilized the southern portion of Yellowstone but were not included in the population estimate (see wolf pack summaries). Breeding pairs (de ned as an adult male and an adult female with at least two pups that survive through the end of the year) remained consistent with the historical average. Pack size in 2018 ranged from 3 to 19, averaging 8.7 in size. Park-wide, 24 pups survived to year end, split between northern Yellowstone (12) and the interior (12) of the Park.

Pup Survival

Each year sta attempt to establish early pup counts at dens by either observing wolves from the ground through spotting scopes or, more often, taking photos of the den area during tracking ights. Early pup counts for each pack generally be- gin in late May and early June when pups are more consis- tently outside of den holes. For some packs whose densites are unknown or di cult to observe, we do not get pup counts until the pups are moved to a rendezvous site in late summer or early fall. This year the Wolf Project documented at least 38 pups born to eight di erent packs. Once again we were able to get exceptionally early counts from the Junction Butte pack ( rst pup sighting was May 7th of two pups only ~15 days old) but most pup counts were much later in the year. Both the Junction Butte (11 pups from 3 litters) and Wapiti Lake (7 pups from 2 litters) packs produced multiple litters. Of the minimum 38 pups produced in all packs, 24 (63.2%) pups survived to the end of the year.

  Wolf-Prey Relationships

Project sta detected 151 kills that were defnitely, probably, or possibly made by wolves in 2018: 95 elk (62.9%), 25 bison (16.6%), 11 mule deer (7.3%), 3 deer of unknown species (2.0%), 2 coyotes (3.0%), 2 pronghorn (1.3%), 1 grizzly bear (0.6%), 1 mountain lion (0.6%), and 11 unidenti ed animals (7.3%). The composition of wolf-killed elk was: 22.1% calves, 6.3% yearlings, 22.1% adult females, 37.9% adult males, 3.2% adults of unknown sex, and 8.4% of unknown sex and age. Wolf predation was monitored intensively for two months of the year – one month in early winter (mid-November to mid-December), one month in late winter (March). In re- cent years predation studies have included three months in spring-summer (May-July) but that study was not done in 2018. The type of prey killed by wolves varied by time period, but consisted primarily of elk. 

Disease
There was no evidence of any major disease mortality. Mange was present in several coyotes and foxes in or near the park boundary but was not recorded in any wolves in 2018.