Derek Edward Lee

• PhD Biology, MS Wildlife Management, BA Cultural Anthropology
• Principal Scientist at Wild Nature Institute

Remarkable variation in animal colour patterns is often shaped by heterogeneous selection, reflecting adaptation to variable environmental conditions. However, the adaptive functions of patterns and drivers of selection remain poorly understood. Shape and size of colour patterns may help with thermoregulation and thus be altered by temperature anom...

Responses of natural populations to climate change are driven by how multiple climatic and biotic factors affect survival and reproduction, and ultimately shape population dynamics. Yet, we lack a general understanding of the role of such mechanisms in moderating climate-change impacts across different species. Here, we synthesize how the joint eff...

In East Africa, community-based conservation models (CBCMs) have been established to support the conservation of wildlife in fragmented landscapes like the Tarangire Ecosystem, Tanzania. To assess how different management approaches maintained large herbivore populations, we conducted line distance surveys and estimated seasonal densities of elepha...

Giraffes exhibit a large sexual dimorphism in body size. Whether sexual dimorphisms also exist in body proportions of the axial and appendicular skeleton has been debated, particularly regarding the giraffe’s iconic long neck. We examined the anatomical proportions of the neck, forelegs, hindlegs, and body trunk of the Masai giraffe ( G. tippelskir...

Many ungulate species in Africa range in habitats that vary in type and quality over space and time, but ongoing environmental change is substantially altering their habitats. Identifying key environmental variables that regulate ungulate population densities can guide management actions for effective conservation. We studied the local population d...

This study shows that effective wildlife law enforcement which protects giraffes from illegal hunting is the best way to keep giraffe populations healthy and thriving.

The Masai giraffe has experienced a population decline from 70,000 to 35,000 in the past three decades and was declared an endangered subspecies by the IUCN in 2019. The remaining number of Masai giraffe are geographically separated by the steep cliffs of the Gregory Rift escarpments (GRE) in Tanzania and Kenya dividing them into two populations, o...

With the rapid pace of global warming, there is an urgent need to understand survival responses to climate, particularly for large mammals that are already experiencing population declines associated with anthropogenic pressures such as poaching and habitat loss. We tested hypotheses about the interactive effects of local climatic anomalies (variat...

Many ungulate species in Africa range in habitats that vary in type and quality over space and time, but ongoing environmental change is substantially altering their habitats. Identifying key environmental variables that regulate ungulate population densities can guide management actions for effective conservation. We studied the local population d...

Giraffes exhibit a large sexual dimorphism in stature and body mass. Whether sexual dimorphisms also exist in relative body proportions of the axial and appendicular skeleton has been debated, particularly regarding the evolution of the giraffe’s iconic long neck. We measured and analyzed the relative anatomical proportions of the neck, legs, and b...

Biofluorescence of mammalian pelage may serve to hide prey from predators sensitive to ultraviolet radiation, among other potential functions. To date biofluorescence has been documented in nocturnal-crepuscular and fossorial mammals that are active under low-light conditions. Giraffes are primarily diurnal, but biofluorescent pelage might offer ca...

A population of Masai giraffes (Giraffa camelopardalis tippelskirchi) occurs in Arusha National Park (ANP), which is not part of the regular Tanzanian national wildlife monitoring scheme. Urban development of Arusha city and agricultural expansion have contributed to the increasing isolation of ANP from other protected areas in northern Tanzania. T...

Evolution of the giraffe neck was originally proposed as an adaptation to foraging at the tops of acacia trees, but this theory has been overshadowed by the “necks for sex” hypothesis that proposed that long necks evolved via sexual selection associated with male neck fighting. The necks for sex hypothesis predicted that males would have longer nec...

The Masai giraffe has experienced a population decline from 70,000 to 35,000 in the past three decades and was declared an endangered subspecies by the IUCN in 2019. The remaining population is divided into smaller subpopulations dispersed west and east of the Gregory Rift Valley (GRV) in Tanzania, Kenya, and Zambia. The steep escarpments of the GR...

Individual-based studies where animals are monitored through space and time enable explorations of ecology, demography, evolutionary biology, movements, and behavior. Here, we review 70 years of research on an endangered African herbivore, the giraffe, based on individual spot pattern recognition, and profile an example of a long-term photographic...

Animal color pattern is a phenotypic trait that may mediate assortative mixing (also known as homophily), whereby similar looking individuals have stronger social associations. Masai giraffe (Giraffa camelopardalis tippelskirchi) coat spot patterns show high variation and some spot traits appear to be heritable. Giraffes also have high visual acuit...

Northern elephant seals Mirounga angustirostris were extirpated from California in the 19 th century, and only in recent decades have they recolonized. A key demographic parameter underlying population viability is the survival of pups, from birth to weaning. We evaluated local factors acting directly on pup survival prior to weaning and basin-wide...

Habitat selection is a dynamic biological process where species respond to spatiotemporal variation in resource availability. The resulting distribution patterns can be detected as presence–absence or heterogeneity in abundance and indicate habitat preferences based on environmental correlations at multiple scales. Variation in habitat selection by...

Scientists are fallable and biased, but accuracy can be assessed through empirical analysis of published work that quantifies in-text citation (or quotation) errors. In scientific conflicts, it can be difficult for outsiders to know whose evidence or interpretation to trust. In-text citation error rate can assist decision- and policy-making bodies,...

How can humans and wildlife coexist? In the new book "Tarangire: Human-Wildlife Coexistence in a Fragmented Ecosystem", published @SpringerNature, we synthesize interdisciplinary research, highlight challenges & propose solutions that work for humans and wildlife.

The Masai giraffe is the national animal of Tanzania and a globally iconic megaherbivore, but numbers have declined precipitously and the subspecies is now listed as endangered on the IUCN Red List. We studied the Masai giraffe population in the Tarangire Ecosystem over nine years to quantify population structure and demography of a large, free-liv...

For millennia, people have lived alongside wildlife in the semi-arid savanna of the Tarangire Ecosystem (TE), northern Tanzania. The TE preserves one of the last long-distance wildlife migrations in Africa as well as a large and diverse human population. Initial wildlife conservation approaches, settlement politics, and changes in human livelihoods...

In this final chapter we summarize the contributions to the book “Tarangire: Human-Wildlife Coexistence in a Fragmented Ecosystem.” The 15 contributed chapters analyzed conservation and livelihoods issues from anthropocentric perspectives and from the wildlife lens, and explored aspects of human-wildlife interactions in the Tarangire Ecosystem (TE)...

Savanna ecosystems support the highest diversities of hoofed mammal (ungulate) species in the world. Ungulates provide critical ecosystem services such as nutrient cycling and redistribution and play a key role in the food web, yet many species of ungulates are in decline due to anthropogenic activities. The fragmented Tarangire Ecosystem supports...

Management of rangelands requires knowledge of forage species that are preferred or avoided by wildlife and livestock. A recent expansion of woody vegetation into previously open grasslands in African savanna ecosystems negatively impacts many mammalian grazers. Nevertheless, the ecological role of bush encroacher plant species as food may present...

Many social mammals form discrete social communities within larger populations. For nonterritorial, polygynous, size-dimorphic species, sex- and age-class differences in life-history requirements might mediate differences in social connectedness and transitions among communities. We conducted social network analysis and community detection with an...

Dispersal is a critical process that shapes the structure of wild animal populations. In species that form multi‐level societies, natal dispersal might be social (associating with a different social community while remaining near the natal area), spatial (moving away from the natal area while continuing to associate with the same community) or both...

The Spotted Owl is a rare and declining raptor inhabiting low/middle-elevation forests of the Pacific Northwest, California, and the Southwest in the USA. It is well established that Spotted Owls select dense, mature, or old forests for nesting and roosting. High-severity fire transforms such forests into a unique forest type known as “snag forest...

Supplemental Materials for Bond et al. Sociability increases survival of adult female giraffes

Supplementary Information for Bond et al. 2021. Socially defined subpopulations reveal demographic variation in a giraffe metapopulation.

Populations are typically defined as spatially contiguous sets of individuals, but large populations of social species can be composed of discrete social communities that often overlap in space. Masai giraffes (Giraffa camelopardalis tippelskirchi) of Tanzania live in distinct social subpopulations that overlap spatially, enabling us to simultaneou...

Studies increasingly show that social connectedness plays a key role in determining survival, in addition to natural and anthropogenic environmental factors. Few studies, however, integrated social, non-social and demographic data to elucidate what components of an animal's socio-ecological environment are most important to their survival. Female g...

Wildlife managers must be able to assess the long‐term, population‐wide impacts of mortality events on long lived vertebrates, taking into account the stochastic nature of population fluctuations. Here, we present a case study of the potential impacts on Western gulls (Larus occidentalis) of a single, non‐target mortality event, potentially resulti...

Dissent and controversy have long been recognized to play crucial roles in the production of scientific advances. However, whenever a power structure is threatened by novel ideas, we can expect gatekeepers to attempt to suppress those ideas. Interests such as money, power, status, privilege, or other advantages are powerful shapers of people’s worl...

Experimental laboratory evidence suggests that animals with disrupted social systems express weakened relationship strengths and have more exclusive social associations, and that these changes have functional consequences. A key question is whether anthropogenic pressures have a similar impact on the social structure of wild animal communities. We...

Giraffe populations have declined dramatically in the last three decades. Giraffe translocations are likely to increase as wildlife managers seek to augment or re‐establish populations. Currently, formal practical guidance for giraffe translocations is limited. Here, we present a review of translocation guidelines emphasising planning, implementati...

ABSTRACT: Most populations of giraffes have declined in recent decades, leading to the recentIUCN decision to upgrade the species to Vulnerable status, and some subspecies to Endangered.Translocations have been used as a conservation tool to re-introduce giraffes to previously occu-pied areas or establish new populations, but guidelines for foundin...

In this Chapter, we describe patterns of ungulate population dynamics, intrinsic and extrinsic causal factors underlying population growth, and consequences of variation in these causal factors in the face of anthropogenic change. We group ungulates as grazers and browsers, and review how each main functional feeding group copes with spatial and te...

Hanson et al. (2018) documented a large adverse impact of post-fire logging on an imperiled owl subspecies, the California spotted owl (Strix occidentalis occidentalis), after eight large fires in California, USA. Post-fire logging removes a unique forest type, complex early seral forest (“snag forest habitat”), which is created by high-severity fi...

Fission–fusion dynamics hypothetically enable animals to exploit dispersed and ephemeral food resources while minimizing predation risk. Disentangling factors affecting group size and composition of fission–fusion species facilitates their management and conservation. We used a 6-year data set of 2888 group formations of Masai giraffes in Tanzania...

In Peery et al.’s letter (2019) in Frontiers in Ecology and the Environment, we were accused of “agenda-driven” science with regard to our research pertaining to spotted owls and wildland fire (e.g., Hanson et al. 2018, Lee 2018). Peery et al. (2019) criticize us for stating our view that the current scientific evidence warrants increased protectio...

1 INTRODUCTION Allonursing is when mothers nurse young that are not their own. It is rarely seen in wild giraffes (Giraffa camelopardalis). Pratt and Anderson (1979) reported that of 860 observations of nursing attempts, 37 were by an unrelated calf, and just one succeeded in sustained nursing. Saito and Idani (2018) documented only five of 76 allo...

Most populations of giraffes have declined in recent decades, leading to the recent decision to upgrade the species to vulnerable status, and some subspecies to endangered. Translocations have been used as a conservation tool to re-introduce giraffes to previously occupied areas or establish new populations, but guidelines for founding populations...

In Peery et al.’s letter (2019) in Frontiers in Ecology and the Environment, we were accused of “agenda-driven” science with regard to our research pertaining to spotted owls and wildland fire (e.g., Hanson et al. 2018, Lee 2018). Peery et al. (2019) criticize us for stating our view that the current scientific evidence warrants increased protectio...

Abiotic, biotic and human influences are factors that can affect animal home ranges. We calculated home range sizes of adult giraffes in the Tarangire-Manyara region of northern Tanzania (N = 132 giraffes with data collected over 6 years), and investigated correlations between home range sizes and environmental and anthropogenic factors (for a subs...

Detailed data on individual animals are critical to ecological and evolutionary studies, but attaching identifying marks can alter individual fates and behavior leading to biases in parameter estimates and ethical issues. Individual-recognition software has been developed to assist in identifying many species from non-invasive photographic data. Th...

Most populations of giraffes have declined in recent decades, leading to the recent IUCN decision to upgrade the species to Vulnerable status, and some subspecies to Endangered. Translocations have been used as a conservation tool to re-introduce giraffes to previously occupied areas or establish new populations, but guidelines for founding populat...

Understanding the colonization or recolonization of breeding sites used by colonial animals is fundamental to metapopulation theory and has practical applications in conservation biology. Historically, pinniped species were heavily exploited worldwide, resulting in some breeding colonies becoming extirpated. As populations recover, some abandoned s...

Lee and Bond (2018)quantified ecological effects associated with the establishment of the Randelin Wildlife Management Area (WMA) in the Tarangire Ecosystem.Brehony et al.'s (2018)criticisms ofLee and Bond (2018)largely stem from problematic interpretations of what we attempted and reported. Here, we respond to Brehony et al.'s 3 criticisms. First,...

Polymorphic phenotypes of mammalian coat coloration have been important to the study of genetics and evolution, but less is known about the inheritance and fitness consequences of individual variation in complex coat pattern traits such as spots and stripes. Giraffe coat markings are highly complex and variable and it has been hypothesized that var...

Residual plots for PO regressions of spot traits Diagnostic plots generated by qqplot.

Representative spot outlines from Masai giraffes in northern Tanzania and their corresponding circularity and solidity values Ranges of spot trait values from 258 calves are given in parentheses.

Spatial distribution of the four phenotype groups of giraffe calves defined by k-means clustering of multivariate spot traits Mixed spatial distribution of calves shows no clustering by phenotype which could contribute to a shared environment effect. Mixed spatial distribution also shows permanent emigration should be random in relation to spot phe...

Summary statistics of variance explained by dimensions of a principal components analysis (PCA) of 11 giraffe spot trait variables

Pearson correlation coefficients among giraffe spot trait variables Bold correlation coefficients are statistically significant at alpha = 0.05.

Contribution of spot trait variables to principal components analysis first and second dimensions Percent contributions of each spot trait variable to the first two dimensions. P, perimeter, MC, maximum caliper, N , number of spots, C, circularity, AR, aspect ratio, R, roundness, S, solidity, FA, Feret angle.

Citation: Lee, D. E. 2018. Spotted Owls and forest fire: a systematic review and meta-analysis of the evidence. Ecosphere 9(7): Abstract. Forest and Spotted Owl management documents often state that severe wildfire is a cause of recent declines in populations of Spotted Owls and that mixed-severity fires (5-70% of burned area in high-severity patch...

Polymorphic phenotypes of mammalian coat color have been important to the study of genetics and evolution, but little is known about the heritability and fitness consequences of variation in complex coat pattern traits in wild populations. Understanding the current evolution of coat patterns requires reliably measuring traits, quantifying heritabil...

In Tanzania, community-based natural resource management of wildlife occurs through the creation of Wildlife Management Areas (WMAs). WMAs consist of multiple villages designating land for wildlife conservation, and sharing a portion of subsequent tourism revenues. Nineteen WMAs are currently operating, encompassing 7% of Tanzania's land area, with...

In fire-adapted forest ecosystems around the world, there has been growing concern about adverse impacts of post-fire logging on native biodiversity and ecological processes. This is also true in conifer forests of California, U.S.A. which are home to a rare and declining owl subspecies, the California spotted owl (Strix occidentalis occidentalis)....

Context: Managers are faced with numerous methods for delineating wildlife movement corridors, and often must make decisions with limited data. Delineated corridors should be robust to different data and models. Objectives: We present a multi-method approach for delineating and validating wildlife corridors using multiple data sources, which can b...

Spatial variation in habitat quality and anthropogenic factors, as well as social structure, can lead to spatially structured populations of animals. Demographic approaches can be used to improve our understanding of the dynamics of spatially structured populations and help identify subpopulations critical for the long-term persistence of regional...

Variation in timing of reproduction and subsequent juvenile survival often plays an important role in population dynamics of temperate and boreal ungulates. Tropical ungulates often give birth year round, but survival effects of birth season for tropical ungulate species are unknown. We used a population of giraffe in the Tarangire Ecosystem of nor...

In a recent paper in Current Biology, Fennessy and colleagues [1] conclude that there are four species of giraffe and that their numbers are declining in Africa. Giraffes (Giraffa camelopardalis) are presently classified as one species, with nine subspecies, which are considered ‘Vulnerable’ on the IUCN Red List [2]. The present consensus of one sp...

http://www.iucnredlist.org/details/full/9194/0 Giraffe (Giraffa cameloprdalis) is assessed as Vulnerable under criterion A2 due to an observed, past (and ongoing) population decline of 36-40% over three generations (30 years, 1985-2015). The factors causing this decline (levels of exploitation and decline in area of occupancy and habitat quality) h...

In long‐distance migratory systems, local fluctuations in the predator–prey ratio can exhibit extreme variability within a single year depending upon the seasonal location of migratory species. Such systems offer an opportunity to empirically investigate cyclic population density effects on short‐term food web interactions by taking advantage of th...

Population ecology studies the processes that cause the number of organisms in a population to increase or decrease. Population size through time reflects the combined outcome of three demographic processes: reproduction (births), survival (or its inverse, mortality), and movement (the combination of immigration and emigration). This article summar...

: Giraffe skin disease (GSD) is a disorder of undetermined etiology that causes lesions on the forelimbs of Masai giraffe ( Giraffa camelopardalis tippelskirchi) in Tanzania, East Africa. We examined soil correlates of prevalence of GSD from 951 giraffe in 14 sites in Tanzania, and estimated mortality using 3 yr of longitudinal mark-recapture data...

Harbor seal numbers and population trajectories differ by location in central California. Within San Francisco Bay (SFB) counts have been relatively stable since the 1972 Marine Mammal Protection Act, but in coastal areas like Tomales Bay (TB), counts increased before stabilizing in the 1990s. Emigration, poor survival, and environmental effects ha...

Giraffe skin disease (GSD) is a disorder of undetermined etiology that causes lesions on the forelimbs of Masai giraffe ( Giraffa camelopardalis tippelskirchi). We estimated occurrence and prevalence of GSD in six wildlife conservation areas of Tanzania. The disjunct spatial pattern of occurrence implies that environmental factors may influence GSD...

Forest fire is one of the most important ecological disturbances affecting habitat of the declining California spotted owl (Strix occidentalis occidentalis) population in southern California. We analyzed foraging location data collected 3 and 4 years post-fire, from 8 radio-tagged California spotted owls whose home ranges included forest burned in...

Examination of spatial variation in demography among or within populations of the same species is a topic of growing interest in ecology. We examined whether spatial variation in demography of a tropical megaherbivore followed the “temporal paradigm” or the “adult survival paradigm” of ungulate population dynamics formulated from temperate-zone stu...

Giraffe Giraffa camelopardalis are megafaunal browsers and keystone species in African savanna ecosystems. Range-wide population declines are suspected, but robust data are lacking. Tanzania holds the largest population of giraffe of any range state, and aerial surveys constitute most of Tanzania’s giraffe population monitoring data, but their accu...

Understanding interactions among site occupancy, reproduction, vegetation, and disturbance for threatened species can improve conservation measures, because important aspects of vegetation and disturbances may be identified and managed. We used 9 yr of survey data collected at 168 sites to investigate dynamic site occupancy and reproduction in a de...

PhD Dissertation Documenting whether variation in demographic parameters such as births, deaths, and movements exists, and how temporal and spatial environmental variability influences demography, is critical to understanding and affecting changes in animal populations. Natural populations often exhibit variation in demographic parameters, and whil...

High-severity forest fire often is presumed to adversely affect the occupancy of territories by California Spotted Owls (Strix occidentalis occidentalis) because these owls are associated with mature and old-growth forests. We used single-season, multi-state occupancy statistics to estimate site occupancy probability for Spotted Owls at 45 historic...

Fire over the past decade has affected forests in the San Bernardino Mountains of southern California, providing an excellent opportunity to examine how this disturbance, and subsequent post-fire salvage logging, influenced California spotted owl (Strix occidentalis occidentalis) breeding-season site occupancy dynamics there and in the nearby San J...

The northern Tarangire-Manyara Ecosystem in Tanzania is among the richest areas in the world for large mammal diversity and abundance, and Manyara Ranch provides crucial wildlife habitat for migratory and resident species between the Tarangire River and Lake Natron. This area is essential to the survival of migratory wildlife populations in the ar...

Fire is pervasive in forests used by California Spotted Owls (Strix occidentalis occidentalis) and their prey species. We assessed the diets and sizes of the breeding-season home ranges of seven Spotted Owls occupying burned forests in the southern Sierra Nevada 4 years after a fire and compared the results with data from previous studies in unburn...

Understanding how habitat disturbances such as forest fire affect local extinction and probability of colonization—the processes that determine site occupancy—is critical for developing forest management appropriate to conserving the California Spotted Owl (Strix occidentalis occidentalis), a subspecies of management concern. We used 11 years of br...

1. Photographic mark–recapture is a cost-effective, non-invasive way to study populations. However, to efficiently apply photographic mark–recapture to large populations, computer software is needed for image manipulation and pattern matching. 2. We created an open-source application for the storage, pattern extraction and pattern matching of digit...

Growth, age at maturity, and survival are life-history parameters that provide important information for understanding population dynamics. We modeled growth and age at maturity for an island population of Arboreal Salamanders, Aneides lugubris, using snout–vent length (SVL) growth intervals from a 4-yr capture–mark–recapture study fit to the von B...