Vocabulary S-T

A-B / C-D / E-F / G-H / I-J / K-L / M-N / O-P / Q-R / S-T / U-V / W-X / Y-Z


Scale Invariance
In physics, mathematics and statistics, is a feature of objects or laws that do not change if scales of length, energy, or other variables, are multiplied by a common factor, thus represent a universality.

The wolves of Isle Royale display scale‐invariant satiation and ratio‐dependent predation on moose. Jost C, Devulder G, Vucetich JA, Peterson RO, Arditi R. Journal of Animal Ecology. 2005 Sep

SCALP Criteria (Europe)
SCALP stands for “Status and Conservation of the Alpine Lynx Population.” Monitering criteria were developed for the Lynx transnational project and then developed and adapted further for the wolf re-population in Germany.

Secondary Recovery Zone
This national forest land next to the Primary Recovery Zone is an area where wolves are allowed to disperse. Wolves with experience in the wild, as well as those born in the wild, may also be moved to and released in this zone.

Mexican Gray Wolf Environmental Impact Statement

Sexual Dimorphism
The condition where the two sexes of the same species exhibit different characteristics beyond the differences in their sexual organs. The condition occurs in many animals and some plants. Differences may include secondary sex characteristics, size, weight, color, markings, and may also include behavioral and cognitive differences.

Sexual dimorphism in wolves (Canis lupus) of the Keewatin District, Northwest territories, Canada. Hillis TL, Mallory FF. Canadian Journal of Zoology. 1996 Apr

Single-nucleotide Polymorphism,
Abbreviated to SNP (/snɪp/; plural /snɪps/), is a variation in a single nucleotide that occurs at a specific position in the genome, where each variation is present to some appreciable degree within a population

Single Nucleotide Polymorphism (SNP) Variation of Wolves (Canis lupus) in Southeast Alaska and Comparison with Wolves, Dogs, and Coyotes in North America
MA Cronin, A Cánovas, DL Bannasch… – Journal of …, 2014

Snowpack Water Equivalent Intensity (SWEI)
Snow Water Equivalent (SWE) is a common snowpack measurement. It is the amount of water contained within the snowpack. It can be thought of as the depth of water that would theoretically result if you melted the entire snowpack instantaneously. Courtesy of

Soft release
The release of wolves to the wild from a temporary pen, where they have been held for a period of time to acclimate to the area of the release. The duration of acclimation may vary from several weeks to several months.

“A technique often included in reintroductions to try and improve success by providing animals with an easier or more gradual transition to the wild. Measures include e.g. training animals to recognise predators, providing supplementary food after release, or temporarily containing individuals in a protective enclosure at the release site, so they can gradually adjust new conditions before release” Courtesy of

S.O.P. (Standard Operating Procedure)
The purpose of an SOP is to standardize how a particular task, process, or situation is handled. This is important to make sure that there is consistency in how different issues surrounding the management of Mexican wolves in the wild are conducted. They are also important to ensure that the agencies and their staff are in compliance with law, policy, etc. Lastly, the SOP’s help ensure that actions are conducted safely, under the appropriate authority, and that data are collected and analyzed consistently. For a complete list of the SOP’s that relate to the Mexican gray wolf, see SOP.

Spatially explicit capture–recapture
“A set of methods for studying marked animals distributed in space. Data comprise the locations of detectors (traps, searched areas, etc. described in an object of class ‘traps’), and the detection histories of individually marked animals. Individual histories are stored in an object of class ‘capthist’ that includes the relevant ‘traps’ object.” (Courtesy of)

Toward reliable population estimates of wolves by combining spatial capture-recapture models and non-invasive DNA monitoring. García, E.J., Godinho, R., López-Bao, J.V., Lema, F.J. and Pacheco, C., 2018.

A non-technical overview of spatially explicit capture–recapture models. Borchers D. Journal of Ornithology. 2012 Feb

Spatiotemporal Trophic Mismatch
Differential phenological responses to climate among species disrupting trophic interactions and important life-history events (i.e.migration, breeding).

“In highly seasonal environments, timing of breeding of organisms is typically set to coincide with the period of highest resource availability. However, breeding phenology may not change at a rate sufficient to keep up with rapid changes in the environment in the wake of climate change. The lack of synchrony between the phenology of consumers and that of their resources can lead to a phenomenon called trophic mismatch.”

Doiron M, Gauthier G, Lévesque E. Trophic mismatch and its effects on the growth of young in an Arctic herbivore. Global Change Biology. 2015 Dec

Stand (Forest) –
A contiguous community of trees sufficiently uniform in composition, structure, age ,size, class, distribution, spatial arrangement, site quality, condition, or location to distinguish it from adjacent communities.

Nyland, Ralph D. (2007). Silviculture: concepts and applications, 2nd ed. Prospect Heights: Waveland Press.

Stand Initiation Stage (Stand succession)
“Stand initiation, the first stage of forest succession or open shrub stage: The open condition after disturbance allows colonization by a variety of plants. Forest floor herbs, shrubs and seedlings may have survived the disturbance; new individuals and pioneer species invade over a period of several years. This is generally a period of diverse species composition. Planted seedlings are part of this stage.”

Forest Measurements: An Applied Approach
Author: Joan DeYoung, Creative Commons Attributions

Stem Exclusion Stage (Stand succession) –
“Nevertheless, naturally regenerating conifers begin to form a dense canopy 20 to 30 years after logging that shades out understory plants (Alaback 1982). Eventually young seral stands enter a stem exclusion stage in which the dense canopy of even-aged young trees almost completely eliminates forage plants, creating unproductive year-round habitat conditions that may last more than 150 years. “

Person DK, Brinkman TJ. Succession debt and roads. North Pacific Temperate Rainforests: Ecology and Conservation. 2017 May

A randomly determined process; having a random probability distribution or pattern that may be analyzed statistically but may not be predicted precisely.

Subnivean Zone or Climate
The area between the surface of the ground and the bottom of the snowpack. This is the environment of many hibernal animals, as it provides insulation and protection from predators. The subnivean climate is formed by three different types of snow metamorphosis: destructive metamorphosis, which begins when snow falls; constructive metamorphosis, the movement of water vapor to the surface of the snowpack; and melt metamorphosis, the melting/sublimation of snow to water vapor and its refreezing in the snowpack. These three types of metamorphosis transform individual snowflakes into ice crystals and create spaces under the snow where small animals can move. Read more

“Succession Debt” –
“The inexorable process of forest succession following clear-cut logging in the North Pacific rainforest transitions through several distinct stages with varying effects on wildlife, but it ultimately reaches a condition (corresponding to the stem exclusion stage) that is largely unproductive for many species (Alback, 1982; Shoen et al 1988; Alback et al, this volume chapter 4). We refer to circumstances affecting wildlife populations resulting from that chain of events as succession debt. (Person 2001). Short term economic and social benefits of industrial harvesting of timber will be paid for by long term ecological consequences resulting from patterns and processes of forest succession and roads.”

Person DK, Brinkman TJ. Succession debt and roads. North Pacific Temperate Rainforests: Ecology and Conservation. 2017 May 1:143.

Succession (Forest)
“Forest succession in its traditional sense implies two important features that resist direct examination. First, classical definitions of forest succes-sion generally connote directional changes in species composition and in community structure through time. Following a major disturbance, a directional succession of tree species in our temperate forests may involve 200 (Oosting 1942), 400 (McAndrews 1976), or even 1000 years (Franklin and Hemstrom Chapter 14). There is hardly the opportunity to observe the direction, let alone the species succession, that occurs within our lifetime.”

Solomon AM, West DC, Solomon JA. Simulating the role of climate change and species immigration in forest succession. InForest succession 1981

SSP (Species Survival Plan)
[Mexican Gray Wolves]
The SSP began in 1981 as a cooperative population management and conservation program for selected species in zoos and aquariums in North America. Each SSP manages the breeding of a species in order to maintain a healthy and self-sustaining captive population that is both genetically perse and demographically stable. SSPs also participate in a variety of other cooperative conservation activities, such as research, public education, reintroduction and field projects. For more information, see SSP.

[Mexican Gray Wolves]
This studbook is a compilation of the vital records of the entire historic captive population of the Mexican gray wolf subspecies. Included are all the births, deaths, and transfers that have occurred in the history of the subspecies, as well as the family lineages.

In biology and ecology, two species or populations are considered sympatric when they exist in the same geographic area and thus regularly encounter one another.

Husseman JS, Murray DL, Power G, Mack C, Wenger CR, Quigley H. Assessing differential prey selection patterns between two sympatric large carnivores. Oikos. 2003 Jun

Systems Ecology
Systems ecology is an interdisciplinary field of ecology, a subset of Earth system science, that takes a holistic approach to the study of ecological systems, especially ecosystems. Systems ecology can be seen as an application of general systems theory to ecology.

A type of intraspecific or interspecific competition that results from the behavioral exclusion of others from a specific space that is defended as territory. This well-defined behavior is exhibited through songs and calls, intimidation behavior, attack and chase, and marking with scents.
With wolves, territorialiry is best described as intraspecific interference competition.

Any species which is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range.

Hervieux D, Hebblewhite M, Stepnisky D, Bacon M, Boutin S. Managing wolves (Canis lupus) to recover threatened woodland caribou (Rangifer tarandus caribou) in Alberta. Canadian Journal of Zoology. 2014 Nov