• A management experiment evaluating nest-site selection by beach-nesting birds

      Swaisgood, Ronald R.; Nordstrom, Lisa A.; Schuetz, Justin G.; Boylan, Jeanette T.; Fournier, Joelle J.; Shemai, Barak (2018)
      It is important to understand nest-site selection in avian species to inform appropriate conservation management strategies. Studies of habitat selection alone, however, may be misleading unless the consequences for survival and reproduction are also documented....
    • A multi-model approach to guide habitat conservation and restoration for the endangered San Bernardino kangaroo rat

      Chock, Rachel Y.; Hennessy, Sarah McCullough; Wang, Thea B.; Gray, Emily; Shier, Debra M. (2020)
      The San Bernardino kangaroo rat (Dipodomys merriami parvus) is a federally listed endangered species endemic to Southern California and limited to three remaining populations. Its native habitat of alluvial fan sage scrub faces many anthropogenic threats, including urban and agricultural development, and the resulting flood control and fire suppression. With the loss of natural processes such as scouring or burning from floods and fires, the mosaic of seral stages across the landscape has shifted to dense vegetation, and active restoration may be necessary to provide suitable habitat for the San Bernardino kangaroo rat. Species distribution modeling using the partitioned Mahalanobis distance method on all occurrence points collected in the past 16 years revealed that alluvial scrub cover and fluvent soils were most strongly associated with San Bernardino kangaroo rat occupancy. Through surveys at 14 locations across the species’ range, we identified non-native grass cover, shrub cover, bare ground and sandy soils as microhabitat features related to San Bernardino kangaroo rat abundance. We also calculated the optimal range of cover for each habitat type that was correlated with higher kangaroo rat abundance. The results of this multiple-model approach can be used by the agencies to assess the value of conserved habitat, set targets for microhabitat enhancement to facilitate population growth and expansion, or identify receiver sites should translocation be required for recovery. This work lays the foundation for more coordinated and strategic restoration efforts, given the compressed and rigid timelines of development projects that continue to impact remaining San Bernardino kangaroo rat populations.
    • Challenges of learning to escape evolutionary traps

      Greggor, Alison L.; Trimmer, Pete C.; Barrett, Brendan J.; Sih, Andrew (2019)
      Many animals respond well behaviorally to stimuli associated with human-induced rapid environmental change (HIREC), such as novel predators or food sources. Yet others make errors and succumb to evolutionary traps: approaching or even preferring low quality, dangerous or toxic options, avoiding beneficial stimuli, or wasting resources responding to stimuli with neutral payoffs. A common expectation is that learning should help animals adjust to HIREC; however, learning is not always expected or even favored in many scenarios that expose animals to ecological and evolutionary traps. We propose a conceptual framework that aims to explain variation in when learning can help animals avoid and escape traps caused by HIREC. We first clarify why learning to correct two main types of errors (avoiding beneficial options, and not avoiding detrimental options) might be difficult (limited by constraints). We then identify and discuss several key behavioral mechanisms (adaptive sampling, generalization, habituation, reversal learning) that can be targeted to help animals learn to avoid traps. Finally, we discuss how individual differences in neophobia/neophilia and personality relate to learning in the context of HIREC traps, and offer some general guidance for disarming traps. Given how devastating traps can be for animal populations, any breakthrough in mitigating trap outcomes via learning could make the difference in developing effective solutions.
    • Cognition in a changing world: Red-headed gouldian finches enter spatially unfamiliar habitats more readily than do black-headed birds

      Mettke-Hofmann, Claudia; Eccles, Georgina R.; Greggor, Alison L.; Bethell, Emily J. (Frontiers Media SA, 2020)
      Human activities are increasingly confronting animals with unfamiliar environmental conditions. For example, habitat change and loss often lead to habitat fragmentation, which can create barriers of unsuitable and unfamiliar habitat affecting animal movements and survival. When confronted with habitat changes, animals’ cognitive abilities play an important, but often neglected part in dealing with such change. Animals must decide whether to approach and investigate novel habitats (spatial neophilia) or whether to avoid them (spatial neophobia) due to potential danger. For species with strict habitat preferences, such as the Gouldian finch (Erythrura gouldiae), which is an open habitat specialist, understanding these novelty responses may be especially important for predicting responses to habitat changes. The Gouldian finch is a polymorphic species, with primarily red or black head colors, which are linked to differing behavioral phenotypes, including novelty reactions. Here we investigate responses to novel habitats (open, dense) in the Gouldian finch, manipulating the color composition of same-sex pairs. Two experiments, each consisting of novel open and novel dense habitat, tested birds in opposite head color combinations in the two experiments. We measured the number of approaches birds made (demonstrating conflict between approach and avoidance), and their entry latency to novel habitats. Gouldian finches showed more approach attempts (stronger approach-avoidance conflict) towards the dense as compared to the open habitat, confirming their open habitat preferences. Black-headed birds also hesitated longer to enter the dense habitat as compared to the open habitat, particularly in experiment 1, appearing less neophilic than red-headed birds, which showed similar entry latencies into both habitat types. This is surprising as black-headed birds were more neophilic in other contexts. Moreover, there was some indication that pairings including at least one black-headed bird had a stronger approach-avoidance conflict than pairings of pure red-headed birds. Results suggest that the black-headed birds use a cognitive strategy typical for residents, whereas red-headed birds use a cognitive strategy known for migrants/nomads, which may cognitively complement each other. However, as 70% of the population in the wild are black-headed, the spatial wariness we document could be widespread, which may negatively affect population persistence as habitats change.
    • Communal roosting sites are potential ecological traps: experimental evidence in a Neotropical harvestman

      Grether, Gregory F.; Levi, Abrahm; Antaky, Carmen; Shier, Debra M. (2014)
      Situations in which animals preferentially settle in low-quality habitat are referred to as ecological traps, and species that aggregate in response to conspecific cues, such as scent marks, that persist after the animals leave the area may be especially vulnerable. We tested this hypothesis on harvestmen (Prionostemma sp.) that roost communally in the rainforest understory….
    • Conolophus pallidus. The IUCN Red List of Threatened Species 2020

      Gentile, G.; Grant, Tandora D. (2020)
      The Barrington Land Iguana is only found on Santa Fé (Barrington) Island, Galápagos Archipelago, Ecuador, and has an estimated area of occupancy and extent of occurrence of 40 km2 . Based on the denuded landscape caused by non-native goats, historic human consumption, and low numbers of iguanas observed in the 1960s–1970s, it is estimated that the iguana population had been reduced by at least 50% up to a point three generations in the past (52 years) and probably continued until after the goats were eradicated in 1972. The most recent survey in 2005 estimated their population to be 3,500–4,000 mature adults and potentially stable, although it was unknown if they had neared carrying capacity. Molecular analysis also shows extremely low genetic variation and richness compared to sampled populations of the Common Land Iguana (Conolophus subcristatus). Heavy predation pressure on this congregatory nesting iguana by Galápagos Hawks may have affected the rate of population recovery since goats were eradicated (1972). The recent introduction to the island of >500 juvenile Española Tortoises that compete with iguanas for scarce food resources may have an impact on the future stability of the iguana population.
    • Cyclura carinata. The IUCN Red List of Threatened Species 2020

      Gerber, Glenn P.; Colosimo, G.; Grant, Tandora D. (2020)
      Due to the persistent threat of invasive alien species, and habitat loss and degradation, Turks and Caicos Rock Iguanas currently occupy an area of about 37.1 km2 distributed among approximately 75 small islands with very little gene flow between them. This represents less than 10% of their historic range (500 km2 , >250 islands). Further, islands with abundant iguana subpopulations and no current anthropogenic threats total only 15.6 km2 . The total area of occupancy is estimated at 200 km2 using a 2x2 km grid, overlaying 20 clusters of iguana-inhabited islands. Over the last three generations (42 years), at least 11–20 island subpopulations of iguanas (including some very large islands) have been extirpated. The largest subpopulation is found on Big Ambergris Cay and is currently estimated at 6,000–7,000 mature adults (ca 25% of the total population). However, this represents a decline of 30–40% from this subpopulation's size prior to development in 1995.
    • Dietary ecology of the Nigeria–Cameroon chimpanzee (Pan troglodytes ellioti)

      Abwe, Ekwoge E.; Morgan, Bethan J.; Doudja, Roger; Kentatchime, Fabrice; Mba, Flaubert; Dadjo, Alvine; Venditti, Dana M.; Mitchell, Matthew W.; Fosso, Bernard; Mounga, Albert; et al. (2020)
      Examining the diets of primate populations inhabiting different habitat types could be useful in understanding local adaptation and divergence between these populations. In Cameroon, the Nigeria–Cameroon chimpanzee (Pan troglodytes ellioti) is subdivided into two genetically distinct populations that occupy different habitat types; one occurs in forests to the west and the other in a forest–woodland–savanna mosaic (ecotone) in the center of the country....
    • Ecological scale and seasonal heterogeneity in the spatial behaviors of giant pandas

      Zhang, Zejun; Sheppard, James; Swaisgood, Ronald R.; Wang, Guan; Nie, Yonggang; Wei, Wei; Zhao, Naxun; Wei, Fuwen (2014)
      We report on the first study to track the spatial behaviors of wild giant pandas (Ailuropoda melanoleuca ) using high‐resolution global positioning system (GPS) telemetry.... Despite a high degree of spatial overlap between panda home ranges, particularly in winter, we detected neither avoidance nor attraction behavior between conspecifics.
    • Ecology and behavior of uacaris (genus Cacajao)

      Barnett, Adrian A.; Bowler, Mark; Bezerra, Bruna M.; Defler, Thomas R.; Veiga, Liza M.; Barnett, Adrian A.; Ferrari, Stephen F.; Norconk, Marilyn A. (Cambridge University PressCambridge, 2013)
    • Effects of artificial light at night on the foraging behavior of an endangered nocturnal mammal

      Shier, Debra M.; Bird, Alicia K.; Wang, Thea B. (2020)
      ...The endangered Stephens’ kangaroo rat (SKR), Dipodomys stephensi, is a nocturnal rodent threatened by habitat destruction from urban expansion. The degree to which ALAN impacts their recovery is unknown....
    • Environmental variability supports chimpanzee behavioural diversity

      Kalan, Ammie K.; Kulik, Lars; Arandjelovic, Mimi; Boesch, Christophe; Haas, Fabian; Dieguez, Paula; Barratt, Christopher D.; Abwe, Ekwoge E.; Agbor, Anthony; Angedakin, Samuel; et al. (Springer Science and Business Media LLC, 2020)
      Large brains and behavioural innovation are positively correlated, species-specific traits, associated with the behavioural flexibility animals need for adapting to seasonal and unpredictable habitats. Similar ecological challenges would have been important drivers throughout human evolution. However, studies examining the influence of environmental variability on within-species behavioural diversity are lacking despite the critical assumption that population diversification precedes genetic divergence and speciation. Here, using a dataset of 144 wild chimpanzee (Pan troglodytes) communities, we show that chimpanzees exhibit greater behavioural diversity in environments with more variability — in both recent and historical timescales. Notably, distance from Pleistocene forest refugia is associated with the presence of a larger number of behavioural traits, including both tool and non-tool use behaviours. Since more than half of the behaviours investigated are also likely to be cultural, we suggest that environmental variability was a critical evolutionary force promoting the behavioural, as well as cultural diversification of great apes.
    • Experimental habitat restoration for conserved species using ecosystem engineers and vegetation management

      Hennessy, Sarah McCullough; Deutschman, D. H.; Shier, Debra M.; Nordstrom, Lisa A.; Lenihan, C.; Montagne, J.P.; Wisinski, Colleen L.; Swaisgood, Ronald R. (2016)
      We manipulated vegetation and the ecosystem engineer California ground squirrel, Otospermophilus beecheyi, in a replicated, large-scale field experiment for 2 years, and monitored through a third year…. The overarching goal of this experiment was to provide conservation managers with a cost-effective tool for restoring degraded habitats to a hybrid ecosystem state with improved suitability for species of conservation concern, in this case, the western burrowing owl Athene cunicularia hypugaea.
    • Fitness costs associated with ancestry to isolated populations of an endangered species

      Wilder, Aryn P.; Navarro, Asako Y.; King, Shauna N. D.; Miller, William B.; Thomas, Steven M.; Steiner, Cynthia C.; Ryder, Oliver A.; Shier, Debra M. (2020)
      ... The endangered Pacific pocket mouse (Perognathus longimembris pacificus) persists in three isolated populations in southern California. Mitochondrial and microsatellite data indicated that effective population sizes were extremely small (Ne< 50), and continued declines prompted a conservation breeding program founded by individuals from each population....
    • Functional habitat heterogeneity and large herbivore seasonal habitat selection in Northern Botswana

      Fynn, Richard W.S.; Chase, Michael J.; Röder, Achim (2014)
      This study aimed to determine the functional seasonal attributes for herbivores of the major habitats and landscapes of the Savuti-Mababe-Linyanti ecosystem (SMLE) of northern Botswana and how various herbivore species responded to this heterogeneity. Floodplain grasslands and dambo grasslands provided the only significant green forage and biomass during the late dry season, whereas short grasslands of the Mababe Depression provided the highest forage quality of all habitats during the wet season....
    • Giant panda distributional and habitat-use shifts in a changing landscape

      Wei, Wei; Swaisgood, Ronald R.; Dai, Qiang; Yang, Zhisong; Yuan, Shibin; Owen, Megan A.; Pilfold, Nicholas W.; Yang, Xuyu; Gu, Xiaodong; Zhou, Hong; et al. (2018)
      Long‐term data on populations, threats, and habitat‐use changes are fundamentally important for conservation policy and management decisions affecting species, but these data are often in short supply. Here, we analyze survey data from 57,087 plots collected in approximately three‐fourths of the giant panda's (Ailuropoda melanoleuca) distributional range during China's national surveys conducted in 1999–2003 and 2011–2014. Pandas associated preferentially with several ecological factors and avoided areas impacted by human activities, such as roads, livestock, mining, and tourism. Promise is shown by dramatic declines in logging rates, but is counterbalanced with recently emerging threats. Pandas have increasingly utilized secondary forest as these forests recovered under protective measures. Pandas have undergone a distributional shift to higher elevations, despite the elevational stability of their bamboo food source, perhaps in response to a similar upward shift in the distribution of livestock. Our findings showcase robust on‐the‐ground data from one of the largest‐scale survey efforts worldwide for an endangered species and highlight how science and policy have contributed to this remarkable success story, and help frame future management strategies.
    • Habitat utilization of Roatán Spiny-tailed Iguanas (Ctenosaura oedirhina) and its implications for conservation

      Goode, A.B.C.; Pasachnik, Stesha A.; Maple, T.L.; Iverson, John B.; Grant, Tandora D.; Knapp, Charles R.; Pasachnik, Stesha A. (2016)
      ...With data gathered from use/availability surveys, resource selection functions can identify habitats and environmental variables associated with the presence of a species. Herein, we used these techniques to better understand the distribution of the Roatán Spiny-tailed Iguanas (Ctenosaura oedirhina), a narrow-range endemic on the island of Roatán, Honduras....
    • Hiding in plain sight: a study on camouflage and habitat selection in a slow-moving desert herbivore

      Nafus, Melia G.; Germano, Jennifer M.; Perry, Jeanette A.; Todd, Brian D.; Walsh, Allyson; Swaisgood, Ronald R. (2015)
    • Identifying priority conservation landscapes and actions for the Critically Endangered Javan leopard in Indonesia: Conserving the last large carnivore in Java Island

      Wibisono, Hariyo Tabah; Wahyudi, Hariyawan Agung; Wilianto, Erwin; Pinondang, Irene Margareth Romaria; Primajati, Mahendra; Liswanto, Darmawan; Linkie, Matthew (2018)
      With the extirpation of tigers from the Indonesian island of Java in the 1980s, the endemic and Critically Endangered Javan leopard is the island’s last remaining large carnivore. Yet despite this, it has received little conservation attention and its population status and distribution remains poorly known. Using Maxent modeling, we predicted the locations of suitable leopard landscapes throughout the island of Java based on 228 verified Javan leopard samples and as a function of seven environmental variables. The identified landscapes covered over 1 million hectares, representing less than 9% of the island. Direct evidence of Javan leopard was confirmed from 22 of the 29 identified landscapes and included all national parks, which our analysis revealed as the single most important land type. Our study also emphasized the importance of maintaining connectivity between protected areas and human-modified landscapes because adjacent production forests and secondary forests were found to provide vital extensions for several Javan leopard subpopulations. Our predictive map greatly improves those previously produced by the Government of Indonesia’s Javan Leopard Action Plan and the IUCN global leopard distribution assessment. It shares only a 32% overlap with the IUCN range predictions, adds six new priority landscapes, all with confirmed presence of Javan leopard, and reveals an island-wide leopard population that occurs in several highly fragmented landscapes, which are far more isolated than previously thought. Our study provides reliable information on where conservation efforts must be prioritized both inside and outside of the protected area network to safeguard Java’s last remaining large carnivore.